Chronological List of Articles

SUMMARY:
This study evaluated the long-term clinical performance of a self-etching adhesive system, Clearfil Liner Bond 2. Two operators placed a total of 87 restorations among 42 patients. Carious dentin was identified with the help of Caries Detector and was removed using only a low speed round bur. Clearfil Liner Bond 2 was applied following the manufacturer’s directions, and the resin composite was then placed. The number of restorations placed by cavity classification were: 8–Class I, 11–Class II, 21–Class III, 2–Class IV and 45–Class V. The restorations were evaluated in 5 categories according to modified USPHS criteria: pulpal response, marginal integrity, marginal discoloration, retention and secondary caries. Assessments were done at baseline, immediately after placement and at 6-months and 1, 5, 7 and 10 years. Recall rates at each assessment period were 83.9% (6-months), 82.8% (1 year), 59.8% (5 years), 77.0% (7 years) and 50.6% (10 years). In terms of assessment categories, there were no recorded sensitivity, retention loss or secondary caries at any of the five recall periods. At the 10-year assessment, 40 out of 44 restorations (90.9%) were rated Bravo for marginal integrity and 39 restorations (88.6%) were rated Bravo for marginal discoloration (Wilcoxon signed-ranks test p<0.05). This data demonstrates the retention rate and pulpal response of the self-etching adhesive system Clearfil Liner Bond 2 was excellent at 10 years. Most cases showed slight marginal changes during clinical function; however, these changes were not clinically severe by USPHS criteria. These data demonstrate that placement of the Clearfil Liner Bond 2 self-etching adhesive system was demonstrated to be acceptable for the clinical restoration of human teeth following 10 years of clinical function.

SUMMARY:
The use of adhesive materials to restore non-carious cervical lesions (NCCL) has become the standard practice. Until recently, the most reliable material for restoring NCCL is glass ionomer cement, but the esthetics can be problematic. This study compared the retention of a self-etching adhesive, Clearfil SE Bond, with Clearfil ST resin composite (SE), with the phosphoric acid-etch single bottle adhesive Single Bond with A110 resin composite (SB) and a resin-modified glass ionomer cement, Fuji II LC, (FJ). Ninety-two restorations in 20 patients (mean age 61 years) were placed. The teeth were restored randomly and manufacturers’ instructions were followed. Patients were recalled at 6 months, 1, 2 and 3 years and the restorations were evaluated for marginal staining. The restorations were photographed at baseline and at recall periods. At one year, 80 restorations were available for evaluation; at 2 years, 65 restorations were evaluated and at 3 years, 55 restorations were evaluated. The cumulative retention rates at 1 year, 2 years and 3 years, respectively, were SE: 97%, 93%, 90%; SB: 86%, 77%, 77%; FJ: 100%, 100%, 97%. At 3 years, RM-GIC performed the best, followed by Clearfil SE Bond/Clearfil ST. Single Bond/A110’s performance was significantly less than the other 2 materials (p=0.012).

SUMMARY:
This study evaluated the effect of collagen removal and sodium ascorbate treatment of acid-etched dentin on the microleakage and ultrastructure of resin-tooth interface under moist and dry conditions using an acetone-based 1 bottle adhesive system. Class V cavities were made on the buccal surfaces of 90 premolars scheduled for orthodontic extraction. The cavities were etched with 37% phosphoric acid (DPI tooth conditioning gel/India) for 15 seconds. The teeth were divided into six groups with 15 teeth each. In Group 1, the etched surface was blot dried with a dry cotton pellet, leaving it visibly moist, and Prime & Bond NT (Dentsply Detrey/ Germany) was applied. In Group 2, after acid conditioning, the cavity surface was air dried for five seconds, followed by application of Prime & Bond NT. In Group 3, 3% NaOCl (Hyposol, Prevest Denpro Ltd/India) was applied to the acid-conditioned cavity surface for two minutes. The surface was blot dried before bonding. In Group 4, after NaOCl treatment, the surface was air dried for five seconds, followed by application of the bonding agent. In Group 5, 10% sodium ascorbate (chemically pure) was applied to the NaOCl-treated acid conditioned tooth surface for one minute. The surface was blot dried before bonding. In Group 6, after sodium ascorbate treatment as in Group 5, the cavity surface was air dried for five seconds before bonding. The cavities were restored with the hybrid composite Spectrum TPH (Dentsply Detrey, Konstanz, Germany). The teeth were extracted immediately after restoration, and the specimens were prepared for microleakage testing using 2% methylene blue dye and for scanning electron microscopic evaluation. The results of the dye penetration were analyzed with Kruskal-Wallis non-parametric analysis followed by the Mann-Whitney U test at a significance level of p=0.05. After acid etching, the conventional acid etched groups and groups with NaOCl treatment demonstrated extensive leakage. Sodium ascorbate treatment of the NaOCl-treated dentin significantly reduced microleakage. No statistically significant difference between moist and dry bonding was observed in all groups. Although resin tag penetration improved in both the NaOCl-treated and NaOCl/ascorbate-treated groups, an absence of gap at the resin dentin interface was observed only for the NaOCl/ascorbate-treated groups.

SUMMARY:
This study evaluated the ability of two self-etching adhesives (a two-step and a one-step) and a conventional 3-step adhesive to bond composite to both intact and caries-affected dentin with and without thermocycling. Thirty extracted human teeth with occlusal caries were randomly assigned to three groups according to the adhesive used: Scotchbond Multi-purpose (3M) (SBMP), ClearfilSE Bond (Kuraray) (SE) and Xeno IV (Dentsply) (XEIV). The occlusal surfaces of the teeth were sectioned to expose dentin. The adhesives were applied according to manufacturers’ instructions, and a composite material (Herculite XRV, Kerr) was applied and cured in increments to form a core 3 mm high. The teeth were stored in distilled water for 24 hours, then sectioned using a micro-slicing machine to obtain sections 1 mm thick. The sections were further cut to obtain rods 6 mm long and 1 x 1 mm in thickness, with dentin/composite interface located at the center. The specimens were examined microscopically to separate the caries-affected (AD) and sound dentin (SD) into two groups. Half the specimens from each group were subjected to 3,000 thermocycles (5°C to 55°C) prior to testing. All the specimens were then subjected to microtensile bond strength (µTBS) testing in a special apparatus. Mean µTBS was determined for each group, and data were statistically analyzed with ANOVA and Tukey’s tests. Mean µTBS and standard deviation values in MPa were: SBMP-SD = 22.19 (4.6), SBMP-SD-thermocycled = 15.7 (5.55), SBMP-AD = 18.6 (2.89), SBMP-AD-thermocycled = 16.62 (6.23), SE-SD = 24.25 (5.7), SE-SD-thermocycled = 22.3 (6.7), SE-AD = 20.7 (5.55), SE-AD-thermocycled = 20.23 (6.1), XEIV-SD = 21.43 (7.6), XEIV-SD-thermocycled = 18.3 (7.11), XEIV-AD = 15.45 (6.62), XEIV-AD-thermocycled = 14.8 (3.89). ANOVA revealed a significant difference among the groups (p<.0001). The two-step self-etch adhesive resulted in highest mean µTBS values under all test conditions. However, these mean values were significantly higher than the mean values obtained with the other two adhesives under some, but not all test conditions.

SUMMARY:
This study compared the bond strength of two resin cements to human root dentin when used with three bonding agents. The materials used were Rely X ARC and Perma Cem, two one-bottle bonding agents (Single Bond, Bond-1) and one self-etching bonding agent (Clearfil SE Bond).

The dentin was obtained from single rooted human teeth, and the specimens were treated with either 15% EDTA or 37% phosphoric acid to remove the smear layer, except in groups where the self-etching bonding agent was used. The resin cements were placed on dentin surfaces with the use of bonding agents. Shear bond strength (SBS) was tested using a single plane shear test assembly.

The dentin specimens were divided into 10 groups. Eight groups were pre-treated with EDTA or phosphoric acid to remove the smear layer, followed by a bonding agent (Bond-1 or Single Bond) and resin cement (Rely X or Perma Cem). In the two remaining groups, the smear layer was left intact, and the two resins cements were used in combination with the self-etching bonding agent (Clearfil SE Bond).

No statistically significant differences were observed among the eight groups treated with one- bottle bonding agents. The mean bond strengths of the two groups treated with the self-etching bonding agent did not differ significantly from each other but were both significantly greater than the bond strengths of all the other groups.

The results of this study also showed that EDTA can be used as an alternative to phosphoric acid in bonding procedures for resin cements. However, the bond strengths of resin cements, in combination with a self-etching bonding agent, were significantly greater than those of the same cements when used with one-bottle bonding agents.

SUMMARY:
This study evaluated the microtensile bond strength (µTBS) of dual-cured adhesive systems when the different components were either light activated or left in the uncured state prior to cementation of an indirect composite restoration. Occlusal dentin surfaces of 40 human third molars were flattened. The teeth were randomly assigned to 8 groups (n=5) according to the dual-cured systems (bonding agents/resin cements) and curing modes: All Bond 2/Duolink (AB2-BISCO Inc) and Optibond Solo Plus Dual Cure/Nexus 2 (SOLO-Kerr). Resin cements were applied to pre-cured resin composite discs (2 mm thick/Z-250/3M ESPE), which were fixed to dentin surfaces containing adhesive resin in either cured (LP) or uncured states (SP). The restored teeth were light activated according to the manufacturers’ instructions (LRC-XL3000/3M ESPE) or allowed to self-cure (SRC). The restored teeth were water-stored at 37°C for 24 hours. They were then both mesial-distally and buccal-lingually sectioned to obtain bonded specimens (1.2 mm2). Each specimen was tested in tension at a crosshead speed of 0.6 mm/minute until failure. Data (MPa (SD)) were analyzed by two-way ANOVA and Tukey’s post-hoc test (p<.05). AB2/SP exhibited higher µTBS than AB2/LP (p=.00001); however, no significant differences were noted between SOLO/LP and SOLO/SP. Results suggested that dual-cured adhesive systems were as strong or even stronger when they were left in the uncured state prior to indirect resin composite cementation.

SUMMARY:
This study evaluated the surface geometry of four nanocomposites and 1 hybrid composite after finishing with rigid rotary instruments.

Four nanofilled composites (Premise, KerrHawe; Tetric EvoCeram, Ivoclar Vivadent; Filtek Supreme, 3M ESPE; Ceram X Duo, Dentsply) and one hybrid composite (Herculite XRV, KerrHawe) were used for the study. Sixty specimens were made of each product, 7x7 mm in size. Fifteen specimens of each composite were subjected to the following finishing procedures: a 30 µm diamond (FM1), a sequence of a 30 µm and a 20 µm diamond (FM 2) and a 30 µm diamond followed by a 12-fluted tungsten carbide finishing bur (FM 3). As a reference, 15 other specimens of each material were treated with Sof-Lex discs. Evaluation of the surfaces was done with laser-stylus profilometry. Roughness parameters were average roughness (Ra) and profile-length ratio (LR). Statistical analysis of the data was performed by two-way and one-way ANOVA and post-hoc tests by Scheffé. Additional qualitative assessment of the finished composite surfaces was done by scanning electron microscopy (SEM) at a tension of 25 kV.

The composite materials and the finishing methods had a significant effect on surface roughness (p<0.001 for Ra and LR). There were significant interactions between the materials and the finishing methods (p<0.001 for Ra and LR). Compared to Herculite XRV, three of the nanocomposites were significantly smoother after finishing, according to FM 1-3 and after application of the Sof-Lex discs. Ceram X Duo and Herculite XRV had similar surface roughness in terms of Ra and LR. Compared to a single 30 µm diamond and a sequence of two diamonds (FM 2), significantly lower roughness values on all composites were achieved by using a 30 µm diamond followed by a tungsten carbide instrument (p<0.001 for Ra and LR). Ra- and LR-values after FM 3 were similar or, in some cases, even lower than surface roughness measured after application of Sof-Lex discs. Evaluation by SEM revealed that the use of a 30 µm diamond caused detrimental surface alteration on all types of composites. A remarkable number of porosities were detected on 1 of the nanofilled composites.

SUMMARY:
This study evaluated the effects of water-storage on the water sorption and solubility behavior of five commercially available dental adhesive systems and two primer/adhesive mixtures. The adhesives comprised three different approaches to bonding to hard tooth tissues: a one-step self-etching adhesive (One-up Bond F), two two-step self-etching primers (Clearfil SE Bond and Clearfil Protect Bond) and two etch-and-rinse systems: a water/ethanol-based (Single Bond) and an acetone-based filled adhesive (Prime&Bond NT). The bonding agents and primers of the two-step self-etching systems were mixed in a 1:1 volume ratio. Water sorption and solubility values were determined after 1, 7, 30, 90 and 180 days. The results showed that, except for SB, all adhesives presented increased water sorption with increased storage time. The one-step self-etching adhesive and self-etching primer/adhesive mixtures presented the highest water sorption and solubility values. Equilibrium in the water sorption values was observed for all adhesives after 90 days of water-storage. However, solubility values continued to increase for some materials until 180 days. The sorption and solubility behavior of the materials tested seem to be related to hydrophilicity of the adhesive resin solution and might influence the long-term performance of resin-based composite restorations.

SUMMARY:
This in vitro study investigated the correlation between factors related to cavosurface marginal adaptation and microleakage in Class II cavities restored with a light- or chemical-activated resin composite. Standardized cavities were prepared in 40 molars that were randomly divided between both materials. Each of the groups was, in turn, divided, so that the restorations were placed by incremental and bulk techniques. The resultant four groups (n=10), each with material/technique variations, had their marginal gaps measured by environmental scanning electron microscopy at randomly selected facial and lingual points of the proximal box of each restoration. After sectioning the teeth, interfacial dye penetration was assessed by light stereomicroscopy according to an ordinal scale at the same locations as for the marginal gaps. In a general linear model with microleakage as a dependent variable, no correlation between marginal gap size and microleakage was found (p=0.802), although the interaction of the material and placement technique (p=0.028) and material alone (p=0.063) influenced microleakage. The model explained 63% of the variation in microleakage. It was concluded that, irrespective of the possible role of marginal gap in the occurrence of microleakage, the choice of material and placement technique are important determining factors in microleakage.

SUMMARY:
This in vitro study evaluated the coronal and apical marginal microleakage of four self-etch, seventh generation adhesive systems.

Sixty non-carious human molars were randomly assigned to four groups (n=12). Class V cavities were prepared on the facial or lingual surface of each tooth with coronal margins in enamel and apical margins in cementum (dentin) at the cementoenamel junction. The preparations were restored using four self-etch adhesive systems (iBond, G-Bond, Xeno IV and Clearfil S3 Bond) and a control (no adhesive), followed by insertion of Gradia Direct microfilled hybrid resin composite. The teeth (specimens) were thermocycled 1,000 cycles, immersed in 1% methylene blue dye for 24 hours and invested in acrylic resin. The specimen blocks were then sectioned longitudinally, with dye penetration (microleakage) examined using a 20x binocular microscope. Coronal and apical margins were scored separately for microleakage using a 0-3 ordinal ranking system. Data were analyzed using non-parametric tests at a p<0.05 level of significance. A comparison of adhesive and control groups at the coronal and apical margins revealed that significant (p<.0001) differences were exhibited. At the coronal margin, Xeno IV revealed significantly less leakage than the other adhesives, with Clearfil S3 Bond exhibiting significantly less leakage at the apical margin. Groups with no adhesive treatment (control) showed significantly greater leakage at both the coronal and apical margin locations. A Wilcoxon signed rank test showed no significant differences at the coronal compared to the apical margins of the four adhesive systems and control tested.

SUMMARY:
This study investigated the influence of thermal cycling on the dentin bond strengths of single-step self-etch adhesive systems. The Absolute, Clearfil Tri-S Bond, G-Bond and One-Up Bond F Plus systems were used. Bovine mandibular incisors were mounted in self-curing resin, and the facial surfaces were wet ground with #600 SiC paper. Adhesives were applied to the prepared dentin surfaces, and they were light irradiated according to each manufacturer’s instructions. Resin composites were condensed into a mold (4 mm in diameter and 2 mm in height) and light irradiated for 30 seconds. Bonded specimens were divided into three groups and subjected to different storage conditions as follows: 37°C water for 24 hours; 37°C water for 24 hours followed by 10,000 thermal cycles between 5°C and 60°C or 37°C water for 24 hours followed by 20,000 thermal cycles between 5°C and 60°C. Ten samples per group were tested in a shear mode at a crosshead speed of 1.0 mm/minute. Analysis of variance and Tukey’s HSD test at the 0.05 significance level were used to compare the three storage conditions for each adhesive system. After 24 hours storage in water, the mean dentin bond strengths ranged from 11.4 MPa to 17.1 MPa. The Clearfil Tri-S Bond system showed the highest bond strength. After 10,000 thermal cycles, the mean bond strengths remained unchanged except for those of the Clearfil Tri-S Bond system, which significantly increased. Significant decreases in bond strength were observed for the Absolute and One-Up Bond F Plus systems after 20,000 thermal cycles. Failure mode was commonly due to adhesive breakdown associated with partial cohesive failure of the adhesive resin. From the results of this study, in terms of simplifying the clinical procedure, the benefit of using single-step self-etch systems might be acceptable.

SUMMARY:
This study analyzed the depth of cure of a composite assessed by microhardness and the degree of conversion as a function of the light cure unit (LCU) used. Two light cure units, one LED (Ultraled–Dabi Atlante) and one quartz-tungsten-halogen (QTH, Optilux 401–Demetron) unit were used to cure 4.0 x 4.0 mm and 5.0 mm deep composite specimens (Filtek Z250, 3M ESPE). After 24 hours storage at 37°C, Knoop microhardness and degree of conversion were measured on the irradiated surface and at each millimeter of the sample’s depth. The degree of conversion was determined by using micro-Raman spectroscopy. The specimens cured with the QTH unit presented uniform decay in microhardness up to 4 mm in depth. Beyond 4 mm, the drop was abrupt. With LED photoactivation, uniform decay was observed only up to 2 mm. At higher depths, the decay in microhardness increased rapidly, especially beyond 3 mm. Depth of cure assessed by micro-Raman revealed that the degree of conversion behaved similarly to microhardness for both LCUs. A strong linear regression between microhardness and the degree of conversion, including both LCUs, was established with R2=0.980.

SUMMARY:
This study evaluated the effect of two different types of provisional luting agents (RelyX Temp E, eugenol-based; RelyX Temp NE, eugenol-free) on the shear bond strengths between human dentin and two different resin-based luting systems (RelyX ARC-Single Bond and Duo Link-One Step) after cementation with two different techniques (dual bonding and conventional technique). One hundred human molars were trimmed parallel to the original long axis, to expose flat dentin surfaces, and were divided into three groups. After related surface treatments for each specimen, the resin-based luting agent was applied in a silicone cylindrical mold (3.5 x 4 mm), placed on the bonding-agent-treated dentin surfaces and polymerized. In the control group (n=20), the specimens were further divided into two groups (n=10), and two different resin-based luting systems were immediately applied following the manufacturer’s protocols: RelyX ARC-Single Bond (Group I C ) and Duo Link-One Step (Group II C). In the provisionalization group (n=40), the specimens were further divided into four subgroups of 10 specimens each (Group I N, I E and Group II N, II E). In Groups I N and II N, eugenol-free (RelyX NE), and in groups I E and II E, eugenol-based (RelyX E) provisional luting agents (PLA), were applied on the dentin surface. The dentin surfaces were cleaned with a flour-free pumice, and the resin-based luting systems RelyX ARC (Group I N and E) and Duo Link (Group II N and E) were applied. In the Dual bonding groups (n=40), the specimens were divided into four subgroups of 10 specimens each (Group I ND, ED and Group II ND, ED). The specimens were treated with Single Bond (Groups I ND and ED) or One Step (Groups II ND and ED). After the dentin bonding agent treatment, RelyX Temp NE was applied to Groups I ND and II ND, and RelyX Temp E was applied to Groups I ED and II ED. The dentin surfaces were then cleaned as described in the provisionalization group, and the resin-based luting systems were applied: RelyX ARC-Single Bond (Group I ND and ED) and Duo Link-One Step (Group II ND and ED). After 1,000 thermal cycles between 5°C and 55°C, shear bond testing was conducted at a crosshead speed of 0.5 mm/minutes. One-way ANOVA, followed by a post hoc Tukey test (a=0.05) was done. The dentin-resin-based luting system interfaces were evaluated under a scanning electron microscope. There was a significant reduction in the mean shear bond strength values of groups subjected to the provisionalization compared to the control and dual bonding technique groups (p<0.05). The composition of provisional luting did not create a significant difference with regard to reducing shear bond strength values (p>0.05). With regard to resin based luting systems, the shear bond strength values of the double-bond technique groups were not significantly different from the controls (p>0.05).

SUMMARY:
In large posterior cavities, indirect restorations could provide improved performance when compared to direct restorations, but with higher cost and removal of sound tooth structure. Improved mechanical properties have resulted in good clinical performance for amalgam in large cavities but without an esthetic appearance. Resin composites have become popular for posterior restorations, mainly because of good esthetic results. A restorative technique is presented that combines the esthetic properties of directly bonded resin composite and the wide range of indications for amalgam in stress-bearing areas.

David O Moline, DDS

Dr Richard Hoard

SUMMARY:
This in vivo study evaluated by TEM the degradation of dentin hybrid layers in deep occlusal resin composite restorations. Caries-free premolars scheduled for extraction as part of orthodontic treatment were prepared, restored and evaluated after two and six months. The adhesive used was a single-bottle etch-and-rinse product (Single Bond Plus, 3M ESPE). Control group restorations were placed according to the manufacturer’s instructions, while the experimental group received application of a 2% solution of chlorhexidine digluconate after etching. No degradation was observed in either group after two months. Slight degradation was found in the control group after six months, but none was observed in the experimental group. In vitro testing showed no significant difference in microtensile bond strength between the control and experimental adhesive protocols.

SUMMARY:
Historically, postoperative pain associated with temperature was considered a thermal conduction problem. More recently, pulpal hydrodynamics has been used to explain this sensitivity. Relative to restorations placed with dentin bonding agents that require a separate etching step, agents that include an acidic primer are believed to result in a better seal of the dentinal tubules. This study compared pain associated with a standardized cold stimulus in two groups of restorations. One group was placed with a self-priming resin that required a separate etch step, the other with a self-etching, self-priming dentin bonding agent.

This was a community-based, randomized, double-blind clinical trial. Two hundred and nine restorations were placed for 76 participants. All teeth were asymptomatic at the start of the trial. Immediately following application of a standardized cold stimulus, participants rated the pain for each restored tooth using a Visual Analog Scale (VAS). For each group of restorations, VAS scores at 13 weeks were compared to preoperative scores. In addition, the preoperative score was subtracted from the 13-week score, and the two groups of restorations were compared.

For both groups of restorations, the median scores were significantly reduced at 13 weeks. This decrease in the VAS score reflects a reduction in sensitivity below that which existed preoperatively. There was no significant difference between the two groups of restorations in terms of change in sensitivity at 13 weeks.

SUMMARY:
This study evaluated the clinical performance and wear resistance of compomer restorations placed in the occlusal cavities of posterior permanent teeth after six years. In 1999, 72 Class I restorations were placed by a single operator in 33 patients. Eighty-two percent of these restorations were located in molars. Each patient received at least two restorations, one with F2000 (3M ESPE) and another with Dyract AP (Dentsply). The finished and polished restorations that were free of any failure were considered the baseline. The restorations were clinically evaluated at baseline and at one-, two- and six-year intervals using modified USPHS criteria for color mismatch, marginal discoloration, surface roughness, marginal adaptation, anatomic form and secondary caries. Polyvinylsiloxane impressions (Express, 3M ESPE) were also taken, and models were obtained for indirect wear assessment (Leinfelder scale) at the same intervals. After six years, 11 patients attended the recall. Twenty-seven compomer restorations (11 with Dyract and 16 with F2000) were reevaluated. Data were submitted to the Friedman’s test, ANOVA with repetitive measures, Tukey’s test (clinical data), Wilcoxon and Kruskal-Wallis tests and the Spearman’s correlation test (wear evaluation), all at a significance level of p<0.05. When comparing the materials, F2000 and Dyract presented similar clinical performance and occlusal wear at the end of the clinical trial. The two compomers showed a significant increase in wear at the six-year follow-up, and a positive correlation (r2=0.65) was detected between wear and evaluation time (p<0.001). Despite the decrease in restoration quality and the increase in occlusal wear, nearly all restorations were considered acceptable after the six-year evaluation.

SUMMARY:
This study investigated the effect of three equivalent radiant exposure energy application sequences (EASs): high intensity power (HIP: 1,177 mW/cm2, 40 seconds), low intensity power (LOP: 573 mW/cm2, 71 seconds) and ramp (RMP: 650 mW/cm2, 5 seconds, then the irradiance increases to 1047 mW/cm2, 37 seconds) on the microtensile bond strength (MTBS) in both low and high C-factor cavity preparations. Thirty Paradigm blocks (Z100) were mounted in stone, with their top surfaces parallel to the mounting block. High C-factor (HC=3.8) Class I cavity preparations were then prepared in 15 of the Paradigm blocks using a computer-controlled specimen former. Low C-factor (LC = 1.8) Class II cavity preparations were prepared in the remaining 15 blocks by sectioning them perpendicularly using a slow-speed diamond saw. Five samples, one from each experimental group (3 EASs x 2 C-factors), were prepared and stored in the dark for 48 hours in distilled water at 37°C prior to MTBS testing on the third day and on the remainder of the samples (n=30). Mode of fracture was determined with a stereomicroscope at 20-40x magnification. The findings of this study indicated that HC, in combination with HIP, had significantly lower bond strength (27.54 MPa) than LC with HIP (51.39 MPa). On the other hand, there was no significant difference between high and low C-factors with the other EASs (LOP or RMP). There was also no significant effect for EAS (HIP, RMP and LOP), with C-factor (HC or LC) held constant. The HIP-HC group had the highest percentage of adhesive (20%) and mixed adhesive (50%) failures (70% total). Adhesive and mixed adhesive failures occurred in other groups, but with lower percentages (RMP-LC: 40% total) (LOP-HC: 40% total).

SUMMARY:
This study investigated the microtensile bond strength (µTBS) of a one-step self-etching adhesive to human dentin and bovine enamel following different bonding treatments. Occlusal portions of human molars and labial surfaces of bovine incisors were ground flat to provide uniform dentin and enamel surfaces, respectively. Futurabond was used following five different protocols: 1) according to the manufacturer’s directions, 2) acid etched with 36% phosphoric acid (H3PO4) for 15 seconds, 3) 10% sodium hypochlorite (NaOCl) treated for two minutes after H3PO4-etching, 4) doubling the application time of the adhesive and 5) doubling the number of adhesive coats. Composite build-ups (6 mm in height) were constructed incrementally with Arabesk resin composite. The specimens were stored in 100% humidity for 24 hours at 37°C and sectioned into beams of 1.0 mm2 cross-sectional area. Each beam was tested in tension in an Instron machine at 0.5 mm/minute, and mean µTBS data (MPa) were analyzed by one-way ANOVA and post-hoc multiple comparisons tests (a=0.05). Doubling the application time of Futurabond attained the highest µTBS to dentin; whereas, no differences among all bonding application parameters evaluated could be detected when the adhesive was applied to enamel.

SUMMARY:
This study investigated the effects of environmental temperature on the fluoride release and recharging ability of glass ionomers. Five disk specimens (15 mm in diameter and 1 mm thick) were made of each of the following materials: a conventional luting glass ionomer, two high viscosity restorative glass ionomers and a restorative resin-modified glass ionomer. The fluoride release of each material was measured at 4°C, 37°C and 55°C. An additional three groups, which were made of the same materials, were stored in distilled and deionized water for 30 days and recharged in 250 ppm fluoride solution at 4°C, 37°C and 55°C for five minutes. The fluoride re-release was measured daily from two days prior to two days after the recharging process. At all temperatures, the luting glass ionomers showed the greatest fluoride release and recharging ability, followed by the resin-modified glass ionomer, then the high viscosity glass ionomers. For each material, the fluoride release increased with increasing temperature and all glass ionomers showed greater recharging ability at higher temperatures. An increase in environmental temperature increased both the fluoride release and recharging of the glass ionomers. This may be important in developing regimes for improving the delivery of topical fluoride products.

SUMMARY:
This study determined whether the strength with which resin composite bonds to dentin is influenced by variations in the curing rate of resin composites. Resin composites were bonded to the dentin of extracted human molars. Adhesive (AdheSE, Ivoclar Vivadent) was applied and cured (10 seconds @ 1000 mW/cm2) for all groups. A split Teflon mold was clamped to the treated dentin surface and filled with resin composite. The rate of cure was varied, using one of four LED-curing units of different power densities. The rate of cure was also varied using the continuous or pulse-delay mode. In continuous curing mode, in order to give an energy density totaling 16 J/cm2, the power densities (1000, 720, 550, 200 mW/cm2) emitted by the various curing units were compensated for by the light curing period (16, 22, 29 or 80 seconds). In the pulse-delay curing mode, two seconds of light curing at one of the four power densities was followed by a one-minute interval, after which light cure was completed (14, 29, 27 or 78 seconds), likewise, giving a total energy density of 16 J/cm2. The specimens produced for each of the eight curing protocols and two resin composites (Tetric EvoCeram, Ivoclar Vivadent; Filtek Supreme XT, 3M ESPE) were stored in water at 37°C for seven days. The specimens were then either immediately subjected to shear bond strength testing or subjected to artificial aging (6,000 cycles between 5°C and 55°C baths) prior to testing. Failure modes were also assessed. The shear bond strengths were submitted to factorial analysis of variance, and the failure modes were submitted to a Chi-square test (a=0.05). All but power density (curing mode, resin composite material and mode of aging) significantly affected shear bond strength. The curing mode and resin composite material also influenced the failure mode. At the selected constant energy density, pulse-delay curing reduced bonding of the resin composite to dentin.

SUMMARY:
This study determined the effects of bonding agents on the shear bond strength of dual- and self-cured resin composites to dentin. Two light-cured dentin bonding agents (Excite and One-Step) and a dual-cured bonding agent (Excite DSC) were compared. Light activation of the bonding agents prior to placement of the resin composites was also evaluated. This in vitro study was performed on 120 extracted non-carious human third molars. The occlusal part of the crowns was removed to expose a flat dentin surface. The teeth were then randomly divided into three major groups for Excite, One-Step and Excite DSC as bonding agents. The specimens in each adhesive group were divided into four subgroups: with and without light activation of the bonding agent and with dual-cured (Luxacore Dualcure, DMG, Hamburg, Germany) or light-cured resin (Luxacore, DMG, Hamburg, Germany) composites. After placing the restorations, the specimens were kept in water at 37°C for 24 hours before being tested for shear bond strength on an Instron universal testing machine at a crosshead speed of 0.5 mm/minute. The results showed that the shear bond strength of dual-cured resin composite to dentin was significantly higher than that of self-cured resin composite (p=0.017). Light activation of the bonding agents prior to applying the resin composites led to a significantly higher shear bond strength of the resin composites to dentin, compared to no light activation (p<0.05).

SUMMARY:
Fourier-Transform (FT)—Raman spectroscopy was used to evaluate in vitro the degree of conversion (DC) of Charisma dental composite cured by three different light curing units (LCUs) using soft-start and normal protocols. Eighty circular blocks of resin (7 mm in diameter x 2.5 mm thick) were prepared and cured using the following sources: halogen light (Degulux soft-start, n=20, G1-G2), low power light emitting diode (LED) with transparent polymer tip (LD13, n=20, G3-G4) and fiber optic tip (LD13, n=20, G5-G6) and, finally, high power LED (Radii, n=20, G7-G8). The top and bottom surfaces of the blocks were analyzed by FT-Raman spectroscopy. The respective DCs were estimated calculating the peak height ratio of the aliphatic C=C (1640 cm-1) and aromatic C=C (1610 cm-1) Raman modes. The DC at the surfaces ranged between 50% and 60% for the top and 46% and 58% for the bottom. The halogen light and high power LED LCUs with the soft-start and normal protocols produced the highest DC values of dental composite at both surfaces (p<0.001). Curing by low power LED in the soft-start protocol did not produce adequate DC at the depth of 2.5 mm. The type of LCU light guide tip did not present a significant statistical difference in the final DC of the dental composite (p>0.05).

SUMMARY:
This study compared the shear bond strengths of different adhesive systems to enamel and dentin of different depths. The adhesive systems used were: Single Bond one-bottle total-etch; AQ Bond one-step self-etching, Clearfil SE Bond two-step self-etching and Tyrian SPE/One-step Plus two-step self-etching.

Eighty extracted non-carious human mandibular molars were mounted in self-curing resin and the occlusal surfaces were ground with a mechanical grinder to obtain flat occlusal enamel surfaces. After applying the adhesive systems, a plastic tube was attached to the enamel surfaces. The tube was filled with a universal hybrid resin composite, which was then polymerized. The specimens were stored in water at 37°C for 24 hours. Shear bond testing was carried out using an Instron Universal testing machine with a crosshead speed of 1 mm/minute. The occlusal enamel of the 80 teeth was removed to determine the bond strengths of the adhesives to superficial dentin. To obtain deep dentin, the same teeth were ground deep towards the pulp, with the remaining dentin thickness approximately 0.7 mm. The adhesives and restorative material were then applied to the prepared dentin surfaces following the methodology described above. For occlusal enamel surfaces, the bond strength of Single Bond was significantly higher than the other adhesives. Single Bond, Clearfil SE Bond and Tyrian SPE/One-step Plus performed equally when bonded to superficial dentin; the lowest bond strength was obtained with AQ Bond. On deep dentin, the highest bond strengths were obtained with Clearfil SE Bond.

For each adhesive system, shear bond strength to enamel was statistically higher than it was to either superficial or deep dentin. There were no significant differences between shear bond strengths to superficial versus deep dentin, regardless of adhesive.

SUMMARY:
Various applications of dental lasers on dental materials have been proposed for surface modifications. This study evaluated whether laser etching could be an alternative to hydrofluoric acid (HF) etching. One hundred and ten lithia-based all-ceramic specimens (Empress 2) (R: 4 mm, h: 4 mm) were prepared and divided into five groups (n=22/group). The untreated specimens served as the control, while one of the experimental groups was treated with 9.5% HF for 30 seconds. Three remaining test groups were treated with different laser (Er:YAG laser wavelength:2940 nm, OpusDent) power settings: 300 mJ, 600 mJ and 900 mJ. Ten specimens in each group were luted to the other 10 specimens by a dual-curing cement (Variolink II), and shear-bond strength (SBS) tests were performed (Autograph, crosshead speed: 0.5 mm/minute). The results were statistically analyzed (Kruskal Wallis and Mann Whitney-U, a=.05). Mean SBS (MPa) were 31.9±4.0, 41.4±4.3, 42.8±6.2, 29.2±4.5 and 27.4±3.8 for the control and HF, 300, 600 and 900 mJ groups, respectively. SEM evaluations revealed different surface morphologies depending on the laser parameters. The differences between HF acid and 300 mJ, when compared with the control, 600 and 900 mJ groups, were significant (p<.05). The 300 mJ laser group exhibited the highest shear-bond strength values, indicating that laser etching could also be used for surface treatments.

SUMMARY:
This study evaluated the efficacy of a total-etch and three self-etch adhesives in reducing microleakage after three months water storage and thermocycling.

Thirty freshly extracted caries-free human premolars and molars were used. Class V standardized preparations were performed on the facial and lingual surfaces, with the gingival margin placed 1 mm below the CEJ. The teeth were randomly divided into four groups; Group I: Xeno III one-step self-etch adhesive (Dentsply/Caulk), Group II: Prime & Bond NT total-etch adhesive (Dentsply/Caulk), Group III: i-Bond one-step self-etch adhesive (Heraeus Kulzer) and Group IV: Clearfil SE Bond two-step self-etch adhesive (Kuraray Medical). The teeth were restored using 2 mm increments of shade A2 resin composite (Esthet-X, Dentsply/Caulk). Each layer was cured using the Spectrum 800 curing light (Dentsply/Caulk) for 20 seconds at 600mW/cm2. The teeth were stored in distilled water for 90 days. Samples were thermocycled 500x between 5°C and 55°C with a dwell time of 30 seconds, then placed in a 0.5% methylene blue dye solution for 24 hours at 37°C. Samples were sectioned longitudinally and evaluated for microleakage at the occlusal and gingival margins under a stereomicroscope at 20x magnification. Dye penetration was scored: 0=no penetration; 1=partial dye penetration along the occlusal or gingival wall; 2=dye penetration along the occlusal or gingival wall; 3=dye penetration to and along the axial wall.

A Mann-Whitney test was used to demonstrate significantly more dye penetration in Group III than in the other groups at both the occlusal and gingival scores (p<0.0001). When comparing the occlusal and gingival scores for each group, the Wilcoxon Rank test showed no significant difference in dye penetration for Xeno III (p>0.05), Prime & Bond NT (p=0.059) and I Bond (p=0.083), and Clearfil SE Bond yielded more dye penetration at the occlusal than at the gingival wall (p=0.001).

SUMMARY:
Objectives: This study: 1) analyzed the surface roughness of five novel resin composites that contain nanoparticles after polishing with three different one-step systems and 2) evaluated the effectiveness of these polishers and their possible surface damage using scanning electron microscope (SEM) analysis.

Methods: The resin composites evaluated in this study include CeramX, Filtek Supreme XT, Grandio, Premise and Tetric EvoCeram. A total of 100 discs (20/resin composites, 10x2 mm) were fabricated. Five specimens/resin composites cured under Mylar strips served as the control. The samples were polished for 30 seconds with PoGo, OptraPol and One Gloss discs at 15,000 rpm using a slow speed handpiece. The surfaces were tested for roughness (Ra) with a surface roughness tester and examined with SEM. One-way ANOVA was used for statistical analysis (p=0.05).

Results: For all the composites tested, differences between the polishing systems were found to be significant (p<0.05). For Filtek Supreme XT, Mylar and PoGo created equally smooth surfaces, while significantly rougher surfaces were obtained after OptraPol and One Gloss applications. For Grandio, Mylar and PoGo created equally smooth surfaces, while OptraPol and One Gloss produced equally rougher surfaces. Tetric EvoCeram exhibited the roughest surface with OptraPol, while no significant differences were found between Premise and Ceram X. According to SEM images, OptraPol and One Gloss scratched and plucked the particles away from the surface, while PoGo created a uniform finish, although the roughness values were not the same for each composite.

Conclusion: Effectiveness of the polishers seems to be material dependent.

SUMMARY:
The development of soft tissue air emphysema after dental treatment is not an uncommon complication. However, with scattered case reports and reviews in the dental, surgical, anesthetic, pediatric and dermatologic literature, it appears to be under-reported and, thus, seemingly as rare as suggested.1-2 To further complicate the situation, the terminology used in describing this phenomenon has not been agreed upon. Various terms have been used, such as the generic description barotraumas,3 or more specific terms, such as surgical emphysema,4-9 subcutaneous emphysema,1-2,10-18 cervicofacial emphysema19-20 and interstitial emphysema.21-22 Other terminologies that have been used are more location specific.23-26

The emphysema phenomenon related to dental treatment is usually restricted to moderate local swelling only; therefore, many cases go unrecognized or misdiagnosed. Although the majority of cases resolve spontaneously, some can lead to potentially life-threatening complications, such as airway compromise due to the accumulation of air in the retropharyngeal space, mediastinum (pneumomediastinum) and pericardium (pneumopericardium), all requiring emergency intervention.24,26-29 Migration of air to the mediastinum can cause death, arising from air embolism and soft tissue infections through the dissemination of oral flora microorganisms along the emphysematous tracts.

As the population is getting older and keeping their teeth longer, gingival recession and root caries are occurring, and the resultant Class V restoration is becoming a common procedure. Unfortunately, the incidence of emphysema also increases in older patients.30 This case presentation reports a case of air emphysema following a routine restorative dental procedure involving Class V restorations. The differential diagnosis and etiology with anatomical spaces involved are reviewed. Specific recommendations as to how to avoid such situations and the prompt recognition and management of this condition are also discussed.

SUMMARY:
The effect of interdental separation of a special separation ring and wooden wedge was investigated. In a split-mouth design, 27 patients were randomly assigned to one of two groups (W or S). In 11 patients, an interdental wooden wedge (Hawe-Neos) was placed (group W), and in 16 patients, a separation ring (Composi-Tight Gold) was placed at the contact between teeth 4/5 and 5/6. Simultaneously, in both groups, a wooden wedge, combined with a separation ring (Composi-Tight Gold), was placed on the contact between teeth 4/5 and 5/6 (reference group W+S). To measure proximal contact tightness, frictional forces were recorded at the removal of a 0.05 mm thick metal matrix band inserted between adjacent teeth. Contact tightness was measured at contacts 4 and 5 and at 5 and 6 in the third and fourth quadrant using the Tooth Pressure Meter prior to applying separation devices (T0) five minutes after application (T1) and five minutes after removal of the devices (T2).

The effect of separation was determined by calculating the differences between contact tightness before application and contact tightness with the devices in situ (T1-T0). Interdental recovery was calculated by the difference in contact tightness before application and after removal of the devices (T2-T0). To assess the presence of statistically significant differences between these measurement times, paired t-tests were applied. With each patient, either a comparison between W and W+S or S and W+S was made. For both W versus W+S and S versus W+S, paired t-tests were applied to compare differences (T1-T0 and T2-T0) between the separation devices. Within a patient, groups W and S could not be compared, therefore, to compare separation achieved between these two devices, unpaired t-tests were used.

The increase in contact tightness measured at contact 4 and 5 for group W (0.98±0.26 N) was statistically significantly less compared to the increase in group S (5.48±0.88 N) (p<0.001) or group W+S (4.62±0.68 N) (p=0.02). No significant differences were found between groups S and W+S (p=0.77). For all groups, five minutes after removal of the devices, the contact tightness at contact 4 and 5 and at contact 5 and 6 were still significantly weaker compared to the tightness at baseline (p<0.02). When separation is required for restorative procedures, such as at placement of a Class II resin composite restoration, special separation rings may be more useful than wooden wedges.

SUMMARY:
Fifty predominantly moderate or large Class II or multiple-surface Class I resin composite restorations were placed in molars under rubber dam isolation. The restorative systems used were: Alert Condensable (Jeneric/Pentron) and SureFil (Dentsply/Caulk). The restorations were classified according to size, with 7 small, 25 moderate and 18 large, of which 8 were cusp replacement restorations. Baseline, 6, 12 and 18-month double-blinded clinical evaluations were carried out using modified USPHS criteria. The independent variables: restorative material, restoration size and three other clinical factors, were tested using a Multiple Logistic Regression procedure to determine if any were predictive of failure. Of the 50 restorations, four failed by the 18-month recall, three failed due to fracture of the restoration and one due to secondary caries. Both restorative systems demonstrated a 92% success rate. No association between restoration size (p=0.99) or restorative material (p=0.65) and failure was found. Similarly, the additional variables, occlusal contact type, presence of occlusal wear facets and first or second molar, were not predictive of failure.

SUMMARY:
This study tested the effects of long-term storage and aluminum oxide air abrasion on the bond strength of self-etching adhesive systems. Extracted human third molars were ground flat with 600-grit SiC paper to expose middle coronal dentin. Clearfil SE Bond and One-Up Bond F were applied to dentin surfaces in accordance with manufacturers instructions with or without previous aluminum oxide 50 µm air abrasion. A crown was built up with the resin composite TPH Spectrum and the specimens were stored in water for 24 hours. The bonded assemblies were vertically sectioned into beams for microtensile bond testing. The beams of each tooth were individually immersed in bottles containing water at 37°C for one day, three and six months; the water was changed daily. The specimens were then subjected to microtensile bond testing. The bond strength data were subjected to ANOVA and Tukey Kramer test. Fractured specimens were analyzed in a scanning electron microscope to determine failure modes. Air abrasion improved Clearfil SE Bond bond strength in the three month evaluation. No significant difference was found between the two adhesives systems, but bond strengths gradually decreased over time. Failure modes varied significantly among groups and were influenced by long-term storage and aluminum oxide air abrasion.

SUMMARY:
This study has three main objectives: Study 1) test the reproducibility and accuracy of the ICDAS I and ICDAS II caries detection systems; Study 2) validate a new impression material (Clinpro, 3M ESPE), which is said to detect lactic acid in plaque fermenting sucrose; Study 3) devise and test a scoring system for the assessment of caries activity of coronal lesions.

Study 1): 141 extracted teeth were examined by two examiners using the ICDAS I and ICDAS II caries detection systems and validated against a histological classification system. Study 2): The accuracy of the impression material in predicting plaque with pH lower/higher than 5.5 was determined in an in situ study of 45 root dentin specimens by comparing the color change in the impression with the actual pH of the plaque, determined with a pH meter. Study 3): A scoring system to assess lesion activity was devised based on the predictive power of the visual appearance of the lesion (ICDAS II system), location of the lesion in a plaque stagnation area and, finally, the tactile feeling, rough/soft or smooth/hard, when running a perio-probe over the lesion. The accuracy was tested in a clinical study of 35 children with 225 lesions/sound surfaces and was validated using the Clinpro impression material for construct validity.

Study 1): Intra- and inter-examiner reproducibility was found to be excellent (Kappa-values >0.82) and the associations strong (Spearmans correlation coefficients >0.90). Study 2): The Clinpro impression material was found to be acceptable as compared to the results of a pH meter, the combined sensitivity and specificity was 1.63. Study 3): ROC analysis showed that the devised classification system for determining lesion activity had acceptable accuracy (area under curve = 0.84 and the highest combined sum of specificity and sensitivity was 1.67).

Thus, it is possible to predict lesion depth and assess the activity of primary coronal caries lesions accurately by using the combined knowledge obtained from visual appearance, location of the lesion and tactile sensation during probing.

SUMMARY:
In this in vitro study, quantitative confocal microscopy was used to show differences in the quantity of bacteria remaining in dentin after excavation with different methods. A further parameter was the cavity volume after excavation relative to the original lesion size. Teeth with dentin caries were divided into three groups of 20 each. The caries was removed by a single operator using a slow handpiece and a round bur. In the first group, Fluorescence Aided Caries Excavation (FACE) was carried out: violet light was used to illuminate the operating field and the operator observed the cavity through a high-pass filter and removed the orange-red fluorescing areas. The second group was excavated using Caries Detector, while the third group used conventional excavation. After excavation, cavity volume was measured; samples were stained for bacteria with ethidium bromide, and they were examined using confocal microscopy under standardized conditions. The bound stain was quantified in terms of fluorescence intensity on the confocal images. Total pixel intensity was significantly lower in the FACE Group than in the Caries Detector group (p=0.046) and in the conventional excavation group (p=0.021). Differences in cavity volume relative to original lesion size were not statistically significant (p=0.86, 0.35 and 0.51). Within the limitations of this in vitro study, it can be concluded that FACE is more effective in removing infected dentin without significantly increasing cavity size when compared to conventional excavation and excavation with the aid of caries detector dye.

SUMMARY:
This research evaluated the effect of pulp pressure on the micropermeability and sealing ability of etch & rinse and self-etching adhesives. Two etch & rinse adhesives (Prime&Bond NT and Admira Bond) and one self-etching adhesive (Xeno III) were used. Adhesive layer micropermeability was evaluated by using confocal laser scanning microscopy (CLSM). Eighteen molars were connected to a pulp pressure device and divided into two groups. One group was restored with pulp pressure and the other group without. Each group was divided into three subgroups according to the adhesive used. The adhesives were rhodamine-labeled and Class V cavities were restored. After restoration, all specimens were kept under pulp pressure conditions for 24 hours with fluorescein-labeled pulp fluid. The specimens were sectioned and the axial wall was observed under CLSM. A microleakage test was performed to evaluate the sealing. Thirty molars were divided into two groups. One group was prepared with a pulp pressure device and the other group without. Each group was divided into three subgroups as a function of the adhesive used. Class V cavities were restored and the specimens were immersed in fuchsin and sectioned. Microleakage and dentin penetration were recorded in the occlusal and gingival walls. A CLSM study showed that the etch & rinse adhesives had higher micropermeability compared to the self-etching adhesives and pulp pressure made all the adhesives more permeable. In the occlusal wall, the best sealing (hermetic) was obtained when etch & rinse adhesives were used. Xeno obtained the lowest occlusal sealing values. In the gingival wall, Xeno obtained the best sealing, followed by Admira and Prime&Bond. Pulp fluid decreased gingival wall sealing when etch & rinse adhesives were used but not when self-etching adhesive was used.

SUMMARY:
This in vitro study tested the effects of two different ceramic thicknesses, two preparation designs and two different luting agents on the marginal integrity and fracture resistance of partial ceramic crowns (PCC). Eighty extracted human molars were prepared according to the following preparation designs: a) Coverage of functional cusps/butt joint (n=40), b) Horizontal reduction of functional cusps (n=40). PCC (Vita Mark II, Cerec3 System) were fabricated and the ceramic thickness of the functional cusps was adjusted to 1): 0.5-1.0 mm and 2): 1.5-2.0 mm. PCC were adhesively luted to the cavities with either Excite/VariolinkII (VL) or RelyX Unicem (RX). The specimens were exposed to thermocycling and central mechanical loading (5000 x 5°C-55°C; 30 second/cycle; 50,0000 x 72.5N, 1.6Hz). Marginal integrity was assessed by evaluating dye penetration (fuchsine) on multiple sections in the bucco-oral direction by relating the actual penetration distance to the maximal length of the corresponding cavity wall (100%). Restoration/luting agent (RL)- and tooth/luting agent (TL) interfaces were evaluated separately. The data were statistically analyzed with the Mann Whitney U-test and the Error Rates Method (ERM), and the fracture rates were analyzed with the ?2-test. Dye penetration data indicated that ceramic thickness and luting agent had a statistically significant influence upon marginal integrity in general, irrespective of all other parameters (ERM): RX showed significantly lower microleakage along the RL interface than VL. VL revealed significantly lower microleakage at the TL interface than RX. Fifteen PCC of group 1 (0.5-1.0 mm) and two PCC of group 2 (1.5-2.0 mm) were fractured after thermocycling and central mechanical loading, with the difference being statistically significant. PCC fabricated from industrially sintered feldspathic ceramic should have at least a thickness of 1.5-2.0 mm in stress-bearing areas.

SUMMARY:
This study evaluated the importance of the union between dentin collagen and three different adhesive materials. Sixty Class V restorations were prepared on the buccal and lingual surfaces of 30 recently extracted human premolars, with the cervical margins in dentin and the occlusal margins in enamel. These restorations were distributed to three groups of 20 cavities each based on the employed adhesive system used: Group A: Single Bond; Group B: Prime&Bond NT; Group C: One Coat Bond. Each group was subdivided according to dentin treatment: 1) manufacturers’ adhesive protocol and 2) removal of the collagens fibers (total etch + sodium hypochlorite 5% for two minutes) + adhesive protocol. After the restorations were completed, the teeth were stored in saline solution (24 hours/37°C), subjected to thermal cycling, washing and scoring according to dye penetration. Dye penetration was evaluated, with the numbers ranging from 0 (no infiltration) to 3 (greatest infiltration). When the dentin microleakage scores were compared in subgroups A1XA2, B1XB2 and C1XC2, the Mann-Whitney Test revealed significant differences between groups B and C (p<5%). The better results were shown in subgroups B2 (p=0.0345) and C2 (p=0. 0029). The results showed that the collagen fibrils were not necessary for adhesion, and their removal positively influenced the marginal sealing of Prime&Bond NT and One Coat Bond.

SUMMARY:
This study determined whether it was possible to detect deformations and fractures in dental hard tissues or in composite material from internal stresses using double-exposure holographic interferometry. On the proximal side of eight intact human permanent premolars, a direct Class II cavity was prepared and restored with a self-etching adhesive (Clearfil SE Bond) and Tetric Ceram, a resin composite. In five of the specimens, Tetric Flow was used as an elastic layer. The samples were illuminated using a helium-neon laser beam, and the holograms of samples were recorded using Agfa 10E75 photographic plates. Hologram reconstructions were captured with an 8-bit monochrome CCD camera and qualitatively analyzed. Deformations and fractures appeared as fringe patterns on all interferograms, where the distribution of fringes provided location information, while the density of fringes gave the amplitude information. Greater fringe densities were observed in samples treated without a flowable composite.

SUMMARY:
This study investigated the effects of sonic and ultrasonic scaling on the surface roughness of five commonly used tooth-colored restorative materials for Class V cavities, including a flowable resin composite (Tetric Flow), a compomer (Compoglass F), a glass ionomer (Fuji II), a resin-modified glass ionomer (Fuji II LC Imp) and a resin composite (Z100). Twenty rectangular block specimens (16 x 6 x 1.5 mm) of each material were cured against matrix strips, then stored in artificial saliva for two months before performing the periodontal instrumentation. Each specimen was divided into two experimental zones, and both scaling treatments were performed on each sample. The surface roughness (Ra) of these materials was determined before and after the different instrumentations, and differences were evaluated with the use of a profilometer. Data were statistically analyzed using repeated measures of ANOVA with Tukey’s multiple comparisons and paired t-tests at a significance level of 0.05. Significant increases in surface roughness of all test materials were recorded from both scaling treatments. With the exception of Tetric Flow, ultrasonic scaling had more adverse effects on the surface roughness of all test materials compared to sonic scaling. For the test materials Z100 and Tetric Flow, resin composites showed the least surface changes in both scaling treatments, while Fuji II glass ionomer demonstrated the greatest roughness after instrumentation. More importantly, the mean surface roughness values of several materials after instrumentation were above the critical threshold roughness of 0.2 µm.

SUMMARY:
Under clinical conditions, the time needed for the proper light curing of luting composites or the multi-incremental buildup of a large restoration with halogen curing units is quite extensive. Due to the development of high power curing devices, such as argon lasers and plasma arc lights and, in order to decrease curing time, halogen and LED devices have developed a high intensity polymerization mode.

This study compared the degree of conversion using Fourier Transform Infrared Spectroscopy (FT-IR) of two composite materials: Tetric Ceram and Tetric EvoCeram polymerized with three polymerization modes (high, low and soft mode) of a Bluephase 16i LED curing unit and blue diode laser intensity of 50 mW on the output of the laser beam and 35 mW/cm2 on the resin composite sample.

Descriptive statistic, t-test, ANOVA, Pearson Correlation and Tukey Post hoc tests were used for statistical analyses. The results show a higher degree of conversion for the polymerization of composite samples with all photopolymerization modes of the LED curing unit. However, there is no significant difference in the degree of conversion between the LED unit and 50-second polymerization with the blue diode laser. Tetric EvoCeram shows a lower degree of conversion regardless of the polymerization mode (or light source) used.

SUMMARY:
This study evaluated the effect of varying thicknesses of marginal ridge on the fracture resistance of endodontically-treated maxillary premolars restored with composite.

Ninety non-carious maxillary premolars, extracted for orthodontic reasons, were selected for this experimental in vitro study. The teeth were randomly assigned to six groups (n=15). Group 1 received no preparation. In groups 2 through 6, the premolars were root filled and DO preparations were created, while MOD preparations were also created for group 2. The condition of the boxes was: the gingival seat was 1.5 mm above the CEJ and the buccolingual dimensions were 3.5 mm in gingival and 3 mm in occlusal. In groups 3 through 6, the dimensions of the mesial marginal ridge were measured using a digital caliper as follows: 2 mm, 1.5 mm, 1 mm and 0.5 mm, respectively. All samples in groups 2 through 6 were restored with a dentin bonding system (DBS: Single Bond, 3M) and resin composite (Z 250, 3M). Subsequently, premolars from all six groups were subjected to a thermocycling regimen of 500 cycles between 5°C and 55°C water baths. Dwell time was 30 seconds, with a 10-second transfer time between baths.

The premolars were submitted to axial compression up to failure at a 45° angle to the palatal cusp in Universal Test Equipment (Tinius Olsen, Ltd, H5K-S model).

The mean load necessary to fracture the samples was recorded in newtons (N), and data were subjected to analysis of variance (ANOVA) and LSD post-hoc test.

According to these results, the mean loads necessary to fracture the samples in each group were (in N): group 1: 732 ± 239, group 2: 489 ± 149, group 3: 723 ± 147, group 4: 696 ± 118, group 5: 654 ± 183 and group 6: 506 ± 192).

Differences between group 1 and groups 2 and 6, and also differences between groups 3, 4 and 5 compared with group 2 and 6 were statistically significant (p<0.05).

SUMMARY:
A laboratory study was performed to assess the influence of beveling the margins of cavities and the effects on marginal adaptation of the application of ultrasound during setting and initial light curing.

After minimal access cavities had been prepared with an 80 µm diamond bur, 80 box-only Class II cavities were prepared mesially and distally in 40 extracted human molars using four different oscillating diamond coated instruments: A) a U-shaped PCS insert as the non-beveled control (EMS), B) Bevelshape (Intensiv), C) SonicSys (KaVo) and D) SuperPrep (KaVo). In groups B–D, the time taken for additional bevel finishing was measured. The cavities were filled with a hybrid composite material in three increments. Ultrasound was also applied to one cavity per tooth before and during initial light curing (10 seconds). The specimens were subjected to thermomechanical stress in a computer-controlled masticator device. Marginal quality was assessed by scanning electron microscopy and the results were compared statistically.

The additional time required for finishing was B > D > C (p=0.05). In all groups, thermomechanical loading resulted in a decrease in marginal quality. Beveling resulted in higher values for “continuous” margins compared with that of the unbeveled controls. The latter showed better marginal quality at the axial walls when ultrasound was used.

Beveling seems essential for good marginal adaptation but requires more preparation time. The use of ultrasonic vibrations may improve the marginal quality of unbeveled fillings and warrants further investigation.

SUMMARY:
Purpose: This investigation evaluated the effect of glass and polyethylene fiber inserts on the microleakage of Class II composite restorations with gingival margins on root surfaces. Methods: Fifty-four intact molars were sterilized with Gamma irradiation and mounted in acrylic bases. Class II slot cavities were made on both proximal sides of each tooth (3 mm wide, 1.5 mm deep) with the gingival margin on the root surface. The teeth were divided into nine groups, according to the technique of restoration and type of bonding agent. Filtek P-60 (3M/ESPE) was used to restore all cavities. Two types of fiber inserts were used: glass fiber (Ever Stick, StickTech) and polyethylene (Ribbond-THM), with three bonding agents being employed: Scotch Bond Multipurpose (3M/ESPE), Clearfil SE Bond (Kuraray) and Xeno IV (Dentsply). In the experimental groups, 3 mm long fiber inserts were inserted into restorations at the gingival seat. The control groups had no fiber inserts. The restorations were made incrementally and cured with LED light (UltraLume5, Ultradent). The restored teeth were stored in water for two weeks, then thermocycled for 3,000 cycles (5°C and 55°C). The tooth surfaces were sealed with nail polish, except at the restoration margins. The teeth were immersed in 2% procion red dye solution, sectioned and dye penetration was assessed to determine the extent of microleakage according to a six-point scale. Results: The fiber groups generally showed reduced microleakage scores compared to the control groups. The Clearfil SE Bond (Kuraray)/Filtek P-60 (3M/ESPE) combination produced the lowest degree of microleakage, irrespective of fiber type. However, the glass fiber groups were more consistent in reducing microleakage than the polyethylene groups. Conclusions: The use of fiber inserts significantly reduced gingival microleakage in Class II composite restorations with gingival margins in dentin, irrespective of the adhesive used. Clearfil SE Bond (Kuraray)/Filtek P60 (3M/ESPE) produced the lowest microleakage scores.

INTRODUCTION:
Dental treatment modalities for patients suffering from anorexia nervosa vary, depending on the severity of erosion of the dentition caused by induced vomiting. However, it is important for dentists to cooperate with physicians to obtain details of the psychiatric and somatic conditions of patients. The mental health of patients should be taken into consideration. A restorative approach, which aims to preserve the natural tooth structure, whenever possible, should be the paramount concern. However, partial or complete coverage of indirect restorations may have to be used in cases with extensive loss of tooth structure and vertical dimension. This report deals with a patient who showed severe erosion associated with gastroesophageal reflux caused by anorexia nervosa. The patient needed extensive restorative treatments, including ceramic laminate veneers and partial coverage metallic crowns.

SUMMARY:
This study evaluated the two-year clinical performance of one microhybrid composite and three different types of flowable resin materials in non-carious cervical lesions. A total of 252 non-carious cervical lesions were restored in 37 patients (12 male, 25 female) with Admira Flow, Dyract Flow, Filtek Flow and Filtek Z250, according to manufacturers' instructions. All the restorations were placed by one operator, and two other examiners evaluated the restorations clinically within one week after placement and after 6, 12, 18 and 24 months, using modified USPHS criteria. At the end of 24 months, 172 restorations were evaluated in 26 patients, with a recall rate of 68%. Statistical analysis was completed using the Pearson Chi-square and Fisher-Freeman-Halton tests (p<0.05). Additionally, survival rates were analyzed with the Kaplan-Meier estimator and the Log-Rank test (p<0.05). The Log-Rank test indicated statistically significant differences between the survival rates of Dyract Flow/Admira Flow and Dyract Flow/Filtek Z250 (p<0.05). While there was a statistically significant difference between Dyract Flow and the other materials for color match at 12 and 18 months, no significant difference was observed among all of the materials tested at 24 months. Significant differences were revealed between Filtek Z250 and the other materials for marginal adaptation at 18 and 24 months (p<0.05). With respect to marginal discoloration, secondary caries, surface texture and anatomic form, no significant differences were found between the resin materials (p>0.05). It was concluded that different types of resin materials demonstrated acceptable clinical performance in non-carious cervical lesions, except for the retention rates of the Dyract Flow restorations.

SUMMARY:
This in vivo pilot study evaluated eight products with hydrogen peroxide (HP) concentrations ranging from 15% to 35%. The treatment contact time varied from 15 minutes to 60 minutes. Patients were evaluated for color at baseline, immediately after treatment and at one, two, four and six weeks after treatment using a colorimeter, shade guide and photos.

All eight products were effective in bleaching teeth. Colorimeter data for DE immediately after treatment was 6.77. At one and six weeks after bleaching, there were 51% and 65% reductions in DE, respectively.

SUMMARY:
This study evaluated the effect of cycling various pH demineralizing solutions on the surface hardness, fluoride release and surface properties of restorative materials (Ketac-Fil Plus, Vitremer, Fuji II LC, Freedom and Fluorofil). Thirty specimens of each material were made and the surface hardness measured. The specimens were randomized into five groups according to the pH (4.3; 4.6; 5.0; 5.5 and 6.2) of the demineralizing solution. The specimens were submitted to pH-cycling for 15 days. The specimens remained in the demineralizing solution for six hours and in the remineralizing solution for 18 hours. Then, the surface hardness (SH) was remeasured and the surface properties were assessed. Fluoride release was determined daily. Data from SH and the percentage of alteration in surface hardness were analyzed by analysis of variance (p<0.05); the Kruskal-Wallis test was performed for the fluoride release results. When hardness was compared, the variation in pH led to a positive correlation for glass ionomer cements and a negative correlation for fluoride release. For polyacid-modified resin composites, a negative correlation was found with regards to fluoride release; no significant correlation was observed for hardness. Surface properties were influenced: an acidic pH led to a greater alteration, except for polyacid-modified resin composites. The pH of the demineralizing solution influenced fluoride release from the tested materials. The pH variation altered hardness and surface properties of glass ionomer cements but did not influence polyacid-modified resin composites.

SUMMARY:
There are several incremental techniques for the placement of posterior composites in Class II cavities that were introduced to overcome clinical failures associated with these restorations. This study evaluated microleakage in Class II cavities restored with four different curing techniques.

On 40 non-carious, freshly extracted human premolars, Class II cavities were prepared following a standard pattern in which the mesial cavities had a cervical margin 1.0 mm above the CEJ, and for distal cavities, 1.0 mm below the CEJ. The specimens were randomly divided into four groups. Each cavity surface was conditioned with 35% phosphoric acid and rinsed to remove the excess water, followed by a dental bonding agent (PQ1) being used for all the cavities. The teeth were then restored with a fiber reinforced resin-based composite (Neulite F), using four different techniques: Group 1, metal matrix with wooden wedge; Group 2, transparent matrix with reflective wedge; Group 3, metal matrix with wooden wedge and light tip and Group 4, metal matrix with wooden wedge and bio-glass cylinder. Then, the restorations were finished and polished, rebonded, thermocycled (2000 times, 5°C to 55°C, 30 second dwell time), stained, sectioned vertically and viewed under a stereomicroscope (40x). They were then scored on a 0-4 scale based on microleakage at the gingival margins. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. The results showed that Group 1 demonstrated the most leakage, while the other three groups showed less leakage than Group 1. There was no significant difference between the enamel and dentin gingival margin groups. As a result of these findings, the authors concluded that restoration with metal matrices, using light conducting instruments, results in significantly less microleakage at the gingival margins of Class II resin composite restorations.

SUMMARY:
Objective: This study compared the initial and one year shear bond strengths (SBS) of resin composite bonded to amalgam using Amalgambond-Plus. Methods: Resin composite cylinders (Point 4, Kerr Corporation) were bonded to either etched-enamel (A), 50% etched enamel-50% polished amalgam (B), airborne-particle abraded amalgam (C), carbide bur prepared amalgam (D) and airborne-particle abraded 50% amalgam-50% etched-enamel (E). Shear bond strengths were determined using a standardized testing device (Ultradent Products) in a universal testing machine (Instron model 4204). The failed interfaces were evaluated with SEM to obtain visual evidence of the failure mode. Results: ANOVA indicated significant differences among the groups (p<0.0001). SBS in MPa (Mean/SD) were for A at year 0: (24.63/4.19), A at year 1: (16.84/7.25), B at year 0: (9.13/2.18), B at year 1: (15.54/6.41), C at year 0: (16.82/3.60), C at year 1: (15.26/3.90), D at year 0: (9.27/4.03), D at year 1: (7.97/7.17), E at year 0: (16.67/4.87) and E at year 1: (8.63/3.64). Conclusion: In vitro testing demonstrated that resin composite masking has the strongest, most durable SBS on airborne-particle abraded amalgam and airborne-particle abraded enamel-amalgam surfaces and could be used as a method to improve the esthetics of amalgam restorations.

SUMMARY:
This study assessed the surface quality of four nanoparticle composites and one hybrid composite after polishing with three different techniques. Nanocomposites Premise (KerrHawe), Tetric EvoCeram (Ivoclar Vivadent), Filtek Supreme (3M ESPE) and Ceram X Duo (Dentsply) and the hybrid composite Herculite XRV (KerrHawe) were selected. Sixty specimens 7x7 mm each were fabricated from these materials. After light curing, the specimens were treated with 600 grit sandpaper discs. Fifteen specimens of each composite were polished using flexible Sof-Lex discs (3M ESPE). The remaining 45 specimens of each material were prepared with three finishing protocols: a single 30 µm diamond (n=15), a sequence of a 30 µm and a 20 µm diamond (n=15) and a 30 µm diamond followed by a tungsten carbide finishing bur (n=15). Each series of 15 specimens was then subdivided into three groups of five and polished with the Astropol system (Ivoclar Vivadent), OptiShine brushes (KerrHawe) and the Enhance/PoGo system (Dentsply). Quantitative evaluation of surface roughness was done with the help of optical laser stylus profilometry. Average roughness (Ra) was calculated, and the effect of the materials, the finishing regimen and the polishing methods on surface roughness were analyzed by three-way and two-way Anova and Scheffé post-hoc tests. Qualitative evaluation of the surfaces was done with the help of scanning electron microscopy (PSEM 500, Phlipps). Photomicrographs were assessed with respect to surface quality in four gradings.

Surface roughness after polishing was significantly influenced by three factors: composite material (p<0.001), finishing protocol (p<0.001) and polishing method (p<0.001). There were strong interactions between the finishing and polishing methods (p<0.001). Two of the nanocomposites were significantly smoother (p=0.001), while the other two had a surface quality similar to that of a hybrid composite. Astropol achieved the lowest average roughness on all composites. Except for a combination of a 30 µm diamond and OptiShine brushes, which caused severe roughness, all the polishing methods produced surfaces that were significantly smoother than using the Sof-Lex discs.

SUMMARY:
This study analyzed the influence of C-factor, flexural modulus and viscous flow on gap formation in resin composite restorations. Two resin composites, a mini-filled hybrid (P 60) and a nanofilled (Supreme), were used. The flexural modulus was obtained from bar-shaped specimens submitted to three-point bending. Viscous flow was obtained from the difference between the initial and final diameter of resin composite disks submitted to a load of 10 N for 120 seconds. Gap analysis was conducted in three types of cylindrical cavities (C-factor of 1.8, 2.6 and 3.4) that were prepared on the occlusal surfaces of human molars. The gap width at the dentin-resin composite interface was measured using a 3D scanning system (Talyscan 150). The data were analyzed by ANOVA and Student-Newman-Keuls' test, t-test and linear regression analysis (a=0.05). The cavities with C-factor 3.4 presented the highest Gap formation (p<0.0001). The lowest Gap formation was found in cavities restored with Supreme resin composite (p<0.0001). P 60 presented significantly higher flexural modulus and lower viscous flow than Supreme (p<0.0001). Regression analyses detected a significant influence of flexural modulus and viscous flow on gap formation (p<0.05).

SUMMARY:
This study investigated the composite-to-composite microtensile bond strength and inter-facial quality after using different combinations of intermediate agents and pre-curing temperatures of repairing resin. Forty-five composite discs (8x4mm) of Gradia Direct Anterior (GC Corp), stored in a saline solution at 37°C for one month, were sandblasted (50 µm aluminum oxide), cleaned (35% phosphoric acid) and randomly divided into three groups (n=15) according to the intermediate agent applied: 1) no treatment; 2) unfilled resin (Scotchbond Multi-Purpose Adhesive, 3M ESPE); 3) flowable composite (Gradia LoFlo, GC Corp). Each disc was incrementally repaired (8x8 mm) with the same resin as the substrate. For each group, three subgroups (n=5) were created, depending on the pre-curing temperature of the repairing resin-4°C, 23°C or 37°C. Two bonded specimens per group were prepared to evaluate the composite-to-composite interfacial quality via scanning electron microscope. Microtensile bond strength measurements were performed with the remaining three specimens and failure mode was examined by stereomicroscopy. Two-way ANOVA revealed that temperature (p<0.001), intermediate agent (p<0.001) and the interaction (p=0.002) significantly affected the repair strength. Post-hoc comparisons revealed that bond strengths were significantly lower using a 4°C repairing resin in groups where intermediate agents were used. The highest bond strengths were recorded when flowable composite was used as an intermediate agent under each of the three temperature conditions. Interfacial quality improved by raising the resin temperature from 4°C to 37°C.

SUMMARY:
Purpose: This study evaluated the effect of thermocycling on the microtensile bond strength of four adhesive luting agents to GN-I CAD-CAM ceramic. The hypothesis tested was that thermocycling did not affect bonding effectiveness, irrespective of the luting agents used.

Materials and methods: Ceramic specimens of two different sizes (6x8x3 mm; 13x8x4 mm) were fabricated from GN-I CAD-CAM ceramic blocks (GC) using a low-speed diamond saw. Two different sized porcelain discs were bonded with one of the four composite luting agents (Linkmax [LM], Panavia [PN], RelyX Unicem [UN] and Variolink II [VL]) according to the manufacturer's instructions. The specimens were stored for 24 hours in distilled water at 37°C and subjected to 0; 10,000; 20,000 and 40,000 thermocycles prior to µTBS testing. Two-way analysis of variance was used to test the influence of luting cement, thermocycling and interaction between both (p<0.05). The Tukey HSD test determined statistical differences in µTBS for each luting composite between the different thermocycling conditions (p<0.05). The mode of failure was determined at a magnification of 50x using a stereomicroscope (Wild M5A).

Results: Two-way ANOVA revealed that microtensile bond strength was affected by the luting cement, thermocycling and a combination of both. No difference in bond strength between Linkmax, Panavia F and Variolink II was noticed after 24 hours of water storage (LM: 47.6 MPa; PN: 41 MPa; VL: 36 MPa). RelyX Unicem scored significantly lower than Linkmax and Panavia F (UN: 24.2 MPa). The influence of thermocycling on bond strength was different for the four luting cements. Using Variolink II, the bond strength remained stable after 40,000 thermocycles (43.6 MPa). Linkmax showed a significant decrease in bond strength after 10,000 (26 MPa) and 40,000 thermocycles (14.8 MPa). Panavia F and RelyX Unicem were the most negatively influenced, as all specimens failed prior to testing (pre-testing failures) when the specimens were thermocycled 10,000 and 20,000 times or longer, respectively.

Regarding the failure mode, there was a correlation between bond strength and type of failure. Initially, a combination of adhesive and mixed adhesive-cohesive failures was noticed. The percentage of adhesive failures increased, together with a decrease in bond strength.

Conclusion: It was concluded that there were significant differences among the four resin composite cements in terms of their bonding effectiveness to CAD-CAM ceramic after thermocycling. The varying degrees of bonding effectiveness of these adhesive luting agents highlight the need for material specifications.

SUMMARY:
This study compared the effects of moisture and rubbing action on the immediate and one-year microtensile bond strength (BS) of an ethanol/water-based adhesive system (Single Bond [SB]) and an acetone-based system (One Step [OS]) to dentin. A flat superficial dentin surface on 60 human molars was exposed by wet abrasion. Two coats of the adhesives were applied on either a dry (D) or rewetted surface (W) with no (NRA), slight (SRA) or vigorous rubbing action (VRA). After light curing (600mW/cm2/10 seconds), composite buildups were constructed incrementally and the specimens were stored in water (37°C/24 hours). They were longitudinally sectioned in the "x" and "y" directions to obtain bonded sticks (0.8 mm2) to be tested in tension at 0.5 mm/minute. The sticks from each tooth were then divided, stored in water at 37°C and tested immediately and after 12 months (12M) at 0.5 mm/minute. The bond strength values of sticks from the same hemi-tooth were averaged for statistical purposes. The prematurely debonded specimens were included in the hemi-tooth mean. The data from each adhesive was analyzed by three-way ANOVA and Tukey's multiple comparison tests (a=0.05). In the dry groups, high bond strength values were obtained under VRA. When the dentin was kept moist, both SRA and VRA provided high resin-dentin bond strength values. Reductions in bond strength values after one year of water storage were not observed for the SB adhesive or were less pronounced for the OS adhesive when it was vigorously rubbed onto the dentin surface.

SUMMARY:
Objectives: This study evaluated the antibacterial potential of four different adhesive systems. Methods & Materials: Gluma Comfort Bond + Desensitizer, Gluma Comfort Bond, iBond and One-Up Bond F were tested against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus and Actinomyces viscosus. The inhibition of growth by calibrated preparations was quantified by the measurement of zones of inhibition on bacterial lawns. Bactericidal activity was determined as reductions in recoverable colony-forming units in bacterial suspensions exposed to test preparations. Results: All the preparations exhibited detectable zones of inhibition for all target bacteria through six months. When the bactericidal action was evaluated, all the materials were able to kill all the tested bacteria when tested immediately after polymerization. After one week of aging, iBond was the only material that continued to kill all of the test strains.

SUMMARY:
The effectiveness of four paint-on tooth whiteners was evaluated and compared in this in vitro study. Sixty extracted anterior teeth were selected and randomly assigned to five groups: 1-(AS) Artificial Saliva (Roxane); 2-(MSW) Sparkling White (Meijer); 3-(CNE) Crest Night Effects (Procter & Gamble); 4-(ABB) Beautifully Bright (Avon) and 5-(CSWN) Simply White Night Gel (Colgate-Palmolive). The teeth were cleaned with a soft bristle toothbrush and toothpaste (Procter & Gamble) to remove any residue from the storage solution. The bleaching gels were painted onto the surface of the teeth, and they were then wrapped in gauze moistened with artificial saliva and kept in 100% humidity at 98°F in a laboratory oven (Precision Scientific model 18EG) for 24 hours. The treatment was repeated once a day for 14 days. Visual color assessment was done using a value-oriented Vitapan Classical Shade Guide (Vident) and a colorimeter (Minolta Chroma Meter CR 321). PVS jigs (Exaflex, GC America) were fabricated for each tooth. Visual and colorimetric readings were recorded at baseline, 7 and 14 days. One-way ANOVA and Tukey multiple comparisons test were used to assess differences between groups. CNE and CSWN presented the highest mean number of shade changes and ?E*ab Colorimeter readings. ABB and MSW did not significantly lighten the teeth, as measured by either method of evaluation after two weeks of the bleaching regimen.