Chronological List of Articles

SUMMARY:
It is well established that saliva is an important factor for the health of both soft and hard tissues in the oral cavity. This study determined: 1) the correlation between unstimulated salivary flow assessed using the Modified Schirmer tear strip Test (MST), with gravimetric and volumetric measurements and 2) the MST value that would allow the most reliable identification of patients with severe (<0.1 ml/minute) and moderate (<0.2 ml/minute) hyposalivation. A retrospective clinical study was conducted using data from 90 patients seen at the Indiana University School of Dentistry. All patients had a sample of unstimulated whole saliva collected by drooling for five minutes for volumetric/gravimetric assessment, followed by placement of the Schirmer strip in the floor of the mouth for three minutes (MST). Results showed a non-linear association between the MST and volumetric/gravimetric methods, with moderate Spearman correlation coefficients (0.67-0.71). Analysis of ROC-curves suggests that a cutoff screening value of 25 mm/three minutes provides high sensitivity (77%) and positive predictive value (71%) without significantly affecting specificity (80%). In conclusion, this study supports use of the MST test as a screening tool for hyposalivation.

SUMMARY:
Prospective clinical studies comparing the results of different types of restorations of endodontically treated teeth are lacking. This study compared the clinical success rate of endodontically treated premolars restored with fiber posts and direct composite to the restorations of premolars using amalgam.

Premolars with Class II carious lesions were selected and randomly assigned to one of two experimental groups: (1) restoration with amalgam or (2) restoration with fiber posts and composite. One hundred and nine teeth were included in Group 1 and 110 in Group 2.

Patients were recalled after 1, 3 and 5 years.

No statistically significant difference was found between the proportion of failed teeth in the two experimental groups. Significant differences were observed between the proportion of root fractures (p=0.029) and caries (p=0.047), with more root fractures and less caries observed in the teeth restored with amalgam at the five-year recall. Within the limits of this study, it can be concluded that restorations with fiber posts and composite were found to be more effective than amalgam in preventing root fractures but less effective in preventing secondary caries.

SUMMARY:
Objective: To investigate variation in performance measures of fibre-optic, high-speed air-turbine handpieces during the course of daily use in general dental practice.

Materials and Methods: Four groups of five new high-speed fibre-optic handpieces were used in the routine treatment of patients over a period of 30 months by four general dental practitioners in two dental practices: Groups A, B: Super-Torque Lux 3 650B (KaVo, Biberach, Germany); Group C: BORA 898LE (BienAir SA, Bienne, Switzerland) and Group D: Toplight (W&H Dentalwerk, Burmoos, Austria). The dental practice teams had been rehearsed in the procedures to be followed before starting the study. Each dentist used the handpieces in strict rotation, while the groups were rotated monthly between practitioners. Four performance characteristics were measured before use, then at regular intervals: free-running speed (Hz) and bearing resistance (µNm) were measured using a purpose-built testing machine (Darvell-Dyson); illuminance (lux) and sound pressure level (dB(A)) were also measured. Handpieces were cleaned and lubricated in accordance with manufacturers’ directions; all were autoclaved wet at 134°C for three minutes.

Results: Free-running speed showed an initial increase after use for Groups A, B and C, which may be associated with a decrease in bearing resistance. All handpieces in Group C suffered bearing failure between months 21 and 23, preceded by a substantial increase in noise, while those in Group D suffered failure of the fibre-optic system between months 18 and 24. Other deterioration due to use was identified but Groups A, B and D were still in use at month 30.

Conclusions: Variation in free-running speed, bearing resistance, illuminance and sound pressure level can be used effectively to monitor changes in air-turbine handpieces due to normal use. Although an increase in bearing resistance is associated with decreasing free-running speed, noise appears to be a useful indicator of imminent bearing failure. Assiduous adherence to manufacturers’ directions for cleaning and lubrication may have contributed to increased bearing life.

SUMMARY:
The measurement of performance characteristics of dental air turbine handpieces is of interest with respect to product comparisons, standards specifications and monitoring of bearing longevity in clinical service. Previously, however, bulky and expensive laboratory equipment was required. A portable test machine is described for determining three key characteristics of dental air-turbine handpieces: free-running speed, stall torque and bearing resistance. It relies on a special circuit design for performing a hardware integration of a force signal with respect to rotational position, independent of the rate at which the turbine is allowed to turn during both stall torque and bearing resistance measurements. Free-running speed without the introduction of any imbalance can be readily monitored. From the essential linear relationship between torque and speed, dynamic torque and, hence, power, can then be calculated. In order for these measurements to be performed routinely with the necessary precision of location on the test stage, a detailed procedure for ensuring proper gripping of the handpiece is described. The machine may be used to verify performance claims, standard compliance checks should this be established as appropriate, monitor deterioration with time and usage in the clinical environment and for laboratory investigation of design development.

SUMMARY:
This in vitro study evaluated gingival wall microleakage in packable and microhybrid conventional composite restorations with and without a flowable composite liner. Each group was evaluated with gingival margins situated in both enamel and cementum/dentin.

Two hundred and forty Class II cavities were prepared in extracted third molars, half with gingival margins in enamel and half with margins in dentin/cementum. In groups of 30, restoration was undertaken with packable alone (3M Filtek P60), conventional alone (3M Z250), packable plus flowable liner (3M Filtek Flow) and conventional plus flowable liner. All used 37% phosphoric acid etch and Scotchbond 1 (3M) as the bonding system. After restoration, the teeth were thermocycled (between 5°C, 37°C and 60°C) 1,500 times, soaked in 0.1% methylene blue, sectioned and microleakage from the gingival margin scored. Statistical analysis was performed using Kruskal Wallis and Mann-Whitney U tests.

There was no significant difference between systems in terms of leakage scores when gingival margins were situated in enamel (p=0.70). All restorations with margins in cementum/dentin leaked significantly more than those with margins in enamel (p<0.001). There was no significant difference between leakage scores of 3M Z250 and Filtek P60 with cementum/dentin gingival margins (p=0.68). Use of a flowable composite liner (3M Filtek Flow) against cementum/dentin was associated with increased microleakage (p<0.001).

In this study, leakage scores suggest that gingival margins should be placed in enamel. The conventional and packable resin composites tested were not associated with differences in microleakage. Leakage data do not support the use of flowable resin composite linings in Class II resin composite restorations.

SUMMARY:
Self-etch adhesives try to solve difficulties commonly associated with the clinical application of etch-and-rinse adhesives. Their application procedure is considered less time-consuming and, more importantly, less technique-sensitive. The main objective of this study was to determine the bonding effectiveness to and the interaction with enamel/dentin of three contemporary one- and two-step self-etch adhesives by microtensile bond strength testing (µTBS), Fe-SEM and TEM when compared to a control two-step self-etch and a three-step etch-and-rinse adhesive. The one-step self-etch adhesive, Adper Prompt (3M ESPE), scored the lowest µTBS of all experimental and control adhesives tested. Conversely, the two-step self-etch adhesives Clearfil SE (Kuraray) and OptiBond Solo Plus Self-Etch (Kerr) approached the values obtained by the three-step etch-and-rinse control (OptiBond FL, Kerr) when bonded to enamel and dentin. Ultra-morphological characterization showed that interfacial morphology and the pH of the self-etch primer/adhesive are strongly associated. The interaction with dentin varied from the formation of a submicron, hydroxyapatite-containing hybrid layer for the “mild” self-etch adhesive Clearfil SE to a 3-5 µm thick, hydroxyapatite-depleted hybrid layer for the “strong” self-etch adhesive Adper Prompt. The two-step self-etch adhesives AdheSE and OptiBond Solo Plus Self-Etch presented with a hybrid layer with a hydroxyapatite-depleted top part and a hydroxyapatite-containing base part and were therefore classified into a new group of self-etch adhesives, namely “intermediary strong” self-etch adhesives.

SUMMARY:
This study evaluated the influence of dentin adhesive application technique (pre-curing vs non pre-curing) on microtensile bond strength (µTBS) to dentin and adhesive layer thickness in indirect resin restorations. Seven proprietary dentin adhesives were tested, including one-step and multi-step products. Experimental groups included adhesive pre-cure (PC) with a halogen light source and no pre-cure (NPC) prior to resin cement insertion.

Thirty caries-free molars received an MO inlay preparation. Inlays made with Tetric Ceram resin composite were cemented using a dual-cured resin luting agent. Prior to inlay cementation, each tooth was treated with one dentin bonding agent, using pre-cure (PC) or no pre-cure (NPC). After storage in distilled water at 37°C for 24 hours, the teeth were sectioned along their long axis to produce serial sticks for microtensile bond strength testing at 0.5 mm/minute. The results were subjected to statistical analysis by one-way and two-way analysis of variance (ANOVA) and Tukey’s multiple comparison test (p ≤ 0.05). For the film thickness evaluation, 10 additional teeth were restored and sectioned mesiodistally. The thickness of the adhesive layer was evaluated by SEM at 1000x magnification at the pre-selected locations.

The µTBS varied from 11.7 ± 4.5 MPa to 43.4 ± 9.8 MPa. The effect of pre-curing the adhesive was material specific. No adhesive layer was visualized for the adhesives used without the pre-curing step. The thickness of the adhesive layer for the pre-cured groups varied according to the different areas analyzed.

SUMMARY:
This study evaluated the efficiency of a new E/F-speed film, Insight, at the determination of approximal carious lesion depths compared with Ultraspeed. Radiographs of 80 extracted human molars and premolars were taken with both films under standardized conditions. The presence or absence of caries and depth of lesions was determined by three observers using a predetermined scale. The actual status of each surface was determined histologically. Observer responses were assessed with the Gamma measure of association test. Differences between the observers’ agreement levels were not significant.

The efficiency of Insight and Ultraspeed at true depth diagnosis was found to be 54.9%; 55.8% and Gamma values were found to be 0.883 and 0.922, respectively, at p<0.001. The difference between the two films was not statistically significant (p=0.852). This study suggested that there was no statistically significant difference between the two films at detecting the depths of approximal carious lesions.

SUMMARY:
This study compared the shear bond strengths (SBS) to dentin achieved with six self-etching systems and one total-etch one-bottle adhesive system. Seventy freshly extracted bovine incisors were mounted in acrylic molds and the facial surfaces ground to expose middle dentin, which was polished by 600-grit sand paper. The incisors were randomly assigned to groups (n=10): Adper Prompt Self-Etch Adhesive, 3M-ESPE (ADP) and One-Up Bond F, Tokuyama (OU) as self-etching adhesives; AdheSE, Ivoclar-Vivadent (ADH), Clearfil SE Bond, Kuraray (SE), Optibond Solo Plus–Self-Etch, Kerr (OP) as self-etching primers, Tyrian SPE, BISCO (TY) as a self-priming etchant and Single Bond, 3M-ESPE (SB), a total-etch one-bottle adhesive served as a control. All adhesives were applied according to the manufacturers’ instructions with the respective hybrid composites. The specimens were thermocycled for 500 cycles (5°C to 55°C), then loaded to failure in an Instron Universal Testing Machine at a crosshead speed of 0.5 mm/minute. Mean bond strengths were analyzed with one-way ANOVA, followed by a Duncan’s post hoc test. SBS (mean ±SD) were: ADH = 13.2 (±5.3)b; ADP = 6.8 (±4.4)c; OP = 18.2 (±3.8)a; OU = 3.5 (±1.5)c; SB = 12.2 (±4.2)b; SE = 12.4 (±4.0)b; TY = 5.5 (±1.4)c. Superscript letters indicate Duncan’s homogeneous subsets. The self-etching adhesives OU and ADP and the self-priming etchant TY resulted in lower dentin SBS. OP resulted in the highest mean dentin SBS, while the other materials tested in this study (SE and ADH) presented similar dentin SBS to a total-etch one-bottle bonding system (SB).

SUMMARY:
The clinical performance of light curing resin composites is greatly influenced by the quality of the light-curing unit (LCU). Halogen LCUs are commonly used for curing composite materials. However, they have some drawbacks. The development of new, blue, super bright light emitting diodes (LED LCU) of 470-nm wavelength with high light irradiance comes as an alternative to standard halogen LCUs of 450-470-nm wavelengths.

This study evaluated the surface hardness of the different resin-based composites (flowable, hybrid and packable resin composites) cured by LED LCU or halogen LCU. A Teflon mold 10-mm in diameter and 2-mm in depth was made to obtain five disk-shaped specimens for each experimental group. Then, the specimens were cured by an LED LCU or halogen LCU for 40 seconds. The hardness of the upper and lower surfaces was measured with a Barcoll hardness-measuring instrument. The statistical analysis was performed using one-way analysis of variance (ANOVA) and Duncan test at a p=0.05 significance level.

The results of the hardness test indicated that the hardness of resin composites cured by an LED LCU were greater than those cured by a halogen LCU. Additionally, for all resin-based composites, the hardness values for the upper surfaces were higher than the lower surfaces. However, for both results no statistically significant differences were observed (p>0.05).

SUMMARY:
Dental hand instruments are not efficient in removing all infected dentin when performing carious removal for minimal intervention techniques. The use of an antibacterial dentin conditioner may therefore be useful when restoring cavities that have residual carious dentin. Antibacterial agents—chlorhexidine hydrochloride, cetylpyridinium chloride, cetrimide, benzalkonium chloride and sodium hypochlorite, were added either to a dentin conditioner used for glass ionomer cements or distilled water at 1% concentration. Dentin conditioning solutions at pH 2.5, 4.9 and 7.7 were also prepared, along with 1% aqueous thymol. Using an agar diffusion test, 25 µl aliquots were examined for their inhibitory effects on three cariogenic bacteria. After 24 hours, an agar pellet was extracted adjacent to the agar well and placed on a second inoculated agar plate to observe sustained inhibitory effects, after which this procedure was repeated one more time. Antibacterial dentin conditioners showed significant inhibitory effect compared to the control over the three test periods (p<0.016). The combination of dentin conditioners with antibacterial agents significantly reduced the inhibitory effect compared to the antibacterial aqueous solutions (p<0.016). One-percent aqueous thymol showed no inhibitory effect against the test bacteria. The cetrimide-dentin conditioner showed the greatest inhibitory effect against all three test bacteria over the three experimental periods (p<0.016). The inhibitory effect of antibacterial agents was significantly reduced when combined with a dentin conditioner. Only the cetrimide-dentin conditioner combination produced significant inhibitory effects against all three test organisms.

SUMMARY:
This in vitro study aimed to design a method for the objective evaluation of carious dentin using numerical values. This study also investigated the relationship between the color of carious dentin stained with a caries detector dye using this objective method and the rate of bacterial detection as detected by a polymerase chain reaction (PCR). In 15 molars with occlusal dentin caries and three extracted sound molars, dentin was removed in multiple steps with 300 µm removed each step. Before and after every removal, images of a color-matching sticker and carious surfaces stained with a caries detector dye were acquired simultaneously using a CCD camera and dentinal tissue samples were removed with a round bur. Next, corrected L*, a* and b* values of the carious surfaces (CIE 1976 L*a*b* color system) were calculated from the color changes of the stickers in the images. In addition, bacterial DNA in the dentinal tissue was detected by PCR. From evaluations of the receiver operating characteristic curves for the L*, a* and b* values, the L* value was determined to be a more useful parameter than a* or b* for detecting bacterial infection using the caries detector dye. The bacterial detection rates of carious dentin decreased as the L* values of carious dentin stained with the dye increased. When the L* values were more than 60, the dentin had no bacterial infection. This study clarified the relationship between the colors of lesions stained with a caries detector dye and the rates of bacterial detection.

SUMMARY:
This study aimed to evaluate the microtensile bond strength (µTBS) of photo- and dual-cure adhesives to sound and caries-affected dentin using total- and self-etch techniques. Human third molars with occlusal caries were prepared as previously described by Nakajima and others (1995). Dentin surfaces were bonded with Optibond Solo Plus (Kerr; photo-cure adhesive) or Optibond Solo Plus + Dual-cure activator (Kerr; dual-cure adhesive) with total- and self-etch technique. Clearfil AP-X (Kuraray) was used for composite buildups. Following storage in distilled water at 37°C for 24 hours, the teeth were sectioned into 0.7-mm thick slices to obtain sound and caries-affected dentin slabs, then trimmed to form hour glass shapes with a 1 mm2 cross-sectional area. The specimens were subjected to microtensile testing using EZ-test (Shimadzu) at 1 mm/minute. Data were analyzed using three-way ANOVA and Student’s t-Test (p<0.05). Bond strengths to sound dentin with photo- and dual-cure adhesives using total- and self-etch techniques were significantly higher than those to caries-affected dentin. Dual-cure adhesive significantly decreased bond strengths both to sound and caries-affected dentin. The total-etch technique showed no beneficial effect on caries-affected dentin compared with the self-etch technique. Scanning electron microscopic observation of the resin-dentin interfaces revealed that hybrid layers in caries-affected dentin were thicker than those observed in sound dentin with photo- and dual-cure adhesives. Resin infiltration into dentinal tubules of caries-affected dentin was hampered by the presence of mineral deposits.

SUMMARY:
This study investigated the effect of various hygiene maintenance procedures on the surface finish of minifill (Filtek A110 [AO], 3M-ESPE), flowable (Filtek Flow [FF], 3M-ESPE) and polyacid-modified (F2000 [FT], 3M-ESPE) composites. Procedures included pumice-water slurry with rotating brush (PB), pumice-water slurry with rotating rubber cup (PC), prophylaxis paste with rubber cup (ZC), prophylaxis gel with rubber cup (GC) and air-powder polishing (AP). Specimens not exposed to these procedures were used as the control group. For each material, 48 specimens (3-mm long x 3-mm wide x 2-mm deep) were made and stored in distilled water at 37°C for one month. The specimens were then treated with 1200 grit sandpaper using a lapping device, stored for an additional two months in distilled water at 37°C and randomly divided into six groups (n=8). The mean surface roughness (Ra, µm) of the specimens after exposure to the various hygiene procedures was determined using a surface profilometer. Data was subjected to ANOVA/Scheffe’s test at significance level 0.05. Mean Ra values ranged from 0.09 to 2.17, 0.06 to 1.38 and 0.38 to 1.25 for AO, FF and FT, respectively. The effect of hygiene procedures on surface roughness was material dependent. Among the various procedures, the smoothest surface was observed after treatment with prophylaxis gel and the roughest with air-powder polishing. For all materials, the use of pumice-water slurry with brush also caused significant roughening. Composite restorations may require re-polishing after exposure to some hygiene maintenance procedures, as Ra values exceeded the critical threshold surface roughness for bacterial adhesion (0.2 µm).

SUMMARY:
The smear layer, which occurs during cavity preparation procedures, does not constitute a stable substructure in the bond of restorative material to dental hard tissues. Depending on the dissolution of this material in the course of time, microleakage occurs between the tooth and restorative material.

This study evaluated the effects of different conditioner agents (Fuji Cavity Conditioner, 10% maleic acid, 35% phosphoric acid and 3% hydrogen peroxide) on Fuji IX microleakage, Fuji IX-enamel and Fuji IX-dentin combination in Class I cavities prepared to standards having the dimensions of 4x3x2 mm3 in extracted primary molars. The restorations were then subjected to thermocycling procedures and soaked in the 0.5% basic-fuchsin dye for 24 hours. Some sections were taken, parallel to the long axis of the tooth in a mesio-distal direction, and evaluated under a stereomicroscope for leakage. Also, two samples of Fuji IX-enamel and dentin combinations were chosen randomly from each group for evaluation in scanning electron microscopy (SEM).

The distribution of microleakage occurred as follows: Control Group > Hydrogen Peroxide > 10% Maleic acid > Fuji Cavity Conditioner = Phosphoric acid. The difference between microleakage scores obtained from the groups was statistically significant (p<0.05). The SEM evaluation revealed a close interface connection in all groups except for the control and hydrogen peroxide groups in the Fuji IX-enamel combination. In the Fuji IX-dentin combination, however, a close interface connection was observed except in the control group.

In conclusion, the application of conditioner agents to Class I cavities restored with glass ionomer cement with a high viscosity in vitro either diminishes or completely eliminates microleakage.

SUMMARY:
This study evaluated microleakage at the composite-repair interface after using different methods of surface treatment. Eighty resin composite specimens (Filtek Z250, 3M Dental Products) aged in artificial saliva for three months were divided into four groups (n=20) according to the following surface treatment methods: untreated control–no roughening or abrasion of the surface; roughening with diamond burs; jet prophylaxis with sodium bicarbonate particles and air abrasion with 50 µm aluminum oxide particles. Each method was examined using scanning electron microscopy (SEM) to evaluate changes in surface topography. All groups were then etched with 37% phosphoric acid, coated with a bonding agent (Single Bond, 3M Dental Products) and received new resin applications. The samples were then thermocycled (800 cycles/5°C to 55°C [±2]) and immersed in 2% methylene blue buffered dye solution (7.0 pH) for four hours. Three examiners measured the extent of microleakage in a stereoscope microscope using four representative scores. For all experimental groups, no significant difference in repair microleakage was identified by the Kruskal-Wallis test (p>0.05). Therefore, different testing methods of surface treatment showed the same effect on dye penetration along the repair interface.

SUMMARY:
This study measured the linear polymerization displacement and polymerization forces induced by polymerization shrinkage of a series of flowable resin-based restorative materials.

The materials tested were 22 flowable resin-based restorative materials (Admira Flow, Aelite Flow, Aeliteflow LV, Aria, Crystal Essence, Definite Flow, Dyract Flow, Filtek Flow, FloRestore, Flow-it, Flow-Line, Freedom, Glacier, OmegaFlo, PermaFlo, Photo SC, Revolution 2, Star Flow, Synergy Flow, Tetric Flow, Ultraseal XT and Wave). Measurements for linear polymerization displacement and polymerization forces were performed using custom made measuring devices. Polymerization of the test materials was carried out for 60 seconds by means of a light curing unit, and each property was measured for 180 seconds from the start of curing in eight specimens for each material. Statistical evaluation of the data was performed with one-way analysis of variance (ANOVA), Tukey’s Studentized Range (HSD) test (p=0.05) and simple linear regression.

A wide range of values was recorded for linear polymerization displacement (26.61 to 80.74 microns) and polymerization forces (3.23 to 7.48 kilograms). Statistically significant differences among materials were found for both properties studied. Very few materials (Freedom, Glacier, and Photo SC) presented low values of linear polymerization displacement and polymerization forces (similar to hybrid resin composites), while the majority of materials presented very high values in both properties studied. Study of the shrinkage kinetics revealed the exponential growth process of both properties. The polymerization forces development exhibited a few seconds delay over linear polymerization displacement. Simple linear regression showed that the two polymerization shrinkage properties that were studied were not highly correlated (r2=0.59).

SUMMARY:
The objective of this study was to determine the influence of dietary solvents on the shear punch strength of nanofill (Filtek Supreme [FS], 3M-ESPE) and ormocer (Admira [AM], Voco) composites. The strength of these materials was also compared to a minifill composite (Z250 [ZT], 3M-ESPE), a compomer (F2000 [FT], 3M-ESPE) and a highly viscous glass ionomer cement (Ketac Molar Quick [KM], 3M-ESPE). Thirty-two specimens (8.7 mm diameter and 1-mm thick) of each material were made, randomly divided into four groups of eight and conditioned for one week as follows–Group 1 (control): distilled water at 37°C; Group 2: 0.02M citric acid at 37°C; Group 3: 50% ethanol-water solution at 37°C and Group 4: heptane at 37°C. After conditioning, the specimens were restrained with a torque of 2.5 Nm and subjected to shear punch strength testing using a 2-mm diameter punch at a crosshead speed of 0.5 mm/minute. The shear punch strength of the specimens was computed and data subjected to ANOVA/Scheffe’s tests at significance level 0.05. With the exception of AM, the strength of all materials was not significantly influenced by dietary solvents. For AM, conditioning in heptane resulted in significantly higher shear strength values. The strength of the nanofill and ormocer composites was lower than the minifill composite but higher than the compomer and highly viscous glass ionomer cement investigated.

SUMMARY:
This study evaluated the effects of four polishing methods on the occlusal surfaces of direct Class II composite restorations under clinical conditions.

Forty premolars and 40 molars were treated with direct Class II restorations using the hybrid composite Herculite XRV (Kerr). After placement of the restorations, all of which were on occlusal surfaces, they were finished with a sequence of 30 µm diamonds and tungsten carbide instruments. Twenty restorations each, consisting of 10 premolars and 10 molars, were polished with one of the four following methods: (1) Diafix-oral (Mueller-Dental), (2) MPS gel (Premier), (3) P 403-W (Dentsply) and (4) Occlubrush (KerrHawe). Selection of the polishing methods followed a randomized protocol. Replicas of the restored teeth were fabricated and the occlusal surfaces were evaluated quantitatively for roughness with the help of profilometry. Qualitative assessment of the surfaces by SEM was done with respect to roundness of contours and surface roughness. The results were analyzed statisti-cally by two-way ANOVA, chi-squared test for crosstables and Kruskal-Wallis test.

Analysis of the quantitative data showed that there was no significant effect of the polishing methods on occlusal surface roughness (p>0.05). Localization of the restoration in premolars or molars had no effect on surface roughness (p>0.05). With respect to occlusal relief, SEM examination revealed that the use of the Occlubrush resulted in significantly more edged contours compared to the other polishing methods (p=0.008). Qualitative roughness evaluation showed that there were no significant differences among the four polishing methods (p>0.05).

SUMMARY:
Purpose: This study evaluated the response of human pulps capped with a bonding agent after bleeding control with different hemostatic agents. Material and Methods: Twenty-five Class II cavities were prepared in 25 caries-free human premolars scheduled for extraction due to orthodontic treatment. The pulp exposures were performed on the occlusal floor. The teeth were randomly divided into five groups. Groups 1-4 were capped with an adhesive system after hemostasis with different agents: Group 1—saline solution; 2—ferric sulfate; 3—2.5% NaOCl; 4—Ca(OH)2 solution. In Group 5, after hemostasis with saline solution, the pulp was capped with calcium hydroxide (control group). Then, ScotchBond Multi Purpose Plus was applied and the resin composite Z-100 placed incrementally according to the manufacturers’ directions. After 60 days, the teeth were extracted and processed for light microscopic examination (HE) and the groups were categorized in a histological score system. The data were subjected to a non-parametric test (a=0.05). Results: Overall, the histological features showed that the pulp response from Groups 1 through 4 was inferior to the response from Group 5, where dentin bridging occurred. In all groups, where the adhesive system was used for capping, the pulp response varied from an acute inflammatory, with varying degrees, to necrosis. No dentin bridge was formed after adhesive capping.

SUMMARY:
This clinical study compared the efficacy of three different bleaching techniques with respect to the bleaching times required in order to achieve six grades of whitening in human teeth. Any side effects that were noted and the patients’ acceptance of the method were recorded by a visual analog scale ranging from 0 to 10. Moreover, epoxy casts from the study teeth were analyzed by scanning electron microscopy in order to detect any potential changes in the enamel surface due to treatments.

SUMMARY:
This study compared the degree of marginal leakage of a compomer in Class V cavities of human primary molars prepared by a conventional dental bur and air abrasion with or without acid etching.

Fifty-six non-carious extracted primary molars were randomly divided into four groups (n=14) to be prepared by four techniques: Group-1: Bur followed by acid etching: Class V cavity preparations were placed on the buccal surfaces of each tooth using a high-speed handpiece. The preparations were 1.5-mm deep, 3-mm long and 2-mm wide, with the occlusal margin in enamel and the cervical margin extending 0.5 mm below the cementoenamel junction. The preparations were acid etched with 37% phosphoric acid starting at the enamel margins for 30 seconds and rinsed with water for 20 seconds. The preparations were then restored with Compoglass F. 2-Group 2: Bur: The preparations and the treatment procedures were the same as in Group 1, with the exception of 37% phosphoric acid application. Group 3: Air abrasion followed by acid etching: Class V cavity preparations were placed on the buccal surfaces of each tooth using a handpiece of an air-abrasive system (PrepStart, Danville Engineering). The system was supplied with dry compressed air at 80 psi. In all tests, the air-abrasion system was operated with an 80˚-angle handpiece tip and 50-mm aluminum oxide particles. A tip with a 0.38-mm inner diameter was used at a 2-mm distance. The treatment procedures were the same as in Groups 1 and 2. Group 4: Air abrasion: The preparations and treatment procedures were the same as in Group 3, with the exception of 37% phosphoric acid. After finishing the restorations, the teeth were stored in distilled water at 37˚C for 24 hours. The samples were thermocycled for 500 cycles between 5˚C and 55˚C with a dwell time of 30 seconds. The samples were then immersed in 0.5 percent basic fuchsin dye for 24 hours at 37˚C. The surface-adhered dye was then rinsed in tap water and the teeth were embedded in a chemically-activated acrylic resin and bisected longitudinally in a mesiodistal direction with a low speed diamond disk. Each section was examined under a stereomicroscope (Nikon, Tokyo, Japan) at 20x magnification. The data were analyzed statistically by Kruskal-Wallis analysis of variance to determine any statistical significant differences in microleakage scores among the groups at a p-value of 0.05. Also, the enamel versus cementum-dentin microleakage scores of each group were compared using z-test at the 0.05 significance level. There was no statistically significant difference among the groups (p>0.05), but a statistical difference between enamel and cementum-dentin surfaces was evaluated (p<0.05).

SUMMARY:
This study investigated, mechanically and morphologically, whether the dentin surface irradi-ated by CO2 laser could be a possible adherent when bonded with simplified-step adhesives. Buccal enamel and cementum of extracted human premolars were removed to expose a flat dentin surface. The dentin surfaces were irradiated continuously with CO2 laser at 1.0 W. Before bonding with either a single-bottle adhesive (Single Bond) or a self-etching priming system (Mega Bond), the irradiated dentin surface was treated as follows: no treatment, NaHCO3 powder abrasion and wet-grinding with 600-grit SiC paper. The treated dentin surfaces were bonded to resin composite with either of the two adhesives. Non-irradiated dentin surfaces were also used as control. Resin bonded specimens were stored in water at 37°C for 24 hours and subjected to microtensile bond test. Additionally, to observe the resin/irradiated dentin interface, resin-bonded specimens were similarly prepared, sectioned into slabs, embedded in epoxy resin, polished with diamond pastes, sputter coated Au-Pd and examined with scanning electron microscopy (SEM). After SEM observation, the specimens were further polished with diamond paste to remove the Au-Pd sputter-coat, immersed in HCL and NaOCl and finally observed by SEM again.

In the presence of carbonized dentin, microtensile bond strength drastically decreased but recovered to the control value by removing the carbonized dentin layer visually with SiC paper for both adhesive systems. However, the laser-affected dentin that remained on the bonded interface was easily dissolved with NaOCl and HCl.

SUMMARY:
This study investigated the surface roughness of conventional (Fuji II Capsulated [FC], GC Corporation, Tokyo, Japan), resin-modified (Fuji II LC [FL], GC Corporation) [FL] and highly viscous (Fuji IX GP Fast [FN], GC Corporation) glass ionomer cements [GICs] after exposure to five prophylaxis regimes. The surface roughness obtained was compared to untreated polished specimens (control). The prophylaxis regimes evaluated were rotating brush with pumice-water slurry [PB]; rotating rubber cup with pumice-water slurry [PC]; rotating rubber cup with prophylaxis paste [PP]; rotating rubber cup with prophylaxis gel [PG] and air-powder polishing [PJ]. Forty-eight specimens (3-mm long x 3-mm wide x 2-mm deep) were made for each material. The specimens were stored in distilled water at 37°C for one month, polished with 1200 grit sandpaper using a lapping device and randomly divided into six groups (n=8). They were then stored for an additional two months in distilled water at 37°C prior to exposure to the various prophylaxis regimens. The mean surface roughness value (Ra; µm) was measured with a profilometer. Data was subjected to ANOVA/Scheffe’s tests at significance level 0.05. Mean Ra ranged from 0.30 to 1.70 µm for FC, 0.40 to 2.52 µm for FL and 0.36 to 1.79 µm for FN. Regardless of the type of glass ionomer, treatment with PJ resulted in significantly rougher surfaces when compared to the control group. For FC and FN, a significant increase in roughness was observed after treatment with PB and PP, respectively. Glass ionomer restorations may require re-polishing after exposure to some prophylaxis regimens.

SUMMARY:
The degree of conversion of resin-based luting agents used for retention of prefabricated posts has been questioned due to the difficulty of light penetration into the resin-filled root canal. This study evaluated the depth of cure of a resin-modified glass ionomer cement (Rely X–3M ESPE) and two resin-based luting agents (Rely X ARC—3M ESPE and Enforce–Dentsply). Twenty-four 14x2x2mm3 specimens were prepared in a Teflon split mold with the three luting agents (n=8). After preparation, the specimens were stored at 37°C in a dark box for 24 hours prior to microhardness testing. Measurements of Knoop hardness were performed at three different depths: superficial, medium and deep thirds. The results (KHN) were statistically analyzed by repeated measures ANOVA and Tukey test (0.05), which showed that resin-based luting agents presented the highest Knoop hardness values within the superficial third. Within the medium third, there were no significant differences among luting materials. However, within the deep third, Rely X presented the highest values. KHN values of resin-based luting agents decreased remarkably as depth increased.

SUMMARY:
This study compared the efficiency of unaided visual examination, intraoral camera and operating microscope according to a visual scoring system (ERK) at occlusal caries detection.

A total of 84 extracted human molars were mounted to create mouth models with a premolar in contact on both sides. The models were examined in a phantom head simulating clinical conditions by four observers using the three techniques: unaided visual examination, an intraoral camera and on operating microscope according to the ERK scale. The teeth were than sectioned in a mesio-distal direction and examined under a stereomicroscope with 10x magnification for histological validation.

The sensitivity, specificity, positive predictive and negative predictive values were calculated for the four observers with three techniques and statistical analyses were performed using Friedman and DUNN tests, while strength of agreement was determined by calculating Kappa values.

From the data, mean sensitivity values were calculated as 0.26, 0.43, 0.49 and mean specificity values as 0.87, 0.80 and 0.73 for unaided visual examination, intraoral camera and operating microscope, respectively. The Kappa values ranged between 0.187 and 0.301 for visual examination, 0.328 and 0.459 for intraoral camera and 0.363 and 0.516 for operating microscope.

As a result, the use of an intraoral camera and operating microscope improved occlusal caries detection according to the ERK scale.

SUMMARY:
The microtensile bond strength of resin com-posite bonded to human enamel was evaluated utilizing four light-cure bonding agents. Human third molars were embedded in auto-cure acrylic and the buccal surfaces were sequentially abraded to 400 grit. Resin composite cylinders were then bonded using the four bonding systems according to the manufacturer’s specifications. Each bonded tooth produced three to four longitudinal sections which were then laterally notched to give a square bond area (~2.25 mm2). Specimens (n=10) were assigned to two groups: Group I was stored in distilled water at 37° ± 2°C for seven days. Group II was stored in distilled water at 37° ± 2°C for seven days, during which time it was thermocycled in hot and cold water baths for 1,000 cycles. In addition, a water sorption test was performed on three of the four adhesive systems. The microtensile bond strength of the conventional adhesive Optibond Solo Plus was significantly greater than that of the self-etching adhesives Tyrian SPE and Prompt L-Pop. Adhesive systems that were more hydrophilic tended to show lower bond strengths, especially after thermocycling.

SUMMARY:
This in vitro study morphologically evaluated the effect of some current surface pre-treatments on dentin, using scanning electron microscopy, and related these morphological alterations to clinical implications. The labial surfaces of 30 bovine lower incisors were ground to obtain a flat dentin \surface and were finished with 600-grit SiC paper to produce standardized smear layers. The teeth were randomly divided into six groups of five each. Group 1 was the control group, smear layer covered dentin; Group 2 was etched with 37% phosphoric acid (PA) for 15 seconds; Group 3, 37% PA for 15 seconds, followed by 10% NaOCl for 60 seconds; Group 4, 10% NaOCl for 60 seconds; Group 5, a self-etching primer (Clearfil SE Bond, CSEB-primer) was applied for 20 seconds; Group 6, CSEB-primer for 20 seconds, followed by NaOCl for 60 seconds. The specimens were fixed, dehydrated, dried and analyzed by SEM. Treatment with 37% PA removed the smear layer, funneled the tubules and resulted in a collagen-rich surface which appeared to have collapsed in its outermost part, producing a dense surface layer covered with silica particles. When 37% PA treatment was followed by 10% NaOCl, the col-lagen network was removed to reveal an eroded, rough mineral surface with numerous lateral branches and larger than normal tubular orifices. The action of 10% NaOCl on the smear layer-covered dentin showed no significant alteration in surface morphology. The treatment with CSEB-primer dissolved the smear layer but only partially dissolved the smear plugs. The tubules did not present the typical funnel shape seen following PA treatment. These morphological aspects on dentin surface must influence bonding results. The dentin surface alterations produced by PA appeared to be a very severe demineralization pattern, quite irregular and less permeable to monomer infiltration, while the surface provided by the self-etching primer appeared to be a more uniform, less porous surface, and the association with simultaneous monomer infiltration may reduce the occurrence of mistakes in clinical bonding procedures.

SUMMARY:
This study assessed the influence of different beverages on the microhardness and surface roughness of microfilled (A110, 3M/ESPE), hybrid (Z250 3M/ESPE) and flowable (Flow, 3M/ESPE) resin composites, over time. Twenty-four disc-shaped specimens (10 mm; 2-mm thick) of each resin composite were fabricated, thereby forming three groups (n=24). Knoop microhardness and surface roughness (Ra) were analyzed at predetermined evaluation periods: 24 hours, and 7, 30 and 60 days after specimens fabrication. The 24-hour measurements were recorded after storage in artificial saliva. Next, each group (n=24) was divided into four subgroups (n=6) according to the test beverages: Coca-Cola, sugar cane spirit, coffee and artificial saliva (control). Control specimens were kept in saliva throughout the experiment (60 days). For experimental specimens, a 60-day testing cycle was carried out: specimens were initially stored in saliva for four hours, then submitted to a five-minute immersion in the beverages (Coca-Cola, sugar cane spirit, coffee) intercalated by immersions in saliva three times daily. Microhardness/roughness measurements were done at 7-, 30- and 60-day intervals. Data were submitted to three-way ANOVA and Scheffée test (p<0.05). It was observed that the tested beverages somewhat altered (p<0.05) the composites’ microhardness and/or surface roughness. Knoop microhardness—for all resin composites, microhardness remained stable up to the 30-day record, decreasing significantly at the 60-day evaluation. During the interaction beverage X evaluation period, it was observed that the microhardness of materials immersed in coffee and Coca-Cola remained stable up to the seven-day measurement, showing a decrease at the 30-day record and a more accentuated drop at the 60-day evaluation (p<0.05). Specimens immersed in sugar cane spirit exhibited no significant change in microhardness up to the seven-day measurement, increasing significantly at the 30-day record and later decreasing at the 60-day evaluation. Surface Roughness—For all resin composites, surface roughness increased at the seven-day measurement, while decreasing at the 30-day record and even more at the 60-day record. In the interaction beverage X evaluation period, the surface roughness of specimens immersed in test beverages increased at the seven-day measurement, showing a gradual decrease at the following records (30- and 60-day evaluations). The findings of the reported research disclosed that all beverages altered, to some degree, the microhardness and/or surface roughness of the tested resin composites. The alterations’ effects ranged from slightly adverse to a markedly negative impact on the composites’ microhardness and surface roughness, depending on the characteristics of the materials, type of beverage and the evaluated period. Generally, the greater number of immersions in beverages resulted in a more accentuated impact on the resins’ properties.

SUMMARY:
Clinical studies have shown that endodontically treated teeth restored with short posts or deficient ferrules show a high failure risk. This study evaluated the influence of fatigue loading on the quality of the cement layer between prefabricated quartz coated carbon fiber posts with restricted length and the root canal wall in maxillary premolars. Two adhesive resin composite cements, chemical-cured Panavia 21 (Group 1) and dual-cured RelyX-ARC (Group 2), and one resin-modified glass-ionomer cement, chemical-cured RelyX (Group 3), ∆ were selected for this study. Post-and-core restorations were made on single-rooted human maxillary premolars from which the coronal sections were removed at the level of the proximal cemento-enamel junction (CEJ). Following endodontic treatment, a post-and-core restoration with 6-mm post length was prepared for each tooth. The posts were directly cemented into the root canal and, after applying an adhesive (Clearfil Photo Bond), they were built up with a core build-up composite (Clearfil Photo Core). For each group (n=8), half of the specimens were exposed to fatigue loading (106 load cycles) almost perpendicular to the axial axis (85°), while the other half were used as the control. Three parallel, transverse root sections, 1.5-mm thick, were cut from each specimen at the apical, medial and coronal location. These sections were examined by Scanning Electron Microscopy (SEM) to evaluate the integrity of the cement layer, while the retention strength of the cemented post sections was determined with the push-out test. The multivariate results of MANOVA showed that the condition main effect (fatigue or control) was not significant (p=0.059); the two other main effects, type of cement and section location, were significant (p=0.001 and p=0.008). For both the push-out strength and SEM evaluation of the cement layer integrity, the results significantly improved from RelyX to RelyX-ARC to Panavia 21 and also from apical to coronal.

SUMMARY:
Purpose: The objective of this study was to evaluate the tensile bond strength (BS) and microleakage (MI) of bonded amalgam restorations to dentin when an unfilled and a filled system are used under three application modes. Material and Methods: Seventy-two and 96 human molars, respectively, were employed for BS and MI tests. For BS, the occlusal surface of the molars was ground flat until dentin exposure. A 3-mm area was delimited for bonding. For MI, Class V cavities were prepared in the CEJ (4 mm x 4 mm x 2 mm). For each test, the molars were randomly divided into six treatment groups defined by a combination of the levels: Adhesive system (Scotchbond Multi-Purpose Plus [SBMP], Optibond dual cure [OPTB]) and Application mode (light–LC, chemical–C and combination of light and chemical curing–LCC). After adhesive application, the amalgam was condensed into a Teflon mold (BS) and into the cavities (MI). After storage in saline solution for seven days at 37°C, the specimens were subjected to the BS test at 0.5 mm/minute. For microleakage evaluation, the restorations were sealed with nail varnish, except for an area 1 mm around the restoration, immersed in 5% methylene blue solution for 24 hours and sectioned into two halves. Each half was evaluated by two trained examiners at 25x magnification in a 0-3 score system and the highest score was recorded. The BS data was evaluated by two-way ANOVA and Tukey’s test (a=0.05). The MI data were analyzed by Kruskal Wallis and Mann-Whitney tests (a= 0.05). Results: The main factors were significant for the BS test: the highest BS mean was obtained using the LCC technique and the OPTB system. Regarding the MI test, only the application mode was significant: lower dye infiltration was observed for LC and LCC.

SUMMARY:
This study evaluated the microleakage of resin-modified glass ionomer, flowable compomer and flowable resin composite restorations on a Class V cavity of simulated advanced root caries under a flexural load cycling condition. Thirty-six non-carious human maxillary premolars were mounted in cylindrical acrylic resin molds. The cavities were prepared in the proximal root surface, from the middle of the buccal surface to the middle of the lingual surface, approximately 1 mm below the cemento-enamel junction, 2 mm axial width and 1.2 mm in depth. The teeth were randomly assigned to one of three groups with 12 teeth in each group: Group 1: Cavity conditioner and Fuji II LC (GC America), Group 2: Prime & Bond NT and Dyract Flow (Caulk-Dentsply), Group 3: Excite and Tetric flow (Ivoclar/Vivadent). Specimens were settled laterally on a fatigue- testing machine that was adjusted to deliver a force of 60N. The specimens were load cycled at 1Hz for 5000 cycles, placed in a staining solution and sectioned to evaluate microleakage penetration. Results indicate that the coronal and gingival margins showed significant microleakage differences among the three restorations (p<0.05). At the coronal margin, there was no significant difference between Groups 2 and 3. At the gin-gival margin, there was no significant difference between Groups 1 and 2. It was concluded that the marginal sealing ability of a flowable resin composite under a flexural cycling load was better than in other selected materials and that flowable resin composite with dentin adhesive was a desirable alternative for root caries restorations extended to the proximal surface.

SUMMARY:
This study evaluated the flexural strength, flexural modulus, modulus of resilience and water sorption of eight flowable light-cured restorative materials compared with two conventional restoratives (as control). Forty specimens of each material were made. Twenty specimens were immediately flexural tested, while the remaining 20 were weight-measured and immersed in distilled water in a 37°C incubator. After 24 hours, the samples were weight-measured again to identify water sorption and they were flexural tested. The findings were statistically analyzed using t-test, one-way ANOVA, Tukey test and Pearson’s Product-Moment Correlation. The results of the flexural strength test were also analyzed using Weibull statistic. All flowable light-cured restorative materials except Palfique Estelite Low Flow exhibited immediate flexural strength values between the conventional ones. All flowable light-cured restorative materials showed 24-hour flexural strength values between the conventional ones. The Weibull modulus for immediate flexural strength of the materials varied from 6.37 to 15.23, while for 24-hour flexural strength, the strength varied from 8.10 to 14.30. In both conditions, all flowable light-cured resin composites showed lower flexural moduli but higher modulus of resilience than the conventional ones. The water sorption of all resin composites was lower than the flowable light-cured compomer. There was a distinct relation (r=-0.84, p<0.01) between the increasing ratio in modulus of resilience and the amount of water sorption.

SUMMARY:
The influence of water disinfectants used in dental unit waterlines on the dentin bonding of different adhesive systems was investigated by using push-out tests. Three hundred and twenty dentin disc specimens were prepared from caries-free human molars. In each specimen, a standardized conical cavity was prepared while cooling with water from a dental unit containing one of three different disinfectants (n=80 each group; A=control: water without disinfectant, B: Alpron neutral, C: Alpron mint, D: Dentosept P). Subsequent rinsing of the cavities was performed with the respective disinfectant. The cavities were filled with the following combinations of dentin adhesives and composites, resulting in 16 subgroups (n=20): Syntac Classic/Tetric Ceram, Clearfil Liner Bond 2V/Luxacore, OptiBond FL/Prodigy and Prime&Bond NT/Spectrum. After polishing the fillings, one half of each subgroup (n=10) was stored in water (37°C) for 24 hours. The other half was stored in water (37°C) for 180 days and additionally thermocycled (2000 cycles at 5/55°C). The bond strength was then measured by push-out tests. Statistical analysis of the data was carried out using ANOVA and pairwise t-tests (Significance level p≤0.01). The disinfectants showed no significant influence on the loads required for debonding of Syntac Classic/Tetric Ceram, Clearfil Liner Bond 2V/Luxacore and OptiBond FL/Prodigy as compared to the controls. However, the use of disinfectants in the water supply of a dental unit decreased dentin bond strength in the specimens filled with Prime&Bond NT/Spectrum.

Disinfectants in the water of dental unit waterlines may have an influence on dentin bonding, depending on the adhesive system used.

SUMMARY:
The purpose of this study was to compare the thermal emission and curing efficiency of LED (LEDemetron 1, SDS/Kerr) and QTH (VIP, BISCO) curing lights at maximum output and similar power, power density and energy density using the same light guide. Also, another LED curing light (Allegro, Den-Mat) and the QTH light at reduced power density were tested for comparison. Increase in temperature from the tips of the light guides was measured at 0 and 5 mm in air (23°C) using a temperature probe (Fluke Corp). Pulpal temperature increase was measured using a digital thermometer (Omega Co) and a K-type thermocouple placed on the central pulpal roof of human molars with a Class I occlusal preparation. Measurements were made over 90 seconds with an initial light activation of 40 seconds. To test curing efficiency, resin composites (Z100, A110, 3M/ESPE) were placed in a 2-mm deep and 8-mm wide plastic mold and cured with the LED and QTH curing lights at 1- and 5-mm curing distances. Knoop Hardness Numbers (KHN) were determined on the top and bottom surfaces (Leco). Bottom hardness values were expressed as a percentage of maximum top hardness. No significant differences were found in maximum thermal emission or KHN ratios between the LED (LEDemetron 1) and the QTH (VIP) at maximum output and similar energy densities (ANOVA/Tukey’s; a=0.05).

SUMMARY:
This in vitro study evaluated whether the treatment of human enamel with whitening agents containing different concentrations of carbamide or hydrogen peroxide changes the susceptibility of enamel to caries. Twenty-four sound human incisors were selected for this study. For each tooth, the crown was sectioned into two halves in the cervical-incisal direction. One half of the sectioned tooth was treated and the other half was used as a control specimen. Each half was randomly divided into three treatment groups (eight two-halves/group). The whitening agents were 10% carbamide peroxide, 20% carbamide peroxide with fluoride and 35% hydrogen peroxide. Following pretreatment, the specimens were demineralized for four days in an in vitro microbial caries model and then analyzed using a confocal laser scanning microscope (CLSM). Results showed that there were no significant differences between the treated and controlled specimens for teeth treated with 10% carbamide peroxide or 35% hydrogen peroxide. However, specimens treated with 20% carbamide peroxide with FP (0.11% fluoride and potassium nitrate) were less susceptible to caries than their controls at p≤ 0.05. In conclusion, application of bleaching agents does not increase the caries susceptibility of human enamel.

SUMMARY:
The purpose of this study was to evaluate the placement of two restorative materials, including a compomer (F2000, 3M ESPE) and a resin composite (Silux Plus, 3M ESPE), in non-carious cervical lesions using a self-etching bonding agent (F2000 self-etching primer/adhesive) and a fifth generation bonding agent (Single Bond, 3M ESPE) and to evaluate and compare these restorations for marginal discoloration, secondary caries, anatomical form, retention, surface texture and marginal adaptation at baseline and annually for three years. F2000 and Silux Plus were used to restore the teeth with moderate-sized non-carious cervical lesions. F2000 was placed using two different bonding agents: F2000 self-etching primer/adhesive (F2000SE group) and Single Bond (F2000SB group); Silux Plus was placed as a control using Single Bond (SiluxSB group). Thirty restorations of each material/dentin adhesive combination were placed. All restorations were evaluated at baseline and annually for three years using a modified USPHS scale. At the end of the three-year recall, Silux Plus had significantly better surface texture than F2000 (p<0.0001). In addition, marginal adaptation significantly worsened over time starting at one year, as compared with baseline, for all groups (p<0.0001). When anatomic form was compared between F2000 and Silux Plus, the p-value was 0.085, demonstrating that F2000 was slightly better than Silux Plus.

Likewise, when comparing marginal adaptation between the F2000SE and SiluxSB groups, the p-value was 0.064, demonstrating that F2000 with the self-etching primer had better margins than Silux Plus with Single Bond. No other differences were found among the groups.

SUMMARY:
This study evaluated the two-year clinical performance of two types of giomers (Beautifil, a surface reaction giomer and Reactmer, a full-reaction giomer), in occlusal (Class I) and cervical (Class V) cavities using the USPHS criteria. Forty-two cervical erosion and carious lesions were restored using Beautifil and Reactmer following manufacturer’s instructions. Twenty occlusal cavities were restored with Beautifil. Fifteen patients (mean age 35, ranging in age from 20 to 50 years) participated in the study. The success rate for cervical Beautifil restorations after two years was 80%, while the success rate for cervical Reactmer restorations was 71%. Occlusal Beautifil restorations had a 100% success rate.

SUMMARY:
This study evaluated the clinical performance of a posterior resin composite used with a fourth- and fifth-generation bonding agent. Sixty-two Class I and II restorations were placed with half the restorations restored with Gluma Solid Bond (a fourth-generation bonding system, or total etch two-step system) and the other half restored with Gluma Comfort Bond and Desensitizer (a fifth-generation bonding system, or total etch one-step system). Solitaire 2 was used as the restorative material for all restorations. The bonding systems and resin composite were used according to the manufacturer’s instructions and all procedures were performed with rubber dam isolation. All restorations were evaluated at baseline, six months and one and two years. A modified USPHS scale was used to evaluate the restorations for marginal discoloration, recurrent caries, anatomic form, marginal adaptation and proximal contact. Statistical analysis revealed that at two years no significant differences were found between the two bonding agents. Overall, Solitaire 2 performed well clinically whether Gluma Solid Bond or Gluma Comfort Bond and Desensitizer was used. It was thus concluded that Solitaire 2 functions successfully when used as a posterior restorative material for at least two years.

SUMMARY:
Thermocycling is commonly employed in laboratory studies to simulate the in vivo aging of restorative materials. However, there is little consistency in the regimens used, and some researchers have questioned the clinical relevance and, hence, the necessity of including thermal stressing in in vitro protocols. This study examined the effects of five thermal stressing regimens on the flexural and dentin bond strengths of a hybrid resin composite. Methods: For flexural strength tests, 95 rectangular specimens (15 mm x 2 mm x 2 mm) were fabricated using a stainless steel split mold, then light cured for 60 seconds. For bond strength tests, 75 caries-free molars were flattened occlusally to expose dentin, then polished through 600 grit SiC paper; dentin surfaces were etched, rinsed and blotted dry. A dentin adhesive was applied and light cured for 30 seconds; resin composite was condensed through a stainless steel split mold (4.3 mm diameter x 3.5 mm high), then light cured for 60 seconds. All specimens were stored in deionized water for 24 hours, then stressed for 100 hours according to one of five regimens: 1) cycled between 5°C and 55°C (9000 cycles; 20-second dwell time); 2) held at 5°C constant; 3) held at 22°C constant; 4) held at 55°C constant; 5) held at 5°C for 50 hours, then at 55°C for 50 hours. Flexural strengths were measured using an Instron 5500R and three-point bending apparatus at a crosshead speed of 0.5 mm/minute. Shear bond strengths were measured using an MTS Bionix 200 at a crosshead speed of 0.5 mm/minute. Results: ANOVA revealed no significant differences in either flexural strength or shear bond strength among the five thermal regimens.

SUMMARY:
Dentinal surfaces prepared with Er:YAG laser have significantly different characteristics from those prepared with conventional instruments. Different hybrid layer morphologies and thicknesses occur, which may result in differences in the quality of restorations placed on dentinal surfaces prepared with a diamond bur when compared with using an Er:YAG Laser. This study compared the hybrid layer thickness and morphology formed utilizing Scotchbond Multipurpose Plus (SBMP) on dentin prepared with a diamond bur in a high speed handpiece and dentin prepared with an Er:YAG laser. Flat dentin surfaces obtained from five human teeth were treated with the two methods and then with the dentin adhesive system according to the manufacturer’s instructions. After a layer of composite was applied, the specimens were sectioned, flattened, polished and prepared for SEM observation. Ten different measurements of hybrid layer thickness were obtained along the bonded surface in each specimen. Results showed that SBMP produced a 3.43 ± 0.75 µm hybrid layer in dentin prepared with a diamond bur. This hybrid layer was regular and constantly found. In the laser group, the dentin adhesive system produced a 1.54 ± 0.35 µm hybrid layer that was very irregular and not found constantly. Statistical analysis of variance (p≤0.05) showed that there was a statistically significant difference between the groups. These data indicate that the Er:YAG laser, with parameters used in the experiment, is not a preparation method that allows for a thick hybrid layer formation, which is in opposition to using a diamond bur in a high speed turbine.

SUMMARY:
Introduction: Adding antibacterial agents to a dentin conditioner used for a glass ionomer cement (GIC) has been shown to be antibacterial; however, it is not known whether this antimicrobial conditioning agent affects the bond strength to dentin in situ. This study applied GIC to antibacterial conditioned dentin without rinsing and determined whether there is an affect on the material’s bond strength.

Materials and Methods: Chlorhexidine acetate (CX), benzalkonium chloride (BC) and cetrimide (CT) were added to Dentin Conditioner (DC) (GC Corp, Japan) at 1% and 5% concentrations. Molars were sectioned coronally to expose dentin, onto which 50 µl of the test conditioners was applied for 20 seconds with a gentle scrubbing action and the residual liquid was blotted dry, as would occur under “field” conditions when performing atraumatic restorative therapy. To serve as the control, the DC was left in situ and compared to the DC that was washed off. Proportioned Fuji IX GIC (GC Corp, Japan) was built-up on the prepared dentin surface and varnish was applied and stored for 24 hours. An annular saw was used to create sticks of GIC bonded to dentin, with a bonding area 1 mm2. After 24 hours, the specimens were tested to failure in a Universal testing machine at a crosshead speed of 1 mm/minute.

Results: Five percent CX-DC was not tested, as it formed a precipitate. Results in MPa: DC-not washed, 9.3 ± 2.4; DC-washed, 9.3 ± 2.5; 1%BC-DC, 8.8 ± 2.5; 1%CX-DC, 8.7 ± 2.7; 1%CT-DC, 8.2 ±1.7; 5%CT-DC, 8.1 ± 2.7; 5%BC-DC, 5.4 ± 1.0. One-way ANOVA showed that there was a significant difference between the test groups (p<0.05), and Tukey’s studentized range test showed that only 5% BC-dentin conditioner left in situ was significantly different from the other groups.

Conclusion: Under the conditions tested, only the 5% BC-DC left in situ affected the bond strength of Fuji IX to dentin.

SUMMARY:
This study evaluated the effects of peroxide bleaching regimens on the ultimate tensile strength (UTS) of human enamel. A resin composite block was built-up on the bonded occlusal surface of 14 extracted, sound, erupted third molars to enable posterior preparation for the microtensile test. The bonded teeth were serially sectioned in a buccal-lingual direction into approximately 0.7-mm thick slices. Each slice was trimmed with a fine diamond bur to reduce the area of the buccal, internal slope of the cusps to a dumb-bell shape with a cross-sectional area of less than 1 mm2. The samples were randomly divided into seven groups (n=10): unbleached control group and bleached groups treated with six bleaching regimens. The specimens were tested in tension at 0.5 mm/minute and the data were analyzed by ANOVA and Tukey test.

Specimens from the control group presented 51.3 ± 8.6 MPa, while the UTS of bleached enamel ranged from 22.0 ± 5.6 to 36.3 ± 9.1 MPa. All bleaching procedures significantly reduced enamel UTS (p<0.05). Differences were also observed among treatments. The results suggested that bleaching regimens can significantly reduce enamel UTS.

SUMMARY:
This in vitro study evaluated the influence of different glass ionomer liners and curing methods on microleakage of resin composite restorations. Class V root preparations were made in 120 bovine incisors randomly divided into 12 groups according to liner and curing method. The resin composite system (Single Bond + Z100) was inserted and polymerized in one increment in all groups. Cavity preparations were either not lined (control), lined with a resin modified glass-ionomer cement (Vitrebond) or a conventional glass-ionomer cement (Ketac Bond). The restorations were light-cured using one of four curing methods. The teeth were thermocycled and immersed in 0.5% basic fuchsin, sectioned, and dye penetration was measured (Image Tool). No significant difference in leakage among conventional, ramp or pulse-delay methods was seen. High intensity light groups showed significantly greater penetration compared to other curing methods. No significant difference existed in marginal leakage between liners, but microleakage was significantly higher in groups restored using no liner. No relationship between lining technique and light curing method was observed. The use of glass ionomer liners reduced microleakage, while high intensity light curing produced the greatest dye penetration.

SUMMARY:
Aim: This study evaluated microleakage at the interface between various temporary restorative materials and existing amalgam or composite restorations, and dental tissues in previously restored teeth after partial removal of the restoration.

Materials and Methods: The distal half of amalgam (Ag) and composite restorations (Co) in 45 teeth were removed, then filled with temporary restorative materials (IRM, Coltosol and CLIP). After thermal cycling, microleakage was measured microscopically as the penetration of basic fuchsine according to a four-unit-scale: The data were evaluated with Friedman and Kruskal-Wallis tests using Bonferroni correction (p<0.05).

Results: In almost all groups except the Co-IRM and Ag-CLIP interface, lower microleakage values were observed in temporary restoration-permanent restoration interfaces compared to temporary restoration-tooth interfaces. For the Ag and Co groups except for the Ag-IRM-b interfaces, the highest microleakage values were observed with IRM for b and c interfaces followed by Coltosol and CLIP. Interestingly, although CLIP was a temporary restoration, CLIP-tooth interface (Ag-CLIP-c) values were lower than amalgam-tooth interface (Ag-CLIP-a) values.

Conclusions: CLIP provided a better seal against microleakage at amalgam and especially composite interfaces. This material also provided a better seal against microleakage at the tooth tissue interface. The use of a resin based temporary restorative material over partially removed resin composite restorations could be beneficial in achieving better resistance to marginal leakage.

Within the limitations of this study, maintaining partially removed permanent restorations does not seem to cause a problem with achieving marginal seal.

SUMMARY:
This study was designed to determine the effects of three factors on the microleakage of a packable resin composite: different adhesive systems (single-step self-etching adhesive or total-etch and one-bottle adhesive), the use of a flowable resin composite (as a liner) and the different techniques of cavity preparation. Sixty extracted non-carious human first and second molars were selected and randomly divided into six groups. Cervical cavities were prepared using the conventional technique on the distal sides and the air-abrasive technique was used on the mesial sides of the teeth. The experimental groups were restored with PQ1 + SureFil or Prompt L-Pop + SureFil with or without PermaFlo. In the control groups, only SureFil was used on 10 teeth and PermaFlo + SureFil was applied on the remaining 10 teeth. The restored teeth were stored in 100% humidity at 37°C for 24 hours and thermocycled between 5°C and 55°C for 100 cycles. Each tooth was immersed in India ink for 48 hours, then sectioned. Dye penetration at the occlusal and gingival margins was scored by two independent operators. The data were statistically analyzed to assess the differences between the test and control groups. No significant differences among the adhesives in terms of the occlusal margins of the cavities were observed. However, PQ1 led to less microleakage compared to Prompt L-Pop at the gingival margins (p<0.0062). When flowable resin composite was used with Prompt L-Pop, microleakage was reduced (p<0.0125). However, no significant difference was observed between the two cavity preparation techniques (p>0.0125).

SUMMARY:
Polymerization shrinkage is an unavoidable consequence of resin composite photopolymerization and is one of the most important factors in determining the clinical quality and durability of composite filling. Many different methods of measuring polymerization shrinkage are described in the literature. Digital laser interferometry is a method that enables direct observation of polymerization shrinkage in real time. This study used the digital holographic interferometry method to measure the linear polymerization contraction of composite materials: Tetric Ceram (Vivadent), Spectrum TPH (Dentsply) and Valux Plus (3M Dental Products) polymerized with three different curing modes of the Elipar Trilight (ESPE) halogen curing unit. The highest polymerization contraction was recorded by “standard mode” (ETS) (1.24±2.66% lin), and the lowest by “medium mode” (ETM) (0.40±0.41% lin) during 40 second illumination. The “exponentional mode” (ETE) showed the highest expansion during the first 10 seconds of illumination. Curing units with initial low intensity enable better inner adaptation of composite material, preventing the detachment of material from dentin during polymerization and avoiding the negative consequences of polymerization shrinkage.

SUMMARY:
This study evaluated the effect of NaOCl treatment of etched air-dried dentin on the bond strength and state of monomer penetration. Ten percent NaOCl was applied after rinsing the etchant and air drying the dentin surface. Wet bonded, untreated teeth were used as a control. The resin composite was bonded and stored in 37°C water for 24 hours, then shear tested. One-way ANOVA, followed by the Duncan test, was done. For Raman microscopy, bonded specimens were cut parallel to the dentinal tubules and polished. Raman spectra were successively recorded along lines perpendicular to the dentin-adhesive interface. The decreased bond strengths found with air-dried dentin increased with NaOCl treatment, but the highest bond strength was obtained with wet bonding. From Raman spectroscopy, the widths of demineralized dentin decreased with prolonged NaOCl treatment time. The patterns of gradual transition of components differed among the groups.

SUMMARY:
Carious lesions around crown margins sometimes lead to failure of fixed prosthodontics. This study examined the influence of metal conditioner application on a dentin surface prior to bonding procedures, using two-step self-etching primer systems. Commercially available metal conditioners and self-etching primer dentin bonding systems were used. Bovine mandibular incisors were mounted in self-curing resin, and the facial dentin surfaces were ground wet on 600-grit SiC paper. The metal primers were applied on the dentin surface followed by bonding procedures with four different types of self-etching primer systems. The resin composites were condensed into a mold on the dentin surface and light activated. Ten specimens per test group were stored in 37°C water for 24 hours; they were then shear tested at a crosshead speed of 1.0 mm/minute. Two-way ANOVA and Tukey’s HSD tests were done. When the metal conditioners were applied on dentin surfaces before bonding procedures, there was a tendency for decreased dentin bond strengths compared to those obtained with the controls. This tendency differed among the combinations of metal conditioners and self-etching primer systems used. Appropriate surface treatments are required to get optimum bond strengths with the use of technique sensitive bonding systems combined with metal conditioners.

SUMMARY:
Considering that caries around restorations is a serious problem in dentistry, and some restorative materials with fluoride may be important in inhibiting these lesions, this research is aimed at performing an in vitro evaluation of the cariostatic action of some esthetic restorative materials. Standardized cavities were prepared in the center of either intact blocks of bovine enamel or with bovine teeth containing early artificial carious lesions. The specimens were restored with a high viscosity glass ionomer cement (Molar Ketac), a resin-modified glass ionomer cement (Vitremer), a polyacid-modified resin composite (Dyract AP) and a conventional resin composite (Z-250). In addition to the restored specimens, four corresponding control groups were evaluated. All groups, except for two control groups, were subjected to a demineralization/remineralization cycling model for 14 days, simulating a situation of severe cariogenic challenge. The blocks were then longitudinally sectioned through the restorations. Mineral loss was evaluated in these specimens using the Knoop microhardness profiles in longitudinal sections at three different distances of the cavities and at eight distinct depths in relation to the external enamel surface. Statistical analysis of the results showed significant differences (p<0.05) among the groups, although none of the study materials completely inhibited creation of the lesions. Vitremer demonstrated the best cariostatic action in intact bovine enamel. Ketac Molar, in intact or demineralized enamel, and Vitremer, in demineralized enamel, presented intermediate cariostatic potential. Z-250 and Dyract AP did not demonstrate any cariostatic effect. The data suggests that glass ionomer cements demonstrated better cariostatic action compared to the other restorative materials.

SUMMARY:
This study evaluated the effect of organic solvent (acetone or ethanol) on the microtensile bond strengths (MTBS) of an adhesive system applied to dry and moist dentin. Sixteen extracted human third molars were ground to expose a flat occlusal dentin surface and acid etched for 20 seconds (20% phosphoric acid gel, Gluma Etch 20 Gel, Heraeus/Kulzer). After rinsing the acid etchant, an ethanol-based one-bottle adhesive system was applied to the mesial half of the occlusal dentin surface. An acetone-based, one-bottle adhesive system was applied to the distal half of the ground dentin surface. The teeth were randomly assigned to groups. In Group 1, the etched dentin was thoroughly air dried and an ethanol-based one-bottle adhesive system was applied (Gluma Comfort Bond, Heraeus/Kulzer) (GCB). In Group 2, the etched dentin was thoroughly air dried and an acetone-based one-bottle adhesive system was applied (Gluma One Bond, Heraeus/Kulzer)(GOB). In Group 3, excess moisture was removed after acid etching, leaving a moist dentin surface and a one-bottle ethanol-based adhesive was applied (Gluma Comfort Bond). In Group 4, excess moisture was removed after acid etching, leaving a moist dentin surface and an acetone-based adhesive was applied (Gluma One Bond). A hybrid resin composite (Venus, Heraeus/Kulzer) was applied to the bonded surface in four 1-mm increments and light cured according to manufacturer’s directions. The specimens were then sectioned with a slow-speed diamond saw in two perpendicular directions to obtain sticks with a cross-section of 0.5 ± 0.05 mm2. The microtensile bond strength (MTBS) test was performed with a Bencor device in an Instron machine at a crosshead speed of 0.5 mm/minute. The data were subjected to a two-way ANOVA and Scheffé Post hoc test (p<0.05). The experimental MTBS measured for dry dentin were Group 1=37.0±10.6 and Group 2=34.7±9.0 in MPa (mean ±SD); and on moist dentin, Group 3=50.7±11.0 and Group 4=38.5±10.5 in MPa (mean ±SD). The ethanol based adhesives resulted in higher MTBS than acetone-based adhesive (p<0.008) and bonding to moist dentin resulted in higher MTBS (p<0.001). GCB applied on moist dentin resulted in statistically higher bond strengths than the other groups. The highest MTBS were achieved with the use of an ethanol-based adhesive to moist dentin.

SUMMARY:
This study evaluated the shear-bond strength of 11 luting cements from different material classes to manufactured pre-treated zirconia ceramics (Lava: 97% ZrO2, stabilized with 3% Y2O3). In addition, the influence of the curing method on shear-bond strength was investigated. The cements examined were one zinc-phosphate cement (Fleck’s zinc cement), two standard glass-ionomer cements (Fuji I, Ketac-Cem), three resin-modified glass-ionomer cements (Fuji Plus, Fuji Cem, RelyX Luting), four standard resin cements (RelyX ARC, Panavia F, Variolink II, Compolute) and one self-adhesive universal resin cement (RelyX Unicem). The ceramic surface was sandblasted with 100-µm alumina or tribochemically coated with silica. After bonding procedure, one group was tested after 30 minutes (Time I), the other group was stored in distilled water at 37°C for 14 days and subsequently thermocycled 1000 times (Time II). Statistical analysis was performed by multifactorial ANOVA models with interactions. For multiple pairwise comparisons, the Tukey method was used. After sandblasting, the highest shear-bond strength was obtained for the self-adhesive universal resin cement at 9.7 MPa (Time I) and 12.7 MPa (Time II), respectively. When using the Rocatec system, the highest values were found for one of the resin cements at 15.0 MPa (Time I) and for the self-adhesive universal resin cement at 19.9 MPa (Time II).

SUMMARY:
This study determined the microhardness and diametral tensile strength of two hybrid resin composites submitted to conventional light curing, which were post-cured with different methods, and compared these data with the same data collected from one indirect resin composite. Two hybrid composites (TPH Spectrum and Filtek P60) and an indirect one (Solidex) were used. Conventional composites were polymerized with 1) conventional light curing for 40 seconds. Additional curing methods were applied with 2) laboratory multi-focal light curing for seven minutes, 3) microwave curing for five minutes at 500W, 4) oven curing for 15 minutes at 100°C, 5) autoclave curing for 15 minutes at 100°C and (6) were polymerized only with a laboratory light curing unit in three increments for three minutes and post-polymerized for seven minutes. The Solidex group was done following the manufacturers’ instructions only. Diametral tensile strength and Knoop hardness tests were applied for all groups of five samples. Data were compared using ANOVA, Tukey and Student t-tests (p<0.05). Post-curing methods increased the Knoop hardness and diametral tensile strength of conventional composites. In general, Filtek P60 showed higher hardness and diametral tensile strength values than TPH Spectrum resin. The Indirect resin composite showed poorer mechanical properties than conventional composites.

SUMMARY:
Gastroesophageal reflux disease (GERD) is a condition where stomach acids are chronically regurgitated into the esophagus and oral cavity, resulting in pathology, such as esophagitis, varices or ulcers. Continual exposure of the teeth to these acids can also cause severe dental erosion. This condition frequently is asymptomatic, and the only evident sign may be the irreversible erosion of tooth structure. The dentist often is the first health care professional to identify the affected dentition. Knowledge of this cause and effect relationship between GERD and dental erosion will better prepare the practitioner to refer patients for appropriate diagnosis and treatment of the underlying medical condition and provide treatment for the affected teeth. This article presents a case report where dental erosion was present due to GERD. After management of the disease with medication, dental treatment of the eroded dentition is described, including diagnosis, treatment planning and restorative reconstruction.

INTRODUCTION:
The patient who arrives at the end of the workday with a catastrophic fracture of a tooth presents both an esthetic and time management challenge to the practitioner. The great majority of these cases will be cuspal fractures of posterior teeth that can usually be addressed by the simple application of glass ionomer cement, since treatment would not involve an esthetically sensitive area (Carroll, 1999). When an anterior tooth is involved, there is often sufficient tooth structure remaining to reattach the fractured segment (Farik & others, 2002; Garcia-Ballesta & others, 2001; Small, 1996; Maia & others, 2003; Vissichelli, 1996). However, a patient will occasionally present with a significant portion or all of the clinical crown missing. Traditional temporary treatment options can be time consuming and unpredictable (Maia & others, 2003; John, Prabhu & Munshi, 1998). Techniques that have been previously described include fabrication of a composite post and core/crown (Howell, 2003), a modification of Croll and Helpin’s (2002) technique of using orthodontic wire and compomer to act as a temporary splint (or, in this case, a fixed partial denture), fabrication of an interim removable partial denture, bonding of a natural tooth pontic and the use of a thermoplastic retainer with composite to replace the missing tooth structure (Blake, Garvey & Fleming, 1998). This paper presents a technique for the immediate interim restoration of a catastrophically fractured maxillary anterior tooth that is fast, non-invasive, esthetic and allows for some limited function without fear of aspiration of tenuously bonded temporary restorative materials.

SUMMARY:
This study evaluated the in vivo effects of bleaching agents containing 10% carbamide peroxide (Platinum/Colgate) or 7.5% hydrogen peroxide (Day White 2Z/Discus Dental) on mutans Streptococcus during dental bleaching. The products were applied on 30 volunteers who needed dental bleaching. In each volunteer, one of the two bleaching agents was used on both dental arches one hour a day for three weeks. Analysis of the bacterial counts was made by collecting saliva before (baseline values), during (7 and 21 days) bleaching treatments and 14 days post-treatment. The Friedman non-parametric analysis (a=0.05) found no differences in micro-organism counts at different times for each group for both agents (p>0.05). The Mann Whitney non-parametric test (a=0.05) showed no differences in micro-organism counts for both agents (p>0.05). Different bleaching agents did not change the oral cavity mutans Streptococcus counts.