Objectives: This study aimed to compare the shear bond strength (SBS) of self-adhesive and conventional flowable composites and resin-modified glass-ionomer cement (RMGIC) to primary dentin. Materials and Methods: In this in vitro, experimental study, the buccal surface of 48 primary canine and first molar teeth was longitudinally sectioned to expose dentin. The teeth were randomly divided into three groups (n=16) of 37.5% phosphoric acid+ OptiBond+ Premise Flow composite (group 1), Vertise Flow composite (group 2) and RMGIC (group 3). A plastic cylindrical mold was placed on the exposed dentin and filled with restorative materials. The samples were then immersed in distilled water at 37°C for 24 hours, subjected to 1000 thermal cycles between 5-55°C and underwent SBS test. The mode of failure was determined under a stereomicroscope. Data were analyzed using one-way ANOVA and Tukey’s test. Results: A significant difference was noted in SBS of the groups (P<0.05). The SBS of conventional flowable composite was significantly higher that of RMGIC and self-adhesive flowable composite (P<0.05). The difference in SBS of RMGIC and self-adhesive flowable composite was not significant (P>0.05). Failure at the dentin-restoration interface (adhesive failure) had the highest frequency in groups 1 and 2. The frequency of adhesive failure was 100% in group 3. Conclusions: Within the limitations of this study, the conventional flowable composite yielded the highest SBS to primary dentin. Self-adhesive flowable composite and RMGIC showed the lowest SBS with no significant difference with each other.

Background: This study sought to assess the effect of Er,Cr:YSGG laser power on the surface roughness of lased radicular dentin using atomic force microscopy (AFM). Methods: Fifteen human radicular dentin samples were randomly divided into five groups: one control (G1, intact) and four experimental groups treated with 0.25W (G2), 0.5W (G3), 0.75W (G4) and 1W (G5) powers of Er,Cr:YSGG laser (2.78µm) at a repetition rate of 20 Hz, with a 600-µm-diameter sapphire tip. After irradiation, surface topography was analyzed by AFM using a Si probe in tapping mode. Quantitative information concerning the arithmetic average roughness (Ra) and quadratic mean roughness (Rq) was obtained from three 5×5µm areas of each sample. The data were analyzed using one-way ANOVA (P<0.05). Results: The Ra and Rq values increased in G2 and G5 and decreased in G3 and G4 groups compared to the control group. The maximum Ra and Rq values were noted in G5, which were significantly higher than the corresponding values in G3 (P<0.05). Conclusion: No direct correlation was found between Er,Cr:YSGG laser power and surface roughness of lased radicular dentin. Laser therapy with a mean power of 0.5W and 1W caused the lowest and highest surface roughness, respectively.

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Objectives: Application of fissure sealants is a practical method for prevention of occlusal pit and fissure caries. Microleakage is an important factor affecting the success of fissure sealant treatment. This study aimed to assess the microleakage of a self-adhesive flowable composite, a self-adhesive fissure sealant and a conventional fissure sealant in permanent teeth with/without saliva contamination. Materials and Methods: This in vitro, experimental study evaluated 108 extracted human third molars, which were randomly divided into six groups (n=18) of control, Denu-Seal conventional fissure sealant applied on etched enamel with/without saliva contamination, Vertise Flow self-adhesive flowable composite applied on rinsed and dried enamel with/without saliva contamination and Prevent Seal self-adhesive fissure sealant applied on rinsed and dried enamel with/without saliva contamination. Microleakage was assessed using the dye penetration technique and subsequent observation of samples under a stereomicroscope. Data were analyzed using the Kruskal-Wallis and Tukey’s test. Results: Microleakage of the conventional fissure sealant with/without saliva contamination was significantly lower than that of other groups (P<0.05). Conclusion: Microleakage of the conventional fissure sealant is less than that of self-adhesive fissure sealant and self-adhesive composite, irrespective of saliva contamination.

Background The main purpose of this experimental study was to determine the in vitro effects of two calcium phosphate‐containing agents (Remin Pro® and GC Tooth mousse™) on the enamel resistance of permanent molars to demineralization. Methods Fifty extracted human third molars were randomly divided into four groups; that is the control group and three case groups treated with Remin Pro®, GC Tooth mousse™, and sodium fluoride gel. The three case groups were treated with 0.25 ml of the paste associated with each experimental group for 5 min, kept in fluoride‐free artificial saliva, and incubated at 37°C for 28 days. After the treatment regimen, 10 samples of each case group were subjected to demineralization using an acetic acid‐containing solution, and remineralization using a remineralizing solution. The morphology of enamel was observed via scanning electron microscopy and their enamel calcium/phosphorus (Ca/P) ratios were measured before/after the demineralization cycle with energy‐dispersive X‐ray analysis. Data were statistically analyzed using one‐way analysis of variance and post hoc Tukey tests. Results The enamel Ca/P ratios in the case study groups were significantly higher than that of the control group before/after the demineralization regimen (p < .0001). However, the ratios were not significantly different between the case study groups after the treatment regimen and demineralization cycle (p > .05). Conclusion The outcomes of the current study indicated that all three agents seemed to increase the enamel resistance of permanent molar teeth to demineralization.