Occluding Efficiency of Different Desensitizing Agents and Er,Cr:YSGG Laser on Dentin Tubules.

PURPOSE: This study aimed to evaluate the effects of two desensitizers and the Er,Cr:YSGG laser on human dentin tubules, applied alone or in combination. METHODS: Ninety-six dentin specimens were obtained from extracted third molars and divided into six groups: Group 1: no-treatment (Control); Group 2: nano-hydroxyapatite desensitizer (NhapD); Group 3: NhapD+Er,Cr:YSGG laser (L); Group 4: Er,Cr:YSGG laser (L); Group 5: glutaraldehyde desensitizer (GD); and Group 6: GD+L, respectively. All specimens were evaluated using scanning electron microscopy. The diameter and the number of open dentin tubules, the tubules' occluding ratio, and the mineral coverage area were measured via the Image J software at 2000× magnification. Atomic force microscopy was used to determine the blocking mechanism of desensitizing treatments and the surface morphology of dentin specimens. One-way ANOVA and Tukey tests were used for statistical analysis. RESULTS: The number of open tubules and the mean diameter of tubules for all treatment groups showed statistically significant differences from the control group The NhapD+L group had a significantly lower number of open tubules than the L and GD groups. The NhapD+L and L groups significantly had higher occluding ratios than the other groups. CONCLUSIONS: The present study showed that the Er,Cr:YSGG laser alone was effective in terms of tubule occlusion and also contributed to increasing the occluding ratio of nano-hydroxyapatite. It may be recommended to use the Er,Cr:YSGG laser with nano-hydroxyapatite desensitizers to achieve effective tubule occlusion.

Effects of different pediatric drugs and toothbrushing on color change of restorative materials used in pediatric dentistry.

OBJECTIVE: The purpose of this study was to evaluate the effects of different pediatric drugs and toothbrushing on color changes of restorative materials used in pediatric dentistry. MATERIALS AND METHODS: Sixty specimens were prepared from each of three restorative materials (compomer [Dyract XP], glass hybrid [Equia Forte], and glass carbomer [GCP Glass Fill]). Specimens were divided into six solution groups (n = 10) and immersed in five different pediatric drugs (antibiotic, analgesic, common cold syrup, cough syrup, and an iron and vitamin formula) and distilled water. Two subgroups (brushed and unbrushed) were established for each group (n = 5). Specimens were agitated for 1 min every 8 h over 2 weeks. Color changes [CIEDE2000 (ΔE00)] were calculated at baseline, 7, and 14 days. Data were subjected to 4-factor mixed-design ANOVA using a general linear model procedure for repeated measurements. RESULTS: After 14 days, the highest ΔE00was found in the compomer/non-brushing group immersed in iron and vitamin formula (5.6 ± 0.27), and the lowest was in glass hybrid/brushing group immersed in distilled water (0.59 ± 0.8) pairwise. ΔE00values were significantly greater for compomer than for glass hybrid or glass carbomer (P < 0.05). There were statistically significant differences between the brushing and non-brushing groups for all tested solutions on the compomer specimens (except antibiotic) and glass hybrid specimens (except antibiotic and cough syrup). The Δ00 values in brushing groups were significantly lower statistically than in non-brushing groups (P < 0.05). CONCLUSIONS: Toothbrushing dramatically affected the color stability of the aesthetic restorative materials. The content of pediatric drugs is also an important factor for color change. Glass hybrids and glass carbomers used with their surface sealants appeared to be more resistant to staining from pediatric drug formulations than compomers.

The effect of calcium phosphate-containing desensitizing agent on the microtensile bond strength of multimode adhesive agent.

OBJECTIVE: The aim of this study was to investigate the effect of calcium phosphate containing desensitizing pretreatments on the microtensile bond strength (MTBS) and microleakage of the multimode adhesive agent to dentin. MATERIALS AND METHODS: In this study, twelve noncarious, freshly extracted human third molar teeth for MTBS and 20 premolar teeth for the microleakage test were used. The teeth were restored using Clearfil Universal Bond + Clearfil APX and Teeth mate Desensitizer (TMD). For MTBS test, Group 1: Self-etch, Group 2: Etch and rinse (G1 and 2, nondesensitizer treatment served as a control), Group 3: TMD/self-etch, Group 4: Acid-etch/TMD/etch and rinse. For microleakage test, Class V adhesive cavities (3 mm × 2 mm × 2 mm) were prepared and restored as mentioned before. The restored teeth were subjected to thermal cycling. The MTBS test was performed in all procedures. The MTBS data were submitted to a one-way ANOVA and post hoc Tukey test (P P Results: Control groups exhibited a higher mean MTBS value than TMD groups, and there were statistical differences between the groups. TMD groups also demonstrated significantly less microleakage than control groups (P Conclusions: This study proves that the application of TMD with a multimode adhesive bonding system produced significantly lower MTBS and microleakage.