^{Microstructural Changes of Different Desensitizing Procedures applied Human Dentinal Tubules after Citric acid exposure: A SEM Analysis.}

Objectives: The aim of this study was to analyze the effect of acidic attack on the different desensitizing procedures including Er:YAG laser and an in-office desensitizing paste alone or their combination applied human dentinal tubules by using SEM analysis.
Methods: Twenty-eight specimens obtained from freshly extracted impacted 3rd molars were included in this study and divided into 4 groups. All specimens were exposed to 1% citric acid in 5 min. Then Group I served as the control there was no treatment applications applied, whereas group II, group III, and group IV received Er:YAG laser, a desensitizing paste (DP) containing 8% arginine and calcium carbonate and DP+Er:YAG laser combination, respectively. Afterwards all treatment groups were submerged into 1% citric acid solution for 3 hours. And then analyzed under SEM.
Results: After 3 hours of re-immersion with citric acid occluded dentinal tubules were still observed in all groups except for the control group. Intergroup comparisons revealed statistically significant difference in favor of the combined group regarding tubule numbers/100 µm²(p<0.05).
Conclusions: It is likely that dentine treated with DP+Er:YAG laser becomes more resistant to acidic attacks promoted by citric acid applications.