مقايسه كاربرد ليزر Nd: YAG و ماده Seal & Protect بر سختي عاج

Comparison of Nd:YAG laser and ˜Seal & protect˜ sealant on dentin microhardness

Background & Aim: Several treatment methods have been suggested for reduction of dentin hypersensitivity such as Nd:YAG laser and Seal & Protect sealant materials. However, the effects of these methods have not been yet evaluated on dentin microhardness. The aim of this study was to compare the effect of Nd:YAG laser and Seal & Protect sealant on microhardness of dentin by using Vickers indicator. Materials & Methods: This in-vitro experimental study was conducted on forty-five freshly extracted human third molars. The buccal enamel surface was removed in order to expose the underneath dentin. Samples were randomly divided into three groups. Group one, received no treatment as controls, group two were exposed to Nd:YAG laser (1 W,10 Hz ,2 min) and the samples in third group were treated by Seal & Protect. Indentations were performed using Vickers indentor at 100 gr. load. Finally the average hardness number was calculated and statistical analysis was done with ANOVA and LSD tests. Results: The results of this study demonstrated that Nd:Yag laser irradiation can increase dentin microhardness. However, it was not statistically significant (P>0.05) when compared with control group. Low level dentin microhardness was detected in Seal & Protect group when compared to other groups (P=0.01). Also, there was significant difference between the Nd:Yag laser and Seal & Protect groups (P<0.05). Conclusion: Nd:YAG laser irradiation for treatment of dentin hypersensitivity didnʹt decrease dentin microhardness. In contrary, using Seal & Protect can decrease dentin microhardness