Abstract：
This study aimed to evaluate the influence of radiotherapy and different endodontic treatment protocols on the bond strength to pulp chamber dentin. Eighty mandibular molars were randomly divided into two groups (n = 40): non-irradiated and irradiated (60 Gy). The pulp chambers were sectioned, and each group was subdivided (n = 8), according to the endodontic treatment protocol: no treatment (Control); Single-visit; Two-visits; Immediate dentin sealing (IDS) + single-visit; and IDS + two-visits. Each endodontic treatment visit was simulated through irrigation with 2.5% NaOCl, 17% EDTA and distilled water. IDS was performed by actively applying two coats of a universal adhesive to the lateral walls of the pulp chamber. After, the pulp chambers were restored with resin composite and four sticks were obtained for microtensile test. In addition, the dentin of the pulp chamber roof was assessed for surface roughness, chemical composition, and topography after each treatment protocol. Two-way ANOVA, Tukey\'s post hoc, Mann-Whitney, Kruskal-Wallis and Dunn\'s post hoc were performed (α = 5%). The treatment protocol affected bond strength (p < 0.05), while the irradiation did not (p > 0.05). The control group presented the highest values (p < 0.05). The single-visit group demonstrated better performance compared to the other groups (p < 0.05), which did not differ from each other (p > 0.05) The use of IDS changed the surface roughness (p < 0.05), chemical composition (p < 0.05) and topography of the dentin. In conclusion, the treatment protocol influenced dentin adhesion, while irradiation did not.
摘要：
本研究旨在评估放射治疗和不同牙髓治疗方案对牙髓腔牙本质粘结强度的影响。将80颗下颌磨牙随机分为两组（n=40）：未辐照和辐照（60Gy）。纸浆室被剖开，每组被细分（n=8），根据牙髓治疗方案：不治疗（对照）；单次访问；两次访问；立即牙本质密封（IDS）单次访问；和IDS两次访问。每次牙髓治疗都是通过用2.5%NaOCl灌溉来模拟的，17%EDTA和蒸馏水。IDS是通过在纸浆室的侧壁上积极施加两层通用粘合剂来进行的。之后，用复合树脂修复纸浆室，并获得四根棒进行微拉伸试验。此外,评估牙髓室屋顶的牙本质的表面粗糙度，化学成分,和每个治疗方案后的地形。双向方差分析,Tukey的posthoc,Mann-Whitney,Kruskal-Wallis和Dunn的事后表现（α=5％）。处理方案影响粘结强度(p<0.05)，而照射没有(p>0.05)。对照组呈现最高值(p<0.05)。与其他组相比，单次访视组表现更好（p<0.05），它们之间没有差异(p>0.05)。使用IDS改变了表面粗糙度(p<0.05)，牙本质的化学成分(p<0.05)和形貌。总之,治疗方案影响牙本质粘连，而辐照没有。
