Restorative Dentistry Department, Araraquara Dental School, São Paulo State University (Unesp), 14801-903, Araraquara, São Paulo, Brazil.
Dentistry, Endodontic and Dental Materials Department, Bauru Dental School, São Paulo University, 17012-901, Bauru, São Paulo, Brazil.
J Dent. 2018 Aug;75:98-104. doi: 10.1016/j.jdent.2018.06.002. Epub 2018 Jun 9.
To evaluate the effect of desensitizing agent containing calcium phosphate nanoparticles on the bond strength of etch-and-rinse adhesive system (Scotchbond Multi-Purpose), presence of precipitate, dentinal tubule obliteration and hybrid layer formation in dentin in comparison with potassium nitrate plus sodium fluoride or strontium chloride compounds.
150 bovine incisors were treated with (n = 10): G1, Desensibilize Nano P (Ca(PO)+5%KNO+0.9%NaF); G2, Desensibilize (10%SrCl+5%KNO); G3, Desensibilize KF2% (5%KNO+0.2%NaF); G4, Ultra EZ (3%KNO+0.25%NaF) and G5, no treated (control). Scanning electron microscopy was used to assess the incidence of precipitates (500×) and obliterated dentinal tubule counts (1.000×). The adhesive system was used after all desensitization treatments. The bond strength (n = 40) and the fracture pattern were evaluated. Confocal laser microscopy was used to quantify the hybrid layer formation in dentin.
G1 and G2 presented higher adhesive system bond strength (MPa) than G4 and G5, however no significant differences were observed in comparison with G3. Cohesive fracture was frequently found: G1 (58.5%), G2 (51.3%) and G3 (43.8%). G1 showed the highest incidence of precipitates and the highest number of blocked dentinal tubules. G1 and G2 presented similar hybrid layer formation and the highest hybrid layer formation values.
Desensibilize Nano P (G1) favored the bond strength of the adhesive system to dentin, increased the precipitation of residues, obliteration of dentinal tubules, and hybrid layer formation in comparison with other agents.
Desensitizers promote dentin obliteration, however, may affect dentin bonding.
评估含有磷酸钙纳米粒子的脱敏剂对蚀刻-冲洗型黏结剂系统（Scotchbond Multi-Purpose）的黏结强度、沉淀物的存在、牙本质小管封闭和牙本质中混合层形成的影响，并与硝酸钾加氟化钠或氯化锶化合物进行比较。
对 150 颗牛切牙进行处理（n=10）：G1，Desensibilize Nano P（Ca(PO)+5%KNO+0.9%NaF）；G2，Desensibilize（10%SrCl+5%KNO）；G3，Desensibilize KF2%（5%KNO+0.2%NaF）；G4，Ultra EZ（3%KNO+0.25%NaF）和 G5，未处理（对照组）。使用扫描电子显微镜评估沉淀物的发生率（500×）和封闭牙本质小管的数量（1000×）。所有脱敏处理后使用黏结剂系统。评估黏结强度（n=40）和断裂模式。使用共聚焦激光显微镜定量评估牙本质中混合层的形成。
G1 和 G2 的黏结系统黏结强度（MPa）高于 G4 和 G5，但与 G3 相比无显著差异。常见的断裂模式为内聚性断裂：G1（58.5%）、G2（51.3%）和 G3（43.8%）。G1 显示出最高的沉淀物发生率和最高数量的封闭牙本质小管。G1 和 G2 具有相似的混合层形成和最高的混合层形成值。
与其他试剂相比，Desensibilize Nano P（G1）有利于黏结剂系统与牙本质的黏结强度，增加了残留物的沉淀、牙本质小管的封闭和牙本质中的混合层形成。
脱敏剂可促进牙本质封闭，但可能会影响牙本质黏结。
