Francisconi-dos-Rios Luciana Fávaro, Casas-Apayco Leslie Caroll, Calabria Marcela Pagani, Francisconi Paulo Afonso Silveria, Borges Ana Flávia Sanches, Wang Linda
J Adhes Dent. 2015 Apr;17(2):133-9. doi: 10.3290/j.jad.a34059.
To assess the long-term effect of a 2% aqueous chlorhexidine (CHX) solution on bond strength to artificially eroded dentin compared to sound dentin.
Flat mid-coronal dentin surfaces of extracted third molars (n = 28) were subjected only to grinding with a 600-grit SiC paper for 1 min (sound dentin S, n = 14) or additionally to erosive pH cycling with a cola-based soft-drink (eroded dentin E, n = 14). After acid etching, rinsing, and air drying, S and E were rehydrated with 1.5 μl of 2% CHX (S2%, n = 7; E2%, n = 7) or of distilled water (control SC, n = 7; EC, n = 7). Composite buildups were incrementally constructed with Filtek Z350 following Adper Single Bond 2 application. Specimens were sectioned into beams, which were subjected to microtensile testing immediately or after 6 or 12 months of aging. Fractured surfaces were observed under a digital microscope (50X magnification). Microtensile bond strength (μTBS) (MPa) was analyzed by three-way ANOVA and Tukey's tests (α = 0.05) and failure mode by the Kruskal-Wallis test (α = 0.05).
Compared to sound dentin, eroded dentin was consistently related to lower μTBS. Immediately and after 12-month aging, the effect of CHX was insignificant, but it was significant after 6-month aging, when it conserved the bond strength to both eroded and sound dentin. The percentage of adhesive and mixed failures were equivalent, and significantly more frequent than cohesive failures, whether in dentin or in composite.
The 2% CHX effect on bond strength conservation to both eroded and sound dentin was not found to be persistent.
评估2%洗必泰（CHX）水溶液与健康牙本质相比，对人工侵蚀牙本质粘结强度的长期影响。
将拔除的第三磨牙（n = 28）的牙冠中份平坦牙本质表面仅用600目碳化硅砂纸打磨1分钟（健康牙本质S，n = 14），或额外用可乐型软饮料进行侵蚀性pH循环处理（侵蚀牙本质E，n = 14）。酸蚀、冲洗和空气干燥后，S组和E组分别用1.5 μl 2% CHX（S2%，n = 7；E2%，n = 7）或蒸馏水（对照组SC，n = 7；EC，n = 7）进行再水化处理。按照Adper Single Bond 2粘结剂的使用说明，使用Filtek Z350复合树脂逐步构建修复体。将样本切成小梁，立即或在老化6个月或12个月后进行微拉伸试验。在数码显微镜（50倍放大）下观察断裂表面。通过三因素方差分析和Tukey检验（α = 0.05）分析微拉伸粘结强度（μTBS）（MPa），通过Kruskal-Wallis检验（α = 0.05）分析失效模式。
与健康牙本质相比，侵蚀牙本质的μTBS始终较低。即刻和12个月老化后，CHX的作用不显著，但在6个月老化后显著，此时它能保持对侵蚀牙本质和健康牙本质的粘结强度。无论是在牙本质还是在复合树脂中，粘结和混合失效的百分比相当，且显著高于内聚性失效。
未发现2% CHX对侵蚀牙本质和健康牙本质粘结强度的保持作用具有持续性。
