Department of orthodontics, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.
Department of orthodontics, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.
Int Orthod. 2021 Jun;19(2):259-268. doi: 10.1016/j.ortho.2021.03.001. Epub 2021 Mar 26.
To evaluate the effects of remineralizing agents on the shear bond strength (SBS) of orthodontic brackets bonded to intact and demineralized enamel.
In this in-vitro study, 160 human premolars were divided into 8 groups, including group 1 with intact enamel as the positive control, group 2 with demineralized enamel as the negative control, groups 3-5 treated with fluoride varnish, Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) and resin infiltrant on intact enamel, and groups 6-8 treated with the same agents on demineralized enamel. Brackets were bonded using the conventional method, and the samples were thermocycled. SBS of the brackets was measured using a universal testing machine, and the adhesive remnant index (ARI) was assessed. Data were analysed with one-way ANOVA and post hoc statistical test at the significance level of 0.05.
SBS of the brackets in all groups with intact enamel was higher than that of their counterparts on demineralized enamel, which was only significantly different between groups 1 and 2 (P-value<0.001). SBS values of groups 7 and 8 were not significantly different from group 1 (P-value=1), yet the application of fluoride varnish on both intact (P-value=0.091) and demineralized enamel (P-value<0.001) created less SBS than in group 1.
All pre-treatment methods increased SBS of the brackets bonded to demineralized enamel, yet only the resin infiltrant and CPP-ACP produced SBS similar to that of intact enamel. Also, the use of fluoride varnish on intact enamel significantly reduced SBS.
评估再矿化剂对粘结至完整釉质和脱矿釉质的正畸托槽的剪切粘结强度（SBS）的影响。
在这项体外研究中，将 160 个人类前磨牙分为 8 组，包括 1 组为完整釉质作为阳性对照组，2 组为脱矿釉质作为阴性对照组，3-5 组用氟化物漆、酪蛋白磷酸肽-无定形磷酸钙（CPP-ACP）和树脂渗透剂处理完整釉质，6-8 组用相同的试剂处理脱矿釉质。使用常规方法粘结托槽，然后进行热循环。使用万能试验机测量托槽的 SBS，并评估黏附残余指数（ARI）。使用单因素方差分析和事后统计检验，在 0.05 的显著性水平下对数据进行分析。
所有完整釉质组的托槽 SBS 均高于脱矿釉质组，仅在 1 组和 2 组之间差异有统计学意义（P 值<0.001）。7 组和 8 组的 SBS 值与 1 组无显著差异（P 值=1），但氟化物漆在完整釉质（P 值=0.091）和脱矿釉质（P 值<0.001）上的应用均导致 SBS 低于 1 组。
所有预处理方法均增加了粘结至脱矿釉质的托槽的 SBS，但只有树脂渗透剂和 CPP-ACP 产生的 SBS 与完整釉质相似。此外，氟化物漆在完整釉质上的使用显著降低了 SBS。
