Lohfeld Stefan, Kawamoto Burt, Wang Yong, Walker Mary P
Department of Oral and Craniofacial Science, School of Dentistry, University of Missouri-Kansas City, 650 E 25th St., Kansas City, MO, 64108, USA.
Odontology. 2023 Jan;111(1):85-92. doi: 10.1007/s10266-022-00724-6. Epub 2022 Jun 30.
To determine the effect of fluoride varnish application combined with a simulated oral environment prior to bracket bonding on the shear bond strength (SBS) between brackets and tooth enamel. Sixty de-identified, extracted teeth were grouped to either receive or not receive fluoride varnish and then stored for 7 days at 37 °C in phosphate-buffered saline (PBS) solution or PBS combined with three 15-min cycles/day in a demineralizing solution to simulate pH variation following meals. Subsequently, brackets were bonded and after 24-h dark cure at 37 °C, debonded using shear forces in a simulated oral environment. The maximum shear force was used to calculate SBS, and the adhesive remnant index (ARI) was determined by image analysis of photos of the bracket mesh pad after debonding. A statistically higher SBS (10.16 MPa) was observed when fluoride varnish was applied prior to storage in PBS + demineralizing solution compared to SBS (6.38 MPa) following storage in the same solution without varnish application. Based on 37% effect size, this difference is also clinically relevant. In contrast, no significant differences in SBS were observed with varnish application combined with PBS with no demineralizing solution or between storage solution alone. Moreover, there was no significant difference in ARI due to varnish combined with either storage method or storage solution only. Results suggest varnish application prior to bracket bonding in combination with simulated oral environment that included acid exposure is beneficial in maintaining higher SBS between bracket and enamel. Despite higher SBS, adhesive remaining on enamel did not increase.
为确定在托槽粘结前应用含氟涂料并结合模拟口腔环境对托槽与牙釉质之间剪切粘结强度（SBS）的影响。60颗匿名的离体牙被分组，分别接受或不接受含氟涂料处理，然后在37℃下于磷酸盐缓冲盐水（PBS）溶液中或PBS与每天3次、每次15分钟的脱矿溶液联合处理中储存7天，以模拟进食后的pH变化。随后，粘结托槽，并在37℃下黑暗固化24小时后，在模拟口腔环境中使用剪切力使其脱粘。用最大剪切力计算SBS，并通过对脱粘后托槽网垫照片的图像分析确定粘结剂残留指数（ARI）。与在相同溶液中未应用含氟涂料而储存后的SBS（6.38MPa）相比，在PBS +脱矿溶液中储存前应用含氟涂料时观察到统计学上更高的SBS（10.16MPa）。基于37%的效应量，这种差异在临床上也具有相关性。相比之下，在应用含氟涂料并结合不含脱矿溶液的PBS时，或仅在储存溶液之间，SBS没有显著差异。此外，由于含氟涂料与任何一种储存方法或仅储存溶液联合使用，ARI也没有显著差异。结果表明，在托槽粘结前应用含氟涂料并结合包括酸暴露的模拟口腔环境，有利于维持托槽与牙釉质之间更高的SBS。尽管SBS较高，但留在牙釉质上的粘结剂并未增加。
