Cossellu Gianguido, Lanteri Valentina, Butera Andrea, Laffi Nicola, Merlini Alberto, Farronato Giampietro
Department of Biomedical, Surgical and Dental Sciences, School of Dentistry, University of Milan, Milan, Italy.
Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy.
J Orthod Sci. 2017 Jan-Mar;6(1):11-15. doi: 10.4103/2278-0203.197392.
To assess the best temporal association between the application of a fluoride varnish on enamel and bonding procedures.
Eighty mandibular bovine incisors were used. Teeth were divided into 4 groups (20 per group); Groups 1-3 were treated with fluoride varnish (Fluor Protector, Ivoclar Vivadent, Schaan, Liechtenstein), and Group 4 served as control with no pretreatment. Tooth were stored in deionized water (37°C) and subjected to thermal cycling for 400 (Group 1), 800 (Group 2), and 2500 (Group 3) cycles corresponding, respectively, to 15, 30, and 90 days in order to simulate the three different timing of bracket bonding. Shear bond strength (SBS) was measured using an Instron Universal Testing machine. Tooth surfaces were examined under a stereomicroscope at 10× magnification to assess the amount of adhesive remnant index (ARI). One-way analysis of variance (ANOVA) and Tukey's honestly significant difference post-hoc test were used for the comparison of SBS values between groups ( < 0.05). The Chi-square test was used to examine differences among ARI scores. ( < 0.05).
One-way ANOVA and Tukey post-hoc test showed that the SBS of different groups were significantly different and was impacted by different timing of bonding ( < 0.05). The main differences were between the control group (17.02 ± 6.38 MPa) and Group 1 (6.93 ± 4.3 MPa). The ARI scores showed that there were no significant differences between the four tested groups.
The SBS of the brackets bonded 15 days after the application of the fluoride was set back to an optimal value.
评估在牙釉质上涂抹氟化物清漆与粘结操作之间的最佳时间关联。
使用80颗下颌牛切牙。牙齿分为4组（每组20颗）；第1 - 3组用氟化物清漆（氟保护漆，义获嘉伟瓦登特公司，沙恩，列支敦士登）处理，第4组作为未预处理的对照组。牙齿保存在去离子水中（37°C），并分别进行400次（第1组）、800次（第2组）和2500次（第3组）热循环，分别对应15天、30天和90天，以模拟三种不同的托槽粘结时间。使用英斯特朗万能材料试验机测量剪切粘结强度（SBS）。在立体显微镜下以10倍放大率检查牙齿表面，以评估粘结剂残留指数（ARI）。采用单因素方差分析（ANOVA）和Tukey真实显著差异事后检验比较各组间的SBS值（<0.05）。采用卡方检验检查ARI评分之间的差异（<0.05）。
单因素方差分析和Tukey事后检验表明，不同组的SBS有显著差异，且受不同粘结时间的影响（<0.05）。主要差异存在于对照组（17.02±6.38 MPa）和第1组（6.93±4.3 MPa）之间。ARI评分显示，四个测试组之间没有显著差异。
在涂抹氟化物15天后粘结的托槽的SBS恢复到最佳值。
