Department of Orthodontics and Department of Surgical Sciences (Head: Prof. Paolo Dionigi), University of Pavia, Pavia, Italy.
Med Oral Patol Oral Cir Bucal. 2013 Jan 1;18(1):e162-7. doi: 10.4317/medoral.18246.
The aim of this study was to assess the effect of blood contamination on the shear bond strength and failure site of three different orthodontic self-ligating brackets.
240 bovine permanent mandibular incisors were randomly divided into 12 groups of 20 specimens each. Orthodontic self-ligating brackets were tested under four different enamel surface conditions: a) dry, b) blood contamination before priming, c) blood contamination after priming, d) blood contamination before and after priming. Brackets were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values), and Chi squared test (ARI Scores).
Non-contaminated enamel surfaces showed highest bond strengths for all self ligating brackets. Under blood-contamination shear bond strengths lowered for all brackets tested. Groups contaminated before and after primer application showed the lowest shear bond strength. Significant differences in debond locations were found among the groups under the various enamel surface conditions.
Blood contamination of enamel during the bonding procedure lowers bond strength values of self ligating brackets, expecially when contamination occur in different times of the bonding procedure.
本研究旨在评估三种不同的正畸自锁托槽在血液污染时对其剪切粘结强度和失效部位的影响。
240 个牛恒切牙被随机分为 12 组，每组 20 个样本。正畸自锁托槽在四种不同的牙釉质表面条件下进行测试：a）干燥，b）预固化前的血液污染，c）预固化后的血液污染，d）预固化前后的血液污染。将托槽粘结到牙齿上，然后使用 In stron 万能试验机进行测试。记录剪切粘结强度值和粘结剂失效率。使用方差分析和 Tukey 检验（强度值）和卡方检验（ARI 评分）进行统计分析。
未污染的牙釉质表面对所有自锁托槽均显示出最高的粘结强度。所有测试的托槽在血液污染下的剪切粘结强度均降低。在预固化前后污染的组显示出最低的剪切粘结强度。在不同牙釉质表面条件下，粘结部位的差异有统计学意义。
在粘结过程中牙釉质的血液污染会降低自锁托槽的粘结强度值，特别是当污染发生在粘结过程的不同时间时。
