不同处理方法对树脂面与托槽粘接强度的影响

背景:树脂表面不同处理方法对金属托槽和树脂面的粘接强度可能有直接影响.目的:观察不同表面处理方法对金属托槽与光固化复合树脂修复体粘接抗剪切强度的影响.设计、时间及地点:对比观察实验,于2006-05/2007-04佳木斯大学口腔生物材料实验室完成.材料:制作20个双面充光固化复合树脂的长方块,共计40个树脂面,随机分为乙醇组、打磨组、酸蚀组、酸蚀+硅烷组,每组10个树脂面.方法:乙醇组:用蘸有体积分数为75%乙醇溶液的棉球擦拭树脂面,自然晾干.打磨组:使用钨钢麻花钻打磨树脂面中央使粘接面粗糙,打磨面积稍大于托槽底面积,用无油水气枪冲洗15 s,吹干.酸蚀组:9.6%氢氟酸酸蚀树脂面2 min,酸蚀面积稍大于托槽底面积,蒸馏水冲洗20 s,吹干.酸蚀+硅烷组:9.6%氢氟酸酸蚀处理同上,再在酸蚀的树脂面上均匀涂布一层硅烷偶联剂.在处理过的树脂面上均匀涂布一薄层光固化复合树脂底胶光固化灯照射20 s,将适量复合树脂置于托槽底部,以均匀适当的压力将托槽就位去除托槽周围多余的树脂,用光固化灯从托槽的近远中方向分别照射40 s使其固化粘接.主要观察指标:所有样品储存在37℃水中24 h后,5～55℃冷热循500次.将样品置于电子万能试验机下进行抗剪切强度的测试.并在10倍放大镜下观察树脂面破坏情况.结果:打磨组、酸蚀+硅烷组的抗剪切强度明显高于乙醇组和酸蚀组(P<0.01),打磨组树脂面破损率高于其他组,但各组差异无显著性意义(P>0.05).结论:氢氟酸酸蚀+硅烷偶联剂联合使用可提高金属托槽与光固化复合树脂修复体粘接的抗剪切强度,硅烷偶联剂的使用增加了托槽与树脂面的粘接强度.

Effects of different surface treatments on shear bonding strength between brackets and resin veneers

BACKGROUND: Surface preparation of resin can directly influence the shear strength of orthodontic brackets bonded to resin surface.OBJECJIME: To compare the effects of various surface treatments on the shear bonding strength between metal brackets and resin surfaces.DESIGN, TIME AND SETTING: A comparative observation was performed at the Oral Biomaterials Laboratory of Jiamusi University from May 2006 to April 2007.MATERIALS: A total of 40 resin surfaces were randomly divided into four equally-sized groups: alcohol cleansing group (Group A), grinded group (Group B), 9.6% hydrofluoric group (Group C), and 9.6% hydrofluoric combined with silane group (Group D), with 10 surfaces in each group.METHODS: Alcohol cleansing group: Ten resin specimens were surface treated with 75% alcohol and dried. Grinded group: The central of resin surface in this group were microetched with Tungsten steel twist drill and washed with oil-free compressed air. 9.6% hydrofluoric group: The resin specimens were etched with 9.6% hydrofluoric acid for 2 minutes, washed with distilled water for 20 s, and dried. The etching acreage was greater than the bracket base. 9.6% hydrofluoric combined with silane group: The resin surface in this group was etched with 9.6% hydrofluoric acid as group C. After thoroughly etching the resin surface with 96% hydrofluoric acid, the silane was then applied to the resin surface and dried with oil-free compressed air. A lay of the bonding resin to all specimens was then thinned and light-cured for 20 s. During the bonding procedure, each bracket was subject to an identical compressive force. Any excess bonding resin around the brackets was removed using a sharp scatter. Finally, specimens were light-cured for 40 s.MAIN OUTCOME MEASURES: Specimens were stored in water at 37℃ for 24 hours and subsequently thermocycled between 5 and 55℃ for 500 cycles. The resin surfaces were subsequently re-examined to measure shear strength and observe resin surface fracture with stereomicroscopy (×10).RESULTS: The shear bonding strength in the grinded group and 9.6% hydrofluoric combined with silane group was much greater than that in the alcohol cleansing group and 9.6% hydrofluoric group (P < 0.01). The ratio of resin fracture in the grinded group was higher than that in other groups, but there was no significant difference between the four groups (P > 0.05).CONCLUSION: 9.6% hydrofluoric combined with silane can enhance the shear bonding strength. The use of silane prior to bonding is the single most important factor in determining satisfactory bond strength.