不同粘结剂对轻、中、重度氟斑牙釉质粘结强度的比较

The bonding strength of different adhesives on mild, moderate and severe dental fluorosis enamel： A comparative study

目的观察2种粘结剂对轻、中、重度氟斑牙釉质的粘结强度，为临床上不同程度氟斑牙粘结剂的选择提供依据。方法在内蒙古医科大学附属医院，根据Dean分类标准选择完整无龋坏的人离体氟斑牙前磨牙共180颗，按轻、中、重度分成3组，每组60颗牙齿。每组再按随机数字表法分为2个小组，每小组30颗牙齿。根据不同分组情况，用金刚砂车针磨除氟斑牙釉质表面0.5 mm，分别用2种粘结剂（全酸蚀粘结剂prime ＆ bond NT、自酸蚀粘结剂SE-BOND）进行粘结，复合树脂Z350加压分层固化，37 ℃蒸馏水中保存24 h。在万能力学性能试验机上测定粘结强度，扫描电镜观察断裂界面。结果全酸蚀粘结剂对轻、中、重度氟斑牙拉伸强度[（7.82 ± 4.20）、（4.79 ± 2.69）、（5.04 ± 2.81）MPa]的影响比较差异有统计学意义（F = 4.610，P 〈 0.05），轻度氟斑牙的拉伸强度最大（P均〈 0.05），中度与重度比较差异无统计学意义（P 〉 0.05）。自酸蚀粘结剂对轻、中、重度氟斑牙拉伸强度的影响比较差异无统计学意义（F = 0.393，P 〉 0.05）。全酸蚀粘结剂对轻度氟斑牙拉伸强度的影响强于自酸蚀粘结剂（t = 2.197，P 〈 0.05）。在扫描电镜下观察，轻度氟斑牙粘结面釉质相对均匀致密，少量晶体排列紊乱，晶体间间隙稍有增宽；重度氟斑牙表面釉质脱落严重，甚至有部分牙本质小管露出，釉质相对疏松且非均匀一致，晶体排列紊乱，晶体间间隙明显增宽，釉柱数量较少；中度氟斑牙与重度氟斑牙的情况基本类似，只是釉质剥离程度较重度氟斑牙略轻。结论①全酸蚀粘结剂对轻度氟斑牙釉质的粘结效果强于自酸蚀粘结剂。②全酸蚀粘结剂对轻度氟斑牙的拉伸强度最大，对中、重度氟斑牙粘结强度无明显差异。

ObjectiveTo compare the bonding strength of different adhesives to the enamel of mild, moderate and severe dental fluorosis with tensile bonding strength, and to provide the experimental foundation for choosing different adhesives for different degrees of dental fluorosis in clinical practice.MethodsAt the Affiliated Hospital of Inner Mongolia Medical University, according to the Dean classification standards, one hundred-eighty extracted caries-free and whole human premolars of dental fluorosis were divided into three groups with mild, moderate and severe degree, 60 teeth in each group. Each group was divided into two subgroups by random number table method, 30 teeth in each subgroup. The emery was used to remove enamel surface 0.5 mm, and then two kinds of bonding adhesives （all-etching adhesive prime ＆ bond NT, self-etching adhesive SE-BOND） were used to bond, pressurized layered composite resin Z350 curing, kept in 37 ℃ distilled water for 24 h. The bonding strength was tested at universal material testing machine, and fracture interface was observated using scanning electron microscope.ResultsAll-etching adhesive had statistical significant influence on the tensile strength of mild, moderate and severe dental fluorosis [（7.82 ± 4.20）, （4.79 ± 2.69）, （5.04 ± 2.81） MPa, F = 4.610, P 〈 0.05], and the tensile strength of mild dental fluorosis was the largest （P 〈 0.05）, the tensile strength between moderate and severe dental fluorosis was not significantly different （P 〉 0.05）. The effect of self-etching adhesive on the tensile strength of mild, moderate and severe dental fluorosis was not statistically significant （F = 0.393, P 〉 0.05）. The effect of all-etching adhesive on the tensile strength of mild dental fluorosis was stronger than that of self-etching adhesive （t = 2.197, P 〈0.05）. Under the scanning electron microscope, the enamel bonding surface of mild dental fluorosis was relatively uniform and compact, with a small amount of crystal disorder, crystal gap slightly widened; the enamel bonding surface of severe dental fluorosis lost seriously enamel, even some of the dentinal tubules exposed, with enamel relatively loose and non uniform, crystal disordered and crystal gap widened significantly, less number of enamel rod. Moderate dental fluorosis was similar to severe dental fluorosis; enamel stripping also occurred under the action of the pulling force but was slighter than severe dental fluorosis enamel.Conclusions①The effect of all-etching adhesive on the tensile strength of mild dental fluorosis is stronger than that of self-etching adhesive. ②The effect of all-etching adhesive on the tensile strength of mild dental fluorosis is the biggest, there is no statistical significant difference between moderate and severe dental fluorosis.