中文摘要：

目的探讨牙体Ⅱ类洞用树脂或玻璃离子材料充填时，使用牙科红蜡片成型预防悬突形成的效果。方法①选择标准牙模型4个牙位，每个牙位5颗模型牙，共20颗模型牙制备Ⅱ类洞，每颗牙分别按4种方法充填，A、B组为实验组，使用蜡成型即将红蜡片制成蜡楔子塞入牙间隙，制备成假壁，充填相应材料；C、D组为对照组，使用成形片；A、C组用玻璃离子充填，B、D组用复合树脂充填；检测悬突发生情况，并测量悬突高度。②从门诊患者中选择需作Ⅱ类充填治疗的30名患者35颗患牙，用蜡成型做光固化树脂或玻璃离子充填；术后探针探查、拍摄X线片。结果①实验研究中，蜡成型组悬突的发生率和形成悬突的高度均显著小于成形片组。②临床研究中，充填后探针探查，充填体和窝洞边缘连接光滑无台阶感；X线片显示，充填体与牙齿外形轮廓光滑连续。结论Ⅱ类洞树脂类或玻璃离子类材料充填修复过程中，应用牙科红蜡片成型可有效防止悬突的发生，效果优于传统金属成型系统。

英文摘要：

Objective To observe the effects of using base plate wax as matrix for prevention of overhanging in Class Ⅱ composite resin or glass-ionomer restoration. Methods （1）Class Ⅱ cavities were prepared in 20 standard teeth. Each cavity was filled for four times with different materials and matrices （ A, B groups were performed with wax as matrices-A piece of base plate wax was placed in interdental space as a wedge to form a false wall. C, D groups were performed with metallic matrices as control groups. A, C groups were filled with glass-ionomer cement while B, D groups with composite resin）. After filling was completed, the incidences and heights of overhangings were assessed. （2）35 Class Ⅱ cavities in 30 patients were filled with composite resin or glass-ionomer cement using wax as matrix. The edge of restoration was probed and the X-ray photograph was taken for each tooth after operation. Results （1）In laboratory study, both the incidences and heights of overhangings in wax groups were significantly lower than those in the control groups. （2）In clinical study, no overhangings were probed in all patients. X-ray photographs showed all teeth had original shape. Conclusion Using wax as matrix is superior to conventional metal matrix in preventing overhanging in class Ⅱ restoration with resin or glass-ionomer.