【摘要】 目的:比较3种高嵌体材料修复前磨牙MOD洞型的抗折性能。方法:选取50个健康离体上颌前磨牙,随机分为1个对照组和Ⅰ、Ⅱ、Ⅲ、Ⅳ4个实验组(n=10)。对照组不作任何处理;4个实验组常规根管预备和充填后进行高嵌体MOD洞型预备,其中Ⅰ、Ⅱ、Ⅲ组颊舌尖预备2 mm,Ⅳ组预备1 mm。然后Ⅰ组采用间接复合树脂模块修复,Ⅱ组采用二硅酸锂加强型玻璃陶瓷修复,Ⅲ、Ⅳ组采用氧化锆高嵌体修复。最后用万能材料试验机在负荷1 800 N时检测各组样本的抗折性能,体视显微镜下观察样本折裂的类型。结果:对照组及Ⅰ、Ⅱ、Ⅲ、Ⅳ组抗折力(N)分别为1 135.92±228.61、687.58±107.66、705.41±203.78、1 572.84±243.53和1 012.65±193.80,Ⅲ组与其他各组比,P<0.05;Ⅳ组与对照组相比、Ⅰ组与Ⅱ组相比,P>0.05。Ⅰ、Ⅱ组样本折裂主要为E型,其次为B型;Ⅲ、Ⅳ组样本折裂主要为B型和D型。结论:对于根管治疗后的前磨牙,用氧化锆高嵌体修复较间接复合树脂、二硅酸锂加强型玻璃陶瓷高嵌体修复具有更高的抗折性。更多还原

【Abstract】 AIM: To compare the fracture resistance and modes of failures of three different aesthetic MOD onlays on endodontically treated premolars. METHODS: 50 sound maxillary premolars were selected,10 untreated teeth were used as the controls. The other 40 premolars were subjected to standardized MOD onlay preparation and root canal treatment and divided into 4 groups( n = 10). Onlays of indirect composite and lithium disilicate ceramic were respectively prepared for the restoration of the MOD cavity of group Ⅰand Ⅱ,onlays of Full Zirconiafor for group Ⅲ andⅣ. In groupⅠ,Ⅱand Ⅲ buccal and palatal cusps were reduced by 2 mm,and in group Ⅳ by 1 mm. All onlays were cemented using Multilink Automix. All the samples of the 5 groups were subjected to fracture resistance test on universal testing machine. The fractured surfaces were observed under stereo-microscope. RESULTS: The fracture resistance( N) of group control,Ⅰ,Ⅱ,Ⅲ and Ⅳ was 1 135. 92 ± 228. 61,687. 58 ± 107. 66,705. 41 ± 203. 78,1 572. 84 ± 243. 53 and 1 012. 65 ± 193. 80 respectively( group Ⅲ vs the other groups,P < 0. 05; groupⅠ,Ⅱ or Ⅳ vs the control,P > 0. 05). No crack was observed in the restorations of group Ⅲ. The restorations of group Ⅰ and Ⅱshowed mainly type E fracture mode followed by type B; those of group Ⅲ and Ⅳshowed mainly type A fracture mode.CONCLUSION: Full zirconia MOD onlay has higher fracture resistance for endodontically treated premolars than the other MOD systems.更多还原