Sendhilnathan Dakshinamurthy, Nayar Sanjna
Department of Prosthodontics, Meenakshi Ammal Dental College, Maduravoyal, Chennai, Tamil Nadu, India.
Indian J Dent Res. 2008 Jan-Mar;19(1):17-21. doi: 10.4103/0970-9290.38926.
To evaluate the effect of post reinforcement, post type and ferrule on the fracture resistance of endodontically treated maxillary central incisors.
Sixty central incisor teeth were selected and grouped into six groups, viz. A, B, C, D, E, and F, each consisting of 10 specimens. Group A specimens were not subjected to any restorative treatment. Group B specimens were endodontically treated and crowned. Specimens of groups C and D were restored with custom cast post and core. Specimens of groups E and F were treated with prefabricated titanium post and composite core. Specimens of groups C and E were restored with porcelain-fused metal (PFM) crown having 2 mm ferrule. Specimens of groups D and F were restored with PFM crown having no ferrule. All the specimens were subjected to load (newton, N) on the lingual surface at a 135 degree angle to the long axis with a universal testing machine until it fractured. The fracture load and mode of fracture of each specimen were noted. One-way analysis of variance with Tukey honestly significant difference procedure was employed to identify the significant difference among the groups at 5% level (P < 0.05).
There were significant differences among the six groups studied (P < 0.0001). The highest fracture strength was recorded with specimen of group C (1376.7 N). There were significant differences between groups A and D versus groups B, E, and F. There were no significant differences between groups B, E, and F. Cervical root fracture was the predominant mode of failure in all the groups except group A.
The results showed that endodontically treated teeth restored with custom cast post core were as strong as the untreated group. Teeth restored with custom cast post core were better resistant to fracture than teeth restored with prefabricated titanium post and composite core. Ferrule is more important in custom cast post core than in prefabricated post and composite core.
评估桩核修复、桩的类型及箍对经根管治疗的上颌中切牙抗折性能的影响。
选取60颗中切牙,分为六组,即A、B、C、D、E和F组,每组10个样本。A组样本未进行任何修复治疗。B组样本经根管治疗后进行全冠修复。C组和D组样本用定制铸造桩核修复。E组和F组样本用预制钛桩和复合树脂核治疗。C组和E组样本用有2mm箍的烤瓷熔附金属(PFM)全冠修复。D组和F组样本用无箍的PFM全冠修复。所有样本通过万能试验机在舌侧表面与长轴呈135度角施加负荷(牛顿,N),直至其断裂。记录每个样本的断裂负荷和断裂模式。采用单因素方差分析和Tukey真实显著差异检验程序,以确定各组间在5%水平上的显著差异(P < 0.05)。
所研究的六组之间存在显著差异(P < 0.0001)。C组样本的抗折强度最高(1376.7 N)。A组和D组与B组、E组和F组之间存在显著差异。B组、E组和F组之间无显著差异。除A组外,所有组的主要失败模式均为颈部根折。
结果表明,用定制铸造桩核修复的经根管治疗牙齿与未治疗组一样坚固。用定制铸造桩核修复的牙齿比用预制钛桩和复合树脂核修复的牙齿更抗折。箍在定制铸造桩核中比在预制桩和复合树脂核中更重要。