Ramírez-Sebastià Anaïs, Bortolotto Tissiana, Cattani-Lorente Maria, Giner Lluis, Roig Miguel, Krejci Ivo
Department of Endodontic and Restorative Dentistry, School of Dentistry, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Barcelona, Spain,
Clin Oral Investig. 2014;18(2):545-54. doi: 10.1007/s00784-013-0978-3. Epub 2013 Apr 20.
This study aims to evaluate the fracture resistance of endodontically treated anterior teeth restored with crowns made of composite or ceramic and retained without the use of a post (endocrowns) or with posts of 5 mm (short) and 10 mm in length (long).
Forty-eight intact maxillary incisors were selected for the study. After endodontic treatment, the crowns were sectioned 2 mm coronally to the cementoenamel junction provided with a ferrule of 2 mm. The roots were randomly divided into six groups (n = 8) according to the post length and type of coronary restoration. The crowns were fabricated with the chairside economical restoration of esthetic ceramics system. Group 1 was restored with a 10-mm glass fiber post, composite core, and a full-coverage ceramic crown (LPCer); group 2, with a 5-mm glass fiber post, composite core, and a full-coverage ceramic crown (SPCer); group 3, with a 10-mm glass fiber post, composite core, and a full-coverage composite crown (LPCpr); group 4, with a 5-mm glass fiber post, composite core, and a full-coverage composite crown (SPCpr); and groups 5 (EndoCer) and 6 (EndoCpr) were restored with ceramic and composite endocrowns, respectively. The teeth were then thermomechanically loaded in a chewing machine. After fatigue, the specimens were loaded to fracture. Data were analyzed with ANOVA and chi-square test. Mode of failure was defined as repairable or non-repairable.
Presence of post, post length, and crown material had no significant effect on the fracture resistance. Groups restored with endocrowns presented a higher number of repairable fractures in respect to the other groups.
Presence of a post had no effect on the restorations' fracture strength.
Although this in vitro study has some limitations in respect to its clinical relevance, the restoration of largely destroyed anterior teeth with the use of an endocrown or a short glass fiber post might have advantages over a large glass fiber post.
本研究旨在评估经根管治疗的前牙，采用复合树脂或陶瓷制成的全冠修复，不使用桩（根管内冠）或使用长度为5mm（短桩）和10mm（长桩）的桩时的抗折性能。
选择48颗完整的上颌切牙进行研究。根管治疗后，在牙骨质牙釉质界上方2mm处截冠，形成2mm的箍。根据桩的长度和冠修复类型，将牙根随机分为六组（n = 8）。全冠采用椅旁美学陶瓷经济型修复系统制作。第1组用10mm玻璃纤维桩、复合树脂核和全瓷冠修复（LPCer）；第2组用5mm玻璃纤维桩、复合树脂核和全瓷冠修复（SPCer）；第3组用10mm玻璃纤维桩、复合树脂核和全复合树脂冠修复（LPCpr）；第4组用5mm玻璃纤维桩、复合树脂核和全复合树脂冠修复（SPCpr）；第5组（EndoCer）和第6组（EndoCpr）分别用陶瓷和复合树脂根管内冠修复。然后在咀嚼机上对牙齿进行热机械加载。疲劳后，对标本进行加载直至折断。数据采用方差分析和卡方检验进行分析。失败模式分为可修复或不可修复。
桩的存在、桩的长度和冠材料对抗折性能无显著影响。与其他组相比，采用根管内冠修复的组出现可修复骨折的数量更多。
桩的存在对修复体的抗折强度没有影响。
尽管这项体外研究在临床相关性方面存在一些局限性，但对于大部分牙体组织已破坏的前牙，使用根管内冠或短玻璃纤维桩进行修复可能比使用长玻璃纤维桩更具优势。
