Ramírez-Sebastià A, Bortolotto T, Roig M, Krejci I
Oper Dent. 2013 Nov-Dec;38(6):663-73. doi: 10.2341/12-208-L. Epub 2013 Apr 9.
To compare the marginal adaptation between ceramic and composite CEREC crowns in endodontically treated teeth restored with endocrowns or with a short or a long post.
Forty-eight intact maxillary incisors were used. After endodontic treatment, the crowns were sectioned 2 mm coronally to the cemento-enamel junction, which provided a ferrule of 2 mm. The prepared teeth were divided randomly into six groups (n=8). Group 1 was restored with a large fiberglass post, composite core, and ceramic full-coverage computer-aided design/computer-assisted manufacturing (CAD-CAM) crown. Group 2 was restored with a short fiberglass post, composite core, and ceramic full-coverage CAD-CAM crown. Group 3 was restored with a large fiberglass post, composite core, and composite full-coverage CAD-CAM crown (LPCpr). Group 4 was restored with a short fiberglass post, composite core, and composite full-coverage CAD-CAM crown (SPCpr). Groups 5 and 6 were restored with ceramic and composite CEREC machined endocrowns, respectively (EndoCer and EndoCpr). The restored teeth were loaded thermomechanically in a computer-controlled chewing machine. Impressions of each restoration were made in a polyvinylsiloxane material before and after loading. Gold-coated epoxy replicas were prepared for scanning electron microscopy examination at 200× magnification.
Loading had a statistically significant effect (p<0.05) on the percentage of "continuous margin" in all groups. The LPCpr, SPCpr, and EndoCpr groups showed the highest percentage of continuous margin initially and after loading. The effect of the different post lengths on marginal adaptation was not significant (p>0.05).
CAD-CAM crowns fabricated from millable composite resin blocks (Paradigm MZ100) offer a superior option to all-ceramic crowns (IPS Empress CAD).
比较在采用桩核冠或短桩或长桩修复的根管治疗牙齿中，陶瓷和复合树脂CEREC全冠的边缘适合性。
使用48颗完整的上颌切牙。根管治疗后，在牙骨质-釉质界冠方2mm处截冠，形成2mm的箍。将预备好的牙齿随机分为六组（n = 8）。第1组用大玻璃纤维桩、复合树脂核和陶瓷全冠计算机辅助设计/计算机辅助制造（CAD-CAM）全冠修复。第2组用短玻璃纤维桩、复合树脂核和陶瓷全冠CAD-CAM全冠修复。第3组用大玻璃纤维桩、复合树脂核和复合树脂全冠CAD-CAM全冠（LPCpr）修复。第4组用短玻璃纤维桩、复合树脂核和复合树脂全冠CAD-CAM全冠（SPCpr）修复。第5组和第6组分别用陶瓷和复合树脂CEREC切削桩核冠修复（EndoCer和EndoCpr）。修复后的牙齿在计算机控制的咀嚼机中进行热机械加载。在加载前后，用聚乙烯硅氧烷材料对每个修复体取模。制备镀金环氧树脂复制品，用于200倍放大的扫描电子显微镜检查。
加载对所有组的“连续边缘”百分比有统计学显著影响（p<0.05）。LPCpr、SPCpr和EndoCpr组在初始和加载后显示出最高的连续边缘百分比。不同桩长度对边缘适合性的影响不显著（p>0.05）。
由可切削复合树脂块（Paradigm MZ100）制作的CAD-CAM全冠比全瓷冠（IPS Empress CAD）提供了更好的选择。
