Department of Buccofacial Prosthesis, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain.
Int J Oral Maxillofac Implants. 2012 Nov-Dec;27(6):1448-55.
To evaluate the fracture resistance of all-ceramic crowns cemented on titanium and zirconia implant abutments.
Customized implant abutments for maxillary right central incisors made of titanium (Ti) and zirconia (Zr) (n=60, n=30 per group) were fabricated for an internal connection implant system. All-ceramic crowns were fabricated for their corresponding implant abutments using the following systems (n=10 per group): (1) monolithic computer-aided design/computer-assisted manufacture (CAD/CAM) lithium disilicate (MLD); (2) pressed lithium disilicate (PLD); (3) yttrium stabilized tetragonal zirconia polycrystal (YTZP). The frameworks of both PLD and YTZP systems were manually veneered with a fluorapatite-based ceramic. The crowns were adhesively cemented to their implant abutments and loaded to fracture in a universal testing machine (0.5 mm/minute). Data were analyzed using two-way analysis of variance (ANOVA) and Tukey's test (α=0.05).
Both the abutment material (P=.0001) and the ceramic crown system (P=.028) significantly affected the results. Interaction terms were not significant (P=.598). Ti-MLD (558.5±35 N) showed the highest mean fracture resistance among all abutment-crown combinations (340.3±62-495.9±53 N) (P<.05). Both MLD and veneered ceramic systems in combination with Ti abutments (558.5±35-495.9±53 N) presented significantly higher values than with Zr abutments (392.9±55-340.3±62 N) (P<.05). MLD crown system showed significantly higher mean fracture resistance compared to manually veneered ones on both Ti and Zr abutments (P<.05). While Ti-MLD and Ti-PLD abutment-crown combinations failed only in the crowns without abutment fractures, Zr-YTZP combination failed exclusively in the abutment without crown fracture. Zr-MLD and Zr-PLD failed predominantly in both the abutment and the crown. Ti-YTZP showed only implant neck distortion.
The highest fracture resistance was obtained with titanium abutments restored with MLD crowns, but the failure type was more favorable with Ti-YTZP combination.
评估全瓷冠粘结于钛和氧化锆种植体基台的抗折性能。
为内部连接种植体系统定制的上颌右中切牙用钛（Ti）和氧化锆（Zr）（每组 n=60，n=30）制作的定制种植体基台。使用以下系统为其相应的种植体基台制作全瓷冠（每组 n=10）：（1）整体计算机辅助设计/计算机辅助制造（CAD/CAM）二硅酸锂（MLD）；（2）压制二硅酸锂（PLD）；（3）钇稳定四方氧化锆多晶（YTZP）。PLD 和 YTZP 系统的框架均用基于氟磷灰石的陶瓷手工贴面。将冠用粘结剂粘结到种植体基台上，并在万能试验机上以 0.5 毫米/分钟的速度加载至断裂。使用双因素方差分析（ANOVA）和 Tukey 检验（α=0.05）对数据进行分析。
基台材料（P=.0001）和陶瓷冠系统（P=.028）均显著影响结果。交互项不显著（P=.598）。Ti-MLD（558.5±35 N）在所有基台-冠组合中显示出最高的平均抗折强度（340.3±62-495.9±53 N）（P<.05）。Ti 基台结合 MLD 和贴面陶瓷系统（558.5±35-495.9±53 N）的数值显著高于 Zr 基台（392.9±55-340.3±62 N）（P<.05）。MLD 冠系统在 Ti 和 Zr 基台上的平均抗折强度均显著高于手动贴面系统（P<.05）。Ti-MLD 和 Ti-PLD 基台-冠组合仅在冠无基台骨折时发生失效，而 Zr-YTZP 组合仅在基台无冠骨折时发生失效。Zr-MLD 和 Zr-PLD 主要发生在基台和冠上。Ti-YTZP 仅表现为种植体颈部变形。
用 MLD 冠修复的钛基台获得了最高的抗折强度，但 Ti-YTZP 组合的失效类型更有利。
