Department of Restorative Dentistry, Faculty of Dentistry, Istanbul University, Fatih, Istanbul, Turkey,
Department of Restorative Dentistry, Faculty of Dentistry, Altinbas University, Istanbul, Turkey.
Am J Dent. 2022 Dec;35(6):308-314.
To evaluate the fracture resistance of endodontically treated premolars restored with CAD-CAM onlay restorations.
60 extracted mandibular first premolars were selected and at first divided into three groups regarding treatment options: MOD onlay with buccal cusp coverage, MOD onlay with buccal cusp coverage + endodontic treatment, MOD onlay with buccal cusp coverage + endodontic treatment + fiber post. Then, all groups were divided into subgroups (n=10) according to the restorative material used: IPS e.max CAD and Lava Ultimate. Each group was submitted to 5,000 thermal cycles, embedded in acrylic resin and secured in a universal testing machine respectively. A compressive load was applied until fracture, at a crosshead speed of 0.5 mm/minute. Statistical significance among each group was analyzed using one-way ANOVA and Bonferroni tests.
Statistically, endodontically treated IPS e.max onlays had numerically the lowest average fracture resistance [753.1 (± 224.9) N/mm² ] among all treatment options. IPS e.max onlays treated with fiber posts had significantly higher resistance than that of endodontically treated IPS e.max CAD group (P= 0.013). Endodontically treated teeth restored with Lava Ultimate onlays [1,381.0 (± 471.7) N/mm²] showed significantly higher averages of fracture resistance than IPS e.max CAD onlays.
CAD-CAM composite (resin nanoceramic) onlays resist greater forces compared to ceramic restorations. Fiber posts could improve the fracture resistance of endodontically treated mandibular premolars following the ceramic CAD-CAM onlays.
评估 CAD-CAM 嵌体修复治疗后上颌前磨牙的抗折能力。
选择 60 颗下颌第一前磨牙，首先根据治疗方案分为三组：颊尖覆盖的 MOD 嵌体、颊尖覆盖的 MOD 嵌体+牙髓治疗、颊尖覆盖的 MOD 嵌体+牙髓治疗+纤维桩。然后，根据使用的修复材料将每组进一步分为亚组（n=10）：IPS e.max CAD 和 Lava Ultimate。每组均进行 5000 次热循环，分别嵌入丙烯酸树脂并固定在万能试验机上。以 0.5mm/min 的十字头速度施加压缩载荷，直至发生断裂。使用单因素方差分析和 Bonferroni 检验对每组间的差异进行统计学分析。
统计学上，所有治疗方案中，牙髓治疗后的 IPS e.max 嵌体的平均抗折力最低[753.1（±224.9）N/mm²]。用纤维桩治疗的 IPS e.max 嵌体的抗折力明显高于牙髓治疗的 IPS e.max CAD 组（P=0.013）。用 Lava Ultimate 嵌体修复的牙髓治疗牙[1381.0（±471.7）N/mm²]的平均抗折力明显高于 IPS e.max CAD 嵌体。
CAD-CAM 复合（树脂纳米陶瓷）嵌体比陶瓷修复体能抵抗更大的力。纤维桩可以提高陶瓷 CAD-CAM 嵌体修复后的牙髓治疗下颌前磨牙的抗折能力。
