Department of Dental Sciences, Centre of Heath Sciences, Univ. Federal de Santa Catarina, Florianópolis, SC, Brazil.
Deparment of Mechanical Engineering, Biomechanics Engineering Laboratory, University Hospital, Univ. Federal de Santa Catarina, Florianópolis, SC, Brazil.
Braz Oral Res. 2014;28. doi: 10.1590/1807-3107bor-2014.vol28.0011. Epub 2014 Jun 11.
The purpose of this study was to evaluate the influence of buccal and lingual wall thickness on the fatigue resistance of molars restored with CAD/CAM ceramic inlays. Forty human third molars were selected and divided into 4 groups, according to the remaining surrounding wall thickness chosen for inlay preparation (n=10): G1, 2.0 mm; G2, 1.5 mm; G3, 1.0 mm; G4, 0.5 mm. All inlays were made from feldspathic ceramic blocks by a CAD/CAM system, and cemented adhesively. After 1 week stored in distilled water at 37 °C, the specimens were subjected to fatigue testing under the following protocol: 5Hz; pre-load of 200 N for 5,000 cycles, followed by increasing loads of 400, 600, 800, 1000, 1200 and 1400 N for 30,000 cycles each. The specimens were cycled until failure or completion of 185,000 cycles. The survival rate of the groups was compared using the Kaplan-Meier survival curves (p>0.05). All specimens withstood the fatigue protocol (185,000 cycles), representing a 100% survival rate. The Kaplan-Meier survival curves showed no difference between groups. It can be concluded that the remaining tooth wall thickness did not influence the fatigue resistance of molars restored with CAD/CAM ceramic inlays.
本研究旨在评估颊舌壁厚度对 CAD/CAM 陶瓷嵌体修复磨牙疲劳抗力的影响。选择 40 个人类第三磨牙，根据嵌体预备时选择的剩余周围壁厚度分为 4 组（n=10）：G1，2.0mm；G2，1.5mm；G3，1.0mm；G4，0.5mm。所有嵌体均由 CAD/CAM 系统从长石陶瓷块制成，并通过胶结剂黏合。在 37°C 的蒸馏水中储存 1 周后，根据以下方案对标本进行疲劳测试：5Hz；5000 次循环的预载 200N，随后每次循环增加 400、600、800、1000、1200 和 1400N，持续 30000 次。标本循环至失效或完成 185000 次循环。使用 Kaplan-Meier 生存曲线（p>0.05）比较各组的存活率。所有标本均经受住了疲劳方案（185000 次循环），存活率为 100%。Kaplan-Meier 生存曲线显示各组之间无差异。可以得出结论，剩余牙壁厚度不会影响 CAD/CAM 陶瓷嵌体修复磨牙的疲劳抗力。
