Haridy Mohamed F, Ahmed Hend S, Ahmed Radwa Nagy, Elhusseiny Shaimaa Elsayed
Department of Conservative Dentistry, Faculty of Dentistry, The British University, Al Shorouk City, Egypt.
Department of Conservative Dentistry, Faculty of Dentistry, Cairo University, Cairo, Egypt.
Odontology. 2025 Mar 18. doi: 10.1007/s10266-025-01079-4.
The aim of the study was to evaluate the fracture resistance of maxillary premolars restored by different CAD/CAM blocks with different MOD cavity designs. A total of 56 maxillary premolars were selected and randomly divided into 4 groups. I: intact teeth as a positive control group. Standardized MOD cavities were prepared in the remaining group specimens. II: teeth had MOD cavities but were left unrestored as a negative control group. III: MOD preparations restored with inlays with no cusp reduction. IV: MOD preparations restored with overlays with cusp reduction. Group III and IV were further subdivided into two subgroups according to material used, i.e., either lithium disilicate or composite CAD/CAM blocks. All specimens were subjected to 5000 cycles of thermocycling and then tested for fracture resistance. Failure patterns were also examined. Data were statistically analyzed using Welch one-way ANOVA followed by Games-Howell's post hoc test. The results showed significant differences among the experimental groups (p < 0.001). The highest fracture resistance value was observed in positive control group, followed by overlays restored with lithium disilicate blocks. This was followed by overlays restored with composite blocks, then inlays restored by lithium disilicate blocks, inlays restored with composite blocks, while the lowest fracture resistance value was found in negative control group. Regarding failure modes, there was a significant difference between different groups (p < 0.001). The conclusion was that fracture resistance of maxillary premolars restored by CAD/CAM inlays and overlays are greatly affected by the cavity design and material type.
本研究的目的是评估采用不同CAD/CAM嵌体块及不同MOD洞型设计修复的上颌前磨牙的抗折性能。共选取56颗上颌前磨牙并随机分为4组。I组：完整牙齿作为阳性对照组。在其余组的标本上制备标准化的MOD洞型。II组：有MOD洞型但未进行修复的牙齿作为阴性对照组。III组：用未降低牙尖的嵌体修复MOD预备体。IV组：用降低牙尖的高嵌体修复MOD预备体。III组和IV组根据所用材料进一步细分为两个亚组，即二硅酸锂或复合树脂CAD/CAM嵌体块。所有标本均经受5000次热循环，然后测试其抗折性能。还检查了失败模式。数据采用Welch单因素方差分析，随后进行Games-Howell事后检验进行统计学分析。结果显示各实验组之间存在显著差异（p < 0.001）。阳性对照组观察到最高的抗折性能值，其次是用二硅酸锂嵌体块修复的高嵌体。接着是用复合树脂嵌体块修复的高嵌体，然后是用二硅酸锂嵌体块修复的嵌体、用复合树脂嵌体块修复的嵌体，而阴性对照组的抗折性能值最低。关于失败模式，不同组之间存在显著差异（p < 0.001）。结论是CAD/CAM嵌体和高嵌体修复的上颌前磨牙的抗折性能受洞型设计和材料类型的影响很大。
