Yadav Priyanka, Sharma Vineet, Paliwal Jyoti, Meena Kamal K, Madaan Rahul, Gurjar Balwant
Prosthodontics, Rajasthan University of Health Sciences (RUHS) College of Dental Sciences, Jaipur, IND.
Dentistry, Rajasthan University of Health Sciences (RUHS) College of Dental Sciences, Jaipur, IND.
Cureus. 2023 Jan 18;15(1):e33940. doi: 10.7759/cureus.33940. eCollection 2023 Jan.
Purpose This in vitro study aimed to compare the marginal fit and internal adaptation of computer-aided designed and computer-aided manufactured (CAD-CAM) zirconia and hybrid ceramic crowns on heavy chamfer and shoulder finish line designs using silicon replica method. Materials and methods Forty die samples were divided into four groups of 10 dies each. Out of 40 diecasts scanned, zirconia crowns were milled on 20 casts (10 prepared with shoulder and 10 prepared with heavy chamfer finish line design), while hybrid ceramic crowns were milled on the rest of the 20 casts. After milling crowns, the silicone replica technique measured the marginal fit and internal adaptation. Results The heavy chamfer finish line design provided a better marginal fit than the shoulder finish line design for zirconia and hybrid ceramic crowns. Hybrid ceramic crowns had a better marginal fit and internal adaptation than zirconia crowns, both at heavy chamfer and shoulder finish line design. The gap at the margin was less than the axial and occlusal walls, and the maximum gap was observed in the occlusal area. In addition, the marginal gap was less than the internal gap, which showed a positive correlation with each other. Conclusion The study concluded that the difference in CAD-CAM materials and finish line designs influences marginal fit and crown restoration's internal adaptation. A heavy chamfer finish line design provides a better marginal fit for zirconia and hybrid ceramic crowns than a shoulder finish line design. Hybrid ceramic crowns have a better marginal fit and internal adaptation than zirconia crowns in heavy chamfer and shoulder finish lines.
目的 本体外研究旨在使用硅橡胶复制法比较计算机辅助设计与计算机辅助制造（CAD-CAM）氧化锆和混合陶瓷全冠在重斜面和肩台边缘线设计上的边缘适合性和内部适合性。
材料与方法 将40个代型样本分为四组，每组10个代型。在扫描的40个铸型中，在20个铸型上铣削氧化锆全冠（10个采用肩台边缘线设计制备，10个采用重斜面边缘线设计制备），而在其余20个铸型上铣削混合陶瓷全冠。铣削全冠后，采用硅橡胶复制技术测量边缘适合性和内部适合性。
结果 对于氧化锆和混合陶瓷全冠，重斜面边缘线设计比重斜面边缘线设计提供了更好的边缘适合性。在重斜面和肩台边缘线设计中，混合陶瓷全冠均比氧化锆全冠具有更好的边缘适合性和内部适合性。边缘处的间隙小于轴壁和咬合壁，最大间隙出现在咬合区域。此外，边缘间隙小于内部间隙，二者呈正相关。
结论 该研究得出结论，CAD-CAM材料和边缘线设计的差异会影响边缘适合性和全冠修复体的内部适合性。重斜面边缘线设计比肩台边缘线设计为氧化锆和混合陶瓷全冠提供了更好的边缘适合性。在重斜面和肩台边缘线设计中，混合陶瓷全冠比氧化锆全冠具有更好的边缘适合性和内部适合性。
