Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology & Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health, PR China.
Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, PR China.
J Prosthodont. 2023 Jun;32(5):439-444. doi: 10.1111/jopr.13574. Epub 2022 Aug 10.
To compare the accuracy of occlusal wear facet morphology designed using different bite registration methods for mandibular first molar crowns.
The posterior teeth and intraoral intercuspal occlusions of 12 participants were scanned. The abutment shape of the mandibular first molars for complete crowns was virtually designed, and the anatomic coping design method was used to design crowns. In the anatomic coping design, digital wax patterns were constructed by elevating the wear facets on the original surface of the first molars and then adjusting the facets with 2 types of virtual occlusions determined by buccal bite registration (BBR) or segmented tooth registration (STR) methods, where the displacement of teeth under bite force was considered (STR) or not (BBR). The occlusal distance between the original wear facets and the antagonists as well as 3D deviations between the facets on the designed crowns and on the surfaces of the original teeth were measured. Paired-samples t-test was used to analyze the results (α = 0.05).
Regarding occlusal distance, the mean 3D deviation and the root mean square (RMS) values of BBR were greater than those of the STR groups (p < 0.001 and p = 0.008). The mean 3D deviations of the crowns of the BBR and STR groups were 0.19 ±0.04 mm and 0.14 ±0.06 mm, respectively and the RMS values were 0.22 ±0.03 mm and 0.18 ±0.04 mm (p < 0.001), respectively.
The morphology of occlusal wear facets of mandibular first molar crowns designed with the occlusion constructed using the segmented tooth registration method are more coincident with the original morphology.
比较使用不同咬合记录方法设计下颌第一磨牙冠牙合面磨损形态的准确性。
扫描了 12 名参与者的后牙和牙尖交错位。虚拟设计下颌第一磨牙完整冠的基牙形状，使用解剖式牙合面设计方法设计牙冠。在解剖式牙合面设计中，通过抬高第一磨牙原始表面的磨损面来构建数字蜡型，然后使用颊侧咬合记录（BBR）或分段牙注册（STR）方法确定的 2 种虚拟咬合来调整牙合面，考虑（STR）或不考虑（BBR）咬合力下牙齿的位移。测量原始磨损面与对颌牙之间的牙合距离以及设计牙冠上的牙合面与原始牙表面之间的三维偏差。采用配对样本 t 检验进行分析（α=0.05）。
关于牙合距离，BBR 的平均三维偏差和均方根（RMS）值大于 STR 组（p<0.001 和 p=0.008）。BBR 和 STR 组牙冠的平均三维偏差分别为 0.19±0.04mm 和 0.14±0.06mm，RMS 值分别为 0.22±0.03mm 和 0.18±0.04mm（p<0.001）。
使用分段牙注册方法构建的咬合设计的下颌第一磨牙冠牙合面磨损形态与原始形态更吻合。
