口内扫描数字化印模技术在磨牙区牙体达龈下缺损全冠修复中的应用

Application of intraoral scanning digital impression technology in full crown restoration of subgingival defect in molar area

目的:探索口内扫描数字化印模(IDI)技术在磨牙区牙体缺损达龈下全冠修复的效果。方法:选择2020年9月~2021年10月因磨牙区牙体缺损达牙龈下患者16例(16颗患牙)。完成牙体预备后,采用IDI获取龈上基牙数据,再用改良法双相二次印模技术获得包括龈下缺损牙体组织的基牙石膏模型;通过扫描石膏模型将龈下牙体组织数据与IDI获得的数字模型数据拟合,获取完整的基牙数据。CAD/CAM完成全解剖氧化锆冠的设计与制作。评价修复效果,并于治疗1个月、6个月后复查基牙牙菌斑指数(PLI)和牙龈指数(GI)。结果:16颗全冠边缘完整性、就位支点、边缘台阶评级、咬合评级均为临床接受等级。冠边缘适合性检查颊侧(92.36±10.32)μm、舌/腭侧(106±12.35)μm、近中(85±8.35)μm、远中(88±9.45)μm。修复后1个月患牙PLI和GI分别为(0.78±0.43)分和(0.82±0.53)分;修复后6个月PLI和GI分别为(0.58±0.40)分和(0.72±0.46)分。结论:通过改良IDI技术,实现磨牙区舌/腭侧牙体缺损达龈下冠修复,短期修复效果临床接受。

Objective:To explore the effect of intraoral scanning digital impression(IDI)technique in the restoration of molar tooth defect with subgingival full crown.Methods:From September 2020 to October 2021,16 patients with subgingival defects in molar area were selected.After preparation of the affected teeth, IDI was used to obtain the data of the upper gingival abutment, and then the superanhydrite model of the abutment including the subgingival defect tooth tissue was obtained by the improved biphasic secondary impression technology.The data of subgingival tooth tissue was fitted with the data of digital model obtained by IDI,and the complete abutment data was obtained.The whole anatomical zirconia crown was designed and manufactured by CAD/CAM system.The restoration effect was evaluated, and the plaque index(PLI)and gingival index(GI)of abutment teeth were reexamined after 1 month and 6 months of restoration.Results:The marginal integrity, emplacement fulcrum, marginal step rating and occlusion rating of 16 crowns were all clinically accepted grades.The results of coronal marginal fitness were(92.36±10.32)μm on buccal side,(106±12.35)μm on tongue(palate)side,(85±8.35)μm on mesial side and(88±9.45)μm on distal side.One month after restoration, PLI and GI were(0.78±0.43)and(0.82±0.53),respectively, that were(0.58±0.40)and(0.72±0.46)at 6 months after restoration.Conclusion:Through improved IDI technique, the tongue(palate)tooth defect in molar area can be restored to subgingival crown, and the short-term restoration effect is clinically accepted.