Objective: To use a self-developed, prefabricated cap for making interocclusal records in implant-supported fixed prosthetic treatment, and to evaluate its effect of clinical application and accuracy of transferring intra-oral intercuspal position. Methods: Series of prefabricated caps for occlusal recording of implant-supported fixed prostheses were designed based on the healing abutments, and fabricated with three-dimensional (3D) printing. According to the inclusion and exclusion criteria, 12 partially edentulous patients who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology between November 2020 and September 2021, had lost no fewer than 2 contiguous teeth in distal extension (Kennedy Class Ⅰ or Ⅱ), and had received implant placement 3 months ago were enrolled. Self-control study design was used. Two occlusal records of each included case were obtained by the following 2 methods: for the test group, appropriate prefabricated caps were used; and for the control group, polyvinyl siloxane occlusal record was directly set on the healing abutments. The working casts were mounted on the mechanical articulator using the 2 groups of occlusal records successively. Accuracy of occlusal relationship of the mounted casts was evaluated. Diagnostics test was performed to obtain the sensitivity and positive predictive value, which were determined in photographs by comparing the intra-oral occlusal contact points with those in the mounted casts, point-by-point. Virtual casts were taken by intraoral and extraoral scans in intercuspal position and imported to Geomagic Studio 2014. Then the root mean square values of occlusal clearance space between the upper and lower occlusal surfaces of remaining posterior teeth, and the deviations of the interocclusal position of the occlusal surfaces of the remaining teeth in the mandibular arches when superimposing the maxillary arches of the intraoral and extraoral scans were calculated. As a self-control design, paired t test was used. Results: Twelve participants were enrolled, including 3 men and 9 women aged (52.6±12.1) years, and 36 missing teeth. The prefabricated caps could fit on the healing abutments with good retention and stability. The sensitivity of the test group (0.73±0.14) was significantly better than that of control group (0.63±0.12,P<0.01), with no significant difference in positive predictive value between the 2 groups (P>0.05). The deviations of the interocclusal position of the occlusal surfaces of the remaining teeth were (357.0±140.2) μm for the test group, and (399.4±206.3) μm for the control group, with no significant difference between them (P>0.05). Conclusions: Interocclusal position record based on prefabricated cap in this study for implant-supported fixed prosthetic treatment can improve the consistency between the intra-oral occlusion and the occlusion in dental casts. This technique has good accuracy, clinical convenience and usability.
目的： 评价自主研发的预成咬合记录帽制取种植固定修复咬合记录的临床应用效果及转移咬合关系的精确性。 方法： 基于愈合基台设计系列预成咬合记录帽，光固化三维打印实物。前瞻性收集2020年11月至2021年9月于北京大学口腔医学院·口腔医院修复科就诊、Kennedy Ⅰ类或Ⅱ类牙列缺损拟行种植固定修复的患者12例，需满足不少于2颗后牙连续游离缺失。采用自身对照，对病例同时采用2种方法制取咬合记录：试验组用预成咬合记录帽，对照组用硅橡胶咬合记录材料直接在愈合基台上制取。分别根据两组咬合记录上（牙合）架，评价模型咬合关系精确性。采用诊断试验的方法计算模型咬合接触的灵敏度和阳性预测值，并利用口内扫描、模型扫描获取修复前牙尖交错位咬合关系数据，导入三维逆向工程软件计算上下颌余留后牙（牙合）面间距，以及配准模型扫描与口内扫描的上颌，计算下颌模型余留牙（牙合）面三维偏差值。采用配对t检验进行两组比较。 结果： 纳入男性病例3例、女性9例，年龄（52.6±12.1）岁，缺失牙共36颗。预成咬合记录帽在口内能直接就位，固位、稳定性良好。试验组模型咬合接触的灵敏度（0.73±0.14）显著优于对照组（0.63±0.12，P<0.01），阳性预测值（0.79±0.15）与对照组（0.75±0.10）差异无统计学意义（P>0.05）。试验组和对照组（牙合）面三维偏差值［分别为（357.0±140.2）和（399.4±206.3）μm］差异无统计学意义（P>0.05）。 结论： 用预成咬合记录帽制取种植固定修复咬合记录可提高模型与口内咬合关系的一致性，具备良好的精确性、临床便利性和易用性。.