功能路径技术用于计算机辅助设计全冠(牙合)面解剖形态的探讨

Application of functionally generated path technique in computer-aided-design modeling of occlusal surface of full crown

目的在全冠修复体的计算机辅助设计(CAD)过程中引入功能路径技术(FGP),对修复体(牙合)面进行精确调整,旨在获得符合解剖生理要求的修复体(牙合)面形态。方法选择1例左下第一磨牙全冠修复患者,牙体预备后常规制取印模并灌制工作模型,对工作模型进行机械法扫描获取其表面数字信息。在患者口内取得牙尖交错位(ICP)和 FGP 咬合记录,将其放置于工作模型上进行机械法扫描获得表面数字信息。在全冠修复体 CAD 过程中,将 ICP 和 FGP 咬合信息作为约束条件,对修复体(牙合)面的牙尖和窝沟形态进行精确调整,使其符合患者个体的咬合特征,消除(牙合)干扰。结果利用FGP 咬合记录,在 CAD 过程中调整了全冠修复体的(牙合)面解剖形态,使修复体(牙合)面形态符合个体动态咬合的解剖生理要求。结论 FGP 简单实用,可用于全冠修复体 CAD,获得符合动态功能的(牙合)面形态。

Objective To apply the functionally generated path （FGP） technique for modeling the occlusal surface of a computer-aided-design （CAD） posterior full crown to obtain anatomic morphology. Methods A patient with defected left mandibular first molar was employed. After tooth preparation and impression making, the gypsum working cast and die were scanned with a digitized mechanical scanner and the surface data was acquired. The interocclusal records at intercuspal position （ICP） and FGP were made in the patient＇s mouth. These records were placed on the working cast and their surfaces were scanned. In the process of the computer-aided designing full crown, the cusps and fossae of the occlusal surfaces were accurately modified according to the digitized information of ICP and FGP interocclusal records. Results A full crown was designed and the occlusal morphology of the restoration was adapted to dynamic occlusion as well as static occlusion. Conclusions The FGP technique was practical for the CAD of full crown and could avoid potential occlusal interferences with opposing teeth during function.