Original Articals
Study on functional occlusal morphology by using three-dimensional printed diagnostic crown and functional generated path technology
Jiang Ting, Cheng Mingxuan, Sun Yuchun, Jia Lu
Published 2020-01-09
Cite as Chin J Stomatol, 2020, 55(1): 9-14. DOI: 10.3760/cma.j.issn.1002-0098.2020.01.003
Abstract
ObjectiveTo establish the functional occlusal morphology of fixed prostheses by using functional generated path (FGP) technology on a three-dimensional-printed diagnostic crown in order to decrease the chance of occlusal adjustment during try-in procedure of the complete crown, and to avoid the risk of occlusal interference after cementation of prosthesis.
MethodsA double-blind clinical trial was performed. Ten subjects (4 males, 6 females) who needed a first molar complete crown restoration were enrolled in Department of Prosthodontics, Peking University School and Hospital of Stomatology from July 2018 to December 2018. The working models with the abutment teeth of the ten participants were scanned to obtain the digital models, then the occlusal surfaces of crown were formed by either FGP technology on a three-dimensional (3D) printed diagnostic crown and then were scanned directly for computer aided design and computer aided manufacture (CAD/CAM) crown fabrication as experiment group, or conventional technology based on database as control group. Then zirconia crowns were fabricated for two groups. During crown try-in of the two groups, preferred crowns of subjects were recorded, the occlusal contact criteria including the occlusal contact area (mm2), the heights of occlusal high spot (mm) before and after the adjustment of crowns were digitally analyzed, and the amount of adjustment (mm and mm3) were calculated on digital models by using a reverse engineering software (Giomagic Sudio & Quality). Differences of values were compared statistically with paired t-test (α=0.05).
ResultsThe amount for occlusal adjustment for crowns in the experiment group [(7.320±4.238) mm3] was statistically less than that in the control group [(20.178±9.650) mm3] (P<0.05), the occlusal contact area of experiment group [(11.430±4.102) mm2] was statistically bigger than that of the control group [(4.808±3.223) mm2] (P<0.05), the heights of occlusal high spots for crowns in the experiment group was (0.043±0.019) mm while it was (0.594±0.201) mm in the control group with statistically significant differences (P<0.05).
ConclusionsThis method could lead to a crown with less adjustment of occlusion, less occlusal high spot and less risk of occlusal interferences.
Key words:
Dental models; Occlusal adjustment; Three-dimensional print; Functional generated path
Contributor Information
Jiang Ting
Department of Prosthodontics, Peking University School and Hospital 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, Beijing 100081, China
Cheng Mingxuan
Department of Prosthodontics, Peking University School and Hospital 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, Beijing 100081, China
Sun Yuchun
Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology &
National Clinical Research Center for Oral Diseases &
National Engineering Laboratory for Digital and Material Technology of Stomatology &
Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health &
Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
Jia Lu
Center of Dental Laboratory Peking University School and Hospital 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, Beijing 100081, China
面形态初探
面形态，探索减少修复体
面调改量以及避免
干扰的临床方法。
面，通过口内FGP法直接获得具有功能接触形态的
面，扫描后制作计算机辅助设计与辅助制作氧化锆全冠修复体；对照组：按照数据库及经验常规设计制作氧化锆全冠修复体。临床试戴后用逆向工程软件（Geomagic Sudio & Quality）对修复体 
面调改前后的咬合接触位置及面积、咬合接触程度、
面调改高度和体积等指标进行数字化定量分析，并对两组数据进行配对t检验。
面形态。试验组修复体
面调改体积[（7.320±4.238）mm3]显著小于对照组[（20.178±9.650）mm3]（P<0.05）；调改前试验组咬合高点高度[（0.043±0.019）mm]显著低于对照组[（0.594±0.201）mm]（P<0.05），咬合接触面积[（11.430±4.102）mm2]显著大于对照组[（4.808±3.223）mm2]（P<0.05）。
面的个性化功能接触形态，可比常规方法显著减少修复体调改量并降低咬合高点。
干扰可诱发
创伤及颞下颌关节和咀嚼肌功能紊乱，因此，修复体试戴时的咬合调改仍不可避免。为形成符合人体运动轨迹、无
干扰的修复体，多年来学界对下颌运动规律和运动轨迹模拟装置进行了大量研究，包括各种复杂的下颌运动描记仪、可调式
架、数字化
架等，均是在试戴修复体前进行预先调
，减少椅旁调改时间。人体口腔优于任何形式的
架，牙齿
面的尖、嵴、斜面、窝形态均符合下颌运动及咀嚼运动终末期轨迹。功能引导路径（functional generated path，FGP）技术即通过患者实际的下颌运动，在口内用对颌牙尖雕刻修复体
面的个性化功能形态，运用静态材料记录动态运动，避免咬合高点和
干扰，但该技术并未在临床普及应用。
