Volume difference in upper central incisor preparation according to the changes of restorative design and marginal location.
김종현 ; 박영범 ; 이근우 ; 김성태
Journal of Korean Academy of Prosthodontics (대한치과보철학회지)
Journal of Korean Academy of Prosthodontics (대한치과보철학회지), Vol.49(02) : 152~160, 2011
PURPOSE: The aim of this study was to evaluate the volumetric change of teeth after preparation for various designs and margin locations through Micro CT analysis (Skyscan 1076: SKYSCAN, Konitch, Belgium). MATERIALS AND METHODS: The 36 artificial teeth were used to determine reduction volume of upper central incisor. According to the restorative design these 36 teeth were divided into 4 groups and according to the marginal location each group was divided into 3 subgroups. The volume of unprepared teeth was obtained by using Micro CT and the volume of prepared teeth was obtained in the same method. The CT scanned images before and after preparation were superimposed. RESULTS: The volume difference was significantly increased as follows: traditional laminate veneer < full laminate veneer < all ceramic crown < metal ceramic crown. One-way ANOVA and Tukey multiple comparison analyses were used to analyze the data in this study. In each group the volume difference was significantly increased as follows: 1 mm above CEJ < CEJ < 1 mm below CEJ (P<.05). The % volume difference of all ceramic crown and metal ceramic crown was 31 - 48% and that of laminate veneer was 14 - 30%. The volume difference of the traditional laminate veneer was 1/3 of that of metal ceramic crown. The full laminate (1 mm below CEJ) and all ceramic crown (1 mm above CEJ) showed a similar volume difference. Metal ceramic crown showed 13.7 % more volume difference than all ceramic crown. CONCLUSION: There exists the difference in volumetric change according to designs of restoration and margin locations of preparation.