title: Effect of software version and parameter settings on the marginal and internal adaptation of crowns fabricated with the CAD/CAM system.
abstract: OBJECTIVE
  This study investigated the marginal and internal adaptation of individual dental crowns fabricated using a CAD/CAM system (Sirona's BlueCam), also evaluating the effect of the software version used, and the specific parameter settings in the adaptation of crowns.
  
  
  METHODS
  Forty digital impressions of a master model previously prepared were acquired using an intraoral scanner and divided into four groups based on the software version and on the spacer settings used. The versions 3.8 and 4.2 of the software were used, and the spacer parameter was set at either 40 μm or 80 μm. The marginal and internal fit of the crowns were measured using the replica technique, which uses a low viscosity silicone material that simulates the thickness of the cement layer. The data were analyzed using a Friedman two-way analysis of variance (ANOVA) and paired t-tests with significance level set at p<0.05.
  
  
  RESULTS
  The two-way ANOVA analysis showed the software version (p<0.05) and the spacer parameter (p<0.05) significantly affected the crown adaptation. The crowns designed with the version 4.2 of the software showed a better fit than those designed with the version 3.8, particularly in the axial wall and in the inner margin. The spacer parameter was more accurately represented in the version 4.2 of the software than in the version 3.8. In addition, the use of the version 4.2 of the software combined with the spacer parameter set at 80 μm showed the least variation. On the other hand, the outer margin was not affected by the variables.
  
  
  CONCLUSIONS
  Compared to the version 3.8 of the software, the version 4.2 can be recommended for the fabrication of well-fitting crown restorations, and for the appropriate regulation of the spacer parameter.
authors.affiliation: Department of Prosthodontics, Ansan Hospital, Korea University, Gyeonggi-do, Republic of Korea.
authors.forename: Ji Suk
authors.initials: JS
authors.lastname: Shim
authors.affiliation: Department of Prosthodontics, Anam Hospital, Korea University, Seoul, Republic of Korea.
authors.forename: Jin Sook
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Prosthodontics, Guro Hospital, Korea University, Seoul, Republic of Korea.
authors.forename: Jeong Yol
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Prosthodontics, Anam Hospital, Korea University, Seoul, Republic of Korea.
authors.forename: Yeon Jo
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Prosthodontics, Guro Hospital, Korea University, Seoul, Republic of Korea.
authors.forename: Sang Wan
authors.initials: SW
authors.lastname: Shin
authors.affiliation: Department of Prosthodontics, Anam Hospital, Korea University, Seoul, Republic of Korea.
authors.forename: Jae Jun
authors.initials: JJ
authors.lastname: Ryu
mesh_terms: D000704:Analysis of Variance; D017076:Computer-Aided Design / Q000592:standards*; D003442:Crowns / Q000592:standards*; D018772:Dental Marginal Adaptation / Q000592:standards*; D017267:Dental Prosthesis Design / Q000592:standards*; D003793:Dental Restoration, Permanent / Q000379:methods; D012015:Reference Standards; D012016:Reference Values; D015203:Reproducibility of Results; D012984:Software / Q000592:standards*; D013499:Surface Properties