title: Effects of Implant Angulation and Impression Coping Type on the Dimensional Accuracy of Impressions.
abstract: OBJECTIVE
  To analyze the accuracy of impressions in relation to implant angulation and type of impression coping.
  
  
  METHODS
  Three metal master models with 2 implants of 3 different angulations (parallel, mesiodistal, and buccolingual) were fabricated. Nine groups of experimental models were fabricated to duplicate the 3 master models using 3 types of impression copings: transfer, pick-up, and hybrid. The distance between the analogs for each model was measured using a video measuring system. The influence of angulation and type of impression coping was analyzed by a two-way ANOVA (P < 0.05).
  
  
  RESULTS
  There were significant differences in error rates in relation to implant angulation and type of impression coping (P < 0.05). Impressions of buccolingually divergent implants with transfer copings showed statistically higher error rates than other groups (P < 0.05).
  
  
  CONCLUSIONS
  Buccolingual divergence can be a variable that influences the impression accuracy of transfer copings compared with pick-up and hybrid copings. Hybrid copings demonstrate reasonable reproducibility similar to that of pick-up copings.
authors.affiliation: *Affiliated Professor, Department of Prosthodontics, Faculty of Dentistry, Korea University Ansan Hospital, Seoul, Korea. †Full-Time Professor, Department of Prosthodontics, Faculty of Dentistry, Korea University Anam Hospital, Seoul, Korea. ‡Full-Time Professor, Department of Prosthodontics, Faculty of Dentistry, Korea University Guro Hospital, Seoul, Korea. §Affiliated Professor, Department of Advanced Prosthodontics, Faculty of Dentistry, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Ji Suk
authors.initials: JS
authors.lastname: Shim
authors.forename: Jae Jun
authors.initials: JJ
authors.lastname: Ryu
authors.forename: Sang Wan
authors.initials: SW
authors.lastname: Shin
authors.forename: Jeong Yol
authors.initials: JY
authors.lastname: Lee
mesh_terms: D059605:Dental Implant-Abutment Design / Q000379:methods; D015921:Dental Implants; D003761:Dental Impression Technique; D017267:Dental Prosthesis Design; D006801:Humans
chemical_list: D015921:Dental Implants