title: The influence of finish line curvature on the marginal gap width of ceramic copings.
abstract: BACKGROUND
  As a result of natural tooth anatomy or gingival recession, anterior teeth are more likely to present increased abutment finish line curvature.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the influence of the curvature of the finish line on the marginal gap widths of ceramic copings.
  
  
  METHODS
  An ivorine maxillary central incisor was prepared for 3 different abutment finish line curvatures (1, 3, and 5 mm). Thirty-six copings were fabricated for each of these curvatures by using Cercon, IPS e.max, and Lava systems. The marginal gap width was measured by using a stereomicroscope, and the data were subsequently analyzed by means of a 2-way ANOVA and a 1-way ANOVA (α=.05).
  
  
  RESULTS
  A significantly higher mean marginal gap width was found for the 5-mm curvature group (Cercon, 76.59 ±23.01 µm; IPS e.max, 106.44 ±18.48 µm; Lava, 128.34 ±20.79 µm) than for both the 3-mm curvature group (Cercon, 60.18 ±9.74 µm; IPS e.max, 81.79 ±16.20 µm; Lava, 99.19 ±15.32 µm) and the 1-mm curvature group (Cercon, 38.3 ±6.85 µm; IPS e.max, 52.22 ±10.66 µm; Lava, 69.99 ±6.77 µm).
  
  
  CONCLUSIONS
  The greater the finish line curvature, the wider the marginal gap widths for the 3 ceramic systems.
authors.affiliation: Esthetic Restorative and Implant Dentistry, Faculty of Dentistry, School of Dentistry, Chulalongkorn University, Bangkok 10330, Thailand. chutimayyy@hotmail.com
authors.forename: Chutima
authors.initials: C
authors.lastname: Asavapanumas
authors.forename: Chalermpol
authors.initials: C
authors.lastname: Leevailoj
mesh_terms: D017076:Computer-Aided Design; D003442:Crowns; D000044:Dental Abutments; D003760:Dental Impression Materials / Q000737:chemistry; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D006801:Humans; D007180:Incisor; D012117:Resins, Synthetic / Q000737:chemistry; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic / Q000379:methods; D014800:Vitallium / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D003760:Dental Impression Materials; C508050:IPS e.max Press; C022821:Impregum; D012117:Resins, Synthetic; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D014800:Vitallium; D015019:Yttrium; D015040:Zirconium