title: [Clinical evaluation of two tooth preparation methods of metal-porcelain restoration].
abstract: OBJECTIVE
  To evaluate the clinical performance of the two configurations of gingival margin preparation of tooth.
  
  
  METHODS
  The cases in this study were divided into two groups according to different tooth defects. Each group consisted of 40 cases. One group's gingival margin configuration was 90 degree shoulder, the other was under-gingival non-shoulder. The clinical performance of these restorations was followed up for 1 year and 2 years. The evaluators examined the restorations for plaque index, gingival index, marginal discolor and marginal fit.
  
  
  RESULTS
  There was no significant difference in the evaluators between the two groups.
  
  
  CONCLUSIONS
  The under-gingival non-shoulder margin configuration of porcelain fused to metal should be used for clinical application compared with the 90 degree shoulder one in certain circumstance.
authors.affiliation: Dept. of Prosthodontics, School of Stomatology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Yu-ling
authors.initials: YL
authors.lastname: Li
authors.forename: Qing-tao
authors.initials: QT
authors.lastname: Wang
authors.forename: Li-chong
authors.initials: LC
authors.lastname: Lan
authors.forename: Chun-hua
authors.initials: CH
authors.lastname: Lin
mesh_terms: D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D006801:Humans; D016876:Metal Ceramic Alloys; D019231:Tooth Preparation, Prosthodontic / Q000379:methods*
chemical_list: D016876:Metal Ceramic Alloys; D003776:Dental Porcelain