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 configurationwas 90°shoulder, the otherwas under-gingival non-shoulder. The clinical perfor- mance of these restorationswas followed up for 1 year and 2 years. The evaluators examined the restorations for plaque index, gin- gival index, marginal discolor and marginal fit.Results There was no significant difference in the evaluators between the two groups.Conclusion The under-gingival non-shouldermargin configuration of porcelain fused to mental should be used for clinical application compared with the 90°shoulder one in certain circumstance.
