title: Midterm results of a 5-year prospective clinical investigation of extended ceramic veneers.
abstract: OBJECTIVE
  Midterm-evaluation of a prospective 5-year clinical study on long-term performance and success rate of pressed-ceramic veneers with two extended preparation designs.
  
  
  METHODS
  Anterior teeth of 25 patients were restored with 66 extended veneers. Forty-two overlap veneers (OV) (incisal-edge-reduction 0.5-1.5mm, butt-joint) and 24 full veneers (FV) were inserted. Both veneer designs were similar in buccal (0.5mm) and proximal (0.5-0.7mm) chamfer preparation, but differed in palatal extension. Ceramic veneers were fabricated with IPS Empress* and adhesively luted with dual-polymerizing composite Variolink II* (*Ivoclar Vivadent). Clinical reevaluations were performed 6, 12, 25, 39, 45, and 62 months after insertion of the veneers according to the modified USPHS-criteria. Absolute failures were recorded as survival-rate, relative failures demonstrated by Kaplan-Meier success-rate.
  
  
  RESULTS
  After an observation time up to 5 years, survival-rate of full veneers was 100%, of overlap veneers 97.5% due to one severe fracture. Kaplan-Meier-analysis of relative failures resulted in a success-rate of 85% for FV and 72% for OV. Reasons for relative failures were cracks, ceramic-cohesive-fractures, and loss-of-adhesion. No significant differences were found between the two veneer groups. Secondary caries and endodontic complications did not occur. Increased clinical service time resulted in enhanced marginal discoloration and decrease of marginal adaptation.
  
  
  CONCLUSIONS
  Extended pressed-ceramic veneers (both OV and FV) proved to be reliable procedures to restore larger deficits in anterior teeth. Pronounced palatal extension of full veneers was not linked to a higher failure probability. Reliable adhesive bonding, as well as ceramic fatigue and fracture resistance are considered key factors for long-term success of extended-veneer restorations.
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Hospital Freiburg, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: Petra C
authors.initials: PC
authors.lastname: Guess
authors.forename: Christian F J
authors.initials: CF
authors.lastname: Stappert
mesh_terms: D000328:Adult; D000538:Aluminum Silicates / Q000737:chemistry; D003116:Color; D001840:Dental Bonding; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003801:Dental Veneers; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D016019:Survival Analysis; D019231:Tooth Preparation, Prosthodontic / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000538:Aluminum Silicates; C075815:IPS-Empress ceramic; D019279:Resin Cements; D003776:Dental Porcelain; C103502:Variolink