A 10-year longitudinal study of fixed prosthodontics: clinical characteristics and outcome of single-unit metal-ceramic crowns.
OBJECTIVE
The purpose of this study was to report on the clinical characteristics and outcome of 688 single-unit metal-ceramic crowns placed in a specialist prosthodontic practice between January 1984 and December 1992.


METHODS
Clinical and laboratory techniques were standardized and patients were recalled by the author between June and December of 1993. The outcome of all crowns was allocated to one of 6 fields in this assessment period.


RESULTS
Clinical review examination by the author covered 87% of the crowns. Of these, 52% had been in service for 5 to 10 years and 48% for less than 5 years but more than 1 year; 67% of the crowns were placed on vital teeth and 94% were given a "good prognosis" rating at examination. The repair and failure rates of crowns in the 5 to 10 years in clinical service group were both 3%. Crowns on nonvital teeth in the same grouping had a significantly greater failure rate (5%) than crowns on vital teeth (1%), and anterior teeth had a significantly greater retreatment rate than posterior teeth. Retreatment for all 25 crowns occurred within 66 months after cementation. Tooth fracture accounted for 56% of retreatments, while caries and loss of retention accounted for only 24% of retreatments; 2% of initially vital teeth were endodontically treated during the survey period.


CONCLUSIONS
Single-unit metal-ceramic crowns have a high expectancy of exceeding 10 years of clinical service when the described clinical and laboratory protocol is applied.
Walton
T R
TR
University of Sydney, Faculty of Dentistry, Australia. twalton@mail.usyd.edu.au
D000328:Adult; D016009:Chi-Square Distribution; D003442:Crowns; D018772:Dental Marginal Adaptation; D017267:Dental Prosthesis Design; D017269:Dental Prosthesis Repair / Q000706:statistics & numerical data; D017268:Dental Prosthesis Retention; D019232:Dental Restoration Failure; D005260:Female; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys; D008875:Middle Aged; D019233:Retreatment; D016019:Survival Analysis; D019231:Tooth Preparation, Prosthodontic; D016896:Treatment Outcome
D016876:Metal Ceramic Alloys