Clinical assessment of high-strength all-ceramic crowns

Statement of problem, All-ceramic crowns are being used extensively. Little data are available on their clinical performance. Purpose, This study evaluated thr: clinical performance of In-Ceram (Vita Z ahnfabrik) crowns. Material and methods. Forty-one patients (16 men, 25 nomen; mean age 47.3 y ears, range 18 to 77 years) were examined with a total of SO In-Ceram all-c eramic crowns fabricated at the University of Iowa College of Dentistry fro m 1994 to 1997. The percentage distribution for crowns included: 67% anteri or single crowns, 26% posterior single crowns, 6% anterior implant crowns, and 1% posterior implant crowns. This study documented the integrity of the junction between crown and tooth, color match to adjacent teeth, secondary dental caries, wear of crown and opposing dentition, and visible cracks in the crown. Alpha, Bravo, and Charlie ratings were assigned with a modified USPHS criteria. The patients were also surveyed with respect to oral hygie ne and satisfaction of treatment. Estimations of 4-year success rates and c orresponding confidence intervals were calculated by fitting a. constant ha zard function model with the SAS procedures GENMOD. Results, Marginal integrity for 88% of artificial crowns was rated,Alpha or Bravo. Shade match fur 99% nas Bravo or better. Only 1% of the crowns were carious, and 1 crown exhibited occlusal wear. One premolar crown had a sma ll fracture of veneering porcelain. One molar crown was remade after core f racture. All patients (100%) expressed satisfaction with their crowns. The estimated 4-year success rates (Alpha or Bravo), with 95% confidence interv als in parentheses were calculated as: 83.5% (65.7%-94.6%) for marginal int egrity, 95.8% (82.9%-99.8%) fur shade match, and 95.5% (81.6%-99.7%) for se condary caries, 100% (88%-100%) for wear and 100% (88%-100%) for cracks.