|1566 Clinical performance of PFM, zirconia, and alumina three-unit posterior prostheses|
R.P. CHRISTENSEN, K.A. ERIKSSON, and B.J. PLOEGER, TRAC Research Foundation, Provo, UT, USA|
OBJECTIVE: Compare clinical performance of metal vs. ceramic frameworks and layered vs. pressed veneer ceramic.
METHODS: 293 three-unit posterior prostheses were placed by 116 dentists. Methods: standardized preparations, resin modified glass ionomer cement, double blinded dentist-patient and commercial laboratory (18 labs, 2 selected by each system's company). Graded in vivo: margin fit, esthetics, retention, gingival health, endodontic need, caries. Graded in vitro (dies; SEM images): breaks, surface, wear on prosthesis and opposing dentition. Statistics: ANOVA and Tukey-Kramer multiple comparisons (p=£0.05).
RESULTS: Year one 99% recall; year two 98%. Frameworks- no metal or zirconia broken by 2 years; 6 alumina broken by 1 year (18%); 9 by 2 years (26%). Alumina significantly worse both years (p=<0.0001). Veneer Ceramics- pressed had significantly fewer defects at 1 & 2 years (both p=<0.0001).
Defects (surface degradation, chips, breaks, cracks, delamination, broken framework) in systems tested:
* Placed 1 year later
CONCLUSION: At two years, zirconia and metal frameworks performed equally well with no breaks, and alumina had 26% breaks, indicating high risk in posterior multi-unit restorations. Pressed veneer ceramics had significantly fewer defects than layered ceramics.
|Seq #157 - Clinical Investigations of Fixed Prosthodontics|
9:00 AM-10:30 AM, Friday, July 4, 2008 Metro Toronto Convention Centre Room 717B