Galvano- vs. metal-ceramic crowns: up to 5-year results of a randomised split-mouth study

Full-crown restorations made by galvano forming may be considered as highly biocompatible, stable and aesthetic restorations. Therefore, they represent an alternative to conventional metal-ceramic crowns (MC), which might be associated with an allergic or toxic reaction due to metal oxides. In current literature, there are few clinical reports available, but no comparative clinical evaluation of these two systems. Thus, the purpose of this clinical observation was to compare the long-term success of galvano-formed crowns (GC) and MC and to evaluate post-operative complications. The working hypothesis was that there was no difference in clinical success between crowns based on galvano-forming procedure or conventional metal-ceramic crowns. A prospective, randomised, double-blinded clinical trial was conducted. 48 GC and 48 MC were placed in 48 periodontal healthy patients (male = 24; female = 24) in a split-mouth design. Prosthetic parameters as technical, biological and endodontic problems were recorded. Restoration survival--MC vs. GC--was compared using a non-parametric Chi-square test by McNemar at 5% level of significance. The crown restorations were re-evaluated after an observation time of 13 to 64 months (mean = 40.5; SD = 11 months). 45 GC and 45 MC (94%) were in situ without any complications. No significant differences were found between GC and MC. Surface conditions differed only in part. Fractures of the veneering material were observed in one (2%) and two (4%) for MC and GC, respectively. The presented data indicate that GC appears to be a successful alternative to conventional MC systems.