Premium
Influence of misfit on the occurrence of veneering porcelain fractures (chipping) in implant‐supported metal‐ceramic fixed dental prostheses: an in vitro pilot trial
Author(s) -
Löfgren Nils,
Larsson Christel,
Mattheos Nikos,
Janda Martin
Publication year - 2017
Publication title -
clinical oral implants research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.407
H-Index - 161
eISSN - 1600-0501
pISSN - 0905-7161
DOI - 10.1111/clr.12997
Subject(s) - veneer , dentistry , abutment , implant , dental abutments , dental prosthesis , significant difference , fixed prosthodontics , orthodontics , dental porcelain , materials science , ceramic , medicine , composite material , surgery , engineering , civil engineering
Objective Technical complications such as veneer fractures are more common in implant‐supported than tooth‐supported restorations. The underlying causes have not been fully identified. The aim of this study was to evaluate whether misfit between the restoration and the implant may affect the risk of veneer fractures. Materials and methods Twenty standardized five‐unit implant‐supported metal‐ceramic fixed dental prostheses ( FDP )s were manufactured and fixed in acrylic blocks. The test group consisted of ten FDP s fixed with a 150‐μm misfit at the distal abutment. The remaining ten FDP s were fixed without misfit and acted as a control group. All FDPS underwent cyclic loading for a total of 100,000 cycles at 30‐300 N. The FDP s were checked for cracks or chip‐off fractures regularly. After cyclic load, the retorque value of all abutment screws was checked. Results Cracks within the veneering porcelain were noted in nine FDP s in the test group and one FDP in the control group. This difference was statistically significant ( P < 0.001). Fractures of the veneering porcelain occurred in three FDP s in the test group. No fractures occurred in the control group. This difference was not statistically significant. There were no significant differences in retorque values neither between the groups nor between different abutment positions in the FDPs . Conclusions Within the limitations of this in vitro pilot trial, it is suggested that misfit between a restoration and the supporting implant may increase the risk of cracking and/or chipping of the veneering porcelain for metal‐ceramic FDP s.