Axial wall thickness of zirconia abutment in anterior region / 대한치과보철학회지

ABSTRACT

PURPOSE: The purpose of this study was to evaluate the proper axial thickness of zirconia abutment applied to implant in the anterior region. MATERIALS AND METHODS: Zirconia abutments were prepared at different axial wall thickness by processing pre-sintered zirconia blocks via CAD/CAM to obtain equal specimens. The abutments were each produced with a thickness of 0.5 mm (Group 1), 0.8 mm (Group 2), 1.2 mm (Group 3), or 1.5 mm (Group 4). The implant used in this study was a external connection type one (US, Osstem, Pussan, Korea) product and the zirconia abutment was prepared via replication of a cemented abutment. The crowns were prepared via CAM/CAM with a thickness of 1.5 mm and were cemented to the abutments using RelyX(TM) UniCem cement. A universal testing machine was used to apply load at 30 degrees and measure fracture strength of the zirconia abutment. RESULTS: Fracture strength of the abutments for Group 1, Group 2, Group 3, and Group 4 were 236.00 +/- 67.55 N, 599.00 +/- 15.80 N, 588.20 +/- 33.18 N, and 97.83 +/- 98.13 N, respectively. Group 1 showed a significantly lower value, as compared to the other groups (independent Mann-Whitney U-test. P.05). CONCLUSION: Zirconia abutment requires optimal thickness for fracture resistance. Within the limitation of this study, > 0.8 mm thickness is recommended for zirconia abutment in anterior implants.