Evaluation of bond strength of three different aesthetic abutment material with different angles to the crowns produced by CAD/CAM system

Aim: The aim of this thesis is to evaluate the bond strength of three aesthetic abutment materials at different angulations with ti-base and monolithic zirconia crowns. Materials and Method: PVDF abutments were obtained prefabrically, zirconia and PEEK copings were manufactured by CAD/CAM system (n=12). Bonding surfaces of the copings and ti-bases were sandblasted with alumina and then metal primer was applied. Self-cure cement was used for cementation of copings to the ti-base. Monolithic zirconia crowns were produced for each abutment (n=72). The bonding surface of the crowns was air-abraded and crowns were cemented with self-adhesive cement. Data were analyzed by Kruskal-Wallis and Mann-Whitney-U tests after tensile bond strength tests. Results: No significant difference was found between abutments at 0° angulation, in the bond strength of abutment-crown interface, in comparison between groups (p>0.05). Regarding 15° angulated abutments, the highest bond strength value was found in zirconia abutments (p>0.05). In the evaluation of bond strength of abutments to crowns, bond strength of 15° angulated abutments of zirconia group were higher than PEEK and PVDF abutments (p<0.05). In the evaluation of bond strength of abutments to ti-base, PVDF abutments was highest and the PEEK abutments were the lowest (p <0.05). Conclusion: Bond strength of monolithic zirconia crowns were lower than the restorations used in routine clinical practice. While bond strength of zirconia and PVDF abutments were acceptable, further studies are necessary to improve the bond strength of PEEK abutments. KeyWords: Abutment, bond strength, monolithic zirconium, PEEK, PVDF, zirconia.