A new design of a multifunctional abutment to morse taper implant connection: experimental mechanical analysis

The objective of this study was to evaluate a new design of multifunctional abutment for Morse taper implant connections, relative to the retentive stability after the application of cyclic loads in cemented and screwed crowns. Multifunctional abutments with two different angulations in the seating portion of the crown were tested, forming 2 groups (n = 30 samples per group): Group Abut11, where Smart abutments with an angle of 11.42° were used; Group Abut5, where Ideale abutments with an angle of 5° were used. Fifteen samples from each group received cemented crowns (CC) and another fifteen screwed crowns (SC). All crown samples were subjected to the mechanical cycling test at 360,000 cycles at a frequency of 4 Hz and 150 N of the load. The samples with CC were subjected to the tensile test to remove the crowns, while in the samples with SC, the detorque value of the fastening crown screws was measured. The mean tensile strength value of CC in the Abut11 group was 131.9 ± 13.5 N and, in the Abut5 group was 230.9 ± 11.3 N; while the detorque mean value in samples with SC 5.8 ± 1.8 N for the Abut11 group and, 7.6 ± 1.1 N for Abut5 group. Significant statistical differences were found between the two groups in both situations tested (p < 0.05). The multifunctional abutments, presenting a lesser angulation of the crown-seating portion, showed higher values of retention of the CC and a lesser screw loosening of torque of the fixing screws in the SC after the application of cyclic loads when compared to the abutments with more angulation in the crown-seating portion.