Mechanical properties of a novel conical connection

Background

Numerous studies have shown that internal conical connections (CC) provide greater stability, fatigue performance and sealing than other commercially available implant-abutment connections. To further improve the mechanical properties of implant-abutment connections, the newly developed N1 implant system from Nobel Biocare introduces a novel internal conical connection that ensures precise fit of the abutment and prevents rotation when secured.

Aim/Hypothesis

In this study, the fatigue strength and the sealing effectiveness of the new connection design (Ø4.0 mm) was compared with a commercially successful CC design (Ø4.3 mm).

Material and Methods

Fatigue strength was evaluated in two different scenarios simulating loading situations for single-unit crowns (n = 24) and wide-span bridges (n = 48). Fatigue limits (FL) and medium fatigue limits (MFL) were calculated for all test groups. The connection sealing effectiveness was evaluated using a negative pressure method (n = 16), in which a vacuum was applied to the implant-abutment connection and the pressure build-up was monitored under cyclic loading with increasing load levels (0–120 N, 10 N increments).

Results

Compared to CC, the FL of the novel connection was 13% higher for the single unit crown and 17–31% higher for the bridge scenario (depending on the abutment angulation). The MFL for the novel connection was significantly higher in both scenarios (t-test, 1-tail, P < 0.001). Both connections provided effective sealing+ however, there was no significant difference between the connections (Mann-Whitney-U, P > 0.05).

Conclusion and Clinical Implications

In comparison to a clinically successful CC, the newly developed conical connection demonstrates superior fatigue strength and inhibits rotation while retaining the excellent sealing properties, indicating a significant improvement in the design of implant-abutment connections.