Influence of the Prosthetic Interface and Manufactured Metal on the Mechanical Behavior of Two Extra-Narrow Implants.

PURPOSE: To evaluate the mechanical behavior of two types of dental implants (both 2.9 mm in diameter) using physical and virtual mechanical testing methodologies.

MATERIALS AND

METHODS

Two different extra-narrow Morse taper implant systems were evaluated: (1) Facility implants (2.9-mm diameter, 5-degree angulation of the internal conical portion) and (2) GM Narrow implants (2.9-mm diameter, 16-degree angulation of the internal conical portion). Both groups were evaluated on the results of the following methodologies: fractographic analyses and strength to failure, strain gauge, and thermomechanical cycling tests.

RESULTS

Statistical analysis revealed a significant distinction (P < .001) between groups: The mechanical fracture efficiency of the narrow group was 25% greater than the Facility group. The examination using a scanning electron microscope revealed that all implants experienced fractures, with a tendency for these fractures to occur in areas with a lack of continuity at the implant-abutment interface. There was no difference between groups considering the strain around the cervical region of all implants tested (P = .987). The survival rate of crowns and prosthetic connections was 100%. There was no crown loosening, prosthetic component detachment, or fracture.

CONCLUSIONS

The proposed modifications for the new implant and abutment system had a positive impact on the mechanical behavior of the implant, with a 25% increase in fracture resistance and better stress distribution. Clinically, the GM Narrow system has become more resistant, but both systems can securely be used in restricted areas with low masticatory effort, such as for lateral incisors and mandibular incisors.