Investigation of Surface Morphology and Roughness of Dental Implant Platform and Abutment

Purpose: This study investigated the surface morphology and roughness of the dental implant platform and abutment at their junction interface, comparing parameters before and after mechanical assembly (screwing). Methods: The experimental specimens comprised 40 implants from the TBR, Bone Level M System (TBR, France) with a diameter of 4.7 mm and a length of 10 mm, and 40 matching abutments from the same system (Titanium Standard Abutment, TBR, France) with a diameter of 4 mm and a gingival height of 3 mm. All components were fabricated from Grade 4 titanium. The implants and abutments were divided into two equal groups. In the first group (control), 20 implants and 20 abutments remained unassembled. In the second group, 20 implants were coupled with 20 abutments and tightened to the manufacturer-recommended torque. To achieve this, the implants were stabilized with pliers to prevent rotation, and the abutments were screwed using a screwdriver and a torque wrench at 30 N.cm. Subsequently, the abutments were unscrewed counterclockwise. Surface evaluations were conducted using scanning electron microscopy (SEM) and 3D surface modeling. Results: The obtained results demonstrate a statistically significant reduction in the parameters reflecting the roughness of the implant platform. Based on the analysis, a pronounced decrease in the average roughness (Ra, Rq) of the abutment was observed (p < 0.001). Furthermore, it was established that the implant platform exhibits nearly twice the surface roughness of the abutment even in its baseline state. Conclusions: Within the limitations of this in vitro study, a single tightening and removal procedure was associated with measurable changes in the roughness parameters and surface morphology of the implant platform and abutment. These findings indicate microtopographic adaptation at the conical interface under the tested conditions; however, biomechanical reliability and resistance to bacterial micro-leakage were not evaluated.