Micromovement Evaluation of Original and Compatible Abutments at the Implant-abutment Interface.

INTRODUCTION: Use of compatible abutments may increase micromovements between the abutments, and the inner part of the implant may increase the stress on marginal bone level. Also micromovement will change the volume of the inner space of the implant-abutment complex. The resulting pumping effect can transport even initially immobile microorganisms from the exterior to the interior and vice versa.

OBJECTIVES: The purpose of the study was to evaluate the mechanical comportment of OsseoSpeed™ Tx implants connected with original and compatible abutments in vitro under simulated clinical loading conditions.

MATERIALS AND METHODS: A total of 15 OsseoSpeed™ TX implants (4 × 11 mm) were used and divided into three groups (n = 5). Three types of abutments were used in the study; group I: Five original Ti Design™ abutments, group II: Five Natea™ abutments, and group III: Implanet™ abutments. Abutments used in groups II and III were all compatible with Astra Tech Implant System™. Implants were embedded into resin. Simulating the human masticatory cycle, the axial force vector was increased up to a defined maximum (25, 50, 75, 100, 125, 150, 175, and 200 N) and inclined 30° to the implant axis. A radiograph amplifier was used to convert the X-ray projection into a picture. The visual evaluation of the frames and the provided X-ray videos were evaluated for an existing microgap in width and length between the implant and the abutment.

RESULTS: An initial width gap was observed in groups II and III in four of the five samples with an average of 6.5 and 5 μm respectively. When the axial forces reach 75 N, only groups II and III demonstrated a gap width of 5.2 ± 3.63 and 4.8 ± 3.03 μm, and a gap length of 5.2 ± 3.63 and 94 ± 125.3 μm respectively. At 200 N, group I showed a gap width of 8.4 ± 1.67 μm and a gap length of 187.6 ± 43.6 μm, while groups II and III showed a gap width of 12.4 ± 3.29 and 22.8 ± 5.76 μm, and a gap length of 387.2 ± 84.36 and 641.2 ± 122.6 μm respectively.

CONCLUSION: Within the limitations of this study and under the parameters used and from the resulting data collected, we can presume that the use of compatible components leads to significant micromovement when compared with the use of original ones.

CLINICAL SIGNIFICANCE: The use of compatible prosthetic components with original implants showed significant micromovements when compared with the use of abutment and implant from the same manufacturer. Clinically, the micromovements when associated with leakage leads to bone loss around the neck of the implant and later to peri-implantitis.