Impact of insertion torque and implant neck design on peri-implant bone level: a randomized split-mouth trial

Abstract

Purpose: The aim of this study is to assess the impact of insertion torque and implant neck design on peri-implant bone levels and gain insights into dynamic crestal tissue alterations by radiological, clinical, and biochemical examinations.

Material and methods: In this prospective trial, a total of 84 implants (four implants in each patient) in the interforaminal region of 21 edentulous mandibles were randomly alternated according to a split-mouth design. Implant placement was performed using different insertion torques (≤20 Ncm vs >50 Ncm). In each group, one machined and one anodized implant neck design (1.5 mm length) was used in the same jaw side. Evaluation of peri-implant tissues involved radiological, clinical examination and immunoassays for interleukin-1β.

Results: No significant influence of insertion torque or implant neck design on peri-implant bone level was found. Protein levels of interleukin-1β in the peri-implant crevicular fluid revealed no difference between both insertion torque groups and different neck designs.

Conclusion: Interactive effects of insertion torque and neck surface modification may exist; however, no clinically significant differences in marginal bone resorption after 1 year could be observed in the edentulous anterior mandible.

Keywords: bone-implant interface; crestal bone loss; crevicular fluid analysis; edentulous mandible; implant neck design; implant stability; insertion torque; osseointegration; tapered implants.