A five-year retrospective follow-up study of tapered hydrophilic implants placed with or without GBR procedures

E62AF ePOSTER CLINICAL RESEARCH – SURGERY

Background: Preserving the peri-implant bone level is key for the longevity of an implant-supported prosthesis. Experimental studies have shown tapering to improve primary implant stability, especially in soft bone densities. In cases with NO-optimal bone conditions, guided bone regeneration (GBR) procedures may be applied which might challenge the long-term peri-implant bone preservation.

Aim/Hypothesis: The aim of the present study was to retrospectively evaluate the survival rate and factors affecting marginal bone levels around tapered implants with a hydrophilic surface after 5 years in function when placed with or without GBR procedures.

Materials and Methods: The study group consisted of 50 consecutive patients (18 male/ 33 female, mean age 56.2 years) previously treated with 101 dental implants (Neoss ProActive Tapered implants). Prosthetic solutions included single crowns, partial and full arch reconstructions, allowing both one- and two-stage surgical procedures with either delayed or immediate loading. Patients were scheduled for a six-month and then annually check-ups with clinical and radiographic examination during five years according to the clinic's regular treatment protocol. Subgroup analysis was performed for patients receiving implants with or without GBR procedures, 66 and 35 implants respectively. Marginal bone levels were measured from peri-apical radiographs taken at time of surgery and annual check-ups. Patient-, procedure-, and implant related factors was statistically analysed to evaluate their effect on marginal bone remodeling.

Results: No implant failure occurred during the five-year follow-up, resulting in an overall cumulative survival rate (CSR) of 100% following five years of function. The total marginal bone loss measured 0.5 ± 0.5 mm from insertion to 1-year and 0.7 ± 0.7 mm from insertion to 5 years. Between 1 year and 5 years, 0.1 ± 0.5 mm marginal bone loss was recorded. No implant showed more than 3.1 mm bone loss after 5 years. Implant diameter was found to affect bone remodelling, with wide implants losing less bone than narrow implants. No significant differences or correlations were seen for GBR, age, gender, smoking, jaw, implant position, biotype, bone quantity, bone quality, implant length, indication, and surgical/loading protocol.

Conclusions and Clinical Implications: The use of Neoss ProActive Tapered implants for prosthetic rehabilitation of consecutive patients resulted in predictable clinical and radiographic outcomes after five years of loading with no differences between augmented and NO-augmented sites.

Keywords: Tapered implants, Guided bone regeneration, Clinical study, Long-term follow-up, Bone remodeling