5-year Results of Neoss Dental Implants Restored at Implant-Level. A Retrospective Follow-Up Study

One way of reducing the cost for screw-retained implant-supported dental prosthesis is to avoid the use of prosthetic abutments. However, concerns have been raised that this might lead to complications such as extensive marginal bone loss resorption and implant loss. The aim of the study was to retrospectively evaluate a cohort of consecutive patients treated with implant-level prosthetic constructions after 5 years in function. A total of 49 consecutive patients previously treated with 102 hydrophilic dental implants (Neoss Proactive, Neoss Ltd, Harrogate, UK) in two private dental clinics were included in the study. Fifty-four implants were installed in maxillae and 48 in mandibles to replace single teeth (n = 21), to support partial bridges (n = 26), total maxillary bridges (n = 2), or mandibular overdentures (n = 2). The majority of patients (n = 37) had implants placed in healed sites without any adjunctive procedures. In 12 patients, implants were immediately placed in extraction sockets or in conjunction with maxillary sinus floor augmentation. A submerged healing period of 3 to 4 months was used before healing abutments were connected to the implants. Impressions were taken after 7 to 10 days. Baseline (abutment connection surgery), 1and 5-year intraoral radiographs were used to measure marginal bone levels and calculate bone loss. Two mandibular implants were lost (2%) during the 5 years in function. The average marginal bone loss amounted to 0.7 ± 0.7 mm after 1 year and 0.9 ± 1.1 mm after 5 years. There was no correlation between insertion depth and bone loss. It is concluded that the use of screw-retained implantlevel prosthetic constructions resulted in high implant survival rate and minimal marginal bone loss after 5 years in function.