Clinical follow-up was conducted on 127 cylindrical implants placed in 21 patients after 5 years of function: 75 implants were coated with titanium plasma spray (TPS) and 52 implants were coated with hydroxyapatite (HA). The aim of the study was to assess possible differences in clinical function and success rates for each implant type. Clinical and radiographic evaluations were conducted, and the periodontal indices of gingival bleeding, plaque, and calculus were measured. Cumulative data were analyzed for differences by implant type and jaw location. No significant differences were found between the 2 implant systems according to the periodontal parameters studied; however, 5-year success rates were 86.7% for TPS-coated implants and 94.3% for HA-coated implants. The periodontal probe index presented abnormal values in the patients with systemic disease and those who were provisionally restored with single-tooth restorations, complete screw-retained dentures, and fixed partial dentures. There were no differences regarding implant placement when mandibles and maxillae were compared. Long-term success rates were outstanding for HA-coated implants and acceptable for TPS-coated implants after 5 years of function. No significant differences were found between the 2 surfaces.

Implant stability is one of the main indicators of successful osseointegration. Although it has been measured in numerous studies, there has been little research on implant stability in regenerated bone. The study compares primary and secondary stability between implants placed in regenerated versus native bone and evaluates the influence of bone quality on the results. Sixty implants were placed in 31 patients: 30 implants inserted in native bone (non-regenerated) after a healing period of at least 6 months post-exodontia and 30 inserted in regenerated bone at 6 months after grafting with xenograft. Resonance frequency analysis (RFA) was used to obtain implant stability quotient (ISQ) values at baseline (implant placement), 8 weeks, and 12 weeks. Statistically significant differences were found between implants placed in regenerated bone and those placed in native bone at all measurement time points (p < 0.05). ISQ values were significantly influenced by bone quality at baseline (p < 0.05) but not at 8 or 12 weeks. Greater stability was obtained in implants placed in native bone; however, those placed in regenerated bone showed adequate primary and secondary stability for prosthetic loading. Bone quality influences the primary but not secondary stability of the implants in both native and regenerated bone.