Background: Further clarification of the early and late response of peri-implant tissues to surgical insertion and loading of dental implants and the potential associations among the various implant-related measures are likely to improve the evaluation/monitoring of implant sites. Thus, analyses were made of the volume and nitric oxide (NO) profile of peri-implant sulcus fluid (PISF), implant stability, and marginal bone level in relation to different prosthetic designs.

Methods: Seven totally edentulous subjects and 11 partially edentulous subjects were included. Resonance frequency analysis (RFA), marginal bone level measurements, PISF volume, and spectrophotometrically determined nitrite levels were analyzed comparatively at conventionally loaded (CL) implant sites and at implants with removable prostheses (RP; N = 14) and fixed prostheses (FP; N = 11) for a period of 12 months.

Results: At implant sites with RP, PISF volume decreased gradually and its lowest level occurred at the end of the experimental period. The PISF nitrite content increased until 6 months and was followed by a significant decrease at 12 months. Compared to baseline, RFA values exhibited a significant decrease at 1 and 3 months. Marginal bone level was significantly lower at all follow-up visits compared to baseline. More volumetric fluctuations of PISF was noted at implant sites with FP. The PISF nitrite content had decreased, compared to baseline, at 6, 9, and 12 months. A general stability was observed for RFA. The marginal bone loss observed at 6 months was followed by a gain at 12 months. An inverse relationship was noted between RFA values and marginal bone levels.

Conclusion: The prosthetic design particularly seems to affect the NO metabolism around CL implants, whereas it does not seem to have any impact on the stability of dental implants.