Biochemical Markers of Bone Metabolism to Assess Dental Implant Osseointegration

Biochemical markers of bone metabolism have been identified in peri-implant crevicular fluid (PICF) from stably integrated implants. These findings suggest that biomarkers may be useful in evaluating early bone healing events for dental implants. Objective: This study was designed to investigate the presence of biomarkers in PICF over the first few months following implant placement. Methods: PICF samples were collected from three patients at time points ranging from 1 to 6 weeks, and in one patient, up to 4 months following the placement of dental implants. PICF was collected by placing methylcellulose strips into the sulcus along the mesial and distal surfaces of each implant for 30 s. Strips were pooled per implant, and the amount of PICF quantified by weight. Samples were stored at –80 degrees celcius prior to analysis. For analysis, PICF samples were eluted from methylcellulose strips using PBS containing 0.1% BSA and centrifugation. Biomarkers, pyridinoline (PYD; resorptive) and osteocalcin (OC; formative), were quantified by competitive enzyme immunoassay. Results: Measurable PICF was collected from 11 of 16 samplings in 4 patients. OC was identified in all 11 PICF samples, with mean levels from 0.022 (+0.11) pg/mL after 1 week to 0.45 (+0.19) pg/mL after 12-16 weeks (p=0.11). PYD was identified in 8/11 PICF samples with levels ranging from 0.0013 pmol/mL to 0.344 pmol/mL. On a per patient basis, the highest PYD levels were identified between 2 and 6 weeks after implant placement. Conclusions: This study is the first report in humans of identifiable biomarkers for bone metabolism in the PICF of implants during the early healing period. These findings support a potential role for both OC and PYD as markers assessing bone turnover following implant placement. Study supported by the ITI Foundation (TWO).