Peri-implant Clinical Parameters During Osseointegration Phase: Site-specific Differences

Objectives: One-stage implant placement allows evaluation of early healing.  This preliminary study aimed to determine site-specific characteristics of peri-implant wounds.

Methods: Non smoker patients in need of single tooth replacement at two posterior sextants were included.  Bone level implants were simultaneously placed.  Resonance Frequency Analysis (RFA) was performed at placement, 1 and 4 weeks post-operatively. Bone plate and flap thicknesses were measured with a caliper. Plaque and gingival indices (PI and GI) and peri-implant sulcus depth (PSD) were determined at baseline and during healing. Crevicular fluid (CF) was collected by using sterile strips and volume was determined with Periotron^®.  Gingival tissue biopsies were obtained.  These samples were stored at -80°C for future protein/gene array experiments.

Results: Nine patients (5 female; 51±4.7yrs) were included.  Initial bone and flap thicknesses were similar at both sites (P>0.05).  Newly forming PSD ranged between 2 to 4 mm. RFA revealed an initial 68±2.4 ISQ unit for site I compared to 72±2.2 ISQ for site II.  These values changed to 75±1.6 (P=0.03) and 69±2 ISQ (P>0.05) at 4 weeks, respectively. PI stayed stable while GI decreased significantly (P=0.04), at both sites. Initial CF volume increase at week 1 diminished to baseline levels by week 4 (P=0.04 for site I; P>0.05 for site II). Local molecular wound marker expression is currently under investigation.   

Conclusions: Based on these preliminary findings, site-specific characteristics of peri-implant wound healing can be detected at two separate sites within the oral cavity.