Implant Stability: A Prospective Clinical Study with a 2-year Follow-up

Abstract

Abstract Purpose: This prospective cohort study investigated the relationship between interproximal contact loss (ICL) and tactile sensitivity around implant-supported single-tooth restorations over an 18-month period. Materials and Methods: Twenty partially edentulous participants received posterior single-tooth implants restored with screw-retained monolithic zirconia crowns on custom titanium abutments. Interproximal contact tightness was quantitatively measured using a digital force gauge, and occlusal tactile sensitivity (osseoperception) was evaluated using progressively thicker occlusal foils. Contralateral natural teeth served as controls. Clinical assessments, including peri-implant plaque index, probing depths, and bleeding on probing, were performed at baseline and follow-up visits at 1, 3, 6, 12, and 18 months. Results: Only two of 20 implant sites (10%) developed open interproximal contacts, both within six months of crown delivery. Most contacts remained functionally closed, with only modest decreases in contact force over time. Tactile sensitivity thresholds were consistently higher for implant sites compared to control teeth, though differences were not statistically significant (p > 0.05). Peri-implant soft tissue health remained stable across all time points. Conclusions: The incidence of interproximal contact loss in this cohort was low, with no adverse effects on peri-implant health. Although implant restorations demonstrated higher tactile thresholds than natural teeth, perceptual function improved over time. These findings highlight the need for continued monitoring of contact stability, particularly in the mandible, and support the potential for limited osseoperception in implant-supported crowns.