Nanoporous TiO2 Thin Film on Titanium Oral Implants for Enhanced Human Soft Tissue Adhesion: A Light and Electron Microscopy Study

ABSTRACT Background: Previous experimental studies have demonstrated direct soft tissue attachment for nanoporous titanium dioxide (TiO2) thin film on implants, while implants without TiO2 thin film have not shown this capability. Purpose: The aims were to evaluate and compare TiO2 surface‐modified experimental microimplants with unmodified microimplants with respect to tissue interaction of the human oral mucosa evaluated by light microscopy on ground sections and semithin sections and transmission electron microscopy on ultrathin sections, and to characterize the inflammatory response and the level of the marginal bone resorption. Materials and Methods: The study was a single‐center, randomized, comparative, clinical investigation with intrasubject comparison of implants with and without TiO2 thin film in 15 patients. Results: Two comparator microimplants showed mild erythema and expulsion of fluids. The surrounding tissues around all test implants were clinically healthy. The oral mucosa in contact with the abutment part of the microimplant was 72% for the test implants and 48% for the comparator implants, a statistically significant difference (p = .0268). No statistically significant difference was found in other histological variables. The marginal bone loss in 14 weeks was 0.5 mm for the stable test (n = 11) and 1.7 mm for the stable comparator implants (n = 9; p = .0248). Conclusions: The nanoporous TiO2 surface modification has potential clinical benefits because of increased adherence of soft tissue and possible reduced bone resorption.