Cytocompatibility and Microbiological Effects of Ti6Al4V Particles Generated During Implantoplasty on Human Fibroblasts, Osteoblasts, and Multispecies Oral Biofilm

Abstract

Objectives: This study aimed to evaluate the cytotoxic effects of Ti6Al4V particles and implantoplasty (IP)-treated surfaces on human fibroblasts and osteoblasts, and to investigate the influence of these particles on multispecies oral biofilm formation. Methods: Ti6Al4V particles generated during implantoplasty were collected. Human fibroblasts (HFF-1) and osteoblast-like cells (SaOs-2) were used to assess cytotoxicity through indirect lactate dehydrogenase (LDH) assays. Multispecies biofilms composed of Streptococcus oralis, Actinomyces viscosus, Veillonella parvula and Porphyromonas gingivalis were evaluated based on colony-forming units (CFUs) and metabolic activity. Fibroblasts and osteoblasts were co-cultured with biofilm-contaminated particles for 2, 4 and 6 h. Cell morphology and biofilm association were examined by phase-contrast microscopy, while metabolic activity was measured spectrophotometrically. Results: IP-treated surfaces showed no significant cytotoxicity (metabolic activity > 92%, LDH < 20%). Ti6Al4V particles selectively promoted A. viscosus and V. parvula growth (metabolic activity increases of ≈192% and ≈203%; CFU significantly higher versus controls, p < 0.05). Co-culture with biofilm-contaminated particles drastically reduced cell activity (fibroblasts < 25%, osteoblasts < 10%), whereas bacteria-free particles did not. Conclusions: Biofilm-contaminated particles released during implantoplasty markedly impair fibroblast and osteoblast cytocompatibility and selectively alter bacterial growth, whereas IP-treated surfaces per se are biocompatible. Minimizing particle dissemination and bacterial contamination during IP is therefore crucial.