No Evidence of Genotoxic Damage in a Group of Patients with Titanium Dental Implants and Different Metal Restorations in the Oral Cavity

Abstract

Titanium is the most widely used metal in implant dentistry. In spite of its biocompatibility, when it is released into the oral environment, it can have local negative biological effects. The aims of this study were to detect the concentration of metal ions in patients with dental implants, to evaluate whether or not their release might be influenced by the presence of other metals, and to assay whether these ions might provoke genotoxic damage in oral mucosa cells. One hundred five patients with a total of 180 dental implants were included. The sample was divided into seven groups (n = 15 per group). Group 1 consisted of patients with metal-porcelain fixed crowns on dental implants; Group 2, patients with metal-porcelain fixed crowns on teeth; Group 3, patients with dental amalgams; Group 4, patients with metal-porcelain fixed crowns on dental implants and metal-porcelain fixed crowns on teeth; Group 5, patients with metal-porcelain fixed crowns on dental implants and dental amalgams; and Group 6, patients with metal-porcelain fixed crowns on dental implants, metal-porcelain fixed crowns on teeth, and dental amalgams. Group 7 was the control group, without any dental treatment. The concentration of metal ions was detected using inductively coupled plasma mass spectrometry; genotoxicity was measured using the buccal micronucleus cytome assay protocol. Group 5 displayed the highest concentration of metal ions in parts per billion (Ti, Co, Ni, Zn, Pd, Sn, and Pb). Group 6 was characterized by the highest presence of Hg. No signs of genotoxic damage were found in any of the study groups. Patients with titanium dental implants combined with other metal restorations presented higher concentrations of metal ions, but no genotoxic damage was observed in oral mucosal epithelial cells.