Increased Systemic Malondialdehyde Levels and Decreased Mo/Co, Co/Fe²⁺ Ratios in Patients with Long-Term Dental Titanium Implants and Amalgams

Introduction: the biological safety of dental biomaterials has been questioned in human studies.

Material and methods: Several heavy metals/oligoelements were compared by Inductive Coupled Mass Spectrometry (ICP-MS) in hair samples from 130 patients (n = 54 patients with long-term titanium dental implants and amalgams (A + I group), 51 patients with long-term dental amalgam alone (A group), as well as controls (n = 25: without dental materials) of similar age. All patients (except controls) had had titanium dental implants and/or dental amalgams for at least 10 years (average: 17). We evaluated whether A + I patients could present higher systemic malondialdehyde levels (MDA) as compared to the A group.

Results: The A + I group have lower molybdenum levels (A + I) and reduced Mo/Co and Mo/Fe²⁺ ratios, which could predispose them to oxidative stress by raising MDA levels as compared to the A group alone; our findings suggest that higher Co levels could enhance oxidative stress in the A + I group. However, there were no differences on metals from titanium alloy (Ti-6Al), Cr from crowns or Hg²⁺, Sn, Zn²⁺, Cu²⁺ levels between the A + I and A groups.

Conclusion: patients with long-term dental titanium and amalgams have systemic oxidative stress due to rising MDA levels and lower Mo/Co and Mo/Fe²⁺ ratios than those with amalgams alone.