Salivary pH Effect on Orthodontic Appliances: In Vitro Study of the SS/DLC System

Stainless steels (SS) are the most-used alloys for manufacturing fixed orthodontic appliances due to their attractive set of mechanical properties, biocompatibility, and high corrosion resistance. Nevertheless, during regular treatments–taking at least around 2 years–the intraoral environment inevitably degrades these bioalloys, releasing metallic ions into oral cavity. In first part this in vitro study, resistance commercial SS (brackets, tubes, bands) was evaluated Fusayama-Meyer artificial saliva pH values 2.3 6.8 over course 30 days. As expected, results corroborated that salivary highly influences behaviour. Released Ni, Cr, Fe were within dietary intake values. second part, a novel approach prevention based on chemical inertness DLC materials is presented. surfaces functionalized with biocompatible a-C:H-sputtered coatings submitted same experimental conditions. The anticorrosion ability system demonstrated, preventing pitting occurred substrates. Despite galvanic coupling effect presence Cr-based interlayer, study enhanced potential use reactive sputter-deposited a-C:H orthodontics.