Biocompatibility and Corrosion Resistance of Embrasure Screws: An In Vitro Evaluation Using MTT Assay and Electrochemical Analysis

Abstract

Introduction: The success of intraoral devices depends on their biocompatibility and resistance to corrosion in the oral environment. Embrasure screws are increasingly used in dental applications; however, their biological safety and electrochemical stability require validation.

Objectives: To validate the biocompatibility and resistance to corrosion of Embrasure screws.

Methods: Biocompatibility was evaluated using the MTT cytotoxicity assay on Human Adult Dermal Fibroblast (HDFa) cells through direct and indirect exposure methods. Cellular morphology was assessed using phase-contrast microscopy. Corrosion resistance was analyzed using potentiodynamic polarization in artificial saliva with a three-electrode electrochemical setup. Both unused and clinically used embrasure screws (after ~21 days of intraoral exposure) were evaluated.

Results MTT assay results demonstrated high cell viability in embrasure screw-treated groups, comparable to       control cells, indicating absence of cytotoxicity. Morphological analysis confirmed preservation of normal fibroblast architecture with no signs of cellular damage. Corrosion studies revealed minimal variation between unused and used screws, with high polarization resistance (Rp) and low corrosion current density (icorr), indicating excellent corrosion resistance even after intraoral exposure.

Conclusions: Embrasure screws exhibit excellent cytocompatibility and corrosion resistance, making them safe for intraoral use. Their stability after 21 days of exposure suggests reliable clinical performance in the oral environment.