The influences of N-acetyl cysteine (NAC) on the cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA)-based dental resin

Yang Jiao; Sai Ma; Jing Li; Lequn Shan; Yanwei Yang; Meng Li; Jihua Chen

doi:10.7717/peerj.868

The influences of N-acetyl cysteine (NAC) on the cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA)-based dental resin

PeerJ. 2015 Apr 23:3:e868. doi: 10.7717/peerj.868. eCollection 2015.

Authors

Yang Jiao¹, Sai Ma¹, Jing Li², Lequn Shan³, Yanwei Yang¹, Meng Li¹, Jihua Chen¹

Affiliations

¹ State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, the Fourth Military Medical University , Xi'an , PR China.
² Department of Orthopaedic Oncology, Xijing Hospital Affiliated to the Fourth Military Medical University , Xi'an , PR China.
³ Department of Orthopaedic Surgery, Tangdu hospital, the Fourth Military Medical University , Xi'an , PR China.

Abstract

Objectives. This study aimed to investigate the influences of N-acetyl cysteine (NAC) on cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA) dental resins. Methods. Experimental PMMA resin was prepared by incorporating various concentrations of NAC (0, 0.15, 0.3, 0.6 and 0.9 wt.%). MTT assay was performed to investigate viability of human dental pulp cells after exposure to extract of PMMA resin with or without NAC. Cell adhesion on resin specimens was examined with scanning electron microscopy. Degree of conversion was studied with Fourier Transform Infrared Spectroscopy (FTIR). Flexural strength, microhardness and surface roughness was evaluated using a universal testing machine, microhardness tester and optical profilometer, respectively. Results. Incorporation of NAC into PMMA resin significantly reduced its cytotoxicity and enhanced cell adhesion on its surface. NAC induced negative influences on the mechanical and physical properties of PMMA resin in a dose-dependent manner. The degree of conversion for all experimental PMMA resins reached as high as 72% after 24 h of polymerization. All the tested properties were maintained when the concentration of incorporated NAC was 0.15 wt.%. Conclusion. The addition of 0.15 wt.% NAC remarkably improved biocompatibility of PMMA resin without exerting significant negative influence on its mechanical and physical properties.

Keywords: Cell viability; Detoxification; Mechanical properties; N-acetyl cysteine (NAC); Poly-methylmethacrylate (PMMA).

Grants and funding

This study was financially supported by grant 81130078 (principal investigator Jihua Chen) and grant 81300927 (principal investigator Sai Ma) from the National Nature Science Foundation of China, and Program No. IRT13051 from the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.