An In Vitro Comparison of Cytotoxic Effects of Injection Molding, Computer-Aided Design and Computer-Aided Manufacturing Milling, and Rapid Prototyping Denture Base Resins

Address for correspondence :
Dr. Gajapathi Balaraman
gajapathiresearch@gmail.com

Abstract

Background: Residual monomer, resulting from incomplete conversion of monomers into polymer, has the potential to cause irritation,

inflammation, and an allergic response of the oral mucosa. Different processing techniques have an influence on the biocompatibility of denture

base acrylic resins. This study aims to compare the in vitro cytotoxicity of polymethyl methacrylate denture base acrylic resins processed by

injection molding technique, computer-aided design and computer-aided manufacturing (CAD/CAM)-milled and rapid prototyped technique

using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay. Materials and Methods: A total of 45 acrylic specimens

of 10 × 1 mm discs were fabricated. Study was conducted between four groups: Group I - Control, Group II - Injection molded samples

(SR Ivocap High Impact, Ivoclar Vivadent) (n = 15), Group III - CAD/CAM-milled specimens (Ruthinium, India), Group IV - CAD/CAM-Rapid

prototyped samples (NextDent system). MTT assay was performed for all samples at 24 and 48 h. Wilcoxon signed rank test was used

to compare means between paired data. For multiple group comparison, Kruskal–Wallis analysis of variance was used, followed by the

Mann–Whitney U test for individual pairwise comparisons. Results: Cytotoxicity of CAD-CAM-rapid prototyped samples was found to be

statistically the highest, followed by injection samples, and the least was observed in CAD/CAM-milled samples at 24 and 48 h, respectively.

Conclusion: CAD-CAM-rapid prototyped samples exhibit the least biocompatibility followed by injection molded and CAD/CAM-milled

samples.