Cytotoxicity of Two Autopolymerized Acrylic Resins Used in Orthodontics

Abstract

Objective: To test in vitro the null hypothesis that the toxic effect of different acrylic resins used in orthodontics cannot be reduced when a prior elution is performed. Materials and Methods: Three established cell lines were used (HeLa, NIH3T3, and Hep2) and cultured under standard conditions. Resin segments were immersed in a culture medium and left to elute for 24 and 48 hours. Cells were exposed to medium containing eluates for 24 or 48 hours. The 3-(4,5 dimethyl-2-thiazolyl)-2.5-diphenyl-2H-tetrazolium bromide (MTT) assay was used as the cytotoxicity test. Control cells contained standard medium with no eluate. Analysis of variance and Tukey test were used for statistical analysis. Results: Fibroblastic viability was not affected when the elution time was 24 hours, but treatments showed higher cell viability than controls when the elution time was 48 hours. When left to elute for 24 hours, both resins had a cytotoxic effect on epithelial cells, but this effect was not observed when the elution time was 48 hours. Conclusions: The hypothesis was rejected as both tested materials showed lower cytotoxic effect when treated with 48-hour elutes compared with 24-hour elutes, which indicates that a longer elution time reduces resin toxicity.

Evaluation of Nickel Ion Release from Orthodontic Wires in Different Types of Artificial Saliva

“…Most of these objectives require replacement or alteration of the existing dental structures, as well as changes in the tooth positioning, developing and selecting biocompatible materials have been one of the major challenges in dentistry.P (1) P Metals, ceramics, polymers and composites are the four groups of materials that are currently employed.P (2) Little scientific information on these materials was available until the middle of the last century. Toxic, inflammatory, allergic or mutagenic reactions are the possible biological response to these materials.P (3)(4)(5)(6) P Toxicity is one of the main parameters of evaluating the biological response and the potential damage to cells and tissues related to the use of such materials.P (7)(8)(9)…”

Advancements in Soft-Tissue Prosthetics Part B: The Chemistry of Imitating Life

“…For intra-oral applications, polishing is required to reduce gingival (gum) inflammation. Acrylic resin can be exposed to heat treatments or water immersion for at least 24 h to reduce the quantity of residues (Siqueira Gonçalves et al, 2008;Ata and Yavuzyılmaz, 2009;Bural et al, 2011;Saravi et al, 2012;Goiato et al, 2014). Additionally, the replacement of 10wt% of MMA monomer with dimethyl itaconate (DMI) and di-nbutyl itaconate (DBI) can reduce water sorption and residual monomer content (Spasojevic et al, 2015).…”

Effects of Baseplates of Orthodontic Appliances with in situ generated Silver Nanoparticles on Cariogenic Bacteria: A Randomized, Doubleblind Cross-over Clinical Trial

“…1 In addition, PMMAs are used for individual impression trays and early orthodontic appliances for patients with cleft lip and palate and as splints for orthognathic surgery. Currently, PMMA resins are commonly used in routine ORIGINAL RESEARCH…”