Abstract
Acrylic resins are widely used today both in pediatric dentistry and orthodontics for the manufacturing of space maintainers, interceptive devices or removable orthodontic appliances. All removable orthodontic appliances are composed of porous materials in which microorganisms (fungi, bacteria and viruses) infiltrate, attach and can form biofilms. For this study, two types of materials were chosen in order to test their influence on biofilm formation. For biofilm quantification a strain of Candida spp. was selected among 12 strains isolated from 23 pediatric patients, 7 to 12 years of age, wearing space maintainers or removable orthodontic appliances for at least 4 months at the time of harvest. The materials used in this experiment were the cold-cure acrylic Palapress®vario (Heraeus-Kulzer GmbH, Hanau, Germany) and the visible light acrylic polymerizable system Eclipse (Dentsply DeTrey, Konstanz, Germany). Images of the biofilm formed were obtained using a confocal laser scanning microscope. The images were analyzed using Comstat 2 software. The results showed that in both materials used, the average maximum thickness of the biofilm was above 10 µm. No significant differences were observed in biomass development of the biofilm between the two types of materials tested. Differences were observed in average thickness and maximum thickness of the biofilm. The thickest biofilm was formed on Palapress material. The biofilm formed on Eclipse material surfaces covers 66% of the total aria, while on Palapress material the biofilm covers only 40% of the total aria. These results explain why there are no differences in biomass between the biofilms formed on both materials despite the thickness and average colony size. Keywords: acrylic resins, biofilms, space maintainers, removable orthodontic appliances