Surface properties and color stability of an acrylic resin combined with an antimicrobial polymer

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Filling of simulated lateral canals with gutta-percha or thermoplastic polymer by warm vertical compaction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antimicrobial activity of a tissue conditioner combined with a biocide polymer

The characteristics of tissue conditioners support microorganism development that can threaten the health of the dentures user. The object of this study was to evaluate the effect on antimicrobial activity, roughness and wettability surface of a tissue conditioners material combined with the antimicrobial polymer poly (2-tert-butilaminoethyl) methacrylate (PTBAEMA). Specimens of tissue conditioner (Coe Soft(®)) were divided into three groups, according to the concentration of PTBAEMA incorporated (0, 10 and 25%). Antimicrobial activity was assessed by adherence assay of one of the microorganisms, Staphylococcus aureus, Streptococcus mutans and Candida albicans. Roughness measurements were made using a Mitutoyo SJ-400, and the mean arithmetic roughness values (Ra) obtained were used for the comparisons. The wettability properties were determined by contact angle measurements. The group containing 25% of PTBAEMA inhibited totally the S. aureus and S. mutans biofilm formation. A significant reduc tion in the S. aureus (Kruskal-Wallis, p = 0,001) and S. mutans (Kruscal-Wallis, p = 0,001) count for 10% PTBAEMA group compared with respective control group. No significant difference was found for C. albicans among PTBAEMA groups and control group (ANOVA, p > 0,05). Incorporating 10 and 25% PTBAEMA increased surface roughness and decreased contact angles (ANOVA and Tukey's post hoc tests, α = 5%). Incorporating 10% PTBAEMA into tissue conditioner increases wettability and roughness of tissue conditioner surface; and decreases the adhesion of S. mutans and S. aureus on material surface, but did not exhibit antimicrobial effect against C. albicans. The PTBAEMA incorporated into tissue conditioner could prevent biofilm formation on elderly patient.

Extraction of natural red colorants from the fermented broth of Penicillium purpurogenum using aqueous two-phase polymer systems

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Magnetically separable polymer (Mag-MIP) for selective analysis of biotin in food samples

This work presents an efficient method for the preparation of magnetic nanoparticles modified with molecularly imprinted polymers (Mag-MIP) through core-shell method for the determination of biotin in milk food samples. The functional monomer acrylic acid was selected from molecular modeling, EGDMA was used as cross-linking monomer and AIBN as radical initiator. The Mag-MIP and Mag-NIP were characterized by FTIR, magnetic hysteresis, XRD, SEM and N2-sorption measurements. The capacity of Mag-MIP for biotin adsorption, its kinetics and selectivity were studied in detail. The adsorption data was well described by Freundlich isotherm model with adsorption equilibrium constant (KF) of 1.46 mL g(-1). The selectivity experiments revealed that prepared Mag-MIP had higher selectivity toward biotin compared to other molecules with different chemical structure. The material was successfully applied for the determination of biotin in diverse milk samples using HPLC for quantification of the analyte, obtaining the mean value of 87.4% recovery.