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Artigo IPEN-doc 25707 Antibacterial resin-based composite containing chlorhexidine for dental applications2019 - BOARO, LETICIA C.C.; CAMPOS, LUIZA M.; VARCA, GUSTAVO H.C.; SANTOS, TAMIRIS M.R. dos; MARQUES, PAMELA A.; SUGII, MARI M.; SALDANHA, NATHALIA R.; COGO-MULLER, KARINA; BRANDT, WILLIAM C.; BRAGA, ROBERTO R.; PARRA, DUCLERC F.Objeticve. The aim of this study was to develop a composite material with antibacterial activ-ity using MMT loaded with clorhexidine (CHX). For that it was used a BisGMA/TEGDMAmatrix and added low concentration of MMT/CHX. The aim was to evaluate the drug releasecapacity of MMT, and not to provide reinforcement.Methods. Six experimental composites were made with organic matrix of BisGMA/TEGDMAin equal proportions by weight. The composites received organophlizated montmorillonitewith or without CHX. The concentrations were 2,5; 5 or 10% by weight. Degree of conversion(DC) was evaluated using FTIR (peak 6165 cm-1; n = 5). Specimens for flexural properties(10×2×1 mm) were immediate tested (24h). Elastic modulus(E) and flexural strength (FS)was measured using the three point bending test (n = 10). Inibition halo was used to test theantibacterial activity against Staphylococcus aureus, Streptococcus mutans, and Porphyromonasgingivalis (n = 5 for each bacteria). The inhibition of biofilm formation (BF) was evaluated byinserting polymerized disc of composite in to a culture media colonized with Streptococcusmutans (n = 10). The release of CHX was measured using ultraviolet (255 nm) for 10 days(n = 5). The data of degree of conversion was analysed using Kruskal–Wallis/ Mann–Whitney,and the other variables using two-way ANOVA/Tukey, always considering a global level ofsignificance of 5%.Results. DC ranged from 71% to 74%. E ranged from 5.7 to 8.1 GPa. FS ranged from 61.4 to74.7 MPa. There were no statistical differences among the groups for all the variables. Forthe three bacteria tested the composites with CHX loaded presented inhibition of growthfor all concentration, except for 2,5% that did not inihibited the growth of P. gingivalis. BFwas lower for the groups with 10% MMT/CHX, all groups presented BF, even those withoutCHX loaded. All concentrations presented release off CHX during all the 28 days analyzed. Conclusions. Within the limitation of this study it can be concluded that: all concentrations tested presented release of CHX and reduced BF. All concentration presented antibacterial activity for the three bacteria tested, except for 2,5% that did not inhibit the growth of P. gingivalis. The presence of MMT with CHX loaded did not interfere in the properties evaluated.Resumo IPEN-doc 24966 Conversion of endodontic sealer modified with nanoparticles carrying antibacterial drugs2017 - SANCHES, L.K.F.; CAMPOS, L.M.P.; PARRA, D.F.; BRAGA, R.R.; SANTOS, M.; BOARO, L.C.C.Purpose/aim: The aim of this study was to evaluate the polymeric conversion of a commercial endodontic sealer modified with montmorillonite nanoparticles carrying to different antibacterial drugs: clorhexidine (CHX) and metronidazole (MET). Materials and methods: The sealer used was AH Plus sealer, and 5% in weight was added of the nanoparticles carrying one of the drugs CHX or MET. Cylindrical specimens were made with 5 mm diameter and 1 mm thick (n = 5). The degree of conversion (DC) was determined using near FTIR. DC was evaluated using the absorption peak at 4529 cm−1 that decrease during polymerization, and the absorption peak at 4623 cm−1 which is unaltered as normalization. The measurements were obtained for each sample immediately, 4 h and 24 h after mixing the two pastes of the sealer. A group with no modification by the nanoparticle was added as a control. The data was analyzed using one-way ANOVA/Tukey (α = 5%). Results: Results are presented in Table 1. Table 1. Means (SD) for degree of conversion (%) at 4 and 24 h. No statistical difference was presented among groups for neither periods of evaluation. Drug DC (%) 4 h 24 h Control 35 (11) A 68 (8) A CHX 31 (11) A 81 (11) A MET 38 (6) A 77 (14) A Conclusions: Within the limitations of this study it can be concluded that addition of the nanoparticle carrying both drug did not influence the polymerization of the sealer.Resumo IPEN-doc 24964 Antibacterial activity of endodontic sealer modified with nanoparticles2017 - SILVA, L.T.S.; COGO-MULLER, K.; BRANDT, W.C.; CAMPOS, L.M.P.; PARRA, D.F.; SANTOS, M.; BOARO, L.C.C.Purpose/aim: The aim of this study was to evaluate the antibacterial activity of a commercial endodontic sealer modified with montmorillonite nanoparticles carrying to different drugs: clorhexidine (CHX) and metronidazole (MET). Materials and methods: The sealer used was AH Plus sealer, and 5% in weight was added of the nanoparticles carrying one of the drugs CHX or MET. Cylindrical specimens were made with 5 mm diameter and 1 mm thick (n = 5). The antibacterial activity was evaluated by the inhibition halo test. This method was conducted according to Clinical Standard Laboratory Institute M2-A8 protocol, with some modifications (CLSI, 2003). The bacteria selected were the E. Fecallis which is the most frequently bacteria found in recidivate apical infection. Discs specimens were positioned over the agar and plates were incubated in the appropriate conditions for 48 h. After this period, inhibition zones were measured using a calliper rule. A group with no modification by the nanoparticle was added as a control. The data was analyzed using Mann–Whitney (alpha = 5%). Results: Results are presented in Table 1. For the control group no inhibition zone was formed, so the statistical analyze was performed only between the experimental groups. Table 1. Means (SD) for inhibition halo (mm). No statistical difference was presented between the drugs. Drug Inhibition halo (mm) Control 0 CHX 4.8 (1.4) A MET 4.0 (1.6) A Conclusions: Within the limitations of this study it can be concluded that the addition of the nanoparticle carrying both drugs added an antibacterial activity that was not found in the commercial sealer.Resumo IPEN-doc 23686 BisGMA/TEGDMA based material with antibacterial activity2016 - BOARO, L.; CAMPOS, L.M.; VARCA, G.H.C.; MARQUES, P.A.; PIMENTEL, A.C.; ROMAN-TORRES, C.V.; BRANDT, W.C.; COGO-MULLER, K.; BRAGA, R.R.; PARRA, D.F.