Physical training minimizes immunological dysfunction, oxidative stress and tissue destruction on experimental periodontitis in rats.

The objective of this study is to investigate the effects of a moderate intensity physical training protocol, on alveolar bone morphology of rats submitted to ligature-induced periodontitis. Twenty-eight male Wistar rats were divided into four groups, considering the presence/absence of periodontitis and presence/absence of training. The training protocol was performed on a treadmill, 30 min/day, 5 days a week, for 4 weeks. In the experimental periodontal breakdown, with/without training, ligatures were placed on the lower first molars on the 14th day of the experiment, and were followed until the end of the protocol. At the end of the experiment, animals were euthanized and samples of plasma and mandibles were collected for immunoenzymatic evaluation of interleukins (IL)-1ß, IL-6, TNF-α and IL-10, evaluation of serum concentrations of C-reactive protein, analysis of lipid peroxidation (LPO) and reduced glutathione, histological and microtomographic analyses were performed. Physical training resulted in a reduced levels of IL-1ß, IL-6, TNF-α C-reactive protein and LPO and an increase in the levels of IL-10 in rats with periodontitis (p<0.05); a reduction in the inflammatory infiltrate and decreased fiber degradation was identified in histological analysis. Additionally, it was shown a decrease in vertical bone loss and an increase in the bone volume/trabecular volume ratio was identified in periodontitis+physical training group (p<0.05). Based on the results, the practice of frequent physical exercise, at moderate intensity, can contribute to the reduction of damage related to the disproportionate inflammatory response in periodontitis.

Niobium silicate as a filler for an experimental photopolymerizable luting agent.

PURPOSE: To synthesize niobium silicate particles (SiNb) and incorporate into resin-based luting agents. METHODS: SiNb particles were synthesized and characterized by x-ray diffraction, FTIR spectroscopy, particle size, and specific surface area. Luting agents were formulated with 50 wt% BisGMA, 30 wt% TEGDMA and 20 wt% UDMA. BAPO was used as a photoinitiator in 1mol%. The SiNb particles were incorporated into the agents at concentrations of 50 wt% (SiNb50%) or 65% wt% (SiNb65%). Barium glass particles at the same concentrations were used as controls (SiBa50% and SiBa65%). Refractive index, degree of conversion (DC), polymerization kinetics, softening in solvent, radiopacity, film thickness, color stability, flexural strength (FS) and micro shear bond strength (µSBS) were evaluated. RESULTS: SiNb particles were successfully synthesized with an adequate structure to be applied as inorganic fillers. SiNb groups had higher DC, lower %ΔKHN, greater film thickness and greater radiopacity than the SiBa groups. Color stability was greater for SiNb50% and SiNb65% after six months of storage, as demonstrated by ΔE00. ΔWID values were lower for the SiBa groups. FS results decreased over time, and lower values were found for SiNb. In µSBS, the values of SiNb65% were higher at 24 h (45.22 MPa) and at six months (36.83 MPa), with statistically differences from values for the SiBa groups. CONCLUSIONS: SiNb particles were successfully synthesized using the sol-gel method, and their incorporation into luting agents at a concentration of up to 65% improved the physicomechanical characteristics and color stability of these agents.

Ionic liquid as antibacterial agent for an experimental orthodontic adhesive.

OBJECTIVE: The aim of this study was to formulate and evaluate experimental orthodontic adhesives with different concentrations of 1-n-butyl-3-methylimidazoilium bis(trifluoromethanesulfonyl)imide (BMIM.NTf2). METHODS: The experimental orthodontic adhesives were formulated with methacrylate monomers, photoinitiators and silica colloidal. The ionic liquid BMIM.NTf2 was synthesized and characterized. BMIM.NTf2 was added at 5 (G5%), 10 (G10%) and 15 (G15%) wt.%. One group contained no BMIM.NTf2 to function as control (GCtrl). The adhesives were evaluated for polymerization kinetics, degree of conversion (DC), Knoop hardness and softening in solvent, ultimate tensile strength (UTS), shear bond strength (SBS), thermogravimetric analysis (TGA), antibacterial activity and cytotoxicity. RESULTS: BMI.NTf2 showed the characteristic chemical peaks. The polymerization kinetics were different among the groups. G10% and G15% showed higher DC (p < 0.05). G5% and GCtrl had no differences for softening in solvent (p > 0.05). There were no differences for UTS (p > 0.05) and SBS (p > 0.05). TGA showed one different peak for G15%. All groups with BMIM.NTf2 showed antibacterial activity compared to GCtrl (p < 0.05) without cytotoxicity (p > 0.05). SIGNIFICANCE: To reduce biofilm formation around brackets and to prevent demineralization at susceptible sites, materials have been developed with antibacterial properties. In this study, a new experimental orthodontic adhesive was formulated with an imidazolium ionic liquid (BMIM.NTf2) as antibacterial agent. The incorporation of 5 wt.% of ionic liquid decreased biofilm formation without affecting the physico-chemical properties and cytotoxicity of an experimental orthodontic resin.

Antibacterial and Remineralizing Fillers in Experimental Orthodontic Adhesives.

Orthodontic adhesives with antimicrobial and remineralizing properties may be an alternative to control white spot lesions around brackets. The aim of this study is to develop an experimental orthodontic adhesive containing boron nitride nanotubes (BNNT) and alkyl trimethyl ammonium bromide (ATAB). Methacrylate (BisGMA and TEGDMA) monomers were used to formulate the adhesives. Four experimental groups were produced with the addition of 0.1 wt.% BNNT (GBNNT); 0.1 wt.% ATAB (GATAB); and 0.2 wt.% BNNT with ATAB (GBNNT/ATAB); in the control group, no fillers were added (GCtrl). The degree of conversion, cytotoxicity, softening in solvent, contact angle and free surface energy, antibacterial activity, shear bond strength, and mineral deposition were evaluated. Adhesives achieved degree of conversion higher than 50% and cell viability higher than 90%. GBNNT and GATAB adhesives exhibited reduced softening in solvent. Mean free surface energy was decreased in the GBNNT adhesive. Significant reduction in bacterial growth was observed in the GBNNT/ATAB. No statistical difference was found for shear bond strength. Mineral deposition was found in GBNNT, GATAB, and GBNNT/ATAB groups after 14 and 28 days. The addition of 0.2% BNNT/ATAB to an experimental orthodontic adhesive inhibited bacterial growth and induced mineral deposition without affecting the properties of the material.

Polímero de MMA para base de dentadura com a adição de subnitrato de bismuto / Addition of bismuth subnitrate in denture base MMA polymer

Objetivo: o presente estudo tem por objetivo avaliar a influência da adição de diferentes concentrações de subnitrato de bismuto (SN) nas propriedades de mate-riais para base protética. Materias e método: foi adicio-nada 0%, 1%, 2%, 5%, 10% e 20% de SN em peso em resina acrílica autopolimerizável da marca Clássico e submetidos aos ensaios de resistência à flexão, micro-dureza Knoop, radiopacidade, análise antimicrobiana, rugosidade e caracterização em micro-Raman. O teste estatístico escolhido foram o ANOVA de uma via e o teste de comparações múltiplas de Tukey. O nível de significância foi de 5% para todos os testes. Resultados: os resultados de resistência à flexão atingiram valores acima do recomendado pela ISO 1567. Quanto maior a concentração da carga de SN maior o valor de mi-crodureza Knoop, sendo estatisticamente significativo em 10% e 20% (p<0,001); os resultados da rugosidade mostraram valores abaixo do limiar, 0,2 µm. A adição de subnitrato de bismuto não obteve um potencial an-timicrobiano, mas apresentou uma maior radiopacida-de, (p<0,001). Conclusão: diante dos dados, conclui-se que a adição da carga de SN influencia nas proprie-dades mecânicas de resina acrílica significativamente, destacando-se que a radiopacidade desse material faci-lita a sua remoção quando ingerida ou aspirada.

Actividad antimicrobiana del cloruro de 2-metacriloil oxietil trimetilamonio contra Candida sp / Antimicrobial activity of [2-(methacryloyloxy)ethyl]trimethylammonium chloride against Candida spp

Antecedentes. La estomatitis protética es la forma más común de infección bucal producida por especies de Candida, siendo Candida albicans el agente etiológico más común. Diversos autores han intentado asociar agentes antifúngicos o antisépticos a los materiales de revestimiento blando o a las resinas acrílicas de las prótesis dentales, pero sin éxito. Por ello, se ha investigado un compuesto de amonio cuaternario (2-metacriloil oxietil trimetilamonio [MADQUAT]), que copolimeriza con los metacrilatos y que podría actuar como inhibidor de levaduras. Objetivos. El objetivo de este estudio fue evaluar la actividad in vitro del MADQUAT contra especies de Candida. Métodos. Se utilizaron 31 cepas de Candida para determinar la actividad antifúngica in vitro. Se determinó la concentración mínima inhibitoria (CMI) y la concentración mínima fungicida del MADQUAT, así como de la nistatina. Resultados. El MADQUAT presentó propiedades antifúngicas en las concentraciones entre 6,25 y > 100mg/ml y actividad fungicida entre 25 y > 100mg/ml. Los estudios cuantitativos de la actividad fungistática y fungicida del MADQUAT demostraron actividad fungistática contra todas las cepas de Candida albicans, Candida krusei y Candida parapsilosis, revelando actividad fungicida contra algunas cepas de otras especies. Conclusiones. El MADQUAT presenta actividad antifúngica contra Candida spp. Además, la sensibilidad a dicho compuesto es distinta entre las diferentes especies considerando los valores de la CMI y la actividad fungicida o fungistática(AU)

Background. Candida-associated denture stomatitis is the most common manifestation of oral candidal infection, caused mainly by Candida albicans. Several authors have attempted to add antifungal agents or antiseptics to denture temporary soft lining materials or to denture acrylic resins, without relevant results. Therefore, the investigation of a quaternary ammonium functionalized compound [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MADQUAT), which copolymerizes with methacrylates and which could act as a fungal inhibitor, is of paramount importance. Aims. To evaluate the in vitro activity of MADQUAT against Candida species. Methods. Thirty-one Candida strains were used to determine the in vitro antifungal activity of this compound. The minimum inhibitory concentrations and minimum fungicidal concentrations of MADQUAT and nystatin were determined. Results. MADQUAT showed antifungal properties at concentrations of 6.25 to > 100mg/ml, and fungicidal activity between 25 and > 100mg/ml. The quantitative determinations of the fungistatic and fungicidal activity of MADQUAT showed fungistatic activity against all Candida albicans, Candida krusei and Candida parapsilosis strains, revealing fungicidal activity against some strains of the other species. Conclusions. MADQUAT has antifungal activity against Candida spp. Moreover, the sensitivity to this substance varies across the different species in terms of MIC values and fungicidal or fungistatic activity(AU)