Does the acidity of self-etching primers affect bond strength and surface morphology of enamel?

Purpose: This study examined the ultrastructure and microtensile bond strengths (TBS) of self-etching (with different acidity) and conventional adhesive systems bonded to unground enamel. Materials and Methods: Resin composite (Filtek Z250) buildups were bonded to unground enamel surfaces of third molars after adhesive application with the following materials: Clearfil SE Bond (CSE); Optibond Solo Plus Self-Etch (OP); Tyrian Self Priming Etching (TY), and the controls Scotchbond Multi-Purpose Plus (SBMP) and Single Bond (SB). Six teeth were assigned to each material. After storage in water for 24 h at 37 degrees C, the bonded specimens were sectioned into beams of approximately 0.8 mm(2) and subsequently subjected to mu TBS testing at a crosshead speed of 0.5 mm/min. The average values were subjected to one-way ANOVA (alpha = 0.05). The effect of surface conditioning of each material was observed under scanning electron microscopy (SEM). Results: The highest resin-enamel bond strength was observed for SBMP (22.7 +/- 5.2) and SB (26.7 +/- 5.2 MPa). The lowest mean bond strengths were 10.9 +/- 3.2 and 7.8 +/- 1.5 MPa for TY and OP, respectively. CSE showed an intermediate performance (18.7 +/- 4.6 MPa). An overall increase in porosity was evident along the entire enamel surface treated with the self-etching primers; however, no selective demineralization similar to that with 35% phosphoric acid was observed. Conclusion: The highest bond strength means and the more retentive etching pattern were observed for the two-step etch-and-rinse adhesives. Among the self-etching systems studied, Clearfil SE Bond should be preferred.82758

Additive Effect of rPb27 Immunization and Chemotherapy in Experimental Paracoccidioidomycosis

Paracoccidioidomycosis, PCM, the major systemic mycosis in Latin America, is caused by the termally dimorphic fungus Paracoccidioides brasiliensis and requires extended periods of chemotherapy with a significant frequency of relapsing disease. The search for new alternatives of treatment is necessary. rPb27 is an antigenic protein from P. brasiliensis that already showed a significant protective activity as a vaccine for PCM in experimental models. The cDNA of rPb27 was subcloned into a pET-DEST 42 plasmid, expressed in E. coli with a his-tag and purified by affinity chromatography. Immunization with this recombinant protein and chemotherapy were used together in an attempt to improve treatment of PCM. For this, BALB/c mice were challenged with pathogenic P. brasiliensis strain and after immunized with rPb27, in the presence of Corynebacterium parvum and Al(OH)3, some groups were also treated with fluconazole. After 40 days of treatment, the combined drug/rPb27 administration controlled PCM in the liver and spleen, with long lasting protection, and largely preserved tissues structures of these organs. Additionally, in the lungs after 40 days of treatment there was a significant reduction in the fungal load and size of lesions. At the same time, the levels of TNF-α were higher than infected-only mice. Moreover, significant levels of anti-rPb27 specific IgG1, IgG2a and IgG2b isotypes were detected in the sera of mice immunized with rPb27 fluconazole treated or not. These results showed an additive protective effect of rPb27 immunization and chemotherapy, suggesting that an rPb27-based vaccine can be used to enhance PCM antifungal treatment

Mucopolysaccharidosis I, II, and VI: Brief review and guidelines for treatment

Mucopolysaccharidoses (MPS) are rare genetic diseases caused by the deficiency of one of the lysosomal enzymes involved in the glycosaminoglycan (GAG) breakdown pathway. This metabolic block leads to the accumulation of GAG in various organs and tissues of the affected patients, resulting in a multisystemic clinical picture, sometimes including cognitive impairment. Until the beginning of the XXI century, treatment was mainly supportive. Bone marrow transplantation improved the natural course of the disease in some types of MPS, but the morbidity and mortality restricted its use to selected cases. The identification of the genes involved, the new molecular biology tools and the availability of animal models made it possible to develop specific enzyme replacement therapies (ERT) for these diseases. At present, a great number of Brazilian medical centers from all regions of the country have experience with ERT for MPS I, II, and VI, acquired not only through patient treatment but also in clinical trials. Taking the three types of MPS together, over 200 patients have been treated with ERT in our country. This document summarizes the experience of the professionals involved, along with the data available in the international literature, bringing together and harmonizing the information available on the management of these severe and progressive diseases, thus disclosing new prospects for Brazilian patients affected by these conditions

Desigualdades contextuais e individuais da prevalencia de dor dentaria em adultos e idosos no Brasil

Abstract published in English and Portuguese English title: Contextual and individual inequalities in dental pain prevalence among Brazilian adults and eldersThis study aimed to assess the prevalence of dental pain among adults and older people living in Brazil’s State capitals. Information was gathered from the Telephone Survey Surveillance System for Risk and Protective Factors for Chronic Diseases (VIGITEL) in 2009 (n = 54,367). Dental pain was the outcome. Geographic region, age, gender, race, schooling, private health coverage, smoking, and soft drink consumption were the explanatory variables. Multilevel Poisson regression models were performed. Prevalence of dental pain was 15.2%; Macapá and São Luís had prevalence rates greater than 20%; all capitals in the South and Southeast, plus Cuiabá, Campo Grande, Maceió, Recife, and Natal had prevalence rates less than 15%. Factors associated with increased prevalence of dental pain were the North and Northeast regions, female gender, black/brown skin color, lack of private health insurance, smoking, and soft drink consumption. Dental pain is a public health problem that should be monitored by health surveillance systems. = O objetivo deste estudo foi conhecer a prevalência de dor dentária e fatores associados em adultos e idosos residentes nas capitais brasileiras usando os dados do Sistema de Vigilância de Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico (VIGITEL), de 2009 (n = 54.367). Dor dentária foi a variável dependente. Macrorregião, idade, sexo, raça, escolaridade, posse de plano de saúde, tabagismo e consumo de refrigerantes foram as variáveis exploratórias. Foram realizadas regressões de Poisson multinível. A prevalência de dor dentária foi de 15,2%; Macapá e São Luís apresentaram prevalências maiores que 20% enquanto em todas as capitais do Sul e Sudeste, em Cuiabá, Campo Grande, Maceió, Recife e Natal foram encontradas prevalências menores que 15%. Residentes no Norte e Nordeste, mulheres, pretos e pardos, aqueles que não possuem plano de saúde, tabagistas e consumidores de refrigerantes apresentaram as maiores prevalências de dor dentária. A dor dentária é um problema de saúde pública que deve ser monitorado pelos sistemas de vigilância em saúde.Marco A. Peres, Betine Pinto Moehlecke Iser, Karen Glazer Peres, Deborah Carvalho Malta, José Leopoldo Ferreira Antune

Evaluation of silver methenamine method for nanoleakage

Objectives: The aim of this study was to evaluate nanoleakage patterns following silver methenamine staining of restorations bonded with a total-etch single bottle system, a self-etching primer system and a total-etch single bottle system after collagen depletion. Methods: The dentin bonding systems used in this study were Prime and bond 2.1 (PB) and Clearfil SE Bond (CSEB). Cavities were made in grounded labial surfaces of 15 extracted bovine lower incisors, randomly divided into 3 Groups. Group 1 (PB), Group 2 (CSEB) and Group 3 (PB/SH) PB after collagen depletion with sodium hypochlorite (SH). The specimens were restored, sectioned and submitted to silver methenamine staining, polished and observed with low-vacuum back-scattered SEM. One way ANOVA and multiple-comparison Tukey's test were used for statistical analysis of the leakage scores. Results: PB presented significantly greater silver deposition and a distinct pattern when compared to CSEB. No silver deposition was detected for PB after collagen depletion. Significance: The dentine bonding systems tested were unable to prevent nanoleakage when used according to the manufacturers' instructions; however, CSEB presented a tower level of silver deposition. Collagen depletion prior to PB application may prevent nanoleakage occurrence in dentine watts. Silver methenamine staining may be a useful method for detection of nanoleakage in dentine when the collagen fibrils remain exposed within the hybrid layers. (C) 2004 Elsevier Ltd. All rights reserved.32539139

Marginal adaptation and microtensile bond strength of composite indirect restorations bonded to dentin treated with adhesive and low-viscosity composite

Objectives. This study evaluated the marginal adaptation of composite indirect restorations bonded with dual curing resin cement after different strategies to seal dentin. Different bonding techniques associated or not with a low-viscosity composite resin (LVCR) were utilized. in addition, the bond strength between composite resin and pre-sealed dentin was evaluated in the buccal and pulpal walls of class I cavities, prepared for indirect restorations. Methods. Thirty-three freshly extracted human molars were used for this study, divided into three groups (n = 11) representing different techniques to seal dentin-(Group 1) Conventional technique: the adhesive system was applied and polymerized just before the cementation of the indirect restoration; (Group 2) Dual bonding technique: a first layer of the adhesive system was applied and polymerized just after preparation, and a second layer just before the final cementation; (Group 3) Resin coating technique: a LVCR was applied and polymerized after the first layer of the adhesive system, and before the impression. A further application of the adhesive system was performed before the placement of the restoration. The restorations were polished and a solution of acid red propylene-glycol was dropped on each specimen's occlusal surface for 10 s. The dye penetrations were captured under stereoscopic lens and the images were transferred to a computer with a measurement program, in order to determine the extension of the dye penetration. The microtensile bond strength test (mu TBS) was applied on pulpal (P) and buccal (B) walls of the restorations for Groups 1-3. The subgroups for mu TBS were: Group 1P (n = 13); Group 1B (n = 7); Group 2P (n = 6); Group 2B (n = 14); Group 3P (n = 14); Group 3B (n = 15). All specimens were sectioned to obtain an area of 0.8 mm(2). The specimens were mounted on a microtensile device and fractured using a universal testing machine at a cross-head speed of 1 mm/min. Failure modes were analyzed by SEM. One-way ANOVA and multiple-comparison Tukey's test were used for statistical analysis of the marginal adaptation scores and mu TBS test. Non-parametrical Kruskal-Wallis test was used for failure mode analysis. Results. Group 3 showed a significantly higher mean value of marginal dye penetration (45.59) when compared to Groups 1 (8.44) and 2 (18.92). For pulpal walls, Group 1P showed significantly higher mean mu TBS (25.93 +/- 2.27) when compared to Groups 2P (14.71 +/- 1.78) and 3P (16.07 +/- 2.81). There was no statistical difference between Groups 2P and 3P. For buccal walls, Group 2B presented significantly higher mean mu TBS (23.29 +/- 1.42), and Group 1B the lowest mean values (11.37 +/- 1.14). The failure mode analysis presented a considerable variation, according to the treatment and to the wall. The results of this study indicated that a previous sealing of dentin using the adhesive system, followed by a second application just before the cementation, is an effective alternative technique, since it maintains the marginal adaptation of indirect composite resin restorations, and improves the bond strength at the interface on buccal walls, which are the most critical regions for the long-term durability of these procedures. (c) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.23327928