Biological and mechanical characterization of commercial and experimental periodontal surgical dressings

Abstract The objective of this study was to evaluate the biocompatibility and mechanical properties of two commercially available and one experimental periodontal dressing materials. The cytotoxicity of Periobond ® , Barricaid ® and one experimental periodontal dressing based on Exothane ® 8 monomer was tested on 3T3/NIH mouse fibroblast. Genotoxicity was assessed by micronuclei formation, and cell alterations were analyzed using light microscopy. Both biological assays were performed using the eluate obtained from specimens after 24, 72, or 168 hours of incubation. Mechanical characterization was assessed through the ultimate tensile strength and the water sorption and solubility tests. The significance level of α = 0.05 was used for all statistical analyses. All the materials promoted a cell viability lower than 60% in all evaluated times. In general, the cell viability was significantly reduced after 72 and 168h of specimens' incubation. Considering the factor material, there were not statistical differences in the cell viability (p = 0.156). The genotoxicity was not statistically significant among the groups in the different periods of time (p > 0.05). Differences in the ultimate tensile strength values were not statistically significant different among the groups (p = 0.125). Periobond ® showed the higher water sorption values (p < 0.001). Regarding solubility, there were no statistical differences between the groups (p = 0.098). All the periodontal dressing materials evaluated in this study exerted a cytotoxic effect against mouse fibroblasts, and their toxicity became more evident over time. Among the materials evaluated, the experimental light-cure type has shown overall similar properties to the commercial references.

Exploratory and confirmatory factorial analysis of the OHIP-Edent instrument

Abstract Several instruments have been used to measure oral health-related quality of life (OHRQoL). The Oral Health Impact Profile (OHIP) questionnaire was based on the concept that sequential events related to oral diseases can cause discomfort, functional limitations and consequently, result in dysfunctions and even disabilities. There are few studies in the literature that structurally analyze the instruments to verify whether they measure the requirements to which they were designed to. The objective of the study was to evaluate the internal structure of the OHIP-Edent questionnaire. The OHIP-Edent was administered to 54 edentulous patients' wearers of conventional complete dentures. For structural analysis, an exploratory factorial analysis (EFA) was carried out. After determining the internal consistency of the model (Cronbach's alpha = 0.88), the fit was checked using the root mean square error approach (value 0.04), the comparative fit index (value 0.982) and the Tucker-Lewis index (value 0.976). After analysis of the 19 questions and the seven domains proposed in the OHIP-Edent questionnaire, the hypothetical factorial model showed three dimensions denominated "Physical Impact", "Psychological Impact" and "Social Impact". In this sample of conventional complete denture wearers, the OHIP-Edent seems adequate to measure the "Physical Impact", "Psychological Impact", and "Social Impact" of the OHRQoL. The confirmatory factorial analysis confirmed the model and, through adjustment indexes, it was verified that the three dimensions have convergence and consistence adequate in order to characterize the OHRQoL construct with validity.

O cálculo dental e a doença periodontal / Dental calculus and periodontal disease ­ a literature review

A doença periodontal (DP) é uma infecção crônica em resposta à presença de bactérias nos tecidos ao redor do dente, sendo definida como uma doença sujeito e sítio-específica, que evolui continuamente com períodos de exacerbação e de remissão. É uma patologia fortemente associada à presença de cálculo dentário em superfícies radiculares, porém, a superfície áspera do cálculo dental por si só não é suficiente para induzir à inflamação nos tecidos periodontais adjacentes. O cálculo dental atua como um substrato ideal para a colonização microbiana subgengival, e seu papel no desenvolvimento da doença periodontal tem sido investigado em vários estudos. Esta revisão buscou encontrar na literatura disponível estudos recentes sobre a relação existente entre o cálculo dental e a doença periodontal. Diante dos artigos encontrados, concluiu-se que a superfície porosa do cálculo dental abriga um biofilme viável, que propicia o crescimento e o desenvolvimento de periodontopatógenos. Ainda, pôde-se concluir que o papel do cálculo dental na etiologia da DP é secundário e que sua remoção da superfície dentária é essencial na fase inicial da terapia periodontal. Entretanto, nenhum método utilizado para o debridamento da superfície dental é eficaz na eliminação total do cálculo.

Periodontal disease (PD) is a site-specific, chronic infection in response to bacteria surrounding teeth, with periods of exacerbation and remission. It has been strongly associated to dental calculus (DC) at root surfaces; however, the rough nature of radicular tissues is not enough to trigger soft tissue adjacent infl ammation. The dental calculus act as an ideal substrate for subgingival colonization and its role on the development of periodontal disease has been investigated in several articles. The review aimed to identify recent studies on the relationship between PD and dental calculus. Based on the available data, it can be stated that the porous nature of dental calculus harbors an active biofi lm allowing for growth and development of periodontopathogenic microorganisms. Also, it can be said that DC has a secondary role on the PD etiology, and that its removal remains essential in the early phase of periodontal therapy. Nevertheless, no actual debridement method is effective for complete elimination of DC.

Avaliação de uma proposta educativa em saúde bucal aplicada ao ensino básico / Evaluation of an oral health educational purpose applied to primary education

OBJETIVO: Este estudo avaliou a assimilação e as práticas preventivas em saúde bucal adotadas por professores e alunos após um programa educativo em saúde bucal em uma escola pública de ensino fundamental. MATERIAIS E MÉTODOS: O programa foi desenvolvido por integrantes dos cursos de Odontologia e Pedagogia de uma instituição de ensino superior e visou discutir o papel da escola na educação em saúde. Atividades de formação continuada foram realizadas com professores e alunos da 3ª série (4º ano). Assuntos de saúde bucal foram discutidos com professores e alunos para determinar as suas ideias e conhecimentos sobre a saúde oral. Os efeitos das intervenções educativas foram coletadas e avaliadas. RESULTADOS: Com este programa educacional, foi possível verificar a importância dos professores como multiplicadores de saúde entre as crianças, mas a falta de treinamento foi observado. Ao longo e após a intervenção, houve mudança nos hábitos de higiene bucal dos alunos. CONCLUSÕES: Concluiu-se que a melhoria da saúde oral esteve associada com o programa educativo e preventivo. Entretanto o estudo apontou a necessidade de repensar as práticas educativas para a saúde bucal

AIM: This study evaluated the assimilation and preventive oral health practices of teachers and students after an oral health educational program in a public elementary school. MATERIAL AND METHODS: The program was developed by members of the Dentistry and Pedagogy courses from a higher education institution and aimed to discuss the school role in health education. Continuing education activities were performed with teachers and a group of students from the third grade (4th year). Oral health subjects were discussed with teachers and students to determine their ideas and knowledge on oral health. The effects of the educational interventions were recorded and evaluated. RESULTS: With this educational program it was possible to check the importance of teachers as health multipliers among children, but a lack of training was observed. Along and after the intervention, there was change in oral hygiene habits of students. CONCLUSION: It was concluded that the oral health improvement was associated with the educational and preventive program. However the study pointed out the need to rethink the educative actions

Use of Fusidic Acid for Desquamative Gingivitis Treatment: 1-Year Follow-Up

This study evaluated retrospectively the effect of fusidic acid on the management of desquamative gingivitis (DG). The study population consisted of 15 patients with DG. Patients were requested to make topical application of 2% fusidic acid ointment 4 times a day for 6 weeks. Clinical assessments were recorded at baseline, at 6 weeks and 12 months after beginning the therapy. Patients' examination involved lesion size area, pain score and impact on daily activities. All patients presented lesions in maxilla; in 9 patients (60.0%) lesions were predominately at the anterior region and 6 (40.0%) at the posterior region of maxilla. Treatment significantly (p<0.05) reduced the pain intensity (from 5.4±1.12 to 1.16±0.97) and its periodicity (from 53.33% with pain>3 x/week to 13.33%), and the lesion size in 72.47% (±4.12) immediately after 6 weeks of treatment. Improvements were sustained for 12 months compared to baseline (p<0.001). It also reduced the impact of disease in daily activities (eating and oral hygiene performance), and improved the emotional condition of patients, who reported better social relationships and habits. Topical application of fusidic acid may be a possible alternative local palliative therapy for desquamative gingivitis treatment.

Este estudo avaliou retrospectivamente o efeito do ácido fusídico sobre o manejo da gengivite descamativa (DG). A população do estudo consistiu de 15 pacientes com DG. Os pacientes foram solicitados a fazer aplicação tópica de pomada de ácido fusídico 2% 4 vezes ao dia, durante 6 semanas. As avaliações clínicas foram registradas no início do estudo, em 6 semanas e 12 meses após o início da terapia. O exame dos pacientes envolveu tamanho da área da lesão, intensidade da dor e impacto nas atividades diárias. Todos os pacientes apresentaram lesões na maxila; em 9 pacientes (60,0%) as lesões foram predominantemente na região anterior e em 6 (40,0%) na região posterior da maxila. O tratamento significantemente (p<0,05) reduziu a intensidade da dor (de 5,4±1,12 para 1,16±0,97) e a sua periodicidade (de 53,33% com dor>3x/semana para 13,33%), e o tamanho da lesão em 72,47% (±4,12) imediatamente após 6 semanas de tratamento. As melhorias foram sustentadas por 12 meses, quando comparado aos valores iniciais (p<0,001). Também reduziu o impacto da doença nas atividades diárias (alimentação e desempenho de higiene oral), e melhorou a condição emocional dos pacientes, que relataram melhores relações e hábitos sociais. A aplicação tópica de ácido fusídico pode ser uma alternativa para terapia local paliativa no tratamento de gengivite descamativa.

Genotoxic potential of 10% and 16% Carbamide Peroxide in dental bleaching

Dental bleaching has become one of the most frequently requested esthetic treatments in dental offices. Despite the high clinical success observed with this procedure, some adverse effects have been reported, including a potential for developing premalignant lesions, root resorption and tooth sensitivity, especially when misused. The aim of this study was to evaluate the genotoxic response using a micronucleus (MN) assay, after the application of two concentrations of carbamide peroxide. Thirty-seven patients were divided into two groups and randomly received either a 10% carbamide peroxide (CP) (19) or a 16% carbamide peroxide (18) concentration for 21 days in individual dental trays. Gingival margin cells were collected immediately before the first use (baseline), and then 15 and 45 days after baseline. The cells were placed on a histological slide, stained by the Feulgen technique, and evaluated by an experienced blinded examiner. One thousand cells per slide were counted, and the MN rate was determined. The two groups were analyzed by the Wilcoxon rank-sum test and the Kruskal-Wallis equality-of-populations rank test. A slight increase in MN was observed for both groups, in comparison with the baseline, at 15 days. However, no difference was observed between the two groups (10% and 16%), at either 15 or 45 days (p = 0.90). When bleaching is not prolonged or not performed very frequently, bleaching agents containing carbamide peroxide alone will not cause mutagenic stress on gingival epithelial cells.

Blood clot stabilization on root dentin conditioned by the combination of tetracycline and EDTA

AIM: To assess the combined use of tetracycline (TTC) and ethylenediaminetetraacetic acid (EDTA) on clot formation, considering that EDTA may neutralize TTC acidity. METHODS: Planed human tooth roots were treated with saline solution, EDTA, TTC and their combination (EDTA followed by TTC and TTC before EDTA). Fresh human blood was applied on the conditioned surfaces to check clot adhesion and stabilization. A previously calibrated (kappa = 0.93) and blinded examiner scored scanning electron micrographs of the samples. Statistical analyses were performed using one-way ANOVA and Tukey's test. RESULTS: Application of TTC before EDTA presented the best results with the highest number of cells adhered to the root surface (p=0.046). Use of EDTA alone and EDTA before TTC disturbed clot stabilization when compared to control group (p<0.01). CONCLUSIONS: The use of TTC before EDTA seems to be able to keep blood cells viable to establish an organized clot and could be used by clinicians together with the conventional mechanical root scaling and planing...

Non-white people have a greater risk for maxillofacial trauma: findings from a 24-month retrospective study in Brazil

AIM: To identify the predominant causes and types of maxillofacial trauma in Brazil. METHODS: Reports of corporal trauma (7,536) between 2009-2010 in the Brazilian Institute of Forensic Medicine were analyzed as to the presence of maxillofacial traumas. Victims' demographic and trauma characteristics were recorded. RESULTS: Data were submitted to chi-square test and to multivariate Poisson regression. 778 reports referred maxillofacial trauma. Most victims were men (50.8%) around 27.6 years. Main causes were physical aggression (88.1%) and traffic accidents (6.7%). The most affected extraoral area was the middle third (60.7%). Risk for trauma in the middle third was significantly higher among patients aged 61-75 (RR 1.32), and non-white patients (black-skinned RR 1.21; brown-skinned RR 1.18); while falls were associated with trauma in the lower third (RR1.79). CONCLUSIONS: Violence was the main cause of maxillofacial trauma. Prevention of interpersonal violence may be a key element to prevent maxillofacial trauma.

Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

OBJECTIVES: The aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning. MATERIAL AND METHODS: A total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group). After laboratorial processing, the samples were analyzed under scanning electron microscopy. A previously calibrated and blind examiner evaluated micrographs of the samples. Non-parametric statistical analysis was performed to analyze the data obtained. RESULTS: Brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. Sodium citrate exposed collagen fibers in a few number of samples. CONCLUSION: Despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. Sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning.

Principais índices clínico-visuais para classificação de lesões de cárie e doença periodontal / Main indices for clinical and visual classification of caries and periodontal disease

A organização do biofilme bacteriano e sua atividade metabólica sobre os tecidos bucais podem ter como consequência o aparecimento das doenças cárie e periodontal. Por isso, na prática clínica é importante que essas duas doenças sejam descritas, para que possam ser avaliadas, controladas, tratadas e monitoradas quanto à regressão, estabilização e reincidência. Para esse fim, alguns escores clínico-visuais são sugeridos na literatura e apresentados no presente artigo.

Frequency of class I anti-HLA alloantibodies in patients infected by HIV-1

The aim of this study was to evaluate the presence of class I anti-HLA alloantibodies in patients infected by HIV-1 and relate it with the different clinical courses of the disease. Blood samples were collected in EDTA tubes from 145 individuals. HIV-1 infection was confirmed by ELISA test. The presence of class I anti-HLA alloantibodies and HLA allele's were determined. Clinical evolution was set as fast (<1 year between diagnostic and death), moderate (1-3 years) or slow (>3 years). Class I anti-HLA alloantibodies presence was lower in healthy individuals than in those infected by HIV-1 (4.2 percent against 32.4 percent). However, an equal distribution of these alloantibodies was found among the individuals infected, independent on the clinical evolution. Thus, class I anti-HLA alloantibodies was not a determinant factor for patient worsening.

O objetivo deste estudo foi avaliar a presença de aloanticorpos anti-HLA classe I em pacientes infectados pelo HIV-1 e relacioná-la aos diferentes cursos clínicos da doença. Amostras de sangue de 145 indivíduos HIV positivo foram coletadas em tubos com EDTA. A infecção pelo HIV-1 foi confirmada por teste ELISA e a presença de aloanticorpos anti-HLA classe I determinada em seguida. A evolução clínica foi definida como rápida (<1 ano entre diagnóstico e morte), moderada (1-3 anos) ou lenta (>3 anos). A presença de aloanticorpos anti-HLA classe I foi menor em indivíduos saudáveis em relação aos infectados pelo HIV-1 (4,2 por cento contra 32,4 por cento). Porém, a distribuição destes aloanticorpos entre os indivíduos infectados foi igual, independente da evolução clínica. Deste modo, a presença de aloanticorpos anti-HLA classe I não é um fator determinante na piora clínica do paciente.

Papel das proteínas intracelulares nod e da proteína adaptadora myD88 na regulação de espressão de RANKL e modulação da resposta inflamatória induzidos por antígenos bacterianos in vitro: estudo em células relevantes de periodonto / Role of nod an myD88 proteins on the regulation of bacterial antigen-induced expression of RANKL and on the modulation of inflammation: a study on relevant cells of the periodontium

A reabsorcao do osso alveolar e uma das principais caracteristicas associadas a progressao da doenca periodontal. Apesar da enorme complexidade da microbiota envolvida, considera-se que bacterias Gram-negativas tenham um papel relevante em sua etiopatogenese. Um dos fatores de virulencia destes microrganismos e representado por um componente de sua parede externa denominado lipopolissacarideo (LPS). A presenca de LPS na proximidade dos tecidos periodontais e capaz de induzir a producao de diversos mediadores inflamatorios que levam a degradacao tanto do tecido conjuntivo quanto osseo. Atualmente acredita-se que a interacao do ligante do receptor-ativador do fator nuclear kappa-B (RANKL) com seu receptor (RANK) presente em precursores hematopoieticos e necessaria e suficiente para a inducao da diferenciacao de osteoclastos. Por outro lado, a ligacao de RANKL com seu falso-receptor, denominado osteoprotegerina (OPG), reduz sua biodisponibilidade e inibe, desta forma, a osteoclastogenese. Assim, a razao da expressao de RANKL e OPG e considerada como o principal determinante do “turnover” do tecido osseo. A producao de RANKL e OPG depende das vias de sinalizacao ativadas, as quais sao influenciadas pela natureza do estimulo extracelular. Atualmente, a familia de receptores NLRs (nod-like receptors) foi identificada como receptor intracelular para componentes bacterianos e agentes moduladores de diferentes vias de sinalizacao. Considerando a relevancia do LPS bacteriano na patogenese da doenca periodontal, o papel do RANKL no processo de reabsorcao ossea e a possivel implicacao das proteinas Nod na transducao de sinais regulando a expressao de RANKL, o objetivo geral deste projeto foi estudar os mecanismos de regulacao da expressao de RANKL induzido por LPS bacteriano em celulas relevantes do periodonto (macrofagos, osteoblastos e fibroblastos). Os objetivos especificos propostos...

Bone resorption is one of the major characteristics of destructive periodontal disease. Despite the great number of different bacterial species in the dental biofilm, Gramnegative microorganisms were demonstrated to have a very important role on periodontal disease pathogenesis. Lipopolysaccharide (LPS) is a bacterial cell wall component, which is acknowledged as one of the main virulence factors of these microorganisms. The mere presence of LPS in proximity with the periodontal tissues initiates the expression and production of inflammatory mediators and other cytokines which can culminate in degradation of both soft and hard tissues. It is currently accepted that the interaction between receptor-activator of nuclear factor kappa-B ligand (RANKL) and its receptor (RANK) is both necessary and sufficient to induce osteoclast differentiation and activation. However, RANKL can interact with its soluble decoy receptor osteoprotegerin (OPG) inhibiting osteoclastogenesis by decreasing the bioavailability of RANKL. Production of RANKL/OPG is the result of the signaling pathways activated by external stimuli. Recently, the NLR (nod-like receptors) family was identified as cytosolic receptors for bacterial components and also, as capable of modulating different signaling pathways. Considering the relevance of LPS and RANKL in bone resorption and the possible implication of Nod proteins in signal transduction regulating RANKL expression, the aim of this study was to evaluate the influence of different intracellular signaling pathways on the regulation of RANKL expression induced by LPS in relevant cells of the periodontium (macrophages, osteoblasts and fibroblasts). The specific objectives proposed were to determine after LPS and interleukin-1 beta stimulation the role of MyD88-dependent and independent signaling pathways, Nod1 and Nod2 on the expression of RANKL, OPG, IL-10 and IFN-beta...

Bone regeneration after demineralized bone matrix and castor oil (Ricinus communis) polyurethane implantation

Innocuous biocompatible materials have been searched to repair or reconstruct bone defects. Their goal is to restore the function of live or dead tissues. This study compared connective tissue and bone reaction when exposed to demineralized bovine bone matrix and a polyurethane resin derived from castor bean (Ricinus communis). Forty-five rats were assigned to 3 groups of 15 animals (control, bovine bone and polyurethane). A cylindrical defect was created on mandible base and filled with bovine bone matrix and the polyurethane. Control group received no treatment. Analyses were performed after 15, 45 and 60 days (5 animals each). Histological analysis revealed connective tissue tolerance to bovine bone with local inflammatory response similar to that of the control group. After 15 days, all groups demonstrated similar outcomes, with mild inflammatory reaction, probably due to the surgical procedure rather than to the material. In the polymer group, after 60 days, scarce multinucleated cells could still be observed. In general, all groups showed good stability and osteogenic connective tissue with blood vessels into the surgical area. The results suggest biocompatibility of both materials, seen by their integration into rat mandible. Moreover, the polyurethane seems to be an alternative in bone reconstruction and it is an inexhaustible source of biomaterial.

Efeito da adição de açúcar e da diluição do suco de laranja natural na exposição de túbulos dentinários / Effect of sugar addition and dilution of natural orange juice on dentinal tubules exposure

A dieta ácida tem sido associada ao aparecimento e persistência da hipersensibilidade dentinária cervical. Além do pH, fatores como tipo de ácido e sua concentração, tempo de exposição e presença de açúcar podem influenciar no seu potencial erosivo. Porém, poucas informações estão disponíveis sobre essas variáveis. O objetivo deste trabalho foi avaliar in vitro o efeito da adição de sacarose e da diluição do suco de laranja natural sobre o grau de remoção de smear layer e exposição dos túbulos dentinários. Dentes humanos extraídos foram utilizados para obtenção de 40 amostras que foram divididas aleatoriamente nos Grupos: 1- suco de laranja natural + açúcar; 2- suco de laranja diluído + açúcar; 3- suco de laranja natural e 4- controle (água destilada). Duas formas de aplicação foram utilizadas em cada grupo: tópica e fricção. As fotomicrografias obtidas em microscopia de varredura foram avaliadas de acordo com um índice de remoção de smear layer. O teste Kruskall-Wallis demonstrou que na aplicação tópica apenas o Grupo 1 foi estatisticamente diferente do controle, resultando em maior remoção de smear layer. Já na fricção, o Grupo 3 foi significativamente diferente do controle. A remoção de smear layer não variou para nenhuma das substâncias segundo o modo de aplicação (teste Mann-Whitney). Concluiu-se que o suco de laranja natural pode remover smear layer radicular, não sendo influenciado pela forma de aplicação. Além disso, a diluição do suco natural tende a diminuir este efeito, enquanto a adição de sacarose tende a aumentar.

Dietary acids have been associated with the occurance and persistence of cevical dentin hypersensitivity. Besides the pH value, the erosive effect can be influenced by factors such as type of acid and concentration, exposition time and presence of sugar. However, little information is currently available about these variables. The aim of this in vitro study was to evaluate the effect of sugar (sucrose) addition and dilution of natural orange juice on smear layer removal and dentinal tubules exposure. Extracted human teeth were used to obtain 40 specimens that were randomly distributed into Groups: 1- natural orange juice + sugar, 2- diluited orange juice + sugar, 3- natural orange juice, 4- control (distilled water). Each group included two methods of application: topical and friction. The photomicrographs obtained with scanning microscope were assessed using an index of smear layer removal. Kruskall-Wallis test demonstrated that in the topical application only Group 1 was statistically different from the control, resulting in greater removal of smear layer. On the other hand, in the friction, Group 3 was significantly different from the control. For each of the groups, the smear layer differ with the method of application (Mann-Whitney test). It was concluded that natural orange juice can remove smear layer from radicular surfaces, regardless the type of application. Besides this effect tends to decrease with the natural juice dilution whereas sucrose addition tends to increase.

A scanning electron microscopy study of root surface smear layer removal after topical application of EDTA plus a detergent

O objetivo do presente estudo foi comparar, através de microscopia eletrônica de varredura, a remocão de smear layer de superfícies radiculares após aplicacão tópica de gel de EDTA com gel de EDTA-T (Texapon). Foram utilizados dentes humanos que foram submetidos a remocão de cemento radicular e raspagem. As amostras dos dentes foram divididas em 3 grupos: Grupo I- (controle) (n=20); Grupo II- gel de EDTA (pH 7,0) nas concentracões de 5%,10%,15%,20% e 24% (n=100); Grupo II -gel de EDTA-T (pH 7,0) nas concentracões acima descritas (n=100). As fotomicrografias foram avaliadas através de um índice e os dados foram estatisticamente analisados. Ambos os tratamentos com EDTA foram efetivos na remocão de smear layer quando comparados ao grupo controle. O gel de EDTA a 5% demonstrou maior capacidade na remocão de smear layer quando comparado com as concentracões de 15%, 20% e 24% (p<0,05). Não houve diferenca entre as concentracões de géis de EDTA-T (p>0,05). Os géis de EDTA foram mais efetivos que o EDTA-T nas concentracões de 5 e 10%. Os resultados sugerem que a aplicacão tópica de EDTA ou EDTA-T é efetiva na remocão de smear layer, principamente em baixas concentracões e a adicão do Texapon não promove vantagens neste tratamento.

Application of the total etching technique or self-etching primers on primary teeth after air abrasion / Aplicação da técnica de condicionamento total ou de "primers" autocondicionantes em dentes decíduos após abrasão a ar

Como o uso da abrasão a ar tem aumentado em odontopediatria, o objetivo deste trabalho foi avaliar a resistência ao cisalhamento da resina composta Z100 sobre a superfície dentinária de dentes decíduos após abrasionamento a ar associado ou não a técnica de condicionamento total (ácido fosfórico + Scotchbond Multi Purpose) ou "primer" autocondicionante (Clearfil SE Bond). A superfície oclusal de 25 molares decíduos foi removida para exposição completa da superfície dentinária. Após polimento com lixas abrasivas, foram divididos em 5 grupos (5 espécimes em cada) tratados por abrasão + adesivo Scotchbond (G1); condicionamento ácido + adesivo Scotchbond (G2); adesivo Clearfil (G3); abrasão a ar + condicionamento ácido + adesivo Scotchbond (G4); abrasão a ar + adesivo Clearfil (G5). Uma matriz bipartida foi adaptada à superfície dentinária e preenchida com resina composta. Após polimerização, corpos-de-prova de 2 mm x 6 mm foram obtidos. O teste de Duncan mostrou a desigualdade (G1 = G4) < (G2 = G3 = G5). Desse modo, conclui-se que, após o abrasionamento dentinário, deve ser utilizado o sistema de "primer" autocondicionante a fim de se obter maior força de adesão.

Blood cell attachment to root surfaces treated with EDTA gel

A raspagem gera "smear layer", a qual contém microrganismos e toxinas que podem interferir no reparo periodontal. Por esse motivo, diferentes substâncias têm sido empregadas para remover esta camada e expor fibras colágenas da superfície dental. A adesão de elementos sangüíneos a superfícies radiculares desmineralizadas e a estabilizacão do colágeno pelas fibras colágenas são de extrema importância no sucesso da cirurgia periodontal. O objetivo deste estudo foi avaliar os diferentes padrões de adsorcão e adesão de elementos sangüíneos a superfícies radiculares apenas irrigadas com água destilada e após aplicacão de um gel de EDTA manipulado ou um industrializado. Trinta amostras foram raspadas, eqüitativamente divididas em 3 grupos e tratadas com água destilada (controle), um gel de EDTA manipulado ou um industrializado. Imediatamente foram expostas a sangue fresco e preparadas para microscopia eletrônica de varredura. As superfícies dentinárias apenas raspadas apresentaram os melhores resultados, com moderada quantidade de células sangüíneas entremeadas em uma fina rede de fibrina. No grupo de EDTA manipulado, a rede de fibrina foi pouco visível com escassas células. Os piores resultados foram observados com o EDTA industrializado, caracterizados pela ausência de elementos sangüíneos. Estatisticamente houve diferenca apenas entre os grupos controle e EDTA industrializado. As superfícies apenas irrigadas apresentaram rede de fibrina mais bem organizada com células entremeadas.