Study of the root dentin permeability of primary teeth. Cleansers and irrigation method evaluation

Orientador: Regina Maria Puppin-RontaniDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: Um dos principais objetivos do tratamento endodôntico é o debridamento do sistema de canais radiculares através da remoção dos restos pulpares, da smear layer e smear plugs, para eliminar a contaminação bacteriana e subprodutos da mesma, os quais podem se tornar reservatórios de irritantes no canal tratado. Além disso, as substâncias irrigadoras e os métodos de irrigação utilizados durante o preparo químico-mecânico, podem também contribuir para a remoção da smear layer e consequentemente alterar a permeabilidade dentinária. Dessa forma, os objetivos desta Dissertação foram: (1) discutir através da revisão da literatura, a eficácia de substâncias irrigadoras, bem como a influência de dois métodos de irrigação (irrigação manual ou ativação ultrasônica) utilizados durante o preparo químico-mecânico de dentes decíduos e permanentes, considerando a permeabilidade da dentina radicular; (2) correlacionar o índice de permeabilidade da dentina radicular de dentes decíduos sob a influência de substâncias irrigadoras associadas ou não a auxiliares de instrumentação (líquido de Dakin, líquido de Dakin associado ao peróxido de hidrogênio, solução salina associada à clorexidina gel e solução salina) e diferentes métodos de irrigação (irrigação manual ou ativação ultrasônica) aos seus aspectos morfológicos (presença ou ausência de smear layer). Baseando-se na revisão de literatura pôde-se concluir que as substâncias irrigadoras e associações utilizadas durante o tratamento endodôntico promoveram aumento da permeabilidade dentinária radicular de dentes permanentes e que não houve diferenças quanto à permeabilidade dentinária, quando comparada a irrigação realizada manualmente ou através de vibração ultrasônica. Não há estudos relacionados à permeabilidade radicular de dentes decíduos, quando estes são submetidos a substâncias irrigadoras e diferentes métodos de irrigação. A técnica de irrigação manual foi considerada mais efetiva do que a técnica de irrigação através de sistema de vibração ultrasônica, quanto à permeabilidade dentinária radicular de dentes decíduos. A presença da smear layer nas paredes radiculares foi um fator limitante à penetração do corante (índice de permeabilidade) para o terço médio quando dentes decíduos foram irrigados manualmente. O líquido de Dakin apresentou os maiores valores de índice de permeabilidade, nos três terços radiculares, sugerindo que essa solução irrigadora seja indicada para o tratamento endodôntico de dentes decíduos.Abstract: One of the main goals of root canal treatment is the cleaning of the entire root canal system, through removal of pulpal debris, smear layer and smear plugs in order to avoid harbor bacteria or bacterial by-products, providing a reservoir of potential irritants in treated root canal. In addition, the cleansers and irrigation methods used in the endodontic treatment, can also contribute with the smear layer removal and with permeability alterations. Thus, the aims of this Thesis was: (1) to discuss the efficacy of some cleansers, as well as the influence of two irrigation systems used during endodontic preparation of primary and permanent teeth (manual or ultrasonic vibration) with regard to root dentin permeability, based on a literature reviewing; (2) to correlate the dye permeability to morphological aspect (presence or absence of smear layer) of the primary root dentin wall, using scanning electron microscopy (SEM), regarding the endodontic preparation and irrigation methods. Based on literature review (1) it can be concluded that among the solutions used for permanent teeth, all solutions and associations studied increased the dentin permeability. There was no difference in the dentin permeability when comparing manual and ultrasonic irrigation. There are not enough papers focusing primary teeth on this subject to definitely establish the patterns of increased dentin permeability in tooth root canal treatment regarding the irrigating solutions and irrigation systems. The results of the second study showed that manual irrigation technique was better than ultrasonic one and that Dakin's liquid, Dakin's liquid associated with hydrogen peroxide, and saline solution showed the highest permeability index averages values. Regarding the correlation study, it could be concluded that the smear layer presence on the root dentin walls was a limiting factor to dye penetration (Permeability Index), in middle third for manual irrigation.MestradoOdontopediatriaMestre em Odontologi

Aesthetic And Functional Rehabilitation Of The Primary Dentition Affected By Amelogenesis Imperfecta.

The objective of this case report was to describe the oral rehabilitation of a five-year-old boy patient diagnosed with amelogenesis imperfecta (AI) in the primary dentition. AI is a group of hereditary disorders that affects the enamel structure. The patient was brought to the dental clinic complaining of tooth hypersensitivity during meals. The medical history and clinical examination were used to arrive at the diagnosis of AI. The treatment was oral rehabilitation of the primary molars with stainless steel crowns and resin-filled celluloid forms. The main objectives of the selected treatment were to enhance the esthetics, restore masticatory function, and eliminate the teeth sensitivity. The child was monitored in the pediatric dentistry clinic at four-month intervals until the mixed dentition stage. Treatment not only restored function and esthetic, but also showed a positive psychological impact and thereby improved perceived quality of life. The preventive, psychological, and curative measures of a young child with AI were successful. This result can encourage the clinicians to seek a cost-effective technique such as stainless steel crowns, and resin-filled celluloid forms to reestablish the oral functions and improve the child's psychosocial development.201579089

Morphological And Chemical Changes In Dentin After Using Endodontic Agents: Fourier Transform Raman Spectroscopy, Energy-dispersive X-ray Fluorescence Spectrometry, And Scanning Electron Microscopy Study.

We examine the morphological and chemical changes in the pulp chamber dentin after using endodontic agents by scanning electron microscopy (SEM), Fourier transform Raman spectroscopy (FT-Raman), and micro energy-dispersive x-ray fluorescence spectrometry (μEDXRF). Thirty teeth were sectioned exposing the pulp chamber and divided by six groups (n=5): NT-no treatment; CHX-2% chlorhexidine; CHXE-2% chlorhexidine+17% EDTA; E-17% EDTA; SH5-5.25% NaOCl; SH5E-5.25% NaOCl+17% EDTA. The inorganic and organic content was analyzed by FT-Raman. μEDXRF examined calcium (Ca) and phosphorus (P) content as well as Ca/P ratio. Impressions of specimens were evaluated by SEM. Data were submitted to Kruskal-Wallis and Dunn tests (pNT=SH5E>CHX>E>CHXE). CHXE and E presented the highest Ca/P ratio values compared to the other groups (p<0.05). The SEM images in the EDTA-treated groups had the highest number of open tubules. Erosion in the tubules was observed in CHX and SH5E groups. Endodontic agents change the inorganic and organic content of pulp chamber dentin. NaOCl used alone, or in association with EDTA, was the most effective agent considering chemical and morphological approaches.1707500

Color stability and gloss of esthetic restorative materials after chemical challenges

This study evaluated gloss and color changes of esthetic restorative materials subjected to different acidic beverages. Specimens of resin composites (Z350XT (Z350), IPS Empress Direct (ED), Charisma Diamond (CD)) were prepared and the initial surface gloss and color (ΔE) were measured (n=10). Then, the specimens were immersed in 4 mL of each of the different beverages (cranberry juice; Coca-Cola; coffee or artificial saliva) during 15 min, 3x/day for 14 days and new gloss and color readings were obtained. Color change was evaluated with the ΔE formula and gloss change values were obtained by the formula: (final gloss - initial gloss). Data was submitted to two-way ANOVA followed by Tukey’s post hoc test (a=0.05). CD showed the lowest color change among resin composites. The highest ΔE values were obtained after immersion in coffee and cranberry juice. Coffee promoted the highest gloss change (worst gloss retention), followed by cranberry juice, Coca-cola and artificial saliva (p<0.05). The type of beverage significantly influenced the gloss of resin composites. Coca-cola reduced gloss of the three resin composites in a similar manner. Coffee affected the ED gloss more than that of Z350 and CD, while cranberry juice affected Z350 more than ED and CD. Saliva had a more pronounced effect on the gloss retention of CD than ED. The beverages used in this study influenced the optical surface properties of the composites studied301525

Influence of environmental conditions on properties of ionomeric and resin sealant materials

OBJECTIVES: The aim of this study was to determine the effect of environmental conditions on the degradation of ionomeric and resin sealant materials. MATERIAL AND METHODS: FluroShield, Vitremer, and Ketac Molar disc-shaped specimens (n=18/material) were prepared, polished, subjected to initial hardness and roughness readings. Six discs of each material were randomly assigned to one of three different storage solutions: 0.3% citric acid (CA), demineralization solution (DE), and remineralization solution (RE). The specimens were individually immersed in 3 mL of the test solutions, which were daily changed. After 15 days of storage, new surface roughness and hardness readings were done. Fluoride release in the solutions was measured within 15 days. Data were analyzed by ANOVA and Tukey's and Contrast tests (&#945;=0.05). RESULTS: The storage in CA increased the roughness of Vitremer and Ketac Molar. A significant reduction in hardness was observed for all materials after storage in all solutions. For all materials, the greatest amounts of fluoride release occurred during the 1st day. FluroShield presented the same patterns of fluoride release in all solutions. Ketac Molar and Vitremer released the highest amounts of fluoride in the CA solution. CONCLUSIONS: Ionomeric materials are more susceptible to degradation than resin-based materials under acidic conditions. Acidic conditions lead to a higher fluoride release from ionomeric materials

Revisão crítica sobre o grau de conversão de monômeros resinosos detectados por métodos de análise direta

Objectives: The aim of this study was to carry out\ud a review on the methods of direct detection of the\ud conversion degree of composite resins. Materials &\ud methods: The authors searched the Cochrane Library,\ud Embase, PubMed, and the Web of Science (ISI) for\ud papers dated from January 1991 to November 2011.\ud The search was complemented by manual searches of\ud the reference lists from each identified relevant paper.\ud The main search terms were: “degree of conversion”,\ud “monomers”, “polymers”, “composite”, “pre-gel”,\ud “post-gel”, “residual monomers” and “double bond”.\ud The inclusion criteria were studies that evaluated\ud consolidated methods in the literature to directly\ud evaluate the degree of conversion. Excluded studies\ud were those considered to be unrelated to the\ud question addressed, such as mechanical and physical\ud properties and also monomers from adhesive systems\ud and compomers. The selected papers were assigned\ud to a score (A, B or C), according to the predetermined\ud criteria. Results: A total of 45 papers were selected\ud and 15 papers were included in the critical appraisal.\ud Two articles were labeled as grade A, nine articles\ud were labeled as grade B, and four articles were\ud labeled as grade C. Conclusions: According to the\ud definitions of evidence levels, the current article\ud study showed a strong evidence of review. Clinical\ud significance: The degree of conversion predicts the\ud quality of polymers because the higher degree of\ud conversion, the higher strength of the resin matrix.Objetivos: O objetivo deste estudo foi revisar os métodos\ud de detecção direta do grau de conversão de resinas\ud compostas. Material e Métodos: Os autores pesquisaram\ud artigos publicados no período de Janeiro de 1991 a\ud novembro de 2011, nas bases de dados Cochrane Library,\ud Embase, PubMed e Web of Science (ISI). A pesquisa\ud foi complementada por pesquisa manual das listas de\ud referências de cada artigo identificado como relevante\ud sobre o tema. Os principais termos pesquisados foram:\ud “grau de conversão”, “monômeros”, “polímeros”, “compósito”,\ud “pré-gel”, “pós-gel”, “monômeros residuais” e\ud “dupla ligação”. Os critérios de inclusão foram estudos\ud que avaliaram diretamente o grau de conversão utilizando\ud métodos consolidados na literatura. Os estudos\ud excluídos foram aqueles considerados não relacionados\ud à questão abordada, como estudos sobre propriedades\ud físicas e mecânicas e também sobre monômeros de sistemas\ud de união e compômeros. Os artigos selecionados\ud foram divididos na classificação A, B ou C, de acordo\ud com critérios pré-determinados. Resultados: Quarenta\ud e cinco artigos foram selecionados e quinze artigos\ud foram incluídos na avaliação. Dois artigos foram classificados\ud como grade A, nove artigos como grade B e\ud quatro artigos como grade C. Conclusões: De acordo\ud com as definições dos níveis de evidência, o presente\ud estudo apresentou forte evidência de revisão. Significância\ud Clínica: O grau de conversão prediz a qualidade\ud dos polímeros formados, uma vez que quanto maior o\ud grau de conversão, mais resistente é a matriz resinosa

Permeabilidade dentinária radicular em dentes decíduos : soluções e métodos de irrigação

Devido à escassez de literatura e a importância de se realizar adequadamente a técnica endodôntica em dentes decíduos, no que diz respeito à permeabilidade da dentina radicular, esse estudo tem por objetivo discutir a efetividade de algumas substâncias irrigadoras, como por exemplo, substâncias halógenas, quelantes, peróxidos, associações e misturas, e a influência de dois sistemas de irrigação utilizados durante a instrumentação endodôntica de dentes decíduos (manual e por vibração ultra-sônica) em relação às alterações na permeabilidade dentinária. Baseado na revisão de literatura pôde-se concluir que dentre as soluções empregadas em dentes permanentes, todas as soluções e associações estudadas produziram aumento da permeabilidade dentinária. De uma maneira geral, não houve diferença quanto à permeabilidade dentinária entre a instrumentação ultra-sônica e manual. Não há trabalhos de pesquisa realizados em dentes decíduos em quantidade suficiente para que se estabeleça definitivamente os padrões para aumento da permeabilidade dentinária dos condutos radiculares em relação às soluções irrigadoras e métodos de irrigação.Due to the little material available in the literature and to the importance in adequately accomplish the endodontic technique in primary teeth regarding the radicular dentin permeability, the aim of this study is to discuss the efficacy of some irrigate substances, as well as the influence of two irrigation systems used during endodontic preparation of primary teeth (manual or in ultra sonic vibration) regarding the changes in dentinal permeability. Based on the literature review it could be concluded that, among the solutions employed in permanent teeth, all solutions and associations studied herein increased the dentinal permeability. There was no difference in the dentinal permeability when comparing manual and ultra sonic preparation. There are not enough papers focusing primary teeth in this subject to definitely establish the patterns of dentinal permeability increase in tooth root canal regarding the irrigating solutions and irrigation systems