Características histológicas da lesão inicial da cárie secundária adjacente a restaurações de resina composta

The aim of this study was to analyse morphologically the initiation of the secondary caries lesion. Thirty-three proximal surfaces adjacent to Class II resin restorations were examined by stereomicroscope (x40) for the presence of caries and gap. Sixty sites (39 sound, 7 with lesions, 14 adjacent to lesions) were prepared for examination using polarized light microscopy in water and after air drying. Lesions were observed in 52.7% of the wet sections and 85.0% of the dried sections. The dried ground sections displayed larger lesions. Further analyses were performed on the dried sections. One hundred per cent of the ground sections from the stereomicroscope carious sites, 87.2% from sound sites, and 71.4% from sites adjacent to lesions displayed demineralized areas. Morphological analysis indicated that caries lesion initiates at the external enamel surface in the interface between tooth and restoration. Two distinct patterns of caries development were observed, related to the direction of enamel rods: (1) the direction of the rods in the adjacent enamel was parallel to the cavity wall (the deepest part of caries penetration was located at the cavity wall), and (2) the direction of the rods ran in the apical direction (the deepest part of caries penetration was oblique to the cavity wall). The pattern 1 could be mistaken for a wall lesion. The prevalence of lesions adjacent to restorations was similar in the sites with (85.7%) and without (84.0%) gaps. The findings support the assumption that secondary caries initiation in vivo is not related to the presence of a gap and follows the direction of the enamel rods.O objetivo deste estudo foi analisar morfologicamente o início da lesão de cárie secundária. Trinta e três superfícies proximais adjacentes a restaurações de resina classe II foram examinadas ao estereomicroscópio (40x) para a presença de carie e gap. Sessenta sítios (39 sadios, 7 com lesões, 14 adjacentes a lesões) foram preparados para exame utilizando microscopia de luz polarizada. As lesões foram observadas em 52,7% dos corte úmidos e 85,0% dos cortes secos. Os cortes secos demonstraram lesões maiores. Analises posteriores foram realizadas nos cortes secos. Cem por cento das secções observadas no estereomicroscópio, 87,2% das lesões hígidas, e 71,4% dos sítios adjacentes a lesões demonstraram áreas desmineralizadas. A análise morfológica indicou que a lesão cariosa inicia na superfície de esmalte externa na interface entre dente e restauração. Dois padrões distintos de desenvolvimento de carie foram observados, relacionados à direção dos prismas de esmalte: (1) a direção dos prismas no esmalte adjacente foi paralela à parede da cavidade (a parte mais profunda da penetração da cárie foi localizada na parede da cavidade), e (2) a direção dos prismas corria na direção apical (a parte mais profunda da penetração da cárie foi obliqua à parede da cavidade). O padrão 1 pode ser confundido por uma parede da lesão. A prevalência de lesões adjacentes às restaurações foi similar em sítios com (85,7%) e sem (84,0%) gaps. Os achados suportam o pressuposto de que o inicio da lesão de cárie secundária in vivo não está relacionado à presença de um gap e segue a direção dos prismas de esmalte

Características da cárie secundária adjacente a restaurações de resina composta

The aim of this study was to analyze the features of secondary caries and their relationship with the presence of restorations marginal defects as gap, negative ledge (NL, lack of restorative material) and positive ledge (PL, overhang). Eighty proximal surfaces of Class II resin restorations were photographed and analyzed using a stereomicroscope (X40). It was recorded the presence of external secondary caries, gap, NL, PL and after the restorations removal, the presence of internal lesion. All the exams were done in 10 well-defined points. The reproducibility (Kappa Index) of the exams of external caries, presence of gaps, restorations marginal defects and internal caries were, respectively: 0.88 e 0.94; 0.80 e 0.87; 0.83 e 0.90 e 0.82 e 0.94. As reprodutibilidades (Kappa) dos exames de cárie externa, EDR, presença de degraus e cárie interna no início e depois da análise de 50% da amostra foram, respectivamente: 0,88 e 0,94; 0,80 e 0,87; 0,83 e 0,90 e 0,82 e 0,94. The prevalence of secondary caries (p < 0.05) and gap (p < 0.01) were associated with gingival margin. The restorations marginal defects (NL and PL) were not associated with any specific location (buccal, lingual or gingival) (p= 0.073). It was observed a relationship between these defects with secondary caries prevalence (gap: p= 0.004; NL and PL: p= 0.017). This association could be explained by the biofilm accumulation usually observed in the interface tooth surface/ restoration marginal defects. The presence of internal lesion was associated with external lesion (p< 0.001). Although, in 141 points was observed internal lesion without the presence of external lesion. The majority of these lesions showed internal enamel involvement. Only 8% had emineralization restricted to dentine, which could suggest residual caries. The results of this study showed that secondary caries lesion frequently began externally on the interface tooth/restoration, where diagnose, control and arrestment of the lesions is possible.Objetivo: O objetivo deste estudo foi analisar as características de cárie secundária e sua relação com a presença de restaurações com defeitos marginais como gap, degrau negativa (NL, a falta de material restaurador) e degrau positiva (PL, saliência). Materiais e Métodos: Oitenta superfícies proximais de restaurações de resina classe II foram fotografados e analisados utilizando um microscópio estereoscópico (X40). Foi registrada a presença de cáries secundárias externas, gaps, NL, PL e após a remoção de restaurações, a presença de lesão interna. Todos os exames foram realizados em 10 pontos bem definidos. Resultados: A prevalência de cárie secundária e gap foram associados com margem gengival. As restaurações com defeitos marginais (NL e PL) não foram associados a qualquer local específico (vestibular, lingual ou gengival). Observou-se uma relação entre esses defeitos com a prevalência de cárie secundária. A presença da lesão interna foi associada com lesão externa. Embora, em 141 pontos foi observada lesão

Amalgam versus resin composite for the restoration of posterior teeth: disparities between public clinical practice and dental education in southern Brazil

Objetivo: Comparar o material restaurador indicado no tratamento de dentes posteriores de acordo com o ensino e realização dos tratamentos em duas Faculdades de Odontologia (UFRGS e ULBRA) e em 8 unidades básicas de saúde (UBS) do Sistema de Saúde Pública em Porto Alegre, Brasil. Materiais e Métodos: Os dados referentes ao ensino de procedimentos restauradores utilizando amálgama (AM) ou resina composta (RC) foram obtidos através da análise de prontuários de pacientes a questionários aplicados aos estudantes de Odontologia do último ano. Informações sobre os procedimentos restauradores nas UBS foram obtidas através de prontuários de pacientes e de questionários aplicados aos dentistas. O tipo de material restaurador utilizado nas Faculdade de Odontologia e nas UBS foram comparados através de teste Qui-quadrado. Resultados: Na UFRGS, 327 restaurações foram realizadas, sendo 78,28% RC e 21,72% AM; na ULBRA, 366 restaurações foram efetuadas, sendo 92,63% RC e 7,37% AM. Nas UBS, 1664 restaurações foram realizadas, sendo 35,93% RC e 64,07% AM. Uma maior proporção de restaurações de AM foram realizadas no Serviço Público de Saúde em comparação às Faculdades de Odontologia, nas quais restaurações com RC foram mais prevalentes (p=0.000). Conclusões: A mudança de AM para RC na escolha do material restaurador para dentes posteriores em Faculdades de Odontologia não foi seguida pelo Sistema Público de Saúde, onde o AM ainda é largamente utilizadoPurpose: To compare the restorative material used in the treatment of posterior teeth taught and performed in two Dental Schools (UFRGS and ULBRA) and in 8 basic health units (BHU) from the Public Health System in Porto Alegre, Brazil. Materials and methods: Data referring the teaching of restorative procedures using amalgam (AM) or resin (R) were obtained through the analysis of patient’s files and questionnaires applied to final year dental students. Information regarding restorative procedures at BHU was obtained through patient’s records and a questionnaire applied to the dentists. The type of restorative material used in both BHU and Dental Schools were compared by chi-square test. Results: At UFRGS, 327 restorations were performed, 78.28% R and 21.72% AM, and at ULBRA 366 restorations, 92.63% R and 7.37% AM. At BHU, 1664 restorations were performed (35.93% R and 64.07% AM). A major proportion of AM restorations was performed in the Public Health Service in comparison to both Dental Schools, in which resin restorations prevailed (p=0.000). Conclusion: The change from AM to R in the dental material choice for posterior teeth at Dental Schools was not followed by the Public Health System, where the AM is still widely used in posterior teeth

Amálgama versus resina composta para restaurações de dentes posteriores: Diferenças entre a prática clínica no Serviço Público e o ensino em faculdades de Odontologia no sul do Brasil

Purpose: To compare the restorative material used in the treatment of posterior teeth taught and performed in two Dental Schools (UFRGS and ULBRA) and in 8 basic health units (BHU) from the Public Health System in Porto Alegre, Brazil. Materials and methods: Data referring the teaching of restorative procedures using amalgam (AM) or resin (R) were obtained through the analysis of patient’s files and questionnaires applied to final year dental students. Information regarding restorative procedures at BHU was obtained through patient’s records and a questionnaire applied to the dentists. The type of restorative material used in both BHU and Dental Schools were compared by chi-square test. Results: At UFRGS, 327 restorations were performed, 78.28% R and 21.72% AM, and at ULBRA 366 restorations, 92.63% R and 7.37% AM. At BHU, 1664 restorations were performed (35.93% R and 64.07% AM). A major proportion of AM restorations was performed in the Public Health Service in comparison to both Dental Schools, in which resin restorations prevailed (p=0.000). Conclusion: The change from AM to R in the dental material choice for posterior teeth at Dental Schools was not followed by the Public Health System, where the AM is still widely used in posterior teeth.Objetivo: Comparar o material restaurador indicado no tratamento de dentes posteriores de acordo com o ensino e realização dos tratamentos em duas Faculdades de Odontologia (UFRGS e ULBRA) e em 8 unidades básicas de saúde (UBS) do Sistema de Saúde Pública em Porto Alegre, Brasil. Materiais e Métodos: Os dados referentes ao ensino de procedimentos restauradores utilizando amálgama (AM) ou resina composta (RC) foram obtidos através da análise de prontuários de pacientes a questionários aplicados aos estudantes de Odontologia do último ano. Informações sobre os procedimentos restauradores nas UBS foram obtidas através de prontuários de pacientes e de questionários aplicados aos dentistas. O tipo de material restaurador utilizado nas Faculdade de Odontologia e nas UBS foram comparados através de teste Qui-quadrado. Resultados: Na UFRGS, 327 restaurações foram realizadas, sendo 78,28% RC e 21,72% AM; na ULBRA, 366 restaurações foram efetuadas, sendo 92,63% RC e 7,37% AM. Nas UBS, 1664 restaurações foram realizadas, sendo 35,93% RC e 64,07% AM. Uma maior proporção de restaurações de AM foram realizadas no Serviço Público de Saúde em comparação às Faculdades de Odontologia, nas quais restaurações com RC foram mais prevalentes (p=0.000). Conclusões: A mudança de AM para RC na escolha do material restaurador para dentes posteriores em Faculdades de Odontologia não foi seguida pelo Sistema Público de Saúde, onde o AM ainda é largamente utilizad

Availability and stability of soluble fluoride content in commercial fluoride dentifrices available in Uruguay

The aim of this study was to evaluate the availability and stability of soluble fluoride fraction in commercial fluoride toothpastes available in Uruguay. Methods: Fourteen fluoride toothpastes from four different manufacturers were analyzed. Randomized and blinded analyses were performed in duplicate for each dentifrice at the time of purchase (fresh samples) and after 12 months of storage at room temperature (aged samples). Total fluoride and total soluble fluoride concentrations were measured using a fluoride specific electrode. Results: Total fluoride concentrations in all of the products were lower than the F levels specified by the manufacturers. Total soluble fluoride fractions were lower than the total fluoride concentrations in fresh samples of five toothpastes and in aged samples of ten toothpastes (p < 0.05). Three toothpastes had insufficient and unstable total soluble fluoride fractions (< 60%) and five toothpastes had only unstable total soluble fluoride fractions (<1000 ppm) after 12 months. Conclusion: Based on the results of this study, it can be concluded that from fourteen Uruguayan commercial fluoride toothpastes analyzed in this study, three toothpastes have insufficient and unstable chemically active F fractions and five other toothpastes have the lack of stability which may compromise their efficacies. Review the guidelines on fluoride dentifrices in Uruguay is necessary, in order to ensure optimum benefit for population

Prevalência de cárie, gengivite e fluorose em escolares de 12 anos de Porto Alegre - RS, Brasil, 1998/1999

The aim of the study was to evaluate the prevalence of dental caries, gingival bleeding and fluorosis in twelve-year-old schoolchildren from Porto Alegre, Brazil. One thousand students from private and public schools were examined. The indexes used were BI, DMF and TFI. The data pertaining to BI were the first to be collected. After that, the children were submitted to plaque removal and their teeth were dried prior to the examination for caries and fluorosis. The average value for DMFT, including cavitated and non-cavitated lesions, was 2.22 ± 0.08 (standard error). The average value for BI was 19.76% ± 0.54% (standard error) and the prevalence of students with fluorosis was 52.9%. Regarding the severity of fluorosis, 45.9% of the children had TFI 1, 6.1% TFI 2 and 0.9% TFI 3. A polarization of the experience of caries and gingivitis was observed in the studied population. Only 14.4% of the students had DMFS higher than 7. A small percentage of children (12%) presented with BI ³ 40%. The experience of caries and gingivitis of 12-year-old schoolchildren in Porto Alegre is comparable to that of children from developed countries. That probably results from the intense utilization of fluoride, which is also causing an increased prevalence of fluorosis. The severity of fluorosis does not justify any public health measure. The results show that the employed public health measures are effective, although part of the population still needs additional care.O objetivo do estudo foi avaliar a prevalência de cárie, gengivite e fluorose em escolares de 12 anos de Porto Alegre - RS. Foram examinados 1.000 escolares da rede de ensino público e particular da cidade. Os índices utilizados foram o ISG, CPO e o ITF. Após a coleta do ISG, a criança foi submetida à remoção da placa e secagem dos dentes para proceder-se aos exames de cárie e fluorose. A média e erro padrão do CPOD, incluindo as lesões não cavitadas, foi de 2,22 ± 0,08, o ISG foi de 19,76% ± 0,54% e a prevalência de escolares com fluorose foi de 52,9%. Em relação à severidade, 45,9% das crianças apresentaram ITF 1, 6,1%, ITF 2 e 0,9%, ITF 3. Os escolares com CPOS maior que 7 (51,2%) compreenderam 14,4% da amostra. Quanto ao sangramento gengival, observou-se que 12% das crianças apresentavam ISG >; ou = 40%. O CPOD de Porto Alegre é comparável ao de países desenvolvidos, resultado provavelmente em decorrência do uso intensivo de flúor, que também está ocasionando a fluorose. A severidade da fluorose encontrada não justifica qualquer medida de saúde pública. As medidas de saúde pública de impacto populacional estão sendo efetivas, porém, existe uma parcela da população que necessita de cuidados adicionais

Genotypic Diversity and Virulence Traits of Streptococcus mutans

The aim of this study was to compare the genotypic diversity and virulence traits of Streptococcus mutans isolated from carious dentin before and after partial dentin caries removal (PDR) and sealing. Carious dentin samples were obtained three months before and after the PDR and cavity sealing. Up to seven isolates of each morphological type of S. mutans were selected and strain identity was confirmed using gtfB primer. Genotyping was performed by arbitrary primer-PCR (AP-PCR). Acidogenesis and acidurance of the genotypes were evaluated as virulence traits. A paired t-test and a Wilcoxon test were used to compare the virulence of genotypes. A total of 48 representative S. mutans isolates were genotyped (31 before and 17 after the sealing). At least one of the genotypes found before the sealing was also found on dentin after the sealing. The number of genotypes found before the sealing ranged from 2 to 3 and after the sealing from 1 to 2 genotypes. No difference was observed in the acidogenesis and acidurance between genotypes isolated before and after the sealing. In conclusion, genotypic diversity of S. mutans decreased after the PDR and sealing, but the virulence traits of S. mutans remained unchangeable