New possibilities of management and monitoring of caries lesions on approximal surfaces

Objetivos: Este trabalho é composto de seis estudos que têm como objetivos avaliar: (1) a eficácia de métodos caseiros e profissionais na limpeza de faces proximais intactas e com cavidade, em contato, (2) e após simulação da separação dentária; (3) a fluorescência intrínseca de materiais seladores e a capacidade desses materiais em bloquear a fluorescência do substrato subjacente; (4) o desempenho do exame de fluorescência a laser (FL) em detectar e quantificar lesões proximais de cárie em molares decíduos sob materiais seladores; (5) verificar a microinfiltração e capacidade de penetração do selante em lesões proximais com cavidade; e (6) avaliar clinicamente o sucesso do selamento proximal quando comparado ao tratamento restaurador convencional. Materiais e Métodos: Para os objetivos (1) e (2), oito pares de molares decíduos foram utilizados na avaliação da eficácia dos métodos de limpeza proximal. Para isso, dois dispositivos foram idealizados, um que simulava o contato proximal dos dentes e o outro que mimetizava a separação dentária com o espaço entre as faces proximais de 0,5 mm. Um marcador em spray foi aplicado nas faces proximais e os métodos foram realizados. Todos os métodos foram testados nos mesmos dentes, após total remoção do corante e nova aplicação do mesmo. Após o teste de cada método, as faces foram fotografadas em lupa e analisadas. Para o objetivo (3), cavidades padronizadas de 0,5 e 1 mm confeccionadas em placas de acrílico transparentes e preenchidas com diferentes materiais resinosos foram utilizadas na avaliação da fluorescência intrínseca e capacidade de bloqueio de fluorescência destes materiais. As cavidades foram medidas com o DIAGNOdent pen quando vazias (baseline) e logo depois de preenchidas. As medições foram repetidas 24h, uma semana e um mês após o preenchimento. Já para o objetivo (4), trinta molares decíduos com lesões de cárie proximais sem cavidade foram selecionados para a avaliação da influência de um selante e de um adesivo dentinário na detecção destas lesões. Para isso, os dentes foram montados em um dispositivo que permitiu o contato proximal, e as faces com lesões foram medidas com o DIAGNOdent pen após limpeza 11 (baseline) e logo após a aplicação do material. As medições foram repetidas 24h, uma semana e um mês após o selamento. Ao final, os dentes foram seccionados e analisados quanto à presença e profundidade da lesão de cárie. No objetivo (5), quarenta e cinco molares decíduos e quarenta molares permanentes com lesões de cárie proximais com cavidade (ICDAS 3, 4 ou 5) foram usados para avaliar a microinfiltração e habilidade de penetração de dois materiais seladores, com ou sem aplicação prévia de adesivo dentinário. Após o selamento, os dentes sofreram termociclagem (1000 ciclos) e microinfiltração com azul de metileno a 2% por 24h. Posteriormente os dentes foram seccionados e a microinfiltração e capacidade de penetração avaliadas. Para o objetivo (6), um estudo piloto in vivo comparou o sucesso do selamento de lesões de cárie proximais com cavidade em molares decíduos quando comparado ao tratamento restaurador convencional com resina composta. Foram incluídas 8 crianças com 22 lesões proximais, das quais 13 foram seladas e 9 foram restauradas após randomização simples por sorteio. Todas as lesões foram acompanhadas clinica e radiograficamente por 18 meses. Resultados: (1) Em molares decíduos em contato, o fio dental foi o método mais eficaz na área de interesse, removendo 83,1% do marcador. Nas ameias, a escova dental apresentou os melhores resultados, com remoção muito próxima a 100%. (2) Em molares decíduos simulando a separação temporária, as escovas interproximais média e grande foram capazes de remover a maior quantidade de marcador da área de interesse. A escova de Robinson se mostrou mais eficaz, removendo entre 84 e 100% do marcador das ameias e se estendendo à área abaixo do ponto de contato, removendo 48,2% do marcador. Os métodos falharam em remover placa do interior da cavidade. Mesmo com a separação temporária, as escovas interproximais maiores que o espaço removeram no máximo 20% do marcador. (3) Nas placas de acrílico, o adesivo dentinário de dois frascos apresentou-se mais estável, apresentando menos alterações de fluorescência intrínseca nas medições realizadas até um mês após o selamento e exercendo menor influência nas medições da fluorescência da superfície subjacente. Entre os selantes, o material transparente e com 58% de carga apresentou os resultados mais aceitáveis. (4) Nas lesões de mancha branca em molares decíduos seladas com o adesivo dentinário de dois frascos, as leituras de FL demonstraram boa correlação com a profundidade da lesão, verificada histologicamente. (5) No selamento de lesões proximais com cavidade em dentes permanentes e decíduos, o uso de uma camada intermediária de adesivo dentinário e a quantidade de carga do selante não exerceram 12 influência na microinfiltração e na capacidade de penetração dos materiais na cavidade. As lesões ICDAS 5 demonstraram menor capacidade serem preenchidas, quando comparadas às lesões de ICDAS 3 e 4. (6) No estudo in vivo, após 18 meses, 69,2% dos selantes havia falhado, contra 11,1% das restaurações, diferença que se mostrou estatisticamente significante. Com relação à progressão da lesão, 53,8% das lesões seladas progrediram, contra 11,1% das restaurações. Conclusões: Em lesões de cárie proximais com cavidade, métodos de limpeza interproximal falharam em remover a placa do interior da cavidade. Já em lesões sem cavidade, a escovação diária, pela técnica de Fones, associada ao uso do fio dental se mostrou a maneira mais eficaz de remover efetivamente o biofilme das faces proximais de molares decíduos. Os métodos de limpeza interproximal mais indicados na profilaxia das faces proximais pré-selamento em lesões de cárie com ou sem cavidade são a escova de Robinson associada a uma escova interproximal de diâmetro maior que o espaço obtido após a separação temporária. No selamento de manchas brancas, o adesivo dentinário de dois frascos permitiu uma correlação das leituras de FL com a profundidade das lesões, por apresentar menos alterações de fluorescência intrínseca com o envelhecimento e exercer menor influência nas medições da fluorescência da superfície subjacente, podendo assim, ser indicado no selamento de lesões iniciais de cárie proximal a serem controladas pelo o método de FL. Entretanto, quando um material com carga se faz necessário, selantes com opacificadores devem ser evitados, por exercerem maior influência nas medições da FL. No selamento de lesões proximais com cavidade, o uso de uma camada intermediária de adesivo dentinário e a quantidade de carga do selante não exerceram influência na microinfiltração e na capacidade de penetração dos materiais na cavidade, nos dentes decíduos e permanentes. O estudo clínico sugere que o selamento não é uma alternativa viável no tratamento de lesões proximais de cárie com cavidade, por apresentar maior tendência a falhas e ao insucesso.Aim: This thesis is composed of six studies, which aimed at evaluating (1) the efficacy of prophylaxis methods used, professionally and at home, on approximal surfaces, in contact with the adjacent tooth, (2) and after simulation of tooth separation; (3) the intrinsic fluorescence of sealing materials and their ability of these materials to clock the fluorescence of the underlying surface; (4) the performance of a laser fluorescence (LF) device in detecting and quantifying approximal caries in primary molars under the sealant; (5) access the microleakage and penetration ability of sealing materials on cavitated approximal lesions; and (6) access, in vivo, the success rate of approximal sealant when compared to the conventional restorative procedure. Materials and Methods: For the aims (1) and (2), eight pairs of primary molars were used to evaluate the efficacy of prophylaxis methods on approximal surfaces. For that, two dispositives were idealized, one allowed the teeth to be in approximal contact and the other aimed to mimic the temporary tooth separation, which a 0,5mm space between the approximal surfaces. A marker, in form of spray, was applied on the approximal surfaces and the different methods were applied. All methods were tested on the same teeth, after complete removal of the marker and its re-application. Afterwards, the surfaces were photographed by an optic microscope and analyzed. For the aim (3), standardized cavities of 0,5 and 1 mm in depth, bored in clear acrylic boards and filled with different resinous materials, were used to evaluate their intrinsic fluorescence and their ability to block the fluorescence of the underlying surface. The cavities were accessed by the LF device (DIAGNOdent pen - DDpen) when empty, and right after filling. The subsequent measurements were done at 24 hrs, one week and one month after filling. For the aim (4), thirty primary molars with non-cavitated approximal caries lesions, scored ICDAS 1 and 2, were chosen for the evaluation of the influence of a fissure sealant and a dental adhesive on the detection of these lesions. For that, the teeth were mounted in a dispositive, which allows a close approximal contact, and the surfaces with caries were measured with the DDpen after cleaning (baseline) and right after sealing. The 14 measurements were repeated after 24 hrs, one week and one month. The teeth were, afterwards, sectioned and their histopathology analyzed. For the aim (5), forty-five primary molars and forty permanent molars with cavitated approximal caries lesions, scored ICDAS 3, 4 or 5, were sealed with or without an adhesive intermediate layer. After sealing, the teeth were thermocycled (1000 cycles) and inserted in methylene blue 2% for 24 hrs. Afterwards, the teeth were sectioned and microleakage and penetration ability were accessed. For the aim (6), an in vivo pilot study, which assessed the success rate of approximal sealant on cavitated lesions compared to the conventional restorative treatment. Eight children, aged 5-9 years, with 22 cavitated approximal lesions, were included in this study. Lesions treatment was raffled by the children, and therefore, 13 lesions were sealed and 9 were restored. All lesions were controlled radiograph and clinically up to 18 months. Results: (1) In primary molars in approximal contact, the dental floss was the most efficient method on cleaning the area of interest, removing 83,1% of the marker. On the buccal and lingual interdental spaces, the toothbrush presented the best results, removing approximately 100% of the marker. (2) On primary molars simulating tooth temporary separation, the median and large interdental brushes were able to remove more marker from the area of interest. The flat bristle brush was the most effective method, removing 84-100% of the marker from the buccal and lingual interdental spaces, and extending its efficacy to the area under the contact point, removing 48,2% of the marker. All methods failed at removing the marker from the cavity. Even with the tooth separation, the interdental brushes removed the marker to a maximum of 20%. (3) On the acrylic boards, the two-bottle dental adhesive was more stable, exhibiting less intrinsic fluorescence alterations on the reading up to one month after sealing, and influencing the least the measurement of the underlying surfaces fluorescence. Among the fissure sealants, the clear and highly filled material presented the most acceptable results. (4) On non-cavitated approximal lesions in primary molars sealed with the two-bottle dental adhesive, the LF reading showed a good correlation to lesion depth, histologically accessed. (5) On the sealing of cavitated approximal lesions in permanent and primary molars, the use of an adhesive intermediate layer and the filler content of the sealant did not influence the microleakage and penetration ability into the cavities. Lesions ICDAS 5 were less filled than lesions ICDAS 3 or 4. (6) On the in vivo study, after 18 months, 69,2% of the approximal sealants have failed, against to 11,1% of the restorations. This difference was shown to be statistically significant. Regarding progression, 53,8% of sealed 15 lesions have progressed, against 11,1% of the restored ones. Conclusions: In cavitated approximal caries lesions, the prophylaxis methods failed to remove the marker from the cavity. In non-cavitated lesions, the daily tooth brushing, by Fones method, associated with flossing, was shown to be the most efficacious method of removing effectively the biofilm from the approximal surfaces. The most efficacious methods indicated to the pre-sealing prophylaxis on approximal surfaces with or without cavitation are the flat bristle brush associated with an interdental brush larger than the space obtained after tooth separation, in diameter. On the approximal sealant of non-cavitated lesions, the two-bottle dental adhesive allowed a better correlation between LF readings and lesion depth, for exhibiting less intrinsic fluorescence alterations with aging and for exerting less influence on LF measurements from the underlying surface, and therefore, can be indicated for approximal sealant on non-cavitated lesions to be controlled by the LF method. However, when a filled material is needed, sealants with opacifiers should be avoided. When sealing cavitated lesions, the use of an adhesive intermediate layer and a highly filled sealant did not contribute to a decrease in microleakage and in an increase of penetration ability into the cavities. The in vivo study suggests that the sealant is not a viable alternative for the treatment of cavitated approximal lesions, for exhibiting higher failure rates

Penetration ability and microleakage of a fissure sealant applied on artificial and natural enamel fissure caries

OBJECTIVES AND METHODS: This study investigated the sealing ability of a current available unfilled fissure sealant applied over sound (n=80), artificially created (n=80) and naturally carious fissures (n=80) under different humidity conditions (90+/-2 and 45+/-2% relative humidity) and etching times (40 and 60s). All samples were submitted to 5000 thermal cycles and examined by light microscopy after sectioning. Microleakage, penetration ability, fissure type, fissure entrance angle, sealant occlusal length, caries location and caries depth were assessed. RESULTS: The significantly longer sealant occlusal length and larger entrance angle exhibited by shallow fissures, contributed to their higher microleakage and smaller amounts of unfilled areas compared to deep fissures. Sealant microleakage was significantly influenced by the condition of the enamel (sound, artificial and natural caries) and the caries location in the fissures, but not by enamel caries depth (D1 and D2), etching time, or humidity condition. Natural caries exhibited significantly higher microleakage than sound or artificially created carious fissures. CONCLUSIONS: Based on the results of this study, it can be concluded that location of caries in the fissure rather than its depth should be taken into account when applying a fissure sealant. When the borders of the fissure sealant are on carious enamel, a significantly higher microleakage must be expected. The artificial caries model was not a suitable method to assess the behavior of natural fissure caries

The impact of ozone treatment on enamel physical properties

PURPOSE: To assess the effects of the highly reactive molecule of ozone on sound enamel physical properties and its effects on sealing ability. METHODS: The effect of ozone on sealant tag length, microleakage and unfilled area proportion were evaluated on intact and prepared sound molar fissures. Microhardness, contact angle and acid resistance tests were performed on ground sound smooth surfaces. The samples were treated with ozone for 40 seconds (HealOzone). Control samples were treated with air (modified HealOzone) or left untreated. RESULTS: No statistically significant difference was observed between the control and ozone treated samples in all tests. Prepared fissures exhibited no unfilled areas and a statistically significantly lower microleakage compared to intact fissures. Ozone was shown to dehydrate enamel and consequently enhance its microhardness, which was reversible

Performance of four dentine excavation methods in deciduous teeth

This in vitro study aimed to assess the speed and caries removal effectiveness of four different new and conventional dentine excavation methods. Eighty deciduous molars were assigned to four groups. Teeth were sectioned longitudinally through the lesion centre. Images of one half per tooth were captured by light microscope and confocal laser scanning microscopy (CLSM) to assess the caries extension. The halves were then reassembled and caries removed using round carbide bur (group 1), Er:YAG laser (group 2), hand excavator (group 3) and a polymer bur (group 4). The time needed for the whole excavation in each tooth was registered. After excavation, the halves were photographed by light microscope. Caries extension obtained from CLSM images were superimposed on the post-excavation images, allowing comparison between caries extension and removal. The regions where caries and preparation limits coincided, as well as the areas of over- and underpreparation, were measured. Steel bur was the fastest method, followed by the polymer bur, hand excavator and laser. Steel bur exhibited also the largest overpreparation area, followed by laser, hand excavator and polymer bur. The largest underpreparation area was found using polymer bur, followed by laser, hand excavator and steel bur. Hand excavator presented the longest coincidence line, followed by polymer and steel burs and laser. Overall, hand excavator seemed to be the most suitable method for carious dentine excavation in deciduous teeth, combining good excavation time with effective caries removal

Influence of dental materials used for sealing caries lesions on laser fluorescence measurements

The aim of this study was to determine the influence of thickness and aging on the intrinsic fluorescence of sealing materials and their ability to block fluorescence from the underlying surface as assessed using a laser fluorescence device. Cavities of 0.5 mm and 1 mm depth were drilled into acrylic boards which were placed over two surfaces with different fluorescence properties: a low-fluorescence surface, to assess the intrinsic fluorescence of the sealing materials, and a high-fluorescence surface, to assess the fluorescence-blocking ability of the sealing materials. Ten cavities of each depth were filled with different sealing materials: Adper Scotchbond Multi-Purpose, Adper Single Bond 2, FluroShield, Conseal f and UltraSeal XT Plus. Fluorescence was measured with a DIAGNOdent pen at five different time points: empty cavity, after polymerization, and 1 day, 1 week and 1 month after filling. The individual values after polymerization, as well as the area under the curve for the different periods were submitted to ANOVA and the Tukey test (p < 0.05). At 0.5 mm, Scotchbond, FluroShield and UltraSeal showed insignificant changes in intrinsic fluorescence with aging and lower fluorescence after polymerization than Single Bond and Conseal. At 1 mm, Scotchbond and FluroShield showed the lowest intrinsic fluorescence, but only Scotchbond showed no chagnes in fluorescence with aging. At both depths, Scotchbond blocked significantly less fluorescence. All sealing materials blocked more fluorescence when applied to a depth of 1 mm. At 0.5 mm, fissure sealants blocked more fluorescence than adhesives, and did not show significant changes with aging. Scotchbond had the least affect on the fluorescence from the underlying surface and would probably have the least affect on the monitoring of sealed dental caries by laser fluorescence

The influence of interdental spacing on the detection of proximal caries lesions in primary teeth

The aim of this study was to investigate the influence of interdental spacing on the performance of proximal caries detection methods in primary molars. In addition, aspects related to temporary tooth separation with orthodontic separators were evaluated. The proximal spaces between the posterior primary teeth (n = 344) of 76 children (4-12 years old) were evaluated before and after temporary separation. Stainless steel strips with different standardized thicknesses were used to measure the presence of biological spacing and the spacing obtained after temporary separation with orthodontic rubber rings. First, the presence of proximal caries lesions was assessed by visual inspection, bitewing radiographs and a pen-type laser fluorescence device (DIAGNOdent pen). Visual inspection after temporary separation with separators was the reference standard method in checking the actual presence of caries. Multilevel analyses were performed considering different outcomes: the performance of the methods in detecting caries lesions and the spacing after temporary separation. The spacing did not influence the performance of the caries detection methods. The maximum spacing obtained with temporary tooth separation was 0.80 mm (mean ± standard deviation = 0.46 ± 0.13 mm). The temporary separation was more effective in the upper arch and less effective when an initial biological interdental spacing was present. The biological interdental spacing does not influence the performance of proximal caries detection methods in primary molars, and temporary tooth separation provides spacing narrower than 1.0 mm

Dental fluorosis : exposure, prevention and management

Dental fluorosis is a developmental disturbance of dental enamel, caused by successive exposures to high concentrations of fluoride during tooth development, leading to enamel with lower mineral content and increased porosity. The severity of dental fluorosis depends on when and for how long the overexposure to fluoride occurs, the individual response, weight, degree of physical activity, nutritional factors and bone growth. The risk period for esthetic changes in permanent teeth is between 20 and 30 months of age. The recommended level for daily fluoride intake is 0.05 - 0.07 mg F/Kg/day, which is considered of great help in preventing dental caries, acting in remineralization. A daily intake above this safe level leads to an increased risk of dental fluorosis. Currently recommended procedures for diagnosis of fluorosis should discriminate between symmetrical and asymmetrical and/or discrete patterns of opaque defects. Fluorosis can be prevented by having an adequate knowledge of the fluoride sources, knowing how to manage this issue and therefore, avoid overexposure