RESUMEN

INTRODUCTION: Visual imaging of subsurface caries lesions is of vital interest in dentistry, which can be obtained by invasive radiography technique as well as by available non-destructive imaging approaches. Thus, as a first step toward the development of a new innovative approach, Spectral-domain optical coherence tomography (SD-OCT) was applied to detect the lesion depth in comparison to the established reference technique (transverse microradiography [TMR]). METHODS: Bovine enamel specimens were demineralized for 5 days, following previous studies. For OCT, the resulting artificial lesions were scanned three-dimensionally (SD-OCT) and semi-automated measured (CarLQuant). For TMR, specimens were sectioned and the lesion depth was manually determined (Inspektor Research System). RESULTS: The range of lesion depth detected with OCT was 24.0-174.0 µm (mouth rinse study), 18.0-178.0 µm (toothpastes study) and with TMR 59.2-198.0 µm (mouth rinse study), 33.2-133.4 µm (toothpastes study). We found a strong correlation between both methods in terms of lesion depth (Spearman rankwith outlierp < 0.001, Rho = 0.75, Spearman rankwithout outlierp = 0.001, Rho = 0.79). The two methods produce similar results (Passing-Bablok regression, 1.16). As deeper is the lesion, the smallest is the difference between both methods as indicated by Bland-Altman-plots. CONCLUSION: Especially in the case of deep lesions, the values obtained by both methods are in agreement, and OCT can potentially substitute TMR to detect and assess lesion depth with the benefit of being non-destructive.

Asunto(s)

Caries Dental , Esmalte Dental , Microrradiografía , Tomografía de Coherencia Óptica , Tomografía de Coherencia Óptica/métodos , Animales , Bovinos , Caries Dental/diagnóstico por imagen , Caries Dental/patología , Microrradiografía/métodos , Esmalte Dental/diagnóstico por imagen , Esmalte Dental/patología , Imagenología Tridimensional/métodos , Desmineralización Dental/diagnóstico por imagen , Desmineralización Dental/patología

RESUMEN

INTRODUCTION: The acquired pellicle formation is the first step in dental biofilm formation. It distinguishes dental biofilms from other biofilm types. OBJECTIVE: To explore the influence of salivary pellicle formation before biofilm formation on enamel demineralization. METHODOLOGY: Saliva collection was approved by Indiana University IRB. Three donors provided wax-stimulated saliva as the microcosm bacterial inoculum source. Acquired pellicle was formed on bovine enamel samples. Two groups (0.5% and 1% sucrose-supplemented growth media) with three subgroups (surface conditioning using filtered/pasteurized saliva; filtered saliva; and deionized water (DIW)) were included (n=9/subgroup). Biofilm was then allowed to grow for 48 h using Brain Heart Infusion media supplemented with 5 g/l yeast extract, 1 mM CaCl2.2H2O, 5% vitamin K and hemin (v/v), and sucrose. Enamel samples were analyzed for Vickers surface microhardness change (VHNchange), and transverse microradiography measuring lesion depth (L) and mineral loss (∆Z). Data were analyzed using two-way ANOVA. RESULTS: The two-way interaction of sucrose concentration × surface conditioning was not significant for VHNchange (p=0.872), ∆Z (p=0.662) or L (p=0.436). Surface conditioning affected VHNchange (p=0.0079), while sucrose concentration impacted ∆Z (p<0.0001) and L (p<0.0001). Surface conditioning with filtered/pasteurized saliva resulted in the lowest VHNchange values for both sucrose concentrations. The differences between filtered/pasteurized subgroups and the two other surface conditionings were significant (filtered saliva p=0.006; DIW p=0.0075). Growing the biofilm in 1% sucrose resulted in lesions with higher ∆Z and L values when compared with 0.5% sucrose. The differences in ∆Z and L between sucrose concentration subgroups was significant, regardless of surface conditioning (both p<0.0001). CONCLUSION: Within the study limitations, surface conditioning using human saliva does not influence biofilm-mediated enamel caries lesion formation as measured by transverse microradiography, while differences were observed using surface microhardness, indicating a complex interaction between pellicle proteins and biofilm-mediated demineralization of the enamel surface.

Asunto(s)

Biopelículas/crecimiento & desarrollo , Esmalte Dental/microbiología , Saliva/química , Sacarosa/química , Desmineralización Dental/microbiología , Animales , Bovinos , Esmalte Dental/química , Película Dental/microbiología , Dureza , Microrradiografía/métodos , Pasteurización , Valores de Referencia , Saliva/microbiología , Sacarosa/análisis , Propiedades de Superficie

RESUMEN

Abstract The acquired pellicle formation is the first step in dental biofilm formation. It distinguishes dental biofilms from other biofilm types. Objective To explore the influence of salivary pellicle formation before biofilm formation on enamel demineralization. Methodology Saliva collection was approved by Indiana University IRB. Three donors provided wax-stimulated saliva as the microcosm bacterial inoculum source. Acquired pellicle was formed on bovine enamel samples. Two groups (0.5% and 1% sucrose-supplemented growth media) with three subgroups (surface conditioning using filtered/pasteurized saliva; filtered saliva; and deionized water (DIW)) were included (n=9/subgroup). Biofilm was then allowed to grow for 48 h using Brain Heart Infusion media supplemented with 5 g/l yeast extract, 1 mM CaCl2.2H2O, 5% vitamin K and hemin (v/v), and sucrose. Enamel samples were analyzed for Vickers surface microhardness change (VHNchange), and transverse microradiography measuring lesion depth (L) and mineral loss (∆Z). Data were analyzed using two-way ANOVA. Results The two-way interaction of sucrose concentration × surface conditioning was not significant for VHNchange (p=0.872), ∆Z (p=0.662) or L (p=0.436). Surface conditioning affected VHNchange (p=0.0079), while sucrose concentration impacted ∆Z (p<0.0001) and L (p<0.0001). Surface conditioning with filtered/pasteurized saliva resulted in the lowest VHNchange values for both sucrose concentrations. The differences between filtered/pasteurized subgroups and the two other surface conditionings were significant (filtered saliva p=0.006; DIW p=0.0075). Growing the biofilm in 1% sucrose resulted in lesions with higher ∆Z and L values when compared with 0.5% sucrose. The differences in ∆Z and L between sucrose concentration subgroups was significant, regardless of surface conditioning (both p<0.0001). Conclusion Within the study limitations, surface conditioning using human saliva does not influence biofilm-mediated enamel caries lesion formation as measured by transverse microradiography, while differences were observed using surface microhardness, indicating a complex interaction between pellicle proteins and biofilm-mediated demineralization of the enamel surface.

Asunto(s)

Animales , Bovinos , Saliva/química , Sacarosa/química , Desmineralización Dental/microbiología , Biopelículas/crecimiento & desarrollo , Esmalte Dental/microbiología , Valores de Referencia , Saliva/microbiología , Sacarosa/análisis , Propiedades de Superficie , Microrradiografía/métodos , Esmalte Dental/química , Película Dental/microbiología , Pasteurización , Dureza

RESUMEN

There is growing evidence that C. albicans is associated with dental caries, but its role on caries development needs to be better clarified. Label="OBJECTIVE">To evaluate at the hard tissue level the effect of C. albicans on the cariogenic potential of S. mutans biofilms focusing on the mineral profile of induced carious lesions. This study also aimed to evaluate the effect of C. albicans on the acidogenic potential of S. mutans biofilms. METHODOLOGY Dual-species (CA+SM) and single-species biofilms (CA or SM) were grown on the surface of enamel slabs in the presence of glucose/sucrose supplemented culture medium for 24, 48 and 72 hours. Demineralization was evaluated through percentage of surface microhardness change (%SMC) and transversal microradiography analysis (ILM and LD) and pH of the spent medium was recorded daily. Data were analyzed by two-way ANOVA followed by Bonferroni correction. RESULTS%SMC was statistically different among the biofilms at each time point being the highest for SM biofilms and the lowest for CA biofilms which also differed from CA+SM biofilms [SM (24 h: 47.0±7.3; 48 h: 66.3±8.3; 72 h: 75.4±3.9); CA (24 h: 7.3±3.3; 48 h: 7.1±6.4; 72 h: 6.6±3.6); CA+SM (24 h: 35.9±7.39.1; 48 h: 47.2±9.5; 72 h: 47.6±9.5)]. pH of spent medium was statistically lower for SM biofilms compared to the other biofilms at each time point and remained constant over time while pH values increased from 24 to 72 h for both CA and CA+SM biofilms [SM (24 h: 4.4±0.1; 48 h: 4.4±0.1; 72 h: 4.5±0.1); CA (24 h: 6.9±0.3; 48 h: 7.2±0.2; 72 h: 7.5±0.2); CA+MS (24 h: 4.7±0.2; 48 h: 5.1±0.1; 72 h: 6.1±0.6)]. IML and LD for SM biofilms increased over time while no difference was observed from 24 to 72 h for the other biofilms. CONCLUSIONS The present data suggest that C. albicans has low enamel demineralization potential and the presence of C. albicans can reduce both the cariogenic and acidogenic potentials of S. mutans biofilms.

Asunto(s)

Biopelículas/crecimiento & desarrollo , Candida albicans/fisiología , Esmalte Dental/microbiología , Streptococcus mutans/metabolismo , Desmineralización Dental/microbiología , Ácidos/metabolismo , Animales , Bovinos , Recuento de Colonia Microbiana , Esmalte Dental/química , Pruebas de Dureza , Concentración de Iones de Hidrógeno , Microrradiografía/métodos , Valores de Referencia , Propiedades de Superficie , Factores de Tiempo

RESUMEN

OBJECTIVES: The aim of this study was to assess the effect of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves hydroalcoholic extracts on viability and metabolism of a microcosm biofilm and on enamel demineralization prevention. METHODOLOGY: Microcosm biofilm was produced on bovine enamel using inoculum from pooled human saliva mixed with McBain saliva, under 0.2% sucrose exposure, for 14 days. The biofilm was daily-treated with the extracts for 1 min. At the end, it was analyzed with respect to viability by fluorescence, CFU counting and extracellular polysaccharides (phenol-sulphuric acid colorimetric assay) and lactic acid (enzymatic assay) production. The demineralization was measured by TMR. The data were compared using ANOVA or Kruskal-Wallis (p<0.05). RESULTS: M. urundeuva All. at 100, 10 and 0.1 µg/mL and Q. grandiflora Mart. at 100 and 0.1 µg/mL reduced biofilm viability similarly to positive control (chlorhexidine) and significantly more than the negative-vehicle control (35% ethanol). M. urundeuva at 1000, 100 and 0.1 µg/mL were able to reduce both lactobacilli and mutans streptococci CFU counting, while Q. grandiflora (1000 and 1.0 µg/mL) significantly reduced mutans streptococci CFU counting. On the other hand, the natural extracts were unable to significantly reduce extracellular polysaccharides and lactic acid productions neither the development of enamel carious lesions. CONCLUSIONS: The extracts showed antimicrobial properties on microcosm biofilm, however, they had no effect on biofilm metabolism and caries protection.

Asunto(s)

Anacardiaceae/química , Antiinfecciosos/farmacología , Biopelículas/efectos de los fármacos , Myrtales/química , Extractos Vegetales/farmacología , Desmineralización Dental/prevención & control , Animales , Cariostáticos/farmacología , Bovinos , Recuento de Colonia Microbiana , Esmalte Dental/efectos de los fármacos , Esmalte Dental/microbiología , Ácido Láctico/metabolismo , Lactobacillus/efectos de los fármacos , Masculino , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microrradiografía/métodos , Hojas de la Planta/química , Polisacáridos Bacterianos/metabolismo , Reproducibilidad de los Resultados , Saliva/química , Streptococcus mutans/efectos de los fármacos

RESUMEN

Abstract There is growing evidence that C. albicans is associated with dental caries, but its role on caries development needs to be better clarified. Objective: To evaluate at the hard tissue level the effect of C. albicans on the cariogenic potential of S. mutans biofilms focusing on the mineral profile of induced carious lesions. This study also aimed to evaluate the effect of C. albicans on the acidogenic potential of S. mutans biofilms. Methodology: Dual-species (CA+SM) and single-species biofilms (CA or SM) were grown on the surface of enamel slabs in the presence of glucose/sucrose supplemented culture medium for 24, 48 and 72 hours. Demineralization was evaluated through percentage of surface microhardness change (%SMC) and transversal microradiography analysis (ILM and LD) and pH of the spent medium was recorded daily. Data were analyzed by two-way ANOVA followed by Bonferroni correction. Results: %SMC was statistically different among the biofilms at each time point being the highest for SM biofilms and the lowest for CA biofilms which also differed from CA+SM biofilms [SM (24 h: 47.0±7.3; 48 h: 66.3±8.3; 72 h: 75.4±3.9); CA (24 h: 7.3±3.3; 48 h: 7.1±6.4; 72 h: 6.6±3.6); CA+SM (24 h: 35.9±7.39.1; 48 h: 47.2±9.5; 72 h: 47.6±9.5)]. pH of spent medium was statistically lower for SM biofilms compared to the other biofilms at each time point and remained constant over time while pH values increased from 24 to 72 h for both CA and CA+SM biofilms [SM (24 h: 4.4±0.1; 48 h: 4.4±0.1; 72 h: 4.5±0.1); CA (24 h: 6.9±0.3; 48 h: 7.2±0.2; 72 h: 7.5±0.2); CA+MS (24 h: 4.7±0.2; 48 h: 5.1±0.1; 72 h: 6.1±0.6)]. IML and LD for SM biofilms increased over time while no difference was observed from 24 to 72 h for the other biofilms. Conclusions: The present data suggest that C. albicans has low enamel demineralization potential and the presence of C. albicans can reduce both the cariogenic and acidogenic potentials of S. mutans biofilms.

Asunto(s)

Animales , Bovinos , Streptococcus mutans/metabolismo , Candida albicans/fisiología , Desmineralización Dental/microbiología , Biopelículas/crecimiento & desarrollo , Esmalte Dental/microbiología , Valores de Referencia , Propiedades de Superficie , Factores de Tiempo , Ácidos/metabolismo , Microrradiografía/métodos , Recuento de Colonia Microbiana , Esmalte Dental/química , Pruebas de Dureza , Concentración de Iones de Hidrógeno

RESUMEN

Abstract Objectives: The aim of this study was to assess the effect of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves hydroalcoholic extracts on viability and metabolism of a microcosm biofilm and on enamel demineralization prevention. Methodology: Microcosm biofilm was produced on bovine enamel using inoculum from pooled human saliva mixed with McBain saliva, under 0.2% sucrose exposure, for 14 days. The biofilm was daily-treated with the extracts for 1 min. At the end, it was analyzed with respect to viability by fluorescence, CFU counting and extracellular polysaccharides (phenol-sulphuric acid colorimetric assay) and lactic acid (enzymatic assay) production. The demineralization was measured by TMR. The data were compared using ANOVA or Kruskal-Wallis (p<0.05). Results: M. urundeuva All. at 100, 10 and 0.1 μg/mL and Q. grandiflora Mart. at 100 and 0.1 μg/mL reduced biofilm viability similarly to positive control (chlorhexidine) and significantly more than the negative-vehicle control (35% ethanol). M. urundeuva at 1000, 100 and 0.1 μg/mL were able to reduce both lactobacilli and mutans streptococci CFU counting, while Q. grandiflora (1000 and 1.0 μg/mL) significantly reduced mutans streptococci CFU counting. On the other hand, the natural extracts were unable to significantly reduce extracellular polysaccharides and lactic acid productions neither the development of enamel carious lesions. Conclusions: The extracts showed antimicrobial properties on microcosm biofilm, however, they had no effect on biofilm metabolism and caries protection.

Asunto(s)

Animales , Masculino , Bovinos , Extractos Vegetales/farmacología , Desmineralización Dental/prevención & control , Biopelículas/efectos de los fármacos , Anacardiaceae/química , Myrtales/química , Antiinfecciosos/farmacología , Polisacáridos Bacterianos/metabolismo , Saliva/química , Streptococcus mutans/efectos de los fármacos , Microrradiografía/métodos , Recuento de Colonia Microbiana , Cariostáticos/farmacología , Pruebas de Sensibilidad Microbiana , Reproducibilidad de los Resultados , Hojas de la Planta/química , Ácido Láctico/metabolismo , Esmalte Dental/efectos de los fármacos , Esmalte Dental/microbiología , Viabilidad Microbiana/efectos de los fármacos , Lactobacillus/efectos de los fármacos

RESUMEN

This study aimed to test the hypotheses that (i) a parameter related to permeability, αd (ratio of squared water volume by the nonmineral volume) is, among all major component volumes (mineral, water, and organic volumes) the best predictor of quinoline infiltration in natural enamel caries (NEC), and (ii) the pore volume fraction infiltrated by quinoline (Vqui ) in NEC is much lower than previous estimates that neglected water and organic enamel volumes. Mineral and nonmineral volumes and αd were measured at 341 histological points (from 20 approximal NEC lesions), and transport of quinoline was tracked by orientation-independent polarizing microscopy. R2 values of Vqui were 0.596 (αd ), 0.033 (mineral volume), 0.474 (water volume), and 0.011 (organic volume). Vqui values were 23% (body of the lesion), 7% (dark zone), and 9% (translucent zone), lower than previous estimates (with high effect size). Transport of quinoline occurred both parallelly and perpendicularly to prism paths, and dark zones were seen where only transport parallel to prisms occurred. In conclusion, αd was the main predictor of quinoline infiltration, but it differed from the water volume with a small effect size, and the pore volume fraction with quinoline was much lower than previous estimates.

Asunto(s)

Caries Dental/diagnóstico por imagen , Esmalte Dental/diagnóstico por imagen , Microscopía de Polarización/métodos , Quinolinas/farmacocinética , Diente/diagnóstico por imagen , Humanos , Microrradiografía/métodos , Minerales/farmacocinética , Permeabilidad

RESUMEN

Detection of occlusal caries with visual examination using ICDAS correlates strongly with histology under stereomicroscopy (SM), but dentin aspects under SM are ambiguous regarding mineral content. Thus, our aim was to test two null hypotheses: SM and microradiography result in similar correlations between ICDAS and histology; SM and microradiography result in similar positive (PPV) and negative predictive values (NPV) of ICDAS cut-off 1-2 (scores 0-2 as sound) with histological threshold D3 (demineralization in the inner third of dentin). Occlusal surfaces of extracted permanent teeth (n = 115) were scored using ICDAS. Undemineralized ground sections were histologically scored using both SM without contrast solution and microradiography after immersion in Thoulet's solution 1.47 for 24 h (MRC). Correlation between ICDAS and histology differed from SM (0.782) to MRC (0.511) (p = 0.0002), with a large effect size "q" of 0.49 (95% CI: 0.638/0.338). For ICDAS cut-off 1-2 and D3, PPV from MRC (0.56) was higher than that from SM (0.28) (p< 0.00001; effect size h = 0.81), and NPV from MRC (0.72) was lower than that from SM (1,00) (p < 0.00001; effect size h = 1.58). In conclusion, SM overestimated the correlation between ICDAS and lesion depth, and underestimated the number of occlusal surfaces with ICDAS cut-off 1-2 and deep dentin demineralization.

Asunto(s)

Microrradiografía/métodos , Microscopía/métodos , Medios de Contraste , Humanos , Reproducibilidad de los Resultados

RESUMEN

A aplicação de flúor tópico é a principal estratégia de natureza química para a remineralização de lesões incipientes (LI) clinicamente visíveis como manchas brancas (MB) por cárie. Abordagens para aumentar a retenção de F no substrato pode favorecer sua ação e para isso, tratamentos prévios da superfície do esmalte podem ser usados. O objetivo deste trabalho foi comparar a capacidade de remineralização do flúor sem e com pré-tratamento do esmalte com ácido fosfórico e nitrato de alumínio e a sua resistência após novo desafio. Sessenta espécimes de esmalte bovino foram preparados (6mm x 4mm) e selecionados por meio de análise de microdureza de superfície (MS). LI foram produzidas através de ciclagem Desmineralização-Remineralização (DES-RE) e os espécimes divididos aleatoriamente em cinco grupos, de acordo com o tratamento (n=12): V- controle (verniz de fluoreto de sódio 5% por 4 horas), F (sem pré-tratamento); P-F(condicionamento ácido com ácido fosfórico por 30s); Al-F (nitrato de alumínio a 0,05M por 1min); P-Al-F (condicionamento com ácido fosfórico a 37% + nitrato de alumínio a 0,05M). Os tratamentos foram repetidos semanalmente durante quatro semanas. Após o tratamento, os espécimes foram submetidos à nova ciclagem ácida. Após cada etapa, nova MS foi realizada e ao final das análises, um corte transversal dos espécimes foi realizado. Uma das metades foi submetida à análise da microdureza longitudinal (ML) e a outra preparada para realização da microrradiografia transversal (TMR) para a análise de conteúdo mineral perdido. O percentual de perda de dureza de superfície (%PDS) foi analisado por ANOVA a 2 critérios de medidas repetidas e Tukey e o percentual de perda de dureza longitudinal (%PDL) por ANOVA a 3 critérios de medidas repetidas e Tukey (p<0,05). Os dados de TMR no parâmetro LD (profundidade da lesão) foram analisados por ANOVA a dois critérios (p<0,05). Os resultados mostraram que a ciclagem DES-RE resultou em significante %PDS e %PDL em todos os grupos. Grupo F revelou menor perda de MS após tratamento e, F, Al-F e P-Al-F, mostraram menor perda de dureza final, após o novo desafio ácido. Na análise de %PDL, o grupo V apresentou menor perda de dureza final quando comparado com os demais grupos, nas diferentes profundidades. A análise do conteúdo mineral não revelou nenhuma diferença entre os tratamentos e fases. Nenhum dos pré tratamentos propostos foram capazes de otimizar a atuação do gel APF na remineralização de MB.(AU)

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The topical fluoride is the main chemical strategy to remineralize incipient caries lesions (ICL) visible as carious white spot lesions (WSL). Approaches to increase the fluoride retention may favor its action and therefore, enamel pretreatments can be used for this purpose. The aim of this study was to compare the potential of fluoride remineralization with and without previous enamel pretreatment with aluminum nitrate and phosphoric acid as well as their resistance after a new acid challenge. Sixty bovine enamel specimens were prepared (6mm x 4mm) and selected by the surface hardness (SH) analysis. The ICL were produced using DE-RE cycling and the specimens were randomized in five groups, according to the treatment (n=12): Vcontrol (5% sodium fluoride varnish during 4h), and four groups previously preatreated with topical application of acidulated phosphate fluoride (APF) during 4min: F (without pretreatment), P-F (phosphoric acid etching during 30s), Al-F (0.05M aluminum nitrate during 1min); P-Al-F (phosphoric acid etching + aluminum nitrate). The treatments were performed weekly during four weeks. After the treatment, the specimens were submitted to the new acid challenge. After each step, a new SH analysis was performed followed by the transversal cut of the specimens. A half was submitted to the longitudinal cross-sectional hardness analysis (LH) and the other half was prepared to transverse microradiography assessments (TMR) to determine the loss of mineral content. The percentage of surface mineral loss (%SH) was analyzed using two-way repeated-measures ANOVA and the percentage of crosssectional mineral loss (%LH) by the three-way repeated-measures ANOVA and Tukey (p<0.05). Data of TMR analysis by LD (lesion depth) parameter was analyzed with two-way ANOVA (p<0.05). The results showed significant %SH and %LH after DE-RE cycling for all groups. F group showed the lowest %SH after treatment, with no significant difference to Al-F and P-Al-F after the new acid challenge. V group showed the lowest %LH compared to the other groups, in the different depths, suggesting more resistance. Mineral content assessment did not reveal any difference among treatments and phases. None pretreatments were able to increase the potential of fluoride remineralization.(AU)

Asunto(s)

Animales , Bovinos , Grabado Ácido Dental/métodos , Cariostáticos/química , Caries Dental/terapia , Fluoruros/química , Remineralización Dental/métodos , Compuestos de Aluminio/química , Esmalte Dental/efectos de los fármacos , Pruebas de Dureza , Microrradiografía/métodos , Nitratos/química , Ácidos Fosfóricos/química , Reproducibilidad de los Resultados , Propiedades de Superficie , Factores de Tiempo , Resultado del Tratamiento

RESUMEN

Este estudo avaliou o potencial de uma pasta experimental contendo nano- HAP/fluoreto sobre a redução da desmineralização e o aumento da remineralização dentária in situ. Treze indivíduos participaram de 4 fases cruzadas e duplo cegas (14 dias cada). Quatro amostras hígidas (H) e quatro pré-desmineralizadas (MB) foram utilizadas intraoralmente por fase correspondente aos seguintes tratamentos: Nanop Plus (10% de hidroxiapatita + 900 ppm F), MI Paste Plus (CPP-ACP + 900 ppm F) , F (900 ppm F) e placebo (sem ingrediente ativos). Para isso, 480 amostras (240 de esmalte e 240 de dentina) foram selecionadas com base nos valores de microdureza de superfície, sendo a metade submetida à desmineralização (MB, solução desmineralizante com pH 5, durante 6 dias e 7 dias, respectivamente) e a outra metade permaneceu hígida (H). As amostras H foram protegidas por tela plástica para o acúmulo de biofilme; enquanto sobre as amostras MB, biofilme não foi acumulado para possibilitar a remineralização. As amostras H foram posteriormente expostas a um desafio cariogênico (20% de sacarose, 8x5min/dia para esmalte e 4x5min/dia para dentina). Os tratamentos foram feitos 2x4 min/dia, extra-oralmente. A des-remineralização foi quantificada por microradiografia transversal. Os dados foram analisados estatisticamente por ANOVA de medida repetidas seguida pelo teste de Tukey (p <0,05). Em relação à desmineralização de dentina, a Nanop Plus apresentou o melhor efeito sobre a redução da ΔZ (% minxµm), enquanto que todos os tratamentos foram capazes de reduzir similarmente a profundidade da lesão (µm) em comparação ao placebo: Nanop Plus (780,5 ± 212,0; 98,8 ± 26,2); MI Paste Plus (876,0 ± 268,4; 95,7 ± 30,5); F (900,5 ± 236,3; 96,0 ± 26,1); Placebo (1188,2 ± 502,5; 142,7 ± 28,0), respectivamente (p<0,05). Para a desmineralização do esmalte, nenhum tratamento foi capaz de reduzir o ΔZ e a profundidade da lesão em comparação ao placebo: Nanop Plus (1.000,9 ± 249,5; 45,0 ± 15,3); MI Paste Plus (883,6 ± 431,7; 60,7 ± 26,4); F (985,5 ± 313,4; 53,4 ± 21,1); Placebo (1369,6 ± 988,3; 57,2 ± 30,6), respectivamente. No que diz respeito à remineralização da dentina, todos os tratamentos foram igualmente capazes de aumentar o ganho mineral (ΔΔZ) em comparação ao placebo: Nanop Plus (910,1 ± 328,8); MI Paste Plus (964,2 ± 446,4); F (902,1 ± 606,8); Placebo (337,9 ± 408,2) (p<0,05). No esmalte, entretanto, apenas os tratamentos com Nanop Plus e F foram eficazes no aumento do ganho mineral (ΔΔZ) em comparação ao placebo: Nanop Plus (549,9 ± 405,4); MI Paste Plus (370,8 ± 230,6); F (555,5 ± 264,1); Placebo (200,4 ± 186,8) (p<0,05). A Nanop Plus é mais eficiente que a MI Paste Plus na redução da desmineralização na dentina e no aumento da remineralização do esmalte. Nenhum tratamento foi capaz de reduzir a desmineralização no esmalte, enquanto todos os tratamentos aumentaram a remineralização da dentina.

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This study evaluated the potential of an experimental paste containing nano- HA/fluoride on the reduction of dental demineralization and on the increase of dental remineralization in situ. Thirteen subjects took part in this crossover and double-blind study performed in 4 phases (14 days each). Four sound (S) and 4 predemineralized (WS) specimens were worn intraorally at each phase corresponded to the following treatments: Nanop plus (10% hydroxyapatite + 900 ppm F), MI Paste Plus (CPP-ACP + 900 ppm F), F (900 ppm F) and placebo (without active ingredients). For that, 480 specimens (240 enamel and 240 dentin) were selected by using surface microhardness; half of the samples were subjected to demineralization (WS, demineralizing solution at pH 5, for 6 and 7 days, respectively) and the other half remained sound (S). S specimens were protected from disturbance by using plastic mesh to allow biofilm accumulation; while on WS no biofilm accumulation was allowed to facilitate remineralization. S specimens were further exposed to severe cariogenic challenge (20% sucrose, 8x5min/day for enamel and 4x5min/day for dentin). The treatments were done 2x4 min/day, extraorally. The de-remineralization was quantified by transversal microradiography. The data were statistically analyzed using Repeated-Measures ANOVA followed by Tukey's test (p<0.05). In respect to dentin demineralization, Nanop Plus had the best effect on the reduction of ΔZ (%minxµm), while all treatments were similarly able to reduce to the lesion depth (µm) compared with placebo: Nanop Plus (780.5 ± 212.0, 98.8 ± 26.2); MI Paste Plus (876.0 ± 268.4; 95.7 ± 30.5); F (900.5 ± 236.3; 96.0 ± 26.1); Placebo (1188.2 ± 502.5; 142.7 ± 28.0), respectively (p<0.05). For enamel demineralization, no treatment was able to reduce ΔZ and lesion depth compared to placebo: Nanop Plus (1000.9 ± 249.5, 45.0 ± 15.3); MI Paste Plus (883.6 ± 431.7; 60.7 ± 26.4); F (985.5 ± 313.4, 53.4 ± 21.1); Placebo (1369.6 ± 988.3, 57.2 ± 30.6), respectively. In respect to dentin remineralization, all treatments were similarly able to improve mineral uptake (ΔΔZ) compared to placebo: Nanop Plus (910.1 ± 328.8); MI Paste Plus (964.2 ± 446.4); F (902.1 ± 606.8); Placebo (337.9 ± 408.2) (p<0.05). For enamel, only the Nanop Plus and F were effective in increasing mineral uptake (ΔΔZ) compared to placebo: Nanop Plus (549.9 ± 405.4); MI Paste Plus (370.8 ± 230.6); F (555.5 ± 264.1); Placebo (200.4 ± 186.8) (p<0.05). Nanop Plus is more effective than MI Paste Plus on the reduction of dentin demineralization and the increase of enamel remineralization. No treatments were able to reduce enamel demineralization, while for dentin remineralization all treatments were effective.

Asunto(s)

Humanos , Masculino , Femenino , Adulto , Cariostáticos/uso terapéutico , Durapatita/uso terapéutico , Fluoruros/uso terapéutico , Nanopartículas/uso terapéutico , Desmineralización Dental/prevención & control , Remineralización Dental/métodos , Análisis de Varianza , Método Doble Ciego , Microrradiografía/métodos , Reproducibilidad de los Resultados , Propiedades de Superficie , Resultado del Tratamiento

RESUMEN

UNLABELLED: The aim of this in vitro study was to assess the agreement among four techniques used as gold standard for the validation of methods for occlusal caries detection. Sixty-five human permanent molars were selected and one site in each occlusal surface was chosen as the test site. The teeth were cut and prepared according to each technique: stereomicroscopy without coloring (1), dye enhancement with rhodamine B (2) and fuchsine/acetic light green (3), and semi-quantitative microradiography (4). Digital photographs from each prepared tooth were assessed by three examiners for caries extension. Weighted kappa, as well as Friedman's test with multiple comparisons, was performed to compare all techniques and verify statistical significant differences. RESULTS: kappa values varied from 0.62 to 0.78, the latter being found by both dye enhancement methods. Friedman's test showed statistical significant difference (P < 0.001) and multiple comparison identified these differences among all techniques, except between both dye enhancement methods (rhodamine B and fuchsine/acetic light green). Cross-tabulation showed that the stereomicroscopy overscored the lesions. Both dye enhancement methods showed a good agreement, while stereomicroscopy overscored the lesions. Furthermore, the outcome of caries diagnostic tests may be influenced by the validation method applied. Dye enhancement methods seem to be reliable as gold standard methods.

Asunto(s)

Caries Dental/diagnóstico , Caries Dental/patología , Humanos , Microrradiografía/métodos , Microscopía/métodos , Diente Molar/patología , Coloración y Etiquetado/métodos