The potential of galactomannan from Caesalpinia ferrea on erosive dentin wear reduction in vitro

Abstract Gels containing juca seed galactomannan (JSG) were evaluated for their potential to prevent the progression of dentin erosive wear in an in vitro study with four experimental groups (n = 9). The treatments included distilled water (DW), 0.05% stannous fluoride (121 ppm F), and 0.5% or 1% JSG. The specimens underwent a cycle (3 times/day) consisting of immersion in 1% citric acid (5 minutes), treatment (5 minutes), and artificial saliva exposure (2 hours/overnight) for 5 days. Surface changes were assessed using mechanical profilometry (wear), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The data were analyzed using ANOVA followed by Tukey's post-test (p < 0.05). The negative control group exhibited the highest wear (6.0 µm ± 3.5), significantly differing from the group treated with 0.05% stannous fluoride gel (p = 0.007), which showed less dentin loss. The groups treated with 0.5% and 1% JSG showed results similar to the negative control (p = 0.661; p = 0.212, respectively) and the stannous fluoride group (p = 0.103; p = 0.379, respectively). In the SEM images, the specimen treated with stannous fluoride showed obliterated tubules, while the JSG gels formed crystals on the dentin surface, as confirmed by the presence of oxygen and calcium in the EDS analysis. Although the JSG gels showed similar results to the stannous fluoride, did not exhibit superior efficacy at the tested concentrations.

Resumo Géis contendo galactomanana da semente de jucá (GSJ) foram avaliados quanto ao seu potencial na prevenção da progressão do desgaste erosivo dentinário em um estudo in vitro com quatro grupos experimentais (n = 9). Os tratamentos incluíram água destilada (AD), 0,05% de fluoreto de estanho (121 ppm F) e 0,5% ou 1% de GSJ. Os espécimes passaram por um ciclo (3 vezes ao dia) que consistia em imersão em ácido cítrico 1% (5 minutos), tratamento (5 minutos) e exposição a saliva artificial (2 horas/durante a noite) por 5 dias. As alterações de superfície foram avaliadas utilizando perfilometria mecânica (desgaste), microscopia eletrônica de varredura (MEV) e espectroscopia de raios-X por dispersão de energia (EDS). Os dados foram analisados por ANOVA, seguida do pós-teste de Tukey (p < 0,05). O grupo controle negativo apresentou o maior desgaste (6,0 µm ± 3,5), diferindo significativamente do grupo tratado com gel de fluoreto de estanho a 0,05% (p = 0,007), que apresentou menor perda de dentina. Os grupos tratados com 0,5% e 1% de GSJ apresentaram resultados semelhantes ao grupo controle negativo (p = 0,661; p = 0,212, respectivamente) e ao grupo de fluoreto de estanho (p = 0,103; p = 0,379, respectivamente). Nas imagens de MEV, o espécime tratado com fluoreto de estanho mostrou túbulos obliterados, enquanto os géis GSJ formaram cristais na superfície da dentina, como confirmado pela presença de oxigênio e cálcio na análise de EDS. Embora os géis GSJ tenham apresentado resultados semelhantes ao fluoreto de estanho, eles não demonstraram eficácia superior nas concentrações testadas.

Protective effect of green tea catechins on eroded human dentin: an in vitro/in situ study

Abstract The present study sought to evaluate the protective effect of Epigallocatechin-3-gallate (EGCG) and commercial green tea (GT) on eroded dentin using in vitro and in situ experimental models. For the in vitro experiment, matrix metalloproteinases (MMPs) were extracted from demineralized human coronary dentin powder (citric acid, pH 2.3) and assessed via a colorimetric assay and electrophoresis in gelatin. The gels were exposed to buffers with: control (no treatment), 0.05% sodium fluoride (NaF), 0.12% chlorhexidine digluconate (CHX), GT infusion, and 0.1% EGCG, and their respective activity was analyzed by zymography. For the in situ experiment, 20 healthy volunteers (aged 20-32 years) participated in this single-center, blind, crossover study. The subjects wore upper removable devices containing four human dentin blocks. Erosive challenge (coke-1 min) was performed four times/day/5 days. Blocks were treated for 1 min with: control (No treatment), 0.05% NaF, 0.1% EGCG, and GT. Thereafter, the specimens were subjected to stylus profilometry and SEM. ANOVA was used to evaluate dentin roughness and wear, with a significance level of 5%. In the zymography analysis, 0.12% CHX, GT, and 0.1% EGCG were found to inhibit the action of MMPs; however, in the colorimetric assay, only green tea inhibited the activity of MMPs. There were no significant differences observed in dentin roughness or wear (p > 0.05). Herein, EGCG and GT inhibited the activity of endogenous proteases, resulting in protection against erosion-induced dentin damage; however, they could not prevent tooth tissue loss in situ.

Diagnóstico e tratamento de lesões não cariosas: a visão do cirurgião-dentista do sistema público de saúde / Diagnosis and treatment of non-carious lesions: the vision of the dentist of the public health system

Introdução: as lesões dentárias não cariosas apresentam etiologia multifatorial e, caracterizam-se por ocasionar desgastes irreversíveis na estrutura dentária, sem envolvimento de microrganismos, podendo ser diagnosticadas como erosão (de origem intrínseca ou extrínseca), abfração, atrição ou abrasão. Objetivo: analisar o conhecimento de cirurgiões-dentistas a respeito do diagnóstico e do tratamento dos diferentes tipos de lesões dentárias não cariosas. Métodos: realizou-se estudo observacional, descritivo, de natureza quantitativa, utilizando-se, como instrumento de coleta de informações, um questionário semiestruturado aplicado em cirurgiões-dentistas do município de Fortaleza-CE. Os resultados foram analisados de forma descritiva e foi utilizado o teste de Qui-Quadrado com nível de significância de 5%. Resultados: verificaram-se, entre os cirurgiões-dentistas, os seguintes percentuais de acerto referentes às lesões de abfração, abrasão, atrição, erosão de origem extrínseca, erosão de origem intrínseca e erosão de origem extrínseca associada à abrasão, respectivamente: 51,97%, 20,60%, 78,43%, 81,37%, 71,57% e 7,84%. Observou-se, também, associação estatisticamente significante positiva entre o conhecimento dos profissionais a respeito de lesões de abfração e atrição e o tempo de formado. Conclusão: embora grande parte dos profissionais tenham sido capazes de identificar um plano de tratamento adequado para os casos propostos em questão, o diagnóstico das lesões não cariosas não foi preciso, exceto quando se tratou de erosão de origem intrínseca ou extrínseca e atrição que obtiveram percentual de acertos acima de 70%.

Introduction: non-carious dental lesions present multifatorial etiology, and are characterized by irreversible wear on the tooth structure, without the involvement of microorganisms, and can be diagnosed as erosion (intrinsic or extrinsic), abfraction, attrition or abrasion. Objective: to analyze the knowledge of dental surgeons regarding the diagnosis and treatment of different types of non-carious dental lesions. Methods: a quantitative, observational, descriptive study was carried out using a semistructured questionnaire as a tool for collecting information applied to dentists in the city of Fortaleza-CE. The results were analyzed in a descriptive way and the chi-square test with significance level of 5% was used. Results: the following percentages were found for abfraction, abrasion, attrition, extrinsic erosion, intrinsic erosion, and extrinsic erosion associated with abrasion, respectively: 51.97%, 20.60%, 78.43%, 81.37%, 71.57% and 7.84%. It was also observed a statistically significant positive association between the professionals' knowledge regarding abfraction and attrition lesions and the time of formation. Conclusion: although many professionals were able to choose an adequate treatment plan for the proposed cases, the diagnosis of non-carious lesions was not precise, except for intrinsic or extrinsic erosion, and attrition that obtained a percentage of right answers above 70%.

Active compounds and derivatives of camellia sinensis responding to erosive attacks on dentin

Abstract This research explored the potential of Camellia sinensis-derived teas and active compounds to be used as treatments to prevent dentin wear. Human root dentin slabs were randomly assigned to 5 groups (n = 10) as follows: distilled water (DW, control), epigallocatechin-3-gallate (EGCG), theaflavin gallate derivatives (TF), commercial green tea (GT), and commercial black tea (BT). The samples were submitted to a pellicle formation and an erosive cycling model (5x/day, demineralization using 0.01 M hydrochloric acid/60 s) followed by remineralization (human stimulated saliva/60 min) for three days. The samples were treated for 5 min using the test group solutions between the erosive cycles. Dentin changes were assessed with profilometry analysis and FT-Raman spectroscopy. The data regarding wear were analyzed by ANOVA followed by Tukey's test (p < 0.05). EGCG, TF derivatives, and both regular teas significantly suppressed erosive dentin loss (38-47%, p < 0.05). No obvious changes in the Raman spectra were detected in the specimens; however, the DW group had a minor relationship of 2880/2940 cm−1. The phenolic contents in both green and black tea and the important catechins appear to have protective effects on dentin loss.

Effect of green tea as a protective measure against dental erosion in coronary dentine

Abstract The aim of this study was to evaluate the effect of green tea as a protective measure on eroded dentin. Disks of human coronary dentin were selected based on surface hardness and randomly assigned to 3 groups (n = 10): DW - distilled water, CHX - 0.2% chlorhexidine digluconate, and GT - green tea. The disks were allowed to acquire pellicle for 2 hours and were then subjected to 3 cycles per day of demineralization (C6H8O7 0.05 M, pH 3.75, 60 s), treatment (DW or CHX or GT, 5 min) and remineralization (artificial saliva, 60 min) over a period of 3 days. Changes in the dentin were determined by loss of surface hardness (%SHL) and mechanical profilometry analysis at the end of each day. Data were analyzed by two-way ANOVA followed by Tukey’s test for %SHL and profilometry (p < 0.05). Significant reductions in dentin hardness loss were observed only for the CHX group when compared to the DW group (p < 0.05). However, there was no significant difference between the CHX and GT groups (p > 0.05). A significant difference was observed between DW and GT treatments for wear and roughness measurements (p < 0.05). The green tea extract solution was able to reduce the wear and roughness caused by dentin erosion under the conditions of this study.

Avaliação indireta do grau de conversão de resina composta utilizando dois protocolos de fotoativação / Indirect evaluation of degree of conversion of composite resin by two protocols of photoactivation

Introdução: as resinas compostas são materiais largamente utilizados na Odontologia estética, contudo suas propriedades físicas e químicas estão diretamente relacionadasao seu Grau de Conversão (GC). O objetivo do estudo foi avaliar in vitro oGC de uma resina composta com diferentes protocolos de fotoativação. Material e Métodos - Foram confeccionados 10 espécimes de resina composta (2,5 x 5 mm²),os quais foram fotoativados por aparelho tipo LED, utilizando dois protocolos de fotoativação: Convencional (C): 1000 mW/cm² em 20 s e Exponencial (E): de 0 a1000 mW/cm² em 5 s e 1000 mW/cm² em 15s. O GC foi obtido indiretamente pelo teste de microdureza (MD), carga de 10g/10s, após 24 horas e 7 dias da fotoativação,sendo realizado 5 endentações no topo e na base de cada espécime. Resultados - Osdados foram submetidos aos testes estatísticos t não-pareado (protocolos; região demensuração) e teste t pareado (tempo de armazenamento), com α=5%. Os resultados mostraram que as superfícies de topo apresentaram maiores valores de dureza que às superfícies de base (p<0,05) para ambos os protocolos. O protocolo C apresentou maiores valores de dureza nas superfícies de base, nos dois períodos de avaliação(p<0,05), quando comparado ao protocolo E, entretanto, nas superfícies de topo, não houve diferença estatística significante entre os protocolos C e E (p>0,05). Conclusões- O protocolo convencional apresentou maior grau de conversão da resina compostaque o exponencial, quando analisada a dureza de resina composta fotoativada por LED.

Introduction: composite resins are materials widely used in esthetic dentistry; however their physical and chemical properties are directly related to their degreeof conversion (DC). The aim of this in vitro study was to evaluate the degree of conversion (DC) of a composite resin cured by different protocols. Material and Methods - Ten samples of the composite resin (2.5 x 5 mm²) were confectioned and light cured by a LED unit, using two photoactivation protocols: Standard (S): 1000mW/cm² by 20 s and Ramp (R): 0 to 1000 mW/cm² by 5 s 1000 mW/cm² by 15 s. The DC of the resin was indirectly obtained by microhardness (MH) test, load of 10 g for10s, 24 hours and 7 days after photoactivation and five indentations were made onthe top and bottom surfaces of each sample. Results - The results were submitted topaired t-test (protocols; region of measurement) and unpaired t-test (times of storage),with level of significance of 5%. The top of the specimens showed statistically higher hardness values than the bottom surfaces (p<0,05), independent of the used protocol. S protocol showed higher hardness values in the bottom surfaces, in bothperiods of evaluation (p<0,05), in comparison to R protocol, however, in the top of the specimens, no statistically significant difference between S and R protocols were observed (p>0,05). Conclusions - The Standard protocol shows a higher compositeresin’s DC than ramp, when the hardness of the composite resin light cured by a LED unit was analyzed.

Efficacy of smear layer removal by cavity cleaning solutions: an atomic force microscopy study / Eficácia da remoção da lama dentinária por soluções de limpeza cavitária: estudo de microscopia de força atômica

PURPOSE: To evaluate the efficacy of smear layer removal by cavity cleaning agents by the use of atomic force microscopy (AFM). METHODS: Five intact human third molars were sectioned in the coronal portion to obtain dentin disks, which were ground with 600-grit abrasive paper for 10 s. Serial longitudinal sections were made perpendicular to each other to create four specimens, from each tooth. The specimens were divided into four treatment groups: GI, 2 percent chlorhexidine; GII, calcium hydroxide solution; GIII, 1.23 percent fluoride solution; and GIV, 37 percent phosphoric acid. The solutions were applied with a brush for 60 s, with the exception of the 37 percent phosphoric acid, which was applied for 15 s and rinsed with distilled water for 60 s. The specimens were examined by AFM. RESULTS: All of the specimens in GI and GII showed 100 percent of the dentin tubules obliterated by the smear layer. However, all of the specimens in GIII and GIV showed 0 percent of the dentin tubules obliterated by the smear layer. CONCLUSION: The 1.23 percent fluoride solution was effective in removing the smear layer and can be used as a cavity cleanser.

OBJETIVO: Avaliar a eficácia da remoção de lama dentinária por agentes de limpeza cavitária através da análise de microscopia de força atômica (MFA). METODOLOGIA: Cinco terceiros molares humanos hígidos foram seccionados transversalmente na porção coronária, obtendo discos de dentina de 2 mm, que foram desgastados com lixas de granulação 600, por 10 s.Foram feitos cortes seriados longitudinais e perpendiculares entre si, obtendo-se quarto espécimes de cada dente. Os espécimes foram divididos em 4 grupos: GI- clorexidina a 2 por cento; GII- água de hidróxido de cálcio; GIII- solução fluoretada a 1,23 por cento; GIV - ácido fosfórico 37 por cento. As soluções foram aplicadas com pincel por 60 s, com exceção do ácido fosfórico que foi aplicado por 15 s e lavado com água destilada pelo mesmo tempo. Os espécimes foram analisados por MFA. RESULTADOS: Todos os espécimes de GI e GII apresentaram 100 por cento dos túbulos dentinários obliterados por lama dentinária. Os espécimes de GIII e GIV apresentaram 0 por cento dos túbulos obliterados por lama dentinária. CONCLUSÃO: A solução de fluoretada a 1,23 por cento foi eficiente na remoção de lama dentinária, podendo ser empregada na limpeza de cavidades.

Two-year clinical evaluation of resinous restorative systems in non-carious cervical lesions

This controlled clinical trial evaluated the 2-year clinical performance of a one-bottle etch-and-rinse adhesive and resin composite system (Excite/Tetric Ceram) compared to a resin-modified glass ionomer cement (RMGIC) (Vitremer/3M) in non-carious cervical lesions. Seventy cervical restorations (35 resin composite - RC- restorations and 35 RMGIC restorations) were placed by a single operator in 30 patients under rubber dam isolation without mechanical preparation. All restorations were evaluated blindly by 2 independent examiners using the modified USPHS criteria at baseline, and after 6, 12 and 24 months. Data were analyzed statistically by Fisher's exact and McNemar tests. After 2 years, 59 out of 70 restorations were evaluated. As much as 78.8 percent retention rate was recorded for RC restorations, while 100 percent retention was obtained for RMGIC restorations. Fisher's exact test showed significant differences (p=0.011) for retention. However, there were no significant differences for marginal integrity, marginal discoloration, anatomic form and secondary caries between the RC and RMGIC restorations. The McNemar test detected significant differences for Excite/TC between baseline and the 2-year recall for retention (p=0.02), marginal integrity (p=0.002) and anatomic form (p=0.04). Therefore, the one-bottle etch-and-rinse bonding system/resin composite showed an inferior clinical performance compared to the RMGIC.

Esse estudo avaliou o desempenho clínico de restaurações de lesões cervicais não-cariosas por um período de 2 anos empregando um sistema adesivo de condicionamento total (Excite/Tetric Ceram) e um cimento de ionômero de vidro modificado por resina (Vitremer). Setenta restaurações (35 por material) foram realizadas por um único operador. Todas as lesões cervicais não-cariosas foram restauradas sem a execução de preparo cavitário e sob isolamento absoluto. As restaurações foram avaliadas por 2 examinadores independentes usando os critérios USPHS modificados nos períodos inicial, 6, 12 e 24 meses. A análise estatística foi realizada pelos testes de Fisher e McNemar. Cinquenta e nove restaurações foram avaliadas após 2 anos, obtendo-se um índice de retenção de 78,8 por cento para resina composta e 100 por cento para o cimento de ionômero de vidro modificado por resina. O teste exato de Fischer detectou diferença significante (p=0,011) para retenção entre os dois materiais. Contudo, não houve diferença significante para integridade marginal, descoloração marginal, forma anatômica e cárie secundária. O teste de McNemar detectou diferença estatística para o sistema Excite/Tetric Ceram entre o período inicial e 2 anos para os critérios de retenção (p=0,02), integridade marginal (p=0,002) e forma anatômica (p=0,04). Portanto, o sistema adesivo de condicionamento total apresentou um desempenho clínico inferior comparado ao cimento de ionômero de vidro modificado por resina.