Enamel subsurface caries-like lesions induced in human teeth by different solutions : a TMR analysis

This study assessed the effectiveness of models for developing subsurface caries lesions in vitro and verified mineral changes by transverse microradiography (TMR). Enamel blocks from permanent (n=5) and deciduous teeth (n=5) were submitted to lesion induction by immersion in demineralizing solutions during 96 h, followed by pH cycles of demineralization (de) and remineralization (re) for 10 days. Two de-/re solutions were tested. Demineralizing solution “A” was composed by 2.2 mM CaCl2, 2.2 mM KH2PO4, 0.05 M acetic acid, with pH 4.4 adjusted by 1 M KOH. Demineralizing solution “B” was composed by 2.2 mM CaCl2, 2.2 mM NaH2PO4, 0.05 M acetic acid and 0.25 ppmF, with pH 4.5 adjusted by 1M KOH. Solution “A” produced cavitated lesions in permanent teeth, whereas solution “B” led to subsurface lesions in deciduous teeth. Solution “B” was then tested in enamel blocks from permanent teeth (n=5) and subsurface lesions were obtained, so that solution “B” was employed for both substrates, and the blocks were treated with slurries of a fluoride dentifrice (1450 ppm F, as NaF, n=5) or a fluoride-free dentifrice (n=5). Solution “B” produced subsurface lesions in permanent and primary teeth of an average (±SD) depth of 88.4μm (±14.3) and 89.3μm (±15.8), respectively. TMR analysis demonstrated that lesions treated with fluoride-free dentifrice had significantly greater mineral loss. This study concluded that solution “B” developed subsurface lesions after pH cycling, and that mineral changes were successfully assessed by TMR.Este estudo avaliou a efetividade de modelos para o desenvolvimento de lesões de cárie subsuperficiais in vitro e verificou alterações minerais por microradiografia transversal (TMR). Blocos de esmalte de dentes permanentes (n = 5) e decíduos (n = 5) foram submetidos à indução de lesão por imersão em soluções desmineralizadoras durante 96h, seguido de ciclos de pH de desmineralização e remineralização por 10 dias. Duas soluções des-/re foram testadas. A solução desmineralizadora “A” foi composta por 2,2 mM de CaCl2, 2,2 mM de KH2PO4, 0,05 M de ácido acético, com pH de 4,4 ajustado por 1 M de KOH. A solução desmineralizadora “B” foi composta por 2,2 mM de CaCl2, 2,2 mM de NaH2PO4, 0,05 M de ácido acético e 0,25 ppmF, com pH de 4,5 ajustado por 1 M de KOH. A solução “A” produziu lesões cavitadas em dentes permanentes, enquanto a solução “B” apresentou lesões subsuperficiais em dentes decíduos. Portanto, a solução “B” foi posteriormente usada em blocos de esmalte de dentes permanentes (n = 5) e lesões subsuperficiais foram obtidas. Portanto, a solução “B” foi empregada para ambos os substratos, sendo metade deles tratada com dentifrício fluoretado e a outra metade com dentifrício livre de flúor. A solução “B” produziu lesões subsuperficiais de cárie com profundidade de 88.4μm (14.3) em dentes permanentes e com 89.3 μm (15.8) em dentes decíduos e TMR demonstrou que lesões tratadas com dentifrício sem flúor tiveram maior perda mineral. Este estudo concluiu que a solução “B” desenvolveu lesões subsuperficiais após o ciclo de pH e as alterações minerais foram avaliadas com sucesso por TMR

Non-invasive and micro-invasive treatments to arrest active occlusal carious lesions in erupting permanent molars : a randomized clinical trial

This study aimed to evaluate the efficacy of non-invasive and micro-invasive treatments on the arrest of occlusal enamel carious lesions in erupting permanent molars. This two-arm randomized clinical trial included 27 subjects, aged 5–11 years, with 64 erupting permanent molars presenting active occlusal enamel carious lesions (as assessed by the International Caries Detection and Assessment System [ICDAS]; scores 1–3). The sample was randomly assigned into two treatment groups: 1) resin-modified glass ionomer cement sealant (Clinpro XT Varnish; 3M ESPE) and 2) 4-week topical fluoride varnish application (Duraphat; Colgate). All children and parents received oral hygiene and dietary instructions. Teeth were evaluated at baseline and 3, 6, 9, and 12 months regarding the eruption stage, biofilm accumulation, as well as severity and activity of the carious lesions. The Kaplan-Meier method was used to evaluate the survival estimates for inactivation of the carious lesions for both treatment groups. Multivariate Cox regression models with shared frailty were performed to identify factors associated with the outcome (p < 0.05). After 12 months, 22% and 3% of the lesions treated with topical fluoride varnish and sealant, respectively remained active. The adjusted model demonstrated that younger children had a higher probability of active enamel carious lesions arresting (hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.22-0.78; p=0.01). However, the probability of active enamel carious lesions arresting after sealant application was 8.85 times higher compared with fluoride varnish applications (p=0.01). Sealing is a more effective approach than fluoride varnish for arresting occlusal enamel carious lesions in erupting permanent molars

Influence of isolation technique on the survival of resin-modified glass-ionomer restorations in primary molars : a 9-months randomized controlled trial

Objective: To compare the survival of occlusal and occlusal-proximal restorations performed with resinmodified glass-ionomer cement (RMGIC) in deciduous molars using rubber dam and cotton rolls isolation. Material and Methods: Ninety-two patients were included and 200 deciduous molars with cavitated occlusal or occlusoproximal dentin caries lesions were randomized into two groups: cotton rolls (n = 100) and rubber dam (n = 100) and RMGIC restorations were placed. At baseline and in the follow-up visit, presence, severity and activity of caries lesions were registered. Two independent, blinded examiners evaluated the treated teeth clinically using the USPHS criteria and radiographically after 9 months. Descriptive analysis, survival curve (log-rank test) and Cox regression were performed to assess risk factors related to failure. Results: Out of the 179 teeth (92 cotton rolls group and 87 rubber dam group) evaluated at 9-month follow-up period. No lesion progression was observed radiographically. The overall treatment success rate was 85.47% (83.47% for cotton rolls and 87.35 rubber dam group). No significant difference between isolation methods was observed in the log-rank test (p = 0.16). Cox regression showed no risk factors related to failure. Conclusion: No difference was found in the survival of occlusal and occlusalproximal restorations performed with RMGIC in deciduous molars using a rubber dam and cotton rolls isolation after a 9-month follow-up period

Influência do desafio erosivo em dentes decíduos submetidos a procedimentos restauradores com diferentes protocolos adesivos – Estudo in vitro.

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Sealing of cavitated occlusal carious lesions in the dentin of deciduous molars: a randomized controlled clinical trial

Com o advento da mínima intervenção na Odontologia, o tratamento de lesões em estágios iniciais no esmalte e/ou dentina passou a envolver condutas de paralisação do processo carioso e controle clínico, enquanto em estágios mais avançados, optava-se por procedimentos minimamente invasivos, utilizando-se condutas restauradoras conservadoras da estrutura dental, enfatizando-se o tratamento da doença cárie, por meio do controle de seus fatores etiológicos. Em dentes decíduos o uso de técnicas minimamente invasivas é considerado conveniente. O procedimento restaurador após remoção seletiva de tecido cariado (RSTC) é uma abordagem contemporânea para o tratamento de lesões de cárie em dentina, exibindo bons resultados na literatura ao longo do tempo, além de diminuir a exposição desnecessária de tecido pulpar. Atualmente, existe um aumento no interesse por técnicas mais conservadoras onde o tecido cariado pode ser mantido e a cavidade selada. Este ensaio clínico randomizado controlado teve como objetivo comparar as taxas de sobrevivência de selamento e restauração de lesões cariosas oclusais cavitadas em dentina (ICDAS 5) de molares decíduos usando cimento de ionômero de vidro modificado por resina (CIVMR GC Fuji II LC® encapsulado: GC Corporation. Tóquio, Japão) e avaliar radiograficamente a progressão da cárie. Foram incluídas 32 crianças (idade média: 6 ±1,5) e 68 molares com lesões oclusais ICDAS 5 foram alocados aleatoriamente em dois grupos: grupo selamento (n = 31), no qual CIVMR foi colocado diretamente sobre a lesão cariosa, e grupo restauração (n = 37), no qual foi realizado a restauração com o mesmo material após a remoção seletiva de tecido cariado. No início do estudo e nas sessões de acompanhamento, foi realizado exame visual-táctil de cárie (severidade e atividade). No início do estudo, a profundidade e a extensão da cavidade (mesiodistal e vestíbulo-lingual) foram medidas antes da colocação do CIVMR. Um examinador independente e cego avaliou os dentes tratados usando os critérios da USPHS após um e dois anos. Radiografias interproximais padronizadas foram realizadas para avaliações da progressão das lesões. Durante o período total de acompanhamento, não foi observada progressão radiográfica de nenhuma lesão. Após um ano, a taxa global de sucesso do tratamento foi de 70,0% (78,8% para o grupo restauração e 59,3% para o grupo selamento). Nenhuma diferença significativa entre os tratamentos foi observada no teste de log-rank (p = 0,07). A regressão multivariada de Cox mostrou que os fatores de risco associados ao insucesso foram gênero (p = 0,02) e extensão mesiodistal da cavidade (p = 0,03). Após dois anos, a taxa de sucesso do tratamento diminuiu para 76,0% para o grupo restauração e 47,8% para o grupo selamento, e a diferença significativa entre os tratamentos foi observada no teste de log-rank (p <0,001). A regressão multivariada de Cox não mostrou associação entre fatores de risco e a falha do material. Pode-se concluir que após um ano de acompanhamento, o selamento das lesões de cárie oclusais cavitadas (ICDAS 5) em dentina de molares decíduos usando CIVMR mostraram eficácia semelhante às restaurações das cavidades de até 2 mm de extensão mesiodistal. No entanto, após dois anos, o selamento apresentou taxas de sobrevivência mais baixas do que as restaurações, independentemente do tamanho das cavidades.Since the advent of minimal intervention in Dentistry, the treatment of early diagnosed lesions, in the initial stages in the enamel and / or dentin, began to involve the arrestment of the carious process and clinical control, while in more advanced stages, it was done by minimally invasive procedures, using conservative restorative procedures, emphasizing the treatment of caries disease, through the control of its etiological factors. In deciduous teeth, the use of minimally invasive techniques is considered convenient. The selective caries removal (SCR) is a contemporary approach to the treatment of caries lesions in dentin, exhibiting good results in the literature over time, in addition to reducing unnecessary pulp tissue exposure. Currently, there is an increase in interest in more conservative techniques where decayed tissue can be maintained and the cavity sealed. This randomized controlled clinical trial aimed to compare the survival rates of sealing and restoring cavitated occlusal carious lesions in dentin (ICDAS 5) of deciduous molars using resin-modified glass-ionomer cement (RMGIC, GC Fuji II LC® capsule: GC Corporation. Tokyo, Japan) and to assess radiographically caries progression. 32 children were included(mean age ± standard deviation: 6 ±1,5) and 68 molars with ICDAS 5 occlusal lesions were randomly allocated into two groups: sealing group (n= 31), in which RMGIC was placed directly over the carious lesion, and restoration group (n= 37), in which a restoration with the same material was placed after selective caries removal. At baseline and in the follow-up visits, dental caries was registered, and caries activity was assessed according to a visual-tactile criterion. At baseline, cavity depth and extent (mesiodistal and buccolingual) were measured before RMGIC placement. An independent and blinded examiner evaluated the treated teeth using the USPHS criteria at one year and two years. Standardized interproximal radiographs were taken for caries progression assessments. Over the follow-up period no lesion progression was observed radiographically. After one year the overall treatment success rate was 70.0% (78.8% for the restoration group and 59.3% for the sealing group). No significant difference between treatments was observed in the log-rank test (p=0.07). Multivariate cox regression showed that the risk factors associated to failure were gender (p=0.02) and cavity mesiodistal extent (p=0.03). After two years, the treatment success rate decreased to 76.0% for the restoration group and 47.8% for the sealing group, and significant difference between treatments was observed in the log-rank test (p<0.001). Multivariate Cox regression showed no association between risk factors and failure. It can be concluded that both sealing and restoration effectively arrested caries progression within a period of two years. Besides, after the first year of sealing cavitated occlusal carious lesions in dentin (ICDAS 5) of deciduous molars using RMGIC showed similar efficacy to restorations of cavities up to 2 mm of mesiodistal extent. However, after two years sealing showed lower survival rates than restorations independent of cavities size

O efeito cárie-preventivo de um dentifício antierosivo sem flúor contendo nanohidroxiapatita

O objetivo desse estudo foi investigar o efeito cárie-preventivo de pastas dentais contendo flúor, nanohidroxiapatita e livre de flúor desenvolvidas para prevenção de erosão. Uma vez que os ataques ácidos durante os episódios erosivos são muito mais fortes do que nos de lesões de cárie; a hipótese formulada foi que esses produtos poderiam fornecer uma proteção ainda mais elevada do que a promovida pelos produtos fluoretados desenvolvidos para prevenção de lesões de cárie. Noventa amostras de dentes bovinos foram obtidas e armazenadas em solução de timol. Após o polimento da superfície elas foram imersas em solução desmineralizadora de Buskes por 21 dias para criar lesões de cárie artificiais. A perda mineral inicial (ΔZ) e a profundidade de lesão (LD) foram determinadas através da microradiografia transversal (TMR). As amostras foram dividas de maneira randomizada em cinco grupos (n=18) e escovadas diariamente (2x/dia) usando: dentifrício não fluoretado, como controle negativo (NC), AmF (1400 ppm F) anticárie (AC); AmF/NaF (475 ppm F) + SnCl2 (800 ppm Sn), anti-erosão (AE1); NaF (1400ppm F) + KNO3, anti-erosão (AE2) e dentifrício com nanohidroxiapatita – contendo (0 ppm F) (NH). A escovação foi realizada por 14 dias, durante a ciclagem de pH, usando “slurries” das respectivas pastas e saliva artificial (tempo total de contato para cada amostra: 2 min). Após a ciclagem as amostras que apresentaram perda de superfície (maioria NC e NH) foram descartadas e para as 77 amostras remanescentes novas análises de TMR foram realizadas. As alterações na perda mineral (ΔΔZ; ΔZinicial - ΔZtratamento) e na profundidade de lesão (ΔLD; LDinicial - LDtratamento) foram calculadas e analisadas estatisticamente. Todas as pastas dentais apresentaram ΔΔZ significativamente inferior à NC (-4.557 ± 2.178% em volume × mM, p 0.05). Com relação a ΔLD, apenas AE2 apresentou valores menores do que NC (p=0.033). Entre todos os outros grupos não foi observada diferença estatisticamente significante. Enquanto ambos dentifrícios antierosivos e o dentífrico anti-cárie reduziram a perda mineral numa extensão semelhante, a pasta de dental contendo nanohidroxiapatita parece não ser adequada para a inibição da progressão de cárie in vitro.The aim of the study was to investigate the caries protective effect of fluoride and nanohydroxyapatite-containing fluoride-free toothpastes developed for erosion prevention. Since the acid challenges during erosive episodes are much stronger than in caries process, the hypothesis was that these products might show even superior caries-inhibiting effect than regular fluoride toothpaste. Ninety bovine enamel samples were obtained and stored in thymol solution. After surface polishing they were immersed in Buskes’s demineralizing solution for 21 days to create artificial caries lesions. Baseline mineral loss (ΔZ) and lesion depth (LD) were determined by transversal microradiography (TMR). The samples were then randomly divided into five groups (n=18) and brushed 2x daily using: fluoride-free toothpaste, as negative control (NC); AmF (1400 ppm F) anti-caries (AC); AmF/NaF (475 ppm F) + SnCl2 (800 ppm Sn), anti-erosion (AE1); NaF (1400ppm F) + KNO3, anti-erosion (AE2) and nanohydroxyapatite-containing (0 ppm F) (NH) toothpastes. Brushing was performed during pH-cycling for 14 days using slurries of the respective toothpastes with artificial saliva (1:3 wt/wt, total contact time for each sample: 2 min). After cycling samples presenting lesion surface loss (mainly by NC and NH) were discarded and for the remaining 77 samples new TMR analyses were performed. The changes in mineral loss (ΔΔZ; ΔZbaseline - ΔZtreatment) and in lesion depth (ΔLD; LDbaseline - LDtreatment) were calculated and statistically analysed. All toothpastes caused significantly lower ΔΔZ than NC (-4557 ± 2178 vol%×μm, p0.05). In respect to lesion depth, only AE2 showed statistically significantly lower ΔLD means than NC (p=0.033). Between all other groups no statistically significant differences were detected. While both anti-erosive and the anti-caries toothpastes reduced mineral loss to a similar extent, the nanohydroxyapatite-containing toothpaste seemed not to be suitable for inhibition of caries progression in vitro

Influência do desafio erosivo em dentes decíduos submetidos a procedimentos restauradores com diferentes protocolos adesivos – Estudo in vitro.

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