Engineering a dysbiotic biofilm model for testing root caries interventions through microbial modulation.

BACKGROUND: This study aimed to engineer and optimise a dysbiotic biofilm model to develop in vitro root caries for investigating microbial modulation strategies. The model involved growing complex biofilms from a saliva inoculum collected from four volunteers using two strategies. In the first strategy ("pre-treatment strategy"), bovine root slabs were used, and two natural compounds were incorporated at time 0 of the 10-day biofilm experiment, which included sucrose cycles mimicking the cariogenic environment. In the second strategy ("post-treatment strategy"), mature biofilms were grown in a modified Calgary biofilm device coated with collagen and hydroxyapatite for 7 days and then were exposed to the same natural compounds. The metatranscriptome of each biofilm was then determined and analysed. Collagenase activity was examined, and the biofilms and dentine were imaged using confocal and scanning electron microscopy (SEM). Mineral loss and lesion formation were confirmed through micro-computed tomography (µ-CT). RESULTS: The pH confirmed the cariogenic condition. In the metatranscriptome, we achieved a biofilm compositional complexity, showing a great diversity of the metabolically active microbiome in both pre- and post-treatment strategies, including reads mapped to microorganisms other than bacteria, such as archaea and viruses. Carbohydrate esterases had increased expression in the post-treated biofilms and in samples without sugar cycles, while glucosyltransferases were highly expressed in the presence of sucrose cycles. Enrichment for functions related to nitrogen compound metabolism and organic cyclic component metabolism in groups without sucrose compared to the sucrose-treated group. Pre-treatment of the roots with cranberry reduced microbial viability and gelatinase (but not collagenase) activity (p < 0.05). SEM images showed the complexity of biofilms was maintained, with a thick extracellular polysaccharides layer. CONCLUSIONS: This root caries model was optimized to produce complex cariogenic biofilms and root caries-like lesions, and could be used to test microbial modulation in vitro. Pre-treatments before biofilm development and cariogenic challenges were more effective than post-treatments. The clinical significance lies in the potential to apply the findings to develop varnish products for post-professional tooth prophylaxis, aiming at implementing a strategy for dysbiosis reversal in translational research. Video Abstract.

Effect of Three Chemical Agents on Stain Removal from Dentin Caries Lesions Treated with Silver Diamine Fluoride.

INTRODUCTION: This in vitro study aimed to evaluate the effect of three different chemical agents on stain removal and mineral uptake of artificial dentin caries (ADC) lesions treated with silver diamine fluoride (SDF). METHODS: Baseline L*a*b* values were determined in polished human permanent dentin blocks, and ADC lesions were induced with an acid gel for 1 week. Samples were assigned to four groups; in three groups, half of each sample received SDF (30% SDF for 3 min), while the other half received SDF followed by a bleaching treatment protocol (garlic extract, bentonite, or 35% hydrogen peroxide). The fourth group had one SDF-treated half and one half without SDF. Color changes (ΔE) were measured by spectrometry, and transversal microradiography was used to quantify integrated mineral loss (ΔZ) 24 h after treatment (SDF or SDF + bleaching). A two-way mixed ANOVA was applied to thirty percent. RESULTS: SDF application increased mineral uptake by ADC (p = 0.001). The type of chemical agent evaluated (p < 0.0001), time (p = 0.01), and their interaction (p < 0.0001) bleached the ADC treated with SDF. However, 35% hydrogen peroxide was the only compound with a bleaching effect (p < 0.001), without returning to baseline color. None of the compounds altered the mineral uptake effect of SDF (p = 0.30). CONCLUSION: This in vitro study showed mineral uptake effect in ACD within 24 h after SDF application and the ability of hydrogen peroxide to partially remove (reduction of 24%) the staining caused by SDF without affecting its mineral uptake effect.

Association of Root Biofilm Bacteriome with Root Caries Lesion Severity and Activity.

INTRODUCTION: This research aimed to assess the association of root biofilm bacteriome with root caries lesion severity and activity in institutionalised Colombian elderlies and was conducted to gather data on the root caries bacteriome in this population. METHODS: A bacteriome evaluation of biofilm samples from sound and carious root surfaces was performed. Root caries was categorised (ICDAS Root criteria) based on severity (sound surfaces, initial: non-cavitated, moderate/extensive combined: cavitated) and activity status (active and inactive). DNA was extracted and the V4 region of the 16S rRNA gene was sequenced; afterwards the classification of features was conducted employing amplicon sequence variants and taxonomic assignment via the Human Oral Microbiome Database (HOMD). Bacterial richness, diversity (Simpson's and Shannon's indices), and relative abundance estimation were assessed and compared based on root caries severity and activity status (including Sound surfaces). RESULTS: A total of 130 biofilm samples were examined: sound (n = 45) and with root caries lesions (n = 85; by severity: initial: n = 41; moderate/extensive: n = 44; by activity: active: n = 60; inactive: n = 25). Species richness was significantly lower in biofilms from moderate/extensive and active groups compared to sound sites. There was a higher relative abundance of species like Lechtotricia wadei, Capnocytophaga granulosa, Cardiobacterium valvarum, Porphyromonas pasteri - in sound sites; Dialister invisus, Streptococcus mutans, Pseudoramibacter alactolyticus and Bacteroidetes (G-5) bacterium 511 - in moderate/extensive lesions, and Fusobacterium nucleatum subsp. animalis, Prevotella denticola, Lactobacillus fermentum, Saccharibacteria (TM7) (G-5)bacterium HMT 356 - in active lesions. CONCLUSION: Root caries bacteriome exhibited differences in species proportions between the compared groups. Specifically, cavitated caries lesions and active caries lesions showed higher relative abundance of acidogenic bacteria.

The action of microbial collagenases in dentinal matrix degradation in root caries and potential strategies for its management: a comprehensive state-of-the-art review

Abstract Conventional views associate microbial biofilm with demineralization in root caries (RC) onset, while research on their collagenases role in the breakdown of collagen matrix has been sporadically developed, primarily in vitro. Recent discoveries, however, reveal proteolytic bacteria enrichment, specially Porphyromonas and other periodontitis-associated bacteria in subgingivally extended lesions, suggesting a potential role in RC by the catabolism of dentin organic matrix. Moreover, genes encoding proteases and bacterial collagenases, including the U32 family collagenases, were found to be overexpressed in both coronal and root dentinal caries. Despite these advancements, to prove microbial collagenolytic proteases' definitive role in RC remains a significant challenge. A more thorough investigation is warranted to explore the potential of anti-collagenolytic agents in modulating biofilm metabolic processes or inhibiting/reducing the size of RC lesions. Prospective treatments targeting collagenases and promoting biomodification through collagen fibril cross-linking show promise for RC prevention and management. However, these studies are currently in the in vitro phase, necessitating additional research to translate findings into clinical applications. This is a comprehensive state-of-the-art review aimed to explore contributing factors to the formation of RC lesions, particularly focusing on collagen degradation in root tissues by microbial collagenases.

A prognosis and cost-effectiveness systematic review of non-invasive treatments for root caries / Revisão sistemática de prognóstico e custo-efetividade de tratamentos não invasivos para cárie radicular

Aim: to evaluate the prognosis of root cariestreatment with non-invasive methods, as well as to compare non-invasive therapies as viable alternatives for clinicians, indicating their cost-effectiveness.Literaturereview: Data collected were number of active lesions at baseline(BL) and in the last clinical assessment after follow-up(FL), and the follow-up period in months(P). The outcome was the monthly progression rate of the lesions that was calculated by (FL­BL)/P. A negative progression rate means the arrestment of the lesions. A cost-effectiveness rate was calculated. Results: From 596 titles retrieved in the search, 8 studies were included in a qualitative synthesis after assessed for eligibility. The monthly progression rate of lesions of home-based treatments (toothpastes, mouth rinses, supplemented milk intake) was an average of -0.79 (-3.68 to 2.3), while the office-based treatments (varnish, topic solutions) was 0.07 (-0.01 to 0.51), suggesting a better prognosis of the home-based treatments. The lowest monthly progression rate was -3.97 (toothpaste 5000ppm/F) while the highest was 2.31 (conventional toothpaste). The cost-effectiveness rate was better for treatments with toothpastes with 5000ppm/F (BRL21.78) when compared to mouthwashes (BRL579.47). Discussion: A better prognosis was found for toothpastes with a high fluoride concentration (5000ppm/F) compared to other therapies, as well as a better cost-effectiveness when compared to mouthwashes. Conclusion: Home-based therapiesrepresented the highest rates of good prognosis for treating root caries lesions within the available scientific evidence. Although 5000ppm/F toothpastes have a very high cost for the Brazilian market, this treatment presented the highest cost-effectiveness when compared to mouthrinses(PROSPERO:CRD42019136035).

Objetivo: avaliar o prognóstico do tratamento da cárie radicular com métodosnão invasivos, bem como comparar as terapias não invasivas como alternativas viáveis para os clínicos, indicando seu custo-efetividade. Revisão deliteratura: os dados coletados foram o número de lesões ativas no início do estudo(BL) e na última avaliação clínica após o acompanhamento(FL), e o período de acompanhamento em meses(P). O desfecho foi a taxa de progressão mensal das lesões calculada por (FL­BL)/P. Uma taxa de progressão negativa significou a inativação das lesões. Uma taxa de custo-efetividade foi calculada.Resultados: Dos 596 títulos recuperados na busca, 8 estudos foram incluídos em uma síntese qualitativa após avaliação de elegibilidade. A taxa de progressão mensal das lesões dos tratamentos caseiros (dentifrícios, enxaguatórios bucais, ingestão de leite complementado) foi em média -0,79 (-3,68 a 2,3), enquanto os tratamentos de consultório (verniz, soluções tópicas) foi de 0,07 (-0,01 a 0,51), sugerindo um melhor prognóstico dos tratamentos domiciliares. A menor taxa de progressão mensal foi de -3,97 (dentifrício 5000ppm/F), enquanto a maior foi de 2,31 (dentifrício convencional). A taxa de custo-efetividade foi melhor para tratamentos com dentifrícios com 5000ppm/F(R$21,78) quando comparados aos bochechos (R$579,47). Discussão: Foi encontrado melhor prognóstico para dentifrícios com alta concentração de flúor(5000ppm/F) em comparação com outras terapias, bem como melhor custo-efetividade quando comparados aos bochechos. Conclusão: As terapias domiciliares representaram as maiores taxas de bom prognóstico para o tratamento de lesões de cárie radicular dentro das evidências científicas disponíveis. Embora dentifrícios de 5000ppm/F tenham um custo muito alto para o mercado brasileiro, este tratamento apresentou o maior custo-efetividade quando comparado aos enxaguatórios bucais(PROSPERO:CRD42019136035).

Prevalence, and Risk Indicators of Coronal and Root Caries in Mexican Older Adults in Nursing Homes.

Background: Several factors are associated with coronal and root caries in older persons. The purpose of this study was to determine the experience, prevalence, and risk indicators (socioeconomic, sociodemographic, and dental variables) of coronal and root caries in older persons residing in nursing homes in Mexico. Methods: A cross-sectional study was carried out in 227 dentate participants with natural teeth. Convenience sample, where all dentate residents were invited to participate. The dependent variables were coronal caries and root caries, which were determined through an oral clinical examination. The independent variables were sociodemographic factors, location, type of center, surfaces free of dental biofilm and calculus, surfaces with recession, retainers in contact with surfaces with recession, xerostomia, smoking, and the previous use of dental services. The binary logistic regression model was used in the analysis. Results: The mean age of the participants in this study was 77.7±8.8 years, and 69.2% were women. Moreover, 71.8% live in long-term care facilities, and 48.0% live in Mexico City. The prevalence of coronal and root caries was found to be 67.8% and 50.7%, respectively. Being male and living in Mexico City were risk indicators for coronal caries, and with a 1% increase in surfaces with no biofilm, the risk decreased by 2%. Being widowed, having government or no social security, denture retainers, and coronal caries were risk indicators for root caries, while the utilization of dental services indicated lower risk. Conclusion: Several variables that differ in nature were found to be risk indicators for coronal and root caries. Coronal caries increases the risk of root caries. Prevention should be aimed at identifying persons at higher risk, and dental care should be improved for persons living in long-term care institutions.

Presence of host and bacterial-derived collagenolytic proteases in carious dentin: a systematic review of ex vivo studies.

Introduction and aim: The presence of host collagenases in the degradation of the protein matrix at later stages of carious dentin lesions development, as well as the potential involvement of bacterial collagenases, have been suggested but lack conclusive evidence. This study aims to conduct a systematic review to comprehensively assess the profile of host and bacterial-derived collagenolytic proteases in both root and coronal dentin carious lesions. Methods: The search was performed in eight databases and the grey literature. Studies evaluating ex vivo dentin, extracted teeth, or biofilms from natural caries lesions were included. The methodological quality of studies was assessed using the Joanna Briggs Institute tool. Synthesis of the results and the certainty of evidence were performed following the Synthesis without Meta-analysis (SWiM) checklist and GRADE approach for narrative synthesis, respectively. Results: From 935 recovered articles, 18 were included. Although the evidence was very uncertain, it was possible to suggest that 1) MMP-2, MMP-9, MMP-13, and CT-B may be increased in carious dentin when compared to sound dentin; 2) there is no difference in MMP-2 presence, while MMP-13 may be increased in root when compared to coronal carious dentin; 3) there is no difference of MMP-2 and MMP-9 expression/activity before and after cavity sealing; 4) MMP-8 may be increased in the dentin before cavity sealing compared to dentin after cavity sealing; 5) there is no difference of MMP-20 in irradiated vs. non-irradiated carious dentin. MMP-20 probably reduces in carious outer dentin when compared to carious inner dentin (moderate certainty). Genes encoding bacterial collagenolytic proteases and protein-degrading bacteria were detected in coronal and root carious lesions. Conclusion: Trends in the direction of the effect were observed for some collagenolytic proteases in carious dentin, which may represent a potential target for the development of new treatments. (Protocol register-PROSPERO: CRD42020213141).

¿Cómo Intervenir el Proceso de Caries en Personas Mayores? Adaptación del Consenso de ORCA/EFCD/DGZ / How to Intervene the Caries Process in Older Persons? Adaptation of the ORCA/EFCD/DGZ Consensus

Los cambios demográficos y epidemiológicos actuales determinarán un aumento en la prevalencia e incidencia de caries, específicamente lesiones de caries radicular (RCLs, por sus siglas en inglés) en personas mayores, por lo que la necesidad de tratamiento de mayor cobertura y efectividad será también cada vez mayor. Este artículo resume en español la evidencia actual disponible acerca de las recomendaciones clínicas para las intervenciones preventivas, no invasivas, micro o mínimamente invasivas e invasivas para el manejo de la caries dental en personas mayores, con especial énfasis en RCLs. La presente publicación se basa en un taller de consenso, seguido de un proceso de consenso e-Delphi, realizado por un panel de expertos nominados por la Organización Europea para la Investigación en Caries (ORCA), la Federación Europea de Odontología Conservadora (EFCD) y la Federación Alemana de Odontología Conservadora (DGZ). El propósito de este artículo es presentar las principales conclusiones alcanzadas en el consenso de ORCA/EFCD/DGZ para permitir una mejor difusión del conocimiento y la aplicación de estos conceptos en la práctica clínica, orientando la correcta toma de decisiones en el manejo de la enfermedad y RCLs en las personas mayores.

Current demographic and epidemiological changes will condition increased caries prevalence and incidence, specifically root caries lesions (RCLs) in the elderly. There will be a need, therefore, for therapeutic approaches with greater coverage and effectiveness. This article summarizes, in Spanish, the current available evidence leading to clinical recommendations for preventive, non-invasive, micro or minimally invasive and invasive interventions for the management of dental caries in older people, with special emphasis on RCLs. This publication is based on a consensus workshop, followed by an e-Delphi consensus process, conducted by a panel of experts nominated by the European Organization for Caries Research (ORCA), the European Federation of Conservative Dentistry (EFCD) and the German Federation of Conservative Dentistry (DGZ). The purpose of this article is to present the main conclusions reached in the ORCA/EFCD/DGZ consensus to allow a better dissemination of knowledge and the application of these concepts in clinical practice, guiding the correct decision-making for the disease management and the RCLs in the elderly.

Classification of a patient's caries activity based on lesion activity assessment among adults: findings from a prospective cohort study.

OBJECTIVE: To investigate whether the classification of a patient's caries activity based on lesion activity assessment can predict the increment and progression of coronal and root caries lesions among adults. METHODS: This population-based prospective cohort study followed 413 individuals (mean age 54.1) from southern Brazil for 4 years. Data collection included a questionnaire and clinical examination to record coronal/root caries and gingival recession. The main outcomes were caries increment measured as decayed, missing and filled tooth surfaces (DMFS) and caries progression (surface-level analysis). The main predictor variable was patients' caries activity at baseline ("caries-inactive" or "caries-active"). Negative binomial regression models (unadjusted and adjusted) were used. RESULTS: Caries-active individuals were more likely to present DMFS increment than caries-inactive ones when migrations among DMFS components were considered (IRR [incidence risk ratio] = 1.26, 95%CI [confidence interval] = 1.01-1.58). On the other hand, no such association was found when these migrations were disregarded. The risk for coronal caries progression on filled surfaces was 90% higher among caries-active patients (IRR=1.9; 95%CI=1.4-2.6). In addition, patient's caries activity was able to predict higher risk for root caries progression in newly exposed root surfaces (IRR=1.9; 95%CI=1.0-3.6). CONCLUSION: The classification of a patient's caries activity based on lesion activity was able to foresee lesion progression on the coronal and root surfaces more susceptible to caries among adults. Clinical relevance Classifying a patient's caries activity is a useful tool for the clinical management of dental caries in adults.

Terapias no Invasivas en base a fluoruros de alta concentración para lesiones de caries radicular / Non-invasive therapies based on high fluoride concentration for root caries lesions

La mayor expectativa de vida de la población mundial ha llevado a una mayor conservación dentaria y como consecuencia, a una mayor prevalencia de caries radicular en la población mayor. La información epidemiológica ha mostrado que el enfoque invasivo de la odontología restauradora no ha sido capaz de dar una solución a esta problemática de salud pública. El enfoque de la Minimal Intervention Dentistry (MID), a través de las terapias no invasivas (TNIs) en base a fluoruros de alta concentración, podrían ser la clave para abordar esta problemática debido a su enfoque conservador, centrado en el paciente y a través del curso de vida. Este artículo pretende mostrar la evidencia existente acerca de las TNIs en base a fluoruros de alta concentración más utilizadas para lesiones de caries radicular (RCLs), a saber, los dentífricos de 5.000 ppm, barnices de flúor y fluoruro diamino de plata. La evidencia científica demuestra que estas TNIs son una alternativa terapéutica en población mayor a pesar de la aun limitada evidencia científica existente para este grupo etario. Por lo tanto, se requieren mayores estudios en población mayor que sustenten estas intervenciones clínicas, principalmente en aquella población con compromiso funcional y/o cognitivo.

The longer life expectancy of the world population has led to a greater dental conservation and, as a consequence, to a higher prevalence of root caries in the elderly population. Epidemiological data have shown that the invasive approach of restorative dentistry has not been able to provide a solution to this public health problem. The Minimal Intervention Dentistry (MID) approach, through non-invasive therapies (NIT) based on high-concentration fluorides, could be the key to address this problem due to its conservative, patient-centered and life-course approach. This article aims to show the existing evidence about the most commonly used high-concentration fluoride-based NITTs for root caries lesions (RCLs), namely 5,000 ppm dentifrices, fluoride varnishes and silver diamine fluoride. The scientific evidence shows that these NITs are a therapeutic alternative in the elderly population despite the still limited scientific evidence for this age group. Therefore, further studies are required in the elderly population to support these clinical interventions, mainly in the population with functional and/or cognitive compromise.

Laser irradiation prevents root caries: Microhardness and scanning electron microscopy analysis.

Context: A promising option for the prevention of dental caries is the use of laser irradiation. Aims: Evaluate the effects of Er:YAG, Nd:YAG, and CO2 laser irradiation, associated or not to 2% sodium fluoride (2% NaF), on root caries prevention. Material and Methods: One hundred and four human root dentin samples were divided in eight groups (n = 13). A 9-mm2-area on each dentin sample was delimited and treated as follows: G1: no treatment (control); G2: 2% NaF; G3: Er:YAG; G4: 2% NaF + Er:YAG; G5: Nd:YAG; G6: 2% NaF + Nd:YAG; G7: CO2; G8: 2% NaF + CO2. When used, the 2% NaF was applied before irradiation for 4 min. The samples were subjected to a 2-week cariogenic challenge, consisted of daily immersion in de-remineralizing solutions for 6 h and 18 h, respectively. Knoop hardness (KHN) were evaluated (10 g and 20 s) at different depths from the dentin surface. The samples (n = 3) were prepared for scanning electron microscopy (SEM). Microhardness data were analysed by one-way analysis of variance (ANOVA) and Fisher's test (α = 5%). Results: The Er:YAG laser group (KHN = 41.30) promoted an increase in acid resistance of the dentin (P < 0.05) when compared to all groups. There was no synergism between laser irradiation and 2% NaF application. Morphological changes were observed after irradiation with all lasers; carbonization and cracks were also observed, except when Er:YAG were used. Conclusions: Er:YAG laser irradiation can safely increase the acid resistance of the dentin surface of the root, since it promoted a significant increase in surface hardness. The application of 2% NaF did not result in a synergistic effect.

Manejo de cárie radicular: um guia para o dentista brasileiro baseado na tradução e adaptação cultural do consenso internacional/ORCA E EFCD / Management of root caries: a guide for the Brazilian dentist based on the translation and cultural adaptation of the international consensus/ORCA and EFCD

Objetivo: A cárie radicular é um problema da Odontologia moderna, porém é notável a falta de diretrizes sobre o seu manejo. Objetivamos elaborar e adaptar um guia a partir da tradução das recomendações do consenso in-ternacional European Organization for Caries Research (ORCA) e European Federation of Conservative Dentistry (EFCD) para as tomadas de decisão clínica na intervenção do processo de cárie na pessoa idosa, com foco na cárie radicular. Materiais e métodos: O protocolo de tradução das recomendações do consenso internacional consistiu nas etapas: (1) tradução inicial, (2) síntese da tradução, (3) retradução, (4) revisão por comitê de especialistas, com adaptação cultural. A partir da tradução, foi desenvolvido um guia com diretrizes para tratamento de cárie radicular no Brasil. Resultados: Para prevenção de novas lesões é recomendada a escovação diária com dentifrício >1.500ppm/F. Dentifrícios com 5.000ppm/F ou vernizes (>20.000ppm/F) podem ser indicados para paralisar lesões radiculares ativas e para prevenção em pessoas idosas com alta suscetibilidade à cárie radicular, e o Diamino Fluoreto de Prata (>30%) para paralisar lesões ativas. Intervenções invasi-vas diretas são indicadas dependendo da situação clínica. Discussão: Nota-se uma falta de interesse em estudos primários sobre tratamentos para cárie radicular, criando assim uma lacuna em relação ao seu manejo, que reflete no nível de evidência detectado pelo consenso. Conclusão: Guias clíni-cos são importantes para reduzir a lacuna entre a pesquisa e a prática clínica. Essa tradução para o português facilitará o acesso dos dentistas bra-sileiros em relação a evidência consolidada até o momento para o manejo de cárie radicular.

Aim: Root caries are a problem in modern dentistry, but the lack of guidelines regarding their management is notable. We aim to develop and adapt a guide based on the translation of the recommendations of the international consensus as outlined by the European Organization for Caries Research (ORCA) and the European Federation of Conservative Dentistry (EFCD) for clinical decision-making in the intervention of the caries process in the elderly, with a focus on root caries. Materials and methods: The protocol for translating the recommendations of the international consensus consisted of the following steps: (1) initial translation, (2) synthesis of the translation, (3) back-translation, (4) review by an expert committee with cultural adaptation. Based on the translation, a guide was developed with guidelines for the treatment of root caries in Brazil. Results: To prevent new lesions, daily brushing with toothpaste >1,500ppm/F is recommended. Toothpaste with 5,000ppm/F or varnishes (>20,000ppm/F) may be recommended to paralyze active root lesions and for prevention in elderly people with high susceptibility to root caries, and Silver Diamine Fluoride (>30%) to paralyze active lesions. Direct invasive interventions are indicated depending on the clinical situation. Discussion: There is a lack of interest in primary studies on treatments for root caries, thus creating a gap in relation to its management, which is reflected by the level of evidence detected in the consensus. Conclusion: Clinical guidelines are important to reduce the gap between research and clinical practice. This translation into Portuguese will facilitate access by Brazilian dentists to the consolidated evidence gathered to date for the management of root caries.

Streptococcus mutans Gene Expression and Functional Profile in Root Caries: An RNA-Seq Study.

The literature is still scarce on studies describing Streptococcus mutans global gene expression under clinical conditions such as those found on complex biofilms from sound root surfaces (SRS) and carious root surfaces (RC). This study aimed to investigate the S. mutans gene expression and functional profile within the metatranscriptome of biofilms from SRS and from RC in an attempt to identify enriched functional signatures potentially associated with the healthy-to-disease transitioning process. Total RNA was extracted, and prepared libraries (SRS = 10 and RC = 9) were paired-end sequenced using the Illumina HiSeq2500. A read count assigned to each gene of the S. mutans UA159 strain was obtained. Differentially expressed genes (DEG) between SRS and RC were identified using the DESeq2 R package, and weighted gene co-expression network analysis (WGCNA) was performed to explore and identify functional modules related to SRS and RC. We found seventeen DEG between SRS and RC samples, with three overexpressed in RC and related to membrane protein, alanyl-tRNA synthetase, and GTP-binding protein, with the remaining ones overexpressed in SRS samples and related to hypothetical protein, transposon integrase, histidine kinase, putative transporter, bacteriocin immunity protein, response regulator, 6-phospho-beta-galactosidase, purine metabolism, and transcriptional regulator. Key-functional modules were identified for SRS and RC conditions based on WGCNA, being 139 hub genes found on SRS key-module and 17 genes on RC key-module. Functional analysis of S. mutans within the metatranscriptome of biofilms from sound root and from carious root revealed a similar pattern of gene expression, and only a few genes have been differentially expressed between biofilms from SRS and those from root carious lesions. However, S. mutans presented a greater functional abundance in the carious lesion samples. Some functional patterns related to sugar (starch, sucrose, fructose, mannose, and lactose) and heterofermentative metabolisms, to cell-wall biosynthesis, and to acid tolerance stress seem to be enriched on carious root surfaces, conferring ecological advantages to S. mutans. Altogether, the present data suggest that a functional signature may be associated with carious root lesions.

Caries radicular: actualización sobre una patología de creciente interés

La caries radicular es un proceso dinámico de destrucción localizada de las superficies radiculares, dependiente de biopelícula. Esta patología afecta principalmente a la población adulta mayor con superficies radiculares expuestas y altera su calidad de vida. Las vulnerabilidades y multimorbilidades, frecuentes en este grupo de edad, limitan el autocuidado oral y son criterios para considerar en la comprensión y manejo de la patología. El diagnóstico de las lesiones de caries radicular implica conocimiento de la estructura radicular sana, los factores indicadores o de riesgo, los mecanismos de desarrollo de las lesiones y los criterios para su detección y valoración. La elección correcta de opciones de manejo tanto del riesgo como de las lesiones de caries, enfocada en la preservación de la estructura, evidencia la comprensión de la caries radicular. La caries radicular plantea un desafío para la academia, los sistemas de salud, la práctica clínica dental y la población, debido a que sus indicadores están aumentando en relación con el envejecimiento poblacional y la mayor conservación de dientes naturales. El propósito de esta revisión de tema fue presentar el estado del entendimiento actual de caries radicular. Se incluyeron 81 artículos publicados entre 1971 y 2021, sobre embriogénesis de la raíz; prevalencia, etiopatogenia; características de las lesiones; diagnóstico y propuestas de manejo a nivel del riesgo individual y de las lesiones. Esta actualización es pertinente por el reto que conlleva la presencia cada vez mayor de esta patología, junto con sus consecuencias. El planteamiento de su estado del arte sugiere áreas de investigación.

Root caries is a dynamic process of localized destruction of the root surfaces, dependent on the biofilm. Its pathology mainly affects the elderly toothed population with exposed root surfaces and disrupts their quality of life. Vulnerabilities and multimorbidities, frequent in this age group, limit oral self-care and are criteria to be considered in understanding and managing the disease. The root caries lesions diagnosis implies knowledge about the healthy root structure, indicators or risk factors, caries lesions development mechanism, and the detection and assessment criteria. The correct selection of caries risk and management options preserving tooth structure shows the understanding of root caries. The root caries represents a challenge for academia, health systems, dental practice, and the population because its indicators are increasing related to aging population and greater conservation of natural teeth. This review aimed to present the state of the current understanding of root caries. Eighty-one papers published between 1971 and 2021 were included. This considered root embryogenesis; the current understanding of root caries, its prevalence and etiopathogenesis; characteristics of the lesions; diagnosis, and care proposals both at the individual risk level, and at the lesions level. This update is relevant due to the risk that the increasing presence of this pathology carries, together with its consequences. The statement of its state of the art suggests areas of research.

Impact of detection criteria on coronal and root caries estimates in adults with and without type 2 diabetes mellitus.

OBJECTIVE: To compare caries prevalence and extent in adults with or without diabetes mellitus (DM) according to different caries detection criteria (WHO, ICDAS, and Nyvad). MATERIALS AND METHODS: A cross-sectional study was carried out including 122 individuals, 44 without DM and 78 with type 2 DM. Trained and calibrated examiners performed a visual-tactile inspection to record coronal and root caries lesions (weighted kappa > 0.7). Caries prevalence and extent were calculated according to the WHO (only cavitated lesions, missing and filled surfaces), ICDAS (all non-cavitated and cavitated lesions, missing and filled surfaces), and Nyvad (only active lesions, non-cavitated and cavitated). For root caries, lesions were classified as active or inactive. RESULTS: A significantly higher overall caries experience (DMF-S) was observed among patients with DM when the WHO (RR = 1.37; 95% CI = 1.09-1.71) and the ICDAS (RR = 1.32; 95% CI = 1.07-1.62) criteria were adopted. No difference between groups was found when the Nyvad criterion was used, although a low study power was observed in this comparison. Estimates for root caries showed a higher prevalence (PR = 2.65; 95% CI = 1.05-6.70) and risk (RR = 6.02, 95% CI = 1.81-20.00) of total D-S among diabetic patients. CONCLUSIONS: DM can predispose individuals to a higher number of root caries lesions, independently of their past caries experience. Missing teeth can overestimate caries extent in individuals with DM. CLINICAL RELEVANCE: Individuals with DM should be monitored for the prevention and control of root caries. It is recommended to splitting missing teeth from the caries estimates in studies involving adults, particularly diabetic ones.

Effect of fluoride, chlorhexidine or Nd:YAG on the progression of root dentin demineralization after removal of the demineralized organic matrix

Abstract Quantification of collagen degradation is an important parameter to evaluate dentin caries for preventive aid. Objectives: Evaluate preventive methods against root collagen degradation by the hydroxyproline assay (HYP) and microradiography technique (MRT). Methodology: Five bovine root dentin blocks were obtained and subjected to an artificial demineralization process by acetate buffer (pH 5) to induce carious lesion formation. Samples were subjected to the following therapeutic treatments: 1) 0.12% chlorhexidine for 1 min, 2) 2% fluoride for 1 min, 3) Nd:YAG Laser (400 μm diameter optical fiber, 10 Hz frequency, 60 mJ/pulse energy, 48 J/cm2 energy density, in noncontact mode for 10 s), 4) deionized water (control) for 1 min, 5) MRT control group (without treatment and removal of collagen). Samples were exposed to degradation by a collagenase enzyme for five days. The enzyme solution was collected, by colorimetry in a spectrophotometer, from the collagen matrix for the hydroxyproline release analysis. The same samples were subjected to an additional two days of demineralization to induce the progression of mineral loss. Samples were analyzed by MRT for the visualization of their degraded areas (estimation of lesion depth and mineral loss). ANOVA was applied to compare hydroxyproline release rates. MRT data were subjected to the Kruskal-Wallis test, followed by the Dunn's test. Comparisons between the initial five-day and the subsequent two-day demineralization processes were performed by repeated t-test or Wilcoxon (p<0.05) measurements. Results: The amount of HYP released from the dentin samples failed to show significant differences among the groups (p=0.09). Fluoride and chlorhexidine were able to interact with the samples, reducing the progression of dentin caries after removal of the demineralized organic matrix. CHX was the only treatment able to show significant lower lesion depth than the negative control. Conclusion: Chlorhexidine and fluoride were effective in reducing root caries progression.

Association between root/coronal caries and individual factors in institutionalised elderly using ICDAS severity and activity.

BACKGROUND: Caries in the elderly has been associated with dependence, oral-health status and -care practices. This cross-sectional study aimed to investigate the association between root/coronal caries and individual factors among institutionalised elderly people in Bogotá, Colombia, using the International Caries Detection and Assessment System severity and activity criteria (ICDAS). METHODS: A total of 226 institutionalised elderly were clinically examined for root and coronal caries in 40 institutions. Caries risk was assessed with Cariogram, and demographics, oral health knowledge and practices, oral health-related quality of life and denture-use habits using a questionnaire. RESULTS: Participants (mean age: 80.1 ± 9.3 years; 63.7% female) presented a mean number of 10.8 ± 7.3 teeth and 19.4 ± 18.8 exposed root surfaces. Prevalence of Coronal-ICDAS caries experience (C-ICDAS DF) was of 100% and of 54.4% for C-ICDAS D; mean number of C-ICDAS DFS was 16.76 ± 27.36, with 50.9% of subjects having ≥ one active C-ICDAS DS. Prevalence of Root Caries Index was of 49.1% and of R-ICDAS DF of 46%; mean number of R-ICDAS DFS was 2.03 ± 2.78, with 40.3% of subjects having ≥ one active R-ICDAS DS. Most individuals had a systemic condition (94.2%) and required oral-hygiene assistance (58%). Logistic regression analyses showed significant associations (p < 0.05): for coronal active caries when having over six teeth (OR: 2.7), and for root caries, when having coronal caries (OR: 2.41), being a man (OR: 1.95), and having over 14 teeth (OR: 0.30). Those presenting with > eight exposed root surfaces were 4.04 more likely to have root caries and 2.4 times more likely to have active root caries. CONCLUSION: In the institutionalised elderly population in Bogotá significant associations were found, both for the presence as for the activity status of root and coronal caries, with individual clinical factors including coronal caries, exposed root surfaces and number of teeth.

Survival of atraumatic restorative treatment restorations in the elderly patients: a systematic review

Abstract: This study aimed to assess the survival of glass ionomer cement (GIC) restorations performed using the atraumatic restorative treatment (ART) in elderly patients. The systematic review protocol was registered in the PROSPERO database. The records were searched until August 2020 in eight electronic bibliographic databases, and included randomized and non-randomized clinical trials and observational studies, with no restrictions on the language or year of publication. Study selection and data extraction were performed independently by two reviewers. Data were extracted, summarized, collected for qualitative analysis, and evaluated for individual risk of bias using the Joanna Briggs Institute's Critical Appraisal Tool. The literature search retrieved 5,186 records; however, only seven studies fulfilled the eligibility criteria and were included. The studies were published between 2002 and 2019. A total of 1,239 restorations were investigated at intervals of 6, 12, 24, and 60 months of follow-up. Some studies had a low risk of bias, while others had moderate and high risk of bias. In general, GIC restorations placed using ART were considered satisfactory. The 6-month, 12-month, and 24-month survival rates ranged from 81.3% to 97.2%, 72.2% to 94%, and 63% to 87%, respectively; additionally, the survival rate for the longest follow-up period (60 months) was 85%. Given the best evidence-based information regarding caries removal, we highlight the need to provide a conservative and effective technique for use in elderly patients. ART is a promising and viable alternative that guarantees the survival of restorations in elderly patients.

Diabetes mellitus and poor glycemic control increase the occurrence of coronal and root caries: a systematic review and meta-analysis.

OBJECTIVES: To assess the occurrence of coronal and root caries in adults with diabetes mellitus (DM). MATERIALS AND METHODS: This study was performed accordingly to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. A search strategy was adapted for six databases, as well as gray literature. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tools for observational studies. Revman 5.3 was used to conduct five meta-analyses. The quality of evidence of meta-analysis was evaluated by GRADE. RESULTS: From 4047 titles retrieved, 29 studies were included in qualitative synthesis and 20 in quantitative synthesis. Findings showed a higher mean of DMFT in DM individuals compared with healthy controls (mean difference = 1.71; 95% CI 1.08-2.33; p < 0.01; I2 = 55%). Individuals with type 2 DM were three times more likely to have root caries in comparison with non-DM individuals (OR = 3.17; 95% CI 1.19-8.49; p = 0.02; I2 = 70%). Individuals with uncontrolled glycemic levels within the population with DM had higher prevalence of caries than individuals with controlled DM (OR = 3.82; 95% CI 1.12-13.07; p < 0.01; I2 = 89%; DMFT index mean difference = 2.61; 95% CI 1.14-4.08; p < 0.01; I2 = 75%). CONCLUSIONS: Diabetes mellitus may increase the occurrence of coronal and root caries in adults. Poor glycemic control turned diabetic individuals more likely to have caries. CLINICAL RELEVANCE: Dental caries can be an oral sign to indicate poor glycemic control in individuals with DM. Strategies to prevent root caries should be adopted in individuals with type 2 DM. Besides, dental and medical treatments should synergistically explore whether dietary habits are healthy for controlling both, DM and caries.

Bacterial analysis of biofilms from tooth root surfaces presenting different caries activity / Análise bacteriológica de biofilmes de superfícies dentárias radiculares apresentando diferentes estágios de atividade de cárie

This study evaluated the numbers and determined the proportion of mutans streptococci and Lactobacillus spp., which are possible relevant cariogenic organisms, in biofilms recovered from lesions at root surfaces with active caries lesions (ARC), inactive caries lesions, and sound root surfaces (SRS). Samples were cultured in MSB agar for mutans streptococci counts, Rogosa agar for Lactobacillus spp. counts, and brain-heart infusion agar for total viable anaerobic counts. After incubation, the number of colony-forming units (CFUs) was determined and compared between groups by the Mann-Whitney U test with a significance level set at 95%. The proportion of counts of mutans streptococci and Lactobacillus spp. in the total viable microorganisms was also analyzed by Chi-square test. Ninety samples (30 from each surface) from 37 patients were cultured and analyzed. The CFU was similar between mutans streptococci and Lactobacillus spp.These species were present in at least half of the samples and no difference was found in the frequency of isolation of these species. Only 6 samples showed a proportion of more than 10% of mutans streptococci; 4 of the samples were from ARC. Most (93%) SRS samples did not contain viable Lactobacillus spp. The data indicate the low counts of mutans streptococci and Lactobacillus spp. in root sur-faces, regardless of the activity of caries lesions.

O estudo analisou contagens e proporções de mutans strep-tococci e Lactobacillus spp., que podem ser microorganismos importantes em lesões de cárie radicular com diferentes atividades. Biofilmes foram coletados em três locais: ARC ­ superfície radicular com lesão ativa de cárie; IRC ­ superfícies radiculares com lesão inativa de cárie; SRS ­ superfícies de raizes hígidas. As amostras foram cultivadas em agar MSB para contagens de mutans streptococci; agar Rogosa para Lactobacillus spp., e agar BHI para contagens de microrganis-mos viáveis anaeróbicos totais. Após a incubação, o número de unidades formadoras de colônias (UFCs) foi determinado e comparado entre os grupos pelo teste de Mann-Whitney U test. O nível de significância foi estabelecido em 95%. A pro-porção de contagem de mutans streptococci e Lactobacillusspp. no total de microrganismos viáveis também foi analisado através do teste de qui-quadrado. Um total de 90 amostras de 37 pacientes foram cultivadas e analisadas: 30 amostras de ARC, 30 de IRC e 30 de SRS. Números de UFC foram seme-lhantes entre os grupos para ambos, mutans streptococci e Lactobacillus spp. Estas espécies estavam presentes em pelo menos metade de todas as amostras e nenhuma diferença foi encontrada na frequência de isolamento dessas espécies dentro dos grupos. Apenas 6 amostras apresentaram mais de 10% de mutans streptococci e 4 foram de ARC. Em relação aos Lactobacillus spp., 93% das amostras não apresentaram proporção dessas bactérias nas SRS. Mutans streptococci e Lactobacillus spp. estão presentes em baixa proporção nas superfícies radiculares, independentemente da atividade das lesões de cárie.