Rodrigo Alex Arthur

• Federal University of Rio Grande do Sul

The oral cavity presents a highly diverse microbial composition. All the three domains of life, Bacteria, Eukarya, and Archaea, as well as viruses constitute the oral microbiome. Bacteria are among the most abundant microorganisms in the oral cavity, followed by viruses, fungi, and Archaea. These microorganisms tend to live in harmony with each oth...

This article describes a new multifunctional oral cavity simulator (MOCS) that allows, with little technical support and easy handling, the laboratory development of dental hard tissue lesions under clinically similar conditions. The MOCS consists of a heating unit containing three independent cylindrical chambers with three specimen holders inside...

Objetivo: realizar uma revisão narrativa da literatura sobre os componentes orgânicos salivares e suas funções, bem como a relação entre esses componentes orgânicos com condições de saúde bucal e cárie dentária, na tentativa de identificar potenciais candidatos a marcadores biológicos de cárie dentária. Revisão de literatura: a saliva desempenha vá...

The aim was to evaluate the effect of probiotics‐containing beverages on dental caries development by a systematic review and meta‐analysis (PROSPERO CRD42021258010). PubMed, Embase, and Web of Science databases were assessed (up to October 2023) for randomized placebo‐controlled trials that evaluated the consumption of probiotics‐containing bevera...

The aim of this paper was to present a summary of the process of developing and preparing the final documents of the national consensus for teaching undergraduate Brazilian dental students the dental caries curriculum in the Portuguese language. The final document was developed in three steps: a) The ABENO and LAOHA cariology group invited experts...

Objective This study aimed to analyze the functional profile of supragingival biofilm from sound (CAs), active (CAa), and inactive (CAi) enamel caries lesions from caries-active individuals to provide insights into the diversity of biological processes regarding biofilm dysbiosis. Methodology A metatranscriptome analysis was performed in biofilm s...

Objective This study aimed to evaluate the microbial functional profile of biofilms related to caries-free (CF, n = 6) and caries-arrested (CI, n = 3) compared to caries-active (CA, n = 5) individuals. Materials and methods A metatranscriptomic was performed in supragingival biofilm from different clinical conditions related to caries or health. T...

Objective Some salivary proteins seem to be differently abundant among caries-free (CF) and caries-affected (CA) individuals, but previous results are contradictory precluding that definitive conclusion be drawn. A pooled analysis of the available evidence may provide more robust data on identifying oral cavity protein patterns among CF and CA indi...

Bacteria, fungi, archaea, protozoa, viruses, and bacteriophages colonize the oral cavity and, in combination, they form the oral microbiome. The coexistence of different microorganisms and the microbial balance at each specific site are warranted by synergistic and antagonist interactions among members of the microbial communities. This microbiolog...

Nutritional supplements have been recommended to cope with malnutrition in elderly persons. In Chile, the Supplementary Nutrition Program for the Elderly (PACAM, for its Spanish acronym) consists in a monthly distribution of a low-fat-milk-based drink that contains 8% sucrose. The aim of this study was to determine whether older persons consuming t...

Aim: Stevia rebaudiana Bertoni (Stevia) is a natural non-caloric sweetener that can modify the cariogenicity of biofilms. This study aimed to evaluate the effect of Stevia infusion in microbial and biochemical composition of biofilms formed in the presence of sucrose and on enamel demineralization. Materials and Methods: In a cross-over design, ele...

Bacteria and fungi can interact to form inter-kingdom biofilms in the oral cavity. Streptococcus mutans and Candida albicans are frequently detected in saliva and in dental biofilms associated with early childhood caries (tooth-decay), a prevalent oral disease induced by dietary sugars. However, how different sugars influence this bacterial-fungal...

Introduction: Streptococcus mutans and Candida albicans are frequently detected together in the plaque from patients with early childhood caries (ECC) and synergistically interact to form a cariogenic cross-kingdom biofilm. However, this biofilm is difficult to control. Thus, to achieve maximal efficacy within the complex biofilm microenvironment,...

The literature is still scarce on studies describing S. 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...

This comprehensive review of the literature aimed to investigate the interplay between the oral microbiome, oral cavity conditions, and host immune response in Diabetes mellitus (DM). Moreover, this review also aimed to investigate how DM related risk factors, such as advanced age, hyperglycemia, hyperlipidemia, obesity, hypertension and polycystic...

The oral microbiome is unique at inter and intra-individual levels at various sites due to physical and biological factors. This study aimed to compare the bacterial composition of supragingival biofilms collected from enamel sites with different caries activity, from active and inactive-caries subjects, and from caries-free (CF) subjects. Twenty-t...

Caries management at the lesion level is dependent on the lesion activity, the presence of a cavitation (either cleanable or non-cleanable), and lesion depth as evaluated via radiographic examination. A variety of non-invasive, micro-invasive, and minimally invasive treatment (with or without restoration) options are available for primary and perma...

There is increasing evidence showing positive association between changes in oral microbiome and the occurrence of oral squamous cell carcinoma (OSCC). Alcohol- and nicotine-related products can induce microbial changes but are still unknown if these changes are related to cancerous lesion sites. In an attempt to understand how these changes can in...

Aim: This study aimed to compare the microbiological potential and gustatory perception of essential oils (EO) mouthrinses containing and not containing alcohol. Methods: Twenty healthy adult volunteers rinsed with 10mL of the following test solutions: EO with alcohol, EO without alcohol, or a control solution (saline solution with mint essence). A...

The oral cavity is a highly diverse microbial environment in which microorganisms interact with each other, growing as biofilms on biotic and abiotic surfaces. Understanding the interaction among oral microbiota counterparts is pivotal for clarifying the pathogenesis of oral diseases. Candida spp. is one of the most abundant fungi in the oral mycob...

Objective This study aimed to evaluate the anti-caries effect of a fluoridated milk-based drink on a root caries model by assessing mineral loss and both biofilm microbial viability and acidogenicity under increasing concentrations of fluoride supplementation. Design Streptococcus mutans UA159 biofilms were grown on root dentin slabs for five days...

Objective This systematic review and meta-analysis aimed to investigate whether the presence of fungi of the genus Candida in oral cavity is associated with dental caries in children and adolescents (from 6 to 18 years) or in adults (older than 18 years). Design Electronic search was carried out in MEDLINE, EMBASE and LILACS databases. Studies tha...

Significance Dental caries remains an unresolved public health problem. The etiology is poorly understood, as the oral cavity harbors diverse communities of microorganisms. Using multiple imaging modalities on human teeth from patients with caries, we discovered a microbial community precisely arranged in a corona-like architecture. Moreover, this...

Purpose: The aim of this study was to evaluate the chemomechanical properties, antibacterial activity, and cytotoxicity of an experimental adhesive resin containing halloysite nanotubes (HNT), doped with alkyl trimethyl ammonium bromide (ATAB). Materials and methods: A filler of HNT doped with ATAB was obtained (ATAB:HNT) and incorporated (5 wt%...

Objective: This study aimed to evaluate the anti-caries effect of a fluoridated milk-based drink on a root caries model by assessing mineral loss and both biofilm microbial viability and acidogenicity under increasing concentrations of fluoride supplementation. Design: Streptococcus mutans UA159 biofilms were grown on root dentin slabs for five day...

Caries-detecting dyes were developed to guide the dentist to precisely differentiate between carious dentin and sound dentin during carious dentin removal prior to placement of a restoration. Studies have shown that during a caries removal process it is impossible to leave a cavity without bacteria even with the use of disclosing dyes. There is evi...

Oral cavity harbors a complex and highly diverse microbial community. Cross-kingdom interactions between Candida and oral bacteria are critical for their co-existence, which may also affect the course and the severity of biofilm-mediated bacterial-mediated diseases. C. albicans has been found in polymicrobial biofilms associated with denture stomat...

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...

Peracetic acid (PAA) has been used to sterilize biomaterial scaffolds and allografts before their implantation. Although the antimicrobial effectiveness of PAA is widely known, there are no studies investigating its cytotoxicity on keratinocytes. This study aimed to investigate the cytotoxicity of PAA concentrations on keratinocytes by growing HaCa...

Statement of problem: Soaking dentures in vinegar or hydrogen peroxide does not seem to remove the microorganisms involved with prosthetic stomatitis efficiently. A mixture of these 2 substances may be effective, but studies are lacking. Purpose: The purpose of this in vitro study was to evaluate the antimicrobial effect and cytotoxic activity o...

This in situ study aimed to evaluate the antibacterial and anti-demineralization effects of an experimental orthodontic adhesive containing triazine and niobium phosphate bioglass (TAT) around brackets bonded to enamel surfaces. Sixteen volunteers were selected to use intra-oral devices with six metallic brackets bonded to enamel blocks. The experi...

Maltodextrins, derived from corn starch, have been added to industrialized food combined with sucrose. However it is not clear the diffusion properties of the dental biofilm matrix and the tridimensional structure of multispecies biofilms formed in the presence of these carbohydrates. Therefore, the aim of study was to investigate by confocal laser...

The aim of this study was to evaluate the cariogenicity of a milk-based drink intended for older adults that was used as part of a governmental initiative in Chile to improve their nutritional conditions. This drink contains a high concentration of sugars, which can contribute to root caries development. To test this hypothesis, an experimental bio...

Objetivo: avaliar a atividade antimicrobiana in vitro daplanta Stevia rebaudiana Bertoni e de adoçantes nãocalóricos sobre o crescimento de Streptococcus mutanse Lactobacillus casei, micro-organismos cariogênicospresentes na cavidade bucal. Materiais e método: oestudo foi realizado utilizando as cepas padrões de S.mutans (UA159) e L. casei (ATCC746...

Objectives: Evaluate the ability of objectively measured specular reflection, roughness, and fluorescence change during dehydration to assess caries lesion activity. Methods: One hundred ninety-five ground/polished 3 × 3 x 2 mm sound human enamel specimens were divided into three groups and demineralized using a multispecies microbial caries mod...

There is limited evidence that arginine-containing fluoridated dentifrices (AFD) have a better anticaries effect than regular fluoridated dentifrices (FD), especially in subjects at a higher risk for caries development. This study aimed to assess the effect of AFD on enamel demineralization and on the microbial and biochemical compositions of biofi...

Introduction: Infiltration of carious lesion has been claimed as a promising approach for the management of non-cavitated proximal lesions (NCPL). Clinical studies have suggested that this approach may reduce NCPL progression in individuals whose caries risk was not change over the studied period. Objective: This study aimed to assess the additi...

Objective: To evaluate the immediate enamel bond strength, in situ degree of conversion and the polymerisation rate of three experimental orthodontic adhesives containing triclosan-loaded halloysite nanotubes. The antibacterial and bioactivity properties of such experimental materials were also assessed. Materials and methods: Three experimental...

Aim: To develop an endodontic sealer with amoxicillin-loaded microsphere and to evaluate its properties. Methods: Experimental sealer was obtained by mixing 70wt% UDMA, 15wt% GDMA and 15wt% BISEMA. In addition, CQ, DHEPT and PB were incorporated at 1 mol% and 0.01wt% BHT and 10wt% YbF3. Microspheres were produced by drying in spray dryer. Two ex...

Background Early childhood caries (ECC) is an aggressive condition that can affect teeth of young children. This study aimed to evaluate genotypic diversity and phenotypic traits of S. mutans isolated from dental biofilms of children with different caries status in comparison with caries free (CF) children. Methods Streptococcus mutans strains wer...

Objective: To incorporate indomethacin and triclosan-loaded nanocapsules into primer and adhesive, and evaluate its properties. Methods: Indomethacin and triclosan were encapsulated by deposition of preformed polymer and subsequently characterized regarding morphology, particle size, drug content and cytotoxicity. Nanocapsules (NCs) were incorpo...

Maltodextrin is a hydrolysate of cornstarch and has been widely used in the food industry associated with sucrose. The addition of starch can increase the cariogenic potential of sucrose; however, there are sparse data regarding the cariogenicity of sucrose associated with maltodextrin. Therefore, the aim of this study was to test in situ if maltod...

Objectives White spot lesions are still a concern for orthodontic patients. The objective of this study was to assess the remineralizing and antibacterial effect of a newly developed orthodontic adhesive. Methods The compounds 1,3,5-tryacryloylhexahydro-1,3,5-triazine (TAT) and phosphate invert glass containing 10 mol% of niobium pentoxide (PIG-Nb)...

Objetivo: avaliar a influência do número de imersões em ácido peracético na colonização bacteriana, na composição química, na rugosidade e na capacidade de recuperação após a deformação de tubos endotraqueais. Materiais e método: quatro tubos foram sub-metidos a sucessivas imersões em ácido peracético, constituindo quatro grupos: um controle (ester...

Objective: The aim of this double-blind randomized clinical trial was to assess whether the presence of alcohol in chlorhexidine gluconate mouthwashes influences their antimicrobial potential against salivary bacteria in young adults. Additionally, the taste perception was assessed. Materials and methods: In a randomized crossover design, 20 par...

Objective This study aimed to incorporate silver nanoparticle solutions (AgNP) in an orthodontic adhesive and evaluate its physicochemical and antimicrobial properties. Material and Methods Silver nanoparticle solutions were added to a commercial adhesive in different concentrations (w/w): 0%, 0.11%, 0.18%, and 0.33%. Shear bond strength (SBS) tes...

Objective: This study aimed to assess the in vitro cariogenic potential of some Bifidobacterium species in comparison with caries-associated bacteria. Design: Bifidobacterium lactis, Bifidobacterium longum, Bifidobacterium animalis, Bifidobacterium dentium, Lactobacillus acidophilus, Lactobacillus casei, Actinomyces israelii, Streptococcus sobri...

Objective: The aim was to investigate the effect of maltodextrin and sucrose association on the acidogenic and adherence profiles of cariogenic bacteria. Design: Streptococcus mutans (S. mutans) and Lactobacillus casei (L. casei) were cultivated in culture medium containing maltodextrin, sucrose, maltodextrin-sucrose mixture or glucose. Analyses...

This study aimed to evaluate the effect of fluoridated dentifrice (FD) and mouthwash (FM) under different treatment regimens on root caries (RC) inhibition. Dual-species biofilms formed by Streptococcus mutans and Lactobacillus casei were grown on the surface of bovine root dentine slabs which were exposed during 3 consecutive days to one of the fo...

The aim of this systematic literature review was to investigate whether the incorporation of antimicrobial agents into dental restorative materials truly exerts an antimicrobial effect against common cariogenic bacteria (primary outcome); and whether the inclusion of antimicrobial agents is able to prevent caries around restorations (secondary outc...

RESUMO Este estudo teve como objetivo avaliar o efeito da 8-hidroxiquinolina (HQ) contra alguns patógenos envolvidos na cárie dentária e estomatite, como o Streptococcus mutans (SM), Lacobacillus casei (LC) e Candida albicans (CA). Alíquotas de suspensões padronizadas de cada microrganismo foram uniformemente colocadas em placas de ágar de sangue (...

Streptococcus mutans is specifically suppressed by intensive treatment with chlorhexidine gel, but the time for recolonization and the effect on other oral bacteria are not totally clear. In this study, recolonization of mutans streptococci was evaluated in nine healthy adult volunteers, who were highly colonized with this microorganism. Stimulated...

The aim of this study was to evaluate both sucrose and fluoride concentrations and time of biofilm formation on enamel carious lesions induced by an in vitro artificial-mouth caries model. For Study 1, biofilms formed by streptococci and lactobacilli were grown on the surface of human enamel slabs and exposed to artificial saliva containing 0.50 or...

Purpose Synthesize polydioxanone (PDS) based drug delivery systems (hereafter referred to as matrices) containing vancomycin (VANC) and/or rifampicin (RIF), and investigate its effect on the inhibition of biofilm growth comprised of osteomyelitis (OM) associated pathogens. Materials and Methods PDS matrices were prepared by electrostatic spinning...

The purposes of this study were to fabricate biodegradable polydioxanone (PDS II®) electrospun periodontal drug delivery systems (hereafter referred to as matrices) containing either metronidazole (MET) or ciprofloxacin (CIP) and to investigate the effects of antibiotic incorporation on both periodontopathogens and commensal oral bacteria. Fibrous...

The aim of this study was to compare the genotypic diversity and virulence traits of Streptococcus mutans isolated from carious dentin before and after partial dentin caries removal (PDR) and sealing. Carious dentin samples were obtained three months before and after the PDR and cavity sealing. Up to seven isolates of each morphological type of S....

The human skin not only provides passive protection as a physical barrier against external injury, but also mediates active surveillance via epidermal cell surface receptors that recognize and respond to potential invaders. Primary keratinocytes and immortalized cell lines, the commonly used sources to investigate immune responses of cutaneous epit...

Cell exfoliation is a characteristic feature of epithelia covering the external surface and the internal cavities of the body. While the benefit of cytology in infections and cancer diagnosis is well recognized, the clinical use of epithelial cells obtained from body fluids is relatively unexplored. As the first cells to encounter microbes, the epi...

Objective: Study aims were to evaluate the ability of objectively assess surface reflection [reflectance (amplitude, %)], roughness (Ra, µm), and Quantitative Light-induced Fluorescence [QLF: DQ (%×mm2)] with dehydration in the assessment of caries lesion activity. Method: 195 ground/polished 3x3x2mm sound human-enamel-specimens were divided into...

The aims of this study were to describe and validate an in vitro multispecies microbial biofilm model for caries development by evaluating the effects of varying medium concentration of sucrose (0.5 and 1.0%) and fluoride (0.4, 0.8 and 1.0 ppm F) in study 1, and calcium (1.0 and 2.0 mM Ca) in study 2. Defined-multispecies biofilms, formed by Lactob...

Sporotrichosis is an infection caused by the dimorphic fungus Sporothrix schenckii. Toll-like receptors (TLRs) play an important role in immunity, since they bind to pathogen surface antigens and initiate the immune response. However, little is known about the role of TLR-2 and fungal surface antigens in the recognition of S. schenckii and in the s...

Prolonged systemic antimicrobial therapy may lead to bacterial strain resistance, stimulating the design of effective drug-containing membranes capable of promoting a successful reduction and/or elimination of pathogens present in the gingival fluid and periodontal pocket. These membranes may become exposed to the oral cavity and pose a disturbance...

Objective: To evaluate the effect of different microbial-induced demineralization cycles on human enamel specimens by a multi-species Microbial Model. Method: Three groups of seven ground/polished 3×3×2mm human enamel blocks each were used in this study. They were all covered with nail varnish, except one 2x1mm window, which was exposed to the mi...

Objective: To compare the effect of sucrose and fluoride concentrations on surface characteristics of demineralized enamel developed by five species [Actinomyces naeslundii (ATCC 19039), Lactobacillus casei (ATCC 4646), Streptococcus mutans (ATCC 700610 – UA159), Streptococcus salivarius (ATCC 25975), Streptococcus sanguinis (ATCC BAA-1455)] using...

The development of microbial biofilm models to study carious lesions initiation and progression are needed to mimic in vivo caries under laboratory conditions. Objectives: This study aimed to develop a microbial 4-species-consortia biofilm model to study enamel caries lesion development under constant and intermittent sugar exposure. Methods: B...

The oral cavity harbors several Streptococcus mutans genotypes, which could present distinct virulence properties. However, little is known about the diversity and virulence traits of S. mutans genotypes isolated in vivo under controlled conditions of high cariogenic challenge. This study evaluated the genotypic diversity of S. mutans isolated from...

Objectives: Oral cavity harbors several Streptococcus mutans genotypes, which could present distinct virulence properties. However, little is known about the virulence traits of genotypes isolated under in vivo controlled conditions of high cariogenic challenge. This study aimed to evaluate the aciduricity and acidogenicity of S. mutans genotypes i...

The effect of infant formulas sweetened or not with sucrose on primary enamel demineralization and dental biofilm is not known. This study's purpose was to evaluate the effect of infant formula and sucrose association on demineralization of primary enamel and dental biofilm formed. A cross-over, split-mouth, and blind in situ study was conducted du...

Streptococcus mutans has been considered one of the main etiological agents of dental caries and the genotypic diversity rather than its salivary counts may be considered as a virulence factor of this bacterium. For genotyping with polymerase chain reaction (PCR) with arbitrary primers, several primers have been used in order to improve complexity...

Modelos in vitro para avaliação da reatividade do fluoreto (F) devem apresentar resposta dose-efeito. Dessa forma, o objetivo desse estudo foi avaliar a relação dose-resposta do fluoreto presente em solução aquosa com o esmalte dental bovino. Cento e vinte blocos de esmalte bovino (5 × 5 × 2 mm), 60 hígidos e 60 com lesão artificial de cárie, foram...

In situ dental biofilm composition under sugar exposure is well known, but sugar effect on the genotypic diversity of S. mutans in dental biofilm has not been explored. This study evaluated S. mutans genotypic diversity in dental biofilm formed in situ under frequent exposure to sucrose and its monosaccharide constituents (glucose and fructose). Sa...

The aim of this study was to investigate the temporal relationship between changes in biofilm composition and enamel demineralization following exposure to sucrose. A crossover blind study was conducted in situ in three phases, during which 12 volunteers, divided into three groups, subjected enamel slabs 8 times/day to water (negative control), 10%...