Preparation and characterization of NaF/Chitosan supramolecular complex and their effects on prevention of enamel demineralization.

Fluoridated mouthrinse is indicated for individuals with high risk of caries. Chitosan (Chit) exhibits antibacterial properties, but little is known about its effects on enamel when combined with sodium fluoride (NaF) to form NaF/Chit supramolecular complexes. In our study, NaF/Chit supramolecular complexes structured as microparticles were synthetized and characterized, and their effects on human enamel were evaluated after cariogenic challenge simulating the daily mouthrinse use. Initially, NaF/Chit complex formation was investigated based on several titrations by measuring the zeta potential, electrical conductivity (κ), hydrodynamic diameter (Dh), viscosity (η) and heat flow (by isothermal titration calorimetry) against the molar ratio [NaF]/[Chitmonomer], which allowed us to identify the interactions between Chit-NaF with a stoichiometry of approximately 0.68. Spontaneous microparticle formation was observed. Samples of enamel blocks were prepared and divided into eight groups (n = 10/group): (i) 0.2% Chit; (ii) 0.2% NaF; (iii) 0.2% NaF/Chit suspension; (iv) 0.2% acetic acid; (v) 0.05% Chit; (vi) 0.05% NaF; (vii) 0.05% NaF/Chit suspension; and (viii) 0.05% acetic acid. Cariogenic challenge was performed in each sample by cycling in demineralization and remineralization solutions for 7 days. Before each demineralization cycle, the corresponding substances were passively applied daily for 90 s, even in groups with 0.02% concentration. After 7 days, samples were examined for Knoop hardness (KHN) measurements. The data were analyzed by repeated-measures ANOVA and Tukey tests (α = 0.05). The 0.2% NaF and 0.2% NaF/Chit groups showed higher KHNpost-challenge values than the other groups. The 0.2% NaF/Chit microparticle suspension reduced the enamel hardness loss after cariogenic challenge as effectively as the 0.2% NaF solution and demonstrated potential for use in a formulation with anti-caries effects.

Association of Oral Health-Related Quality of Life with the Longevity of ART-Restorations in Children

ABSTRACT Objective: To evaluate the association of oral health-related quality of life (OHRQoL) with the longevity of ART-restorations in children after 18 months. Material and Methods: A longitudinal clinical study with 62 six- to seven-year-old children, both genders, 31 of whom underwent four weeks of oral health education strategy (OHES) followed by ART (GOHES+ART) and the others only ART (GART). The Brazilian short-version of the Child Perceptions Questionnaire (16-CPQ8-10) was used to evaluate the OHRQoL and the perception of change in oral health was assessed by a single question. Data was analyzed using Mann-Whitney, Wilcoxon and Friedman's tests. Results: After 18 months, GOHES+ART reported a greater impairment on OHRQoL, mainly in oral symptoms domain (p<0.05). In this period, greater impairment of oral symptoms was reported in children with failed restorations and with treatment considered to have a minor failure (p<0.05). In inter-group analysis, the GOHES+ART, with 2 to 4 restorations, Class I, of small size, located in the upper arch and with a smaller failure, reported more oral symptoms than the GART. Conclusion: In the long-term, children submitted to OHES followed by ART reported more oral symptoms. Factors such as number, class, size and location of the restorations need to be considered for the implementation of an efficient and effective oral health program, as well as for greater longevity of ART-restorations.

Which self-etch acidic composition may result in higher dental bonds at the long-term? A network meta-analysis review of in vitro studies.

OBJECTIVES: This review evaluated the effects of the acidic composition of self-etch (SE) adhesives at the long-term bond strengths to dentin and enamel. DATA: The review followed the PRISMA Extension Statement for network meta-analysis. Studies were identified by a systematic search in PubMed, Web of Science, and Scopus databases. STUDY SELECTION: The inclusion criteria were in vitro studies that evaluated bond strength data of samples analyzed at both immediate and long-term (after aging simulation) periods and that were bonded to sound dentin/enamel using SE adhesives, with at least one group of adhesives being based on 10-MDP (10-methacryloyloxy-decyl-dihydrogen-phosphate; control) and the other group being comprised of alternative acidic monomers. Statistical analyses were conducted using two methods: standard pairwise meta-analysis (SPMA) and Bayesian network meta-analysis (NMA). Heterogeneity was assessed by using the Cochran Q test and I2 statistics. RESULTS: From 5220 studies identified, 87 met the eligibility criteria and 83 were meta-analyzed. Seventeen adhesives were based on 10-MDP and 44 systems were based on alternative acids. The resin-dentin/enamel bonds were predominantly reduced after aging (∼84% of cases). From the SPMA findings, the following acidic compositions showed lower bond strength values (effect size: mean difference [MD] with 95% confidence interval [95% CI]) than 10-MDP: 4-META (MD -4.99, 95% CI: -7.21, -2.78; p<0.001); sulfonic acids (MD -9.59, 95% CI -12.19, -6.98; p<0.001); unspecified phosphate esters (MD -8.89, 95% CI -17.50, -0.28; p = 0.04); or mixed acids (MD -11.0, 95% CI -13.62, -8.38; p<0.001). The dental bonds were benefited from the presence of 10-MDP upon longer aging (>6 months). From the NMA probabilistic findings, adhesives based on 10-MDP and phosphonic acids ranked as having the best and the worst bonding potential to dentin, respectively. More than one composition (phosphonic acids and mixed acids) ranked similarly to 10-MDP in enamel. The studies scored as having moderate risk of bias (58.6%), followed by low (39.1%) and high (2.3%) risk of bias. CONCLUSION: 10-MDP is an outstanding acidic monomer that contributes to higher bonds to dentin at the long-term. In enamel, there is no evidence that one acidic composition prevails over the other. CLINICAL SIGNIFICANCE: The acidic composition of SE adhesives affects the resistance of dental bonds after simulated aging, with 10-MDP playing a significant role in the adhesion to dentin but not to the enamel. REGISTRATION NUMBER: This report is registered at the Open Science Framework (osf.io/urtdf).

Possible Relationship Between the Oral and Gut Microbiome, Caries Development, and Obesity in Children During the COVID-19 Pandemic.

The COVID-19 pandemic has brought health damage and socioeconomic disruptions, together with lifestyle disorders around the world. Children are one of the most commonly affected, mainly due to social isolation and changes in eating habits and physical activities. This way, the risk of weight gain and obesity is possibly enhanced, as well as poor oral hygiene conditions and early childhood caries (ECC) development during the lockdown. In children under 6 years of age, ECC is defined as carious lesions in one or more primary teeth, with or without cavitation. Importantly, alterations in the oral microbiome caused by changes in children lifestyles have much more than a local impact on oral tissues, interplaying with the gut microbiome and influencing systemic environments. Recent studies have been exploring the oral health conditions, eating habits, and weight gain in the childhood population during the COVID-19 pandemic; however, there is a lack of information concerning the association among oral and gut microbiome, dental caries, and obesity in the COVID-19 era. In this context, this review aimed at analyzing a possible relationship between the oral and gut microbiome, caries, and obesity in children during the COVID-19 pandemic.

Risk Factors for the Incidence of Dental Caries in Low, Very Low, and Extremely Low Birth Weight Children: A Cohort Study

Abstract Objective: To assess the incidence of caries in a two-year period among low birth weight (LBW), very low birth weight (VLBW), and extremely low birth weight (ELBW) children considering socioeconomic indicators, dietary factors and oral hygiene. Material and Methods: A convenience sample was formed of 42 low birth weight children aged two to five years at baseline. Two examiners diagnosed caries using the World Health Organization criteria. Birth weight, socioeconomic indicators and diet were collected from medical records and questionnaires. Binomial models were used to estimate unadjusted and adjusted rate ratios (RR) and respective 95% confidence intervals for the factors evaluated. Results: Thirty-six children were re-examined after two years. The incidence of dental caries was 36.7%. The dmft index was 0.44 (±1.25) at baseline and increased to 1.36 (±3.85) at follow-up. VLBW children (1,000 to 1,500 g) (RR=0.23; 95%CI: 0.08-0.72) and LBW children (1,500 to 2,500 g) (RR=0.06; 0.01-0.55) had fewer carious lesions compared to ELBW children (<1,000 g). Carious lesions were more frequent among children with a lower income (RR=6.05; 1.05-34.84) and less frequent among those who did not consume sweetened juice, tea or yogurt (RR: 0.21; 0.07-0.62). Conclusion: An inverse dose-response relation was found between birth weight and the incidence of caries. A lower income and the consumption of sweetened beverages were risk factors for the development of caries (AU).

Synthesis of a chitosan nanoparticle suspension and its protective effects against enamel demineralization after an in vitro cariogenic challenge.

OBJECTIVE: Our study aims to synthesize, characterize, and determine the effects of a ChNPs suspension on human enamel after cariogenic challenge via pH-cycling. METHODOLOGY: ChNPs were synthesized by ion gelation and characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering. Forty enamel blocks were divided into four groups (n=10/group): (i) ChNPs suspension; (ii) chitosan solution; (iii) 0.05% sodium fluoride (NaF) solution; and (iv) distilled water. Specimens were exposed to cariogenic challenge by cycling in demineralization solution (3 h) and then remineralized (21h) for 7 days. Before each demineralization cycle, the corresponding solutions were passively applied for 90 s. After 7 days, specimens were examined for surface roughness (Ra) and Knoop hardness (KHN) before and after the cariogenic challenge; % KHN change (variation between initial and final hardness), and surface topography by an optical profilometer. The data were analyzed by repeated-measures ANOVA, One-way ANOVA, and Tukey tests (α=0.05). RESULTS: TEM images showed small spherical particles with diameter and zeta potential values of 79.3 nm and +47.9 mV, respectively. After the challenge, all groups showed an increase in Ra and a decrease in KHN values. Optical profilometry indicated that ChNPs- and NaF-treated specimens showed uneven roughness interspersed with smooth areas and the lowest %KHN values. CONCLUSION: The ChNPs suspension was successfully synthesized and minimized human enamel demineralization after a cariogenic challenge, showing an interesting potential for use as an oral formulation for caries prevention.

Analysis of Chlorhexidine Modified Cement in Orthodontic Patients: A Double-Blinded, Randomized, Controlled Trial.

OBJECTIVES: The aim of this study was to evaluate the microbiological and mechanical properties of glass ionomer cement (GIC) modified by chlorhexidine (CLX) for the purpose of cementing bands to the teeth of orthodontic patients. MATERIALS AND METHODS: Ten patients, between the ages of 19 and 33 years, in the initial stage of orthodontic treatment, were randomly designated to two groups using the split-mouth design (n = 10). One group (GICEX) had bands cemented with GIC modified by CLX and a Control group (GIC), evaluated at time intervals before (T0), 3 months (T3), and 6 months (T6) after cementation. Total microbiological counts were performed, and color stability of tooth enamel, salivary pH, and the adhesive remnant index (ARI) were evaluated. STATISTICAL ANALYSIS: The Friedman and Dunn's tests, Mann-Whitney, one-way analysis of variance, and Tukey, and paired and non-paired t-tests (p< 0.05) were used. RESULTS: In T3, there was evidence of significant reduction in the quantity of colony forming unit (CFU) in GICEX group in comparison with the Control (p = 0.041). In T6, the quantity of CFU was similar to the quantity in T3 and significantly different to control (p = 0.045); Control group demonstrated a similar quantity of CFU between the experimental time intervals (p = 0.066). Salivary pH demonstrated significant difference only between the time intervals T0 and T6 (p = 0.022). The tooth enamel color (p = 0.366) and ARI (p = 0.343) values demonstrated no significant changes. CONCLUSION: The incorporation of CLX into GIC demonstrated effective antibacterial action, allowed a good bond of the cement to the enamel, a high rate of survival of the bands, did not change the color of the tooth enamel, and maintained the salivary pH at physiological levels.

A higiene bucal de bebês edêntulos e sua influência na microbiota bucal: os profissionais de saúde devem preconizá-la? ­ revisão crítica / Oral hygiene in edentulous infants and its influence on oral microbiota: should the health professionals recommend it? ­ a critical review

Introdução: A indicação de higiene bucal em bebês edêntulos entre os profissionais de saúde ainda é controversa, sendo necessária a busca científica sobre esta indicação e a padronização da informação. Objetivo: Investigar criticamente as evidências relacionadas a indicação da higiene bucal para bebês edêntulos. Métodos: A busca de artigos foi realizada nas bases de dados PubMed, LILACS e Google Scholar, de modo a avaliar a seguinte pergunta: "A higienização da cavidade bucal de bebês edêntulos pode influenciar a microbiota bucal?". Uma busca em 8 livros de Odontopediatria também foi realizada. Resultados: Foram encontrados 317 artigos (167-PubMed, 146-Google Scholar e 4-LILACS). Não foram encontrados estudos primários que avaliaram o efeito da higiene bucal em bebês edêntulos na microbiota, impossibilitando a condução de revisão sistemática. Assim, para a revisão foram incluídos 6 estudos que investigaram micro-organismos na cavidade bucal de bebês edêntulos e o papel das imunoglobulinas salivares. Dentre os livros avaliados, somente 4 indicaram a higiene bucal em bebês edêntulos. Conclusão: Diante dos dados analisados, não existem estudos primários que avaliaram o efeito da higienização na microbiota bucal de bebês edêntulos. Torna-se relevante a condução de estudos clínicos para obtenção de evidências científicas sobre a indicação ou não da higienização da cavidade bucal de bebês edêntulos.

Introduction: The indication of oral hygiene in edentulous babies is still controversial among health professionals, being necessary the search of this recommendation and the standardization of information. Objective: To inves-tigate critically the evidence related to the indication of oral hygiene for edentulous babies. Methods: The search for articles was performed in the PubMed, LILACS and Google Scholar databases, in order to assess the following question: "Can oral cavity hygiene of edentulous babies influence oral microbiota?" A search in 8 books of Pediatric Dentistry was also performed. Results: 317 articles were found (167-PubMed, 146-Google Scholar and 4-LILACS). There were no primary studies that evalu-ated the effect of oral hygiene of edentulous infants on microbiota, which impair the conduction of a systematic review. Thus, it was included for this review six studies that investigated microorganisms in the oral cavity of edentulous infants and the role of salivary immunoglo- bulins. Among the textbooks evaluated, only 4 indicated the oral hygiene in edentulous infants. Conclusion:According to the data, there are no primary studies that assessed the effect of oral hygiene in the oral microbiota of edentulous babies. It is relevant to conduct clinical studies in order to obtain scientific evidence about the indication or no of the oral hygiene in edentulous babies

Effectiveness of Secondary Alveolar Bone Graft on Canine Eruption: Systematic Review.

There are controversies related to the effects of bone grafts on tooth eruption and impaction in patients with cleft lip and palate. The aim of this systematic review was to evaluate the effectiveness of bone grafting on eruption of canines in patients with unilateral cleft lip and palate (UCLP). An electronic search was conducted in six electronic databases and gray literature, without limitations on year of publication or language. The primary outcome was the increase in rate of canine eruption; the secondary outcomes were success of the bone graft, canine impaction due to agenesis of the lateral incisor, and effect of orthodontic treatment before and after bone grafting. The risk of bias was analyzed by means of the tool Cochrane risk of bias in nonrandomized controlled trials (NRCTs) of interventions (ROBINS-I). The certainty of the evidence was assessed for outcomes reported through a narrative synthesis using grading of recommendations, assessment, development and evaluation (GRADE) approach. Four NRCTs were included, with a total of 360 patients, 283 UCLP and 77 bilateral cleft lip and palate (BCLP). The studies reported association between the increase in the rate of tooth eruption and bone graft with very low certainty of evidence, and greater experience of surgical success, with low certainty of evidence. The majority of the studies found an association between increase in the rate of canine impaction and agenesis of the lateral incisor, with very low certainty of evidence. There was very low certainty of the efficacy of secondary alveolar bone grafting for increasing the rates of eruption and reducing impaction of the maxillary canine.

Weight-loss and surface roughness of enamel after microabrasion procedure with different agents / Perda de peso e rugosidade da superfície do esmalte após procedimento de microabrasão com diferentes agentes

Introduction: Enamel microabrasion is achieved by abrasion of the enamel surface and it is a quick, practical and efficient procedure. Objective It was assessed the weight loss and surface aspect of enamel after microabrasion procedures with commercial and mixtures made in-office. Material and method Eighty bovine incisors were divided into four groups (n=10): OpalustreTM (6.6% HCl + silicon carbide); Whiteness RMTM (6% HCl + silicon carbide); 37% H3PO4 + pumice and 10% HCl + pumice. Treatment was performed by 15 applications of 10s duration. The enamel weight loss was determined by the difference in weight before and after the microabrasion. The surfaces were analyzed by a surface roughness equipment and scanning electron microscopy. Data were submitted to paired-T test, one-way ANOVA and Tukey tests (α=0.05). Result It was observed significantly weight loss for all groups. The difference in weight loss ranged from 0.037±0.012 for group 37% H3PO4 and from 0.054±0.009 for group 6,6% HCl. There was a significant increase in surface roughness for all groups and 10% HCl group showed the lower results (0.65±0.09). It was observed different patterns of enamel morphology by SEM images. Conclusion The in-office mixtures resulted in the lowest enamel structure loss (37% H3PO4) and the lowest surface roughness (10% HCl).

Introdução: A microabrasão do esmalte é realizada através da abrasão da superfície do mesmo, apresentando-se como um procedimento rápido, prático e eficiente. Objetivo Avaliar a perda de peso e o aspecto superficial do esmalte após procedimentos de microabrasão com agentes comerciais e não comerciais. Material e método Oitenta incisivos bovinos foram divididos em quatro grupos (n = 10): OpalustreTM (6,6% HCl + carboneto de silício); Whiteness RMTM (6% HCl + carboneto de silício); 37% H3PO4 + pedra-pomes e 10% HCl + pedra-pomes. O tratamento foi realizado em 15 aplicações de 10s de duração. A perda de peso do esmalte foi determinada pela diferença de peso antes e depois da microabrasão. As superfícies foram analisadas por equipamento de rugosidade superficial e microscopia eletrônica de varredura. Os dados foram submetidos ao teste T-pareado, ANOVA one-way e teste de Tukey (α = 0,05). Resultado Foi observada perda de peso significativa para todos os grupos, a diferença na perda de peso variou de -0,037±0,012 para o grupo 37% H3PO4 a -0.054±0.009 para o grupo 6.6% HCl. Houve um aumento significativo na rugosidade da superfície para todos os grupos e o grupo 10%HCl apresentou os resultados mais baixos (0,65±0,09). Foram observados diferentes padrões de morfologia do esmalte por meio de imagens MEV. Conclusão Os agentes não comerciais resultaram na menor perda de estrutura do esmalte (37% H3PO4) e na rugosidade superficial (10% HCl).

Synthesis of a chitosan nanoparticle suspension and its protective effects against enamel demineralization after an in vitro cariogenic challenge

Abstract Objective Our study aims to synthesize, characterize, and determine the effects of a ChNPs suspension on human enamel after cariogenic challenge via pH-cycling. Methodology ChNPs were synthesized by ion gelation and characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering. Forty enamel blocks were divided into four groups (n=10/group): (i) ChNPs suspension; (ii) chitosan solution; (iii) 0.05% sodium fluoride (NaF) solution; and (iv) distilled water. Specimens were exposed to cariogenic challenge by cycling in demineralization solution (3 h) and then remineralized (21h) for 7 days. Before each demineralization cycle, the corresponding solutions were passively applied for 90 s. After 7 days, specimens were examined for surface roughness (Ra) and Knoop hardness (KHN) before and after the cariogenic challenge; % KHN change (variation between initial and final hardness), and surface topography by an optical profilometer. The data were analyzed by repeated-measures ANOVA, One-way ANOVA, and Tukey tests (α=0.05). Results TEM images showed small spherical particles with diameter and zeta potential values of 79.3 nm and +47.9 mV, respectively. After the challenge, all groups showed an increase in Ra and a decrease in KHN values. Optical profilometry indicated that ChNPs- and NaF-treated specimens showed uneven roughness interspersed with smooth areas and the lowest %KHN values. Conclusion The ChNPs suspension was successfully synthesized and minimized human enamel demineralization after a cariogenic challenge, showing an interesting potential for use as an oral formulation for caries prevention.

Effect of hydrochloric acid commercial presentation for microabrasion technique on loss of enamel structure and surface / Efeito da apresentação comercial de ácido clorídrico para técnica de microabrasão na perda de estrutura e superfície do esmalte

Introdução: A técnica de microabrasão pode ser realizada através de pasta pronta para uso, disponível comercialmente, ou o profissional pode manipulá-la no consultório. Objetivo: Verificar o efeito da apresentação comercial do ácido clorídrico a 10% na manipulação de pasta para microabrasão sobre a superfície do esmalte. Metodologia: Foram selecionados incisivos bovinos e divididos em dois grupos, de acordo com a apresentação comercial do ácido clorídrico (líquido ou em gel). O tratamento foi realizado através de dez aplicações com 10s de duração cada, intercaladas por lavagem de 10s. Vinte incisivos (n=10) foram utilizados para se determinar a perda de estrutura do esmalte. Cada amostra foi pesada, em balança analítica, antes e após submissão à microabrasão. Outras 20 amostras (n=10) foram utilizadas para determinação da rugosidade superficial média (Ra) utilizando-se um rugosímetro. Três amostras de cada grupo do experimento anterior foram selecionadas, aleatoriamente, e outras três amostras adicionais foram preparadas como controle (baseline) para análise em MEV. Resultados: Verificou-se diferença estatística significativa entre a massa final e a inicial e rugosidade superficial das amostras, independente da apresentação comercial do ácido. Nas imagens de MEV observou-se presença de superfície regular para o grupo controle (baseline). Nas demais imagens verificou-se superfície com considerável irregularidade e dissolução discreta do esmalte. Conclusões: O tratamento realizado causou perda significativa de estrutura e aumentou a rugosidade superficial dos espécimes, independente da apresentação comercial do ácido e sem apresentar diferença entre os grupos ao final. A apresentação comercial do ácido não parece ser um fator a interferir no tratamento. (AU)

Introduction: The microabrasion technique can be performed using a commercially available paste, or the dentist can prepare it in his office. Objective: To verify the effect of hydrochloric acid commercial presentation in the handling of microabrasion paste on the enamel surface. Methodology: Bovine incisors were divided into two groups, according to the commercial presentation of 10% hydrochloric acid (liquid or gel). The treatment was carried out through ten applications of 10 s duration each, intercalated with a 10s wash. Twenty teeth (n=10) were used to determine the loss of enamel structure. Each sample was weighed on an analytical balance before and after submission to microabrasion. Another 20 teeth (n=10) were used to determine the average surface roughness (Ra) using a rugosimeter. Three samples from each group of the previous experiment were selected, randomly, and another three additional samples were repared as a control (baseline) for SEM analysis. Results: There was a statistically significant difference between the final and initial mass and the surface roughness of the samples, regardless of the acid commercial presentation. In the SEM images, a regular surface was observed for the control group (baseline). In the other images, there was a surface with considerable irregularity and a slight dissolution of the enamel. Conclusions: The treatment carried out. (AU)

Effect of Orthodontic Treatment on Tooth Autotransplantation: Systematic Review of Controlled Clinical Trials.

This systematic review was focused on evaluating tooth autotransplantation, considering its impacts on the teeth, bone, soft tissues, and aesthetics in orthodontic patients. A bibliographic search was conducted without limitations on year of publication or language in the databases of PubMed, Web of Science, Scopus, Medline Complete, Cochrane, Clinical Trials, and Trials Central. For triage of articles, indications, surgical planning, orthodontic movement, risk factors for treatment, and long-term follow-ups were considered. For outcomes, the results with reference to teeth, alveolar bone, periodontal tissues, and esthetic satisfaction were considered. Risk of bias was evaluated using the methodological index for nonrandomized studies-MINORS. The results showed 10 controlled clinical trials, and no randomized clinical trials were found. The selected studies included 715 patients and 934 autotransplanted teeth among which there were premolars, molars, and anterior teeth evaluated in the long term, indicating that orthodontics associated with autotransplantation indicated a result that was generally clinically acceptable. The quality of the set of evidence was considered medium due to the presence of different methodological problems, risk of bias, and significant heterogeneity in the evaluated studies. There was a sufficient body of evidence that justified autotransplantation in patients who needed orthodontic movement. In teeth, there was an increase in root resorption influenced by orthodontics, but without impacting on the general clinical result in the long term. Bone and periodontal tissue do not appear to be affected by orthodontics. The patient's aesthetic satisfaction was not considered in the studies.

In Vivo Biocompatibility, Mechanical, and Antibacterial Properties of Cements Modified with Propolis in Different Concentrations.

OBJECTIVES: The focus of this triple-blind randomized study was to evaluate the mechanical properties, antibacterial effect, and in vivo biocompatibility of glass ionomer cements (GICs) modified with ethanolic extracts of propolis (EEP). MATERIALS AND METHODS: For biocompatibility tests, 135 male Wistar rats were used and divided into nine groups: Group C (control, polyethylene), Groups M, M10, M25, M50 (Meron; conventional, and modified with 10%, 25%, 50% EEP, respectively), Groups KC, KC10, KC25, KC50 (Ketac Cem; conventional, and modified with 10%, 25%, 50% EEP, respectively). The tissues were analyzed under an optical microscope for different cellular events in different time intervals. Shear bond strength test (SBST) on cementation of metal matrices (n = 10, per group), adhesive remnant index (ARI) in bovine incisors (n = 10, per group), and antibacterial properties by the agar diffusion test (n = 15, per group) were analyzed. STATISTICAL ANALYSIS: Data were analyzed by Kruskal-Wallis test followed by Dunn, and one-way analysis of variance test followed by Tukey's test (p < 0.5). RESULTS: Morphological evaluation demonstrated intense inflammatory infiltrate in Groups M10 and KC10 in the time intervals of 7 (p = 0.001) and 15 (p = 0.006) days. Multinucleated giant cells were shown to be more present in Group M1, with statistical difference from Control and KC50 Groups in the time interval of 7 days (p = 0.033). The SBST showed no statistical significance among the groups (p > 0.05). Antibacterial property showed a statistically significant difference between Meron and Meron 50%-EEP Groups, and between Ketac and Ketac 50%-EPP Groups (p = 0.001). CONCLUSIONS: The intensity of histological changes resulting from the cements was shown to be inversely proportional to the concentration of propolis added; Ketac 50%-EPP was the concentration that had the most favorable biocompatibility results. Addition of EEP to GIC did not negatively change the SBST and ARI. Antibacterial property demonstrated a concentration-dependent effect.

Antimicrobial, mechanical and biocompatibility analysis of chlorhexidine digluconate-modified cements.

BACKGROUND: The focus of this study was to evaluate the antimicrobial, mechanical properties and biocompatibility of glass ionomer (GICs) modified by Chlorhexidine (CHX). MATERIAL AND METHODS: For biocompatibility, 105 male Wistar rats were used, divided into 7 groups (n=15): Group C (Control,Polyethylene), Groups M, M10, M18, and Groups RL, RL10, RL18 (M-Meron and RL-Riva Luting: conventional, and modified with 10%, and 18% CHX, respectively). The tissues were analyzed under optical microscope for different cellular events and time intervals. Antibacterial effect and Shear Bond Strength Test (SBST) were also analyzed. Biocompatibility was analyzed by the Kruskal-Wallis and Dunn tests; SBST one-way ANOVA and Tukey test (P<0.05). For the antibacterial effect, the Kruskal-Wallis and Friedman, followed by Dunn (P<0.05) tests were used. RESULTS: Morphological study of the tissues showed inflammatory infiltrate with significant differences between Groups C and RL18, in the time intervals of 7(P=0.013) and 15(P=0.032) days. The antimicrobial effects of the cements was shown to be CHX concentration-dependent (P=0.001). The SBST showed no significant difference between the Groups of Meron cement (P=0.385), however, there was difference between Group RL and Groups RL10 and RL18 (P=0.001). CONCLUSIONS: The addition of CHX did not negatively influence the SBST. Meron-CHX-10% was the most biocompatible, and Riva-CHX-18% had more influence on the inflammatory process and presented slower tissue repair. Key words:Glass ionomer, chlorhexidine, biocompatibility, antimicrobial properties, microscope.

In Vitro Effect of Acidic Challenges on the Physical Properties of Dental Prosthesis Artificial Teeth

Abstract Objective: To evaluate the effect of immersion and acid challenge with cola drink on color change (ΔE), Vickers hardness (VHN) and surface roughness (Ra) of artificial acrylic resin teeth. Material and Methods: The artificial teeth were divided into 6 groups (n= 8): TC (Trilux/Control), BC (Biotone/Control), TAC (Trilux/Acid challenge), BAC (Biotone/Acid challenge), TI (Trilux/Immersion) and BI (Biotone/Immersion). The teeth were embedded in acrylic resin and the labial side was serially polished to provide appropriate flat surface. The samples of TC, BC, TI, BI groups were immersed in artificial saliva and cola drink (coke) for 7 days, respectively. The acid challenge was performed with immersion of samples in coke for 5 min, and subsequently immersion in artificial saliva for 2h. This cycle was repeated at 4 times/day, during 7 days. The tests of VHN, ΔE and Ra were analyzed before and after the challenge and immersion groups. Data was analyzed by ANOVA, Tukey and T test (α = 0.05). Results: There was no difference in Ra values between groups after treatments. However, there was a decrease in VHN for all groups. BI (19.2 ± 0.3) presented significantly lower hardness than BAC (19.5 ± 0.9) and BC (20.2 ± 0.5). Groups BI (2.18 ± 0.41) and TI (1.50 ± 0.43) had statistically higher ΔE compared to the other groups. Conclusion: The hardness of resin teeth decreased after acid challenges, but the roughness surface was not affected. The color was more affected by the times of exposure in cola beverage and remineralization in artificial saliva, which were associated to the material degradation (AU).

Efficacy of Topical Anesthetics in Pain Perception During Mini-implant Insertion: Systematic Review of Controlled Clinical Trials.

The focus of this systematic review is to assess the efficacy of several commonly utilized anesthetic techniques for reducing pain during the placement of mini-implants. An electronic search was conducted in the databases PubMed, Scopus, Web of Science, Medline Complete, Cochrane, Trials Central, and Clinical Trials, without limitations on year of publication or language. Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) were considered. Two reviewers of articles independently evaluated the results of the study, and the risk of bias of included articles was evaluated according to the Cochrane Scale. Five eligible articles (3 RCTs and 2 CCTs) were included. The quality of the body of evidence was considered low because of the presence of multiple methodological problems, high risks of bias, and heterogeneity in the articles included. There was evidence that the efficacy of the analgesia of infiltrative anesthesia was most effective in promoting a lower perception of pain compared to the other anesthetic agents, although an injection was required. Among topical anesthetics, compound topical anesthetics with 20% lidocaine were more effective than compound topical anesthetics with low lidocaine concentration and conventional topical anesthetic with 20% benzocaine.

Synthesis and characterization of TPP/chitosan nanoparticles: Colloidal mechanism of reaction and antifungal effect on C. albicans biofilm formation.

In the present study chitosan (Chit) nanoparticles were synthetized by the ionic gelation process, using tripolyphosphate (TPP) as crosslinking agent. The TPP/Chit nanoparticle formation was evaluated by titrations, measuring electrical conductivity (k), zeta potential (ZP), hydrodynamic diameter (Dh), viscosity (η) and heat by isothermal calorimetry (ITC). The antifungal effects were evaluated by C. albicans time-kill assays, inhibition of C. albicans initial adhesion and biofilm formation in comparison with nystatin and chitosan. Conductometric titration exhibited a typical precipitation profile, with an inflection at molar ratio of [TPP]/[Chitmon] ≈ 0.3, suggesting a 1:3.3 stoichiometry. The highest Dh, ZP and η values were shown at the beginning of titrations, due to the intramolecular repulsion between Chit-Chit. With addition of TPP, the values showed gradual reduction, with an intermediary transition at [TPP]/[Chitmon] ≈ 0.16, which was attributed to the partial breakdown of interchain crosslinking and formation of discrete charged aggregates. After this point, reaction should occur by neutralization of these assemblies, causing new reduction in values of Dh, ZP and η until [TPP]/[Chitmon] ≈ 0.3, when they reached their lowest values. ITC experiment also showed the occurrence of two bindings (K1 = 3.6 × 103 and K2 = 7.7 × 104), which were entropy driven. Biological results showed lower C. albicans viability for TPP/Chit over 24 h compared with chitosan and nystatin at MIC and 2 MIC. Moreover, TPP/Chit showed 25-50% inhibition of C. albicans adhesion and biofilm formation. The results showed that TPP/Chit nanoparticles reduced the initial adhesion and biofilm formation of C. albicans and demonstrated potential for use in a formulation for the treatment of oral candidiasis.

Os medicamentos infantis podem causar erosão na superfície de dentes decíduos? Revisão sistemática da literatura / Can child medications cause erosion on the surface of deciduous teeth? A systematic review of literature

Introdução: A erosão dentária é caracterizada por uma perda progressiva e irreversível dos tecidos dentários mineralizados que ocorre sem envolvimento bacteriano. Acredita-se que o uso frequente de medicamentos líquidos orais, em crianças, possa desenvolver erosão dentária visto que esses medicamentos apresentam, em sua maioria, pH ácido, que pode atuar como fator predisponente ao desenvolvimento da erosão dentária. Objetivo: O presente estudo avaliou os efeitos do uso de medicamentos líquidos orais na estrutura de dentes decíduos por meio de revisão sistemática da literatura. Material e Métodos: Foi realizada pesquisa de artigos científicos, em março de 2018, nas bases de dados PubMed e Web of Science utilizando descritores específicos para a pesquisa, de modo a avaliar, descritivamente, a seguinte pergunta "Os medicamentos infantis de uso contínuo podem causar erosão na superfície de dentes decíduos?" Foram encontrados 278 artigos na base de dados Pubmed e 41 na base Web of Science, dos quais 18 artigos eram coincidentes, assim 301 títulos e resumos foram lidos e analisados. Destes, 293 foram excluídos de modo que 8 artigos foram selecionados para análise crítica. Resultados: Os medicamentos líquidos de uso contínuo, geralmente utilizados para o tratamento de condições crônicas em crianças, promovem efeito erosivo sobre a estrutura dentária, principalmente quando relacionado ao pH e acidez titulável dos medicamentos, por avaliação de estudos conduzidos "in vitro". Conclusão: Torna-se necessária a realização de estudos clínicos para avaliação mais adequada do efeito erosivo de medicamentos infantis na superfície de dentes decíduos.

Introduction: Dental erosion is characterized by a progressive and irreversible loss of mineralized dental tissues that occurs without bacterial involvement. It is believed that the frequent use of oral liquid medicines in children can develop dental erosion since the majority of these medications has acidic pH, which can act as a predisposing factor for dental erosion development. Objective: The present study evaluated the effects of the use of liquid oral medications on the structure of deciduous teeth by a systematic review of literature. Material and Methods: We conducted a survey of scientific articles in PubMed and Web of Science databases on March 2018, using specific descriptors for the research, in order to evaluate descriptively the following question: "Children's medicines for continuous use may cause erosion on the surface of deciduous teeth?". We found 278 articles in the PubMed database and 41 in the Web of Science database, of which 18 articles were matched, so 301 titles and abstracts were read and analyzed. Of these, 293 were excluded. Thus, 8 articles were selected for the critical analysis. Results: Liquid medications of continuous use, generally used for the treatment of chronic conditions in children, promoted erosive effect on dental structure, especially when related to pH and titratable acidity of the drugs in in vitro studies. Conclusion:It is necessary to carry out clinical studies for a more adequate evaluation of the erosive effect of children's medicines on the surface of deciduous teeth.

Effect of chitosan nanoparticles on the inhibition of Candida spp. biofilm on denture base surface.

OBJECTIVES: Chitosan nanoparticles (ChNPs) have antifungal effects, however there is a lack of information about the effects of ChNPs against Candida biofilm on denture base surface. This study investigated the ChNPs effect against C. albicans biofilm adhesion and formation, and against Candida spp. biofilm on heat-cured acrylic resin. DESIGN: The ChNPs were synthetized (3800 µg/mL) and characterized by infra-red spectrophotometry and transmission electron microscopy. The minimum inhibitory/fungicidal concentrations (MIC/MFC) against Candida spp. were determined. The time-kill assay and changes on C. albicans micromorphology were evaluated. The % inhibition of ChNPs on C. albicans biofilm formation and reduction were investigated using 1 min and 8 h exposure. Candida biofilm was developed on resin surfaces and ChNPs were applied every 8 h for 5 days. After, fungal cells were counted (CFU/mL) and the surface roughness (Ra) and vickers microhardness (HV) of resin were analysed. For all experiments, sodium hypochlorite (NaOCl) was used as control. Data were analyzed by ANOVA, Tukey and paired t-tests (α = 0.05). RESULTS: The MIC80% of ChNPs was 30.1 µg/mL. ChNPs at 4 MIC showed complete inhibition in the time-kill assays. Blastoconidia cells were predominant after ChNPs application. The % inhibition ChNPs on C. albicans was proportional to its concentration, regardless of the exposure time. ChNPs decreased the CFU/mL of Candida spp. and showed lower alteration of HV and Ra values of resin surface compared to NaOCl. CONCLUSIONS: The ChNPs inhibited C. albicans biofilm, reduced Candida biofilm on resin and caused small changes in roughness and hardness of acrylic resin surface.