ABSTRACT Objective: To assess the in-vitro effect of single applications of CPP-ACP pastes and different fluoridated solutions on the prevention of dental caries around orthodontic brackets. Material and Methods: Tooth/bracket sets (n=65) were immersed in artificial saliva (1h at 37ºC) and randomly subjected to single applications (100µL; 1min) of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP emulsion), CPP-ACP with fluoride (CPP-ACPF emulsion), solutions of titanium tetrafluoride (TiF4) or sodium fluoride (NaF), or no treatment (CG). Multispecies biofilm (5 x 105 CFU/mL) was formed in the presence of 2% sucrose. After 24 h, the pH and the concentration of total soluble fluoride (TSF) were analyzed by culture medium. The presence of active white spot lesions (WSL) evaluated by macroscopic examination and the percent surface mineral loss (%SML) were analyzed. Also, the topography of enamel was detected by analysis of scanning electron microscopy (SEM). The data was assessed by chi-square, Kruskal-Wallis, and Mann-Whitney tests (p < 0.05). Results: Fluoride-containing compounds led to a smaller pH reduction than did CPP-ACP and CG (p<0.05). There was difference in TSF between the groups (p<0.05), denoted as TiF4> NaF > CPP-ACPF > CPP-ACP > CG. Regarding the presence of WSL and %SML, the NaF group obtained lower values (p<0.05), while TiF4 and CPP-ACPF were similar (p>0.05). SEM demonstrated that fluoride-free groups had a larger surface dissolution. Conclusion: Fluoridated groups including solutions and CPP-ACPF were more effective than CPP-ACP in reducing enamel demineralization around orthodontic brackets after a single application.

RESUMO Objetivo: Avaliar in-vitro o efeito de uma aplicação única de cremes dentais de CPP-ACP e diferentes soluções fluoretadas na prevenção da cárie dentária ao redor de braquetes ortodônticos Material e Métodos: O conjunto dentes/braquetes (n=65) foi imerso em saliva artificial (1h em 37°C) randomizado e submetido a tratamento único (100µL; 1 min) de emulsão de fosfopeptídeo de caseína-fosfato de cálcio amorfo (CPP-ACP) e CPP-ACP associado ao flúor (CPP-ACPF); soluções de tetrafluoreto de titânio (TiF4) e fluoreto de sódio (NaF); e ausência de tratamento (GC). Biofilmes multiespécie (5 x 105 CFU/mL) foram formados na presença de sacarose a 2%. Após 24h, o pH e a concentração de fluoreto solúvel total (FST) foram analisados pelo meio de cultura. Foram avaliadas a presença de lesões de mancha branca (LMB), por meio da análise de macroscopia visual, e a porcentagem de perda de dureza (%PD). Também foi verificada a topografia do esmalte, usando microscopia eletrônica de varredura (MEV). Os dados foram analisados pelos testes Qui-quadrado, Kruskal-Wallis e Mann-Whitney (p < 0,05). Resultados: Os compostos contendo flúor levaram a uma redução do pH menor do que o CPP-ACP e GC (p<0,05). Houve diferença no FST entre os grupos (p <0,05), sendo TiF4> NaF > CPP-ACPF > CPP-ACP > GC. Quanto à presença de LMB e à %PD, o grupo NaF obteve os menores valores (p<0,05), enquanto TiF4 e CPP-ACPF foram semelhantes (p> 0,05). A MEV demonstrou que os grupos sem flúor tiveram uma dissolução superficial maior. Conclusão: Os grupos fluoretados, incluindo soluções e CPP-ACPF, foram mais eficazes do que o CPP-ACP sem flúor na redução da desmineralização do esmalte ao redor dos braquetes ortodônticos após uma única aplicação.

Abstract Objective: To describe the impact of the COVID-19 pandemic on dental care provided to pediatric cancer patients assisted in a referral hospital. Material and Methods: This is an observational, retrospective study based on secondary data extracted from worksheets of dental procedures for patients aged between 0 and 19 years assisted in the pediatric oncology sector of a hospital in João Pessoa, PB, Brazil. Dental procedures performed by the interdisciplinary team of researchers from August 2018 to February 2020 (19 months prior to the pandemic) and from April 2020 to October 2021 (19 months during the pandemic) were totaled and compared. A descriptive analysis of the data was performed. Results: There was a reduction of 80.2% in dental interventions implemented in the sector during the pandemic, with the number of procedures decreasing from 6,210 (the period before the pandemic) to 1,229 (during the pandemic). Most procedures in both periods were performed for patients assisted in beds, for whom there was a reduction of care provided for 81.2% from 5,275 to 994 procedures. Dental procedures in the outpatient clinic decreased by 74.9%, from 935 to 235. Conclusion: The COVID-19 pandemic negatively impacted dental care provided to pediatric oncology patients by restricting dental procedures to emergency demands, compromising performance prevention and health promotion actions.

RESUMO Este estudo teve como objetivo avaliar o efeito in vitro de uma única aplicação de soluções experimentais de nanocompósitos na prevenção de cárie dentária em braquetes ortodônticos. Os espécimes foram expostos a nanocompósitos de sílica mesoporosa (MS) contendo fluoreto por associação com tetrafluoreto de titânio (TiF4) ou fluoreto de sódio (NaF). Os nanocompósitos também podem conter cálcio e os grupos foram descritos como MSCaTiF4, MSTiF4, MSCaNaF, MSNaF e controles (TiF4 e NaF). Os espécimes foram submetidos à formação de um biofilme multiespécie para gerar um desafio cariogênico. Após 24h, o pH e a concentração de flúor solúvel total do meio de cultura foram avaliados. A perda mineral foi avaliada pela porcentagem de perda mineral superficial (% SML), variação do volume mineral (ΔZ) do esmalte interno e microscopia de luz polarizada (PL). A rugosidade superficial linear (Ra) e volumétrica (Sa) e a microscopia eletrônica de varredura (MEV) foram utilizadas para avaliar a topografia do esmalte. As análises estatísticas foram realizadas considerando p <0,05. MSNaF apresentou o maior valor de pH do meio de cultura após o desafio cariogênico, semelhante ao MSTiF4. Todas as soluções de nanocompósitos liberaram menos flúor do que seus controles NaF e TiF4 (p <0,05). Todas as soluções de nanocompósitos apresentaram% SML menor em comparação com seus respectivos grupos de controle (p <0,05). Ra, Sa e ΔZ menores foram observados para os grupos experimentais em comparação ao TiF4 (p <0,05). Os resultados foram confirmados por análises PL e SEM. As soluções experimentais de nanocompósitos contribuíram para a menor desmineralização do esmalte ao redor dos braquetes ortodônticos.

Abstract This study aimed to evaluate the in vitro effect of a single application of experimental nanocomposite solutions on the prevention of dental caries around orthodontic brackets. The specimens were exposed to mesoporous silica (MS) nanocomposites containing fluoride by association with titanium tetrafluoride (TiF4) or sodium fluoride (NaF). Nanocomposites also could contain calcium and groups were described as MSCaTiF4, MSTiF4, MSCaNaF, MSNaF, and controls (TiF4, and NaF). Specimens were subjected to the formation of a multispecies biofilm to generate a cariogenic challenge. After 24h, both pH and total soluble fluoride concentration of the culture medium were assessed. Mineral loss was evaluated by percentage of surface mineral loss (%SML), mineral volume variation (ΔZ) of inner enamel and polarized light microscopy (PL). Linear (Ra) and volumetric (Sa) surface roughness and scanning electronic microscopy (SEM) were used to assess enamel topography. Statistical analyses were conducted considering p<0.05. MSNaF had the highest value of culture medium pH after cariogenic challenge, similarly to MSTiF4. All nanocomposite solutions released less fluoride than their controls NaF and TiF4 (p<0.05). All nanocomposite solutions presented lower %SML compared to their respective control groups (p<0.05). Lower Ra, Sa and ΔZ were observed for experimental groups compared to TiF4 (p<0.05). The results were confirmed by PL and SEM analysis. The experimental nanocomposite solutions contributed for lower enamel demineralization around orthodontic brackets.

Resumo O objetivo deste estudo foi comparar os efeitos de uma única aplicação de uma nova nanopartícula de sílica mesoporosa de cálcio (Ca2+ -MSN) versus outros produtos à base de cálcio e / ou fluoreto contra a erosão dentária. Blocos de esmalte foram parcialmente cobertos e distribuídos em seis grupos (n = 10): Ca2+ -MSNs; fosfopeptídeos de caseína/fosfato de cálcio amorfo (CPP-ACP); CPP-ACP / F- (900 ppm F-); tetrafluoreto de titânio (TiF4 1%); fluoreto de sódio (NaF 1,36%); e água Milli-Q® (controle negativo). Uma única aplicação para cada produto foi realizada nas áreas expostas dos blocos e submetida a desafio erosivo. Diferenças na rugosidade volumétrica (Sa) e na perda de estrutura dentária (TSL) por meio de perfilometria tridimensional de não contato foram avaliadas. Microscopia eletrônica de varredura (MEV) foi realizada. Foram realizadas análise de variância e teste de Tukey para os testes Sa e Kruskal-Wallis e Mann-Whitney (p<0,05) para TSL, respectivamente. Na avaliação de Sa, todos os produtos apresentaram diferenças de rugosidade quando comparados ao grupo controle (p<0,05), mas não entre si (p> 0,05). No entanto, ao analisar o TSL, observou-se que Ca2+ -MSNs, TiF4 e NaF foram mais eficazes na prevenção da erosão dental versus CPP-ACP, CPP-ACP / F- e Milli-Q® (p<0,05). Nas imagens de MEV, o controle negativo apresentou a pior perda de estrutura dentária, com o esmalte mais poroso. A Ca2+ -MSNs foi tão eficaz quanto o TiF4 e o NaF para reduzir a perda da estrutura dentária.

Abstract The aim of this study was to compare the effects of a single application of a new calcium mesoporous silica nanoparticle (Ca2+-MSN) versus other calcium and/or fluoride products against dental erosion. Enamel blocks were half-covered and assigned to six groups (n = 10): Ca2+-MSNs; casein phosphopeptide-amorphous calcium phosphate mousse (CPP-ACP); CPP-ACP/F− (900 ppm F−); titanium tetrafluoride (TiF4 1%); sodium fluoride (NaF 1.36%); and Milli-Q® water (negative control). A single application for each product was completed on the exposed areas of the blocks and were submitted to an erosive challenge. Differences in volumetric roughness (Sa), and tooth structure loss (TSL) by use of three-dimensional noncontact optical profilometry were evaluate. Scanning electron microscopy (SEM) was performed. Analysis of variance and Tukey’s test for Sa and the Kruskal-Wallis and Mann-Whitney U tests (p< 0.05) for TSL, respectively. Results: When evaluating Sa, all products presented differences in roughness when compared with the control group (p< 0.05) but not with each other (p > 0.05). However, when analyzing the TSL, it was observed that Ca2+-MSNs, TiF4, and NaF were more effective in preventing dental erosion versus CPP-ACP, CPP-ACP/F−, and Milli-Q® water (p< 0.05). In the SEM images, the negative control presented the worst loss of dental structure, with more porous enamel. Ca2+-MSNs were as effective as TiF4 and NaF to reduce the tooth structure loss.

Abstract Objective: To evaluate the effect of a calcium nanocompound on the reduction of erosive tooth wear and abrasion. Material and Methods: Bovine enamel specimens (BE), were randomly assigned to the following groups (n = 10): G1 = Calcium mesoporous silica nanoparticles (Ca2+MSNs); G2 = casein phosphopeptide-amorphous calcium phosphate (CPP-ACP, 2% CPP-ACP, GC®); G3 = casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP, 2% CPP-ACP + 900 ppm F-, GC®); G4 = sodium fluoride NaF (900 ppm F-, positive control); and G5 = distilled and deionized water (negative control). Each product was applied to the exposed area for one minute, three times per day for three consecutive days, and followed by the immersion of the specimens in Sprite Zero™ - a low-pH solution (2.58) for five minutes (Coca-Cola™). After the first and last erosive challenges of the day, the specimens were submitted to abrasion in a toothbrush machine for 15 seconds (200 g/BE). The specimens were analysed using 3D non-contact optical profilometry, with tooth structure loss (TSL) measurements and scanning electron microscopy (SEM). TSL values were analysed by Kruskal-Wallis and Mann-Whitney tests (p<0.05). Results: There were no significant differences between G1 (10.95 µm) and G3 (10.80 µm) treatments for TSL values; however both resulted in significantly reduced TSL values compared with the G5 (16.00 µm) (p<0.05). The G4 (12.26 µm) showed no statistically significant difference when compared to the G5 (16.00 µm). The groups G1 and G3 presented higher surface preservation than the G5. Conclusion: Ca2+MSNs was effective for reducing tooth surface loss caused by erosive tooth wear and abrasion.

Abstract Objective: To evaluate in vitro the effect of a red propolis ethanolic extract (RPE) in the prevention of growth of a cariogenic biofilm and its cytotoxic potential. Material and Methods: Minimum inhibitory and bactericidal concentrations (MIC and MBC) of RPE against Streptococcus mutans and Lactobacillus casei were determined. The cytotoxic potential of 0.4% RPE in oral fibroblasts was observed after 1, 3 and 5 min of contact. Cellulose membrane disks (13 mm, N=12) were used for biofilm formation (24 h) of S. mutans and L. casei, which were treated (1 min) with 0.4% RPE or 0.12% Chlorhexidine (CHX). The control group of biofilm formation was not submitted to any treatment. Serial dilutions were then made to evaluate microbial viability. Descriptive data analysis and, for microbial viability, Mann Whitney test were performed (p≤0.05). Results: RPE showed similar MIC and MBC (4.46 mg/mL) against S. mutans and, for L. casei, they were 8.92 mg/mL (MIC) and 17.85 mg/mL (MBC). CHX presented MIC and MBC <0.00002 mg/mL for S. mutans and 0.00047 mg/mL for L. casei. After 1, 3 and 5 min, the RPE exhibited, respectively, 69.38%, 43.91% and 40.36% of viable cells. The RPE (6.55) and CHX (6.87) presented similar efficacy to reduce the total number of viable bacteria (p>0.05). Regarding the total number of viable bacteria (Log10 CFU/mL), the RPE (6.55) and CHX (6.87) presented similar efficacy (p>0.05). Conclusion: Red propolis extract showed antibacterial activity against the tested strains, exhibited acceptable cytotoxicity and reduced the colonization of S. mutans and L. casei in a biofilm membrane model.

Abstract The aim of this study was to check the in vitro accuracy of ICDAS criteria on digital images compared to visual examination for the diagnosis of occlusal caries against a micro-CT gold standard. ICDAS was scored in 40 extracted permanent molars by means of visual inspection and stereomicroscopic images. Visual examinations were performed in duplicate and at a one-week interval by three different calibrated examiners. The analysis of digital images by ICDAS criteria was also performed in duplicate, 1 month after visual examinations. The detection methods were compared by means of sensitivity, specificity, area under the curve, predictive positive and negative values, and accuracy for two different thresholds (1- sound vs. carious teeth; 2- tooth requiring operative vs. non-operative treatment). Sensitivity and accuracy values for threshold 1 in the visual ICDAS and image-based ICDAS methods were high for sensitivity (0.93 and 0.97) and for accuracy (0.83 and 0.85), but low for specificity (0.55 for both methods). Specificity values for threshold 2 were 0.77 and 0.82, while sensitivity was 0.33 and 0.28 for each method. Spearman’s rank correlation coefficient was 0.53 and 0.43 (p<0.05) for visual and image-based ICDAS compared to the gold standard scores. Both visual and image-based ICDAS scores were similar to each other in terms of diagnostic accuracy when compared to the micro-CT gold standard. Low specificity for the presence of caries and sensitivity for the detection of caries requiring operative treatment were found.