Anticaries Agent Based on Silver Nanoparticles and Fluoride: Characterization and Biological and Remineralizing Effects-An In Vitro Study.

Objective: The aim of the study was to characterize and evaluate the stability, antimicrobial activity, cytotoxicity, and remineralizing effects of silver nanoparticles and fluoride anticaries agent (AgF) on staining dental enamel. Materials and Methods: An experimental AgF solution was prepared and compared to silver diamine fluoride (SDF). First, the AgF was characterized and the stability was evaluated by transmission electron microscopy (TEM). Streptococcus mutans, Enterococcus faecalis, and Escherichia coli strains were used to evaluate the minimum inhibitory and bactericidal concentration and cytotoxicity performed using L929 fibroblastic cells by MTT test. Caries-like lesions induced by pH-cycling in human enamel were obtained, and then, the superficial microhardness, cross-sectional microhardness (CSMH), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were performed. Photographic images were taken to analyze the enamel staining. Results: The AgF showed stableness in long term with bacteriostatic and bactericidal actions without cytotoxicity. Enamel remineralization, in surface and in depth (CSMH), was observed when the AgF was used, and it was similar to SDF. SEM showed enamel precipitation, and EDS observed the presence of P, Ca, Au, Ag, and Cl elements. Contrary to SDF, AgF did not stain the enamel. Conclusion: The nano silver fluoride anticaries agent tested presented long-term stability, superficial and in-depth remineralizing capacity with antimicrobial potential and biocompatibility and did not stain the enamel.

Effect of Chemical Challenges on the Properties of Composite Resins.

OBJECTIVE: To evaluate the chemical degradation effect on microhardness and roughness of composite resins after aging. MATERIALS AND METHODS: Specimens (n = 10) were used for Filtek Z350 XT (Z350), Filtek Bulk Fill (BULK), Micerium HRI (HRI), Micerium BIOFUNCION (BIO), and Vittra APS (VITTRA). Microhardness and roughness were performed before and after degradation with the followed solutions: citric acid, phosphoric acid, 75% alcohol, and distilled water. Samples were to a 180-day chemical cycling protocol. After degradation, one sample of each group was selected for scanning electron microscope evaluation. The data were analyzed with normal distribution (Kolmogorov-Smirnov) and similarities of variations for the Bartlett test. ANOVA (two-way) followed by Tukey's test was performed considering treatment and composite resin (P < 0.05). RESULTS: For microhardness and roughness, variations were noted to different solution and resin formulations. Z350 and HRI showed higher microhardness percentage loss, and it was more evident after storage in alcohol (-48.49 ± 20.16 and -25.02 ± 14.04, respectively) and citric acid (-65.05 ± 28.97 and 16.12 ± 8.35, respectively). For roughness, Z350 and VITTRA showed less delta values after alcohol storage (-0.047 ± 0.007 and -0.022 ± 0.009, respectively). HRI had the worst roughness for citric acid (-0.090 ± 0.025). All resins were not statistically different between each other in water and phosphoric acid. CONCLUSION: The formulations of restorative resin materials influenced in degree of surface degradation after 180 days of chemical degradation. Water was considered the solution that causes less degradation for microhardness and roughness evaluations. For microhardness, alcohol was considered the worst solution for Z350 and HRI. For superficial roughness, Z350 and VITTRA showed less degradation in alcohol and citric and phosphoric acid solutions.

Effect of application time and concentration of silver diamine fluoride on the enamel remineralization.

BACKGROUND: Silver diamine fluoride has attracted attention because of its clinical success in arresting dental caries. Thus, the aim of this study was to evaluate the effect of different application times and concentrations of silver diamine fluoride (SDF) on deciduous tooth enamel remineralization. MATERIAL AND METHODS: Blocks of deciduous tooth enamel were categorized into six groups of 11 each: 2 control groups: intact enamel, and demineralized enamel; 38% SDF and 30% SDF which were subdivided according to application times (1 and 3 min). The microhardness of samples was determined, and all groups except the intact enamel group were subjected to pH cycling to produce initial carious lesions. The 38% and 30% SDF solutions were applied to the enamel for 1 or 3 min. After pH cycling and SDF treatments, the microhardness was again determined. Samples were sectioned to evaluate the cross-sectional microhardness. Furthermore, internal porosity of the samples was examined using micro-CT. Data were statistically analyzed by analysis of variance followed by Tukey's test, and linear regression analyses were performed. RESULTS: There was no difference in enamel remineralization based on surface and cross-sectional microhardness. The 30% SDF solution applied for 3 min promoted significantly less pores than the other groups. CONCLUSIONS: The 1-min application time promoted enamel remineralization regardless of the SDF concentration (30% or 38%). Key words:Cariostatic agents, dental caries, primary tooth, tooth remineralization.

Can silver diamine fluoride or silver nanoparticle-based anticaries agents to affect enamel bond strength?

OBJECTIVES: The aim of the current study is to investigate the effect of different anticaries agents, such as experimental agents based on silver nanoparticles (SNPs) and silver diamine fluoride (SDF), on the micro-shear bond strength (µ-SBS) of composite resin applied to intact enamel (IE) or demineralized enamel (DE). MATERIALS AND METHODS: Sixty dental enamel fragments were collected from human third molars and categorized into 6 groups (n = 10): positive control (IE), negative control (DE), IE + SDF, DE + SDF, IE + SNP and DE + SNP. Samples from DE, DE + SDF and DE + SNP groups were subjected to pH cycling; superficial microhardness test was performed to confirm demineralization. Resin composite build-ups were applied to the samples (0.75-mm diameter and 1-mm height) after the treatments (except for IE and DE groups); µ-SBS was also evaluated. Samples were analyzed under a stereomicroscope at 40× magnification to identify failure patterns. Data were subjected to one-way analysis of variance, followed by Tukey's and Dunnett's tests (p < 0.05). RESULTS: There was no significant difference among the IE, IE + SNP, DE + SDF, and DE + SNP groups. The IE + SDF and DE groups recorded the highest and the lowest µ-SBS values, respectively. Adhesive-type failures were the most frequent for all treatments. CONCLUSIONS: Anticaries agents did not have a negative effect on the µ-SBS of composite resin when it was used on IE or DE.

Evaluation of the effects of whitening mouth rinses combined with conventional tooth bleaching treatments.

OBJECTIVES: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. MATERIALS AND METHODS: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. RESULTS: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. CONCLUSIONS: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.

Treatment of Dental Caries with Diamine Silver Fluoride: Literature Review / Tratamento da Cárie Dentária com Diamino Fluoreto de Prata: Revisão da Literatura

Brazilian health care programs recommend the use of cariostatic solutions of silver diamine fluoride (SDF) or sodium fluoride varnishes for children 0 to 3 years old with high or moderate caries activity for the control of caries lesions. SDF is a safe, economical, efficient and non-invasive coadjuvant agent, exerting an antibacterial action capable of reducing superficial mineral loss of the enamel and can be used in the treatment of deciduous and permanent teeth. The objective of this literature review was to gather current information on describing the mechanism of SDF action' and its clinical application in young children in caries prevention and paralysis. The PubMed / Medline and Cochrane Library databases were accessed by identifying the relevant studies published in English from 1960 to May 2017. The search strategy employed the keywords: "Silver diamine fluoride" and "Children "or "Infant" and "Caries prevention". Data extraction was performed in: 19 in vitro studies; 10 review articles and 8 in vivo studies. It was possible to conclude that SDF is almost twice as effective compared to fluoride varnish in caries paralysis. However, the contact time of the solution and the optimal frequency of application of the SDF are still undefined, inducing new projects and clinical studies in the search for an adequate clinical protocol of this cariostatic.(AU)

Os programas de assistência à saúde brasileiros recomendam para o controle das lesões de cárie a utilização de soluções cariostáticas de diamino fluoreto de prata - DFP ou vernizes de fluoreto de sódio para crianças de 0 a 3 anos com atividade de cárie alta ou moderada. O DFP é agente coadjuvante seguro, econômico, eficiente e não invasivo, exercendo ação antibacteriana capaz de reduzir a perda mineral superficial do esmalte e, pode ser utilizado no tratamento de dentes decíduos e permanentes. O objetivo desta revisão de literatura foi reunir informações atuais sobre descrever o mecanismo de ação do DFP e sua aplicação clínica em crianças de pouca idade na prevenção e paralisação da cárie. As bases de dados PubMed/Medline e Cochane Library foram acessadas identificando os estudos relevantes publicados em inglês, no período de 1960 a maio de 2017. A estratégia de busca empregou as palavras-chave: "Silver diamine fluoride" and "Children" or "Infant" and "Caries prevention". A extração dos dados foi realizada em: 19 estudos in vitro; 10 artigos de revisão e 8 estudos in vivo. Foi possível concluir que o DFP apresenta-se quase duas vezes tão eficaz comparado ao verniz fluoretado na paralização de cárie. Porém, o tempo de contato da solução e a frequência ótima de aplicação do DFP ainda estão indefinidos, suscitando novos projetos e estudos clínicos na busca de adequado protocolo clínico deste cariostático.(AU).

Uso e Necessidade de Prótese Dentária em Idosos de Londrina, Paraná / Use and need of Dental Prosthesis in the Elderly in Londrina, Paraná

Este estudo avaliou a necessidade e uso de prótese entre 504 idosos independentes, cadastrados nas Unidades Básicas de Saúde (UBS) do município de Londrina, Paraná. As características sociodemográficas foram também analisadas. A situação quanto às próteses dentárias foi avaliada a partir de informações sobre seu uso e necessidade nos arcos superior e inferior. As observações ao exame levaram em conta os códigos e critérios preconizados pela Organização Mundial de Saúde (OMS). As informações sociodemográficas foram obtidas pela aplicação de um formulário estruturado, avaliando: sexo, idade, nível de escolaridade, estado conjugal, tipo de moradia, número de pessoas na casa, renda familiar. A idade dos 504 idosos avaliados envolveu entre 60 e 75 anos, sendo a maioria entre 65 e 74 anos (54,2%), do gênero feminino (66,3%), de procedência rural (53,8%), cor branca (62,1%) e com até 4 anos de estudo (80,6%). Destes idosos, 15,1% não usam qualquer tipo de prótese, 24,6% usam em uma arcada e 60,3% usam algum tipo de prótese nas duas arcadas. Quanto à necessidade de prótese, observou-se que 21,6% não necessitam de qualquer tipo de prótese, 19,4% necessitam em uma arcada e a maioria (58,9%) necessita nas duas arcadas. Somente houve dependência, estatisticamente significante, entre as variáveis de necessidade de prótese dentária e gênero, cor da pele e procedência. Sendo assim, pode-se concluir que a prevalência de necessidade de prótese é acentuada e existe uma demanda populacional para reabilitação protética. (AU)

This study evaluated the need and use of prosthesis among 504 independent elderly, registered in the Basic Health Units (BHU) of the city of Londrina, Paraná. Sociodemographic characteristics were also evaluated. The situation regarding dental prosthesis was evaluated based on information about their use and need in the upper and lower arches. The observations were performed according to the codes and criteria recommended by the World Health Organization (WHO). The sociodemographic information was obtained by applying a structured form, evaluating: gender, age, educational level, marital status, housing type, number of people living in the residence, family income. The age of the 504-elderly studied was between 65 and 74 years (54.2%), female (66.3%), rural origin (53.8%), white skin color (62.1%) and up to 4 years of schooling (80.6%). Of these elderly, 15.1% do not use any type of prosthesis, 24.6% use only in one dental arch and 60.3% use some type of prosthesis in both arches. Regarding the need of prosthesis, it was observed that 21.6% do not require any type of prosthesis, 19.4% need in one arch and the majority (58.9%) needs in both arches. There was only statistically significant dependence among the variables of need for dental prosthesis and gender, skin color and origin. Thus, it can be concluded that the prevalence of need for prosthetic is high and there is a population demand for prosthetic rehabilitation. (AU)