Influence of coating dental enamel with a TiF4-loaded polymeric primer on the adverse effects caused by a bleaching gel with 35% H2O2.

OBJECTIVE: To evaluate whether coating enamel with a polymeric primer (PPol) containing titanium tetrafluoride (TiF4) before applying a bleaching gel with 35% H2O2 (35% BG) increases esthetic efficacy, prevents changes in morphology and hardness of enamel, as well as reduces the cytotoxicity from conventional in-office bleaching. MATERIALS AND METHODS: Standardized enamel/dentin discs were stained and bleached for 45 min (one session) with 35% BG. Groups 2TiF4, 6TiF4, and 10TiF4 received the gel on the enamel previously coated with PPol containing 2 mg/mL, 6 mg/mL, or 10 mg/mL, respectively. No treatment or application of 35% BG directly on enamel were used as negative control (NC), and positive control (PC), respectively. UV-reflectance spectrophotometry (CIE L*a*b* system, ΔE00, and ΔWI, n = 8) determined the bleaching efficacy of treatments. Enamel microhardness (Knoop, n = 8), morphology, and composition (SEM/EDS, n = 4) were also evaluated. Enamel/dentin discs adapted to artificial pulp chambers (n = 8) were used for trans-amelodentinal cytotoxicity tests. Following the treatments, the extracts (culture medium + bleaching gel components diffused through the discs) were collected and applied to odontoblast-like MDPC-23 cells, which were assessed concerning their viability (alamarBlue, n = 8; Live/Dead, n = 4), oxidative stress (n = 8), and morphology (SEM). The amount of H2O2 in the extracts was also determined (leuco crystal violet/peroxidase, n = 8). The numerical data underwent one-criterion variance analysis (one-way ANOVA), followed by Tukey's test, at a 5% significance level. RESULTS: Regarding the ΔE00, no difference was observed among groups 2TiF4, 6TiF4, and PC (p > 0.05). The ΔWI was similar between groups 2TiF4 and PC (p > 0.05). The ΔWI of group 6TiF4 was superior to PC (p < 0.05), and group 10TiF4 achieved the highest ΔE00 and ΔWI values (p < 0.05). Besides limiting enamel microstructural changes compared to PC, group 10TiF4 significantly increased the hardness of this mineralized dental tissue. The highest cellular viability occurred in 10TiF4 compared to the other bleached groups (p < 0.05). Trans-amelodentinal H2O2 diffusion decreased in groups 2TiF4, 6TiF4, and 10TiF4 in comparison with PC (p < 0.05). CONCLUSION: Coating enamel with a PPol containing TiF4 before applying a 35% BG may increase enamel microhardness and esthetic efficacy and reduce the trans-amelodentinal cytotoxicity of conventional in-office tooth bleaching. The PPol containing 10 mg/mL of TiF4 promoted the best outcomes.

Pulp cell response to the application of silver diamine fluoride and potassium iodide on caries-like demineralized dentin.

OBJECTIVES: To investigate the response of pulp cells to the application of silver diamine fluoride (SDF) and potassium iodide (KI) on demineralized dentin. MATERIALS AND METHODS: The occlusal surfaces of human dentin discs (0.4 mm thick) with similar permeability were subjected to an artificial caries protocol, and then the discs were adapted into artificial pulp chambers. MDPC-23 cells were seeded on the healthy pulp dentin surface, while the demineralized surface was treated with SDF, KI, SDF + KI, or hydrogen peroxide (positive control-PC) (n = 8). The negative control (NC) received ultrapure water. After 24 h, cell viability (alamarBlue) and morphology (SEM) were evaluated. The extracts were then applied to new MDPC-23 cells seeded in culture plates to assess their viability and the formation of mineralized nodules (MN; Alizarin Red) after seven days. The data were analyzed using one-way analysis of variance/Tukey or Games-Howell tests (α = 5%). RESULTS: SDF and PC significantly reduced the viability of cells seeded on discs (45.6% and 71.0%, respectively). Only cells treated with SDF or PC detached from the dentin substrate, while the remaining cells showed altered morphology. Cells in contact with extracts showed less reduction in viability, but it was still more toxic compared to NC. Only PC reduced MN deposition. SDF + KI or KI alone did not affect the cell response. CONCLUSIONS: SDF applied alone showed a mild to moderate transdentinal cytotoxic effect on pulp cells. However, the combination of SDF + KI reduced the cytotoxic effects. Both materials used alone or in combination did not affect the mineralization ability of pulp cells. CLINICAL RELEVANCE: Besides improving esthetic results, associating potassium iodide with silver diamine fluoride may reduce the transdentinal cytotoxic effects of this cariostatic agent on pulp cells.

Chronic exposure to lipopolysaccharides as an in vitro model to simulate the impaired odontogenic potential of dental pulp cells under pulpitis conditions.

BACKGROUND: Simulating a bacterial-induced pulpitis environment in vitro may contribute to exploring mechanisms and bioactive molecules to counteract these adverse effects. OBJECTIVE: To investigate the chronic exposure of human dental pulp cells (HDPCs) to lipopolysaccharides (LPS) aiming to establish a cell culture protocol to simulate the impaired odontogenic potential under pulpitis conditions. METHODOLOGY: HDPCs were isolated from four healthy molars of different donors and seeded in culture plates in a growth medium. After 24 h, the medium was changed to an odontogenic differentiation medium (DM) supplemented or not with E. coli LPS (0 - control, 0.1, 1, or 10 µg/mL) (n=8). The medium was renewed every two days for up to seven days, then replaced with LPS-free DM for up to 21 days. The activation of NF-κB and F-actin expression were assessed (immunofluorescence) after one and seven days. On day 7, cells were evaluated for both the gene expression (RT-qPCR) of odontogenic markers (COL1A1, ALPL, DSPP, and DMP1) and cytokines (TNF, IL1B, IL8, and IL6) and the production of reactive nitrogen (Griess) and oxygen species (Carboxy-H2DCFDA). Cell viability (alamarBlue) was evaluated weekly, and mineralization was assessed (Alizarin Red) at 14 and 21 days. Data were analyzed with ANOVA and post-hoc tests (α=5%). RESULTS: After one and seven days of exposure to LPS, NF-κB was activated in a dose-dependent fashion. LPS at 1 and 10 µg/mL concentrations down-regulated the gene expression of odontogenic markers and up-regulated cytokines. LPS at 10 µg/mL increased both the production of reactive nitrogen and oxygen species. LPS decreased cell viability seven days after the end of exposure. LPS at 1 and 10 µg/mL decreased hDPCs mineralization in a dose-dependent fashion. CONCLUSION: The exposure to 10 µg/mL LPS for seven days creates an inflammatory environment that is able to impair by more than half the odontogenic potential of HDPCs in vitro, simulating a pulpitis-like condition.

Chronic exposure to lipopolysaccharides as an in vitro model to simulate the impaired odontogenic potential of dental pulp cells under pulpitis conditions

Abstract Simulating a bacterial-induced pulpitis environment in vitro may contribute to exploring mechanisms and bioactive molecules to counteract these adverse effects. Objective To investigate the chronic exposure of human dental pulp cells (HDPCs) to lipopolysaccharides (LPS) aiming to establish a cell culture protocol to simulate the impaired odontogenic potential under pulpitis conditions. Methodology HDPCs were isolated from four healthy molars of different donors and seeded in culture plates in a growth medium. After 24 h, the medium was changed to an odontogenic differentiation medium (DM) supplemented or not with E. coli LPS (0 - control, 0.1, 1, or 10 µg/mL) (n=8). The medium was renewed every two days for up to seven days, then replaced with LPS-free DM for up to 21 days. The activation of NF-κB and F-actin expression were assessed (immunofluorescence) after one and seven days. On day 7, cells were evaluated for both the gene expression (RT-qPCR) of odontogenic markers (COL1A1, ALPL, DSPP, and DMP1) and cytokines (TNF, IL1B, IL8, and IL6) and the production of reactive nitrogen (Griess) and oxygen species (Carboxy-H2DCFDA). Cell viability (alamarBlue) was evaluated weekly, and mineralization was assessed (Alizarin Red) at 14 and 21 days. Data were analyzed with ANOVA and post-hoc tests (α=5%). Results After one and seven days of exposure to LPS, NF-κB was activated in a dose-dependent fashion. LPS at 1 and 10 µg/mL concentrations down-regulated the gene expression of odontogenic markers and up-regulated cytokines. LPS at 10 µg/mL increased both the production of reactive nitrogen and oxygen species. LPS decreased cell viability seven days after the end of exposure. LPS at 1 and 10 µg/mL decreased hDPCs mineralization in a dose-dependent fashion. Conclusion The exposure to 10 µg/mL LPS for seven days creates an inflammatory environment that is able to impair by more than half the odontogenic potential of HDPCs in vitro, simulating a pulpitis-like condition.

The influence of violet LED application time on the esthetic efficacy and cytotoxicity of a 35% H2O2 bleaching gel.

OBJECTIVE: To assess the potential influence of violet LED (V-LED) application time on the esthetic efficacy and cytotoxicity of a 35% H2O2 bleaching gel. METHODOLOGY: Stained and standardized enamel/dentin discs were subjected to one in-office tooth bleaching session (45 min), and the gel was either irradiated or not with V-LED. Thus, the following groups were established (n = 8): G1: No treatment (negative control, NC); G2: 35% H2O2 (positive control, PC); G3: 35%H2O2 + V-LED/15 min; G4: 35%H2O2 + V-LED/30 min; G5: 35%H2O2 + V-LED/45 min. First, esthetic efficacy was assessed (ΔE00 and ΔWI). Discs assembled in artificial pulp chambers were subjected to the same bleaching treatments. Then, the extracts (culture medium + diffused bleaching gel components) were collected and applied to MDPC-23 pulp cells, which were analyzed for viability (Live/Dead, MTT) and oxidative stress (OxS). The amount of H2O2 in the extracts was also determined (leuco crystal-violet/peroxidase). The data were subjected to ANOVA/Tukey at a 5% significance level. RESULTS: Although esthetic efficacy did not differ among the irradiated groups (G3, G4, and G5) (p > 0.05), their results were higher than in G2 (PC; p < 0.05). In the irradiated groups, the cell viability and OxS as well as the amount of H2O2 in the extracts were statistically similar to G2 (PC), regardless of irradiation time (p > 0.05). CONCLUSION: Although V-LED improves the esthetic outcome of in-office tooth bleaching, increasing irradiation time does not effect the color changes and cytotoxicity of this professional therapy.

Nano-hydroxyapatite-incorporated polycaprolactone nanofibrous scaffold as a dentin tissue engineering-based strategy for vital pulp therapy.

OBJECTIVES: Targeting a tissue engineering-based vital pulp therapy (VPT), this study investigated the incorporation of nano-hydroxyapatite (nHA) into polycaprolactone (PCL) nanofibers, and the metabolism of human dental pulp cells (HDPCs) seeded on the scaffolds. METHODS: PCL-based solutions (10% w/v) containing nHA (0 - control; 0.5; 1.0; or 2.0% w/v) were electrospun into nanofibrous scaffolds. The scaffolds were characterized for morphology and composition (MEV/EDS), solubility, the release of calcium/phosphate (C/P), and modulation of medium pH. Then, HDPCs were seeded on the scaffolds and evaluated for cell viability (alamarBlue and live/dead), adhesion and spreading (F-actin), total protein (TP; Lowry), alkaline phosphatase activity (ALP; thymolphthalein assay), expression of odontogenic genes (RT-qPCR), and formation of a mineralized matrix (Alizarin Red). Data were analyzed with ANOVA and post-hocs (α = 5%). RESULTS: Higher nHA concentrations roughened fiber surfaces, whereas PCL+ 2%nHA increased the interfibrillar spaces. PCL+ 1%nHA or PCL+ 2%nHA significantly released more C/P but the medium pH was maintained below 8.0. HDPCs viability was not affected by nHA, while cell adhesion/spreading was favored, especially for PCL+ 2%nHA. Higher protein content and ALP activity were seen for scaffolds incorporated with nHA, after 21 days. PCL+ 1%nHA and PCL+ 2%nHA upregulated the expression of DSPP and DMP1 in 14 days, and COL1A1, ALPL, and DMP1 in 21 days. The formation of a mineralized matrix was nHA concentration-dependent, and it was about 9 × higher for PCL+ 2%nHA. SIGNIFICANCE: nHA-incorporated PCL nanofibrous scaffolds are cytocompatible and can stimulate the adhesion and odontogenic potential of HDPCs. PCL+ 2%nHA formulation is a bioactive tissue engineering-based cell-homing strategy for VPT.

Do Dentistry and physical education students know the importance of mouthguard usage in sports practice? / Os alunos da Odontologia e Educação Física conhecem a importância do uso de protetores bucais na prática desportiva?

ABSTRACT Objective The purpose of the present study was to evaluate the knowledge of Dentistry and Physical Education students on mouthguard usage in sports practice. Methods A form containing questions that demonstrated participants' knowledge about the use of mouthguards was applied. Inclusion criteria were: individuals older than 18 years who were attending Dentistry or Physical Education courses from the sixth period and who agreed to participate in the study, and the exclusion criteria for dentistry students were: attended the discipline of Dental Materials II of UFPE and already participated in internships in schools or academies for the participants of the Physical Education course. Results it was possible to observe that 97% of the interviewees know what a mouthguard is, but none of the participants would be able to indicate a specific type of mouthguard to sportsmen. Conclusion It was possible to conclude that a large number of the interviewees know what a mouthguard is, but not enough to indicate which is the safest protector.

RESUMO Objetivo Avaliar o conhecimento dos alunos do curso de Odontologia e Educação Física sobre os protetores bucais nos desportos. Métodos Aplicação de formulário avaliando conhecimento dos participantes sobre o uso de protetores bucais. Os critérios de inclusão foram: indivíduos maiores de 18 anos que estivessem cursando os cursos de Odontologia ou Educação Física a partir do sexto período e que concordassem em participar da pesquisa, já os critérios de exclusão para os alunos do curso de Odontologia foram: não ter cursado a disciplina de Materiais Dentários II da UFPE e já ter participado de estágios em escolas ou academias no caso dos participantes do curso de Educação Física. Resultados: foi possível observar que 97% dos entrevistados sabem o que é um protetor bucal, porém, nenhum dos participantes saberiam indicar um tipo específico de protetor bucal aos desportistas. Conclusão que uma grande parcela dos entrevistados conhece o que é um protetor bucal, porém, não o suficiente para poder indicar qual o protetor mais seguro.

Avaliação através da tomografia por coerência óptica do esmalte dentário após o uso de dentifrícios clareadores / Evaluation through tomography by optical coherence of dental enamel after the use of clearing dentifrices

Resumo Introdução Historicamente, materiais abrasivos, como mármore em pó, corais e cinzas ósseas, eram utilizados para higienização dentária. Com a evolução, tais materiais foram substituídos por dentifrícios aplicados em escovas dentais, com a mesma finalidade. Objetivo Avaliar, através da Tomografia por Coerência Óptica, o desgaste do esmalte dentário, após o uso de diferentes escovas dentais e materiais utilizados na escovação com componentes abrasivos. Material e método Foram confeccionados 50 corpos de prova, distribuídos em 10 grupos (n=5), de acordo com o dentifrício/escova utilizado. Para o grupo A, foi utilizada a escova dental Curaprox® Adulto Ultra Macia, e, para o grupo B, a escova Dental K® - escova adulto macia. Foram utilizados os seguintes materiais para escovação: Curaprox® Black is White; Colgate® Luminous White Instant, Close Up® White Attraction - MenSuperpure; Carvão Ativado; Água Destilada. As imagens foram realizadas antes e depois da ciclagem de escovação e comparadas quanto às alterações de superfície. A perda da estrutura superficial foi avaliada através dos métodos qualitativo e quantitativo. Para análise estatística dos dados obtidos, foram realizadas as medidas estatísticas: média, desvio padrão, mediana e percentis, avaliados inferencialmente através dos testes estatísticos Mann-Whitney, Kruskal-Wallis, com nível de significância de 5%. Resultado Maior índice de perda de estrutura superficial do esmalte nos grupos G2A (16,09) e G2B (11,38) e menor índice de perda estrutural nos grupos G5A (1,07) e G5B (1,20). Conclusão: Através desse estudo, observou-se que os dentifrícios clareadores e o Carvão Ativado são capazes de promover intenso desgaste do esmalte dentário.

Abstract Introduction Historically, abrasive materials such as marble powders, corals and bone ashes were used for dental hygiene. With evolution, these materials were replaced by dentifrices applied on toothbrushes for the same purpose. Objective To evaluate, through Optical Coherence Tomography, the wear of dental enamel after the use of different toothbrushes and materials used in brushing with abrasive components. Material and method 50 specimens were prepared, distributed in 10 groups (n=5) according to the toothpaste used. For group A, the Curaprox® Adult Ultra Macia toothbrush was used and for group B, the soft toothbrush K® - soft adult toothbrush. The following brushing materials were used: Curaprox® Black is White; Colgate® Luminous White Instant, Close Up® White Attraction - MenSuperpure; Activated Charcoal; Distilled Water. The images were performed before and after the brushing cycle and were compared for surface changes. The loss of the surface structure was evaluated through qualitative and quantitative methods. Statistical analysis of the data was performed using the statistical methods Mann-Whitney, Kruskal-Wallis, with significance level of 5%, mean, standard deviation, median and percentiles. Result A higher index of loss of enamel structure was observed in the G2A (16.09) and G2B (11.38) groups and a lower structural loss rate in the specimens corresponding to the groups G5A (1,07) and G5B (1,20). Conclusion Through this study it was observed that the whitening dentifrices and the Activated Charcoal are able to promote an intense wear of the dental enamel.

Avaliação da intensidade de luz e da manutenção dos aparelhos fotopolimerizadores utilizados em clínicas odontológicas da cidade do Recife-PE / Evaluation of light intensity and maintenance of light curing units used in clinics in the city of Recife

Objetivo: Avaliar os aparelhos fotopolimerizadores utilizados em clínicas da cidade do Recife e a manutenção realizada nesses aparelhos. Método: Os profissionais participaram da avaliação de forma voluntária e não foram identificados nos questionários que foram por eles respondidos. Foi perguntado sobre os métodos de desinfecção, a frequência de troca de lâmpadas e a frequência da técnica empregada de manutenção. Também foi realizada a avaliação do aparelho fotopolimerizador, registrando as informações referentes a modelo, marca e data de aquisição. Foi realizada a mensuração da intensidade de luz utilizando-se um radiômetro (Demetron®). Resultado: Todos os aparelhos fotopolimerizadores estavam com intensidade de luz inferior a 300 mW/cm2; 96,7% dos profissionais realizavam manutenção técnica de seus aparelhos apenas quando necessário; 100% trocavam a lâmpada só quando a mesma queimava; 40% dos aparelhos fotopolimerizadores encontravam-se acoplados ao equipo; 86,6% dos aparelhos apresentavam detritos na fibra óptica; 50% dos filtros apresentavam fraturas, sendo que 86,66% dos mesmos apresentavam detritos; 60% dos profissionais empregavam apenas álcool 70° como método de desinfecção; 53% dos entrevistados realizavam o método de desinfecção após cada paciente. Conclusão: Todos os aparelhos fotopolimerizadores avaliados estavam com intensidade de luz abaixo do preconizado e constatou-se a inexistência de um protocolo de manutenção preventiva periódica.

Objective: To evaluate the light curing equipment used in the Recife city clinics and maintenance performed on these devices. Method: The professionals participated in the evaluation voluntarily and were not identified in the questionnaires that were answered by them. He was asked about the disinfection methods, the frequency of changing bulbs and the technique often employed maintenance. It also promoted the evaluation of the curing light recording the information on the make, model and date of purchase. Measuring the light intensity using a radiometer (Demetron®) it was performed. Result: All light curing units were light intensity with less than 300mW/cm2; 96.7% of professionals performed the servicing of your appliances only when necessary; 100% exchanged the lamp only when it burned, 40% of light curing units found themselves attached to dental chair; 86.6% of the debris had apparatus in the optical fiber; 50% of filters had fractures, 86.66% of them had debris; 60% of professionals employed only 70° alcohol as disinfection method; 53% of respondents performed the disinfection method after each patient. Conclusion: All light curing units were evaluated with light intensity below the recommended and the absence of a periodic preventive maintenance protocol.