Longitudinal bond strength of a universal adhesive and chemical dentin characterization under different acid etching protocols.

OBJECTIVE: This study aimed to analyze the longitudinal bond strength of a universal adhesive and chemically characterize the dentin substrate under different acid etching protocols. METHODOLOGY: Dentin samples were etched with polyacrylic acid 25% (PAA) for 10 seconds (n=3) and phosphoric acid 32% (PA) for 15 seconds (n=3) and analyzed by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) before and after treatment. For collagen degradation, samples (n=12) were divided into 3 groups: PAA, PA, and Deionized water (control), and analyzed by the quantity of solubilized type I collagen C-terminal cross-linked telopeptides and solubilized C-terminal peptide in relation to total protein concentration (ICTPtp and CTXtp) and by their ultimate tensile strength (UTS). For the adhesive interface analysis, dentin samples (n=72) were divided into 3 groups: PAA, PA, and Self-etch (SE), and subdivided into 2 groups: 24 h (baseline) and 1 year. The following tests were performed: microtensile bond strength (µTBS) (n=48), scanning electron microscopy (SEM) (n=12), and nanoleakage (n=12). RESULTS: The FTIR of PAA showed lower reduction of the peaks in the phosphate group when compared to PA. For ICTPtp, PA showed a significantly higher value. For CTXtp, PA and PAA groups failed to statically differ from each other. UTS was significantly lower for PA. For µTBS, storage time significantly affected bond strength. The results were unaffected by the etching protocol. For SEM, after 1 year, PA had little evidence of degradation in the upper third of the adhesive interface in comparison to the other groups. Nanoleakage showed no considerable silver impregnation after 1 year in the SE group. CONCLUSION: The use of PAA prior to a universal adhesive (when compared to PA) represents a less aggressive type of etching to dentin. However, self-etching still seems to be the best option for universal adhesive systems that have functional monomers in their composition.

Longitudinal bond strength of a universal adhesive and chemical dentin characterization under different acid etching protocols

Abstract Objective This study aimed to analyze the longitudinal bond strength of a universal adhesive and chemically characterize the dentin substrate under different acid etching protocols. Methodology Dentin samples were etched with polyacrylic acid 25% (PAA) for 10 seconds (n=3) and phosphoric acid 32% (PA) for 15 seconds (n=3) and analyzed by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) before and after treatment. For collagen degradation, samples (n=12) were divided into 3 groups: PAA, PA, and Deionized water (control), and analyzed by the quantity of solubilized type I collagen C-terminal cross-linked telopeptides and solubilized C-terminal peptide in relation to total protein concentration (ICTPtp and CTXtp) and by their ultimate tensile strength (UTS). For the adhesive interface analysis, dentin samples (n=72) were divided into 3 groups: PAA, PA, and Self-etch (SE), and subdivided into 2 groups: 24 h (baseline) and 1 year. The following tests were performed: microtensile bond strength (μTBS) (n=48), scanning electron microscopy (SEM) (n=12), and nanoleakage (n=12). Results The FTIR of PAA showed lower reduction of the peaks in the phosphate group when compared to PA. For ICTPtp, PA showed a significantly higher value. For CTXtp, PA and PAA groups failed to statically differ from each other. UTS was significantly lower for PA. For μTBS, storage time significantly affected bond strength. The results were unaffected by the etching protocol. For SEM, after 1 year, PA had little evidence of degradation in the upper third of the adhesive interface in comparison to the other groups. Nanoleakage showed no considerable silver impregnation after 1 year in the SE group. Conclusion The use of PAA prior to a universal adhesive (when compared to PA) represents a less aggressive type of etching to dentin. However, self-etching still seems to be the best option for universal adhesive systems that have functional monomers in their composition.

Scientific writing with artificial intelligence: key considerations and alerts / Escrita científica com inteligência artificial: principais considerações e alertas

A integração de geradores de texto de inteligência artificial (IA) em relatórios científicos exige uma avaliação cuidadosa de considerações éticas específicas. Embora essas tecnologias de IA ofereçam suporte à geração de texto, abordar as implicações éticas é fundamental. Este editorial destaca a necessidade de uma abordagem ponderada e responsável, enfatizando o estabelecimento de diretrizes e melhores práticas por parte de pesquisadores e comunidades científicas. Esforços colaborativos entre desenvolvedores de IA, pesquisadores e comitês éticos podem garantir a integração perfeita das tecnologias de IA, ao mesmo tempo em que mantêm a integridade, qualidade e padrões éticos da divulgação científica. Este texto oferece um resumo abrangente considerações-chave ao se utilizar geradores de texto de inteligência artificial em relatórios científicos (AU)

The integration of artificial intelligence (AI) text generators in scientific reports demands careful evaluation of specific ethical considerations. While these AI technologies offer text generation support, addressing the ethical implications is vital. This editorial highlights the need for a thoughtful and responsible approach, emphasizing the establishment of guidelines and best practices by researchers and scientific communities. Collaborative efforts between AI developers, researchers, and ethical committees can ensure the seamless integration of AI technologies while upholding the integrity, quality, and ethical standards of scientific reporting. This text comprehensively summarizes the key considerations to be followed when utilizing artificial intelligence text generators in scientific reports.(AU)

Impact of photoinitiator quality on chemical-mechanical properties of dental adhesives under different light intensities / Impacto da qualidade de fotoiniciadores nas propriedades químico mecânicas de adesivos dentais sob diferentes intensidades de luz

Objective: Evaluate the mechanical properties of experimental adhesive models with different photoinitiators (PI) polymerized by LED units of different power densities. Material and Methods: Three groups of adhesive models based on HEMA/BisGMA (45/55) were prepared in association with different PI combinations: G2 (control) ­ 2 PI: 0.5% CQ, 0.5% EDMAB; G3 - 3 PI: 0.5% CQ; 0.5% DMAEMA, 0.5% DPIHP; G4 - 4 PI: 0.5% CQ; 0.5% EDMAB; 0.5% DMAEMA; 0.5% DPIHP. The three formulations were polymerized at two different LED power densities: 550 mW/cm2 and 1200 mW/cm2. The degree of conversion (DC) of adhesive monomers was monitored in situ through the FTIR for 600 s. Specimens were prepared for each formulation for analysis mong adhesive systems (G2

Objetivo: Avaliar as propriedades mecânicas de modelos adesivos experimentais com diferentes fotoiniciadores (PI) polimerizados por unidades de LED de diferentes densidades de energia. Material e Métodos: Três grupos de modelos adesivos baseados em HEMA/BisGMA (45/55) foram preparados em associação com diferentes combinações de PI: G2 (controle) ­ 2 PI: 0,5% CQ, 0,5% EDMAB; G3 - 3PI: 0,5% CQ; 0,5% DMAEMA, 0,5% DPIHP; G4 - 4 PI: 0,5% CQ; 0,5% EDMAB; 0,5% DMAEMA; 0,5% DPIHP. As três formulações foram polimerizadas em duas densidades de potência de LED: 550 mW/cm2 e 1200 mW/cm2. O grau de conversão (DC) dos monômeros adesivos foi monitorado in situ através do FTIR durante 600 s. Amostras foram preparadas para cada formulação para análise de resistência à flexão (FS), módulo de elasticidade (ME), sorção (SOR) e solubilidade (SOL). Os dados foram submetidos aos testes ANOVA 2-fatores e Tukey (5%). Resultados: DC: houve diferença significativa entre os sistemas adesivos (G2

How Water Content Can Influence the Chemomechanical Properties and Physical Degradation under Aging of Experimental Adhesives.

Objective: To evaluate the physicochemical (sorption (SOR), solubility (SOL), and degree of conversion (DC)) and mechanical (flexural strength (FS), modulus of elasticity (ME), and compressive strength (CS)) properties of adhesives with different water contents (D2O). Materials and Methods: An adhesive was formulated: 55 wt% BisGMA, 45 wt% HEMA, 0.5 wt% camphorquinone, 0.5 wt% EDMAB, and 1.0 wt% DPIHP. D2O was added into the adhesives (0 wt%, 10 wt%, and 16 wt%). DC was monitored through the FTIR. FS, ME, CS, SOR, and SOL were tested. The adhesive samples were aged in deionized water, ethanol, and acetone. Data were submitted to ANOVA and Tukey's tests (5%). Results: For DC, the 0 wt% group showed a significant reduction (68.09 ± 0.14A) compared with the 10 wt% (87.07 ± 0.81B) and 16 wt% groups (89.87 ± 0.24B); 10 wt% showed the highest FS (MPa) mean values (141.6 ± 6.71B) compared with the 0 wt% (109.4 ± 20.5A) and 16 wt% (107.8 ± 15.8A). For the CS (MPa) and ME (GPa), the 16 wt% showed the lowest mean values (98.8 ± 18.0B and 2.2 ± 0.3B, respectively) compared with the 10 wt% and 0 wt%. For the SOR, 16 wt% of water showed the highest mean values and the ethanol showed the lowest mean values of SOL regardless of water content. Conclusion: The amount of water content and the types of aging solvents significantly affect the adhesive properties.

Effect of fluoride, chlorhexidine or Nd:YAG on the progression of root dentin demineralization after removal of the demineralized organic matrix.

OBJECTIVES: Quantification of collagen degradation is an important parameter to evaluate dentin caries for preventive aid.. Evaluate preventive methods against root collagen degradation by the hydroxyproline assay (HYP) and microradiography technique (MRT). METHODOLOGY: Five bovine root dentin blocks were obtained and subjected to an artificial demineralization process by acetate buffer (pH 5) to induce carious lesion formation. Samples were subjected to the following therapeutic treatments: 1) 0.12% chlorhexidine for 1 min, 2) 2% fluoride for 1 min, 3) Nd:YAG Laser (400 µm diameter optical fiber, 10 Hz frequency, 60 mJ/pulse energy, 48 J/cm2 energy density, in noncontact mode for 10 s), 4) deionized water (control) for 1 min, 5) MRT control group (without treatment and removal of collagen). Samples were exposed to degradation by a collagenase enzyme for five days. The enzyme solution was collected, by colorimetry in a spectrophotometer, from the collagen matrix for the hydroxyproline release analysis. The same samples were subjected to an additional two days of demineralization to induce the progression of mineral loss. Samples were analyzed by MRT for the visualization of their degraded areas (estimation of lesion depth and mineral loss). ANOVA was applied to compare hydroxyproline release rates. MRT data were subjected to the Kruskal-Wallis test, followed by the Dunn's test. Comparisons between the initial five-day and the subsequent two-day demineralization processes were performed by repeated t-test or Wilcoxon (p<0.05) measurements. RESULTS: The amount of HYP released from the dentin samples failed to show significant differences among the groups (p=0.09). Fluoride and chlorhexidine were able to interact with the samples, reducing the progression of dentin caries after removal of the demineralized organic matrix. CHX was the only treatment able to show significant lower lesion depth than the negative control. CONCLUSION: Chlorhexidine and fluoride were effective in reducing root caries progression.

Universal adhesive: the effect of different simulated pulpal pressure fluids and bonding modes to dentin.

The aim of this study was to evaluate the effect of SPP with either fetal bovine serum (FBS) or deionized water (DW) on the bond strength (µTBS) of a Universal adhesive to dentin, in both etch-and-rinse (ER) and self-etch (SE) modes. The kinematic viscosity (cSt) of FBS and DW was measured at 25 °C ± 0.1 ºC. Seventy-two sound human molars were sectioned and randomly divided into three groups according to the SPP conditions: (1) Control (0 cm H2O), (2) SPP (15 cm H2O) with FBS, (3) SPP (15 cm H2O) with DW. Each group was subdivided (n = 10) based on the bonding modes: ER (37% phosphoric acid + ScothBond Universal Adhesive) or SE (ScothBond Universal Adhesive). Samples were then submitted to µTBS. Data were analyzed by Student's t test, two-way ANOVA and Tukey tests (p < 0.05). The cSt results showed that DW (23.59 ± 0.39) had significantly higher values than FBS (22.33 ± 0.06). With regard to SPP, the control group (36.1 MPa) had significantly higher values of µTBS when compared to the SPP using FBS (31.06 MPa) and SPP with DW (26.55 MPa). According to ANOVA, the bonding modes and the interaction of simulated pulpal pressure (SPP) did not statistically influence the results (p < 0.05). The presence of SPP reduced the bond strength of Universal adhesive to dentin. DW during SPP had significantly reduced bonding values when compared to FBS. Bonding strategies were not affected by SPP when evaluated in a short period of time (24 h).

Effect of fluoride, chlorhexidine or Nd:YAG on the progression of root dentin demineralization after removal of the demineralized organic matrix

Abstract Quantification of collagen degradation is an important parameter to evaluate dentin caries for preventive aid. Objectives: Evaluate preventive methods against root collagen degradation by the hydroxyproline assay (HYP) and microradiography technique (MRT). Methodology: Five bovine root dentin blocks were obtained and subjected to an artificial demineralization process by acetate buffer (pH 5) to induce carious lesion formation. Samples were subjected to the following therapeutic treatments: 1) 0.12% chlorhexidine for 1 min, 2) 2% fluoride for 1 min, 3) Nd:YAG Laser (400 μm diameter optical fiber, 10 Hz frequency, 60 mJ/pulse energy, 48 J/cm2 energy density, in noncontact mode for 10 s), 4) deionized water (control) for 1 min, 5) MRT control group (without treatment and removal of collagen). Samples were exposed to degradation by a collagenase enzyme for five days. The enzyme solution was collected, by colorimetry in a spectrophotometer, from the collagen matrix for the hydroxyproline release analysis. The same samples were subjected to an additional two days of demineralization to induce the progression of mineral loss. Samples were analyzed by MRT for the visualization of their degraded areas (estimation of lesion depth and mineral loss). ANOVA was applied to compare hydroxyproline release rates. MRT data were subjected to the Kruskal-Wallis test, followed by the Dunn's test. Comparisons between the initial five-day and the subsequent two-day demineralization processes were performed by repeated t-test or Wilcoxon (p<0.05) measurements. Results: The amount of HYP released from the dentin samples failed to show significant differences among the groups (p=0.09). Fluoride and chlorhexidine were able to interact with the samples, reducing the progression of dentin caries after removal of the demineralized organic matrix. CHX was the only treatment able to show significant lower lesion depth than the negative control. Conclusion: Chlorhexidine and fluoride were effective in reducing root caries progression.

Amalgam allergy and Burning Mouth Syndrom: treatment and 25 years recall / Alergia ao amálgama e Síndrome da ardência bucal: tratamento e 25 anos de proservação

Background: Burning mouth syndrome (BMS) is a non-neuropathic chronic orofacial pain condition, characterized by the presence of burning/warm sensation without specific mucosal lesions. Objective: The aim of the present clinical case report is to describe the positive outcome of dental treatment of a patient with BMS and followed up for 25 years. Data Treatment: This report describes the case of a 50-year-old black woman sought treatment for burning, and persistent swelling of tong (24h/day) occurring over years. Clinical evaluation of the oral environment revealed the tongue with cracking, darkened points areas, surrounded by whitish areas. Twelve teeth presented extensive amalgam restorations. Patch testing revealed a very strong hypersensitivity to Amalgam. All amalgam restorations were substituted by composite resin restorations. Results and Conclusion: Burning sensation disappeared completely after these restorations had been changed. After 25-year follow-up period, it was observed that burning sensation has never been felt anymore. Clinical Significance: Burning mouth syndrome is a chronic orofacial pain, usually without specific mucosal lesions. The etiology is complex and multifactorial and the treatment should be made specifically for each pacient. (AU)

Introdução: A síndrome de ardência bucal (SAB) é uma condição de dor orofacial crônica não neuropática, caracterizada pela presença de sensação de queimação/calor sem lesões específicas da mucosa. Objetivo: Oobjetivo do presente relato de caso clínico é descrever a evolução positiva do tratamento odontológico de uma paciente com SAB e o retorno após 25 anos. Tratamento dos Dados: Este relato descreve o caso de uma mulher negra de 50 anos que buscou tratamento por queimadura e edema persistente da língua (24h/dia) ocorrendo ao longo dos anos. A avaliação clínica da cavidade bucal revelou a língua com áreas fissuradas e áreas com pontos escurecidos circundadas por áreas esbranquiçadas. Doze dentes apresentavam restaurações extensas de amálgama de prata. O teste de contato revelou hipersensibilidade muito forte ao amálgama de prata. Todas as restaurações de amálgama de prata foram substituidas por restaurações de resina composta. Resultados e Conclusão: A sensação de queimação desapareceu completamente após a substituição das restaurações. Após um periodo de 25 anos, observou-se que a sensação de queimação nunca foi mais relatada. Significado Clínico: a síndrome da ardência bucal é uma dor orofacial crônica, geralmente sem lesões específicas da mucosa. A etiologia é complexa e multifatorial e o tratamento deve ser feito especificamente para cada paciente.(AU)

Full digital workflow in fixed adhesive dental prosthesis: Description of a clinical technique / Fluxo de trabalho digital completo em prótese fixa adesiva: descrição de uma técnica clínica

Digital dentistry has gained space in several dental specialties. It is possible to achieve excellent results with the digital workflow, which combines the efficiency of the restorative material with a greater marginal adaptation. This study aimed to report a clinical case through the digital workflow, with a faster and clinically acceptable prosthetic resolution. In this clinical case report, digital workflow allowed a faster and clinically acceptable prosthetic resolution. A 45-year-old female patient reported cementation failure of the prosthetic crown on tooth 14. As it was a vital tooth, the tooth received a total crown preparation. In the same clinical session, the patient's mouth was scanned then a capture software obtained a virtual model. After, the design software planned a digital "diagnostic wax-up", so a leucitic ceramic was chosen for the rehabilitation. The ceramic block was milled and receive stain and glaze, dispensing the prosthesis laboratory. Then, the adhesive cementation was performed with a dual-polymerized resin cement. The final crown had ideal adaptation, with no need for interproximal and occlusal adjustments, with an excellent marginal fit. Within the limitations of this study, this case report showed that the digital workflow allowed a favorable result in a shorter working time, which brought back function and aesthetics, without the need for interproximal and occlusal adjustments. (AU)

A odontologia digital vem ganhando espaço em diversas especialidades odontológicas. Com o fluxo de trabalho digital, é possível alcançar excelentes resultados na reabilitação protética, combinando a eficiência do material restaurador com a adaptação marginal proporcionada pela odontologia digital. O objetivo desse estudo foi relatar um caso clínico através do fluxo de trabalho digital, com uma resolução protética mais rápida e clinicamente aceitável. Paciente do sexo feminino, 45 anos, relatou falha de cimentação da coroa protética do dente 26. Por ser um dente vital, o dente recebeu um preparo de coroa total e os dentes foram escaneados e um software de captura obteve um modelo virtual. Posteriormente, o software de projeto planejou um "enceramento diagnóstico" digital, sendo escolhida uma cerâmica leucítica para a reabilitação. O bloco cerâmico foi fresado e recebeu acabamento, maquiagem e glaze pelo próprio dentista, dispensando um técnico laboratorial de prótese dentária. Em seguida, foi realizada cimentação adesiva definitiva. Este relato de caso mostra que, dentro das limitações desse estudo, o fluxo digital permite um resultado favorável em um menor tempo de trabalho, devolvendo a função e estética, sem necessidade de ajustes interproximais e oclusais (AU)

Polyphenol-enriched extract of Arrabidaea chica used as a dentin pretreatment or incorporated into a total-etching adhesive system: Effects on bonding stability and physical characterization.

The aim of this paper was to evaluate the physical properties and the long-term bond strength of a 2.5% polyphenol-enriched extract of Arrabidaea chica (AC) incorporated into both the phosphoric acid and the primer of a three-step total-etch adhesive, or into an aqueous solution as a dentin pretreatment. Fifty dentin surfaces received the treatments (n = 10): CON (control) - application of the three-step adhesive system (Adper Scotchbond Multipurpose, 3M ESPE); WAT - distilled water used as a pretreatment after dentin etching and before application of the adhesive system; ACPA - AC incorporated into the phosphoric acid; ACW - dentin pre-treatment with AC incorporated into an aqueous solution after etching; ACP - AC incorporated into the primer. Microtensile bond strength tests were performed after 24 h, 6 and 12 months of storage. Slices from the resin-dentin interface were obtained for scanning electron microscopy analysis of the hybrid layer. Degree of conversion of AC incorporated into the primer was evaluated. The particle size, polydispersity index and zeta potential of all the solutions prepared by incorporating AC (phosphoric acid, primer and distilled water) were measured by dynamic light scattering, which brought about changes after incorporation. Degree of conversion of the primer was not affected after incorporating AC. ACP showed lower microtensile bond strength values than the other groups. Bond strength decreased after 6 months of storage, stabilizing at the 12-month evaluation. Therefore, use of AC incorporated into the primer led to lower bond strength values, since AC modified the physical properties (particle size, polydispersity index and zeta potential) of the primer, but did not change the degree of conversion. Application of AC as a dentin pretreatment did not affect bond strength or the micromorphological characteristics of the hybrid layer.

A 2-year clinical evaluation of direct and semi-direct resin composite restorations in non-carious cervical lesions: a randomized clinical study.

OBJECTIVES: The purpose of this study was to evaluate the 2-year success of resin composite restorations in non-carious cervical lesions (NCCLs) using the direct or semi-direct techniques. MATERIALS AND METHODS: Thirty volunteers presenting with at least two NCCLs were included. Each participant received one restoration using the direct technique and the other using the semi-direct technique, totaling 60 restorations. Time for completing the treatment was computed. Assessments at baseline, 7 days, and 6, 12, and 24 months were performed using the modified United States Public Health Service criteria. Descriptive analysis was reported as a percentage of successful treatments. For inferential analysis, the Student t test was used to evaluate the differences between extension, depth, and time. The chi-square/Fisher tests were used to compare treatment success after each period (α = 0.05). The results were evaluated by using the Kaplan-Meier survival analysis. RESULTS: Differences were detected regarding mean ± standard deviation time, in which direct and semi-direct procedures were accomplished in 21.8 (± 14.5) and 35.3 (± 19.9) min, respectively. Of the 60 restorations placed, 7 failed in the direct group while 8 failed in the semi-direct group up to 2 years. No differences were detected between restorative protocols. The cumulative survival was 88.5% and 88.4% for the direct technique and semi-direct techniques after 24 months, respectively. CONCLUSION: The tested restorative protocols present similar results for NCCLs within the studied periods. CLINICAL RELEVANCE: The semi-direct technique exhibited clinical performance similar to direct technique for NCCL, demonstrating an alternative for restorations of these lesions.

Protocols to control contamination and strategies to optimize the clinical practice in Restorative Dentistry during the COVID-19 pandemic / Protocolos para controle de contaminação e estratégias para otimizar a prática clínica em Odontologia Restauradora durante a pandemia de COVID-19

The current outbreak of coronavirus 2019 (COVID-19) challenges how professional standards have been defined so far. In Dentistry, biosafety measures already taken by professionals have been intensified, aiming to offer the patient urgent and emergency treatment with safety for both. In this context, Restorative Dentistry is responsible for the care of patients with caries injuries, with or without symptoms and, fractures of teeth and existing restorations. This article guides professionals, during the pandemic period, on the risks involved in adult and pediatric dental care for patients with restorative needs. It also discusses strategies to optimize clinical practice, reducing risks of contamination and virus transmission. (AU)

O atual surto de coronavírus 2019 (COVID-19), fez com que muitos profissionais repensassem sua postura de trabalho. Na Odontologia, medidas de biossegurança já realizadas pelos profissionais, foram intensificadas, com o objetivo de oferecer ao paciente um tratamento de urgência e emergência com segurança para ambos. Neste contexto, a Odontologia Restauradora é responsável pelo atendimento de pacientes com lesões de cárie, com ou sem sintomatologia, e fraturas de dentes e restaurações já existentes. Este trabalho orienta os profissionais quanto aos riscos envolvidos no atendimento odontológico, adulto e pediátrico, de paciente com necessidades restauradoras durante o período de pandemia. O artigo também discute estratégias para otimizar o atendimento, diminuindo riscos de contaminação e transmissão do vírus. (AU)

Photodynamic inactivation of planktonic cultures of Streptococcus mutans using erythrosine irradiated by LED / Inativação fotodinâmica de culturas planctônicas de Streptococcus mutans usando eritrosina irradiada por LED

Objective: The aim of this in vitro study was to evaluate the efficacy of photodynamic inactivation (PDI) with erythrosine (E), using a light-emitting diode (LED) on planktonic cultures of Streptococcus mutans. Material and Methods: A Streptococcus mutans strain (UA 159) was used to prepare the suspensions containing 107 cells/mL, which was tested under different experimental conditions: a) LED irradiation in the presence of erythrosine as a photosensitizer (E+L+); b) LED irradiation only (P-L+); c) treatment with erythrosine only (E+L-); and d) no LED irradiation or photosensitizer (P) treatment, which served as a control group (P-L-). After treatment, strains were seeded onto MSBS agar for determination of the number of colony-forming units (CFU/mL). Results: The results were submitted to analysis of variance and the Tukey test (p < 0.05). No reduction in the number of CFU/mL was observed in the treatment group with erythrosine (E+L+) when compared to the control (P-L-). Conclusion: PDI using erythrosine did not reduce the number of CFUs per millimeter within the parameters in this study. (AU)

Objetivo: o objetivo deste estudo in vitro foi avaliar a eficácia da inativação fotodinâmica (PDI) com a eritrosina (E), usando diodo de emissão de luz azul (LED) em culturas planctônicas de Streptococcus mutans. Material e métodos: a cepa de Streptococcus mutans (UA 159) foi usada para o preparo das suspensões padrões contendo 107 células/mL, as quais foram testadas em diferentes condições experimentais a) irradiação com LED em presença da eritrosina como fotossensibilizador (E+L+); b) irradiação com LED apenas (F-L+); c) tratamento com eritrosina apenas (E+L-); e d) tratamento sem irradiação com LED ou fotossensibilizador (F), que serviu como grupo controle (F-L-). Após o tratamento, as cepas foram semeadas em ágar MSBS para determinação do número de unidades formadoras de colônias (UFC/mL). Resultados: os resultados foram submetidos à análise de variância e teste de Tukey (p < 0.05). Não foi observada redução no número de UFC/mL no grupo de tratamento com eritrosina (E+L+) quando comparado ao grupo controle (F-L-). Conclusão: a PDI usando etritrosina e LED não reduziu o número de UFCs por milímetro com os parâmetros utilizados neste estudo.(AU)

Analysis of adhesive bond strength under simulated pulpal pressure during laser irradiation on different dentin thicknesses / Análise da resistência adesiva sob pressão pulpar simulada durante irradiação laser em diferentes espessuras de dentina

Objective: Evaluate the microtensile bond strength (µTBS) in different dentin thicknesses, under simulated pulpal pressure (SPP), submitted to an adhesive technique using laser irradiation. Material and methods: Forty sound human molars were sectioned and randomly divided into two groups (n=20): Group 1 ­ 1 mm of dentin thickness; Group 2 ­ 2 mm of dentin thickness. Each group was divided into two subgroups (n=10): Subgroup A ­ Absence of SPP; Subgroup P ­ Presence of SPP (15 cm H2 O). The samples were sequentially treated with: 37% phosphoric acid, adhesive system (Adper Single Bond 2), Nd:YAG laser irradiation (60 s, 1064 nm, 10 Hz) using 60 and 100 mJ/pulse energy parameters and photopolymerization (10 s). A composite resin block (Filtek Z350) was built up onto the irradiated area. After 30 days stored in water, the samples were sectioned and submitted to microtensile test (10 kgf load cell, 0.5mm/min). Data were analyzed by twoway ANOVA and Tukey tests. Results: Two-way ANOVA revealed no significant differences for SPP on bond strength. The laser energy parameters indicated that 100 mJ showed greater µTBS means compared to the group irradiated with 60 mJ. The presence of SPP reduced the mean µTBS values. Conclusions: Simulated pulpal pressure did not affect the µTBS using 60 mJ of laser energy parameter. At 100 mJ, the presence of SPP negatively influenced the bond strength, regardless of dentin thickness (AU)

Objetivo: O objetivo deste estudo foi avaliar a resistência adesiva (RA) em diferentes espessuras de dentina, associada à pressão pulpar simulada (PPS), quando submetidos à técnica adesiva por irradiação laser. Material e Métodos: Quarenta molares humanos hígidos foram seccionados e divididos aleatoriamente em dois grupos (n=20): Grupo 1 ­ 1 mm de espessura de dentina; Grupo 2 ­ 2 mm de espessura de dentina. As amostras foram divididas em 2 subgrupos (n=10): Subgrupo A ­ ausência de PPS; Subgrupo P ­ presença de PPS (15 cm de H2 O). As amostras foram tratadas seqüencialmente com: ácido fosfórico 37%, sistema adesivo (Adper Single Bond 2), irradiação com Nd:YAG laser (60 s, 1064 nm, 10 Hz) nos parâmetros de energia de 60 e 100 mJ/pulso e fotopolimerização (10 s). Um bloco de resina composta (Filtek Z350, 3M ESPE) foi confeccionado sobre a área irradiada. Após 30 dias armazenados em água, os espécimes foram seccionados e submetidos ao teste de microtração (carga de 10 kgf, 0.5mm/min). Os dados foram analisados pelos testes ANOVA sob 2 fatores e Tukey (p<0.05). Resultados: ANOVA mostrou que não houve diferenças significativas para PPS na RA. Para os parâmetros de energia do laser, 100 mJ apresentou maiores médias de RA quando comparado ao grupo irradiado à 60 mJ. A presença da PPS reduziu as médias de RA. Conclusão: Pressão pulpar simulada não afetou os valores de resistência adesiva para o grupo irradiado com 60 mJ. Para 100 mJ, a presença da pressão pulpar influenciou negativamente na resistência adesiva, independente das espessuras de dentina.(AU)

Mechanical-physicochemical properties and biocompatibility of catechin-incorporated adhesive resins.

OBJECTIVES: Several anti-proteolytic dentin therapies are being exhaustively studied in an attempt to reduce dentin bond degradation and improve clinical performance and longevity of adhesive restorations. This study assessed the effect of epigallocatechin-3-gallate (EGCG) on long-term bond strength when incorporated into adhesives. MATERIAL AND METHODS: Adhesive systems were formulated with EGCG concentrations of 0 wt%: (no EGCG; control); 0.5 wt% EGCG; 1.0 wt% EGCG, and 1.5 wt% EGCG. Flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), compressive strength (CS), degree of conversion (DC), polymerization shrinkage (PS), percentage of water sorption (%WS), percentage of water solubility (%WL) and cytotoxicity properties were tested. Dentin microtensile bond strength (µTBS) was evaluated after 24 h and again after 6 months of water storage. The adhesive interface was analyzed using scanning electron microscopy (SEM). RESULTS: No significant differences were found among the groups in terms of FS, ME, MR, CS and PS. EGCG-doped adhesives increased the DC relative to the control group. EGCG concentrations of 1.0 wt% and 0.5 wt% decreased the WS of adhesives. WL decreased in all cases in which EGCG was added to adhesives, regardless of the concentration. EGCG concentrations of 1.0 wt% and 0.5 wt% reduced cytotoxicity. EGCG concentrations of 1.0 wt% and 0.5 wt% preserved µTBS after 6 months of storage, while 1.5 wt% EGCG significantly decreased µTBS. SEM: the integrity of the hybrid layer was maintained in the 0.5 wt% and 1.0 wt% EGCG groups. CONCLUSION: EGCG concentrations of 1.0 wt% and 0.5 wt% showed better biological and mechanical performance, preserved bond strength and adhesive interface, and reduced cytotoxicity.

Staining Beverages and Cigarette Smoke on Composite Resin and Human Tooth Fluorescence by Direct Spectrometry.

INTRODUCTION: This study evaluated the fluorescence intensity (FI) of different brands of composite resins (CRs) and compare those values with the FI of human tooth, under the action of cigarette smoke (CI), coffee (CA), and soft drink (CO), measured by direct spectrometry. MATERIALS AND METHODS: A total of 30 specimens of each brand (Filtek Z350, Esthet-X, Amelogen, Durafill) were made. Others 30 tooth specimens (3 mm/diameter) were obtained from human molars using a trephine bur. The specimens were randomly divided into three groups (n = 10), according to substances: CI, CA, CO. The FI was directly measured using an optic fiber associated with a spectrometer and was measured at baseline and after staining. Data were submitted to Kruskal-Wallis, Dunnett, and Dunn tests. RESULTS: Staining influenced FI mean values among CRs and between those with human tooth. Z showed the closest FI mean values of tooth after staining. CONCLUSION: Staining beverages and cigarette smoke negatively influenced on FI of CR and human tooth. CLINICAL SIGNIFICANCE: The study shows darkening treatments influenced on the fluorescent property of the dental tissues and restorative materials according to the direct spectrometry analysis.

Guidelines for conducting split-mouth clinical studies in restorative dentistry / Guia para condução de estudos em boca dividida em dentistica

O desenho experimental proposto em estudos clínicos do tipo boca dividida objetivam uma aleatorização em nível local, no qual dois tratamentos são randomizados em cada um dos lados da boca. O objetivo dessa revisão foi resumir em um guia as normas para condução de estudos clínicos do tipo boca dividida na área de Dentística Restauradora. Foram selecionados estudos clínicos indexados nas bases de dados MEDLINE, PubMed e Scielo, entre 2004 e 2014, que utilizaram o critério USPHS ou FDI. O presente guia mostrou as principais características que devem ser consideradas em estudos do tipo boca dividida na área de Dentística, tais como os aspectos éticos, calculo amostral, métodos de seleção e avaliação e pacientes, como forma de facilitar e conduzir estudos clínicos. (AU)

The split-mouth design used in some clinical trials make a randomization scheme on site level where two treatments are randomly assigned to sites of one of the two halves of the mouth. The aim of this review was to summarize guidelines for conducting split-mouth clinical studies in Restorative Dentistry. This is a review performed through scientific articles published between 2004 and 2014 indexed in MEDLINE, PubMed and Scielo databases. The study evaluated USPHS and FDI criteria. The current review showed the main characteristics used in splitmouth studies presented the Restorative Dentistry literature, as ethical aspects, sample calculation, methods of selection and evaluation patients, in order to provide a guideline for clinical conduction. It showed a standard of methodologies to enable comparison among studies.(AU)

Influence of simulated pulpal pressure on the variation of intrapulpal temperature during adhesive system light-curing / Influência da pressão pulpar simulada na variação de temperatura intrapulpar durante a fotopolimerização do sistema adesivo

Objective: To evaluate the effects of simulated pulpal pressure (SPP) on the variation of intrapulpal temperature (T) during lightcuring of the adhesive system. Material and Methods: One hundred sound human molars were sectioned from the highest pulp horn to obtain a 2-mm of thickness dentin. The specimens were randomly divided into two groups: (n = 50), according to the presence or absence of SPP (15 cm H2 O). The specimens were sequentially treated as follows: 37% phosphoric acid (Scotchbond Universal; 3M/ESPE), adhesive system (Scotchbond Universal/3M ESPE) and light-curing (10 s). T was evaluated during adhesive lightcuring with a K-type thermometer put inside the pulp chamber. Data were analysed by using Mann-Whitney's test (at 5%). Results: According to Mann-Whitney's test, the absence group presented a T of 2 °C, whereas the presence group 1 °C. The mean values of T were 0.82 ± 0.56 °C for the presence group and 2.30±0.73 °C for the absence group. Conclusion: Simulated pulpal pressure significantly reduced the temperature rise in the pulp chamber during light-curing of the adhesive system, showing the importance of inserting this protocol of simulated pulpal pressure in the laboratory procedures.(AU)

Objetivos: Avaliar os efeitos da pressão pulpar simulada (PPS) na variação de temperatura (DT) durante a fotopolimerização do sistema adesivo. Material e Método: Cem molares humanos hígidos foram seccionados para obtenção de 2 mm de espessura de dentina, a partir do corno pulpar mais alto. As amostras foram divididas aleatoriamente em 2 grupos (n = 50): ausência e presença de PPS (15 cm de H2 O). As amostras foram tratadas seqüencialmente com: ácido fosfórico 37% (Scotchbond Universal; 3M/ESPE), sistema adesivo (Scotchbond Universal/3M ESPE), seguida da fotopolimerização (10 s). Na seqüência, um bloco de resina composta (Filtek Z350 XT; 3M/ESPE) foi confeccionado sobre a área preparada. Para a fotopolimerização, utilizou-se o fotopolimerizador LED Light Curing System - Demi Plus (Kerr Corporation, Middleton, WI, USA), com potência de 1200 mW/cm2 . A DT foi avaliada durante a fotopolimerização do adesivo por meio de um termômetro digital no interior da câmara pulpar. Os dados obtidos foram avaliados pelo MannWhitney test (5%). Resultados: Segundo Mann-Whitney test, o grupo ausência sofreu DT de 2 °C, enquanto o grupo presença variou 1 °C. Os valores de média da DT foram de 0.82±0.56 °C para o grupo presenca de PPS e 2.30 ± 0.73 °C para o grupo ausência de PPS. Conclusão: A pressão pulpar simulada reduziu significantemente a elevação de temperatura na câmara pulpar durante a fotopolimerização do sistema adesivo, demonstrando a importância de inserir esse protocolo de simulação de pressão pulpar nos procedimentos laboratoriais.(AU)

Additional chemical polymerization of dual resin cements: reality or a goal to be achieved? / Polimerização química adicional de cimentos resinosos duais: realidade ou um objetivo a ser atingido?

Introduction:This study serves as a warning to dentists and researchers that dual-cured resin cements may not polymerize completely under some prosthetic crowns. Objective: The aim of this study was to analyse the polymerization degree of dual-cured resin cements under prosthetic barrier, by microhardness test. Material and method: Three cements (Bistite II, RelyX ARC and Variolink II) were light-cured through different barriers, placed between the cement and the light source: G1: without barrier; G2: composite resin (Cesead); G3: Inceram alumina; G4: IPS Empress; G5: Inceram zirconia; G6: tooth fragment. Photopolymerization was carried out using a halogen light unit (650 mW/cm2); microhardness was evaluated using the Microhardness Tester FM 700, under a load of 50gf with a dwell time of 15s, at two evaluation times (30min and 24h). Result: The results were submitted to ANOVA and Tukey tests (5%). Both Inceram alumina and Inceram zirconia ceramic barriers hindered polymerization. Bistite, followed by RelyX and Variolink, exhibited the highest microhardness values (p< 0.05). As the highest values were obtained without a barrier, it was determined that the barrier, followed by the tooth, influenced microhardness. Both Empress and Cesead had the smallest microhardness values but with no statistically significant difference between them. Conclusion: The barrier negatively affected the microhardness of dual-cured resin cements; evaluation time did not affect microhardness values for most of the conditions tested. There is a limited effect of the chemical activator on the polymerization of some dual-cured cements, and their performance is product specific.

Introdução: Este trabalho serve como um alerta para dentistas e pesquisadores, que alguns cimentos resinosos duais podem não polimerizar completamente sob alguns tipos de coroas protéticas. Objetivo: Analisar o grau de polimerização de cimentos resinos duais, sob barreiras protéticas, por teste de microdureza. Material e método: Três cimentos: Bistite II, RelyX ARC e Variolink II, foram fotopolimerizados através da interposição de vários tipos de barreiras, interpostas entre o cimento e a fonte de luz, formando os grupos: G1: sem barreira; G2: Resina composta Cesead; G3: Inceram alumina/Allceram; G4: IPS Empress; G5: Inceram zircônia/Allceram; G6: fragmento dental. Utilizou-se a luz halógena (650 mW/cm2) para fotoativação e a microdureza foi avaliada: 50gf durante 15s (MicrohardnessTester FM 700), em dois períodos (30min e 24h) pós ativação. Os dados foram submetidos à ANOVA e teste de Tukey (5%). As interposições de Inceram alumina e Inceram zircônia resultaram na polimerização deficiente dos cimentos, impossibilitando a realização dos ensaios. Resultado: Para o fator cimento, o Bistite revelou a maior microdureza, seguido do RelyX e do Variolink (p< 0,05). A barreira influenciou a microdureza, sendo que os maiores valores foram obtidos sem barreira, seguida do dente. Empress e Cesead proporcionaram os menores valores de microdureza e não diferiram entre si. Conclusão: A barreira afetou negativamente a microdureza dos cimentos resinosos duais; o período de avaliação não afetou os valores de microdureza para quase todas as condições testadas; existe um fator limitante do ativador químico na polimerização de alguns cimentos resinosos duais, e seu desempenho é dependente do produto.