Academics knowledge about tooth bleaching: technical and ethical issues / Conhecimento de acadêmicos acerca do clareamento dental: questões técnicas e éticas

ABSTRACT Objective: The aim of this study was to evaluate the level of knowledge of UFES dental students about home bleaching treatment. Methods: As a methodology, a descriptive and cross-sectional study was carried out through the application of practice to 109 students, containing questions about home tooth whitening, technical care and possible complications of the treatment. Data were tabulated and submitted to descriptive statistics. Results: Of the total number of students, 88.99% said they knew the factors that limit or contraindicate the bleaching treatment, 16.51% of students recognize hydrogen peroxide as a possible inducer of oral cancer, 30.27% of the students had their teeth whitened inside the University, 44.03% had their teeth whitened outside the University without professional supervision. In addition, 56.88% believe anamnesis and clinical examination are necessary before the bleaching treatment. Conclusion: It is concluded that students have limited knowledge about certain points of at-home tooth whitening. Students know the risk factors of bleaching treatment, except regarding hydrogen peroxide being a possible inducer of oral cancer. It can be inferred that academics highlight the importance of associating the clinical examination with the patient's anamnesis before performing the bleaching treatment. Most students have had their teeth whitened outside the University, which calls attention to reinforce knowledge about the ethical issues of the profession.

RESUMO Objetivo: O objetivo deste estudo foi avaliar o nível de conhecimento dos acadêmicos de odontologia da UFES sobre o tratamento clareador caseiro. Métodos: Como metodologia, foi realizado um estudo descritivo e transversal por meio da aplicação de questionário a 109 estudantes contendo perguntas sobre o clareamento dental caseiro, cuidados técnicos e possíveis riscos do tratamento. Os dados foram tabulados e submetudos à estatística descritiva. Resultados: Do total de estudantes, 88,99% disse conhecer os fatores que limitam ou contraindicam o tratamento clareador; 16,51% dos estudantes reconhecem o peróxido de hidrogênio como possível indutor de câncer bucal; 30,27% dos estudantes realizaram o clareamento dental dentro da Universidade, 44,03% realizaram o clareamento dental fora da Universidade sem supervisão profissional. Além disso, 56,88% acreditam que são necessários anamnese e exame clínico antes de realizar o tratamento clareador. Conclusão: Conclui-se que os alunos têm conhecimento limitado sobre determinados pontos do clareamento dental caseiro. Os estudantes conhecem os fatores de risco do tratamento clareador, exceto a respeito do peróxido de hidrogênio ser um possível indutor de câncer bucal. Pode-se inferir que os acadêmicos relevam a importância da associação do exame clínico com a anamnese do paciente antes de se realizar o tratamento clareador. A maioria dos estudantes tem realizado o clareamento dental fora da Universidade, o que chama atenção para reforçar o conhecimento sobre as questões éticas da profissão.

Influence of chlorhexidine, propolis, pulpal pressure simulation, and aging on dentin bond strength.

The present study evaluated the bond strength (µTBS) of dentin treated with chlorhexidine and propolis subjected to simulated pulpal pressure (SPP) and thermocycle aging. One hundred and twenty healthy human molars were sectioned to obtain 2 mm of dentin thickness and were divided into two groups (n = 60): SPP (15 cm H2 O) and no SPP (Control group). Dentin surfaces were conditioned with 37% phosphoric acid for 15 s and were divided according to the dentin treatment (n = 20): Control; Chlorhexidine gluconate (0.2% for 30 s) and Propolis (aqueous propolis extract for 30 s). Half of the specimens were submitted to 15,000 thermocycle aging (5 ± 2°C and 55 ± 2°C). The samples were sectioned into beams and submitted to µTBS. Data were analyzed by three-way ANOVA (SPP × Dentin treatment × Thermocycle aging) and the Tukey's tests (p < .001). With regard to the SPP, ANOVA revealed that the Control group (32.98 MPa) had significantly higher values of µTBS when compared to the SPP (29.19 MPa). With regard to Thermocycle aging, no aging (34.05 MPa) had significantly higher values of µTBS when compared to the aging (28.12 MPa). With regard to the dentin treatment, Propolis and Chlorhexidine did not statistically influence the results (p > .05). The SPP and thermocycle aging negatively influenced the bond strength between the dentin and resin; the 0.2% chlorhexidine digluconate and aqueous propolis extract solutions did not interfere in the bond strength between the resin and dentin. The use of chlorhexidine and propolis as a dental treatment may not influence the dentin bond strength, but SPP and thermocycle aging may damage the longitudinal dentin bond strength. RESEARCH HIGHLIGHTS: Chlorhexidine and propolis as a dental treatment may not influence the dentin bond strength. Simulated pulpal pressure and thermocycle aging may damage the longitudinal dentin bond strength.

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.

Linear dimensional accuracy of stereolithographic surgical guide after chemistry and physics sterilization.

OBJECTIVES: The purpose of this study was to evaluate the dimensional stability of prototyped surgical guides after autoclave and 2% glutaraldehyde sterilization processes. MATERIAL AND METHODS: Twenty prototyped surgical guides were prepared and submitted to two sterilization processes (n = 10): Physics - sterilization by autoclave (saturated water vapor under pressure, temperature of 126 to 130 °C, pressure of 1,7 at 1.9 kgf/cm2, 16 min); Chemistry - sterilization by 2% glutaraldehyde for 10 h. Six pre-established points were measured in the prototyped surgical guides, before and after sterilization, using a digital caliper rule. The comparisons were made using orthogonal contrasts using the linear model of mixed effects (random and fixed). RESULTS: there are no significant differences between autoclave and glutaraldehyde 2% (p>0.05) there are significant differences after autoclave sterilization (p<0.05) and there are not significant differences after 2% glutaraldehyde sterilization (p>0.05). CONCLUSION: autoclave promoted dimensional alteration of the prototyped surgical guides, and the chemical sterilization by glutaraldehyde 2% did not cause dimensional alteration of the prototype surgical guides, being a favorable choice for sterilization. CLINICAL SIGNIFICANCE: the sterilization of surgical guides can be performed through the chemical process with 2% glutaraldehyde without changing the linear precision of the prototype surgical guides.

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).

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)

Adhesive systems effect over bond strength of resin-infiltrated and de/remineralized enamel.

Background: The purpose of this study was to evaluate the effect of different bonding agents on bond-strength to demineralized enamel after remineralizing treatments and resin infiltration. Methods: Buccal enamel of 120 bovine incisors was polished and then were divided into five experimental groups: SE (sound enamel); DE (demineralized enamel); AS (demineralized enamel immersed in artificial saliva for eight weeks); NaF (demineralized enamel treated with 0.05% sodium fluoride solution (one minute) for eight weeks); Ic (demineralized enamel infiltrated with a low-viscosity resin (Icon-DGM). These groups were subdivided according to adhesive system used: self-etching adhesive Adper Easy One (3M/ESPE) and etch-and-rinse adhesive Single Bond (3M/ESPE). The composite resin blocks were fabricated using a Teflon matrix. A thermomechanical cycling machine was used to carry out the artificial aging of the specimens and thus were sectioned into sticks. The microtensile tests were performed using a universal testing machine at a cross-head speed of 1 mm/min. Data (in MPa) were subjected to two-way ANOVA and Tukey's tests (5%). Results: Significant differences were found for both factors tested and interactions (p<0.05). Tukey's test results of µTBS (mean ± SD) were: etch-and-rinse SE (28.79±3.93); DE (30.41±7.22); AS (29.03±3.33); NaF (29.81±4.06)a; Ic (29.47±5.5);  and self-etching SE (30.37±6.96); DE (14.62±4.47); AS (9.79±2.32); NaF (9.36±2.31); Ic (30.78±8.68).   Conclusions: Resin infiltration did not affect the bond strength of demineralized enamel for both adhesive systems tested. For etch-and-rinse adhesive, no differences were observed for the tested groups. For self-etching adhesive, only the resin-infiltrated group showed similar bond strength to sound enamel. Both etch-and-rinse and self-etching adhesive systems can be used in resin-infiltrated enamel, if a composite restoration needs to be further performed. In enamel that has undergone the de/remineralization process, the use of a total-etch adhesive might be preferable for the restorative procedure.

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.

Effect of Lining Materials on Shear Bond Strength for Composite Restorations In Vitro.

This study evaluated the influence of liner agents placed under resin composite restorations on shear bond strength (SBS) to dentin. A total of 40 extracted bovine incisors were used. Enamel surfaces were ground to expose a flat dentin area of 7 mm in diameter. Teeth were divided into four groups according to tested liners: Group 1 (control) used no liner; Group 2 used a resin-modified glass-ionomer cement liner (Vitrebond Plus, 3M ESPE); Group 3 used a light-activated calcium hydroxide resin liner (Ultra-Blend Plus, Ultradent); and Group 4 used a polyacrylic acid surface treatment + conventional glass-ionomer cement liner (Vidrion F, SSWhite). All groups were subjected to bonding procedures with Single Bond (3M ESPE) and 4-mm-thick buildups of resin composite were fabricated. Artificial aging was performed, and the specimens were submitted to mechanical shear testing. One-way analysis of variance (ANOVA) revealed significant differences among liners (P = .00). Group 4 showed the highest SBS. Group 1 showed significantly higher mean SBS compared with Group 3. Results showed that SBS is improved when using polyacrylic acid surface treatment + conventional glass-ionomer cement and decreased when using light-activated calcium hydroxide when compared with no liner. Polyacrylic acid surface treatment + conventional glass-ionomer cement as a liner placed under adhesion surface can improve the shear bond strength between dentin and resin, while light-activated calcium hydroxide resin should be used restrictedly in very deep cavities, because they may reduce the bond strength of the restoration submitted to masticatory forces and temperature changes in the oral environment.

Influência da clorexidina na resistência de união longitudinal à dentina: estudo in vitro / Influence of chlorhexidine on longitudinal bond strength to dentin: in vitro study

Objetivo: Este estudo avaliou o efeito da solução de gluconato de clorexidina 0,2% (CHX) usado como primer terapêutico sobre a resistência de união longitudinal de adesivo convencional a dentina. Material e Métodos: dentes bovinos foram desgastados para obter uma área de dentina, e foram divididos em 2 grupos: Grupo C (Controle) - ácido fosfórico à 37%) + 0,2% CHX por 30s + Single Bond. Blocos de resina composta form fabricados e armazenados por 24 h e 6 meses, seccionados e submetidos ao teste de resistência a microtração. Os resultados foram analisados por ANOVA dois-fatores seguido pelo teste de Tukey. Resultados: Valores de média (±Desvio-padrão) (MPa): Grupo CHX/24h - 41,8(±2,62)A; Grupo C/24h - 40,8(±3,35)AB; Grupo CHX/6 meses ­ 36,4(±3,52)B; Grupo CHX/6 meses - 26,1(±1,54) C. Resultados: Valores de média (±Desvio-padrão) (MPa): CHX (24 h) ­ 41,76 (±2,62)a; C (24h) ­ 40,81 (±3,35)ab; GT (24h): 37,38(2,98)abc; CHX (6 meses) ­ 36,04 (±3,52) bcd; EGCG (24h) ­ 35,91 (±4,82)cd; EGCG (6 meses) ­ 35,75 (±4,44)cd; GT (6 meses) ­ 31,95 (±3,40)de; C (6 meses): 30,05 (±1,54)e. Conclusão: CHX aumentou a resistência de união imediata da interface dentina-resina e significantemente reduziu a perda de resistência de união após 6 meses de armazenagem em água quando comparado ao grupo controle.(AU)

Objective: This study evaluated the effect of 0.2% chlorhexidine gluconate solution used as an therapeutic primer on the long-term bond strength of etch-and-rinse adhesive to dentin. Material and Methods: Bovine incisors were worn to expose an area of dentin and were divided into 2 groups: Group C (Control) - acid etching with 37% phosphoric acid + Single Bond; Group CHX (0.2% CHX) - acid etching with 37% phosphoric acid + 0.2% CHX for 30 s + Single Bond. Blocks of composite were fabricated and stored for 24 h or 6 months, sectioned into beams and submitted to microtensile tests. Results were analyzed by two-way ANOVA and Tukey tests. Results: Mean (±SD) values (in MPa) were as follow: Group CHX/24h - 41.8(±2.62)A; Group C/24h - 40.8(±3.35)AB; Group CHX/6 months ­ 36.4(±3.52)B; Group CHX/6 months - 26.1(±1.54)C. Conclusion: CHX improve the imediatte bond strength of resin-dentin and significantly lowered the loss of bond strength after 6 months water storage as seen in the control bonds.(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.

Zn-doped etch-and-rinse model dentin adhesives: Dentin bond integrity, biocompatibility, and properties.

OBJECTIVE: This study assessed a 6 month resin/dentin bond's durability and cytotoxic effect of Zn-doped model dentin adhesives. The mechanical and physicochemical properties were also tested. METHODS: A model etch-and-rinse single-bottle adhesive was formulated (55wt.% Bis-GMA, 45wt.% HEMA, 0.5wt.% CQ, 0.5wt.% DMAEMA) and Zinc methacrylate (Zn-Mt) or ZnO nanoparticles (ZnOn) were added to the model's adhesive, resulting in three groups: Group Control (control model adhesive); Group Zn-Mt (1wt.% Zn-Mt incorporated to adhesive) and Group ZnOn (1wt.% ZnOn incorporated to adhesive). The microtensile bond strength (mTBS) was assessed after 24h or 6 months in water storage. Mechanical properties (diametral tensile strength/DTS, flexural strength/FS, flexural modulus/FM, resilience modulus/RM, and compressive strength/CS) and physicochemical properties (polymerization shrinkage/PS, contact angle/CA, water sorption/WS, and water solubility/WS) were also tested. Cytotoxicity was evaluated with SRB biochemical assay. RESULTS: No significant difference in the DTS, FS, FM, CS, CA, WS, and WS were found when 1% of ZnOn or Zn-Mt was added to the model dentin adhesive. Group Zn-Mt decreased the RM of adhesive. Groups Zn-Mt and ZnOn decreased the PS of adhesives. Group ZnOn reduced the cytotoxicity of adhesive. Group ZnOn preserved mTBS after 6 months storage without degradation areas as seen by SEM analysis. SIGNIFICANCE: The 1wt.% ZnOn may preserve the integrity of the hybrid layer and may reduce cytotoxicity and polymerization shrinkage of model dentin adhesive. The addition of Zn-Mt to the adhesive had no beneficial effects.

Effect of chlorhexidine, green tea and egcg as therapeutic primers to increase the durability of resin-dentin bond / Efeito da clorexidina, do chá verde e do EGCG como primers terapêuticos para aumentar a durabilidade da adesão resinadentina

Objetivo: este estudo avaliou o efeito da solução de gluconato de clorexidina 0,2% (CHX), do chá verde e do componente ativo epigallocatequina 3-gallato (gel de EGCG) usados como primers terapêuticos sobre a resistência de união longitudinal de adesivo convencional a dentina. Material e Métodos: oitenta dentes bovinos foram desgastados para obter uma área de dentina plana, que foi condicionada (ácido fosfórico à 37%) seguida de lavagem. Os dentes foram divididos em 4 grupos (n- 20): Grupo C (Controle) - Single Bond; Grupo CHX – 0,2% CHX por 30s + Single Bond; Grupo EGCG - gel de EGCG 10µM por 30s + Single Bond; Group GT – chá verde aquoso por 30s + Single Bond. Blocos de resina composta form fabricados e armazenados por 24 h e 6 meses, seccionados e submetidos ao teste de resistência a microtração. Os resultados foram analisados por ANOVA dois-fatores seguido pelo teste de Tukey. Resultados: Valores de média (±Desvio-padrão) (MPa): CHX (24 h) – 41,76 (±2,62)a; C (24 h) – 40,81 (±3,35)ab; GT (24h): 37,38(2,98)abc; CHX (6 meses) – 36,04 (±3,52) bcd; EGCG (24h) – 35,91 (±4,82)cd; EGCG (6 meses) – 35,75 (±4,44)cd; GT (6 meses) – 31,95 (±3,40)de; C (6 meses): 30,05 (±1,54)e. Conclusão: O gel de EGCG produziu uma interface adesiva dentina-resina que não alterou os valores de resistência de união após 6 meses de armazenagem em água, mas reduziu a resistência de união para o tempo de 24 h quando comparado com os grupos Controle e CHX.

Objective: This study evaluated the effect of 0.2% chlorhexidine gluconate solution (CHX), green tea and active epigallocatechin-gallate (EGCG) used as therapeutic primers on the longterm bond strength of etch-and-rinse adhesive to dentin. Material and Methods: Eighty bovine incisors were worn to expose an area of dentin, that were acid-etched (37% phosphoric acid) and rinsed. The teeth were divided into 4 groups (n = 20): Group C (Control) - Single Bond; Group CHX - 0.2% CHX for 30s + Single Bond; Group EGCG - active EGCG gel at 10 µM for 30 s + Single Bond; Group GT - aqueous green tea for 30s + Single Bond. Blocks of composite were fabricated and stored for 24 h or 6 months, sectioned into beams and submitted to microtensile tests. Results were analyzed by two-way ANOVA and Tukey’s test (5%). Results: Mean (±SD) values (in MPa) were as follow: CHX (24 h) – 41.76 (±2.62); C (24 h) - 40.81 (±3.35); GT (24 h): 37.38(2.98); CHX (6 months) - 36.04 (±3.52); EGCG (24h) - 35.91 (±4.82); EGCG (6 months) - 35.75 (±4.44); GT (6 months) - 31.95 (±3.40); C (6 months): 30.05 (±1.54). Conclusion: EGCG produced resin-dentin bonds that did not change after 6 months water storage but it decreased the immediate bond strength when compared to control and chlorhexidine groups

Nd:YAG laser influence on the hybridization quality, employing total-etching or self-etching adhesives: sem analysis / Influência do laser de Nd:YAG na qualidade de hibridização empregando-se sistemas adesivos de condicionamento total ou autocondicionante: análise em MEV

A aplicação do laser de Nd:YAG na dentina sobre o sistema adesivo não polimerizado pode influenciar a qualidade da camada híbrida formada. Objetivo: o objetivo deste estudo foi verificar através da análise em microscopia eletrônica de varredura (MEV) a influência do laser de Nd:YAG na qualidade de hibridização, usando-se o sistema adesivo de condicionamento total Adper Single Bond 2 (SB) ou o auto-condicionante Clearfil SE Bond(CSEB). Material e Métodos: nove incisivos foram seccionados resultando em 36 espécimens que foram divididos em 2 grupos (n=18): Group SB- adesivo de condicionamento total SB; Group CSEB-adesivo auto-condicionante CSEB. Previamente à aplicação dos sistemas adesivos, cada grupo foi dividido em 3 subgrupos de acordo com os parâmetros do laser de Nd:YAG (n=6): Subgroup controle- polimerização do adesivo por 10s (600 mW/cm2); Subgrupo Laser 60 mJ: laser de Nd:YAG (60 mJ, 10Hz, 74,72 J/cm2) com irradiação sobre a dentina impregnada com sistema adesivo não polimerizado + polimerização por 10s (600 mW/cm2); Subgrupo Laser 140 mJ: laser de Nd:YAG (140 mJ, 10Hz, 174,34 J/cm2)com irradiação sobre a dentina impregnada com sistema adesivo não polimerizado + polimerização por 10s (600 mW/cm2). Todos os espécimens foram restaurados com resina composta (Filtek Z350 - 3M). A espessura, a presença de falhas (fendas/ porosidades) e características dos tags/microtags na camada híbrida foram analisados em MEV. Os resultados foram submetidos aos testes estatísticos

Background: The application of Nd:YAG laser on dentin with the non polymerized adhesive can influenced the quality of hybrid layer formed. Objectives: The aim of this study was to assess through analysis by scanning electronic microscopy (SEM), the Nd:YAG laser influence on the hybridization quality, using totaletching Single Bond (SB) or self-etching Clearfil SE Bond (CSEB) adhesives. Material and Methods: Nine bovine incisors were sectioned and resulted in 36 specimens and divided into 2 groups (n=18): Group SB – SB total-etching adhesive; Group CSEB - CSEB selfetching adhesive. Before the polymerization of these adhesives, each group was divided in 3 subgroups, according to the laser parameters (n=6): Subgroup Control - polymerization for 10 s (600 mW/cm2);Subgroup Laser 60mJ: Nd:YAG laser (60mJ, 10Hz, 74.72J/cm2) irradiation on dentin impregnated with non polymerized adhesives + polymerization for 10 s (600 mW/cm2); Subgroup Laser 140mJ - Nd:YAG laser (140mJ, 10Hz, 174.34J /cm2) irradiation ondentin impregnated with non polymerized adhesives + polymerization for 10s (600 mW/cm2)....

Can Nd: YAG laser irradiated on dentin with non-polymerized adhesives influence the durability of bond strength and micromorfology of hybrid layer? / Pode o laser Nd:YAG irradiado sobre a dentina impregnada com adesivos não polimerizados influenciar na durabilidade da resistência de união e micromorfologia da camada híbrida?

Objetivo: Este estudo avaliou a durabilidade da resistência de união à dentina utilizando adesivo convencional (Single Bond/SB) e auto condicionante(Clearfil SE Bond/CSEB) associados a irradiação do Nd: YAG laser sobre os adesivos não-polimerizados. Esse estudo também avaliou mudanças micromorfológicas da camada híbrida após armazenagem por 12 meses em água. Material e Métodos: incisivos bovinos foram desgastados para expor uma área de dentina e foram divididos em 4 grupos (n = 15): Grupo 1 (controle) - SB + fotopolimerização; Grupo 2 (Controle) - CSEB + fotopolimerização; Grupo 3 (experimental/laser) - SB + laser Nd:YAG (149,28 J/cm2) + fotopolimerização; Grupo 4 (experimental/ laser) - CSEB + laser Nd:YAG (149,28 J/cm2) + fotopolimerização. Os dentes foram restaurados com resina composta e armazenados por 24 h ou 12 meses(12 m), seccionados em palitos e submetidos s a testes de resistência de união à microtração. Dois dentes de cada grupo (n = 2) foram preparados para análise em MEV. Os resultados foram analisados por ANOVA três-fatores (Adesivo, Técnica e Armazenamento) e teste de Tukey (0,05). Resultados: Resultados para interação Adesivo X Técnica X Armazenamento (valores médios MPa): SB/Controle/24 h = 34,05 (± 6,14) a; CSEB/Controle/24 h = 32,12 (± 5,26)a; SB/laser/24 h = 30,54 (± 5,94) a; CSEB/laser/24 h = 29,45 (± 5,11) a; SB/Controle/12 m = 29,36 (± 5,57) a; CSEB/Controle/12 m = 29,09 8,84) a; SB/laser/12 m = 22,06 (± 3,77) b; CSEB/ laser/12 m = 13,35 (± 3,35) c. Conclusão: Análise de MEV mostrou áreas evidentes de alterações micromorfológicas em amostras irradiadas após 12 meses de armazenamento de água com a degradação acelerada da camada híbrida....

Objective: This study evaluated the durability of bond strength to dentin using total-etch (Single Bond /SB) and self-etch (Clearfil SE Bond/CSEB adhesives associated with Nd:YAG laser irradiation through the unpolymerized adhesives. Also, this study evaluated micromorfological chances in hybrid layer after 12 months water storage.Material and Methods: Bovine incisors were worn to expose a dentin area and were divided into 4 groups (n = 15): Group 1 (Control) – SB + photopolymerization; Group 2 (Control) – CSEB + photopolymerization; Group 3 (experimental/laser) - SB + Nd:YAG laser (149.28 J/cm2) + photopolymerization; Group 4 (experimental/laser) – CSEB + Nd:YAG (149.28 J/cm2) + photopolymerization. Composite blocks were fabricated; intact teeth were stored for 24 h or12 months (12 m), sectioned into beams and submitted to microtensile bond strength tests Two teeth from each group (n = 2) were prepared forSEM analysis. Results: For interaction Adhesive X Technique X Storage time the mean values (MPa) were: SB/Control/24h = 34.05(± 6.14)a; CSEB/Control/24h = 32.12(± 5.26)a; SB/laser/24h = 30.54(±5.94)a; CSEB/laser/24 h = 29.45(±5.11)a; SB/Control/12 m = 29.36(± 5.57)a; CSEB/Control/12 m = 29.09(± 8.84)a; SB/laser/12m= 22.06(±3.77)b; CSEB/laser/12 m = 13.35(±3.35)c. Conclusions: SEM showed evident areas o micromorphological alterations on lased samples after 12 months water storage with accelerated degradation of the hybrid layer. Bond strength decreased when dentin irradiated with the Nd:YAG laser through unpolymerized adhesives was storedin water for 12 months.

CVD tip or diamond bur: can they influence the bondstrength of a total-etch adhesive to dentin? / Pontas diamantadas e CVD: podem influenciar na força de união de um adesivo convencional à dentina?

Evaluate the microtensile bond strength of a total-etch adhesive to dentin, using a CVD tipor diamond bur for dentin preparation and varying the etching time. Material and Methods: The dentin from the buccal surface of sixty bovine teeth was exposed and prepared using two different methods(n = 30): Group 1 (DB) – a diamond bur on a high-speed hand piece; and Group 2 (CVD) – a CVDtip on an ultrasonic hand piece. Each group used37% phosphoric acid and was divided into three subgroups, according to the etching time (n = 10):Subgroup 5s - 5 seconds; Subgroup 10s - 10 seconds; and Subgroup 15s - 15 seconds. Teeth were restored with Single Bond adhesive and the composite resin Herculite Classic. The specimens were subjected to thermo mechanical wear (mechanical cycling/100.000 cycles, thermal cycling/1.000cycles). Stick-like specimens were obtained and submitted to a microtensile test in a universal testing machine. Data (MPa) were analyzed by two-way ANOVA (Surface treatment X Etching time) andTukey’s test (5%). Results and Conclusion: Surface treatment with CVD tips (27.70 ± 4.04a) produced significantly higher bond strength values compared to diamond burs (23.96 ± 5.83b), and 5 s etching time on dentin produced similar bond strength values when compared to 10 and 15 s etching times...

Objetivo: avaliar a força de união de um adesivo convencional à dentina, usando pontas diamantadas e pontas CVD para preparo dentinário e variando o tempo de condicionamento ácido a dentina. Material e Métodos: A dentina da superfície vestibular de 60 dentes bovinos foi exposta e preparada usando dois diferentes métodos (n=30): Grupo 1 (DB) – ponta diamantada tradicional para alta rotação; e Grupo 2(CVD) – ponta CVD montada em ultrassom. Cada grupo foi dividido em três subgrupos, de acordo com o tempo de condicionamento ácido (n=10): Subgrupo 5s - 5 segundos; Subgrupo 10s - 10 segundos; e Subgrupo 15s- 15 segundos. Os dentes foram restaurados com adesivo convencional Single Bond e resina composta Herculite Classic. As restaurações foram submetidas à ciclagemtermo-mecânica (ciclagem mecânica/100.000 ciclos,ciclagem térmica/1.000 ciclos). Palitos foram obtidos e submetidos ao teste de microtração na máquina de ensaios universal. Os dados (MPa) foram analisados por ANOVA dois-fatores (Tratamento de superfície X condicionamento) e teste de Tukey (5%). Resultado e Conclusão: O tratamento de superfície com pontas CVD (27.70 ± 4.04a) resultaram em valores de adesão significantemente maiores quando comparados com as pontas diamantadas (23.96 ± 5.83b), e 5 segundos de condicionamento ácido sobre a dentina produziu valores similares de adesão quando comparado aos tempos de 10 e 15 segundos de condicionamento...

Clinical performance of topical sodium fluoride when supplementing carbamide peroxide at-home bleaching gel.

This clinical study evaluated the use of 0.11% topical sodium fluoride (SF) desensitizing agent to treat tooth sensitivity during a nightguard tooth whitening procedure. Thirty-two subjects bleached their teeth with 10% carbamide peroxide (CP) gel using an at-home bleaching technique with custom trays. During bleaching treatment, subjects were divided into 2 groups (n = 16). The subjects in Group 1 received a topical gel containing 0.11% SF; the subjects in Group 2 received a placebo gel (PG). Each subject was instructed to place the gel in his/her bleaching tray for 30 min every day following bleaching treatment. Results showed the use of SF did not affect the whitening efficacy of the 10% CP gel. Subjects who received the PG had significantly higher tooth sensitivity when compared with subjects who received SF (P < 0.00). The use of daily 0.11% SF after 10% CP bleaching gel reduced tooth sensitivity during the bleaching treatment.

Effect of Nd:YAG laser on the solvent evaporation of adhesive systems.

OBJECTIVE: This study evaluated the influence of Nd:YAG laser on the evaporation degree (ED) of the solvent components in total-etch and self-etch adhesives. MATERIALS AND METHODS: The ED of Gluma Comfort Bond (Heraeus-Kulzer) one-step self-etch adhesive, and Adper Single Bond 2 (3M ESPE), and XP Bond (Dentsply) total-etch adhesives was determined by weight alterations using two techniques: Control--spontaneous evaporation of the solvent for 5 min; Experimental--Nd:YAG laser irradiation for 1 min, followed by spontaneous evaporation for 4 min. The weight loss due to evaporation of the volatile components was measured at baseline and after 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, 90 s, 100 s, 110 s, 2 min, 3 min, 4 min, and 5 min. RESULTS: Evaporation of solvent components significantly increased with Nd:YAG laser irradiation for all adhesives investigated. Gluma Comfort Bond showed significantly higher evaporation of solvent components than Adper Single Bond 2 and XP Bond. All the adhesives lost weight quickly during the first min of Nd:YAG laser irradiation. CONCLUSION: The application of Nd:YAG laser on adhesives before light curing had a significant effect on the evaporation of the solvent components, and the ED of Gluma Comfort Bond one-step self-etch adhesive was significantly higher than with Adper Single Bond 2 and XP Bond total-etch adhesives. CLINICAL RELEVANCE: The use of the Nd:YAG laser on the uncured adhesive technique can promote a greater ED of solvents, optimizing the longevity of the adhesive restorations.

Mechanical properties of the bond interface associated with ND: YAG laser / Propriedades mecanicas da interface adesiva associada ao laser de ND: YAG

This study evaluated the hardness and modulus of elasticity of the dentin bond interface using total-etch(Single Bond /SB) and self-etch (Clearfil SE Bond/CSEB) adhesives associated with Nd:YAG Laser irradiation through the unpolymerized adhesives. Material and Methods: The occlusal surfaces of 12 human third molars were ground until superficial dentin was exposed. A standardized circular cavity was performed on the occlusal surface. Specimens were sectioned in the mesio-distal direction, and the 24 hemi-crowns were divided into four groups: Group SB/Control - SB + polymerization; GroupSB/Laser - SB + Nd:YAG laser (174.16J/cm2/60s/noncontact)+ polymerization; Group CSEB/Control – CSEB +polymerization; Group CSEB/Laser - CSEB + Nd:YAG laser(174.16J/cm2/cm2/60s/non-contact) + polymerization. Composite were placed in the cavities and polymerized. The specimens were immersed in distilled water and stored in an oven at 37ºC for 24h and then submitted to nanoindentation in a Nano Indenter® XP appliance. Results: The results were submitted to ANOVA, Tukey’stest and Student’s-t test (p < 0.05). Conclusion: It was concluded that the application of the Nd:YAG laser inboth adhesive systems did not changed the hybrid layer hardness; however, it increases the modulus of elasticityin the hybrid layer for both adhesives tested and it may bepreserves the integrity of the adhesive interface and its durability. Clinical relevance: The application of Nd:YA Glaser prior to photopolymerization of adhesive systems can increase the modulus of elasticity in the hybrid layerand may contribute to stress distribution in the adhesive interface during the polymerization preserving the integrity of the adhesive interface and its durability...

este estudo avaliou a dureza e o módulo de elasticidade da interface adesiva a dentina usando adesivo convencional (Sinngle Bond /SB) e adesivo autocondicionante (Clearfil SE Bond/CSEB) associados com irradiação do Laser Nd:YAH sobre os adesivos não polimerizados. Material e Métodos: As superfícies oclusais de 12 terceiros molares humanos foram desgastadas ate exposição de dentina superficial plana. Cavidades circulares padronizadas foram realizadas na superficie oclusal. Os espécimes foram seccionados no sentido mesio-distal, e as 24 hemicoroas foram divididas em quatro grupos: Grupo SB/Controle - SB + fotopolimerização; Grupo SB/Laser- SB + Laser Nd:YAG (174,16J/cm2/60s/não-contato)+ fotopolimerização; Grupo CSEB/Controle – CSEB +fotopolimerização; Grupo CSEB/Laser - CSEB + LaserNd:YAG (174.16J/cm2/cm2/60s/ não-contato) +fotopolimerização. Restaurações de resina composta foram realizadas nas cavidades e fotopolimerizadas. Os espécimes foram armazenados em água destilada a 37 ºC por 24 h e submetidas a nanoindentação no aparelho Nano Indenter® XP. Resultados: Os resultados foram submetidos ao ANOVA, seguidos dos testes de Tukey e T-Student (p < 0,05). Conclusão:Foi concluído que a aplicação do Laser de Nd:YAG nos adesivos não alterou a dureza da camada híbrida;entretanto, aumentou o módulo de elasticidade de ambos os adesivos testados e talvez preserve a integridade da interface adesiva e sua durabilidade...

What is the best protocol for bonding resin-modified glass ionomer cement to composite resin? / Qual o melhor protocolo de união entre cimento de ionomero de vidro resina-modificado e resina composta?

Objetivo: O objetivo desse estudo foi avaliar a resistência de união entre cimento de ionômero de vidro resina-modificado (CIVRM) e resina composta, considerando a utilização de sistemas adesivos de condicionamento acido total e autocondicionantes. Material e Métodos: Confeccionaram-se 60 blocos de CIVRM (Riva, SDI) de dimensões de 4x4 mm. Sobre os blocos, variou-se o protocolo de aplicação de diferentes sistemas adesivos (n = 10): Grupo 1 (Controle) – sem aplicação de adesivo; Grupo 2 – ácido fosfórico 37% + Single Bond; Grupo 3 - Single; Grupo 4 - Bond do Scotch Bond MultiPurpose Plus Adhesive; Grupo 5 - Clearfil SE Bond; Grupo 6: Obtibond All-in-One. Em seguida, foram confeccionados blocos de resina composta (Venus, Heraeus Kulzer) de dimensões de 4x4X4 mm. Foram realizados cortes nos espécimes para obtenção de amostras com área coesiva de 1 mm2, que foram submetidas ao teste de microtração em máquina de ensaios universal. Os dados foram submetidos aos testes ANOVA e Tukey. Resultados: ANOVA apresentou um valor de p < 0.05, o que indicou diferenças significantes entre os grupos (em Mpa): Grupo 2 – 32,83 a; Grupo 5 – 31,2 a; Grupo 3 – 25,15 ab; Grupo 6 – 22,92 ab; Grupo 4 22,15 ab; Grupo 1 – 13,84 b. Conclusão: os protocolos condicionamento ácido + Single Bond ou Clearfil SE Bond aumentaram resistência de união entre o CIVRM e a resina composta. A presença de uma camada de adesivo entre os dois materiais tende a melhorar a união entre CIVRM e resina composta.

Objective: The objective of this study was to evaluate the bond strength of resin-modified glass ionomer cement (RMGIC) to composite resin considering the use of conventional and self-etching adhesive systems. Material and Methods: 60 RMGIC blocks (Riva, SDI) measuring 4 x 4 x 4 mm. were constructed. On the blocks, the application of different protocols of adhesive systems (n = 10) was carried out: Group 1 (Control) - without application of adhesive agent; Group 2 - 37% phosphoric acid + conventional adhesive agent Single Bond 2; Group 3 - conventional adhesive agent Single Bond 2; Group 4 – conventional adhesive agent Scotch Bond Multi-Purpose; Group 5 - self-etching adhesive Clearfil SE Bond; Group 6: self-etching adhesive Optibond Allin-One. Next, resin composite blocks measuring 4 x 4 x 4 mm were constructed (Venus, Heraeus Kulzer). The specimens were cut to obtain sticks which were submitted to microtensile bond strength test in a universal testing machine. The data were submitted to ANOVA and Tukey test (5%). Results: ANOVA showed a value of p < 0.05, which indicated significant differences between the groups (in Mpa): Group 2 - 32.83; Group 5 - 31.2; Group 3 - 25,15b; Group 6 - 22.92; Group 4 - 22.15; Group 1 - 13.84. The analysis of fracture mode demonstrated that there was a predominance of adhesive and mixed fractures for all groups. Conclusion: The protocols of acid etching + conventional adhesive system Single Bond 2 (Group 2) or self-etching adhesive system Clearfil SE Bond (Group 5) increased the bond strength of RMGIC to the composite resin. The presence of an adhesive layer between the two materials tended to improve the bonding of RMGIC to composite resin