Effect of photobiomodulation therapy on pain perception during anesthetic puncture of dental local anesthesia: A systematic review.

BACKGROUND: Local anesthetic puncture is often related to the experience of pain. This study aimed to systematically analyze the literature on changes in pain perception during the anesthetic puncture of dental local anesthesia after Photobiomodulation Therapy (PBMT). MATERIAL AND METHODS: An electronic search was performed in eight primary databases (Embase, LILACS, BBO, LIVIVO, MedLine via PubMed, SciELO, Scopus, and Web of Science) and three additional ones (EASY, Google Scholar, and OATD) to partially capture the "gray literature". The PICO strategy was used to identify randomized clinical trials evaluating the analgesic effect of PBMT in the anesthetic puncture site of dental local anesthesia compared to placebo or control groups, without restrictions on publication language and year. Two reviewers extracted the data and assessed the individual risk of bias of the eligible studies using the Cochrane Collaboration Risk of Bias Tool version 2.0. RESULTS: The electronic search found 3,485 records, of which eight met the eligibility criteria and were included in the qualitative synthesis. The studies were published from 2011 to 2022. None of the included studies had a low risk of bias. PBMT groups showed no significant difference in pain scores compared to placebo and control groups of most studies. CONCLUSION: Based on a low to very low certainty of evidence, PBMT seems to have no effect on pain perception during anesthetic puncture in patients undergoing dental local anesthesia.

Efficacy, safety, and potential industry bias in using deoxycholic acid for submental fat reduction ‒ A systematic review and meta-analysis of randomized clinical trials.

Lipolytic substance injections to reduce localized fat have been extensively used because it is a low-invasive method. This review aimed to evaluate the efficacy and safety of deoxycholic acid in submental fat reduction compared to a placebo and investigate the potential industry sponsorship bias in the results of randomized clinical trials on this topic. Ten electronic databases were extensively searched for randomized clinical trials without restriction on language and year of publication. Two reviewers extracted the data and assessed the individual risk of bias in the studies with the RoB 2.0 tool. The industry sponsorship bias was evaluated according to citations in the articles regarding industry funding/sponsorship throughout the texts. Fixed and random effects meta-analyses were performed, and the results were reported in Risk Ratio (RR) at a 95% Confidence Interval (95% CI). The initial search provided 5756 results, of which only five were included. Only two studies had a low risk of bias. All studies showed a potential industry bias. The meta-analysis showed that patients treated with deoxycholic acid had significant positive results for all efficacy outcomes and a higher risk of fibrosis, pain, erythema, numbness, swelling, edema, pruritus, nodules, headache, and paresthesia. The low to moderate certainty of evidence found allows concluding that deoxycholic acid is effective in submental fat reduction, causing well-tolerated adverse effects. However, all eligible studies showed a potential industry bias.

Analysis of biofilm formation by Candida albicans in different types of orthodontic fixed appliances and devices / Análise da formação de biofilme por Candida albicans em diferentes tipos de aparelhos e dispositivos ortodônticos fixos

Objective: in this study, biofilm formation by Candida albicans in fixed orthodontic appliances was evaluated. Material and Methods: a total of 300 conventional metal brackets (MC), ceramic (CB), self-ligation (SLB), nickel-titanium (NiTi), and nickel-chromium (NiCr) wires, and ligatures types were organized into thirty groups (n=10). To induce biofilm formation, brackets, wires, and ligatures were joined, sterilized, placed in 24-well plates, contaminated with standardized suspensions of C. albicans (107 cells/mL), and incubated at 37 °C for 48 h with shaking. The biofilms formed were detached using an ultrasonic homogenizer, and suspensions were serially diluted and plated on Sabouraud dextrose agar to determine colony-forming units per mL. Scanning electron microscopy was performed before and after the biofilm formation. Results: lower amount of biofilm formation was observed in the MC group than in the CB and SLB groups (p<0.0001). SLB and CB showed similar biofilm formation rates (p=0.855). In general, the cross-sectional wires .018"x.025" showed higher biofilm formation when associated with the three types of brackets. When brackets, wires, and ligatures were associated, the sets with NiCr wires and SSL ligatures with MC brackets (p=0.0008) and CB (p=0.0003) showed higher biofilm formation. Conclusion: thus, brackets of MC with NiTi and NiCr wires showed lower biofilm formation, regardless of the ligature and cross-sectional or gauge of the wire and, MC and CB brackets with NiCr wires and SSL ligatures were more likely to accumulate biofilms (AU)

Objetivo: neste estudo, a formação de biofilme por Candida albicans em aparelhos ortodônticos fixos foi avaliada. Material e Métodos: um total de 300 bráquetes metálicos convencionais (MC), cerâmicos (CB), autoligados (SLB), com fios de níquel-titânio (NiTi) e níquel-cromo (NiCr) e tipos de ligaduras foram organizados em trinta grupos (n=10). Bráquetes, fios e ligaduras foram unidos, esterilizados, colocados em placas de 24 poços, contaminados com suspensões padronizadas de C. albicans (107 células/mL) e incubados a 37°C por 48 h para a formação de biofilmes. Os biofilmes formados foram rompidos por meio de um homogeneizador ultrassônico e suspensões foram diluídas e semeadas em ágar Sabouraud-dextrose para determinar as unidades formadoras de colônias por mL. A microscopia eletrônica de varredura foi realizada antes e após a formação do biofilme. Resultados: foi observada menor formação de biofilme no grupo MC em comparação aos grupos CB e SLB (p<0,0001). A formação de biofilme foi semelhante nos grupos SLB e CB (p=0,855). Em geral, os fios de seção transversal .018"x.025" apresentaram maior formação de biofilme quando associados aos três tipos de bráquetes. Os conjuntos com fios de NiCr e ligaduras SSL com bráquetes MC (p=0,0008) e CB (p=0,0003) apresentaram maior formação de biofilme. Conclusão: bráquetes MC com fios de NiTi e NiCr apresentaram menor formação de biofilme, independente da ligadura e secção transversal ou bitola do fio e, braquetes MC e CB com fios de NiCr e ligaduras SSL foram mais propensos a acumular biofilmes.(AU)

Efficacy, safety, and potential industry bias in using deoxycholic acid for submental fat reduction - A systematic review and meta-analysis of randomized clinical trials

Abstract Lipolytic substance injections to reduce localized fat have been extensively used because it is a low-invasive method. This review aimed to evaluate the efficacy and safety of deoxycholic acid in submental fat reduction compared to a placebo and investigate the potential industry sponsorship bias in the results of randomized clinical trials on this topic. Ten electronic databases were extensively searched for randomized clinical trials without restriction on language and year of publication. Two reviewers extracted the data and assessed the individual risk of bias in the studies with the RoB 2.0 tool. The industry sponsorship bias was evaluated according to citations in the articles regarding industry funding/sponsorship throughout the texts. Fixed and random effects meta-analyses were performed, and the results were reported in Risk Ratio (RR) at a 95% Confidence Interval (95% CI). The initial search provided 5756 results, of which only five were included. Only two studies had a low risk of bias. All studies showed a potential industry bias. The meta-analysis showed that patients treated with deoxycholic acid had significant positive results for all efficacy outcomes and a higher risk of fibrosis, pain, erythema, numbness, swelling, edema, pruritus, nodules, headache, and paresthesia. The low to moderate certainty of evidence found allows concluding that deoxycholic acid is effective in submental fat reduction, causing well-tolerated adverse effects. However, all eligible studies showed a potential industry bias.

The endocannabinoid system and orofacial pains: updates and perspectives / O sistema endocanabinoide e as dores orofaciais: atualidades e perspectivas

ABSTRACT BACKGROUND AND OBJECTIVES: Since the relatively recent discovery of the endocannabinoid system (ECS) and its fundamental role in regulating other systems, the subject has aroused interest in all areas of health, including Dentistry. Among the possible uses and benefits of cannabinoids are their performance in pain and its predisposing or perpetuating factors, such as bruxism and sleep disorders. Although the literature is still scarce, the mechanisms of action and satisfactory results of cannabinoids and other cannabis derivatives in these situations already allow their safe prescription. The objective of this study was to verify the current evidence on the use of cannabis derivatives in orofacial pain (OFP), reviewing what is known, to date, about the ECS and the prospects for its use with support and criteria. CONTENTS: This research carried out a brief review of the cannabis plant history, addressing issues such as prejudice, prohibitions and interests, as well as its therapeutic use. Then, a review on ECS and its mechanisms of interest in OFP was presented. Next, the products derived from the plant and their effects, indications, contraindications, adverse effects, drug interactions, peculiarities and perspectives were discussed. CONCLUSION: The more knowledge is gained about the ECS and the therapeutic benefits of cannabis components and derivatives, the greater the conviction that a new therapeutic frontier has indeed emerged. The growing number of good outcomes, including cases of OFP, obtained through well-conducted studies, brings a mixture of satisfaction and excitement. No therapy will achieve good results if it does not start from an accurate diagnosis. Thus, it is of the utmost importance to know the ECS, the products and derivatives of the plant, the synthetic cannabinoids, their indications and effects. New studies are necessary and, at this moment, it can be said that the perspectives are very good and a new and challenging horizon is emerging.

RESUMO JUSTIFICATIVA E OBJETIVOS: Desde a descoberta relativamente recente do sistema endocanabinoide (SEC) e seu papel fundamental da regulação de outros sistemas, o assunto tem despertado interesse de todas as áreas da saúde, incluindo-se a Odontologia. Dentre as possíveis utilizações e benefícios dos canabinoides, está sua atuação na dor e seus fatores predisponentes ou perpetuadores, como o bruxismo e os distúrbios do sono. Embora a literatura seja ainda escassa, os mecanismos de ação e resultados satisfatórios dos canabinoides e demais derivados da cannabis nessas situações já permitem sua prescrição com segurança. O objetivo deste estudo foi verificar as atuais evidências sobre a utilização de derivados da cannabis nas dores orofaciais (DOFs), revisando o que se sabe, até o momento, sobre o SEC e as perspectivas de sua utilização com respaldo e critério. CONTEÚDO: Esta pesquisa realizou uma breve revisão da história da planta cannabis, abordando temas como preconceito, proibições e interesses, além de sua utilização terapêutica. Em seguida, foi apresentada uma revisão sobre o SEC e seus mecanismos de interesse na DOF. Na sequência, foram discutidos os produtos derivados da planta e seus efeitos, indicações, contraindicações, efeitos adversos, interações farmacológicas, peculiaridades e perspectivas. CONCLUSÃO: Quanto mais são adquiridos conhecimentos sobre o SEC e os benefícios terapêuticos dos componentes e derivados da cannabis, mais há um convencimento de que surgiu, de fato, uma nova fronteira terapêutica. O número crescente de bons desfechos, incluindo casos de DOF, obtidos através de estudos bem conduzidos, traz um misto de satisfação e empolgação. Nenhuma terapia obterá bons resultados se não partir de um diagnóstico preciso. Assim, é de suma importância que se conheça o SEC, os produtos e derivados da planta, os canabinoides sintéticos, suas indicações e efeitos. Novos estudos são necessários e, nesse momento, pode-se afirmar que as perspectivas são muito boas e um novo e desafiador horizonte está despontando.

Psychological Factors in Temporomandibular Disorders Patients during COVID-19 Pandemic: A Cross-Sectional Study

Abstract Objective: To assess the influence of the COVID-19 pandemic on levels of anxiety, stress, and orofacial pain in individuals with and without TMD. Material and Methods: In this cross-sectional study, the participants were divided into two groups (n=10, each) experimental group (EG) TMD patients and control group (CG), without TMD. The presence of TMD was confirmed using the RDC/TMD. The Beck Anxiety Scale (BAI), Perceived Stress Scale (PSS), and Oral Analog Scale were used for assessment. The Beck Anxiety Scale is composed of 21 multiple-choice questions describing symptoms of anxiety, while the PSS is a measure that evaluates life situations as stressful. An Oral Analogue Scale was applied to each individual to quantify orofacial pain, with 0 (zero) without pain and 10 (ten) being the worst pain ever felt. The comparison between groups was performed using the Mann-Whitney test. Logistic regression was used to verify TMD dependence in relation to BAI and PSS-10. Quantitative variables were correlated with each other by Pearson's correlation coefficient. The level of significance considered for all tests was 5%. Results: The association was statistically significant (p≤0.05) for BAI and PSS with a TMD. Conclusion: Although the COVID 19 pandemic has had a psychological impact on the general population, patients with TMD have higher levels of anxiety and stress than the control group.

Preemptive use of intravenous ibuprofen to reduce postoperative pain after lower third molar surgery: a systematic review of randomized controlled trials.

This study aimed to systematically review the literature to assess the effect of preemptive intravenous ibuprofen on pain reduction after lower third molar surgery. Nine databases (PubMed, Scopus, LILACS, SciELO, Embase, Web of Science, Cochrane, Open Gray, and Open Thesis) were used as sources of research, including "grey literature." The protocol was registered in PROSPERO. Only randomized clinical trials evaluating the effects of preemptive intravenous ibuprofen on pain during and immediately after the extraction of lower third molars were included, without restrictions of year and language. Two reviewers independently performed the study selection, data extraction, and assessment of the risk of bias. The "Joanna Briggs Institute for Randomized Controlled Trials" tool was used to assess the risk of bias. Each study was categorized according to the percentage of positive responses to the questions corresponding to the assessment instrument. The results were measured narratively/descriptively. The initial search resulted in 3,257 records, of which only three studies (n=150 participants) met the eligibility criteria and were included in the qualitative analysis. All studies were published in 2019. The risk of bias ranged from low to moderate. Two studies found significant pain reduction within 48 h after the procedure. In conclusion, the use of preemptive intravenous ibuprofen for extracting third molars reduces pain and analgesic consumption after the surgical procedure.

35 Year achievements of Brazilian Oral Research.

This editorial addresses the history of Brazilian Oral Research (BOR), official journal of the Brazilian Division of the International Association of Dental Research (SBPqO). BOR is increasingly consolidating itself as the most important journal in Brazilian dental research. However, much still needs to be done. The hard and continuous work to improve the journal will guarantee its permanent growth and result in new achievements for the benefit of the entire dental scientific community.

Toxicity and effect of whitening toothpastes on enamel surface.

This in vitro study evaluated the biocompatibility and abrasivity of whitening and conventional toothpastes. Samples of conventional (non-whitening) - Edel White Infant (EWI) - and whitening toothpastes - Edel White Whitening (EWW), Edel White CAREFORTE (EWC), Colgate Total 12 Ò Professional (C), and Oral-B Whitening (OB) - were dissolved in culture medium (0.2 g sample weight per mL). Human gingival fibroblasts (hGF) were placed in contact with different dilutions of culture media that had been previously exposed to these toothpastes. Cytotoxicity was then assessed using the methyl tetrazolium test (MTT) and the cell survival rate was determined. Genotoxicity was assessed by the micronucleus test (MNT) and the number of micronuclei was determined before and after exposure to the toothpaste solutions. The enamel surface roughness was evaluated in specimens of bovine teeth (n = 10 per group) before and after 10,000 brushing cycles, using the investigated toothpastes. The results were statistically analyzed using the Mann-Whitney U test and two-way ANOVA (p < 0.05). According to the MTT assay, EWW and OB presented significant cytotoxicity (p < 0.01), but no genotoxic (MNT) effects (p > 0.05). C toothpaste was statistically significantly abrasive to the enamel surface (p < 0.01). The findings of this study may be helpful for individualized selection of commercial toothpastes, as some whitening toothpastes present significant cytotoxicity and conventional toothpaste cause significant surface changes.

Influence of dental erosion on shear bond strength of ceramic brackets bonded with two different adhesive systems: an in vitro study

This study aimed to analyze the shear bond strength (SBS) of ceramic orthodontic brackets bonded with two different adhesive systems to intact and eroded teeth. Ceramic brackets were bonded to 72 bovine central incisors divided into four groups, defined by two study factors: enamel condition (control group, kept in artificial saliva; and experimental group, eroded by using immersion cycles in Coke™ for 90 seconds, every six hours for five days), and adhesive system type (Transbond™ XT or Transbond™ Plus Color Change). Polycrystalline ceramic brackets were adhesively fixed on all specimens using the same light curing protocol. SBS was tested using 0.5 mm/min and the failure mode was classified. SBS data was analyzed using two-way ANOVA followed by Tukey test. The adhesive remnant index (ARI) scores were analyzed using Kruskal-Wallis test with Dunn's post-hoc pairwise comparison (α=0.05). Percentages of ARI scores between the groups were compared by Fisher's exact test. Spearman's correlation coefficient was applied to investigate the correlation between ARI scores and SBS values. Only the adhesive system factor had significant effect on SBS (p=0.014), Transbond™ Plus Color Change showing higher values. No significance was found for enamel condition (p=0.665) or the interaction between adhesive system and enamel condition (p=0.055). ARI scores frequencies differed between groups (p<0.001). The median ARI scores were statistically different for most comparisons among the groups. However, no significant correlation was found between ARI scores and SBS. In conclusion, the type of adhesive system affected the SBS of ceramic brackets to dental enamel, but the enamel condition, intact or eroded, had no significant effect. There was no correlation between ARI scores and SBS values, although eroded enamel tended to retain more adhesive after bracket removal.

Preemptive use of intravenous ibuprofen to reduce postoperative pain after lower third molar surgery: a systematic review of randomized controlled trials

This study aimed to systematically review the literature to assess the effect of preemptive intravenous ibuprofen on pain reduction after lower third molar surgery. Nine databases (PubMed, Scopus, LILACS, SciELO, Embase, Web of Science, Cochrane, Open Gray, and Open Thesis) were used as sources of research, including "grey literature." The protocol was registered in PROSPERO. Only randomized clinical trials evaluating the effects of preemptive intravenous ibuprofen on pain during and immediately after the extraction of lower third molars were included, without restrictions of year and language. Two reviewers independently performed the study selection, data extraction, and assessment of the risk of bias. The "Joanna Briggs Institute for Randomized Controlled Trials" tool was used to assess the risk of bias. Each study was categorized according to the percentage of positive responses to the questions corresponding to the assessment instrument. The results were measured narratively/descriptively. The initial search resulted in 3,257 records, of which only three studies (n=150 participants) met the eligibility criteria and were included in the qualitative analysis. All studies were published in 2019. The risk of bias ranged from low to moderate. Two studies found significant pain reduction within 48 h after the procedure. In conclusion, the use of preemptive intravenous ibuprofen for extracting third molars reduces pain and analgesic consumption after the surgical procedure.

Toxicity and effect of whitening toothpastes on enamel surface

Abstract This in vitro study evaluated the biocompatibility and abrasivity of whitening and conventional toothpastes. Samples of conventional (non-whitening) - Edel White Infant (EWI) - and whitening toothpastes - Edel White Whitening (EWW), Edel White CAREFORTE (EWC), Colgate Total 12 Ò Professional (C), and Oral-B Whitening (OB) - were dissolved in culture medium (0.2 g sample weight per mL). Human gingival fibroblasts (hGF) were placed in contact with different dilutions of culture media that had been previously exposed to these toothpastes. Cytotoxicity was then assessed using the methyl tetrazolium test (MTT) and the cell survival rate was determined. Genotoxicity was assessed by the micronucleus test (MNT) and the number of micronuclei was determined before and after exposure to the toothpaste solutions. The enamel surface roughness was evaluated in specimens of bovine teeth (n = 10 per group) before and after 10,000 brushing cycles, using the investigated toothpastes. The results were statistically analyzed using the Mann-Whitney U test and two-way ANOVA (p < 0.05). According to the MTT assay, EWW and OB presented significant cytotoxicity (p < 0.01), but no genotoxic (MNT) effects (p > 0.05). C toothpaste was statistically significantly abrasive to the enamel surface (p < 0.01). The findings of this study may be helpful for individualized selection of commercial toothpastes, as some whitening toothpastes present significant cytotoxicity and conventional toothpaste cause significant surface changes.

Evaluation of the masticatory biomechanical function in Down syndrome and its Influence on sleep disorders, body adiposity and salivary parameters.

OBJECTIVE: To evaluate the phenotypic features of the masticatory biomechanics in atypical subjects with Down syndrome (DS). Its influence was analysed on sleep disorders, body adiposity and its risks, and some physicochemical properties of saliva. METHODS: Seventy subjects were enrolled to assess masticatory biomechanical function and divided into two groups: DS and control groups. Electrical activities of the masseter and temporal muscles (at rest and in maximum voluntary clench-MVC), maximum bite force-MBF and maximum mouth opening-MMO were investigated. Among the atypical subjects, just 24 participants underwent the anthropometry, the polysomnography II and the saliva testing (salivary flow rate-SFR, buffer capacity-BC and salivary cortisol levels, morning/SC-AM and night/SC-PM). RESULTS: MVC and MBF values showed high statistical significance in the control group (P < .001) than in the DS group of 35. MMO values were slightly increased in the DS group in relation to the control group. Overweight and obesity were found in both genders. Atypical women showed higher risk to develop cardiovascular-metabolic diseases than in atypical men. OSA severe was 20% for atypical women and 42.8% for atypical men, whereas snoring index was present in all genders. SFR was reduced in 100% of atypical subjects (hyposalivation in 10% women and 28.5% men). Furthermore, 100% BC, 66.6% SC-AM and 91.6% SC-PM showed normal patterns. CONCLUSION: Masseter and temporal muscle hypotonia was found in all atypical subjects with DS. This muscle dysfunction strongly was related to overweight/obesity, risks for development of cardiovascular/metabolic diseases, OSA severity, successive snoring episodes and salivary flow reduction in DS.

Os efeitos da Punica granatum L. em diferentes concentrações sobre duas linhagens celulares: estudo in vitro / The effects of Punica granatum L. at different concentrations on two cell lines: in vitro study

Introdução: A Punica granatum L. (PG), utilizada como medicamento fitoterápico, apresenta propriedades terapêuticas, anti-inflamatórias e antioxidante. Embora diversos estudos já tenham sido realizados com este fitoterápico, seus possíveis efeitos citotóxicos nos tecidos humanos ainda não são claros. Objetivo: Avaliar a citotoxicidade da PG por meio de cultura celular com duas linhagens: fibroblastos humanos de mucosa oral (FLM) e células de carcinoma epidermoide oral humano (KB). Material e método: As células foram submetidas ao teste de viabilidade celular por 24 horas nas concentrações da PG 1%, 0,50%, 0,25%, 0,125%, 0,062% e 0,031%, e aos testes de citotoxicidade celular em 4 horas, 1, 3, 5 e 7 dias, em diferentes concentrações, realizados em triplicata. Foi utilizado um controle negativo (Triton 1%) e um controle positivo sem o extrato de PG. Os dados obtidos foram submetidos à ANOVA (p < 0,05). Resultado: Foi possível observar que o extrato da PG possui efeitos inibitórios, apresentando-se maior nas células KB em relação às FLM. Os testes de citotoxicidade e viabilidade mostraram inibição e morte das células KB e FLM nas concentrações 1%, 0,50% e 0,25%. Conclusão: O efeito inibitório da PG foi dose-dependentes, mostrando-se maior nas células KB em relação às FLM.

Introduction: Punica granatum L. (PG), used as a herbal medicine, has therapeutic, anti-inflammatory and antioxidant properties, although several studies have already been carried out with this herbal medicine, its possible cytotoxic effects on human tissues are still unclear. Objective: To evaluate the cytotoxicity of PG through cell culture with two strains: human oral mucosa fibroblasts (LFM) and human oral squamous cell carcinoma (KB) cells. Material and method: The cells were submitted to the cell viability test for 24 hours in the concentrations of PG 1%, 0.50%, 0.25%, 0.125%, 0.062% and 0.031% and the cell cytotoxicity tests in 4 hours, 1, 3, 5 and 7 days in different concentrations, performed in triplicate. A negative control (Triton 1%) and a positive control without the PG extract were used. The data obtained were submitted to ANOVA (p <0.05). Result: it was possible to observe that the PG extract has inhibitory effects, being higher in KB cells in relation to LFM. The cytotoxicity and viability tests showed inhibition and death of KB and FLM cells at concentrations of 1%, 0.50% and 0.25%. Conclusion: The inhibitory effect of PG was dose dependent, showing itself to be greater in KB cells compared to LMB.

Comparação da exotermia de resinas durante a restauração provisória direta / Comparison of resin exotherm during direct provisional restoration

Resumo Introdução As resinas de polimetilmetacrilato e as bisacrílicas são materiais amplamente utilizados para a confecção de restaurações provisórias; no entanto, ambas apresentam uma característica de exotermia durante a polimerização que deve ser investigada por causa de possíveis interferências no sucesso clínico. Objetivo Avaliar a variação de temperatura de polimerização da resina bisacrílica e de uma resina acrílica quimicamente ativada, em preparos classe V, pelo método direto. Material e método Para isso, vinte dentes incisivos inferiores bovinos foram divididos em dois grupos: RA (N=10) com dentes restaurados com resina acrílica e RB (N=10) com dentes restaurados com resina bisacrílica. As mensurações das variações térmicas foram realizadas através de termopares tipo J, ligados a um termômetro óptico, e analisadas por um computador equipado com o software específico. Os dados obtidos foram analisados e submetidos à análise de médias comparadas pelo teste de Tukey (significância de 5%). Resultado Foi possível observar que não houve diferença estatística significante entre ambos os grupos experimentais (p=0,0739), mesmo que aumento de temperatura de RA tenha apresentado média maior (0,52 °C) do que RB (0,44 °C). Conclusão Não existe diferença significativa experimental entre o calor emitido pela resina acrílica e pela resina bisacrílica durante seus processos de polimerização, não definindo a característica de escolha de uma destas para as restaurações provisórias diretas.

Abstract Introduction Polymethyl methacrylate and bis-acryl resins are materials widely used for temporary restorations, however, both have a characteristic of polymerization exotermia that should be investigated because of possible interferences in clinical success. Objective to evaluate the variation of the polymerization temperature of bis-acryl resin and a chemically activated acrylic resin in the temporary restoration by the direct method. Material and method Twenty bovine mandibular incisor teeth were divided into two groups: AR (N = 10) teeth restored with acrylic resin and BR (N = 10) teeth restored with bis-acryl resin. Measurements of thermal variations were performed using type J thermocouples, connected to an optical thermometer and analyzed by a computer equipped with specific software. The obtained data were analyzed and submitted to the analysis of means compared by Tukey test (significance of 5%). Result It was observed that there was no statistically significant difference between both experimental groups (p = 0.0739), even though AR temperature increase presented higher average (0.52ºC) than BR (0.44ºC). Conclusion There is no significant experimental difference between the heat emitted by acrylic resin and bis-acryl resin during their polymerization processes, not defining the factor that characterizes a choice of a material for temporary restorations.

Effect of two erosive protocols using acidic beverages on the shear bond strength of orthodontic brackets to bovine enamel

Abstract Objective: To assess the short-term effect of two in vitro erosive challenge protocols on the bond strength of metal orthodontic brackets on bovine enamel. Methods: Sixty bovine incisors were selected and randomly divided into six groups: AS7 (artificial saliva - 7 days, Control Group); CC7 (Coca-Cola™ - 7 days); LJ7 (lime juice - 7 days); AS30 (artificial saliva - 30 days, Control Group); CC30 (Coca-Cola™ - 30 days); LJ30 (lime juice - 30 days). Microhardness testing was performed prior to the erosive challenge to verify the standardization of samples. Immersion was performed 4x/day for five minutes, for either 7 or 30 days. After immersions were concluded, the brackets were bonded and shear bond strength was assessed after 48 hours. The Adhesive Remnant Index (ARI) was also assessed. Data were analyzed by two-way ANOVA, followed by Tukey's post-hoc and Student's t test for paired samples, and the Kruskal-Wallis non-parametric test (α = 5%). Results: The mean and standard deviation of microhardness testing of total samples were 281.89 ± 44.51 KHN. There was no statistically significant difference in shear bond strength for the time factor (7 or 30 days; F5.54= 0.105; p = 0.901). However, there was a statistically significant difference for the solution factor (F5.54= 6.671; p = 0.003). These differences occurred among solutions of Saliva x Coca-Cola™ (p = 0.003) and Coca-Cola™ x Lime Juice (p= 0.029). The assessment of the Adhesive Remnant Index showed no significant difference between groups. Conclusions: The immersion time used in the erosion protocols did not affect the bond strength of brackets to teeth. Coca-Cola™ induced significantly higher shear bond strength values than lime juice and artificial saliva. However, the short term effects of 7/30 days in this in vitro study may not be extrapolated for in vivo ones. Clinical studies should be conducted, substantiating the laboratory results.

Resumo Objetivo: avaliar o efeito de curto prazo de dois protocolos de desafio erosivo, in vitro, na resistência adesiva de braquetes ortodônticos metálicos em esmalte bovino. Métodos: Sessenta incisivos bovinos foram selecionados e divididos aleatoriamente em seis grupos: SA7 (saliva artificial - 7 dias, Grupo Controle); CC7 (Coca-Cola® - 7 dias); SL7 (suco de limão - 7 dias); SA30 (saliva artificial - 30 dias, Grupo Controle); CC30 (Coca-Cola® - 30 dias); SL30 (suco de limão - 30 dias). Foi realizado o teste de microdureza antes do desafio erosivo, para verificar a padronização das amostras. A imersão foi realizada quatro vezes ao dia, por cinco minutos, durante 7 ou 30 dias. Finalizadas as imersões, os braquetes foram colados e, após 48 horas, foi avaliada a resistência ao cisalhamento. O Índice de Adesivo Remanescente (IAR) também foi avaliado. Para análise dos dados, foram utilizados os testes ANOVA dois fatores, seguido do post-hoc de Tukey e teste t de Student para amostras pareadas, e o teste não-paramétrico de Kruskal-Wallis (α?#8197;= 5%). Resultados: a média e o desvio-padrão do teste de microdureza das amostras totais foi igual a 281,89 ± 44,51 KHN. Não houve diferença estatisticamente significativa na resistência ao cisalhamento para o fator tempo (7 ou 30 dias; F5,54= 0,105; p= 0,901). Contudo, houve diferença estatisticamente significativa para o fator solução (F5,54=6,671; p= 0,003). Essas diferenças ocorreram entre as soluções de Saliva x Coca-Cola® (p= 0,003) e Coca-Cola® x suco de limão (p= 0,029). Ao avaliar o Índice de Adesivo Remanescente, não foi possível verificar diferença significativa entre os grupos. Conclusões: o tempo de imersão utilizado nos protocolos de erosão não afetou a resistência de união dos braquetes aos dentes. A Coca-Cola® induziu valores de resistência ao cisalhamento significativamente mais altos do que o suco de limão e a saliva artificial. No entanto, os efeitos em curto prazo de 7 e 30 dias, nesse estudo in vitro, não podem ser extrapolados para os estudos in vivo. Estudos clínicos devem ser conduzidos, fundamentando os resultados laboratoriais.