Abstract In this study, we describe a method for reaching a target population (i.e., dentists practicing in Brazil) to engage in survey research using traditional e-mail invites and recruitment campaigns created on Instagram. This study addresses methodological aspects and compares respondents reached by different methods. A pre-tested questionnaire was used and participants were recruited for 10 days via a source list of email addresses and two discrete Instagram organic open campaigns. A total of 3,122 responses were collected: 509 participants were recruited by email (2.1% response rate) and 2,613 by the two Instagram campaigns (20.7% and 11.7% conversion rates), respectively. Response/min collection rates in the first 24 h ranged between 0.23 (email) and 1.09 (first campaign). In total, 98.8% of all responses were received in the first 48 h for the different recruitment strategies. There were significant differences for all demographic variables (p< 0.001) between email and Instagram respondents, except for sex (p=0.37). Instagram respondents were slightly older, had more professional experience (years in practice), and a higher graduate education level than email respondents. Moreover, most email and Instagram respondents worked in the public sector and private practice, respectively. Although both strategies could collect responses from all Brazilian regions, email responses were slightly better distributed across the five territorial areas compared to Instagram. This study provides evidence that survey recruitment of a diverse, large population sample using Instagram is feasible. However, combination of email and Instagram recruitment led to a more diverse population and improved response rates.
Resumo Neste estudo, descrevemos um método para atingir uma população-alvo (dentistas atuando no Brasil) para se engajar em pesquisa do tipo enquete (survey) utilizando convites tradicionais por e-mail e campanhas de recrutamento criadas no Instagram. Este estudo aborda aspectos metodológicos e compara as pessoas entrevistadas alcançadas por diferentes métodos. Foi utilizado um questionário pré-testado e os(as) participantes foram recrutados(as) por 10 dias por meio de uma lista de endereços de e-mail e duas campanhas abertas orgânicas independentes no Instagram. Foram coletadas 3122 respostas: 509 participantes foram recrutados(as) por e-mail (taxa de resposta 2,1%) e 2613 pelas duas campanhas do Instagram (taxas de conversão 20,7% e 11,7%), respectivamente. As taxas de coleta de resposta/min nas primeiras 24h variaram entre 0,23 (e-mail) e 1,09 (primeira campanha). No total, 98,8% das respostas foram recebidas nas primeiras 48h para as diferentes estratégias de recrutamento. Houve diferenças significativas para todas as variáveis demográficas (p<0,001) entre recrutados(as) por e-mail e Instagram, com exceção de sexo (p=0,37). As pessoas recrutadas via Instagram eram um pouco mais velhas, tinham mais experiência profissional (anos na prática) e nível de pós-graduação superior às entrevistadas por e-mail. Além disso, a maioria dos entrevistados por e-mail e Instagram trabalhava no setor público e na prática privada, respectivamente. Embora ambas estratégias tenham sido capazes de coletar respostas de todas as regiões brasileiras, as respostas por e-mail foram ligeiramente melhor distribuídas nas cinco áreas territoriais em comparação ao Instagram. Este estudo fornece evidências de que o recrutamento de uma amostra de população diversificada e grande usando o Instagram é viável. No entanto, a combinação de e-mail e Instagram no recrutamento levou a uma população mais diversificada e melhores taxas de resposta.
Abstract The effect of root canal preparation technique on microcrack initiation is a controversial issue. This systematic review aimed to assess the role of root canal preparation techniques with different kinematics (manual, rotary, reciprocating, adaptive, self-adjusting file) on microcrack initiation. In vitro and in situ studies comparing the influence of at least two different root canal preparation techniques on the initiation of dentin microcracks were searched in PubMed/MEDLINE and SCOPUS up to June 5, 2018 without language and period restriction. Two authors independently reviewed all identified titles and abstracts for eligibility. Tables were generated to summarize the included studies, and the included studies were assessed for bias. Fifty-four (n=54) articles met the eligibility criteria. The results were classified according to the method used for microcrack evaluation, and most studies that used micro-computed tomography showed no formation of new cracks after root canal preparation. In general, the instrumentation techniques induced microcrack formation when the methods were destructive, irrespective of kinematics. In relation to the apex region, when the preparation working length was set as the root canal length subtracted of 1 mm, the risk of microcrack initiation reduces. The majority of the included studies had low risk of bias for all assessed domains. Our results seem to indicate that the various root canal preparation techniques considered in this study will not cause damage to the dental structure when adequately employed and the proper methodology is applied.
Resumo O efeito da técnica de preparo do canal radicular na iniciação e/ou propagação de microfissuras dentinárias é um tema controverso. Essa revisão sistemática teve como objetivo avaliar o papel das técnicas de preparo do canal radicular com diferentes cinemáticas (manual, rotatória, reciprocante, adaptativa e self-adjusting file) na iniciação e/ou propagação de microfissuras dentinárias. Estudos in vitro e in situ comparando a influência de pelo menos duas técnicas diferentes de preparo do canal radicular foram identificados no PubMed/MEDLINE e SCOPUS até 05 de junho de 2018 sem restrição de idioma e tempo. Dois autores revisaram de maneira independente todos títulos e resumos para elegibilidade dos estudos. Tabelas foram criadas para sumarizar os estudos incluídos e os estudos foram avaliados quanto ao risco de viés. Cinquenta e quatro (54) estudos enquadraram-se nos critérios de elegibilidade. Os resultados foram classificados de acordo com o método utilizado para avaliação das microfissuras. A maioria dos estudos que utilizaram micro-tomografia não demonstraram formação de novas microfissuras após preparo do canal radicular. Em geral, técnicas de instrumentação induziram formação de microfissuras quando os métodos de avaliação foram destrutivos, independente da cinemática. Em relação a região do ápice, quando comprimento de trabalho foi definido como o comprimento do canal menos 1 mm, o risco de indução de microfissuras é reduzido. A maioria dos estudos incluídos apresentaram baixo risco de viés para todos os domínios apresentados. Nossos resultados parecem indicar que as diferentes técnicas de preparo do canal radicular não causam danos a estrutura dental quando adequadamente utilizadas e a metodologia adequada é utilizada.
Abstract The aim of this study was to investigate the mechanical performance and the fracture behavior of endocrown restorations prepared using distinct restorative materials. A total of 42 sound molars with similar crown size and shape were cut at 2 mm above the cementoenamel junction and endodontically treated. They were categorized according to the restorative material used to fabricate endocrown restorations (n=7), namely, conventional composite (Filtek™ Z350 XT), bulk fill composite (Filtek™ Bulk Fill), conventional composite modeled using resin adhesives (SBMP: Scotchbond™ Multipurpose Adhesive; or SBU: Scotchbond™ Universal Adhesive), and IPS e.max lithium disilicate (Ivoclar Vivadent; positive control). Unprepared sound teeth were used as negative control. All endocrowns were bonded using a self-adhesive cement (Rely-X™ U200). The teeth were submitted to fatigue (Byocycle) and fracture (EMIC DL500) testing. Load-to-fracture (in N) and work-of-fracture (Wf, in J/m2) values were analyzed by ANOVA (p < 0.05). The endocrowns did not fracture or de-bond upon fatigue, showing similar load-to-fracture and work-of-fracture values, regardless of the restorative material (p > 0.05). The endocrowns fabricated by combining Z350 and SBMP had the least harsh fractures, in contrast to endocrowns prepared using Z350 only, which exhibited an equilibrium between repairable and irrepairable fractures. The e.max endocrowns exhibited more aggressive failures (root fracture) than other groups, resulting in higher rates of irrepairable fractures. In conclusion, dental practitioners may satisfactorily restore severely damaged nonvital teeth using the endocrown technique. Composite endocrowns prepared using resin adhesive as modeler liquid or using bulk fill material may result in less aggressive failures, thus providing a new material perspective for endocrown restorations.
Abstract The use of reporting guidelines has an important role in the development of health research, improving the quality and precision of the publications. This study evaluated how dental journals use reporting guidelines. All editors of dental journals registered on the 2013 Journal Citation Reports list (n=81) were invited to participate. The data were collected by a self-reported web-based questionnaire. Information about the profile of journal/editor and on the use of reporting guidelines by journals was gathered. Information/recommendations about the use of reporting guidelines were collected from the websites of all journals. Data were descriptively analyzed and frequencies were summarized. Thirty-four (42%) editors completed the questionnaire. Most journals are members of Committee on Publication Ethics (64.7%) and/or follow the International Committee of Medical Journal Editors recommendations (20.6%), while 26.5% are not members of any editorial group. Most editors are unfamiliar with the EQUATOR Network (55.9%), do not work full time (85.3%) and 88.2% have some income/payment. Most of them received educational training for this position (55.9%). The CONSORT Statement was endorsed by 61.8% of journals. Information from websites showed that 44.4% journals do not recommend any reporting guideline, 51.9% mention CONSORT Statement in the website and 28.4% only recommend the use of CONSORT Statement. There is clearly room for improving the use of reporting guidelines in dental journals. Broadening the understanding and the endorsement/adherence/implementation of reporting guidelines by journals may promote quality and transparence of published dental research.
Resumo O uso de guias de reporte tem um papel importante no desenvolvimento das pesquisas na saúde, melhorando a qualidade e a precisão das publicações. Esse estudo avaliou como periódicos de odontologia usam os guias de reporte. Todos editores de periódicos de odontologia registrados na lista do 2013 Journal of Citation Reports (n=81) foram convidados a participar. Dados foram coletados através de um questionário online autoaplicável. Informações sobre o perfil do periódico/editor e do uso de guias de reporte pelos periódicos foram coletados. Informações/recomendações sobre o uso de guias de reporte foram também coletados dos sites de todos os periódicos. Dados foram analisados descritivamente e frequências foram sumarizadas. Trinta e quatro (42%) editores completaram o questionário. Maioria dos periódicos é membro do Committee on Publication Ethics (64,7%) e/ou seguem as recomendações do International Committee of Medical Journal Editors (20,6%), enquanto 26,5% dos periódicos não são membros de nenhum grupo editorial. A maioria dos editores não é familiar com o EQUATOR Network (55,9%), não trabalha em tempo integral como editor (85,3%) e 88,2% recebem algum pagamento. A maioria deles recebeu treinamento para a posição de editor (55,9%). O CONSORT Statement foi endossado por 61,8% dos periódicos. Informações oriundas dos sites demonstraram que 44,4% dos periódicos não recomendam nenhum guia de reporte, 51,9% mencionam o CONSORT Statement no site e 28,4 apenas recomenda o CONSORT Statement. Existe um espaço claro para melhora no uso de guias de reporte em periódicos de odontologia. Um maior entendimento e endosso/aderência/implementação de guias de reporte por periódicos de odontologia pode promover a qualidade e transparência das pesquisas odontológicas publicadas.
Abstract Resin cements are often used for single crown cementation due to their physical properties. Self-adhesive resin cements gained widespread due to their simplified technique compared to regular resin cement. However, there is lacking clinical evidence about the long-term behavior of this material. The aim of this prospective clinical trial was to assess the survival rates of metal-ceramic crowns cemented with self-adhesive resin cement up to six years. One hundred and twenty-nine subjects received 152 metal-ceramic crowns. The cementation procedures were standardized and performed by previously trained operators. The crowns were assessed as to primary outcome (debonding) and FDI criteria. Statistical analysis was performed using Kaplan-Meier statistics and descriptive analysis. Three failures occurred (debonding), resulting in a 97.6% survival rate. FDI criteria assessment resulted in scores 1 and 2 (acceptable clinical evaluation) for all surviving crowns. The use of self-adhesive resin cement is a feasible alternative for metal-ceramic crowns cementation, achieving high and adequate survival rates.
Abstract The aim of this study is to evaluate the influence of modeling liquids on the translucency and color shade of resin composites (RCs) after one year of storage. RC specimens were prepared using either a conventional insertion technique (control; without modeling liquid) or a restorative dental modeling insertion technique (RDMIT) with dental adhesives as modeling liquids (Scotchbond™ Multi-Purpose [SBMP; 3M ESPE] or Adper™ Single Bond 2 [SB; 3M ESPE]). The initial colors of the specimens were obtained with a digital spectrophotometer and the CIEL*a*b* color system, after which specimens were stored (37°C) in distilled water or red wine for 12 months. Color measurements were reassessed after 6 and 12 months of storage, and scanning electron microscopy was performed after 12 months. Translucency and color change (ΔE*) were calculated and analyzed using ANOVA and Tukey’s test (α = 5%). RC samples prepared via RDMIT showed a translucency similar to that of control samples. ΔE* was also less intense for RCs containing SBMP than for RCs containing SB. Specimens stored in wine showed a clear pattern of degradation, especially in the control group, and surface degradation seemed to be less intense for specimens prepared with SBMP and SB than for specimens without. Specimens stored in water did not show clear evidence of surface degradation. RDMIT appears to be an interesting approach to reduce ΔE* in RCs over time without negative effects on the translucency of the material. However, the modeling liquid should feature a hydrophobic composition, similar to that used in the SBMP group, the achieve the best results.
Abstract This study evaluated retrospectively the association among occlusal, periodontal and implant-prosthetic parameters and marginal bone loss (MBL) around implants and survival rate at 5.7 ±3.2 years of follow-up after prosthetic loading. Eighty-two patients received 164 external hexagon implants. After the standard healing period (3 to 6 months), the implants were restored with single-tooth or up to three splinted crowns. All patients were followed according to a strict maintenance program with regular recalls and clinically evaluated by a calibrated examiner. The MBL measurements taken from standardized radiographs made at permanent crown placement (baseline) and after the last evaluation were calculated considering occlusal, periodontal and implant-prosthetic parameters. Veneer fractures and abutment loosening were not considered failure. Two implants failed during the follow-up period, resulting in a survival rate of 98.8%. Cox regression analyses showed MBL associated with non-working side contacts (p=0.047), inadequate anterior guidance (p=0.001), lateral group guidance involving teeth and implants (p=0.015), periimplant plaque index (p=0.035), prosthetic design (p=0.030) and retention (p=0.006). Inadequate occlusal pattern guide, presence of visible plaque, and cemented and splinted implant-supported restoration were associated with greater MBL around the implant.
Resumo Este estudo avaliou retrospectivamente a associação entre os parâmetros oclusais, periodontais e implante-protéticos e perda óssea marginal (POM) ao redor de implantes e taxa de sobrevivência, em 5,7 ± 3,2 anos de acompanhamento após o carregamento protético. Oitenta e dois pacientes receberam um total de 164 implantes com hexágono externo. Após o período de cicatrização (3 à 6 meses), os implantes foram restaurados com coroa unitária ou até três coroas ferulizadas. Todos os pacientes seguiram um programa de manutenção rigoroso, com consultas regulares e avaliações clinicas realizadas por um examinador calibrado. As medições de POM obtidas de radiografias padronizadas realizadas na colocação da coroa permanente (baseline) e após a última avaliação foram calculadas considerando os parâmetros oclusais, periodontais e àqueles relacionados ao implante e prótese. Fratura na cerâmica de cobertura e afrouxamento do pilar não foram considerados falhas. Dois implantes falharam durante o período de acompanhamento, resultando em uma taxa de sobrevivência de 98,8%.A análise de regressão de Cox mostrou POM associado com contatos no lado de balanceio (p= 0,047), inadequada guia anterior (p=0,001), guia lateral em grupo envolvendo dentes e implantes (p=0,015), índice de placa visível em torno do implante (p=0,035), tipo de prótese (p= 0,030) e retenção (p=0,006). Guia de padrão oclusal inadequado, presença de placa visível e restaurações implanto-suportadas cimentadas e ferulizadas resultaram em maior POM ao redor do implante.
Abstract The aim of the present study was to investigate the success and survival of restored endodontically treated teeth (ETT) in a general practice environment related to periodontal parameters. Data from 360 restored ETT treated between 2000 and 2011 were collected. Dates of interventions like restorations, repairs, replacements and extractions were recorded. Additionally, general information about patients and dentitions as well as periodontal status was recorded. Success was analyzed using Kaplan-Meier statistics and a multivariate Cox regression analysis was performed to assess variables influencing success and survival. After a mean observation time of 4.34 years (range 0.6 - 11.6 years), 19 teeth were extracted and 27 restorations needed repair or replacement. According to the Cox regression, increasing maximum pocket depth of the tooth resulted in a higher risk for failure (p=0.012). In conclusion, periodontal pocket depth was found to be a significant factor in the survival of restored ETT.
Resumo O objetivo do presente estudo foi investigar a taxa de sucesso e de sobrevivência de dentes restaurados e tratados endodonticamente (DTE) em uma clínica privada e relacionar com índices periodontais. Dados de 360 restaurações realizadas em DTE realizadas entre 2000 e 2011 foram coletados. As datas das intervenções, como restaurações, reparos, substituições e extrações foram registradas. Ainda, informações gerais relacionadas aos pacientes, aos dentes envolvidos e ao estado periodontal foram também coletadas. A taxa de sucesso foi analisada utilizando o método estatístico Kaplan-Meier e uma análise multivariada do tipo regressão de Cox foi realizada para avaliar variáveis que influenciaram na taxa de sucesso e de sobrevivência. Depois de um período de observação médio de 4,34 anos (0,6-11,6 anos), 19 dentes foram extraídos e 27 restaurações precisaram de reparo ou substituição. De acordo com a regressão de Cox, o aumento na profundidade de bolsa periodontal do dente resulta em um maior risco de falha (p=0,012). Em conclusão, a profundidade de bolsa periodontal foi considerada como um fator significativo na sobrevivência de dentes restaurados e tratados endodonticamente.
Abstract Modeling liquids/resins have been used to build up resin composite (RC) restorations, although there is a lack of information regarding their effects on the color stability of the latter. Therefore, the purpose of the present study was to evaluate the effects of the presence of modeling liquid between layers of RC and the finishing/polishing state of the material on color change in specimens exposed to red wine staining over time. Specimens were prepared by placing four increments (±0.5 mm thick) of RC (Filtek™ Z350 XT, 3M ESPE) into molds; half of which were prepared by applying modeling liquid (Scotchbond™ Multi-Purpose™ Adhesive, SBMP, 3M ESPE) between the layers of RC, whereas the other half were prepared without SBMP (control). Light-activation was performed after application of the final RC layer using a light-emitting diode (Radii, SDI) curing unit with an irradiance of 900 mW/cm2 for 20 s. Each group was divided according to the surface finishing protocol (n = 7): nothing (non-polished) or polishing with Sof-Lex™/diamond paste (polished). Initial colors of the specimens were evaluated with a digital spectrophotometer and the CIEL*a*b* color system. The specimens were stored in wine (37°C) for 12 months, and the color measurements were reassessed after 4, 6, and 12 months of storage. Scanning electron microscopy (SEM) analysis was performed at the end. Data were analyzed using ANOVA and Tukey’s test (α = 5%). The presence of SBMP resulted in lower overall color change of the RC as compared with the control. The non-polished specimens exhibited a significantly higher color change than the polished specimens. SEM images corroborated the previous findings. In summary, the use of modeling liquid between layers of RC shows potential for application to reduce or delay the staining process of RC over time. Moreover, polishing is essential to provide increased color stability of the RC restoration.
This study aimed to evaluate the effect of chlorhexidine (CHX) application on etched dentin on the 6-month retention of restorations placed on non-carious cervical lesions (NCCLs). A randomized controlled split-mouth and triple blind trial was carried out. Patients (n=42) with at least two non-carious cervical lesions were included. NCCLs were randomly assigned to two groups: control (placebo solution) or test group (2% CHX solution for 60 s after acid etching and before the adhesive application). Class V restorations (n=169) were performed with an etch-and-rinse adhesive system and composite resin by 10 trained operators. A calibrated examiner evaluated the restorations at 1 week (baseline) and at 6 months using the FDI criteria. The primary outcome was retention of the restorations. The analysis of factors associated to failure of restorations was carried out by Fisher's exact test (α=0.05). After 6 months of follow-up, 3.4% (CI 95% 1.3-7.3) of the restorations failed. There was no statistically significant difference between control and CHX (p=0.920). Regarding the cavity variables, deeper (p=0.04), wider (p=0.004) and wedge-shaped (p=0.033) cavities failed more. Both treatments provided acceptable clinical performance of the restorations. The use of CHX as a adjuvant in dentin adhesion did not influence the retention of Class V restorations after 6 months of follow-up.
O objetivo deste estudo foi avaliar o efeito da aplicação de clorexidina (CRX) em dentina condicionada na retenção de restaurações confeccionadas em lesões cervicais não-cariosas (LCNC) após 6 meses. Ensaio clínico randomizado triplo cego do tipo boca dividida foi conduzido. Pacientes (n=42) com no mínimo duas LCNC foram incluídos. LCNC foram randomizadas em dois grupos: controle (solução placebo) ou grupo teste (aplicação de CRX 2% por 60 s após o condicionamento e antes da aplicação do adesivo). Restaurações Classe V (n=169) foram realizadas com adesivo de condicionamento ácido total e resina composta, por 10 operadores treinados. Um examinador calibrado avaliou as restaurações após 1 semana (base) e 6 meses usando os critérios da FDI. O desfecho primário foi retenção das restaurações. A análise dos fatores associados à falha das restaurações foi conduzida com Teste Exato de Fisher (α=0,05). Após 6 meses de acompanhamento, 3,4% (IC 95% 1,3-7,3) das restaurações falharam. Não houve diferença estatística entre os grupos CRX e controle (p=0,920). Com relação às variáveis das cavidades, cavidades mais profundas (p=0,024), largas (p=0,004) e em formato de cunha (p=0,033) falharam mais. Ambos os tratamentos (CRX e controle) proporcionaram performance clínica aceitável das restaurações. O uso de CRX como coadjuvante na adesão à dentina não influenciou a retenção das restaurações Classe V após 6 meses de acompanhamento.
The aim of this study was to evaluate the effect of cariogenic challenge on the microtensile bond strength values (μTBS) of dentin pre-treated with chlorhexidine digluconate (CHX) or sodium hypochlorite (NaOCl). Thirty-six sound molars were selected and randomly assigned to 3 dentin pre-treatments (distilled water - control, 2% CHX and 10% NaOCl) and 4 aging protocols (24h control, biofilm without cariogenic challenge, biofilm with cariogenic challenge, and 18-month water storage). The same etch-and-rinse adhesive system and composite resin were used for all groups (n=30 beams). For the biofilm groups, dental microcosm biofilms originated from saliva of a healthy donor were grown on the samples with a defined medium enriched with mucin, with or without 10% sucrose, according to the group. After the experimental period, the microtensile test was performed. Data were analyzed with ANOVA followed by Tukey test (p<0.05). The pre-treatment did not influence μTBS for all aging conditions (p=0.188), but the type of aging affected the bond strength (p<0.001). Cariogenic challenge and water storage aging affected the bond stability resulting in a decrease of the μTBS, but the pre-treatments did not influence the μTBS
O objetivo neste estudo foi avaliar o efeito do desafio cariogênico na resistência de união (RU) da dentina pré-tratada com clorexidina (CRX) ou hipoclorito de sódio (NaOCl). Trinta e seis molares hígidos foram selecionados e randomizados de acordo com 3 pré-tratamentos dentinários (controle, CRX a 2% e NaOCl a 10%) e 4 protocolos de envelhecimento (controle 24h, biofilme sem desafio cariogênico, biofilme com desafio cariogênico, e armazenamento de 18 meses em água). O mesmo sistema adesivo e resina composta foram usados para todos os grupos (n=30). Biofilme dental de microcosmo originado da saliva de doador saudável foi desenvolvido sobre as amostras com meio enriquecido com mucina adicionada ou não com sacarose a 10%, de acordo com o grupo. Após o período experimental, o teste de microtração foi realizado. Os dados de microtração foram analisados com ANOVA a dois fatores e teste de Tukey (p<0,05). O pré-tratamento não influenciou os valores de RU para todos os protocolos de envelhecimento (p=0,188), porém o tipo de envelhecimento influenciou os valores de RU (p<0,001). O desafio cariogênico e o armazenamento em água afetaram a estabilidade adesiva resultando na diminuição dos valores de RU e o pré-tratamento não influenciou os valores de RU.
The aim of this study was to evaluate if clinical experience, whether in relation to length of practice time and/or level of specialization influences the dentist’s preference for using posts to restore endodontically treated teeth. A cross sectional study was carried out using a questionnaire with dentists (n = 276) in Pelotas, southern Brazil. Data were collected regarding clinical experience, post-graduate training, and variables related to restorations (posts/cements and use of rubber dam) for endodontically treated teeth. The data were submitted to a descriptive analysis and associations were tested. The response rate was 68%. Cast metal posts (24.53%), glass fiber posts (20.75%) and resin cement (66.67%) were the most commonly selected materials. In relation to rubber dams, 93.05% of the dentists were found not use them to lute posts. There was a significant association between the level of training of post-graduate dentists and the type of post used (p = 0.027), in that dentists without post-graduate training used cast metal posts more frequently, whereas dentists with post-graduate training reported glass fiber posts as their first choice. The results of the study showed that dentists preferred cast metal posts, glass fiber posts and resin cement. Continuing education influenced the decision of the dentists on their choice of dental posts.
The aims of this study were to evaluate the effect of immediate and delayed resin cement application on the microtensile bond strength of indirect composite resin restorations and, to evaluate adhesive strategies (for regular resin cement or humidity parameters for self-adhesive resin cement). Forty-five enamel/dentin discs (0.5 mm height and 10 mm of diameter) obtained from bovine teeth were divided into nine groups (n = 5). For regular cement, the variation factors were cementation technique at three levels (immediate cementation, 5 or 30 min after adhesive system application); and type of adhesive system at two levels (three- or two-step). For self-adhesive cement, the dentin moisture was the source of variation at three levels (normal, dry, or wet cementation). The specimens were submitted to microtensile bond strength (μTBS) testing using a universal testing machine. Data were analyzed by ANOVA, Tukey’s test, and linear regression. Regular cement and three-step etch-and-rinse adhesive system showed the highest values of bond strength (25.21 MPa–30 min of delay). Only for this condition, three-step adhesive showed higher bond strength than the two-step adhesive. Nevertheless, the linear regression showed that irrespective of the strategy, the use of the two-step approach when compared with three-step adhesive system decreased μTBS (p < 0.001). The failure analysis showed predominant adhesive failures for all tested groups. All groups had comparable values of bond strength to bovine dentin when the same materials were used, even in suboptimal clinical conditions.
This study aimed to identify factors that can affect the retention of glass fiber posts to intra-radicular dentin based on in vitro studies that compared the bond strength (BS) of GFPs cemented with resin cements. Searches were carried out in PubMed and Scopus until December 2013. Bond strength values and variables as type of tooth, presence of endodontic treatment, pretreatment of the post, type of bonding agent (if present), type of cement and mode of cement application were extracted from the 34 included studies. A linear regression model was used to evaluate the influence of these parameters on BS. The presence of endodontic treatment decreased the BS values in 22.7% considering the pooled data (p = 0.013). For regular cement, cleaning the post increased BS when compared to silane application without cleaning (p = 0.032), considering cleaning as ethanol, air abrasion, or phosphoric acid application. Applying the cement around the post and into root canal decreased the resistance compared to only around the post (p = 0.02) or only into root canal (p = 0.041), on the other hand, no difference was found for self-adhesive resin cement for the same comparisons (p = 0.858 and p = 0.067). Endodontic treatment, method of cement application, and post pretreatment are factors that might significantly affect the retention of glass-fiber posts into root canals mainly when cemented with regular resin cement. Self-adhesive resin cements were found to be less technique-sensitive to luting procedures as compared with regular resin cements.
This Communication aims to present the issue of dental erosion in another point of view. Considering the increasing rate of incidence of this dental injury among children and adults, the narrative raises the question about the danger of indiscriminate intake of certain acidic foods and beverages which are scientifically proven as one of the causes of dental erosion, as well as the complete neglect of information by the food industry about these products. The authors present some points that still remain in doubt in this topic and some approaches, which should be taken to alert the population about the relation between acidity of food and dental erosion.
El objetivo del presente estudio es abordar el tema de la erosión dental desde otro punto de vista. Al tener en cuenta la creciente tasa de incidencia de esta lesión dental en niños y adultos, el trabajo plantea la pregunta sobre el peligro de la ingesta indiscriminada de ciertos alimentos ácidos y bebidas que han sido identificados científicamente como una de las causas de la erosión dental, como asimismo, una completa falta de información por parte la industria alimentaria sobre estos productos. Se presentan algunos puntos que aún quedan en duda referente a este tema y algunos enfoques que se deben tomar para alertar a lapoblación acerca de la relación entre la acidez de los alimentos y la erosión dental.