Evaluation of the association between marginal leakage and caries adjacent to dental restorations

Orientador: Jaime Aparecido CuryTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: Cárie secundária é considerada a principal causa para a substituição de restaurações, e tem sido atribuída à microinfiltração ao longo das interfaces restauradoras. No entanto, além de não haver clara associação entre microinfiltração e essas lesões, essa associação poderia ser irrelevante se fluoreto (F) estivesse presente nessas interfaces. Portanto, este estudo in situ objetivou avaliar o efeito de microinfiltração em cárie adjacente a restaurações em presença de F, tanto individualmente fornecido por material restaurador ou dentifrício fluoretado como associado a partir dessas fontes. O estudo foi realizado em 4 fases de 14 dias cada. Os fatores em avaliação foram material restaurador em 2 níveis: RC ¿ resina composta, e CIV ¿ cimento de ionômero de vidro modificado por resina; condição de infiltração marginal em 2 níveis: L- -sem indução de infiltração, e L+ - com indução de infiltração; e tratamento com F em 2 níveis: DNF ¿ dentifrício não fluoretado (placebo), e DF ¿ dentifrício fluoretado. Da associação destes fatores foram obtidos subgrupos, os quais foram aleatoriamente designados aos voluntários (n=14). Durante todas as fases experimentais, foi permitido o acúmulo de biofilme sobre os blocos restaurados sendo esses submetido a um alto desafio cariogênico pela exposição a uma solução de sacarose 20%, 10x/dia, o que foi feito extra-oralmente. Os voluntários usaram três vezes por dia os dentifrícios DNF ou DF, dependendo da fase experimental. Não foram encontradas diferenças entre restaurações L+ e L-, considerando todas as variáveis estudadas (p>0.05). Maior desmineralização em esmalte e em dentina foi observada adjacente a restaurações de RC do que adjacente a restaurações de CIV quando DNF foi usado (p0.05). Higher demineralisation in both enamel and dentine around RC restorations than around GI restorations was observed under NF dentifrice use (p<0.05). F concentration was higher in the fluid of biofilm exposed to FD or formed onto GI restoration (p<0.05). It can be concluded from the results that microleakage has no influence on secondary caries in the presence or absence of F from dentifrices or restorative materials, and that the presence of F in the biofilm provided by GI and/or FD is important to inhibit demineralisation adjacent to restorations.DoutoradoCariologiaDoutor em Odontologi

Effect of cariogenic challenge on the stability of dentin bonds

Objective: The oral environment is subject to biofilm accumulation and cariogenic challenge, and few studies exist on the effect of these factors on the bond strength of adhesive systems. The aim of this study was to test if the exposure of adhesive interfaces to cariogenic challenge under biofilm accumulation could promote higher degradation than the exposure to biofilm accumulation alone. Material And Methods: Five molars were ground until exposure of medium dentin and then restored (Single Bond 2 and Z250 3M ESPE). The tooth/resin sets were cut to obtain beam-shaped specimens, which were distributed according to the aging conditions (n=20): water for 24 h (control); biofilm under cariogenic challenge for 3, 5 or 10 days; biofilm without cariogenic challenge for 10 days; and water for 3 months. Microcosm biofilms were formed from human saliva and grown in a saliva analogue medium, supplemented or not with sucrose to promote cariogenic challenge. Specimens were tested for microtensile bond strength, and failure modes were classified using light microscopy. Bond strength data were analyzed using ANOVA and failure modes were analyzed using ANOVA on ranks (α=0.05). Results: No significant differences in bond strength were detected among the aging methods (P=0.248). The aging period was associated with an increase in the frequency of adhesive failures for the groups aged for 10 days or longer (

Coroa VS compósito para restauração de dentes tratados endodonticamente

O principal objetivo desse estudo foi comparar a sobrevivência de dentes e sucesso de restaurações em tratamentos endodônticos com estrutura dentária remanescente, que recebeu pino de fibra de vidro e foram restaurados com resinas compostas ou coroas metalocerâmicas em um estudo clínico randomizado

Transparency in clinical trials: Adding value to paediatric dental research

Background Even though considered as studies with high methodological power, many RCTs in paediatric dentistry do not have essential quality items in their design, development, and report, making results’ reliability questionable, replication challenging to conduct, wasting time, money, and efforts, and even exposing the participants to research for no benefit. Aim We addressed the main topics related to transparency in clinical research, with an emphasis in paediatric dentistry. Design We searched for all controlled clinical trials published from January 2019 up to July 2020 in the three paediatric dentistry journals with high journal Impact Factor, indexed on Medline. These papers were assessed for transparency according to Open Science practices and regarding reporting accuracy using some items required by CONSORT. Results 53.6% of the studies declared registration, 75% had sample size calculation, 98.2% reported randomisation, and from those, 65.4% explained the randomisation method. Besides that, no study shared their data, and 6.8% were published in open access format. Conclusions Unfortunately, a large proportion of RCTs in paediatric dental research show a lack of transparency and reproducibility

Quando deve ser realizado o tratamento odontológico pré-oncológico?: uma revisão rápida da literatura

O objetivo deste estudo foi determinar, por meio de uma revisão rápida da literatura, a influência de diferentes tempos para procedimentos odontológicos rea-lizados em pacientes com CCP antes da radioterapia e/ou quimioterapia no risco de desenvolvimento de complicações bucais

New material perspective for endocrown restorations: effects on mechanical performance and fracture behavior

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 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

Research integrity practices: A Pre-Post Study with Brazilian Graduate Students

This study aims to evaluate the impact of an educational intervention in increasing the adhesion and awareness of Master's and Ph.D. candidates at a Southern Brazilian University to research integrity and open science practices

Effects of modeling liquid/resin and polishing on the color change of resin composite

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