Reduction in erosive tooth wear using stannous fluoride-containing dentifrices: a meta-analysis

Abstract Dentifrices containing different active agents may be helpful to allow rehardening and to increase the resistance of the eroded surface to further acids or mechanical impacts. This study aimed to compare the effects of conventional (sodium fluoride [NaF]) and stannous fluoride (SnF2)-containing dentifrices on reducing erosive tooth wear (ETW). The PubMed/MEDLINE, Scopus, LILACS, BBO, EMBASE, TRIP electronic databases, and grey literature were searched until January 2021 to retrieve relevant in vitro and in situ studies related to research question. There were no restrictions on publication year or language. Two authors independently selected the studies, extracted the data, and assessed the risk of bias. ETW data were pooled to calculate and compare both dentifrices (overall analysis) and in vitro and in situ studies separately (subgroup analysis). Statistical analyses were performed using RevMan5.3 with a random effects model. Of 820 potentially eligible studies, 101 were selected for full-text analysis, and 8 were included in the systematic review and meta-analysis. There was a significant difference between SnF2-containing dentifrices and NaF dentifrices only for in vitro studies (p=0.04), showing a higher effect of the SnF2-containing dentifrices against the erosion/abrasion (effect size: -6.80 95%CI: -13.42; -0.19). Most in vitro and in situ studies had high and low risk of bias, respectively. In vitro literature suggests that the ETW reduction is greater when using SnF2-containing dentifrices instead NaF-containing dentifrices. However, the evidence level is insufficient for definitive conclusions. Clinical trials are necessary for a better understanding of the effect of these compounds on ETW.

Como reparar uma restauração oclusal de resina composta em dentes decíduos? Relato de caso / How to repair an occlusal composite resin restoration on primary teeth? Case report

Frente à necessidade de reintervenção em restaurações insatisfatórias, os clínicos podem, em geral, optar pela substituição ou reparo. Este artigo relata um caso clínico de reparo de uma restauração de resina composta com falha em dente decíduo. Após profilaxia e isolamento relativo, a porção da resina composta a ser reparada foi asperizada com uma ponta diamantada em alta rotação com o intuito de melhorar a união mecânica entre a resina envelhecida e a nova (reparo). Foi realizado o condicionamento com gel de ácido fosfórico a 34% por 15 segundos, seguido de lavagem e secagem. Uma camada do sistema adesivo Single Bond Universal (3M ESPE) foi aplicada ativamente durante 20 segundos, seguido de jato de ar comprimido por 5 segundos e fotoativação por 10 segundos. Por fim, a resina composta fluida (Filtek Z350 XT Flow; 3M ESPE) foi inserida e fotoativada por 20 segundos. A realização de um adequado protocolo clínico envolvendo tratamentos físicos e químicos de superfície é fundamental para a efetividade da intervenção e a manutenção do dente decíduo clinicamente funcional até a esfoliação fisiológica.

Facing need for reintervention in unsatisfactory resto-rations, clinicians may generally choose for replacement or repair. This paper reports a clinical case of repair of a composite resin restoration with failure in primary tooth. After prophylaxis and relative isolation, the portion of the composite resin to be repaired was roughed with a high-speed diamond bur to improve the mechanical bond between the aged and new resin (repair). Conditioning with 34% phosphoric acid gel was performed for 15 seconds, followed by washing and drying. One layer of the adhesive system Single Bond Universal (3M ESPE) was actively applied for 20 seconds and light- cured for 10 seconds. Finally, the flowable composite resin (Filtek Z350 XT Flow; 3M ESPE) was inserted and light-cured for 20 seconds. An adequate clinical protocol involving physical and chemical surface treatments is essential for the effectiveness of the intervention and the main-tenance of the primary tooth clinically functional until physiological exfoliation.

Does use of silane-containing universal adhesive eliminate the need for silane application in direct composite repair?

Abstract This in vitro study aimed to evaluate the effect of a silane-containing universal adhesive used with or without a silane agent on the repair bond strength between aged and new composites. Forty nanohybrid composite resin blocks were stored in distilled water for 14 d and thermo-cycled. Sandpaper ground, etched, and rinsed speciments were randomly assigned into four experimental groups: silane + two-step etch-and-rinse adhesive system, two-step etch-and-rinse adhesive system, silane + silane-containing universal adhesive system, and silane-containing universal adhesive system. Blocks were repaired using the same composite. After 24 h of water storage, the blocks were sectioned and bonded sticks were submitted to microtensile testing. Ten unaged, non-repaired composite blocks were used as a reference group to evaluate the cohesive strength of the composite. Two-way ANOVA and Tukey's tests were used to analyze average µTBS. One-way ANOVA and Dunnet post-hoc tests were used to compare the cohesive strength values and bond strength obtained in the repaired groups (α = 0.05). The µTBS values were higher for the silane-containing universal adhesive compared to the two-step etch-and-rinse adhesive system (p = 0.002). Silane application improved the repair bond strength (p = 0.03). The repair bond strength ranged from 39.3 to 65.8% of the cohesive strength of the reference group. Using universal silane-containing adhesive improved the repair bond strength of composite resin compared to two-step etch-and-rinse adhesive. However, it still required prior application of a silane agent for best direct composite resin repair outcomes.