Effect of silver antibacterial agents on bond strength of fiber posts to root dentin

Abstract This study was conducted to evaluate whether antibacterial pretreatment irrigation with silver nanoparticles (SNPs) and silver diamine fluoride (SDF) has any effect on bond strength of fiber posts cemented with three types of resin cements in root canal space. Fifty-four endodontically treated maxillary central incisor roots were prepared for fiber post (FRC Postec Plus NO.3, Ivoclar Vivadent) cementation and divided into nine groups in terms of three cement types and two pretreatments with silver antibacterial agents. The cements were as follows: an etch-and-rinse cement (ER, Excite DSC/Variolink N), a self-etch cement (SE, ED Primer/Panavia F2.0), and a self-adhesive cement (SA, Panavia SA Luting Plus). For each cement, the control group was with no treatment and two experimental groups were with SNPs and SDF treatments that were used after acid-etching for ER cement and after EDTA treatment for SE and SA cements. After fiber post cementation, each bonded root was horizontally sectioned into 1-mm thickness microslices to create two slices for each root region (apical, middle and coronal) and underwent push-out bond strength (PBS) test. Data in MPa were analyzed with two-way ANOVA and Tukey test (p=0.05). The interaction of the pretreatment type and cement type was significant (p<0.001). SNPs and SDF significantly increased PBS with ER cement (p≤0.04). This positive effect was also marginally significant for SDF with SE cement (p=0.049). For SA cement, SNPs showed a significant positive effect, but SDF had a significant adverse effect on PBS (p<0.001). The effect of pretreatment with silver antibacterial agents prior to adhesive cementation of fiber posts depends on the resin cement used. Contrary to SNPs with beneficial or no significant effect on bonding for all cements, SDF exhibited a deleterious effect with self-adhesive cement.

Resumo Este estudo foi conduzido para avaliar se a irrigação de pré-tratamento antibacteriano com nanopartículas de prata (SNPs) e fluoreto de diamina de prata (SDF) tem algum efeito na resistência de união de pinos de fibra cimentados com três tipos de cimentos resinosos no espaço do canal radicular. Cinquenta e quatro raízes de incisivos centrais superiores tratadas endodonticamente foram preparadas para cimentação de pino de fibra (FRC Postec Plus NO.3, Ivoclar Vivadent) e divididas em nove grupos em termos de três tipos de cimento e dois pré-tratamentos com agentes antibacterianos de prata. Os cimentos foram os seguintes: um cimento etch-and-rinse (ER, Excite DSC / Variolink N), um cimento autocondicionante (SE, ED Primer / Panavia F2.0) e um cimento autoadesivo (SA, Panavia SA Luting Plus). Para cada cimento, o grupo controle foi sem tratamento e dois grupos experimentais foram com SNPs e SDF tratamentos que foram usados após o condicionamento ácido para o cimento ER e após o tratamento com EDTA para os cimentos SE e SA. Após a cimentação do pilar de fibra, cada raiz ligada foi seccionada horizontalmente em microclimas de 1 mm de espessura para criar duas fatias para cada região da raiz (apical, média e coronal) e submetida ao teste de resistência de união por push-out (PBS). Os dados em MPa foram analisados ​​com ANOVA de dois fatores e teste de Tukey (p = 0,05). A interação do tipo de pré-tratamento e tipo de cimento foi significativa (p<0,001). SNPs e SDF aumentaram significativamente o PBS com cimento ER (p≤0,04). Este efeito positivo também foi marginalmente significativo para SDF com cimento SE (p = 0,049). Para o cimento SA, os SNPs mostraram um efeito positivo significativo, mas o SDF teve um efeito adverso significativo no PBS (p <0,001). O efeito do pré-tratamento com agentes antibacterianos de prata antes da cimentação adesiva dos pinos de fibra depende do cimento resinoso utilizado. Ao contrário dos SNPs com efeito benéfico ou nenhum efeito significativo na adesão para todos os cimentos, o SDF exibiu um efeito deletério com o cimento autoadesivo.

Effect of repeated use on dentin bond strength of two adhesive systems: All-in-one and one-bottle.

Aims: To compare the effects of repeated use of two one-bottle adhesives with that of two all- in- one adhesives (with acetone solvent) on bond strength to dentin. Materials and Methods: A flat dentin surface was prepared on 120 bovine incisors using 600- grit abrasive pape. The teeth were randomly assigned into 12 equal groups. The four adhesive systems [Prime and Bond NT (P&B NT), One-Step Plus (OS), iBond (iB), and G-Bond (GB)] were used at baseline, after the lid of the container had been opened 30 times, and after it had been opened 60 times. Before each use of the adhesives, the lids of the containers were left open for 1 min. The resin composites were applied on the dentin in a cylindrical split mold. After thermocycling, shear bond strength test was performed with a universal testing machine at 1 mm/min. We used Kruskal-Wallis and Dunn tests for statistical analysis. Results: There was no statistically significant difference among bond strength (MPa) of the groups of P&B NT (31.9 ± 4.6, 31.8 ± 6.5, 26.1 ± 6.7) and OS (33.2 ± 5.1, 30.9 ± 7, 29.3 ± 5.9), respectively (P > 0.05). The mean of the bond strength of iB and GB after 60 times (15.3 ± 4.1 and 12.2 ± 3.9, respectively) was significantly lower than that of iB and GB at baseline (23.5 ± 4.8 and 22.2 ± 4.5, respectively) (P < 0.05). Conclusions: Repeated use (60 times) of the all-in-one adhesive led to a decline in the dentin bond strength. To avoid this problem it would be advisable to have containers with smaller amounts of adhesive or perhaps those with only a singe dose.