Rubbing time and bonding performance of one-step adhesives to primary enamel and dentin

Abstract

Objectives:This study investigated whether increasing the concentration of acidic monomers in one-step adhesives would allow reducing their application time without interfering with the bonding ability to primary enamel and dentin.Material and methods:Experimental one-step self-etch adhesives were formulated with 5 wt% (AD5), 20 wt% (AD20), or 35 wt% (AD35) acidic monomer. The adhesives were applied using rubbing motion for 5, 10, or 20 s. Bond strengths to primary enamel and dentin were tested under shear stress. A commercial etch-and-rinse adhesive (Single Bond 2; 3M ESPE) served as reference. Scanning electron microscopy was used to observe the morphology of bonded interfaces. Data were analysed at p<0.05.Results:In enamel, AD35 had higher bond strength when rubbed for at least 10 s, while application for 5 s generated lower bond strength. In dentin, increased acidic monomer improved bonding only for 20 s rubbing time. The etch-and-rinse adhesive yielded higher bond strength to enamel and similar bonding to dentin as compared with the self-etch adhesives. The adhesive layer was thicker and more irregular for the etch-and-rinse material, with no appreciable differences among the self-etch systems.Conclusion:Overall, increasing the acidic monomer concentration only led to an increase in bond strength to enamel when the rubbing time was at least 10 s. In dentin, despite the increase in bond strength with longer rubbing times, the results favoured the experimental adhesives compared to the conventional adhesive. Reduced rubbing time of self-etch adhesives should be avoided in the clinical setup.

Impact of pH and application time of meta-phosphoric acid on resin-enamel and resin-dentin bonding

“…A longer application time promoted more dissolution of the smear layer on the dentin surface for resin monomer diffusion, allowing mechanical interlocking (Botelho et al, 2017;Reis et al, 2013Reis et al, , 2008, and consequently higher resin-dentin μTBS for MPA and OPA. On the other hand, these voids could be not completely infiltrated by resin monomers (Hashimoto et al, 2000(Hashimoto et al, , 2002b.…”

Adezi̇v Uygulama Süresi̇ni̇n Uzatilmasinin Makaslama Bağlanma Dayanimi Üzeri̇ne Etki̇si̇

“…13 Buna karşın adezivlerin uygulama süresinin uzatılmasının bağlanma dayanımı üzerine etkisinin araştırıldığı çalışma sayısı oldukça azdır. [14][15][16][17] Bu in vitro çalışmanın amacı; üniversal adezivlerin uygulama zamanlarının uzatılmasının, makaslama bağlanma dayanımı üzerine etkisinin araştırılmasıdır. Çalışmamızın sıfır hipotezi; adeziv uygulama süresinin uzatılmasının makaslama bağlanma dayanımına etkisi olmadığı şeklindedir.…”