Optimization of direct currents to enhance dentine bonding of simplified one‐step adhesive

Abstract

The aim of this study was to investigate the effects of different direct current intensities on dentine bonding effectiveness of Clearfil S(3) Bond and on cell viability of human dental pulp cells (HDPCs). Thirty-five-third molars were sectioned and ground to provide flat surfaces. Clearfil S(3) Bond was applied under different current conditions for 30 s and then resin composite was built up. Specimens were processed for microtensile bond strength (µTBS) testing and for nanoleakage investigation using scanning electron microscopy. Primary HDPCs isolated from premolars were stimulated with different intensities of electric current for 30 s. Then, cell viability was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Specimens bonded with application of electrical current intensities of 50, 60, 70, and 90 µA exhibited a significant increase in immediate µTBS compared with all other groups. Bonded interfaces prepared using electrically assisted current application showed reduced interfacial nanoleakage upon scanning electron microscopy. Electric current application, from 20 to 70 µA, had no effect on the viability of HDPCs. This study provides further evidence for its future clinical use.

Adhesive systems applied to dentin substrate under electric current; systematic review

“…Some studies cite [ 13 15 16 18 19 20 21 22 23 ] or refer [ 14 24 ] the intensity of the applied electric current. One single paper concerned the application of the electricity-assisted technique to evaluate the pulp cell vitality [ 18 ].…”

“…Some studies cite [ 13 15 16 18 19 20 21 22 23 ] or refer [ 14 24 ] the intensity of the applied electric current. One single paper concerned the application of the electricity-assisted technique to evaluate the pulp cell vitality [ 18 ]. The other works evaluated in vitro the human tooth-restoration bond strength submitted to mechanical trials [ 3 14 15 18 19 21 22 23 24 ], the contact angle [ 14 16 ] formed by the adhesive and the tooth and/or carried out qualitative analyses in microscopy [ 3 13 14 15 16 18 19 22 23 24 ], as described in Table 1 .…”

“…The studies which performed resin composite restorations on dentin used micro-hybrid materials [ 3 13 15 16 18 19 20 21 22 23 24 ]. Only the researches by Barcellos [ 21 ] and Gotti et al .…”

“…The study carried out by Chen et al . [ 18 ] states that when applying the electric current on pulp cells, their vitality is only preserved if the electric current is up to 70 µA. However, laboratory studies for dentin-restoration bond strength evaluation have used electric currents as high as 110 µA [ 13 ].…”

Influence of a heating device and adhesive temperature on bond strength of a simplified ethanol-based adhesive system

“…The interaction between dentin and resin monomers depends on surface conditioning 2 , and optimal dentin bonding occurs when adhesive monomers infiltrate completely into the mineralized dentin fibril network after etching 3 . Procedure changes have been suggested to improve bonding performance 4,5 .…”