Effect of strontium chloride-incorporated hypochlorous acid conditioner on bond performance to eroded dentine

The aim is to evaluate the effect of a strontium chloride-incorporated hypochlorous acid (Sr/HOCl) conditioner on bond performance in eroded dentine using self-etch adhesives.

Adhesive bonding to eroded dentine presents significant challenges owing to the compromised substrate ultrastructure, exposed collagen networks, and reduced resin infiltration, necessitating innovative pretreatment approaches.

Seventy-four caries-free molars were subjected to a 5-day erosive cycling using Coca-Cola. The specimens were randomly allocated to four groups based on the Sr/HOCl pretreatment and adhesive system: Clearfil SE Bond 2 (SEB) and Clearfil Universal Bond Quick (UBQ). Microtensile bond strength testing, failure mode analysis, scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS), and confocal laser scanning microscopy (CLSM) were conducted. Three-way ANOVA with Tukey post hoc comparisons, Chi-square test for failure modes, and t-test for elemental analysis (α =0.05).

UBQ with Sr/HOCl pretreatment significantly improved bond strength (P < 0.001), whereas SEB showed no significant changes (P > 0.05). Mixed failures were predominant across groups. EDS confirmed exclusive strontium incorporation into the treated specimens (P < 0.001), with preserved calcium and phosphorus levels. CLSM revealed reduced interface permeability and enhanced resin infiltration following Sr/HOCl treatment.

Sr/HOCl conditioning significantly enhanced the bonding to eroded dentine through organic component reduction, strontium deposition, and improved interface characteristics. This pretreatment particularly benefits simplified adhesive systems, suggesting its clinical potential for improving the durability of eroded substrates.