Shear Bond Strength of Ceramics to Chlorhexidine versus Pomegranate Peel Extract – Pretreated Dentin: A Randomized Control Study

Abstract

Background: Durable tooth bonding is the hallmark of successful minimally invasive all-ceramic restorations. Aim: The aim of this study was to assess the shear bond of ceramics to pretreated dentin with chlorhexidine (CHX) or pomegranate peel extract (PPE), compared to no pretreatment (control), after thermocycling. Materials and Methods: Thirty extracted sound human premolars were enrolled and mounted in autopolymerized acrylic blocks. Occlusal 3 mms were removed to obtain the flat dentin surfaces. Teeth were randomly distributed among three equal groups (n = 10) according to dentin pretreatment; (group I: No pretreatment (control), group II: 2% CHX, and group III: PPE pretreatments). Ceramic discs (4 mm × 4 mm × 1.5 mm) were milled from zirconia-reinforced lithium silicate (ZLS) blocks (Celtra Duo, Dentsply), and cemented to prepared teeth with self-adhesive cement (RelyX Unicem, 3M). All samples were thermocycled for 2500 cycles at 5°C–55°C. Shear bond strengths (SBSs) were assessed followed by statistical analysis using one-way ANOVA, followed by Tukey’s post hoc test. The significance level was set at P ≤ 0.05 in all tests. Results: CHX-pretreated group showed the best SBS (18.40 ± 1.27 MPa) after thermocycling, compared to control (12.24 ± 1.20 MPa) and PPE-pretreated groups (5.89 ± 0.24 MPa) with a statistically significant difference among all groups (P ≤ 0.05). Conclusions: In contrary to PPE, CHX-dentin pretreatment kept better SBS to ceramics after thermocycling, providing an access to minimally invasive, yet durable esthetic restoration.