Do Restorative Strategies and Delayed Restoration Improve the Bond Strength to Biodentine? In Vitro Study on Adhesive...

The popularity of Biodentine (Septodont) use for vital pulp therapies requires verifying its bonding ability to other restorative materials. The null hypotheses were that different restorative materials and adhesive strategies did not influence shear bond strength (SBS) to Biodentine, nor its setting time.

204 plastic molds were filled with Biodentine, half set for 12 min, and the rest for 7 days. Specimens were divided into six groups according to the strategy and material used to restore over Biodentine (n = 17): (1) SE: Universal adhesive application in self-etch mode; (2) ER: Universal adhesive in etch-and-rinse mode; (3) Bur: Roughening with a bur followed by SE; (4) AO: Airborne-particle abrading with Al2O3 particles before SE; (5) RMGIC: Restoration with a resin-modified glass-ionomer; (6) SARC: Restoration with a self-adhesive resin cement. Groups 1 to 4 were restored with a flowable bulk-fill composite. Specimens were subjected to SBS, and the mode of failure was determined. Five additional specimens were evaluated under SEM-EDX. Data were analyzed with Kruskal-Wallis and U-Mann-Whitney tests (P 0.05).

AO and SARC groups showed 100% pretest failures. At 12 min setting, the RMGIC group and Bonferroni correction achieved the lowest SBS values. At a 7-day setting, the Bur group registered the lowest SBS, and the groups restored with universal adhesive achieved the highest values. SBS results for the Bur and RMGIC groups were influenced by the setting time.

Bur roughening or alumina airborne-particle abrading did not improve Biodentine adhesion to composite resin restorations, whereas the application of a universal adhesive achieved the highest SBS results regardless of the evaluated setting time.