Acid-etching protocol for bioceramic cements: Evaluation of bond strength, compression and morphology

To establish an acid-etching protocol for Biodentine and Cimmo DTA, evaluating compressive strength, bond strength, surface morphology in scanning electron microscope and failure modes after different etching times. Two test specimens were prepared for each cement and divided into four groups (n = 12) according to the acid-etching time (0, 5, 10 and 15 s). Compressive strength was tested using a universal testing machine, while bond strength was evaluated after bonding with Filtek Bulk Flow resin using Universal ESPE Single Bond adhesive. Failures were classified as surface-adhesive, cement-cohesive, resin-cohesive and mixed. Biodentine showed significantly higher compressive strength than Cimmo DTA (p < 0.001), regardless of acid etch time (p < 0.001). Different acid-etching strategies are required for Biodentine and Cimmo DTA, with Biodentine requiring selective etching and Cimmo DTA requiring a full 15-s etch to optimise bond strength properties.