In vitro-assessment of Ribose modified Universal Adhesive.

Description :

- Sound human molars (n=160; age range: 18–30 years) free from caries and restorations, extracted for periodontal reasons will be used in the study. - They will be cleaned with ultrasound to remove any substance adherent to the dental tissues and then preserved in a solution of de-ionized water and sodium azide (0.2%) at 4◦C to inhibit microbial growth and will be used within 1 month from the start of the experiments. - Teeth will then be coated in chemo-polymerizable acrylic resin. - The occlusal third of the tooth will be removed with a diamond disc at low speed under constant irrigation in order to expose the dentine. - Smear layer will be standardized by grinding the surface with 600 grit silicon carbide paper using the variable speed grinder-polisher (Buehler Ltd., Lake Bluff, IL, USA) at a motor speed 70 rpm for 1min under a water spray. - A commercial universal adhesive Prime and bond active (Dentsply) modified by ribose will be used in this study in a self-etching mode. N.B: The RB powder was added directly to the ethanol solvent with respect to the monomer and adhesives stored at 4°C. Methods: Dentine surfaces were bonded in vitro with commercial universal adhesive “ Prime and Bond active” modified with (0, 0.5%, 1% and 2% ribose), restored with restorative composite–resin, and sectioned into resin–dentine slabs and beams to be stored for 24 h in artificial saliva. Sectioned specimens with exposed dentine surfaces were randomly assigned to various groups. Group 1: Control group received adhesive (without modification). Group 2: Specimens were bonded with 0.5%RB modified universal adhesive Prime and Bond active (Dentsply) and immediately restored with composite resin. Group 3: Specimens were bonded with 1%RB modified universal adhesive Prime and Bond active (Dentsply) and immediately restored with composite resin. Group 4: Specimens were bonded with 2%RB modified universal adhesive Prime and Bond active (Dentsply) and immediately restored with composite resin. Bonding Procedure: - In order to completely wet the surface of dentine to be treated, an Applicator Tip to apply adhesive will be used. - The Applicator Tip will be rewet if necessary. - We will keep the adhesive away from pooling. - We will apply the adhesive in agitation for 20 seconds, and then removed solvent with clean, dry air from an air-water syringe until a glossy and uniform layer appears. - We will polymerize the adhesive using LED for 20s - We will apply resin composite (z250, 3M ESPE, St Paul, MN, USA) into 2 layers of 2 mm each one and we will polymerize using LED for 20s on each layer.