Effects of Ultrasonic Instruments on Enamel and Dentine Surface Bonding.

Objectives: compare the bonding strength of porcelain to both enamel and dentine preparations finished with either ultrasonic instruments or finishing diamond burs as well as the effect of etching and no etching.
Methods: 60 extracted bovine teeth will be divided into 2 groups: A and B with 30 bovine teeth each. Each tooth will have 4 preparations on their buccal surface. In group A, 4 preparations limited to the enamel will be created with silicone carbide discs. Out of the 4 preparations, 2 will be finished with ultrasonic instruments (Perfect Margin Shoulder (PMS) Kit, Satelec, Merignac, France) while the remaining 2 enamel preparations will be finished with finishing diamond burs.
In group B, 4 preparations extending into dentine will be carried out with silicone carbide discs and similar methods of fine finishing will be carried out with either ultrasonic instruments or finishing diamond burs. For each tooth in group B, 1 preparation finished with finishing diamond burs and 1 preparation finished with PMS will undergo 3 step etch, prime and bond while the remaining 2 will be rinsed, primed and bonded. (Scotchbond^TM Multi-Purpose Adhesive System)
All the enamel preparation will be etched, primed and bonded accordingly.
Lithium disilicate ceramic veneers will be prepared and surface treatment will be carried out on the fitting surface, followed by cementation with resin luting agent according to the manufacturer’s recommendation. Tensile testing will be carried out with a universal testing machine with crosshead speed of 0.5mm/s and a load cell of 50N to compare the bonding of porcelain to both enamel and dentine preparations finished with the 2 different techniques and with or without acid etching.
Force at which failure occur will be converted to MPa for comparison and linear mixed model will be carried out to analyze the data.
Results: None yet
Conclusions: None yet