Evaluation of Static Friction of Polycrystalline Ceramic Brackets after Conditioning with Different Powers of Er:YAG Laser

Figure 2

Schematic of universal testing machine. To measure the friction between the wire and bracket, a universal testing machine (SANTAM) (Sahand Company, Iran) was used. Straight line static traction test was carried out by this machine to simulate sliding of wire in the bracket. At one end of the machine there was an aluminum device that was attached to a 50 N load cell; this machine included two plates. The brackets were bonded to the lower stable plate. The wire was attached to the upper plate and then engaged in the bracket by elastomeric ligation; the wire was pulled out of the slot of the bracket with 50 N load cell at a rate 1 mm/min.