Effect of sodium bicarbonate air abrasive polishing on resistance to sliding during tooth alignment and leveling: An in vitro study

Abstract

Objective: The aim of this in vitro study was to evaluate the Resistance to Sliding (RS) provided by metallic brackets and 3 types of orthodontic wires (TMA, SS and NiTi), before and after the use of sodium bicarbonate airborne particle abrasion, in an experimental model with 3 non leveled brackets. Materials and Methods: The bicarbonate airborne abrasion was applied perpendicularly to the bracket slots at a distance of 2 mm, for 5 seconds (T2) and 10 seconds (T3) on each bracket slot. In a universal testing machine, the wires were pulled through a set of 3 non leveled brackets at a cross head speed of 50 mm/min for a distance of 10 mm, and static and kinetic friction readings were registered at T1 (no airborne abrasion), T2 and T3. Results: For all tested wires, a significant RS increase between T1 and T3 (P<0.001) was seen. For SS and TMA wires, there was a statistically significant RS increase between T1 and T2 (P<0.001). Between T2 and T3, RS increase was significant for TMA (P<0.001) and NiTiwires (P<0.05). Conclusions: Sodium bicarbonate air abrasive polishing during orthodontic treatment is not recommended, once this procedure promoted a significant RS increase between the metallic brackets and all the three types of wires tested.