The effect of the titanium nitride coating on bacterial adhesion on orthodontic stainless steel wires: in vivo study

The aim of the current study was an in vivo evaluation of the bacterial adhesion on TiN coated orthodontic stainless steel wires in 20 patients (age15-25) undergoing fi xed orthodontic treatment who have the indication for placement of 0.019 ×0.0 25 inch Stainless steel arch wires in both jaws. TiN coatings were formed on orthodontic stainless steel wires by physical vapor deposition (PVD), Then the accuracy of the procedure was detected using SEM microscopy (PHILIPS XL 30) at ×2000 magnify. Each patient will serve as their own control, the coated arch wires will randomly be assigned to one jaw and the opposing jaw will receive a non-coated arch wires. After 4 weeks, the arch wires will be removed and cut at the same lengths (20mm). The samples were placed in sterile dishes containing phosphate buffered saline. After separation of bacteria in trypsin (25%) and ethylene di-amine teta-acetic solutions for 45 minutes, the diluted solution was cultured in blood agar and bacterial colony forming units were counted. According to the results, signifi cant difference detected on colony count on TiN coated orthodontic stainless steel wire (4 ± 3.4 ×104) compared to noncoated orthodontic stainless steel wire (8 ± 7.4 × 104) (P = 0.03). These results suggested that the TiN coated orthodontic stainless steel wire decreased bacterial growth and enhanced oral hygiene.