Titanium nitride doped with calcium phosphate alters surface of orthodontic brackets, Finds study

The research is published in the American Journal of Orthodontics and Dentofacial Orthopedics.

The goal of this research was to experimentally evaluate the surface morphology and adhesion capacity of Streptococcus mutans (U159) on brackets with thin films of titanium nitride (TN) and of titanium nitride doped with calcium phosphate (TNCP).

Licia Pacheco Teixeira and colleagues from the Clinical Dentistry Program, Federal University of Espirito Santo, Brazil conducted the study in which twenty-four metallic brackets were equally allocated to 3 groups of eight each, according to the type of covering (no covering, titanium nitride doped with calcium phosphate, and titanium nitride).

The coatings were deposited by cathodic cage (titanium nitride doped with calcium phosphate and titanium nitride groups) and were evaluated by scanning electron microscopy and energy dispersive x-ray spectrometry.

The biofilm formation of S. mutans on the surface of brackets was determined by crystal violet assay and subsequent optical density quantification.

The study showed that there was homogeneity on the surface morphology of the tie wing area in all groups, whereas the titanium nitride doped with calcium phosphate group has presented particles in the slot.

After 24 hours, a biofilm of S. mutans was formed in all the observed groups. The optical density obtained in all 3 groups was similar (no covering, 0.347 ± 0.042; titanium nitride doped with calcium phosphate, 0.238 ± 0.055; titanium nitride, 0.226 ± 0.057), with no statistically relevant difference (P = 0.06).

Hence, the researchers concluded that "the thin film of titanium nitride doped with calcium phosphate has altered the surface of the bracket's slot, whereas the coatings of titanium nitride and titanium nitride doped with calcium phosphate have not altered the superficial morphology of the tie wings."

The presence of coatings have not influenced the formation of the S. mutans biofilm on the surface of metallic brackets, they further added.