Effect of a two-year fluoride decay protection protocol on titanium brackets.
BACKGROUND
Fluoride ion can attack titanium, causing its corrosion. Orthodontic patients being high-risk caries developers and in need of fluoride protection, the Center for Disease Control has developed a Fluoride Decay Prevention (FDP) protocol, consisting of a 6-minute tooth-brushing, followed by a 1-minute daily mouthwash, in addition to an in-clinic trimestrial topical fluoride gel application. This study aimed at evaluating gravimetrically, by scanning electron microscopy (SEM), and by sliding mechanics analysis, the consequences of FDP at 6, 12, 18, and 24months on titanium brackets corrosion.


METHODS
One hundred and fifty titanium brackets were randomly divided into five groups of 30. Group 1 was the control group. Groups 2, 3, 4, and 5 each received an equivalent of 6, 12, 18, and 24months of FDP treatment respectively. All groups were placed in artificial saliva for 2months and then rinsed. Subsequently, the brackets were dried, for 48hours, using Silica gel in a desiccator maintained at 37°C before testing.


RESULTS
SEM analysis showed that numbers and dimensions of pits gradually increased due to corrosion as we moved from group 1 to group 5. Gravimetrical and sliding mechanics results revealed no statistical difference between groups 2 and 3, and a significant difference between groups 4 and 5 upon comparison with the control group.


CONCLUSIONS
Surface changes due to corrosion were detected at 6 and 12months of FDP but had no clinical effects. However, the increase in sliding resistance and bracket weight loss became significant at 18 and 24months of FDP.
Department of Orthodontics, School of Dentistry, Saint Joseph University, Beirut, Lebanon.
Elie S
ES
Khoury
Maher
M
Abboud
Nayla
N
Bassil-Nassif
Joseph
J
Bouserhal
D000149:Acidulated Phosphate Fluoride / Q000737:chemistry; D003343:Corrosion; D005459:Fluorides / Q000737:chemistry*; D017276:Friction; D005782:Gels; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009067:Mouthwashes; D016910:Orthodontic Brackets; D011897:Random Allocation; D012464:Saliva, Artificial; D012969:Sodium Fluoride / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D014099:Toothbrushing
D005782:Gels; D009067:Mouthwashes; D012464:Saliva, Artificial; D000149:Acidulated Phosphate Fluoride; D012969:Sodium Fluoride; D014025:Titanium; D005459:Fluorides