Effect of topical fluoride agents on the morphologic characteristics and composition of resin composite restorative materials.
BACKGROUND
The high reactivity of fluoride agents used in topical fluoride treatments have raised important questions on their potential adverse effects on restorative materials.


OBJECTIVE
The purpose of this study was to evaluate the effect of topical fluoride agents used for office or home treatments on the surface morphologic characteristics and composition of composite restoratives.


METHODS
The fluorides used were Act, Phosflur, Gel II, Prevident, Stop, Butler APE, Nupro, and Omni Gel & Rinse. The composites tested were Brilliant DI, Heliomolar Ro, Herculite XRV, and P-50. The pH of the fluorides was measured as received and after dilution with water at a 1:3 volume ratio. The composites were subjected to the fluoride treatments until the total number of applications simulated the equivalent of 4 years under treatment. The changes induced on the surface morphologic features and composition of the restoratives were assessed by multiple internal reflectance Fourier transform infrared spectroscopy, scanning electron microscopy, and x-ray microanalysis.


RESULTS
All fluorides showed an acidic pH that was not significantly changed after dilution, except Stop, which exhibited a significant pH reduction. All fluorides increased the amount of loosely bound water in the composite matrix. Butler APF gel was the most aggressive for Brilliant DI and Herculite XRV, leading to excessive surface degradation, porosity, destruction of the filler-matrix interface, filler dissolution, and debonding. A reduction in the extent of remaining C = C bonds was observed in Herculite XRV after Butler APF treatment; Phosflur, Gel II, and Prevident had a milder effect. Treatment of Brilliant Dl and Herculite XRV with Omni Gel & Rinse resulted in the formation of a stable precipitation layer rich in barium, phosphorus, tin, oxygen, and fluoride. P-50 was severely affected at the resin-matrix interface after Stop treatment, whereas Omni Gel & Rinse induced fewer surface changes. Heliomolar Ro was the least affected restorative regardless of the type of fluoride used.
Papagiannoulis
L
L
Department of Pediatric Dentistry, University of Athens, School of Dentistry and Research Center for Biomaterials, Greece.
Tzoutzas
J
J
Eliades
G
G
D000149:Acidulated Phosphate Fluoride / Q000737:chemistry; D000180:Acrylic Resins / Q000737:chemistry; D001464:Barium / Q000032:analysis; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002327:Cariostatic Agents / Q000737:chemistry*; D055598:Chemical Phenomena; D011232:Chemical Precipitation; D002627:Chemistry, Physical; D003188:Composite Resins / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D003802:Dentifrices / Q000737:chemistry; D004577:Electron Probe Microanalysis; D005459:Fluorides / Q000032:analysis; D005460:Fluorides, Topical / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009067:Mouthwashes / Q000737:chemistry; D010100:Oxygen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D011140:Polyurethanes / Q000737:chemistry; D016062:Porosity; D019279:Resin Cements / Q000737:chemistry; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014001:Tin / Q000032:analysis; D014867:Water
D000180:Acrylic Resins; D002327:Cariostatic Agents; C029012:Composite Dental Resin; D003188:Composite Resins; D003802:Dentifrices; D005460:Fluorides, Topical; D005782:Gels; C513708:Heliomolar; D009067:Mouthwashes; D011140:Polyurethanes; D019279:Resin Cements; D014867:Water; C065770:Herculite XR; C065771:P50 composite resin; C069353:Brilliant Dentin resin; D001464:Barium; D010758:Phosphorus; D000149:Acidulated Phosphate Fluoride; D017438:Bisphenol A-Glycidyl Methacrylate; D014001:Tin; D005459:Fluorides; D010100:Oxygen