title: Effects of daily fluoride exposures on fluoride release by glass ionomer-based restoratives.
abstract: It is well documented that glass ionomer cements absorb and release fluoride following single fluoride exposures. This study examined fluoride release among three glass ionomer-based restorative materials following multiple daily exposures to three topical fluoride regimens. Using a Delrin mold, 32 cylindrical specimens, each of a glass ionomer (Ketac-Fil), resin-modified glass ionomer (Photac-Fil) and polyacid-modified resin (Dyract AP) were created. Each specimen was subjected to one of four daily treatments (n = 8): (1) no fluoride treatment (control); (2) application of a fluoride dentifrice (1000 ppm) for one minute once daily; (3) application of the same dentifrice for one minute twice daily; (4) the same regimen as (3), plus immersion in a 0.05% sodium fluoride (NaF) mouth rinse (225 ppm) for one minute immediately following the second dentifrice application. Each specimen was suspended in a polyethylene test tube containing 1.0 ml demineralizing solution (pH 4.3) at 37 degrees C for six hours, then transferred to a new test tube containing 1.0 ml remineralizing solution (pH 7.0) at 37 degrees C for 18 hours. Fluoride treatments were completed at the time of transfer daily for seven days. Media solutions were buffered with equal volumes of TISAB II; fluoride levels were measured using a digital ion analyzer and fluoride electrode. Fluoride release decreased significantly from Day 1 to Day 3 for all materials regardless of fluoride treatment (Repeated Measures ANOVA, Tukey HSD, p < 0.05). All specimens released significantly more fluoride in demineralizing solution than in remineralizing solution. For Days 2-7, Treatment 4 produced greater fluoride release than both the control and Treatment 2 for all three materials (p < 0.05); For each material, the fluoride release produced by Treatments 3 and 4 was statistically similar on most days throughout the study. By Day 7, Photac-Fil demonstrated both the greatest total fluoride release and the greatest rechargability, followed by Ketac-Fil and Dyract AP. Although subsequent daily fluoride release never approached that of Day 1, increasing daily fluoride exposures enhanced fluoride release for all three restorative materials.
authors.affiliation: Advanced Education in General Dentistry Program, Naval Dental Center, Jacksonville, FL, USA. RFreedman@ndcse.med.navy.mil
authors.forename: Rick
authors.initials: R
authors.lastname: Freedman
authors.forename: Kim E
authors.initials: KE
authors.lastname: Diefenderfer
mesh_terms: D000042:Absorption; D000085:Acetates / Q000737:chemistry; D000704:Analysis of Variance; D002021:Buffers; D002130:Calcium Phosphates / Q000737:chemistry; D002326:Cariogenic Agents / Q000737:chemistry; D002327:Cariostatic Agents / Q000737:chemistry*; D020770:Compomers / Q000737:chemistry; D003802:Dentifrices / Q000737:chemistry; D004058:Diffusion; D005459:Fluorides / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007101:Immersion; D008298:Maleates / Q000737:chemistry; D008422:Materials Testing; D009067:Mouthwashes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry; D012464:Saliva, Artificial / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry; D013997:Time Factors
chemical_list: D000085:Acetates; D002021:Buffers; D002130:Calcium Phosphates; D002326:Cariogenic Agents; D002327:Cariostatic Agents; D020770:Compomers; D003802:Dentifrices; C088486:Dyract; D005899:Glass Ionomer Cements; D008298:Maleates; D009067:Mouthwashes; C081144:Photac-Fil; D019279:Resin Cements; D012117:Resins, Synthetic; D012464:Saliva, Artificial; C040964:Ketac-Fil; D012969:Sodium Fluoride; D005459:Fluorides