Fluoride release/uptake of polyacid-modified resin composites (compomers) in neutral and acidic buffer solutions.
The aim of the present study was to evaluate the fluoride uptake/release of polyacid-modified resin composites (compomers) in neutral and acidic buffer solutions. Two compomers (Dyract and Compoglass) were tested and the conventional glass-ionomer cement (GIC) Vivaglass Base served as a control. Forty specimens were fabricated from each of the respective materials. Twenty of these specimens were placed in artificial saliva and the other 20 specimens in a fluoridated dentifrice slurry for 5 min. Then, 10 fluoridated and 10 non-fluoridated specimens were immersed in a neutral buffer solution (pH 6.8), and the other specimens were immersed in an acidic solution (pH 4.0). After 1, 2, 3, 4, and 5 days the samples were again placed in either a fluoridated dentifrice slurry or saliva for 5 min, after which time they were transferred to fresh buffer solutions. The fluoride content of the solutions was assessed with a fluoride sensitive electrode. Fluoride release from all the materials decreased continuously during the experiment, with a significantly higher release in the acidic solution compared to the neutral buffer solution. Fluoridation did not result in an increased fluoride release for the compomers. However, the conventional GIC revealed a significantly higher fluoride release after fluoridation. It is concluded that Dyract and Compoglass can not be replenished with fluoride, irrespective of the pH value of the environment.
Attin
T
T
University of Freiburg, Department of Operative Dentistry and Periodontology, Germany. attin@zmk2.ukl.uni-freiburg.de
Buchalla
W
W
Siewert
C
C
Hellwig
E
E
D000704:Analysis of Variance; D002021:Buffers; D020770:Compomers; D003188:Composite Resins / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D017640:Silicates / Q000737:chemistry
D002021:Buffers; C105428:Compoglass; D020770:Compomers; D003188:Composite Resins; C088486:Dyract; D005899:Glass Ionomer Cements; D008689:Methacrylates; D017640:Silicates; C119198:Vivaglass Fil; D005459:Fluorides