Fouad S. Salama, BDS, MS, Cert. Pedo, DABPD, FAAPD,  Bassem F. ElMallakh, BSc, BDS, MSc, PhD
King Saud University College of Dentistry , Riyadh,KSA

 
Acidulated phosphate fluoride (APF) gels are commonly used as caries preventive materials in Pediatric Dentistry. APF gels are acidulated with phosphoric acid for the intended purpose of etching the enamel to enhance the fluoride uptake of teeth. Existing dental restorations, particularly glass ionomers and composite resins undergo etching and increased surface roughness when exposed to APF gels. Little work has been reported on the effect of topical APF application on the mechanical properties of restorative materials. Whether the surface microhardness of composites and glass ionomers are affected by such application is not known for sure. The aim of this study was to compare the surface microhardness of a compomer material (Dyract, De Trey Denstply), a composite resin (Prisma AP.H, LD Caulk), and a resin-modified glass ionomer (Fuji II LC, GC) following the application of 1.23% acidulated phosphate fluoride (APF) gel. Experimental specimens were treated with APF gel three times starting at 4Sh after mixing and with an interval of 48h in between (T_t, T₂, T₃). The surface microhardness of each material was determined after each APF gel application and compared to that of the same materia! without APF gel application as control. The results of this study showed that APF gel application did not affect the surface microhardness of the tested materials. It was also observed that the surface microhardness of Dyract and Fuji II LC were not significantly different from each other, both being significantly lower than Prisma AP.H.


Saudi Dental Journal 1996;8(2):81-86.