Part II: Crystalline Fluorapatite-Coated Hydroxyapatite Implant Material: A Dog Study With Histologic Comparison of Osteogenesis Seen With FA-Coated HA Grafting Material Versus HA Controls: Potential Bacteriostatic Effect of Fluoridated HA
Success of osteogenesis in bone graft procedures can be enhanced by inhibiting oral bacterial infections through the use of prophylactic bacteriostatic fluoride within the grafting environment. Ideally, the fluoride ion should be chemically sequestered and thus unavailable unless needed at times during the process of early infection. As fluoride within fluorapatite is tightly bound at neutral pH and becomes available only during acidic conditions, fluorapatite is an ideal store for the fluoride ion which becomes released for bacteriostasis only during an acidic environment found with incipient bacterial infection. The purpose of this investigation was to compare the histologic properties of new bone formed surrounding fluorapatite (FA)-coated microcrystalline hydroxyapatite (HA) grafting material with comparable bone formed following the use of control HA material (OsteoGen, Impladent, Ltd, Holliswood, NY). The results of histologic analysis within dog studies here showed no detectable difference in new bone following therapeutic grafting procedures using each of the above 2 mineral coatings.Abstract
Figure 1. The CT scan generated model of the dog jaw 4 months subsequent to tooth extraction. Figure 2. The prepared model for construction of custom cast titanium cages to house the hydroxyapatite (HA) or fluorapatite (FA) augmentation material. Figure 3. The finished custom cast titanium cage with retentive screw holes ready for HA coating. Note that the cast titanium cage is inlayed into the removed layer of stone from the model to simulate the exact position of the removed cortical plate of bone in the dog jaw. Figure 4. The retrieved dog jaw with the 2 cast titanium cages after 4 months in vivo.
Figure 5. Right fluorapatite side with bone growth inside and integration to the cage titanium mesh. No infection is noted. Figure 6. Left control hydroxyapatite (HA) side with bone growth inside and also integration to the cage mesh. One section of this cage was dehisced due to underlying infection. Figure 7. A montage of the integrated titanium cage mesh. It also shows microcrystals of HA totally engulfed in new viable bone.
Figure 8. A close-up of the hydroxyapatite (HA) surface integration of the titanium cage mesh. Also note the microcrystals of HA engulfed in viable new bone. Figure 9. A montage of the fluorapatite (FA) right-side titanium cage mesh. New bone is integrated to the HA-coated mesh. The nanocoating of FA on the microcrystals of HA is totally engulfed in new viable bone. Figure 10. A close-up of the FA-coated HA totally engulfed in new viable bone. No difference between the FA crystal reactions to bone morphogenesis compared to control HA.
Contributor Notes