2004 Volume 3 Issue 1 Pages 69-77
Purpose : The purpose of this study was to histologically examine the hydroxyapatite (HA)-coated layer of endodontic endosseous implants after clinical application. The HA was applied using a high-velocity flame-spraying technique (HVFST).
Materials and Methods : Two implants placed six years earlier in two different patients were studied. The first patient was a 24-year-old man who received implant therapy to improve the crown : root ratio after removal of a radicular cyst. The second patient was a 15-year-old boy in whom an implant was placed to restore the dentition after dental root breakage. The extracted materials were fixed in a 10% formalin solution and examined with light microscopy and scanning electron microscopy (SEM).
Results : Because the implants adhered tightly to the bone, it was necessary to remove both the implant and the surrounding bone. Histological examination using toluidine blue staining in an SEM indicated some remaining HA coating that directly contacted the bone in the first patient. In the second patient, SEM showed that the HA coating had been resorbed, and the bone had bound directly to the titanium.
Conclusion : Although each of the implants had been in use for six years, the coated HA layers displayed completely different phenomena. We concluded that the causes for this difference were related to the limitations of the HA coating technique and various long-term clinical conditions.
