THE TOPICAL APPLICATION EFFECT OF NANO-HYDROXYAPATITE VERSUS PLATELET RICH FIBRIN ON THE EARLY STAGES OF EXTRACTION SOCKET HEALING IN RABBITS: HISTOMORPHOMETRIC, HISTOCHEMICAL AND IMMUNOHISTOCHEMICAL STUDY

Introduction: The proper healing of extraction socket is essential for ridge preservation and better sequential prosthetic procedures. Several techniques and materials are developed for acceleration of socket healing. Two of the promising materials for this purpose are nanohydroxyapatite (NHA) and platelet rich fibrin (PRF); their mechanism of action and optimum application techniques are still not fully elucidated.
Purpose: To compare between NHA and PRF topical application in the enhancement of early stages of extraction socket healing in rabbits.
Materials & Methods: The mandibular first molars were extracted in twenty-four rabbits; the extraction sockets were divided into 3 groups: control group didn’t receive topical treatment. N and P groups received topical application of NHA and PRF respectively. Each group was subdivided into 2 subgroups according to the date of scarification after extraction: 1 week and 2 weeks. The extraction sockets were investigated by hematoxylin and eosin (H&E), Masson trichrome (MT) stains and proliferation cell nuclear antigen (PCNA) marker. The results were illustrated histologically and histomorphometrically.
Results: Both NHA and PRF treated groups in both 1 week and 2 weeks periods showed enhanced socket healing, more regular and mature bone in both H&E and MT stains as well as increased PCNA positive cells percentage in comparison to control group. The bone area in both periods and the osteocyte count after 1 week were highest in PRF group followed by NHA group while control group revealed the least values. These differences were statistically non-significant except the percentage of immuno-positive cells.
Conclusion: Both NHA and PRF improve the extraction socket healing process with slight preference of PRF particularly in the cellular proliferation in the first week after extraction.