The efficacy of hydrothermally obtained carbonated hydroxyapatite in healing alveolar bone defects in rats with or without corticosteroid treatment

Abstract

Background/Aim. Autogenous bone grafting has been the gold standard in clinical cases when bone grafts are required for bone defects in dentistry. The study was undertaken to evaluate multilevel designed carbonated hydroxyapatite (CHA) obtained by hydrothermal method, as a bone substitute in healing bone defects with or without corticosteroid treatment in rats as assessed by histopathologic methods. Methods. Bone defects were created in the alveolar bone by teeth extraction in 12 rats. The animals were initially divided into two groups. The experimental group was pretreated with corticosteroids: methylprednisolone and dexamethasone, intramuscularly, while the control group was without therapy. Posterior teeth extraction had been performed after the corticosteroid therapy. The extraction defects were fulfilled with hydroxyapatite with bimodal particle sizes in the range of 50-250 μm and the sample from postextocactional defect of the alveolar bone was analyzed pathohystologically. Results. The histopatological investigations confirmed the biologic properties of the applied material. The evident growth of new bone in the alveolar ridge was clearly noticed in both groups of rats. Carbonated HA obtained by hydrothermal method promoted bone formation in the preformed defects, confirming its efficacy for usage in bone defects. Complete resorption of the material's particles took place after 25 weeks. Conclusion. Hydroxyapatite completely meets the clinical requirements for a bone substitute material. Due to its microstructure, complete resorption took place during the observation period of the study. Corticosteroid treatment did not significantly affect new bone formation in the region of postextractional defects.

Uvod/Cilj. Autogeni koštani graftovi predstavljaju zlatni standard u stomatologiji za popunjavanje koštanih defekata. Studija je sprovedena kako bi se ispitala efikasnost višefaznog karbonatnog hidroksiapatita (HA), dobijenog hidrotermalnam metodom, kao zamene za kost kod in vivo zarastanja koštanih defekata. Procena efikasnosti izvršena je patohistološkom analizom na pacovima (Sprague Dawley). Metode. Koštani defekti načinjeni su u alveolarnoj kosti ekstrakcijom bočnih zuba kod 12 pacova. Eksperimentalne životinje prvo su bile podeljene u dve grupe. Prva, kontrolna grupa, bila je bez terapije, dok je druga, eksperimentalna grupa intramuskularno dobijala kortikosteroidnu terapiju i to metilprednizolon i deksametazon. Ekstrakcija bočnih zuba izvršena je nakon resorpcije izazvane terapijom kortikosteroidima. Ekstrakcione rane ispunjene su hidroksiapatitom čestica veličine 50-250 μm, a uzorci uzeti iz postekstrakcionih defekata alveolarne kosti analizirane su patohistološki. Rezultati. Patohistološkom analizom potvrđena su biološka osteokonduktivna svojstva primenjenog materijala. Intenzivni rast nove kosti unutar alveolarnog grebena jasno je uočen u obe grupe eksperimentalnih životinja. Karbonatni HA dobijen hidrotermal nim metodom inicirao je formiranje kosti preko površine defekata, potvrđujući efikasnost njegove primene kod koštanih defekata. Do potpune resorpcije materijala došlo je posle 25 nedelja. Zaključak. Ispitivani hidroksiapatit u potpunosti zadovoljava kliničke zahteve kao zamena za kost, poštujući ograničenja eksperimentalne namene studije. Zbog mikrostrukture materijala došlo je do kompletne resorpcije tokom perioda posmatranja. Lečenje kortikosteroidima nije značajno uticalo na stvaranje nove kosti u predelu potekstrakcionih defekata. PR Projekat Ministarstva nauke Republike Srbije, br. 172026.