Estudo in vivo da hidroxiapatita no cimento endodôntico e seu efeito osteocondutor em ratos Wistar (Rattus norvegicus).

Abstract

This paper was evaluated the effect of adding 1, 3 and 5% by weight of hydroxyapatite (HAp) on MTA sealer cements endododontics aiming to acquire new osteoconductive property. To this end, in vivo studies of bone defects in rat femurs of Wistar type was investigated. The sealers were cooked with percentages of 1, 3 and 5 wt% of HAp synthesized in our laboratory using the method of precipitation and subsequently heat treated at 1300ºC added to commercial MTA. The MTA, the HAp and the cements were characterized by X-ray diffraction (XRD) spectroscopy, infrared Fourier transform (FTIR), X-ray fluorescence (EDX), scanning electron microscopy (SEM) , radiographic appearance, consistency, setting time and in vivo assays. The results show that MTA had commercial composition and consistency characteristics of a hydraulic cement, with absorption bands corresponding to groups phosphate, silicate, carbonate, and Bi-O, OH-, morphology consisting aglomeradoscom high radiopacity due to bismuth oxide present in its composition and hardening time of 20 minutes. A HAp produced experimentally resulted in a product phase, with absorption bands corresponding to OH- group and the phosphate and carbonate, consisting of fine particles in form of agglomerates, low radiopacity, hardening time of 10 minutes. The new sealers resulted in products produced with the same crystalline phases, absorption bands and the chemical composition of their precursor materials, but with time and radiopacity hardening near the MTA pure. Through in vivo assays (analyzes radiographic, histologic and statistics), it was found that the concentration of 5% hydroxyapatite provided the best osteoconductive properties to the MTA. Thus for use in public health through conservative dental treatment as direct and indirect pulp capping, pulpotomy and periradicular surgical procedures, indicates the hydroxyapatite as the best material for the induction of dentinal bridges. Already considering the case of sealing infiltration in endodontic treatments, the MTA/HAp5% is the best material for this present MTA sealing function, along with the induction of new bone formation of HAp, reducing the time of follow up.