Enhancement of Fracture Toughness in carbonate doped Hydroxyapatite based nanocomposites: Rietveld analysis and Mechanical behaviour.

Highly nanocrystalline carbonated hydroxyapatite (CHAp) is synthesized by hydrothermal technique with four different stoichiometric compositions for microstructural and mechanical analysis. HAp is one of the most biocompatible material and addition of carbonate ions lead to increase in fracture toughness highly required in biomedical applications. The structural properties and its purity as single phase is confirmed by X-ray diffraction. Lattice imperfections and structural defects is investigated using XRD pattern model simulation, i.e. Rietveld's analysis. The substitution of CO32- in HAp structure leads to a decrease in crystallinity which ultimately lessens crystallite size of sample as verified by XRD analysis. FE-SEM micrographs confirms the formation of nanorods with cuboidal morphology and porous structure of HAp and CHAp samples. The particle size distribution histogram validates the constant decrease in size due to carbonate addition. The mechanical testing of prepared samples revealed the increase in mechanical strength from 6.12 MPa to 11.52 MPa due to the addition of carbonate content, which leads to a rise in fracture toughness, a significant property of an implant material from 2.93 kN to 4.22 kN. The cumulative effect of CO32- substitution on HAp structure and mechanical properties has been generalized for the application as biomedical implant material or biomedical smart materials.

Dentigerous cyst associated with mandibular 2nd molar: an unusual entity.

Dentigerous cysts are generally associated with the crowns of impacted or unerupted permanent teeth and are more common in males, in the second and third decades of life. Most dentigerous cysts are mainly developmental in origin but may not be similar for all cases. The purpose of this paper is to present a case of dentigerous cyst with unusual presentation in a 7 year old girl and discuss the variation in etiology, presentation of such a cyst and in its management.

Calcifying epithelial odontogenic tumor in anterior maxilla associated with a supernumerary tooth: a case report.

Odontogenic tumors are derived from epithelial, ectomesenchymal and/or mesenchymal elements that are or have been a part of the tooth-forming apparatus. Of all the odontogenic tumors, calcifying epithelial odontogenic tumor accounts for 1% of the cases. Approximately 200 cases have been reported to date. There is no sex predilection, with a 2:1 predilection for the mandible, mostly in the premolar/molar region. It is often locally invasive. Most often, it is associated with an impacted tooth, is asymptomatic and requires biopsy for diagnosis. Presented here is a rare case of an intraosseous calcifying epithelial odontogenic tumor surrounding a supernumerary tooth. Furthermore, the occurrence of this tumor in the anterior maxilla (an uncommon site) in a pediatric patient makes it rarer. Although the present case was asymptomatic, root resorption and displacement of adjacent teeth necessitated its surgical removal. The lesion was surgically enucleated and histopathological examination confirmed calcifying epithelial odontogenic tumor, showing abundant calcifications in the form of Liesegang rings.

Evaluation of different treatment modalities for closure of oro-antral communications and formulation of a rational approach.

Oro-antral communication is a common occurrence following removal of maxillary premolars and molars because of anatomic proximity of root apices of these teeth and maxillary antrum. Various methods have been described in literature for closure of these communications which vary from simple local methods like buccal advancement flap to complex distal flaps and grafts. Out of these plethora of the treatment modalities available for the treatment of oro antral fistula, the most simple and commonly used ones are either the buccal flap or the buccal pad of fat. In our study we compared the results, advantages and disadvantages of using buccal advancement technique and buccal fat pad individually and also in combination. With this paper, we aim to shed light on the efficacy of buccal pad of fat and the buccal flap, either alone or together, for the closure of OAF of various regions. We also aim to provide a systematic and rational approach for repair of oro-antral communications.