Objectives: The aim of this study was to investigate the mechanical properties as well as the structural analysis of autologous platelet-rich fibrin matrix (PRFM) as compared to autologous leukocyte-platelet-rich fibrin (L-PRF).Materials& Methods: Sixty three cubic centimeters (cc) venous blood was obtained from 10 male volunteers. Twenty seven cc were used to prepare 3 specimens of L-PRF (group 1), twenty seven cc were used to get 3 specimens of PRFM (group 2) and nine cc for whole blood analysis. After centrifugation, blood analyses were performed on the residual plasma after collecting L-PRF and PRFM. The L-PRF and PRFM membranes were processed for examination by light microscopy and transmission electron microscopy (TEM) and their mechanical properties were measured by a universal testing machine.Results:Tensile strength and maximum tensile strain of L-PRF group was significantly higher than PRFM group (p < 0.01). PRFM group was significantly stiffer than L-PRF group (p < 0.01). Light microscopy revealed that the platelets were less but more equally distributed in the PRFM than L-PRF. The border between the cellular components and the fibrin network appeared thicker in the PRFM samples than in the L-PRF samples and shows a highly organized network with continuous integrity. TEM showed that both membranes contained two components: a fibrillar material similar to fibrin filaments, and a cellular component that contains human platelet cells. TEM analysis demonstrated that PRFM membrane had more nonactivated platelets.Conclusion: The present study shows that the structural and mechanical properties of PRFM may fit characteristics desirable for GTR procedures more than that of L-PRF. KEYWORDS:Mechanical properties, platelet-rich fibrin matrix, leukocyte-platelet-rich fibrin (1532) Reham Lotfy Aggour, et al.

Introduction: The mammalian tongue displays significant morphological differences. These differences seemed to be related to the nature of food. Also, the surrounding environmental conditions play an important role in these differences. The dorsal mucosa of the tongue is covered by numerous papillae. In many mammals, tongue papillae play a vital role in food intake and digestion. The aim study: This study was to investigate the morphological characteristics of the circumvallate papillae (CVPs) of rat, dog, rabbit and goat. Materials and Methods: For this purpose, tongues of these animals were examined macroscopically as well as with light and scanning electron microscope (SEM). Results: Grossly observations reveled, in ratsa single large CVP surrounded by a semicircular moat and an indistinct annular pad. In dogs, five CVPs were arranged in two lines. The large papillae were surrounded by a wide moat and a prominent annular pad. Whereas, the small papilla lacked the annular pad and had irregular ridges.In rabbits, two CVPs enclosed by a deep moat lacking the annular pad. Whereas, goats had eight pairs of CVPs on both rims of the torus linguae and were encircled by a prominent gustatory moat and a thick annular pad. Histological examination of the four species revealed taste buds were located in the medial and lateral walls of the moat except for goats that had taste buds only in the medial wall of the moat. SEM examinationof the papillary surface exposedtransverse grooves in rats, irregular microridges and grooves in dogs and rabbits whereas the goats showed very little and small grooves. Conclusion: Hence, this study highlighted a variation in the morphology and microscopic anatomy of CVPsas an adaptation to their different feeding behaviours.

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This study aimed to assess the histological changes in the maxillary sinus and its adjacent dental tissues as pulp and periodontal ligament during pregnancy and investigate the role of estrogen hormone in these changes through the detection of estrogen receptors in these tissues. Sixteen adult female rats were used and were allocated into two groups: control non-pregnant (n = 8) and pregnant (n = 8). They were sacrificed and their heads were prepared for histological and immunohistochemical examination for estrogen receptor alpha. Our results revealed that pregnant rats revealed inflammatory changes in the sinus as thick epithelial lining, loss of cilia, swollen goblet cells, intraepithelial and interstitial edema. The lamina propria demonstrated considerable infiltration of inflammatory cells, glandular hyperplasia with vacuolar degeneration, and vascular congestion. Periodontal ligament and pulp revealed hyperemia and vascular congestion. Immunohistochemical examination of estrogen receptor alpha in the maxillary sinus and adjacent dental tissues (Periodontal ligament and pulp) in pregnant rats revealed a significant increase in its expression in all examined tissues. In conclusion, there was an increase in expression of ERα in the sinus mucosa and dental tissues during pregnancy together with slight inflammatory changes in these tissues. Hence, dentists should be aware of the effect of these changes on the pregnant women avoiding teeth extraction due to misdiagnosis of dental, periodontal or sinus pain after exclusion of true pathologies.

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Background: Methylprednisolone causes a delay in dental extraction wound healing. There are finite data for the effect of Aloe Vera gel and silver nanoparticles gel on tooth socket healing in methylprednisolone treated Albino rats. Purpose: To evaluate the topical effect of using Aloe Vera gel versus silver nanoparticles gel on socket healing in methylprednisolone treated Albino rats. Materials and Methods: Adult male Albino rats were divided into three groups. Group I (control group); Subgroup A and Subgroup B: received intramuscular injection of sterile normal saline and methylprednisolone acetate (0.2 mg/kg, 3 times/ week for 5 weeks) respectively. After this period, lower right first molars were extracted. Group II and Group III were as group IB while, the sockets were filled with 92% Aloe Vera and silver nanoparticles gel respectively. Rats were sacrificed at day 7 and day 14. Rats' sockets were processed for histological and scanning electron microscopic examination. Results: Group IB showed a delay in socket healing. Group II showed the socket was filled with osteoid matrix at day 7. Then the socket was nearly filled with thick intercommunicating lamellar bone trabeculae with wide bone marrow spaces at day 14. Surprisingly, Group III revealed thin intercommunicating woven bone spicules at day 7. At day 14, the socket became nearly obliterated with thick intercommunicating bone trabeculae with formation of numerous primary osteons with small bone marrow spaces. Conclusion: MP had a marked osteoporotic effect on rat mandible and delayed the socket healing process. Aloe Vera gel and AgNps gel improved the socket healing in MP treated Albino rats.

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