Simvastatin granules allowed for osteogenesis around immediate implants, resulting in their osseointegration.

Objectives This study histologically compared the effect of TheraCal LC and biodentine on direct pulp capping using a rabbit model. Materials and methods A direct pulp capping procedure was performed on 40 mandibular central incisors of 20 healthy, male New Zealand white rabbits. TheraCal LC and biodentine were applied to exposed pulp and 10 randomly selected rabbits were euthanized after the first and second week. Incisors were extracted and prepared for histological processing and examination to check the dentine bridge thickness, continuity, and extent of pulp inflammation. A blinded data analysis was performed, and groups were compared using a Wilcoxon signed-rank test while changes across time within each group were assessed using the Mann–Whitney U test. Results When comparing the dentine bridge thickness, biodentine showed a significantly thicker dentine bridge in the first and second week (mean 28.16 µm, 33.66 µm), while TheraCal LC showed a dentine bridge in the second week only (mean 15.93 µm). Regarding dentine bridge continuity, biodentine showed a significantly better dentine bridge in the first week. Additionally, there was no difference in the second week. Furthermore, there was no statistically significant difference between each of the materials regarding the extent of inflammation. Conclusions Biodentine in vivo showed better results concerning thickness and continuity of the dentine bridge after direct pulp capping in rabbit incisors. Both biodentine and TheraCal LC had a similar inflammatory effect on the pulp. Clinical relevance Biodentine is more successful as a direct pulp capping material compared to TheraCal LC.

Background Glucocorticoids are used for the treatment of autoimmune disorders; however, they can elicit several side effects such as osteoporosis. Several approaches can be made to treat glucocorticoid-induced osteoporosis, including the use of stem cells. However, the therapeutic effect of mesenchymal stem cells depends on its released factors, including extracellular vesicles. Extracellular vesicles have been recognized as important mediators of intercellular communication as they participate in many physiological processes. The present study was designed to investigate the effect of bone marrow mesenchymal stem cells derived extracellular vesicles on the structure of alveolar bone in rats with glucocorticoid-induced osteoporosis. Methods Thirty adult albino male rats were divided into 3 groups: control group (CG), glucocorticoid-induced osteoporosis (GOG) and extracellular vesicles treated group (ExTG). Rats in the GOG and ExTG groups were injected with methylprednisolone acetate (40 mg/kg) intramuscularly in the quadriceps muscle 3 times per week for three weeks in the early morning. Afterwards, the rats in GOG group received a single vehicle injection (PBS) while each rat in the ExTG group received a single injection of extracellular vesicles (400 μg/kg suspended in 0.2 ml PBS) in the tail vein. Rats were euthanized 1 month after injection. Mandibles were dissected and the molar segments were prepared for histological preparation, scanning electron microscopy (SEM), and energy dispersive x-ray (EDX). Results Histology and scanning electron microscopyof bone tissue showed alveolar bone loss and bone resorption in the GOG group. while in the ExTG group, alveolar bone demostrated normal bone architecture. EDX showed that calcium percentage in GOG group was lower than ExTG group,which showed no statistically significant difference from the control group. Conclusions Extracellular vesicles may be a promising treatment modality in the treatment of bone diseases and in bone regeneration. However, further research is needed before stating that extracellular vesicles s can be used to treat bone disorders especially when translating to humans.

INTRODUCTION:Platelet rich fibrin (PRF) is an autologous healing biomaterial composed of a fibrin clot matrix entrapping leukocytes, cytokines, living progenitor cells, and platelets capable of releasing various growth factors harvested from a simple blood sample. OBJECTIVES: The aim of this experimental study was to evaluate the effect of PRF on angiogenesis during the periodontal regeneration of surgically created grade ΙΙ furcation defects in dogs. MATERIALS AND METHODS: A split mouth design was carried out using the third and fourth mandibular premolars of 2 healthy mongrel adult dogs. A total of eight grade II furcation defects were surgically created. The defects in the study side were augmented with PRF mixed with a β-TCP and covered by a PRF membrane and a collagen membrane. In the control side the defects were augmented with β-TCP and covered with a collagen membrane. The dogs were sacrificed after 1 and 2 months. Samples were dissected and prepared for histological evaluation. RESULTS: Histological results showed that PRF addition led to higher vascularization of the study samples at all age groups; this was evident at one month in the form of numerous blood vessels entrapping RBCs and at 2 months by the presence of red bone marrow and blood vessels entrapping RBCs within. CONCLUSIONS: The addition of PRF to β -TCP was found to be effective in enhancing angiogenesis during the periodontal regeneration of grade II furcation defects.

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