Objectives To produce a novel injectable treated dentin matrix hydrogel (TDMH) to be used as a novel pulp-capping agent for dentin regeneration compared with Biodentine and MTA. Materials and methods Thirty intact fully erupted premolars scheduled to be extracted for orthodontic reasons were included. Pulps were mechanically exposed in the middle of the cavity floor. TDMH was composed of TDM powder (500-μm particle size) and sodium alginate as an injectable scaffold. The capped teeth were divided into three equal groups (n = 10): TDMH, Biodentine, and MTA respectively. Clinical examination and assessment of periapical response were performed. The teeth were extracted after 2-weeks and 2-month intervals, stained with hematoxylin-eosin, and categorized by using a histologic scoring system. Statistical analysis was performed using chi-square and Kruskal-Wallis test (p = 0.05). Results All teeth were vital during observation periods. Histological analysis after 2 months showed complete dentin bridge formation and absence of inflammatory pulp response with no significant differences between groups. However, the formed dentin was significantly thicker with the TDMH group with layers of well-arranged odontoblasts that were found to form a homogenous tubular structure with numerous dentinal tubule lines showing a positive trend to dentin regeneration. Conclusions TDMH could achieve dentin regeneration and conservation of pulp vitality and might serve as a feasible natural substitute for silicate-based cements in restoring in vivo dentin defect in direct pulp-capping procedure. Trial registration PACTR201901866476410

INTRODUCTION: Bone is a unique tissue that undergoes frequent remodeling. An imbalance between bone formation and resorption results in osteoporosis. Glucocorticoids (GCs) are widely used clinically as anti-inflammatory and immunomodulatory. However, their prolonged use may induce osteoporosis. Currently, evidences revealed that also the alveolar processes are subject to osteoporosis. Bisphosphonates, such as Alendronate, Risedronate and Zoledronate, are recommended by several international guidelines as the first-line therapy for the prevention and treatment of generalized glucocorticoids induced osteoporosis (GIOP). OBJECTIVES: To evaluate the effect of bisphosphonates (Risedronate) on the alveolar bone of rats with glucocorticoids induced osteoporosis. MATERIALS AND METHODS: Thirty female albino rats were divided into 3 equal groups (10 rats each) as follows: Group I: control group. Group II: glucocorticoids group (Dexamethasone 0.6mg/kg twice/week subcutaneously). Group III: Risedronate treated group; rats were given Dexamethasone (0.6mg/kg twice/week subcutaneously) and Risedronate (1mg/kg/day orally). After 12 weeks, rats were euthanized, and the mandibular alveolar bone was evaluated histologically by light microscope and ultra-structurally by scanning electron microscopy and energy dispersive X-ray (EDX) microanalysis. RESULTS: Group II showed deterioration of the alveolar bone in comparison to the control group I. The alveolar bone structure in Group III rats, treated by bisphosphonates (Risedronate), showed remarkable improvement both histologically and ultrastructurally in comparison to group II. Moreover, EDX analysis revealed a significant decrease of calcium levels in group II in comparison to group I. However, in group III calcium levels were restored to normal levels comparable to the control group I. CONCLUSIONS: Glucocorticoids intake induces loss of the alveolar bone; which, could be counterbalanced by bisphosphonates.

INTRODUCTION: Tooth extraction socket healing is a complex process, which involves tissue repair and regeneration. Concurrent with bone growth into the socket, there is also well-documented resorption of the alveolar ridges. Therefore, the socket preservation concept was introduced. One of the top ranked evidence-based herbal medicines, which has been described as the "miracle herb of the century" is Nigella sativa (NS). N. sativa has been extensively studied for its biological activities and therapeutic potential and shown to possess wide spectrum of activities. OBJECTIVES: To evaluate the biological effect of Nigella sativa on socket healing in rabbits. MATERIALS AND METHODS: Twelve healthy rabbits were used in this study, lower first premolars (right and left) were extracted. All right sockets were left for normal healing as a control group, while the left sockets are considered as the study group and they were treated with Nigella Sativa. All sockets were sutured. Rabbits were sacrificed after two weeks. Their mandibles were dissected out to be processed for histological examination under the light microscope. RESULTS: In the control group, the histological examination of the socket revealed randomly arranged thin bony spicules lined by flattened layer of osteoblast cells on its surface, enclosing fibrous bone marrow with limited vascularity. Osteocytes were of moderate size and density. In the Nigella sativa treated group sockets exhibited more active bone formation, thick trabeculae with highly vascular bone marrow and large numerous osteocytes. Certain areas show replacement of woven bone with mature bone where bone remodeling takes place. CONCLUSIONS: Use of Nigella sativa after extraction in the healing sockets could enhance bone formation and accelerate the process of socket healing

Papacarie produced a rough and porous surface with partial or complete removal of the smear layer and opened dentinal tubules, while the drill produced a smooth surface with uniform smear layer occluding the dentinal tubules.

INTRODUCTION: The use of biodegradable screws has a number of limiting factors including poor mechanical stability, difficult handling properties, and time-consuming fixation. A new application system by welding a special configured resorbable pin through ultrasound may overcome the disadvantages of thread tapping. OBJECTIVES: Was to evaluate resorbable plates with ultrasonic welded pins in management of midface fracture. MATERIALS AND METHODS: Was conducted clinically on 20 midface fracture cases fixed with resorbable plates with ultrasonic welded pins, histologically on 4 healthy adult mongrel dogs, and biomechanically on 15 specimens tested for tension, bending, and torsion stiffness of this system. RESULTS: Clinically intraoperative handling showed 13% failure rate for the total number of pins placed for all cases, with stability failure in 10% of cases, and mean time needed for fixation of each plate was 10.6 minutes, however postoperative clinical results were normal with no significant complications. Radiographically; adequate bone healing with delayed resorption of pins was observed during follow-up phase which was continued till 12 th week postoperatively. Histological study revealed woven bone growing in the defect area and development of new bone, osteocytes and osteoblasts seen on bone surface. Biomechanical study showed mean tensile stiffness 498.982 N/mm while mean bending stiffness was 1.176 N/mm and mean torsion stiffness was 0.342 N/mm. CONCLUSIONS: This retrospective study shows the general feasibility, sufficient mechanical stability, and efficient intraoperative handling of resorbable plates with ultrasonic welded pins in management of midface fractures.