The impact of synthetic bone grafting for tissue regeneration: an in vivo study

Aims: This study aimed to examine the biological response of synthetic nanocomposite material on canine mandibular bone. Methods: Nine healthy adult male local breed dogs aged 12 to 18 months and weighing 10.2 to 15.2 kg were used in the study. Based on healing intervals of 1 and 2 months, the dogs were divided into 2 groups. Each group had 3 subgroups with 3 dogs each. The division was based on the grafting material used to fill the created defect: an empty defect (Control-ve), Beta-Tricalcium Phosphate, and nanocomposite (Beta-Tricalcium Phosphate and nanosilver 1%) . Surgery started after the dogs were anaesthetized. The surgical procedure began with a 5 cm parallel incision along the mandible's lower posterior border. After exposing the periosteum, a three 5mm-diameter, 5-mmdeep critical-size holes were made, 5mm between each one. Each group's grafting material had independent 3 holes. The defects were covered with resorbable collagen membranes followed by suturing of the mucoperiosteal flap. Results: Total densitometric analysis showed no significant differences between groups at 1-month intervals, with the nanocomposite group having a higher mean rank (165.66± 31.21) in comparison to other groups while at 2 months intervals that there was a highly significant difference between three groups as the P-value was (0.000) with the nanocomposite group having a higher mean rank (460.66± 26.40). Conclusions: In the current study, the use of nanocomposites improved osteoconductivity by accelerating new bone formation. Moreover, the encorporation of nanosilver enhanced growth factor activity. These attributes make nanocomposites a promising material for enhancing the bone healing process

Clinical and histological evaluation of the effect of magnesium oxide administration on relapse after orthodontic teeth movement (Rabbit Model Study).

OBJECTIVE: This study aimed to evaluate the clinical and histological administration of magnesium oxide (MgO) supplementation on orthodontic relapse and bone remodeling. MATERIALS AND METHODS: Twenty male albino rabbits were classified into four groups (five animals for each as two control (positive and negative), plus two experimental (low dose 40 mg/kg) and (high dose 80 mg/kg)/b.w. daily). An orthodontic force was applied (40 gm) to the lower incisors using modified orthodontic appliance adapted on the lower central incisors. During the period of retention, MgO was given orally. Relapse was estimated after appliance removal. A digital Calliper was used to compete the space between incisors' mesial tips of rabbits at six successive time points (0, 3, 7, 10, 15, and 21 days). Histologically, osteoblast, osteoclast, and osteocyte account were assessed. Data analyses were performed by SPSS using ANOVA and Tukay HSD (P ≤ 0.05) for statistically significant differences between groups. RESULTS: The high dose group had a lower relapse rate than the low dose and control groups. Histologically, the high dose group had more osteoblasts and osteocytes than low dose and control groups. While osteoclasts were significantly lower than the control group in low and high dose groups. CONCLUSIONS: MgO supplementation during an orthodontic retention phase, particularly at a level of high dose, clinically decreased orthodontic relapse in a rabbit model. Histologically, MgO has a significant effect on alveolar bone after the orthodontic retention period.

Does systemic anticancer gemcitabine compromise oral soft tissue wound healing? / ¿La gemcitabina anticancerígena sistémica compromete la cicatrización de heridas en tejidos blandos orales?

Background: Numerous types of cancer are of substantial medical and social concern, posing a major challenge to modern medicine. Chemotherapeutic drugs include the use of nucleosides, which are composed of nucleic acid and sugar. Objective: This study aims to assess the impact of systemic chemotherapeutic drugs at a therapeutic dose on the wound healing process of the oral mucosa. Material and Methods: 30 healthy rats were randomly divided into two main groups based on the study material, 15 rats in each group. Group A (control) was given a single dose of normal saline (1ml/kg, intraperitoneal), and Group B (study) a single injection of gemcitabine (50 mg /Kg, intraperitoneal). After anesthesia, a full-thickness soft tissue incision (0.5 cm length) on the right side of the buccal mucosa was made in the animals of both groups. Each group was subdivided according to the time of sacrifice into 3, 7, 14 days after surgery, at the end of the experimental periods, specimens were collected for histopathological study, and samples of blood were obtained from retro-orbital venous plexus and collected in microfuge tubes and levels of antioxidant enzymes were measured by ELISA. The data were analyzed statistically at a 0.05 level of significance. Results: Gemcitabine delayed the onset of wound cascade (inflammation and re-epithelization) which lead to worsening healing of the oral tissue; it also resulted in a decrease of the antioxidant activity of glutathione peroxidase and catalase, as well as activated caspase 3, which induces cell apoptosis. Conclusion: Gemcitabine showed negative feedback on oral tissue wound healing through delayed wound healing cascade and by inducing apoptosis.

Antecedentes: numerosos tipos de cáncer son motivo de gran preocupación médica y social, lo que representa un gran desafío para la medicina moderna. Los fármacos quimioterapéuticos incluyen el uso de nucleósidos, que están compuestos de ácido nucleico y azúcar. Objetivo: Este estudio tiene como objetivo evaluar el impacto de los fármacos quimioterapéuticos sistémicos a una dosis terapéutica en el proceso de cicatrización de heridas de la mucosa oral. Material y Métodos: 30 ratas sanas se dividieron aleatoriamente en dos grupos principales según el material de estudio, 15 ratas en cada grupo. Al grupo A (control) se le administró una dosis única de solución salina normal (1 ml/kg, intraperitoneal) y al grupo B (estudio) una inyección única de gemcitabina (50 mg/kg, intraperitoneal). Después de la anestesia, se realizó una incisión de tejido blando de espesor total (0,5 cm de longitud) en el lado derecho de la mucosa bucal en los animales de ambos grupos. Cada grupo se subdividió de acuerdo al tiempo de sacrificio en 3, 7, 14 días después de la cirugía, al final de los períodos experimentales se colectaron especímenes para estudio histopatológico, se obtuvieron muestras de sangre del plexo venoso retroorbitario y se recolectaron en tubos de microcentrífuga y los niveles de enzimas antioxidantes se midieron por ELISA. Los datos se analizaron estadísticamente a un nivel de significación de 0,05. Resultados: La gemcitabina retrasó el inicio de la cascada de heridas (inflamación y reepitelización) que condujo a un empeoramiento de la cicatrización del tejido oral; también resultó en una disminución de la actividad antioxidante de la glutatión peroxidasa y la catalasa, así como de la caspasa 3 activada, que induce la apoptosis celular. Conclusión: La gemcitabina mostró retroalimentación negativa sobre la cicatrización de heridas del tejido oral a través de una cascada de cicatrización retardada y mediante la inducción de apoptosis.