COMPARATIVE EVALUATION OF OSTEOTROPIC ACTION OF ENDODONTIC FILLING MATERIALS ON THE MODEL OF EXPERIMENTAL DESTRUCTION OF BONE TISSUE OF THE JAW OF RATS

• Main Author: I. Han
• Format: Article
• Language: English
• Published: Ukrainian Medical Stomatological Academy 2016-03-01
• Series: Український стоматологічний альманах
• Subjects: biomaterials, regeneration, experiment, alkaline and acid phosphatase, calcium, phosphorus.
• Online Access: https://dental-almanac.org/index.php/journal/article/view/129
• ISSN: 2409-0255; 2410-1427

The purpose of our research was to determine the dynamics of reparative processes in the bone tissue under the influence of drugs and compositions. The experiment was conducted on 120 white rats Wistar line, aged 9-10 weeks, herd breeded. To create a bone defect intervention was performed under general anesthesia (0.5 ml 4% solution of sodium thiopental into the peritoneum). On the left side of the lower jaw of the animals in the area between the incisor and right molar was created bone defect which was filled with studied biomaterials or was left with grume. All animals were divided into 6 research groups and 20 individuals in each: first group intact animals that were served as a control; second comparative group - animals on which bone defect was created without entering the biomaterial; the third group - animals on which material Nano Gen to fill the defect was used; fourth group - animals, on which mineral trioxide aggregate (MTA) in the created defect was entered; fifth group – animals, which defect was filled with the composition based on beta-tricalcium phosphate (β-TCP); sixth group – animals, which created defect in a bone was entered with the composition made from calcium hydroxyapatite (HA). From the experiment the rats were taken out after 15 and 90 days. For biochemical studies dissection of the lower jaw alveolar sprout defect area was used. In homogenates of bone fabric the activity of lysosomal enzymes - alkaline (ALP) and acid (CF) phosphatase, calcium (Ca) and phosphorus (P) was examined. Results.In 14 days in the second group of animals KF content increased in 1.5 times compared to the data in intact bone (Table 1). Similar results were obtained in the third and fourth experimental groups (p <0.001). In V and VI groups of animals was observed growth of KF content only in 1.2 and 1.3 times, in accordance (p <0.001). CF is a biomarker of bone tissue, which characterizes the activity of osteoclasts and intensity of osteolysis. Therefore, its high concentration in II, III and IV groups of animals indicates higher activity of osteoclasts and shows sharper course of inflammation compared to animals of V and VI groups. Simultaneously, changes of the content and the other biomarker of bone fabric – ALP were observed. In the second group of animals the enzyme activity increased in 1.25 times (p <0.001), and in the III and IV groups of animals - in 1.3 times (p <0.001) compared to the control group of animals. In the V and VI of research groups – in 1.9 times (p <0.001) compared to intact bone. LF is a marker of osteoblasts’ activity and characterizes intensity of osteogenesis. Activity of processes of osteogenesis and osteolysis during bone regeneration characterizes the index of mineralization, which is defined by LF / CF. (). In the II, III and IV groups of animals index decreased by 18%, 16% and 14% in accordance compared to intact animals, demonstrating the predominance of processes of osteolysis over osteogenesis. In the V and VI groups of animals was observed the increase of the index by 44% and 47% in accordance, indicating a prevalence of regenerative processes of osteogenesis. For 90 day after modeling of degradation activity of LF and CF in the bone tissue was decreasing and approaching to the values of their activity in the group of intact animals, indicating the restoration of balance of processes of osteogenesis and osteolysis. However, analysis of the results shows that in the V and VI experimental groups content of KF is the lowest and almost closed to the value of intact animals (p> 0.05), while LF content remains the highest among all the indicators of research groups (p <0.001), indicating a decrease of the function of osteoclasts and stimulation of the activity of osteoblasts and proves that the proposed compositions stimulate osteogenesis the most actively. The content of calcium ions on the 14 day of study in the ІІ and ІІІ groups of animals (table 2) decreased in 1,8 times, and in the IV group – in 1,6 times in the V experimental group – 1,5 times and in the VI - in 1,3 times relatively the indicators of control group and is essential in all experimental groups (p <0.001). A content of ions of phosphorus in the II, III and IV groups of animals is reduced in 1,8; 1,7 and 1,5 times accordingly in the experimental group V - 1.4 times and VI in the experimental group - 1.3 times relatively to the indicators of the control group (p <0.001). Reducing of index of correlation of calcium and phosphorus points on the calcium deficiency compared to phosphorus. For the 90 day of the study content of calcium ions in the ІІ, ІІІ groups is reduced in 1,6 times, in the IV group – in 1,3 times, and in the V and VI experimental groups in 1,1 and 1,01 times in accordance relatively to the indicators of control group (p <0.001). The content of phosphorus ions in the ІІ , ІІІ groups of animals has decreased in 1,5 times, in the IV group – in 1,3 times, and in the V and VI of experimental groups - in 1.1 times relatively to the indicators of the control group (p <0.001). Reducing of index of correlation of calcium and phosphorus on the 90 day compared to the 14 day indicates a deceleration of calcification processes. Osteotropic compositions based on beta tricalcium phosphate and calcium hydroxyapatite stimulate more processes of osteogenesis than drugs MTA and Nano Gen, affecting on mineralized function that shows the increasing of te content of ALP, reducing the concentration of CF and, in addition, increasing their indicator of mineralization. Approaching to the normal indicator of correlation of calcium and phosphorus points on the positive impact of the proposed compositions on calcification processes. The article presents a comparative assessment of the dynamics of the reparative process of the bone tissue under the influence of drugs MTA and Nano Gen and compositions based on the beta-tricalcium phosphate and calcium hydroxyapatite, containing organic biorevitalizants. The experiment was conducted on 120 white rats, on which a bone defect was made and was filled with investigative biomaterials. From the experience animals were taken for 15 and 90 days by decapitation under anesthesia and in homogenates of bone tissue which were investigated of the activity of lysosomal enzymes - alkaline and acid phosphatase, content of calcium and phosphorus. Higher concentrations of alkaline phosphatase, below the acid phosphatase and the approximation to the normal correlation of calcium and phosphorus in the homogenate bone, defect of which was filled with compositions based on hydroxyapatite calcium and beta-tricalcium phosphate, compared to the groups of animals in the area of degradation that have been bringing in MTA and Nano Gen indicates at more active stimulating of osteogenesis and calcification of bone tissue.