Objectives: The healing of bone defects in the craniofacial region is an important clinical issue. We aimed to compare the effects of OCTACALCIUM PHOSPHATE (OCP) and the combination of OCP/gelatin (OCP/Gel) on calvarial bone regeneration in rats. Materials and Methods: In this study, 72 male Sprague Dawley rats were randomly assigned to the OCP (n=24), OCP/Gel (n=24), and control groups (n=24). Lesions with a diameter of 9 mm were created in the parietal bone and were filled with 9-mg OCP and OCP/Gel disks. In the control group, no substance was implanted in the defect. Sampling was performed on days 10, 14, 21, and 28 after the implantation. After tissue processing, 5-μ m sections were prepared and stained by hematoxylin and eosin (H&E) stain. The sections were studied, and the volume fraction of the newly formed bone was assessed by Kruskal-Wallis test at a significance level of 0. 05. Results: In the experimental groups, new bone formation was detected at the margins of the defects 10 days after the implantation. With the progression of the healing process, the newly formed bone covered greater areas of the defects and developed a more mature structure. In the control group, the defects were primarily filled with a dense connective tissue with small islands of new bone. The results of histomorphometric assessments showed that the volume of the newly formed bone in the experimental groups had a significant statistical difference with that in the control group (P<0. 001). Conclusions: The OCP/Gel composite can be useful in the healing process of calvarial bone defects.

Background and Aim: Reconstruction of craniofacial bone defects remains one of the most challenging problems encountered by maxillofacial surgeons. This study was designed to investigate the process of bone formation caused by implantation of OCTACALCIUM PHOSPHATE at mandibular alveolar ridge of rat.Methods & Materials: In this experimental animal study, 20 male Sprague Dawley rats were used. Synthetic OCTACALCIUM PHOSPHATE (OCP) was implanted into the bony defect measuring 3 mm in diameter and 2 mm in depth which was surgically created with a bur in the rat mandible. Bone formation at the alveolar ridge was examined histologically between I and 4 weeks after implantation.Result: Osteogenesis was initiated in the center of the defect between the OCP particles and multinucleated giant cells appeared on the implanted materials in 1 week. More apposition of new bone was observed on the implanted OCTACALCIUM PHOSPHATE in week 2. In addition to bone formation locally around the OCP particles, more apposition of new bone was observed near the defect margin in week 3. At week 4, the defect was almost completely filled with bone, which was in close contact with host bone and implanted OCP was surrounded by newly formed bone. In the control group, bone formation was observed only along and near the defect margin.Conclusion: OCTACALCIUM PHOSPHATE could be used to enhance atrophic alveolar ridge or for filling a tooth socket after extraction.

Biphasic calcium PHOSPHATEs (BCPs) of hydroxyapatite/OCTACALCIUM PHOSPHATE (HA/OCP) with mixed morphology of whisker/spherulite were synthesized and characterized by the precipitationhydrolysis method in an acidic solution containing calcium and PHOSPHATE ions and carbonyl diamide. The synthesized solutions were refluxed at 90 °C for 3 or 4 days. The crystalline structure of products was determined by X−ray diffraction (XRD). Fourier transformed infra-red spectroscopy (FTIR) was used to characterize the absorption spectrum. The morphology of products was evaluated by scanning electron microscopy (SEM). The results showed the presence of carbonyl diamide (CA) in synthesized solutions with a Ca/P molar ratio of 1.67 led spherulites to be formed and then whiskers such that an increase of CA concentration was associated with an increase in whisker length and a decrease in spherulite diameter. The concentration of CA was more effective than calcium concentration and Ca/P molar ratio on the size of whiskers. The increase of reaction time may give rise to change the morphology of whiskers to lath-like one (increasing the whisker width) and spherulites from flowerlike forms to microspheres. The appropriate chitosan-based composite scaffolds containing various amounts of calcium PHOSPHATE phase with a homogenous microstructure of 65−80 porosity are percent and pore size of 50-400 μm could be produced for hard tissue engineering applications. The porosity of scaffolds was decreased with increasing the calcium PHOSPHATE phase.

In order to evaluate bone induction and repair in cranial bone defects by the use of OCTACALCIUM PHOSPHATE (OCP), the authors used 40 young male Sprague Dawley rats (5-6 weeks age) The OCP was which they made use of it in the present study was prepared by a method, namely legeraus method. A defect with 5mm diameter was produced in parietal bones and then 5mg OCP was implanted in the place of the defect. On the 5th 7th 14th and st days after the operation, the specimens were taken out of the defect.After processing the tissues by routine procedures, the authors prepared 5 micron sections of the samples, stained them with H&E and finally studied the sections by light microscope. On the 5th day, they noticed inflammatory cells around the implanted OCP. On the 7th day after the operation, osteogenesis was initiated from the margin of the defect. And finally on the 14th day and the days after, in addition to bone formation from the margins towards the centre, they observed more oppositions of new bones locally around the OCP particles. At the end of 21st day, almost all of the OCP particles were absorbed and bone trabeculae, marrow cavities, bone marrow tissues were appeared. As the findings show OCP could stimulate bone induction and new bone formation in bone defects, so it seems that OCP could be used in the repair of cranial bone defects.

Background: Regeneration of bone defects remains a challenge for maxillofacial surgeons. The objective of this study was to assess the osteogenic potential of OCTACALCIUM PHOSPHATE (OCP) and bone matrix gelatin (BMG) alone and in combination with together in artificially created mandibular bone defects. Materials and Methods: In this experimental study Forty‑ eight male Sprague– Dawley rats (6– 8 weeks old) were randomly divided into four groups. Defects were created in the mandible of rats and filled with 10 mg of OCP, BMG, or a combination of both (1/4 ratio). Defects were left unfilled in the control group. To assess bone regeneration and determine the amount of the newly formed bone, specimens were harvested at 7, 14, 21, and 56 days postimplantation. The specimens were processed routinely and studied histologically and histomorphometrically using the light microscope and eyepiece graticule. The amount of newly formed bone was quantitatively measured using histomorphometric methods. Histomorphometric data were analyzed using SPSS software. Mean, standard deviation, mode, and medians were calculated. Tukey HSD test was used to compare the means in all groups. P < 0. 05 was considered as statistically significant (i. e., 5% significant level). Results: In the experimental groups, the new bone formation was initiated from the margin of defects during the 7– 14 days after implantation. By the end of study, the amount of newly formed bone increased and relatively matured, and almost all of the implanted materials were absorbed. In the control group, slight amount of new bone had been formed at the defect margins (next to the host bone) on day 56. The histomorphometric analysis revealed statistically significant differences in the amount of newly formed bone between the experimental and the control groups (P < 0. 001). Conclusion: Combination of OCP/BMG may serve as an optimal biomaterial for the treatment of mandibular bone defects.

Background. Regeneration of bone defects remains a challenge for maxillofacial surgeons. The present study aimed to com-pare the effects of OCTACALCIUM PHOSPHATE (OCP) and the combination of OCTACALCIUM PHOSPHATE/gelatin (OCP/Gel) on man-dibular bone regeneration in rats Methods. In the present study, 36 male Sprague-Dawley rats were used. The animals were randomly assigned to the follow-ing experimental groups: OCP (n=12), OCP/Gel (n=12), and the control group (n=12). Defects were created in the rat man-dibles and filled with 10 mg of OCP and OCP/Gel disks in the experimental groups. In the control group, however, no sub-stance was administered. Samples were taken on days 7, 14, 21 and 56, respectively, after the implantation. Sections (5 μ ) were prepared and stained by H&E. The sections were studied, and the volume fraction of newly formed bone was measured by Dunnett's T3 test based on the significance level (P=0. 05). Results. In the experimental groups, the new bone formation began from the margin of defects 7‒ 14 days after the implan-tation. During the healing process, the newly formed bone healed a larger area of the defects and grew structurally. In the control group, the defects were primarily filled with dense connective tissue, and only a small amount of new bone was formed. The present study showed a statistically significant difference in the volume of newly formed bone between the experimental groups and the control group (P<0. 001).Conclusion. OCP/Gel composite can be beneficial in the healing process of mandibular bone defects.

Background: Repair of bone defects is challenging for reconstructive and orthopedic surgeons. In this study, we aimed to histomorphometrically assess new bone formation in tibial bone defects filled with OCTACALCIUM PHOSPHATE (OCP), bone matrix gelatin (BMG), and a combination of both. Methods: A total of 96 male Sprague Dawley rats aged 6-8 weeks weighing 120-150 g were randomly allocated into three experimental (OCP, BMG, and OCP/BMG) and one control group (n=24 in each group). The defects in experimental groups were filled with OCP (6 mg), BMG (6 mg), or a combination of OCP and BMG (6 mg, 2: 1 ratio). No material was used to fill the defects in the control group and the defect was only covered with Surgicel. Samples were taken on days 7, 14, 21, and 56 after the surgery. The sections were stained with hematoxylin-eosin (H&E) and assessed using light microscopy. Results: In our experimental groups, bone formation was started from the margins of the defect towards the center with an increasing rate during the study period. Moreover, the formed bone was more mature. Bone formation in our control group was only limited to the margins of the defect. The newly formed bone mass was significantly higher in the experimental groups (P=0. 001). Conclusion: OCP, BMG, and OCP/BMG compound enhanced osteoinduction in long bones.

Background and Aims: The purpose of this study was to evaluate the tissue responses to OCTACALCIUM PHOSPHATE (OCP) and calcium hydroxide (CH) used as direct pulp capping (DPC) materials in cat teeth.Materials and Methods: 72 premolar teeth of 9 cats were selected and divided into 3 groups (Two experimental and one control group). After the cats had been anesthetized, the teeth were exposed and capped directly with OCP, CH or no capping material as control group. The cavities of all three groups were filled with Glass ionomer cement (GI). Histological evaluations were performed at two, four and eight weeks after pulp capping. After tissue preparation procedures, paraffin blocks were prepared. After preparation and staining of the sections, the relevant variables were measured by optical microscope. The results were analyzed using Mann-Whitney U and Chi-square tests (a=0.05).Results: Two weeks after pulp capping, all specimens in three groups showed mild to sever inflammation. The formation of hard tissues (dentinal bridge) initiated in the exposed areas of the experimental groups was more noticeable for calcium hydroxide than that of OCTACALCIUM PHOSPHATE group, These differences were statistically significant (P<0.001). At four weeks, hard tissues were observed in both groups which were more evident for the CH group and there were statistically significant differences between two experimental groups (p<0.003). At eight weeks, continuous hard tissues were observed in both groups and there were no statistically significant differences between them (P>0.05), but hard tissues continuity were better for in the OCP than that of the CH.Conclusion: It seems that the formation of hard tissue in CH because of its porosities had a worse percentage in sealing of the pulp than the OCP.