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: In order to evaluate bone induction and repair in cranial bone defects by the use of combination of OCTACALCIUM PHOSPHATE/Bone Matrix Gelatin ((OCP)/BMG), this study was conducted.Materials and Methods: We used 40 young male Sprague dawley rats (5-6 weeks age). A full thickness standardized trephine defect, 5mm in diameter, was made in the rat parietal bone and (OCP) combined with BMG was implanted into the defect. No (OCP)/BMG particles were implanted in control group that was otherwise treated identically. On the 5th, 7th, 14th, and 21st days after implantation, the rats were killed and bone samples collected. After processing the tissues by routine histological procedures, 5μm thick sections of bone were cut and stained with Haematoxyline and Eosin (H& E) and alcian blue and examined by light microscope.Results: On the 5th day after implantation, inflammatory cells were seen around the implanted materials, especially around the (OCP) particles. A few clusters of cartilage cells were observed between the BMG particles in the central position of defects on the 7th day after implantation. On the 14th day after implantation, osteogenesis was seen at the margins of the defects. In addition to bone formation from the margins toward the center, interstitial growth of new bone tissue was seen around the implanted materials. By the end of 21st day, almost all of the (OCP)/BMG particles were absorbed and bone trabeculae, bone marrow cavities and bone marrow tissues were seen. In the control group, at the end of 21th day, a few areas of new bone were seen near to the defect margins and host bone, but much less than in the experimental group.Conclusion: Therefore, implants of (OCP)/BMG appear to stimulate new bone growth in bone defects and these biomaterials could be used in the repair of cranial bone defects and injuries in clinical situations.

Statement of Problem: Several methods are used to enhance bone repair and new bone formation, and bone matrix gelatin (BMG) is recently introduced. Purpose: The purpose of this histologic and histomorphometric study was to assess the osteogenic potential and the quantity of new trabecular bone formation after implantation of (OCP) and BMG alone and in combination into the cranial defects in rat. Materials and Methods: In this experimental study, 100 young male Sprague Dawley rats (5-6 weeks age and 120-150gr weight) were divided into four groups randomly. A full thickness standard trephine defect 5mm in diameter was made in the rat's parietal bone, and 5mg of (OCP), BMG alone and in combination were implanted into the defects. No (OCP) and BMG particles were implanted in control group which was otherwise treated identically. On the 5th, 7th, 14th, 21st and 56th days after implantation, the rats were killed and bone samples collected. After processing the samples by routine histological procedures, 5µm thick sections of bone were cut and stained with Haematoxyline & Eosin (H&E) and Alcian Blue and studied histologically and histomorphometrically using light microscope and eyepiece graticule. The amount of newly formed bone was quantitatively measured by the use of histomorphometric methods. Data were analyzed with SAS statistical package using ANOVA and Duncan tests.Results: In the experimental groups, the new bone formation was initiated from the margin of defects during 5-14 days after implantation. During 14-21 days after implantation, bone marrow cavities and bone marrow tissues in newly formed bone were seen. By the end of the study, the newly formed bone increased and was relatively matured and almost all of the implanted materials were absorbed. In control group, at the end of the study, a few clusters of new bone were seen near to the defect margins and host bone. The histomorphometric analysis indicated statistical significant differences in the amount of newly formed bone between the experimental and control groups (P<0.05).Conclusion: Implants of (OCP)/BMG appear to stimulate bone induction and new bone growth in bone defects greater than the other groups and these biomaterials could be used in the repair of cranial bone defects in clinical situations.

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 purpose: This study was designed to identify the cells involved in the healing of the parietal bone defects after implantation of OCTACALCIUM PHOSPHATE ((OCP)) combined with bone matrix gelatin (BMG).Materials and Methods: Sixteen young male Sprague Dawley rats (5-6 weeks age) were used. A full thickness standardized trephine defects, 5mm in diameter, was made in the rat parietal bone and (OCP) combined with BMG (in 1/4 ratio) was implanted into the defect. No (OCP)/BMG particles were implanted in control group that was otherwise treated identically. Cellular identification was carried out on days 7th and 14th after implantation, by light and transmission electron microscopy.Results: Ultrastractural identification of cells involved in the healing of the defects in experimental group on day 7th after implantation, showed full secretary chondroblasts and also showed the integration of newly formed matrix with the defect margins. On day 14th after implantation the results revealed the typical osteoblasts that are active in the defect margins.Conclusion: In experimental group, bone defects were healed through intramembranous ossification route.

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.