The purpose of this study was to develop an osteogenic, biodegradable material using polymer and BMP. It was designed to have structural function and be moldable, for the reconstruction of load bearing areas and deformities of various configurations. Bone apatite was added to Poly(L-lactide)(PLLA) and made porous for osteoconductability and ease of BMP loading. The materials, with or without BMP purified from porcine bone matrix, were evaluated in cranial bone defect models in rats for biocompatibility and bone regeneration capability. The following results were obtained: The PLLA-BMP material with BMP added to the polymer showed 30% healing of cranial bone defects in rats during the 2 weeks to 3 months period of observation. The moldable PLLA agent without BMP also showed 25% bone healing capacity. Although new bone formation was incomplete in the critical size defect of rat cranium, it can be concluded that the unique moldability of those agents makes them useful for the reconstruction of various bone defects and maxillofacial deformities.
Animals ; Bone Matrix ; Bone Morphogenetic Proteins* ; Bone Regeneration ; Congenital Abnormalities ; Osteogenesis ; Polymers* ; Rats ; Skull ; Weight-Bearing

Using barrier membrane, guided bone regeneration(GBR) and guided tissue regeneration(GTR) of periodontal tissue are now widely studied and good results were reported. In bone regeneration, not all cases gained good results and in some cases using GTR, bone were less regenerated than that of control. The purpose of this study is to search for the method to improve the success rate of GBR and GTR by examination of the cause of the failure. For these study, rats and beagle dogs were used. In rat study, 5mm diameter round hole was made on parietal bone of the rat and 10mm diameter of bioresorbable membrane was placed on the bone defects and sutured. In 1, 2, 4 weeks later, the rats were sacrificed and Masson-Trichrome staining was done and inspected under light microscope for guided bone regeneration. In dog study, 3x4mm2 Grade III furcation defect was made at the 3rd and 4th premolar on mandible of 6 beagle dogs. The defects were covered by bioresorbable membrane extending 2-3mm from the defect margin. The membrane was sutured and buccal flap was covered the defect perfectly. In 2, 4, 8 weeks later, the animals were sacrificed and undecalcified specimens were made and stained by multiple staining method. In rats, there was much amount of new bone formation at 2 weeks, and in 4 weeks specimen, bony defect was perfectly closed and plenty amount of new bone marrow was developed. In some cases, there were failures of guided bone regeneration. In beagle dogs, guided tissue regeneration was incomplete when the defect was collapsed by the membrane itself and when the rate of resorption was so rapid than expected. The cause of the failure in GBR and GTR procedure is that 1) the membrane was not tightly seal the bony defects. If the sealing was not perfect, fibrous connective tissue infiltrate into the defect and inhibit the new bone formation and regeneration. 2) the membrane was too tightly attached to the tissue and then there was no space to be regenerated. In conclusion, the requirements of the membrane for periodontal tissue and bone regeneration are the biocompatibility, degree of sealingness, malleability, space making and manipulation. In this animal study, space making for new bone and periodontal ligament, and sealing the space might be the most important point for successful accomplishment of GBR and GTR.
Animals ; Bicuspid ; Bone Marrow ; Bone Regeneration ; Connective Tissue ; Dogs ; Furcation Defects ; Guided Tissue Regeneration ; Mandible ; Membranes ; Osteogenesis ; Parietal Bone ; Periodontal Ligament ; Rats ; Regeneration

The purpose of this study was to evaluate the effects of ethanolic extracts of Scutellaria Radix on the alveolar bone formation in the extract socket of rat. Thirty-six Sprague-dawley rats were used in this study. Mean body weight of rat was 130+/-5g. Experimental animal were administered 0.4% beta-aminopropionitril(Sigma, USA) with the solid commercial food for 5 days. All the maxillary 1st molar of the rats were extracted by using of the tissue forcep under the general anesthesia with Pentobarbital sodium(Tokyo Chemical Co., Japan) injection into intraperitoneal space. All the extracted rats were divided into two group, experimental group which were feeded the solid food mixed ethanolic extracts of Scutellaria Radix, and control group which were feeded same food without reagent. At 1, 3, 5, 7, 9 and 14th days after tooth extraction, rats in both groups were serially sacrificed respectively. All the specimen were treated as usual method and prepared Hematoxylin-eosin stain for the light microscopic observation. The results were as follows : 1. Bone formation of extracted socket starts from the area on remained periodontal ligament than other area. 2. In the case of administration of the extracted Scutellaria Radix showed rapid healing process of connective tissue than non-administrated group. 3. In the case of administration of the extracted Scutellaria Radixshowed rapid osteogenesis than non-administrated With above results, it was concluded that ethanolic extracts of Scutellaria Radix may play a favorable role on the healing process of exatraction socket after extraction in rats. It was suggested that further study to evaluate the different concentration and administration method of ethanolic extracts of the Scutellaria Radix into same experimental model.
Anesthesia, General ; Animals ; Body Weight ; Connective Tissue ; Ethanol* ; Models, Theoretical ; Molar ; Osteogenesis* ; Pentobarbital ; Periodontal Ligament ; Rats* ; Rats, Sprague-Dawley ; Scutellaria* ; Surgical Instruments ; Tooth Extraction

Finite element analyses were performed to study effects on stress distribution generated in jaw bone for various shapes of dental implants: plateau type, plateau with small radius of curvature, triangular thread screw type in accordance with ISO regulations and square thread screw filleted with small radius partially. It was found that square thread screw filleted with small radius was more effective on stress distribution than other dental implants used in analyses. Additional analyses were performed on the implant with square thread screw filleted with small radius for verying design parameters, such as the width of thread end, the height of the thread of the implant and load direction, to determine the optimum dimensions of the implant. The highest stress concentration occurred at the region in jaw bone adjacent to the first thread of the implant. The maximum effective stress induced by a 15 degree oblique load of 100 N was twice as high as the maximum effective stress caused by an equal amount of vertical load. Stress distribution was more effective in the case when the width of thread end and the height of thread were p/2 and 0.46p, respectively, where p is the pitch of thread. At last, using tensile force calculated from the possible insert torque without breading bone thread, finite element analysis was performed on the implant to calculate pre-stress when the primary fixation of the implant was operated in jaw bone. The maximum effective stress was 136.8 MPa which proven to be safe.
Bread ; Dental Implants ; Finite Element Analysis ; Jaw ; Radius ; Social Control, Formal ; Torque

In order to find out the distribution of fibronectin and fibrinogen in placenta among pregnancy induced hypertensive (PIH) patients, 6 normotensive pregnancies and 17 PIH patients were chosen. The placentas were obtained right after delivery and soaked in the 10% formalin solution. The score was measured in terms of the positiveness of the stain in immunohistochemical stain by using I antibody with the rabbit antihuman fibronectin and the rabbit anti-human fibrinogen. Comparison between two groups are as following: 1.The placenta of PIH patients showed significantly reduced positiveness of fibronectin in their fetal villous vessels and villous stroma. 2. In the PIH patients, the positiveness was reduced in the group giving the birth to intrauterine fetal growth retardation compared to giving birth to normal baby. 3. In both normotensive and PIH patients, the villous basement membrane did not show the staining response to fibronectin, while showing heavy staining response to fibrinogen. 4. The positiveness of fibrinogen in fetal vessels, villous basement membrane, intervillous space and stroma were almost same in both normotensive and PIH patients. From above results, we can conclude that there is abnormality in the distribution of fibronectin especially in the fetal vessels and the villous stroma of placenta among PIH patients. The cause of this result needs further study.
Basement Membrane ; Fetal Growth Retardation ; Fibrinogen* ; Fibronectins* ; Formaldehyde ; Humans ; Parturition ; Placenta* ; Pre-Eclampsia ; Pregnancy*

No abstract available.
Child* ; Humans ; Proteinuria*

No abstract available.

OBJECTIVES: The purpose of this study is to analyze the previously unreported effect of fetal sex on the fetal heart rate and to measure its magnitude in relation to the effects of other independent clinical variables. METHODS: Three hundred and seventeen pregnant women who were able to provide electronic fetal heart rate monitoring were evaluated. On the basis of fetal sex after birth, 167 pregnant women who delivered male neonate were for males group and 146 examples who delivered female neonate were for female group. We analyzed fetal heart rate data using the Catholic Computer Assisted Obstetric Diagnosis System(CCAOD). RESULTS: Female fetuses had significantly faster basal heart rate(140.51+/-12.43bpm) than male fetuses(137.64+/-13.68 bpm).(P=0.007) Percent acceleration time(PAT) increased significantly for males(6.10+/-4.00bpm), comparing to females(4.90+/-3.34bpm).(P=0.001) Also percent deceleration time(PDT) was significantly higher in male fetuses(7.50+/-8.70bpm) than female fetuses(6.18+/-7.70bpm).(P=0.039) But there was no differences in standard deviation(SD)(8.84+/-10.11bpm, 8.11+/-3.56bpm), long term variation(LTV)(80.38+/-62.79msec, 73.65+/-54.60msec), and short term variation(STV)(14.06+/-9.79msec, 13.33+/-12.32msec) between male and female fetuses. CONCLUSION: The fetal heart rate of female fetuses differ from that of male fetuses. Computerized linear analysis and nonlinear analysis of antepartum fetal heart rate will need to take into account the multiple factors that influence the fetal heart rate to identify precisely which pattern predict clinical outcome.
Acceleration ; Deceleration ; Diagnosis ; Female ; Fetal Heart* ; Fetus ; Heart ; Heart Rate, Fetal* ; Humans ; Infant, Newborn ; Male ; Parturition ; Pregnancy ; Pregnant Women

4 beagle dogs aged over one and half years and weighed 15 to 16 Kg were utilized in this study. Experimental dehiscent defects were made in the mandibular edentulous area after removal of lower premolar. e-PTFE membrane resorbable membrane, and PDGF-BB-loaded resorbable membrane were covered at the dehiscent defects around the dental implants respectively. Animal was sacrificed at 1, 2, 3 months respectively. Non-decalicifed specimens were made and mutiple-stained for light microscopic study. The results were as follows: 1. Dehiscent defects around the implant installed in the beagle dog were an excellent defect model for studying guided bone regeneration. 2. Fibroblasts penetrated into expanded-PTFE membrane was observed and inflammatory cell infiltration was also observed around the membrane. 3. Resorbable membrane was degradaded and resorbed at 1 month after application to the dehiscent defect. Though multinucleated giant cells were observed adjacent to the membrane, that had no reverse effect on the bone regeneration. 4. PDGF-BB-loaded resorbable membrane was same capability as the resorbable membrane and e-PTFE membrane in the guided bone regeneration. 5. PDGF-BB-loaded resorbable membrane-applied site was better than resorbable membrane-applied site in the speed and maturity of bone formation. Within the above results, it was suggested that PDGF-BB-loaded resorbable membrane might have same bone regeneration capacity as nonresorbable membrane in the dehisced implant of the beagle dog and potentiality to use in human subjects.
Animals ; Bicuspid ; Bone Regeneration* ; Dental Implants ; Dogs* ; Fibroblasts ; Giant Cells ; Humans ; Membranes* ; Osteogenesis

PURPOSE: The aim of this study was to investigate the effects of EMD on demineralized root surface using human periodontal ligament cells and compare the effects of root conditioning materials(tetracycline(TCN), EDTA). MATERIAL AND METHODS: Dentin slices were prepared from the extracted teeth and demineralized with TCN and EDTA. Demineralized dentin slices were incubated at culture plate with 25, 50 and 100 microgram/ml concentration of EMD. Cell attachment, alkaline phosphatase activity test, protein synthesis assay and scanning electronic microscopic examination were done. RESULTS: Cells were attached significantly higher in EMD treated group at 7 and 14 days. Cell numbers were significantly higher in EMD treated group. Alkaline phosphatase activity was significantly higher in EMD treated group at 7 and 14 days. Protein synthesis was significantly higher in EMD treated group at 7 and 14 days. CONCLUSION: Enamel matrix derivatives enhance the biologic activities of human periodontal ligament cells on demineralized root surface and its effects are dependent on the concentration of EMD.
Alkaline Phosphatase ; Cell Count ; Dental Enamel ; Dentin ; Edetic Acid ; Electronics ; Electrons ; Humans ; Periodontal Ligament ; Tetracycline ; Tooth