Papers by Author: Ui Won Jung

Abstract: The purpose of this study was to evaluate the osteogenesis of tetracycline blended chitosan membranes on the calvarial critical size defect in Sprague Dawley. An 8 mm surgical defect was created with a trephine bur in the area of the midsagittal suture. Forty rats were divided into four groups: negative control group, positive control group and two experimental groups. Three types of membranes were made and a comparative study was done. One type of non-woven membrane was made by chitosan for positive control. The other two types of non-woven membranes were made by immersing non-woven chitosan into either the tetracycline solution or the chitosan-tetracycline solution. Histologic analysis was done at 2 weeks and 8 weeks of healing periods. We concluded that that the use of tetracycline blended chitosan membrane on the calvarial defects in rats has a significant effect on the regeneration of bone tissue in itself. In addition it implicates that tetracycline blended chitosan membrane may be useful for guided tissue regeneration.

Abstract: This study evaluated periodontal repair and biomaterial reaction following implantation of a newly fabricated calcium phosphate chitosan block bone and chitosan membrane on the regeneration of 1- wall intrabony defects in the beagle dogs. The surgical control group received a flap operation only, while experimental group was treated with calcium phosphate chitosan block bone and/or chitosan membrane. All dogs were uneventful healing without any complication. The subjects were sacrificed 8 weeks after the experimental surgery, and a comparative histological and histometric examination was done. Chitosan membrane group significantly enhanced bone regeneration compared to control, CaP-chitosan block bone and combination group. Chitosan membrane remnants were observed in chitosan and combination group, while CaP-chitosan bone materials were resorbed completely. These results suggest that Chitosan membrnae significantly enhanced bone and cementum formation in advanced periodontal defects.

Abstract: The aim of this study was to evaluate the regenerative effects of chitosan membranes containing tetracycline (TC) applied to surgically created one-wall intrabony defects in beagle dogs. The defects either received chitosan membrane (CH), chitosan membrane containing 0.5%, 1% TC (CH-TC0.5, CH-TC1.0) or flap operation only. The animals were sacrificed 8 weeks after the experimental surgery, and comparative histological and histometric examinations were done. The amount of junctional epithelium migration and connective tissue adhesion did not show any statistically significant differences among the groups. The amount of new cementum regeneration, and new bone regeneration were significantly greater in CH-TC1.0 group than the control (P<0.05). The results suggest that chitosan membrane combined with 1.0% TC may have beneficial effect on the regeneration of bone and cementum in intrabony periodontal defects.

Abstract: The purpose of this study was to evaluate the effects of collagen membrane coated with PLGA on bone regeneration in rat calvarial defect. Five groups of 10 animals each received either collagen membrane coated with 0.5%, 1%, 3% concentration of PLGA, collagen membrane only or surgical control. Each group of animals was healed into 2 healing periods of 2(5 animals) and 8(5 animals)weeks and histologic and histomorphometric analysis were done. The results of the following study revealed that surgical implantation of collagen membranes coated with PLGA enhanced local bone formation at both 2 and 8 weeks independent of different PLGA concentrations. In conclusion, collagen membrane coated with PLGA shows a significant bone formation behavior irrespective of their concentration.

Abstract: The purpose of this study was to evaluate histologically the effect of LiF-maleic acid added calcium aluminate (LM-CA) bone cement and calcium aluminate-polymethylmethacrylate (CA-PMMA) composite bone cement on bone regeneration in rat calvarial defect. After calvarial defects in 8 mm in diameter were created, three groups of 10 animals, a total of 30, each either received LM-CA bone cement, CA-PMMA composite bone cement or a sham-surgery control. Histologic analysis was done at 2 weeks and 8 weeks of healing periods. We concluded that LM-CA bone cement can be used as a bioactive bone graft material due to ability of bonding to the existing bone and CA-PMMA can be used as a graft material for augmentation of bone-volume due to dimensional stability.

Abstract: The aim of this study is to evaluate the effects of coating implants with hydroxyapatite (HA) by an ion beam-assisted deposition (IBAD) method and to compare them with implants prepared with machined and anodized surfaces. Twenty-four implants in this study were divided into three groups; machined, anodized, anodized plus IBAD surface implants. Implant stability and osseointegration were assessed by resonance frequency analysis (RFA) and histologic analysis. We can conclude that implants coated by HA by IBAD demonstrate characteristics of contact osteogenesis, but the research design does not permit conclusions regarding long-term treatment outcome with implants. Further studies are needed.

Abstract: This study evaluated the effects of mixture of fibrin-fibronectin sealant system(FFSS) and calcium carbonate(CC) in periodontal intrabony defects. Thirty six sites with two or three wall intrabony defect were used. 14 defects treated with periodontal flap surgery were assigned as the control group. 11 defects treated with CC implantation were designed as experimental group 1 and 11 defects, treated with CC and FFSS implantation as experimental group 2. The control and experimental groups all achieved statistically significant improvements in probing depth and clinical attachment level from the baseline (P<0.01). In mean postsurgery probing depth and gingival recession reduction, there were no statiscally significant differences between the experimental groups and the controls. However, mean postsurgery clinical attachment levels of both experimental groups improved significantly more than that of the controls. As a result, we suggest that mixture of FFSS and CC can be used effectively in intrabony defect as osteoconductive materials.

Abstract: Dehiscence bone defects, frequently observed on dental implants placed in periodontitis-affected alveolar bone or extraction sockets were treated with β-tricalcium phosphate (β –TCP) and chitosan membrane for guided bone regeneration, and the new bone formation on the treated sites were studied. Beagle dogs were used for the experiment. First to fourth mandibular premolars were extracted, and the post extraction alveolar bone surface was planed. After 8 weeks of healing, 3 by 4mm dehiscence defects were created using straight fissure burs. Total of 16 oxidized titanium surface implants were placed on the bone defects of the subjects, two on each side. Control sites were treated with implants only. Experimental Group 1 sites were treated with implants and chitosan membrane. Experimental Group 2 sites were treated with implants, β-TCP and chitosan membrane. Experimental Group 3 sites were treated with implants, β-TCP, autogenous bone and chitosan membrane. The animals were sacrificed 12 weeks after implant placement, and the specimens from the treated sites were histologically studied with following results. Limited amount of new bone formation was observed in control group with unexposed membrane. Slightly greater amount of bone formation was observed on sites treated with β-TCP+membrane or autogenous bone+ β-TCP+membrane compared to control group. Remnants of chitosan membrane and β-TCP encapsulated with connective tissue were observed during experimental periods. These results suggest that further studies are needed on membrane rigidity and infection control for space maintenance underneath the membrane and bone substitutes in the treatment of dehiscence defects.

Abstract: The purpose of this study is to evaluate the effect of paste type calcium sulfate on the epithelial migration, alveolar bone regeneration, cementum formation and gingival connective tissue attachment in intrabony defect in dogs. These results suggest that the use of paste type calcium sulfate in 3-wall intrabony defects has significant effect on new cementum formation , but doesn't have any significant effect on the prevention of junctional epithelium migration and new bone formation. As a result, the paste type calcium sulfate that is used in this study is suggested to be the material that can have a significant effect on the periodontal healing, if its biocompatibility is improved.