To date, various clinical procedures have been used to restore periodontal apparatus destroyed by periodontal disease. And then, many experimental approaches have been proceeded to develop treatment methods to promote periodontal regeneration. Mechanical, chemical treatments to enhance the attachment of periodontal tissue cells as changing the physical properties of root surfaces, bone graft procedure, and treatments for guided tissue regeneration have been used for periodontal regeneration. However, recent studies have revealed that biologic factors such as growth factors promote biologic mechanism associated with periodontal regeneration. This study was done to enucleate how ELF stimulus affect the periodontal regeneration. We can have following conclusions from this experimental results. The influence of low frequency(ELF) electric stimulus (30HZ at 10micronA) known to promote bone formation in vivo, was evaluated for its ability to affect bone cell function in vitro. After 12 hour exposure of ELF stimulus at most appropriate densities (5x10(4) cells/cm2) to increase osteoblastic cells normally, rat calvarial cells were incubated for 60 hours were used in this study. We have found ELF stimulus suppress calvarial cell proliferation and the ability of protein synthesis, enhance the alkaline phosphatase activity significantly.
Alkaline Phosphatase ; Animals ; Biological Factors ; Cell Proliferation ; Guided Tissue Regeneration ; Intercellular Signaling Peptides and Proteins ; Osteoblasts ; Osteogenesis ; Periodontal Diseases ; Rats ; Regeneration ; Skull* ; Transplants

The purpose of this study was to evaluate various methods of decontamination of ultrasonic scalers, high-speed handpieces and air-water syringes in dental equipments. Eimination of possible sources of microbial infection in dental operatories should be of primary importance. Microbial contamination levels of high speed handpieces, air-water syringes and ultrasonic scalers of 11 dental units in Seoul National University Hospital were evaluated after flushing the lines, alcohol sponge rubbing, or soaking in 0.1% chlorhexidine for 1,3 and 5 minutes. The result suggests that flushing the lines or soaking the tips in 0.1% chlorhexidine before use of the water systems may reduce the microbial levels. Soaking in 0.1% chlorhexidine for 5 minutes was most effective in reducing bacterial contamination.
Chlorhexidine ; Decontamination ; Dental Equipment ; Flushing ; Porifera ; Seoul ; Syringes* ; Ultrasonics*

This study was performed to evaluate the effect of mixed culture of rat's calvaria cells and periodontal ligament cells on calcification. These cells have been known to do important role on the periodontal tissue regeneration, especially alveolar bone and cementum. Experimental groups were made which based on the different rate of rat's calvaria cells and periodontal ligament cells, and then these cells were cultured with Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum, 50microgram/ml ascorbic acid, and 10mM/ ml Na-beta-glycerophosphate. Each group was characterized by examining the cell proliferation rate, amount of total protein synthesis, alkaline phosphatase activity, and the number of calcified nodules in vitro. In cell proliferation rate , the cells of control groups were cultured Dulbecco's Modified Eagle's Medium contained with 10 % fetal bovine serum. The results were as follows ; 1. The cell proliferation rate in control groups decreased stastically significantly along with the decrease of the rate of bone cells at 7 day and 20 day(P < 0.01). 2. The cell proliferation rate in experimental groups decreased stastically significantly along with decrease of the rate of bone cells at 3 day and 14 day(P < 0.01). 3. The amount of total protein synthesis was significantly decreased along with decrease of the rate of bone cells at 3 day and 6 day(P < 0.01). 4. Alkaline phosphatase activity showed reverse time dependent pattern and was significantly decreased along with decrease of the rate of bone cells during the experimental periods (P < 0.01). 5. Calcified nodules were observed in group 1 (Rat calvaria cells alone) for the first time, and the number of calcified nodule decreased stastically significantly along with the decrease of the rate of bone cells at 12 day(P < 0.01). From the above results, When bone cells and periodontal ligament cells were mixed cultured, the cell proliferation rate was mostly dependent on the actual rate of bone cells and same pattern was showed in amount of total protein synthesis, alkalinephosphatase activity, and the number of calcified nodules. And the calcified nodule forming capacity of bone cells was inhibited by periodontal ligament cells
Alkaline Phosphatase ; Animals ; Ascorbic Acid ; Cell Proliferation ; Dental Cementum ; Periodontal Ligament* ; Rats* ; Regeneration ; Skull*

The purpose of this study was to evaluate the effect of high glucose on prostaglandin E2 production in human gingival fibroblasts and periodontal ligament cells in vitro. In control group, the cells(5x10(4) cells/ml) were cultured with Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum, 45mg/dl glucose. In experimental groups, glucose was added to the above culture condition at the final glucose concentrations of 100mg/dl(Test group 1), 200mg/dl (Test group 2) and 400mg/dl(Test group 3). Then each group was tested for the cell proliferation rate, protein levels, and prostaglandin E2 production at 1/2, 1, 2, 5 days. The results were as follows ; 1. As glucose concentration increased, cell proliferation rate decreased significantly at 1, 2, 5 days in human gingival fibroblasts and periodontal ligament cells(P<0.01). 2. In human gingival fibroblasts, test group 2 and 3 showed significantly decreased protein levels as compared to control group at 5 days(P<0.01). 3. In human periodontal ligament cells, as glucose concentration increased, protein levels decreased significantly at 2 days and 5 days(P<0.01). 4. Prostaglandin E2 production in human gingival fibroblasts and human periodontal ligament cells significantly increased as glucose concentration increased(P<0.01). The results at 5 days showed obvious difference as compared to those at 2 days. From the above results, high glucose appeared to affect cellular activities including cell proliferation rate, protein levels and enhance prostaglandin E2 production. It was assumed that prostaglandin E2 production by high glucose enhances inflammatory reaction and has a toxic effect on human gingival fibroblasts and human periodontal ligament cells. This study suggests that periodontal disease in diabetic patient is related to prostaglandin E2 production.
Cell Proliferation ; Dinoprostone* ; Fibroblasts* ; Glucose* ; Humans* ; Periodontal Diseases ; Periodontal Ligament*

Bone remodeling is characterized by the coupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. The process is tightly regualted at the local level by an incompletely known netwotk of peptide and non-peptide fators. Nitric oxide(NO), synthesized by nitric oxide synthetase(NOS) from L-arginine, is becoming recognized as an important bioregualtory molecule in a variety of tissue, but little is known about its possible role in periodontal tissue. The purpose of this study is to investigate the expression of nitric oxide synthetase(NOS) in inflamed gingiva and the effects of cytokine on the expression of NOS protein. The expression of NOS in gingival tissue was evaluated by immunohistochemical staining for NOS1, NOS2, NOS3. The effect of cytokine on the expression of NOS in human periodontal ligament cells and osteoblast-like HOS cells by western blot analysis. Further, we studied that NO functions in periodontal ligment cells as a regulatory molecule. PDL cells incubated with NOS inhibitor and donor. The protein expression, type I collagen & non-collagenous protein, nitrate production and cell proliferation were evaluated The results were as follows. 1. NOS1, NOS2, NOS3 was rarely distributed in healthy gingiva, but stronger stained in gingival epithelium, endothelial cells, and mononuclear cells of inflammed gingiva. 2. The cytokine stimulated NOS1, and NOS3 protein were not inducing or inhibitory effect to compared with control in PDL and HOS cells. 3.Incubation of cells with combination of TNF-alpha, IFN-gamma, LPS result in a time dependant increase in NOS2 expression, reaching a maximal level after 24 hours of stimulation. 4. The osteonectin protein inhibitory effect of NMA, inhibitor of NOS, was reversed by Larginine in dose dependant manner. 5. NMA decreased cell proliferation and nitrate production, but the inhibitory efffect of NMA was also prevented by the NO donor, sodium nitropruiside. These results suggest that exogenously synthesized NO was playing a stimulating effect on cell proliferation or on non-collagenous protein expression. Therefore NO have an important role in mediation of localized bone destruction associated inflammatory bone disease such as periodontitis
Arginine ; Blotting, Western ; Bone Diseases ; Bone Remodeling ; Bone Resorption ; Cell Proliferation ; Collagen Type I ; Endothelial Cells ; Epithelium ; Gingiva ; Humans ; Negotiating ; Nitric Oxide Synthase* ; Nitric Oxide* ; Osteogenesis ; Osteonectin ; Periodontal Ligament ; Periodontitis ; Sensitivity and Specificity* ; Sodium ; Tissue Donors ; Tumor Necrosis Factor-alpha

Safflower(Carthamus tinctorius Linne'has been traditionally used for the treatment of blood stasis, and Dipsasi Radix has been used as a drug for fracture in Chinese medicine. The purpose of present study was to examine the biologic effects of safflower extract and Disasi radix extracts on the periodontal ligament cells and osteoblastic cells and on the wound healing of rat calvarial defect. The ethanolic extract of safflower blossom, safflower seed and Dipsasi Radix(125, 250, and 500 microgram/ml) were prepared as test group, and PDGF-BB(10ng/ml) and unsafonifiable fraction of Zea Mays L.(125, 250, and 500 microgram/ml) were employed as positive control. The effects of each agents on the growth and survival, ALPase activity, expression of PDGF-BB receptor, chemotactic response of PDL cell and ATCC human osteosarcoma MG63 cells in vitro were examined. The tissue regenerative effect of each extracts was evaluated by histomorphometric measuring of newly formed bone on the 8mm defect in rat calvaria after oral administration of 3 different dosages groups : 0.02, 0.1 and 0.35g/kg, per day. It was also employed the same dosages of unsaponifiable fraction of Zea Mays L. as positive controls. Safflower blossom extract, safflower seed extract, and Dipsasi Radix extract stimulate the cellular activity of MG63 cells in concentration range of 125-500microgram/ml, and safflower bolssom extract and safflower seed extract stimulate also the cellular activity of periodontal ligament cells in concentration range of 250-500microgram/ml. In activity of ALPase, 250-500microgram/ml of safflower blossom extracts showed significant stimulating effects on MG63 cells, and the same concentration range of safflower seed extracts showed significant effect on periodontal ligament cells. In the recovery on PDGF-BB receptor expression which was depressed by IL-1beta, 125-250microgram/ml of safflower blossom extracts and 250-500microgram/ml of safflower seed extracts showed significant increasing effect on MG63 cells, and 500microgram/ml of safflower blossom extract and 250-500 microgram/ml of safflower seed extracts showed significant effect on periodontal ligament cells. In chemotactic response, among all tested group, safflower seed extracts only were chemotactic to MG63 cells and periodontal ligament cells in concentration range of 125-500 microgram/ml. Also in the view of bone regeneration in rat calvarial defect model, the only group that was orally administrated 0.35g/kg, day of safflower seed extract showed significant new bone formation. These results suggested that safflower extracts might have a potential possibilities as an useful drug for adjunct to treatment for regeneration of periodontal defect.
Administration, Oral ; Animals ; Asian Continental Ancestry Group ; Bone Regeneration ; Carthamus tinctorius ; Ethanol ; Flowers ; Humans ; Osteoblasts* ; Osteogenesis ; Osteosarcoma ; Periodontal Ligament* ; Rats ; Regeneration ; Skull ; Wound Healing ; Zea mays

Several experimental studies showed that the application of small amounts of electric current to bone stimulated osteogenesis at the site of the cathode and suggests that the application of electrical currents to periodontal defects could promote bone and cementum formation. The purpose of this study was to determine the effect of direct microcurrent to the periodontal regeneration of class III furcation defects in dogs. Class III furcation defects were surgically created on the third and the fourth premolars bilaterally in the mandibles of nine mongrel dogs. Experimental periodontitis were induced by placing small cotton pellets into the created defects for 3 weeks. The experimental sites were divided into three groups according to the treatment modalities: Group I- surgical debridement only; Group II- allogenic demineralized freeze dried bone grafting; Group III- allogenic demineralized freeze dried bone grafting and electrical stimulation. For fluorescence microscopic evaluation, calcein, oxytetracycline HCl and alizarin red were injected 2, 4 and 8 weeks(3 days prior to sacrifice) after surgery. The animals were sacrificed in the 1st, 2nd, 4th and 8th week after periodontal surgery and the decalcified and undecalcified specimens were prepared for histological and histometrical examination. After the first and the second weeks, gingival recession was more severe in group I than groups II and III. After the fourth and the eighth weeks, there was no difference in the width of junctional epithelium and connective tissue attachment among the three groups, but the width of connective tissue attachment increased in group II at the eighth week, compared to the fourth week. The amount of bone repair in new attachment was significantly greater in group III, compared to groups I and II. New attachment formation was significantly greater in group III, compared to groups I and group II. These results suggest that electrical stimulation using microcurrent generator could be a useful tool for periodontal regenerative therapy in class III furcation defect.
Animals ; Bicuspid ; Bone Transplantation ; Connective Tissue ; Debridement ; Dental Cementum ; Dogs ; Electric Stimulation ; Electrodes ; Epithelial Attachment ; Fluorescence ; Furcation Defects* ; Gingival Recession ; Mandible ; Osteogenesis ; Oxytetracycline ; Periodontitis ; Regeneration*

Dentin hypersensitivity must be one of the most frequent postoperative complaints in periodontal patients. Obliterating the open dentinal tubules or decreasing the diameter of their orifices would, therefore, be an objective of treatment for hypersensitive teeth. The purpose of this study was to evaluate the effect of a pulsed Nd:YAG laser irradiation on obliteration of dentinal tubules and to determine any difference according to irradiation methods. The 45 posterior teeth that had been extracted due to periodontal disease were initially treated with tetracycline HCl(100 mg/ml, 4 min.) to remove the smear layer after root planing. The root surfaces were then irradiated by a pulsed Nd:YAG laser(EL.EN.EN060, Italy) by different laser beam spot size and different exposure condition; group 1: irradiated group by small spot(beam diameter=1mm, 1W, 2 sec) group 2: irradiated group by large spot(beam diameter=10mm, 1W, 200 sec) group 3: irradiated group by gradual increase of watt(from 0.3W to 1.0W), beam diameter=4mm group 4: irradiated group by fixed watt(1.0 W), beam diameter= 4mm control group: no irradiation but root planing and tetracycline HCl conditioning only. Additionally, the specimens were retreated with tetracycline HCl(100mg/ml, 4min.) to evaluate the stability of obliteration effect by Nd:YAG laser. Specimens were examined under the scanning electron microscope(JEOL, JSM-840A, Japan). Photomicrographs were taken at x4,000 magnification and were analyzed statistically. The results were as follows; 1. Scanning electron micrographs of root surface treated by tetracycline HCl alone(control group) showed widened, funnel-shaped dentinal tubules, while those of the root surface irradiated by various methods showed partially or completely obliterated dentinal tubules and various surface alterations, eg, flat, multiple pitted, melted and resolidified surface at the same energy density. 2. There was no significant difference in the obliteration effect of dentinal tubules between group 1 and group 2, and between group 3 and group 4(p>0.05). 3. The obliteration effect of dentinal tubules by a Nd:YAG laser irradiation was relatively stable to tetracycline HCl. The results demonstrate that a pulsed Nd:YAG laser irradiation within 1.0W, regardless of irradiation methods, can obliterate dentinal tubules effectively.
Dentin Sensitivity ; Dentin* ; Humans ; Periodontal Diseases ; Root Planing ; Smear Layer ; Tetracycline ; Tooth

The purpose of this study was to evaluate the abrasion-resistance of root surface after NaF iontophoresis, Nd:YAG laser irradiation and combined treatment 50 anterior teeth with flat interproximal root surface that had been extracted due to periodontal destruction were selected. All teeth were treated by the same procedure as conventional periodontal root treatment, such as scaling and root planing, root conditioning with tetracycline HCl(100mg/ml, 5min). The pre-treatment weight of each tooth was measured by a dial scale(SHIMADEU Co., LIBROR EB-220HU, capacity 220.000 g, Japan). All teeth were divided into 5 groups as follows; Nd:YAG laser irradiation(group 1, 1 W, 100 mJ, 10Hz, fiberoptic-root surface distance=5mm, 10 sec.x6times, EL.EN.EN060, Italy); NaF iontophoresis(group 2, 150micronA, 4 min.); Nd:YAG laser irradiation following NaF iontophoresis(group 3); NaF iontophoresis following Nd:YAG laser irradiation(group 4); No treatment(control group). Electric toothbrushing (Oral-B, Brown Co., Germany) was conducted during 1 hour(10 min.x6 times). Subsequently post-treatment weight was remeasured by the same method as pre-treatment weight measurement. The difference of abrasion rate among all groups was statistically analyzed by ANOVA(SAS program). Following results were obtained; 1. The abrasion rate was significantly lower in Nd:YAG laser irradiation group than NaF iontophoresis group(p < 0.001). 2. The abrasion rate was significantly lower in combined groups of Nd:YAG laser irradiation and NaF iontophoresis than either Nd:YAG laser irradiation group or NaF iontophoresis group(p < 0.001). 3. There was no significant difference in abrasion rate according to application order in the combined groups(p > 0.05). 4. The abrasion rate was significantly lower in all experimental groups than control group(p < 0.001). The results suggest that combined treatment of Nd:YAG laser irradiation and NaF iontophoresis on exposed root surface after periodontal therapy can enhance the abrasion-resistance of root surface and may inhibit the root caries development.
Iontophoresis* ; Root Caries ; Root Planing ; Tetracycline ; Tooth ; Toothbrushing

The purpose of this study is to evaluate histologic result of bone substituting material on defects followed tooth extraction. We compare the histologic findings control, DFDBA, Bio-Oss(R), and Regenafil(TM), Briefly, mandibular premolar teeth were extracted available for bone filling. All alveolar sites were checked after extraction and thoroughly debrided with a dental curet to remove the periodontal ligament. Extraction sites were prepared dehiscence on buccal side 7mm height from alveolar crest. The graft materials were filled into the extraction socket and dehiscenc defects. The animals were sacrificed 12 weeks after implantation. Both treated and control mandibular sites were histologically evaluated with light microscopy. Histologic observation at 12 weeks revealed that control and experimental sites were healed uneventfully and directly apposed to new bone without any adverse tissue reaction. DFDBA and Bio-Oss(R) sites maintain width of alveolar crest but were not fully resorbed. Regenafil(TM) sites also maintain width and particles were resorbed more than other graft materials. From this results, it was suggested that Regenafil(TM) is promising boen substituting materials maintaining the width of alveolar crest and height follewed tooth extraction.
Animals