The Effect of Interleukin 1-beta, Platelet Derived Growth Factor-BB and Transforming Growth Factor-betaon the expression of PDLs17 mRNA in the Cultured Human Periodontal Ligament Fibroblasts / 대한치주과학회지

The molecular mechanisms control the function of PDL(periodontal ligament) cells and/or fibroblasts remain unclear. PDLs17, PDL-specific gene, had previousely identified the cDNA for a novel protein from cultured PDL fibroblasts using subtraction hybridization between gingival fibroblasts and PDL fibroblasts. The purpose of this study was to determine the regulation by growth factors and cytokines on PDLs17 gene expression in cultured human periodontal ligament cells and observe the immunohistochemical localization of PDLs17 protein in various tissues of mouse. Primary PDL fibroblasts isolated by scraping the root of the extracted human mandibular third molars. The cells were incubated with various concentration of human recombinant IL-1beta, PDGF-BB and TGF betafor 48h and 2 weeks. At each time point total RNA was extracted and the levels of transcription were assessed by reverse transcription-polymerase chain reaction (RT-PCR assay). Polyclonal antiserum raised against PDLs17 peptides, CLSVSYNRSYQINE and SEAVHETDLHDGC, were made, and stained the tooth, periodontium, developing bone, bone marrow and mid-palatal suture of the mouse. The results were as follows. 1. PDLs17 mRNA levels were increased in response to PDGF (10ng/ml) and TGF beta(20ng/ml) after treatment of the IL-1beta, PDGF-BB and TGFbetafor 48 h. 2. PDLs17 was up-regulated only by TGFbeta(20 ng/ml) after treatment of the IL-1beta, PDGF-BB and TGF betafor 2 weeks and unchanged by the other stimulants. 3. PDLs17 was a novel protein coding the 142 amino acid peptides in the ORF and the nucleotide sequences of the obtained cDNA from RT-PCR was exactly same as the nucleotides of the database. 4. Immunohistochemical analysis showed that PDLs17 is preferentially expressed in the PDL, differentiating osteoblast-like cells and stromal cells of the bone marrow in the adult mouse. 5. The expression of PDLs17 protein was barely detectable in gingival fibroblasts, hematopoetic cells of the bone marrow and mature osteocytes of the alveolar bone. These results suggest that PDLs17 might upregulated by PDGF-BB or TGFbetaand acts at the initial stage of differentiation when the undifferentiated mesenchymal cells in the bone marrow and PDL differentiate into multiple cell types. However, more research needs to be performed to gain a better understanding of the exact function of PDLs17 during the differentiation of bone marrow mesenchymal and PDL cells.

Expression of Periostin and S100A2- S100A4-Calcium Binding Proteins mRNA in Human Gingival Fibroblasts and Periodontal Ligament Fibroblasts / 대한치주과학회지

Gingival fibroblasts(GF) and periodontal ligament fibroblasts(PDLF) are the major cellular components of periodontal soft connective tissues, but the precise molecular biological differences between these cells are not yet known. In the present study, we investigated the expression of S100A4, S100A2 calcium-binding protein and osteoblast-specific factor 2(OSF-2, Periostin) mRNA in GF and PDLF in vitro through the process of reverse transcription-polymerase chain reaction(RT-PCR) and Northern blot analysis in each. Human GF and PDLF were isolated from the gingival connective tissue and the middle third of freshly extracted healthy third molars. They were cultured in Dulbecco's Modified Eagle Medium(DMEM) containing 10% fetal bovine serum and cells in the third passage were used in the experiments. After extracting total RNA from cultured cells, RT-PCR and Northern analysis were performed using S100A4-, S100A2- and Periostin-specific oligonucleotide primers and subcloned cDNA probes in each. In RT-PCR and Northern analysis, the expression of S100A4 and Periostin mRNA in GF was slightly detectable. Interestingly, the expression of S100A4 and Periostin mRNA in PDLF was much higher than that in GF. On the other hand, S100A2 mRNA was highly expressed in both GF and PDLF. Since there was a marked difference of S100A4 and Periostin expression between GF and PDLF in vitro, these data suggest that S100A4 and Periostin could be used as a useful marker for distinguishing cultured gingival fibroblasts and periodontal ligament cells.

Investigation of Age and Treatment Modalities in the Periodontally Treated(1981-1995) Patients / 대한치주과학회지

The aim of this study was to recommend the optimal age for prevention of periodontal disease and to investigate the trend of treatment modality according to different period. From the chart recordings of the patients who had been treated periodontally from Jan. 1981 to Dec. 1995 in the dept .of periodontics, Chosun University Dental Hospital, those of the periodontally treated patients on more than 4 sixtants were selected for the present study. The distribution of the patients was counted according to the age group and the gender. And they were divided into 3 groups(group 1: 1981-1985, group 2: 1985-1990, group 3: 1991-1995) by 5 year interval according to the treated year. The periodontal treatment modalities were classified into non-surgical therapy, pocket elimination surgery, regenerative periodontal surgery, mucoginigival surgery, clinical crown lengthening, and others. The results were as follows; 1.In the distribution of the periodontally treated patients according to the age group, 40's age group was the highest, and 30's, 40's, and 50's age groups occupied more than two thirds(73%). 2.The sexual distribution of the periodontally treated patients showed that males(53.4%) were a little more than females(46.6%). Within 20's group female was higher, but within 40's male was higher. 3.Regardless of the age group and the gender, pocket elimination surgery was the most frequent treatment modality. 4.In group 1 and 2(1981-1990) the main treatment modality was pocket elimination surgery and non-surgical therapy, but in group 3(1991-1995) it was regenerative periodontal surgery and pocket elimination surgery. The above results suggest that the prevention of periodontal disease should be initiated from early twenties, and the most frequent treatment modality may be closely related with development of new material and method.

Clinical Evaluation After Periodontal Flap Surgery with/without Non-Surgical Periodontal Therapy / 대한치주과학회지

In the treatment of chronic adult periodontitis, scaling and root planing have been generally performed prior to periodontal flap surgery. The purpose of this study was to evaluate the clinical significance of non-surgical periodontal therapy prior to periodontal flap surgery in patients with chronic adult periodontitis. Fifty six molars showing bilateral bony defects and 4-6mm periodontal pocket in twelve patients with chronic adult periodontitis were selected. By randomized split-mouth design, in one side, flap operation was performed 4 weeks after scaling and root planing, in the other group, flap operation was only performed without scaling and root planing. Probing pocket depth, gingival recession, clinical attachment level, gingival index, plaque index, and tooth mobility were measured at baseline, before flap operation and post-operation 12 weeks. The difference of clinical parameters between groups and between each measuring time was statistically analyzed. The results were as follows; 1. At 12 weeks after flap operation, there was no significant difference in probing pocket depth, gingival recession, clinical attachment level, gingival index, plaque index and tooth mobility between groups(p<0.05). 2. In both groups, probing pocket depth, gingival recession, clinical attachment level, gingival index, plaque index and tooth mobility were significantly improved at 12 weeks after flap operation compared to baseline(p<0.05). Within the limitation of short period, the results failed to demonstrate that the non-surgical periodontal therapy prior to periodontal flap surgery could have clinical significance in improvement of clinical parameters compared to periodontal surgery without non-surgical periodontal therapy.

Immunohistochemical Study of the Expression of Bone Morphogenetic Protein(BMP-7) Following Regenerative Periodontal Surgery / 대한치주과학회지

Extracellular matrix component is degraded by enzymes of thematrix metalloproteinases(MMPs). MMPs are produced by both hemopoietic and structural cells. Increased activity of MMP-3 in periodontium is strongly associated with inflammatory periodontal disease. The purpose of the present study was to estimate the effect of BMP-7 on regeneration of periodontium. The optical density was measured by microwell plate reader at 450 nm.The difference of the optical density and the relative activity ofMMP-3 according to the concentration were statistically analyzed by one way ANOVA. The results were as follows: 1.Tetracycline-HCl showed the tendency to inhibit the activity of MMP-3 at the concentration lower than 25microgram/ml. 2.Doxycycline-HCl inhibited significantly the activity of MMP-3 at the concentration lower than 100microgram/ml. 3.Minocycline-HCl inhibited the activity of MMP-3 at the concentration in the range of 10 to 200microgram/ml. Within the limit of the present study, the above results suggested that bone morphogenetic protein-7 may play a important role in development of periodontium.

Evaluation of Statistical Analysis of Articles in Journal of Korean Academy of Periodontology / 대한치주과학회지

The purpose of this study was to analyze the statistical errors of articles in the Journal of Korean Academy of Periodontology from 1973 to 1999. Of the 662 articles examined, 263 were included which analyzed the data. They were classified into 2 groups with time lapse; group 1: 1973~1989, group 2: 1990~1999. Authors made checklists for analyzing the data and detecting the errors and analyzed them with professional statistician. The results were as follows: 1. Of 263 atricles which applied statistical method, 40(19.3%) was in group 1, 223(49.0%) in group2. 2. In the number of statistical method applied, 170(64.6%) were analyzed with 1 statistical method, 73(27.8%) with 2 methods, 18(6.8%) with 3 methods, and 2(0.8%) with 4 methods 3. The number of statistical methods applied was 14, and they were applied in order of 119 of ANOVA, 72 of Student t-test, 63 of Paired t-test, 36 of CORRELATION, and 21 of Mann-Whitney U test. 4. In 87(33.1%) of 263 articles and in 18 error items, statistical errors were found out. In group I, 9 items (55%) of error were found out, and were in order of 5 of Student t-test instead of Paired t-test, and 4 of unnecessary statistical analysis. In group II, 16 items (29.1%) of error were found out, and were in order of 22 of Student t-test instead of Paired t-test, 7 of no multiple comparison test after ANOVA, 6 of Student t-test instead of ANOVA, 6 of unnecessary statistical analysis, and 5 of ANOVA instead of Paired t-test. In conclusion, the results noted that statistical analyses were increased, but statistical errors were decreased with time. But authors suggest that researchers should refer to standard statistical texts and seek advice from professional statisticians to avoid the statistical errors.

The Inhibitory Effect of Metronidazole and Doxycycline-HCl on proMMP-3 Production in Gingival Fibroblast / 대한치주과학회지

No abstract available.

Effect of Smoking on Gingival Blood Flow / 대한치주과학회지

Recent studies have demonstrated that smoking may be one of the most significant risk factors in the development and progression of periodontal disease. Reports have indicated that smoking causes gingival blood flow to be decreased. However, studies on the effects of smoking on gingival blood flow have yielded contradictory results. The purpose of the present study was to determine the effect of smoking on gingival blood flow. One hundred volunteers(fifty non-smokers and fifty smokers) with good general and periodontal health, aged twenties(non-smoker : 22-29 years, mean=25.36, smoker : 23-29 years, mean=26.64) were selected. Laser Doppler flowmetry (floLAB, Moor Instruments Ltd., England) was applied to measure the gingival blood flow of interdental papilla, marginal gingiva, attached gingiva and alveolar mucosa of left and right upper lateral incisors. In smokers, following an overnight abstinence from smoking, gingival blood flow was measured before smoking, immediately after smoking, 1-, 2-, 3-, 4-, 5- and 6-hour after smoking from 9 a.m. to 3:30 p.m. The difference of blood flow in each tissue of non-smokers and that of each measuring time and each tissue of smokers were statistically analyzed by one way ANOVA and Tukey test. And the difference of blood flow between smokers and non-smokers in each tissue was statistically analyzed by t-test. The results were as follows : 1. Mean blood flow was highest in alveolar mucosa, followed by interdental papilla, attached gingiva and marginal gingiva in both smokers and non-smokers. There was a statistically significant difference in each tissue(p<0.05). 2. There was no consistent result between mean blood flow before smoking in smokers and that of nonsmokers in each tissue. 3. There was a statistically significant difference between gingival blood flow at measuring time point and gingival blood flow of smokers in each tissue(p<0.05). The present study suggested that smoking could alter the gingival blood flow, thus might be partly contributed to periodontal destruction.

Effect of Smoking on Gingival Blood Flow / 대한치주과학회지

Recent studies have demonstrated that smoking may be one of the most significant risk factors in the development and progression of periodontal disease. Reports have indicated that smoking causes gingival blood flow to be decreased. However, studies on the effects of smoking on gingival blood flow have yielded contradictory results. The purpose of the present study was to determine the effect of smoking on gingival blood flow. One hundred volunteers(fifty non-smokers and fifty smokers) with good general and periodontal health, aged twenties(non-smoker : 22-29 years, mean=25.36, smoker : 23-29 years, mean=26.64) were selected. Laser Doppler flowmetry (floLAB, Moor Instruments Ltd., England) was applied to measure the gingival blood flow of interdental papilla, marginal gingiva, attached gingiva and alveolar mucosa of left and right upper lateral incisors. In smokers, following an overnight abstinence from smoking, gingival blood flow was measured before smoking, immediately after smoking, 1-, 2-, 3-, 4-, 5- and 6-hour after smoking from 9 a.m. to 3:30 p.m. The difference of blood flow in each tissue of non-smokers and that of each measuring time and each tissue of smokers were statistically analyzed by one way ANOVA and Tukey test. And the difference of blood flow between smokers and non-smokers in each tissue was statistically analyzed by t-test. The results were as follows : 1. Mean blood flow was highest in alveolar mucosa, followed by interdental papilla, attached gingiva and marginal gingiva in both smokers and non-smokers. There was a statistically significant difference in each tissue(p<0.05). 2. There was no consistent result between mean blood flow before smoking in smokers and that of nonsmokers in each tissue. 3. There was a statistically significant difference between gingival blood flow at measuring time point and gingival blood flow of smokers in each tissue(p<0.05). The present study suggested that smoking could alter the gingival blood flow, thus might be partly contributed to periodontal destruction.

Healing of the Bone around Hydroxyapatite-Coated Implants without Primary Bone Contact / 대한치주과학회지

Implant stability is the key to long-term successful outcome for osseointegrated implants. To evaluate the initial healing response of bone around HA-coated implants without primary bone contact. 21 HA-coated thread type implants(STERI-OSS?) were placed in the femurs of 5 mongrel dogs, about 1-year old. Implants, 8 mm in length and 3.8mm(experimental 1group), 5.0mm(experimental 2group) and 6.0mm(control group) in diameter, were inserted after 3 holes of 6.0mm in diameter and 10mm in depth were prepared in the surgical sites each dog. Implants were supported by only non-resorbable membrane(Teflon(R)), in order to prevent the ingrowth of upper soft tissue into the gap between bone and implant, and to maintain each implant to be positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 implants were inserted in 2 dogs for mobility test and removal torque test. Fluorescent dyes were injected for the observation of new bone formation in order of Terramycin(R), Arizarin Red(R), and Calcein(R) at an interval of 2 weeks. 3 dogs were sacrificed for histologic observation at 4, 8, and 12-week after placement. Light microscopy and confocal laser scanning microscopy were used to qualitatively characterize the bone around HA-coated implant. 2 dogs were sacrificed for mobility test(Periotest(R), Simens AG, Bensheim, Germany) and removal torque test (Autograph(R) AGS-1000D series, Japan) at 8 and 12-week after placement The results were as follows: 1. Histologic observation showed that osseointegration occurred to both control and experimental groups as time lapse, but delayed bone healing was revealed in 3.8mm group (experimental 1group), compared to contrtol group and 5.0mm group (experimental 2group). 2. The mobility test showed that the experimental groups had no distinguishable movement during experimental periods of 8 and 12-week, and there was no difference in mobility depending on the gap between bone and implant, and time lapse. 3. The removal torque forces were increased depended on the gaps decreasing between bone and implant, and time lapse. The results suggest that HA-coated implant without primary bone contact, based on guided bone regeneration could obtain its stability in all experimental groups as time lapse, but bone healing was delayed in experimental group of 3.8mm. And the results suggested that studies on correlationship between mobility test and removal torque test for implant stability would be necessary.

Surface characteristics and biocompatibility of bioinert nitrides ion plated titanium implant / 대한치주과학회지

Even though titanium(Ti) and its alloys are the most used dental implant materials, there are some problems that Ti wears easily and interferes normal osteogenesis due to the metal ions. Ti coated with bioactive ceramics such as hydroxyapatite has also such problems as the exfoliation or resorption of the coated layer. Recent studies on implant materials have been proceeding to improve physical properties of the implant substrate and bio Compatibility of the implant surfaces. The purpose of the present study was to examine the physical property and bone tissue compatibility of bioinert nitrides ion plated Ti. Button type specimens(l4mm in diameter, 2.32mm in height) for the abrasion test and cytotoxicity test and thread type implants(3.75mm in diameter, 6mm in length) for the animal experiments were made from Ti(grade 2) and 316LVM stainless steel. Ti specimens were ion plated with TiN, ZrN by the low temperature arc vapor deposition, and the depth profile of the TiN/Ti, ZrN/Ti ion plated surface was examined by Auger Electron Spectroscopy. Three kind of button type specimens of TiN/Ti, ZrN/Ti and Ti were used for abrasion test, and HEPAlClC7 cells and CCD cells were cultivated for 4 days with the specimens for cytotoxicity test. Thread type implants of TiN, ZrN/Ti, Ti, 316LVM were implanted on the femur of 6 adult dogs weighing l0kg-l3kg. Two dogs were sacrified for histological examination after 45 days and 90 days, and four dogs were sacrificed for the removal torque test of the implants after 90 days. The removal torque force was measured by Autograph (Shimadzu Co., AGS-l000D series, Japan). Abrasion resistance of TiN/Ti was the highest, and that of ZrN/Ti and Ti were Followed. The bioinert nitride ion plated Ti had much better abrasion resistance, compared with Ti. In the cytotoxicity test, the number of both cells were increased in all specimens, and there were no significant difference in cytotoxic reaction among all groups (p>0.1). In histological examination, 316LVM showed the soft tissue engagement in interface between the implant and bone, but the other materials after 45 day5 noted immature new bone formation in the medullary portion along the implant surface, and those after 90 days showed implant support by new bone formation in both the cortical and the medullary portion. The removal torque force of TiN/Ti showed significantly higher than that of Ti(p0.05), and that of 316LVM was lowest among all groups(p<0.05). These results suggest that bioinert nitrides ion plated Ti can resolve the existing problems of Ti and bioactive ceramics, and it may be clinically applicable to human.

Healing of the bone around pure titanium implants without primary bone contact / 대한치주과학회지

Primary fixation is one of the most important factor in establishing adequate osseointegration between implant and bone. To evaluate the initial healing response of bone around implants without primary bone contact, this study was designed to create considerable space between implant and bone in 5 mongrel dogs, about l-year old. After 3 holes of 6 . h in diameter were prepared at the femur neck of the dogs, commercially pure titanium thread type implants(STERI-OSS

Effect of Tetracycline Analogues on The Activity of Matrix Metalloproteinase-3 in Gingival Fibroblasts / 대한치주과학회지

Extracellular matrix component is degraded by enzymes of thematrix metalloproteinases(MMPs). MMPs are produced by both hemopoietic and structural cells. Increased activity of MMP-3 in periodontium is strongly associated with inflammatory periodontal disease. The purpose of the present study was to determine the effect of tetracycline analogues on the activity of MMP-3. Tetracycline-HCl, doxycycline-HCl, and minocycline-HCl were applied to huamn gingival fibroblasts at various concentrations of 10, 25, 50, 100, 200microgram/ml, and 1 hour later IL-1beta of 25ng/ml was added. After incubation for 24 hours the cells were reacted by enzyme-linked immunosorbent assay using proMMP-3 ELISA kit. The optical density was measured by microwell plate reader at 450nm. The relative activity of MMP-3 was calculated as the percentage of the optical density of each experimental group to that of the control. The difference of the optical density and the relative activity of MMP-3 between the experimental groups and the control wasstatistically analyzed by one way ANOVA. The results were as follows: 1. Tetracycline-HCl showed the tendency to inhibit the activity of MMP-3 at the concentration lower than 25 microgram/ml, but increased significantly the activity of MMP-3 at the concentration of 200microgram/ml(p<0.05). 2. Doxycycline-HCl inhibited significantly the activity of MMP-3 at the concentration lower than 100microgram/ml, but increased significantly the activity of MMP-3 at the concentration of 200microgram/ml(p<0.05). 3. Minocycline-HCl inhibited the activity of MMP-3 at the concentration in the range of 10 to 200microgram/ml. Within the limit of the present study, the above results suggested that the low concentration of tetracycline analogues could inhibit the activity of MMP-3 induced by IL-1beta in human gingival fibroblasts.

Effect of Tetracycline-HCl on superoxide anion generation by polymorphonuclear leukocytes / 대한치주과학회지

It has been believed that the increased release of free oxygen radicals(O2-, H2O2 and OH-) might be one of important factors in the pathogenesis of periodontal diseases. Polymorphonuclear leukocytes(PMNs) constitute the primary host resistance factor against infection. They are prominent cells in both the gingival tissue and gingival sulcus in most forms of periodontal disease. In response to invading microorganisms, the activated PMNs and macrophages generate free oxygen radicals, which play an important role in bacterial killing. The normal production of these free oxygen radicals is vital for the successful resistance of individuals to bacterial infection. However, the enhanced production of reactive oxygen species by accumulating PMNs may be detrimental to the host in certain disease states. This study was performed to evaluate the effect of Tetracycline-HCl(Tc-HCl) on generation of superoxide anion by PMNs. For the present study, 60ml of peripheral venous blood were obtained from systemically healthy subjects by venipuncture in median cubital vein and PMNs were separated by a one-step Ficoll-Hypaque gradient centrifugation method. PMNs were incubated with 1microgram/ml P.gingivalis strain A7436 LPS, 5% serum and Tc-HCl(5, 10, 50 and 100microgram/ml). The superoxide anion analysis was carried out by superoxide dismutase-inhibitable cytochrome C reduction method using Microplate autoreader(BIO-TEK(TM) Instrument Inc.). The difference of superoxide anion generation between control group and Tc-HCl group was statistically analyzed by paired t-test. The superoxide anion generation in the course of time after treatment with Tc-HCl was analyzed by ANOVA, and the superoxide anion generation in the course of time after treatment with various concentrations of Tc-HCl was analyzed by Repeated Measurement test. The results were as follows: 1. Superoxide anion generation by PMNs was significantly decreased by Tc-HCl(p0.05). 3. Superoxide anion generation by PMNs was significantly decreased in the course of incubation time after treatment with Tc-HCl(p<0.05). The results demonstrate that the Tc-HCl inhibit superoxide anion generation by PMNs and the inhibitory effects depend on the exposure time rather than the concentration of Tc-HCl.

Effect of different application modalities of EDTA on dentinal tubule opening: a SEM study / 대한치주과학회지

Root conditioning has been introduced to dissolve the smear layer, and to aid in detoxification following root planing. It produces surface demineralization, resulting to exposure of dentin collagen fibrils and opening of dentinal tubules. The purpose of the present study was to examine the possibility of obtaining root conditioning effect by using ethylenediamine tetraacetic acid(EDTA) solution instead of low pH etchants such as citric acid and tetracycline hydrochloride(Tc-HCl). Total 48 root specimens(4x5x2mm) were prepared from the mesial and distal root of 24 periodontitisaffected human mandibular molars after scaling and root planing. The specimens were treated with EDTA(17%, neutral pH, Pulpdent?, Pulpdent Co., USA) for 1 min., 2 min., and 3 min., and tetracycline hydrochloride(100mg/ml) for 5 min. using the rubbing technique and the placement technique without rubbing. The dentinal tubules of the specimens were examined under a scanning electron microscopy(JEOL, JSM- 840A, Japan). On the microphotographs taken at x3,000 magnification, the number of identifiable dentinal tubules, opened dentinal tubules, and fully opened dentinal tubules(over 0.9micrometer in diameter) per the unit area(1,067?m2) were counted. And the rate of opened dentinal tubule and the rate of fully opened dentinal tubule were calculated. The difference of those rates among all groups was statistically analyzed by ANOVA and Dunkan test. The results were as follows; 1. In the specimens applied with EDTA, the rate of opened dentinal tubule was not significantly different between each group regardless of application technique and application time(p>0.1). 2. In the specimens applied with EDTA, the rate of fully opened dentinal tubule had tendency to be increased in proportion to application time regardless of application technique. 3. In the specimens applied with EDTA within 2 min., the rate of fully opened dentinal tubule failed to show significant difference between the two techniques(p>0.1). But, in the specimens applied for 3 min., the rate of fully opened dentinal tubule was significantly higher in the specimens applied by the rubbing technique than those by the placement technique(p0.1). The results demonstrate that 17% EDTA solution can replace low pH etchants for root conditioning, and the rubbing technique for at least 3 min. is recommendable.

Orthodontic treatment using indirect bonding technique in periodontitis / 대한치주과학회지

Periodontal disease and/or loss of teeth brings pathologic tooth migration that can result in esthetic and occlusal problems. Diastema and general spacing of the teeth, particularly in the anterior segments of the dentition are frequently developed in individuals with advanced periodontal disease. Thus, the overall treatment plan for a patient with advanced periodontal disease often involves periodontal orthodontic combined therapy. Orthodontic treatment in adults with periodontal disease is restricted to tooth alignment with special caution. Indirect bonding can achieve accurate bracket placement. A 38 year old woman with adult periodontitis was treated by periodontal therapy. Subsequently, her diastema was orthodontically corrected by indirect bonding technique. It must be an appropriate case report of periodontal-orthodontic combined therapy.

A study of gingival blood flow using laser Doppler flowmetry / 대한치주과학회지

The periodontal health has been evaluated clinically by various epidemiological indices, and in researches by measurement of gingival crevicular fluid. Laser Doppler flowmetry is a reliable and objective method that allows immediate measurement of erythrocyte flux in approximately one cubic mm of the capillary bed without disturbing the tissues. The purpose of the present study was to determine whether human gingival blood flow was different according to measuring area, measuring time, and sex or not. Forty volunteers with good general and periodontal health, aged early twenties and unmarried, were selected. Laser Doppler flowmetry(floLAB(R), Moor Instruments Ltd., England) was applied to measure the gingival blood flow of marginal gingiva, interdental papilla, attached gingiva and alveolar mucosa. The blood flow of interdental papilla was measured at 9-10 AM, 1-2 PM, and 5-6 PM. The difference of blood flow according to measuring area and measuring time was statistically analyzed by one way ANOVA and Dunkan test, and the difference of blood flow between men and women was statistically analyzed by t-test. (1) Mean blood flow was significantly higher in alveolar mucosa than in the gingiva(p0.1). (2) Mean blood flow was significantly higher at 5-6 PM than at 9-10 AM and 1-2 PM(p0.1). (3) There was no significant difference in gingival blood flow between men and women(p>0.1). The above results suggest that the measurment of gingival blood flow using laser Doppler flowmetry may be clinically applicable to early determination of gingival inflammation and evaluation of healing status, but further studies are necessary to standardize and simplify the measuring procedure.

The effect of a pulsed-Nd:YAG laser irradiation on microstructure of human gingiva / 대한치주과학회지

Since laser therapy has been applied to dentistry, many dental practitioners are very interested in laser therapy on various intraoral soft tissue lesions including gingival hyperplasia and aphthous ulcer. The purpose of the present study was to determine the therapeutic effect and the harmful effect of a pulsed-Nd:YAG laser irradiation on human gingival tissue. In twenty periodontal patients with gingival enlargement, the facial gingival surface of maxillary anterior teeth was randomly irradiated at various power of 1.0W(100mJ, 10Hz), 3.0W(100mJ, 30Hz) and 6.0W(150mJ, 40Hz) for 60 seconds by contact delivery of a pulsed-Nd:Y AG laser(EN.EL.EN060, Italy). Immediately after laser irradiation, the gingival tissues were surgically excised and prepared in size of 1mm3. Subsequently the specimens were processed for prefixation and postfixation, embedded with epon mixture, sectioned in 1micron thickness, stained with uranyl acetate and lead citrate, and observed under transmission electron microscope(JEM 100 CXII). Following findings were observed; 1. In the gingival specimens irradiated with 1.0W power, widening of intercelluar space and minute vesicle formation along the widened intercellular space were noted at the epithelial cells adjacent to irradiated area. 2. In the gingival specimens irradiated with 3.0W power, the disruption of cellular membrane, aggregation of cytoplasm, and loss of intercellular space were observed at the epithelial cells adjacent to irradiated area. 3. In the gingival specimens irradiated with 6.0W power, the disruption of nuclear and cellular membrane was observed at the epithelial cells adjacent to irradiated area. The ultrastructural findings of this study suggest that surgical application of a pulsed-Nd:YAG laser on human gingival tissue may lead somewhat delayed wound healing due to damage of epithelial cells adjacent to irradiated area.

Evaluation of cytotoxicity and bone affinity on the surface of a titanium phosphide / 대한치주과학회지

Dental implants have been developed for enhancement of osseointegration. Biocompatibility, bone affinity and surface characteristics of dental implants are very important factors for osseointegration. The aim of the present study was to determine the cytotoxicity and the bone affinity of titanium phosphide(Ti-P) implant material. The Ti-P surface was obtained by vacuum sintering of titanium within compacted hydroxyapatite powder. The composition and the chemical change of the surface were determined by Auger electron spectroscopy. The in vitro cytotoxicity was evaluated by the viability of the bone cells and macrophages obtained from chicken embryo and rat,s peritonium, respectively. For the comparative evaluation, 316L stainless steel, commercially pure titanium and Ti-P materials, prepared in size of 10.0mm in diameter and 5.0mm in height, were immersed separately in bone cells and macrophages for 10 days. For the evaluation of the in vivo bone affinity, 316L stainless steel, commercially pure titanium and Ti-P materials, prepared in size of 5.0mm in diameter and 10.0mm in length, were implanted after drilling in diameter 5.5mm in femurs of 2 dogs weighing 10Kg more or less. Six weeks after implantation the specimens were prepared for histopathological examination and were observed under light microscope. In comparison of in vitro bone cell viability, Ti-P and commercially pure titanium groups were not significantly different from control group(p>0.1), but 316L stainless steel group was significantly lower than control group(p0.1). In comparison of in vivo study, 316L stainless steel and commercially pure titanium showed fibrous encapsulation, but Ti-P showed remarkable new bone formation without any fibrous tissue. The results demonstrate that Ti-P has favorable biocompatibility and bone affinity, and suggest that dental implants with Ti-P surface may enhance osseointegration.

Effect of NaF iontophoresis and Nd:YAG laser irradiation on the abrasion-resistance of root surface / 대한치주과학회지

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 0.05). 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.