• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.137-149
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• 2007

Objective: The purpose of this study was to compare changes in frictional resistance between the bracket and wire under dry and wet conditions according to a change in moment. Methods: A stainless steel bracket of $0.022"{\times}0.028"$ slot, and $0.019"{\times}0.025"$ stainless steel, beta-titanium, and nickel-titanium wires were used. A 10 mm length lever was attached to the test (sliding) brackets to generate a moment. The experimental model was designed to allow tipping until contacts were established between the wire and the mesiodistal edges of the bracket slot. The moment was generated by suspending a 100 g or 200 g weight on the end of the lever. The moments applied were $1000g{\cdot}mm\;(100g{\times}10mm)\;and\;2000g{\cdot}mm\;(200g{\times}10mm)$. The test brackets were ligated with elastomeric ligature for a constant ligation force and the fixed brackets were ligated with stainless steel ligature. Brackets were moved along the wire by means of an universal testing machine, and maximum frictional resistances were recorded. Results: Stainless steel wire showed least frictional resistance and there was no significant difference between beta-titanium and nickel-titanium except at $2000g{\cdot}mm$ moment in wet conditions. Frictional resistance of all wires increased as the moment increased from $1000g{\cdot}mm\;to\;2000g{\cdot}mm$. Under wet conditions, the frictional resistance of stainless steel wires increased in both $1000g{\cdot}mm\;and\;2000g{\cdot}mm$ moment conditions, but frictional resistance of nickel-titanium and beta-titanium increased only in $2000g{\cdot}mm$ conditions. Conclusion: These results indicated that various conditions influence on frictional resistance. Therefore, laboratory studies of frictional resistance should simulate clinical situation.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.295-300
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• 2015

Odontoclasts and osteoclasts resorb tooth root and alveolar bone, respectively. Many studies have focused on osteoclast formation in periodontitis, but effect of periodontitis on odontoclast formation is not clearly clarified. In this study, we observed formation of odontoclasts as well as osteoclasts in rats with ligature-induced periodontitis. To induce periodontitis, ligatures were placed around the first molars in left mandibles of rats. Rats were sacrificed at days 1, 3, and 10 after ligation. After tartrate resistant acid phosphatase (TRAP) staining in mandible section, the number of TRAP-positive odontoclasts and osteoclasts were histologically counted along the root and the alveolar bone surfaces of tooth, respectively. Odontoclasts increased until day 10 in mesial and furcation root surface, but did not increase in distal root surface. When compared odontoclast formation to osteoclast formation in mesial surface, osteoclasts peaked at day 3, and then decreased gradually, whereas odontoclasts were continuously increased until day 10. The number of odontoclasts was lower than that of osteoclasts before and after periodontitis induction. These indicate that periodontitis increased formation of odontoclasts as well as osteoclasts, but odontoclast formation occurs slower and weaker than that of osteoclasts.

• Journal of Society of Preventive Korean Medicine
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• v.18 no.1
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• pp.125-138
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• 2014

Objective : Polycan, exopolymers purified from Aureobasidium pullulans SM-2001 and calcium gluconate have been showed favorable inhibitory effects on the periodontitis and related alveolar bone losses through antioxidant and anti-inflammatory activities, respectively. In the present study, we intended to observe the possible synergic effects of mixed formula consisted of Polycan and calcium gluconate on ligation-induced experimental periodontitis and related alveolar bone losses in rats, and to select the fittest compositions for further developing as effective agents to ameliorate periodontal diseases. Method : Experiments were conducted as two separated two tests - first is synergic effects of Polycan and calcium gluconate 1:1, 1:9 and 9:1 mixtures, and second is 1:99, 2:98, 4:96, 8:92 and 1:9 mixtures. Experimental periodontal diseases were induced by ligature placed around the cervix of upper left incisior teeth of rats. One day after ligation placements, 200mg/kg of each single or mixed formulas of Polycan or/and calcium gluconate were orally administered for 10 days. The changes on the alveolar bone loss index and maxillary bone mineral density (BMD) were observed for detecting alveolar bone losses, and for anti-inflammatory effects, myeloperoxidase (MPO) activities and proinflammatory cytokine (tumor necrosis factor; TNF-${\alpha}$) contents were also evaluated in gingival tissues around ligature placed incisior teeth. The results of mixtures were compared with those of singe Polycan and calcium gluconate treated rat. Results : Each single or mixed formulas of Polycan or/and calcium gluconate favorably and significantly inhibited the inflammatory changes. The inhibitory effects of mixed formula consisted of Polycan and calcium gluconate 1:9 showed against periodontitis and related alveolar bone losses as compared with those of each Polycan and calcium gluconate single formula (p<0.05). In second experiment, Polycan and calcium gluconate 2:98, 4:96, 8:92 and 1:9 mixed formulas also showed significant increased anti-inflammatory and inhibitory effects against alveolar bone losses as compared with those of each single formula. Among them, Polycan and calcium gluconate 2:98 showed the highest efficacy against to ligation-induced experimental periodontitis and related alveolar bone losses. Conclusion : The results obtained in this study suggest that appropriated mixtures of Polycan and calcium gluconate showed synergic inhibitory effects against ligation-induced experimental periodontitis and related alveolar bone losses in rats. Moreover, Polycan and calcium gluconate 2:98 showed the highest efficacies in this experiment, suggesting the fittest composition for further developing as effective agents to ameliorate periodontal diseases.

• Journal of Periodontal and Implant Science
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• v.51 no.6
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• pp.374-385
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• 2021

Purpose: The aim of this study was to evaluate the effects of locally delivered 1% alendronate (ALN) gel used as an adjunct to non-invasive periodontal therapy. Methods: Ligature-induced periodontitis was performed in 96 rats. The ligature was tied in the cervical area of the mandibular left first molar. The animals were randomly divided into 4 groups: 1) NT, no treatment; 2) SRP, scaling and root planning; 3) SRP/PLA, SRP followed by filling the periodontal pocket with placebo gel (PLA); and 4) SRP/ALN, SRP followed by filling the periodontal pockets with 1% ALN gel. Histomorphometric (percentage of bone in the furcation region [PBF]) and immunohistochemical (receptor activator of nuclear factor-κB ligand, osteoprotegerin, and tartrate-resistant acid phosphatase) analyses were performed. Data were statistically analyzed, with the threshold of statistical significance set at P≤0.05. Results: The SRP, SRP/PLA, and SRP/ALN groups presented a higher PBF than the NT group (P≤0.01) at 7, 15, and 30 days. The SRP/ALN group presented a higher PBF than the SRP/PLA group in all experimental periods, as well as a higher PBF than the SRP group at 15 and 30 days. No differences were observed in the immunohistochemical analyses (P>0.05 for all). Conclusions: Locally delivered 1% ALN gel used as an adjunct to SRP enhanced bone regeneration in the furcation region in a rat model of experimental periodontitis.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.389-394
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• 2002

Present study was carried out for development of a new supplementary product with gastroprotective effect. Natural Products mentioned that have GI protective property in Dongeuibogam and reports were evaluated anti-bacterial activity against Helicobacter pylori, then five heres were selected. The material used for the test were water extract of Alpinia oxyphlla (AO), Astragalus membranaceus (AM), Cinnamomum loureirii(CL), Citrus aurantium(CA), Amomum villosum(AV). They were tested individually on HCI ethanol-induced gastric lesion in rats, AV CL, AO showed the most significant effectiveness, respectively. Then two mixture different in their content ratio (P020701-1,-2) and complex with P020701-1 (CP) were made, and tested on HCI·ethanol, indomethacin-induced gastric lesion, aspirin-ligature, Shay ulcer and gastric secretion. P020701-1, -2 and CP showed significant effect on HCI ethanol, indomethacin-induced gastric lesion, and Shay ulcer. It can be regarded that the antigasuitic and anti-ulcerative effects of P020701- 1, -2 and CP are originated from reduction of total acid output identified by gastric secretion test.

• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.283-294
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• 1993

The friction of orthodontic appliances is recogonized to be detrimental to tooth movement. The purpose of this study was to determine the magnitude of frictional force changes between bracket$(018'\times025'\;solt)$ and orthodontic wires(stainless steel, cobalt-chromium, and $\beta-titanium$, $017'\times0.25'$ rectangular) with time. The wire was secured in the bracket slot with a elastomeric ligature. Frictional forces were measured by universal testing machine. The following conclusions were obtained. 1. The frictional forces under dry condition were greater than those in saliva. 2. The frictional forces produced by cobalt-chromium wire were less than those generated by stainless steel and $\beta-titanium$ wire. 3. The frictional forces increased progressively with time, and the amount of increase on first two weeks was greater than on last two weeks. 4. The change of frictional force under dry condition was greater than in artificial saliva.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.343-347
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• 2006

The present study was designed to investigate the effects renin-angiotensin-aldosterone system (RAAS), endothelin (ET) and local natriuretic peptide (NP) system for glomerulopathy induced in the experimental bilateral ureteral obstructive rats. Sprague-Dawley male rats ($200{\sim}220g$ body weight) were bilaterally obstructed by ligation of the proximal ureters for 24 hours. Control rats were treated in the same ways, except that no ligature was made. The glomeruli were isolated from cortex by graded sieve methods, and the mRNA expressions of local renin-angiotensin system (RAS), aldosterone synthase (CYP11B2), endothelin-1 (ET-1) and NP system were determined by real-time polymerase chain reaction. Following the bilateral ureteral obstruction, the mRNA expressions of renin, angiotensin converting enzyme 1 as well as ET-1 were increased, while that of angiotensin converting enzyme 2 was not changed. The expressions of CYP11B2 and angiotensin II receptors were not changed. C-type natriuretic peptide (CNP) expression was increased, while its receptors (natriuretic peptide receptor-B) were not changed. We suggest that the upregulation of local RAS and ET playa role in the progressive glomerular injury, and that the enhanced CNP activity also plays a compensatory role in obstructive uropathy in the glomerulus.

• Journal of Trauma and Injury
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• v.34 no.4
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• pp.219-224
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• 2021

The aim of this review is to introduce the progress in trauma surgery made during war. In the 16th century, Paré reintroduced ligature of arteries, which had been introduced by Celsus and Galen, instead of cauterization during amputation. Larrey, a surgeon in Napoleon's military, adapted the "flying artillery" to serve as "flying ambulances" for rapid transport of the wounded. He established rules for the triage of war casualties, treating wounded soldiers according to the seriousness of their injuries and the urgency of medical care. To treat fractures and tuberculosis, Thomas created the "Thomas splint", which was used to stabilize fractured femurs and prevent infection; in World War I (WWI), use of this splint reduced the mortality of compound femur fractures from 87% to less than 8%. During WWI, Cushing systematized the treatment of head injuries, reducing mortality among head injury patients. Gillies repaired facial injuries, and his experiences became the basis of craniofacial and aesthetic surgery. In WWII, McIndoe discovered that immersion in saline promoted burn healing and improved survival rates, and thus began saline baths and early grafting instead of using tannic acid. A high mortality rate in patients with acute renal failure was noted in WWII and the Korean War. In the Korean War, Teschan used the Kolff-Brigham dialyzer. The first use of medevac with helicopters was the evacuation of three British pilot combat casualties by the US Army in Burma during WWII. As a lotus blooms in the mud, military surgeons have contributed to trauma surgery during wartime.

• The korean journal of orthodontics
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• v.22 no.4 s.39
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• pp.823-836
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• 1992

Guiding a tooth along an arch wire results in a counteracting frictional force among arch wires, bracket and ligature. This frictional forces should be eliminated or minimized when orthodontic teeth movement is being planned. The purpose of this study was to evaluate the changes of width, cross-sectional forms and surface morphologies of stainless steel wire and $Elgiloy^{\circledR}$ wire after electropolising. Experimental variables included in this experiment were arch wire materials, current, electrolyte temperature and polishing time. Wire widths were measured by micrometer and cross-sectional forms and surface morphologies were examined with optical microscope and scanning electron microcope. The results were as follows: 1. The mean and standard deviation of widths of stainless steel wire and $Elgiloy^{\circledR}$ wire varying polishing time with condition of $249A/dm^2$ and $20^{\circ}C,\;249A/dm^2$ and, $332A/dm^2$ and $20^{\circ}C$ and $332A/dm^2$ and $250^{\circ}C$ were obtained. 2. With increasing polishing time, the widths of stainless steel wire and $Elgiloy^{\circledR}$ wire became decreased proportionally 3. The changes of widths of stainless steel wire and $Elgiloy^{\circledR}$ wire were statistically insignificant between $20^{\circ}C$ group and $25^{\circ}C$ group, but significant between $249A/dm^2$ group and $332A/dm^2$ group. 4 The cross-sectional forms of wire after electropolishing were not changed in stainless steel wire, and while it were changed to rounded corners in $Elgiloy^{\circledR}$ wire. 5. The surface morphologies of wire after electropolishing were scratch-absent and more smoothened both in stainless steel wire and $Elgiloy^{\circledR}$ wire.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.1
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• pp.43-53
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• 2007

The purpose of this experimental study was to examine the effect of the decontamination of carbon dioxide ($CO_2$) laser in treatment of ligature-induced peri-implantitis in dogs. A total 24 implants with a sandblasted with large-grit and acid-etched (SLA) surface were inserted in six mongrel dogs. After a 3-month healing period, experimental peri-implantitis characterized by a bone loss of about 3mm was established by inducing with wires. And then wires were removed and plaque control was implemented. Surgical treatment involving flap procedure + debridement of implants surface with chlorhexidine and saline (group 1), flap procedure + GBR with absorbable collagen membrane (Bio-Gide) and mineralized bone graft (Bio-Oss) (group 2), and flap procedure + $CO_2$ laser application + GBR (group 3) was performed. The animals were killed 8 weeks and 16 weeks after treatment, respectively. A histomorphometric analysis confirmed statistically considerable new bone formation within the limit of the 5 most coronal threads in group 3 compared with group 1 at 16 weeks (P<0.05). And intragroup analysis showed considerable increase of new bone formation in group 3 at 16 weeks compared with 8 weeks (P<0.05). The present study demonstrates considerable new bone formation after treatment of experimental peri-implantitis with flap procedure, $CO_2$ laser application and GBR.