• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.647-668
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• 1997

6 beagle dogs aged over one and half years and weighed 14 to 16 Kg were utilized in this study, Horizontal furcation defects were induced around 2nd, 3rd, and 4th premolars bilaterally, PDGF-BB in conjunction with EGF and PDGF-BB only were applied in the right and left premolars respectively. 2 animals were sacrificed at 4weeks, 8 weeks, and 12 weeks, after regenerative surgery respectively. Semi-thin sections using glass-knife were stained with toluidine blue for light microscopic study. The results were as follows: 1. At 4 weeks after regenerative surgery, bone formation in the PDGF-BB-applied site was thriving, but bone formation in the PDGF-BB-and-EGF-applied site was depressed. 2. Bony ankylosis was surely shown along the whole exposed root surface applied with PDGF-BB, but it was shown at the root surface near the base of the bone defect where was applied with PDGF-BB in conjunction with EGF. 3. Active bone formation was made from 8 weeks after regenerative surgery in the PDGF-BB- and-EGF-applied site. 4. Bone maturity as well as speed of bone formation in the PDGF-BB-applied site was superior to those in the PDGF-BB-and-EGF-applied site throughout the whole experimental period. Within the above results, PDGF-BB had the strong capability to form the new bone and EGF was not able to prevent the bony ankylosis thoroughly. However, EGF may have the possibility to prevent the bony ankylosis through the suppression of bone formation.

• Journal of Periodontal and Implant Science
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• v.40 no.5
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• pp.220-226
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• 2010

Purpose: This study was performed to evaluate the periodontal wound healing effect of particulate equine bone mineral on canine alveolar bone defects. Methods: Twelve adult male beagle dogs were used as study subjects. The mandibular second and fourth premolars were extracted prior to the experimental surgery, and the extraction sites were allowed to heal for 8 weeks. After periodontal probing, two-walled defects were created at the mesial and distal sides of the mandibular third premolars bilaterally, and the defects were filled with equine particulate bone with collagen membrane or bovine particulate bone with collagen membrane, or collagen membrane alone. The defects without any treatment served as negative controls. After probing depth measurement, animals were sacrificed at 10, 16, and 24 post-surgery weeks for micro-computed tomographic and histomorphometric analysis. Results: The equine particulate bone-inserted group showed significantly decreased values of probing depth and first bone contact compared to the negative control and collagen membrane alone groups at weeks 10, 16, and 24 (P<0.05). There were no significant differences in the new cementum length, newly-formed bone area, or newly-formed bone volume between equine particulate bone- and bovine particulate bone-inserted groups, both of which showed significantly increased values compared to the negative control and collagen membrane alone groups (P<0.05). Conclusions: Equine particulate bone showed significant differences in probing depth, first bone contact, new cementum length, newly formed bone area, and bone volume fraction values when compared to the negative control and collagen membrane alone groups. There were no significant differences between equine and bovine particulate bone substitutes in these parameters; therefore, we can conclude that equine particulate bone is equivalent to bovine bone for periodontal regeneration.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.2
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• pp.361-382
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• 1997

The effect of fluoride pretreatment upon root resorption after delayed replantation was studied in beagle dogs. Upper and lower incisors were extracted and bench dried for 45 minutes. 1% Stannous fluoride solution, 2% neutral sodium fluoride gel and 1.23% acidulated phosphate fluoride gel were used for the pre-treatment of replanted root surface in the experimental groups. Replantation was done with no treatment in control group. After of an experimental periods 3 weeks, animals were sacrificed by perfusion followed by sample preparation. A histomorphometric method was applied for evaluation of tissue reactions observed in each group under light microscope. Scanning electron microscopic observation was done to find out any different surface topography between groups. The results were as follows: 1. Fluoride-treated groups showed in general the better healing patterns than untreated control group. 2. Comparisons between three experimental groups revealed the general superiority of APF-treated group over the other groups in terms of tissue healing reaction by showing the highest frequency in uncomplicated healing pattern and surface resorption and the lowest in inflammatory resorption, but with no statistical significance(p>.05). 3. Scanning elecron micrographs showed the irregular distribution of resorption cavities and the attached bone of variable size and shape in all groups. 4. It can be concluded that the types of fluoride did not have significant impact on the early tissue reactions after delayed replantation under the condition of the present experiment.

• Toxicological Research
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• v.35 no.2
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• pp.119-129
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• 2019

As the use of cosmetics has greatly increased in a daily life, safety issues with cosmetic ingredients have drawn an attention. Drometrizole [2-(2'-hydroxy-5'-methylphenyl)benzotriazole] is categorized as a sunscreen ingredient and is used in cosmetics and non-cosmetics as a UV light absorber. No significant toxicity has been observed in acute oral, inhalation, or dermal toxicity studies. In a 13-week oral toxicity study in beagle dogs, No observed adverse effect level (NOAEL) was determined as 31.75 mg/kg bw/day in males and 34.6 mg/kg bw/day in females, based on increased serum alanine aminotransferase activity. Although drometrizole was negative for skin sensitization in two Magnusson-Kligman maximization tests in guinea pigs, there were two case reports of consumers presenting with allergic contact dermatitis. Drometrizole showed no teratogenicity in reproductive and developmental toxicity studies in which rats and mice were treated for 6 to 15 days of the gestation period. Ames tests showed that drometrizole was not mutagenic. A long-term carcinogenicity study using mice and rats showed no significant carcinogenic effect. A nail product containing 0.03% drometrizole was nonirritating, non-sensitizing and non-photosensitizing in a test with 147 human subjects. For risk assessment, the NOAEL chosen was 31.75 mg/kg bw/day in a 13-week oral toxicity study. Systemic exposure dosages were 0.27228 mg/kg bw/day and 1.90598 mg/kg bw/day for 1% and 7% drometrizole in cosmetics, respectively. Risk characterization studies demonstrated that when cosmetic products contain 1.0% of drometrizole, the margin of safety was greater than 100. Based on the risk assessment data, the MFDS revised the regulatory concentration of drometrizole from 7% to 1% in 2015. Under current regulation, drometrizole is considered to be safe for use in cosmetics. If new toxicological data are obtained in the future, the risk assessment should be carried out to update the appropriate guidelines.

• Journal of Periodontal and Implant Science
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• v.53 no.3
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• pp.207-217
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• 2023

Purpose: Non-crosslinked and crosslinked collagen membranes are known to exhibit distinct degradation characteristics, resulting in contrasting orientations of the adjacent tissues and different biological processes. The aim of this study was to conduct a histomorphometric assessment of non-crosslinked and crosslinked collagen membranes regarding neovascularization, tissue integration, tissue encapsulation, and biodegradation. Methods: Guided bone regeneration was performed using either a non-crosslinked (BG) or a crosslinked collagen membrane (CM) in 15 beagle dogs, which were euthanized at 4, 8, and 16 weeks (n=5 each) for histomorphometric analysis. The samples were assessed regarding neovascularization, tissue integration, encapsulation, the remaining membrane area, and pseudoperiosteum formation. The BG and CM groups were compared at different time periods using nonparametric statistical methods. Results: The remaining membrane area of CM was significantly greater than that of BG at 16 weeks; however, there were no significant differences at 4 and 8 weeks. Conversely, the neovascularization score for CM was significantly less than that for BG at 16 weeks. BG exhibited significantly greater tissue integration and encapsulation scores than CM at all time periods, apart from encapsulation at 16 weeks. Pseudoperiosteum formation was observed in the BG group at 16 weeks. Conclusions: Although BG membranes were more rapidly biodegraded than CM membranes, they were gradually replaced by connective tissue with complete integration and maturation of the surrounding tissues to form dense periosteum-like connective tissue. Further studies need to be performed to validate the barrier effect of the pseudoperiosteum.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.4
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• pp.307-314
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• 2013

Purpose: The aim of this study was to evaluate the effect of immobilization of the recombinant human bone morphogenetic protein 2 (rhBMP-2) on anodized titaum implants coated with heparin to enhance the vertical alveolar ridge augmentation in the supraalveolar peri-implant defect region. Materials and methods: 18 pure titanium implants (7.0 mm in length, 3.5 mm in diameter) were manufactured for this study. All implants were anodized and designed insertion reference line marked with laser at the apical 2.5 mm from the fixture platform. Implantation of 6 noncoated anodized implants (Control group), 6 anodized implants physically adsorbed with rhBMP-2 by dip and dry method (BMP group) and 6 anodized implants chemically immobilized 3,4-dihydroxyphenylalanine (DOPA)-heparin/ rhBMP-2 (Hep-BMP group) was performed in the both mandibular of three male adult beagle dogs using split-mouth design. Radiologic examinations were performed immediately after implant placement and 4 and 8 weeks after implant placement. The amount of mesio-distal bone augmentation was evaluated by measuring the vertical distance from the platform to the marginal bone. Statistical analysis was performed using one-way analysis of variance (SPSS version 18.0) and multiple comparison analysis of The Kruskal-Wallis test and the Mann-Whitney U test. Statistical significance was established at the 5% significant level. Results: At the 4 weeks vertical alveolar ridge augmentation of Control group, BMP group and Hep-BMP group is $0.09{\pm}0.22mm$, $1.02{\pm}0.72mm$, and $1.29{\pm}0.51mm$, At the 8 weeks $0.11{\pm}1.26mm$, $1.11{\pm}0.58mm$, $1.59{\pm}0.79mm$ according to radiographic observations. The two experimental groups showed a significantly increasing in vertical bone height compared with the control group (P<.05). However, there is no significant difference between the BMP group and Hep-BMP group (P>.05). Conclusion: The rhBMP-2 coated implants were enhanced the vertical bone growth in the supraalveolar peri-implant defect area. However, there is no significant difference between chemically and physically coating method.

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.599-613
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• 2003

The goal of periodontal treatment is regeneration of the periodontium. Bone graft and absorbable PLA/PGA membrane have been used for this purpose. In this study, 4${\times}$4mm 1-wall intrabony defects were surgically created bilaterally in the mandible of five male beagles. The control group went through a conventional flap operation, while the experimental group I was treated with absorbable PLA/PGA membranes only, group II was treated with absorbable membrane and calcium phosphate. The results are the following : 1. The defect height was 4.82${\pm}$0.45mm in the control group, 4.93${\pm}$0.79mm in the experimental I group, and 4.92${\pm}$0.62mm in the experimental II group. There was no statistically significant difference among 3 groups(P <0.05). 2. The amount of junctional epithelium migration was 30.90${\pm}$9.92% of the defect height in the control group, 39.16${\pm}$7.51% in the experimental I group, and 38.68${\pm}$12.22% in the experimental II group. There was no statistically significant difference among 3 groups(P <0.05). 3. The amount of connective tissue adhesion was 36.38${\pm}$9.03% in the control group, 14.73${\pm}$3.93% in experimental I group, and 27.87${\pm}$9.70% experimental II group. Experimental group I was a statistically significantly different from control group(P <0.05). 4. The amount of new cementum regeneration was 32.92${\pm}$10.51%, 50.04${\pm}$7.61%, and 39.62${\pm}$12.14% for the control, experimental I, and experimental II group respectively. Experimental group I was a statistically significantly different from control group(P<0.05). 5. The amount of new alveolar bone regeneration was 27.24${\pm}$7.49%, 40.75${\pm}$8.03%, and 36.47${\pm}$15.11% for the control, experimental I, and experimental II group respectively. Experimental group I was a statistically significantly different from control group(P <0.05). The results suggest that the use of PLA/PGA membrane in 1-wall intrabony defect of beagle dogs may promote periodontal regeneration. Further studies are required to determine their regeneration effects.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.337-349
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• 2008

Despite an improved bone reactions of Mg-incorporated implants in the animals, little yet has been carried out by the experimental investigations in functional loading conditions. This study investigated the clinical and histologic parameters of osseointegrated Mg-incorporated implants in delayed loading conditions. A total of 36 solid screw implants (diameter 3.75 mm, length 10mm) were placed in the mandibles of 6 beagle dogs. Test groups included 18 Mg-incorporated implants. Turned titanium Implants served as control. Gold crowns were inserted 3 months. Radiographic assessments and stabilitytests were performed at the time of fixture installation, $2^{nd}$ stage surgery, 1 and 3 months after loading. Histological observations and morphometrical measurements were also performed. Of 36 implants, 32 displayed no discernible mobility, corresponding to successful clinical function. There was no statistically significant difference between test implants and controls in marginal bone levels (p=0.413) and RFA values. The mean BIC % in the Mg-implants was $54.4{\pm}20.2%$. The mean BIC % in the turned implant was $48.9{\pm}8.0%$. These differences between the Mg-implant and control implant were not statistically significant (P=0.264). In the limitation of this study, bone-to-implant contact (BIC) and bone area of Mg-incorporated oxidized implant were similar to machine-turned implant. The stability analysis showed no significantly different ISQ values and marginal bone loss between two groups. Considering time-dependent bone responses of Mg-implant, it seems that Mg-implants enhanced bone responses in early loading conditions and osseointegrated similarly to cp Ti implants in delayed loading conditions. However, further investigations are necessary to obtain long-term bone response of the Mg-implant in human.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.491-498
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• 2015

We investigated the effect of constant rate infusion (CRI) with doxapram on cardiopulmonary function during total intravenous anesthesia (TIVA) with remifentanil and propofol CRI in dogs. Fifteen male Beagle dogs were randomly divided into 3 groups. All groups were premedicated with medetomidine ($20{\mu}g/kg$, IV) and anesthetized by remifentanil/propofol CRI for one and half hour. At the initiating of the anesthesia, different doses of doxapram for each group were administrated as the followings; D1 group - doxapram 0.25 mg/kg bolus followed by doxapram $8.33{\mu}g/kg/min$, D2 group - doxapram 2 mg/kg bolus followed by doxapram $66.66{\mu}g/kg/min$, control group - normal saline. The anesthetic depth for surgery was well maintained in all groups throughout the anesthetic periods. The respiratory rate was significantly higher in D2 group than that of control group (p < 0.05). The values of $PaO_2$ and $SaO_2$ were significantly increased in both D1 and D2 groups compared with control group (p < 0.05). High dose of doxapram (D2 group) significantly decreased the level of $PaCO_2$ compared with control group (p < 0.05). The values of systolic, mean and diastolic arterial pressure were significantly increased in doxapram 2 group (p < 0.05). There were no significant differences in the values of heart rate and pH of arterial blood. Therefore, doxapram CRI may be useful to alleviate the suppression of cardiopulmonary function including hypoxia and hypotension during TIVA with remifentanil and propofol in dogs.

• The korean journal of orthodontics
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• v.33 no.2 s.97
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• pp.91-102
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• 2003

This study was performed to investigate the effect of immediate orthodontic force on soft md hard tissues surrounding C-Palatal $Plate^{TM}$ in beagle Dog. Immediately after this appliance was implanted on the midpalate of 4 adult beagle Dogs, 400gm continuous orthodontic force was applied. Experimental animals were euthanized at 8weeks, 18weeks, and 22weeks (including post-removal healing time of 4weeks), and a control animal was euthanized at 8weeks after implantation without orthodontic force application. The appliance and the surrounding tissue were studied radiographically, macroscopically, and histologically. The results were as follows: 1. The lateral radiographs taken after euthanasia showed very slight displacement of the vortical plate in the experimental animals, compared with the control animal. Mobility test of all animals confirmed primary stability without any increase of mobility during experimental period. 2. No pathologic changes were found in the healing condition of covering soft tissue and bone-screw interface in experimental animals as well as a control animal. 3. Osseointegration was achieved in the bone-screw interface in 8weeks after implantation and the amount of osseointegration increased in 18weeks. There was little difference of osseointegration between the compression side and the tension side. 4. In the marginal bone area, slight bone apposition and resorption were found regardless of compression and tension side, while there was no change in the control animal. 5. Both 8week-animal and 18week-animal showed the new bone apposition along the surface of screws which were perforated into the nasal cavity, while the control animal showed no change. 6. After 4weeks of plate removal, the covering epithelium was repaired intactly, while the connective tissue showed loose and irregular rearrangement and the connective tissue capsule remained. The C-Palatal $Plate^{TM}$ manifested sufficient anchorage capacity in the context of histological study as well as clinical outcomes, when immediate orthodontic force was applied after implantation.