• Journal of Periodontal and Implant Science
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• v.43 no.4
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• pp.147-152
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• 2013

Purpose: An animal periodontitis model is essential for research on the pathogenesis and treatment of periodontal disease. In this study, we have introduced a lipopolysaccharide (LPS) of a periodontal pathogen to the alveolar bone defect of experimental animals and investigated its suitability as a periodontitis model. Methods: Alveolar bone defects were made in both sides of the mandibular third premolar region of nine beagle dogs. Then, the animals were divided into the following groups: silk ligature tied on the cervical region of tooth group, Porphyromonas gingivalis LPS (P.g. LPS)-saturated collagen with silk ligature group, and no ligature or P.g. LPS application group as the control. The plaque index and gingival index were measured at 0 and 4 weeks postoperatively. The animals were then euthanized and prepared for histologic evaluation. Results: The silk ligature group and P.g. LPS with silk ligature group showed a significantly higher plaque index at 4 weeks compared to the control (P<0.05). No significant difference was found in the plaque index between the silk ligature group and P.g. LPS with silk ligature group. The P.g. LPS with silk ligature group showed a significantly higher gingival index compared to the silk ligature group or the control at 4 weeks (P<0.05). Histologic examination presented increased inflammatory cell infiltration in the gingival tissue and alveolar bone of the P.g. LPS with silk ligature group. Conclusions: An additional P.g. LPS-saturated collagen with silk ligature ensured periodontal inflammation at 4 weeks. Therefore, P.g. LPS with silk ligature application to surgically created alveolar bone defects may be a candidate model for experimental periodontitis.

• Journal of Periodontal and Implant Science
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• v.40 no.5
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• pp.232-238
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• 2010

Purpose: To prolong the degradation time of collagen membranes, various cross-linking techniques have been developed. For cross-linking, chemicals such as formaldehyde and glutaraldehyde are added to collagen membranes, but these chemicals could adversely affect surrounding tissues. The aim of this study is to evaluate the ability of porous non-chemical cross-linking porcine-derived collagen nanofibrous membrane to enhance bone and associated tissue regeneration in one-wall intrabony defects in beagle dogs. Methods: The second and third mandibular premolars and the first molars of 2 adult beagles were extracted bilaterally and the extraction sites were allowed to heal for 10 weeks. One-wall intrabony defects were prepared bilaterally on the mesial and distal side of the fourth mandibular premolars. Among eight defects, four defects were not covered with membrane as controls and the other four defects were covered with membrane as the experimental group. The animals were sacrificed 10 weeks after surgery. Results: Wound healing was generally uneventful. For all parameters evaluating bone regeneration, the experimental group showed significantly superior results compared to the control. In new bone height (NBh), the experimental group exhibited a greater mean value than the control ($3.04{\pm}0.23\;mm/1.57{\pm}0.59$, P=0.003). Also, in new bone area (NBa) and new bone volume (NBv), the experimental group showed superior results compared to the control (NBa, $34.48{\pm}10.21%$ vs. $5.09{\pm}5.76%$, P=0.014; and NBv, $28.04{\pm}12.96$ vs. $1.55{\pm}0.57$, P=0.041). On the other hand, for parameters evaluating periodontal tissue regeneration, including junctional epithelium migration and new cementum height, there were no statistically significant differences between two groups. Conclusions: Within the limitations of this study, this collagen membrane enhanced bone regeneration at one-wall intrabony defects. On the other hand, no influence of this membrane on periodontal tissue regeneration could be ascertained in this study.

• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.299-302
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• 2002

Selectins are differentially expressed carbohydrate binding proteins involved in the initiation of tissue inflammation by mediating the rolling and tethering of leukocytes on the vascular endothelium. This primary event in initiation of inflammation, as occurs during reperfusion injury, can be therapeutically targeted using selectin inhibitors, which generally block binding of sLex to E-, P-, and L-selectins. The objective of this study was to determine the role of selectins in renal ischemia/reperfusion injury after kidney transplantation. Canine kidneys were subjected to 60-min warm ischemia, flushed with UW solution, cold stored for 24 h, and autotransplanted into the nephrectomized donor. Renal autografts were monitored for 7 days by serum creatinine in the first study and by histology and myeloperoxidase activity after 4-hour reperfusion in the second study. In each study, one group of animals received TBC1269 (selectin inhibitor) and the other received saline vehicle. Serum creatinine rose quickly after transplantation and was not different between the groups. TBC1269 abolished a reperfusion-induced 2-fold increase in renal cortex neutrophil infiltration and improved histologic signs of ischemia after 4 hours of reperfusion. Selectin blockade does not improve the course of injury caused by warm renal ischemia. A minor benefit associated with the inhibition of early inflammation during reperfusion after kidney transplantation seems to occur.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.325-330
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• 2007

This study was to determine whether canine model which produce acute permanent joint instability in short period without postoperative exercise have a degenerative changes and also evaluated its suitability as an appropriate animal OA models. Ten skeletally mature beagle dogs underwent a unilateral surgical transection of the cranial cruciate ligament and, the medial collateral ligament as well as a medial meniscectomy. The contra-lateral joint was used as control. After 12 weeks, After 12 weeks, the amount of joint damage, inflammation and biochemical change of synovial fluid was evaluated. Histological analysis showed chondrocyte clone formation, hypertrophy of the cartilage and moderate loss of proteoglycans in the experimental joints compared to control joints. In addition, the synovial inflammation in the experimental joints was observed. Biochemical analysis of SF showed significantly increased MMP (matrix metalloproteinase) -2 and -9 in experimental joints compared to control joints. This canine OA model shows the characteristics of degenerative joint disease, and may have a advantages of reducing the time and cost because postoperative exercise is not needed in this OA model.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.338-350
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• 2022

Purpose: Various studies have investigated 3-dimensional (3D)-printed implants using Ti6Al-4V powder; however, multi-root 3D-printed implants have not been fully investigated. The purpose of this study was to explore the stability of multirooted 3D-printed implants with lattice and solid structures. The secondary outcomes were comparisons between the 2 types of 3D-printed implants in micro-computed tomographic and histological analyses. Methods: Lattice- and solid-type 3D-printed implants for the left and right mandibular third premolars in beagle dogs were fabricated. Four implants in each group were placed immediately following tooth extraction. Implant stability measurement and periapical X-rays were performed every 2 weeks for 12 weeks. Peri-implant bone volume/tissue volume (BV/TV) and bone mineral density (BMD) were measured by micro-computed tomography. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were measured in histomorphometric analyses. Results: All 4 lattice-type 3D-printed implants survived. Three solid-type 3D-printed implants were removed before the planned sacrifice date due to implant mobility. A slight, gradual increase in implant stability values from implant surgery to 4 weeks after surgery was observed in the lattice-type 3D-printed implants. The marginal bone change of the surviving solid-type 3D-printed implant was approximately 5 mm, whereas the value was approximately 2 mm in the lattice-type 3D-printed implants. BV/TV and BMD in the lattice type 3D-printed implants were similar to those in the surviving solid-type implant. However, BIC and BAFO were lower in the surviving solid-type 3D-printed implant than in the lattice-type 3D-printed implants. Conclusions: Within the limits of this preclinical study, 3D-printed implants of double-rooted teeth showed high primary stability. However, 3D-printed implants with interlocking structures such as lattices might provide high secondary stability and successful osseointegration.

• Journal of Periodontal and Implant Science
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• v.53 no.2
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• pp.120-134
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• 2023

Purpose: We investigated whether repeated irradiation with light-emitting diodes (LEDs) at a combination of 470 nm and 525 nm could suppress the progression of experimental periodontitis. Methods: A experimental periodontitis model was established in the second, third, and fourth premolars of the mandible in beagle dogs for 2 months. The spontaneous progression of periodontitis was monitored under the specified treatment regimen for 3 months. During this period, the animals were subjected to treatments of either plaque control only (control) or plaque control with LED application (test) at 2-week intervals. The clinical parameters included the probing pocket depth (PPD), gingival recession (GR), and the clinical attachment level (CAL). Histomorphometric analysis was performed using measurements of the length of the junctional epithelium, connective tissue (CT) zone, and total soft tissue (ST). Results: There were significant differences in PPD between the control and test groups at baseline and 12 weeks. When the change in PPD was stratified based on time intervals, it was shown that greater differences occurred in the test group, with statistical significance for baseline to 12 weeks, 6 to 12 weeks, and baseline to 6 weeks. There was no significant difference in GR between the control and test groups at any time points. Likewise, no statistically significant differences were found in GR at any time intervals. CAL showed a statistically significant difference between the control and test groups at baseline only, although significant differences in CAL were observed between baseline and 12 weeks and between 6 and 12 weeks. The proportion of CT to ST was smaller for both buccal and lingual areas in the control group than in the test group. Conclusions: Repeated LED irradiation with a combination of 470-nm and 525-nm wavelengths may help suppress the progression of periodontal disease.

• Journal of Periodontal and Implant Science
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• v.53 no.2
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• pp.157-169
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• 2023

Purpose: The aim of this study was to evaluate the impact of polydeoxyribonucleotide (PDRN) on histologic outcomes when implant placement and lateral sinus floor elevation are performed simultaneously. Methods: Three bimaxillary premolars (P2, P3, and P4) were extracted from 4 beagle dogs 2 months before lateral sinus floor elevation. After lateral elevation of the sinus membrane, each sinus was allocated to either the test or control group. Sinuses underwent either 1) collagenated synthetic bone graft with PDRN following lateral sinus floor elevation (test group) or 2) collagenated synthetic bone graft without PDRN after lateral sinus floor elevation (control group). Eight weeks after the surgical procedure, all animals were euthanised for a histologic and histomorphometric assessment. Augmented height (AH), protruding height (PH), and bone-to-implant contact in pristine (BIC_p) and augmented (BIC_a) bone were measured. The composition of the augmented area, which was divided into 3 areas of interest located in coronal, middle and apical areas (AOI_C, AOI_M, and AOI_A), was calculated with 3 parameters: the area percentage of new bone (pNB), residual bone graft particle (pRBP), and fibrovascular connective tissue (pFVT). Results: AH, PH, BIC_p, BIC_a total, BIC_a coronal, and BIC_a middle values were not significantly different between sinuses in the control and test groups (all P>0.05). The BIC_a apical of sinuses in the test group (76.7%±9.3%) showed statistically higher values than those of sinuses in the control group (55.6%±22.1%) (P=0.038). pNB, pRBP, and pFVT showed statistically significant differences between the 2 groups in AOI_A (P=0.038, P=0.028, and P=0.007, respectively). pNB, pRBP, and pFVT in AOI_C and AOI_M were not significantly different between samples in the control and test groups (all P>0.05). Conclusions: The histologic findings revealed that lateral sinus floor elevation with PDRN might improve early new bone formation and enable higher bone-to-implant contact.

• Analytical Science and Technology
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• v.20 no.2
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• pp.138-146
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• 2007

A simple and sensitive method for the determination of paroxetine in canine plasma was developed and validated by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry (LC-/MS/MS). Fluoxetine was used as an internal standard. Paroxetine and internal standard in plasma samples were extracted using TBME (tert-butyl methyl ether). A centrifuged upper layer was then evaporated and reconstituted with mobile phase of 50% acetonitrile adjusted to pH 3 by formic acid. The reconstituted samples were injected into a Capcell Pak UG120 ($2.0{\times}150mm$, $5{\mu}m$) column. Using MS/MS with SRM (selective reaction monitoring) mode, the transitions (precursor to product) monitored were m/z $330{\rightarrow}192$ for paroxetine, and m/z $310{\rightarrow}148$ for internal standard. Linear detection responses were obtained for paroxetine concentration range of 0.02~5 ng/mL. A correlation coefficient of linear regression ($R^2$) was 0.9993. Detection of paroxetine in canine plasma was accurate and precise, with limit of quantification at 0.02 ng/mL. The method has been successfully applied to pharmacokinetic study of paroxetine in healthy beagle dogs.

• The korean journal of orthodontics
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• v.38 no.6
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• pp.416-426
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• 2008

The purpose of this study was to evaluate the mobility and ratio of the bone-implant contact (BIC) of a sandblasted, large grit and acid-etched (SLA) orthodontic micro-implant. Methods: Ninety-six micro-implants (48 SLA and 48 machined) were implanted in the upper and lower buccal alveolar bone, and palatal bone of four beagle dogs. Two weeks after surgery, orthodontic force (150-200 g) was applied. Two beagles were sacrificed at 4-weeks and the other two at 12-weeks. Histomorphometric comparisons were made between the SLA experimental group and the machined micro-implant as a control group to determine the ratio of contact between the bone and implant. Micro-implant mobility was also evaluated using $Periotest^{(R)}$. Results: Periotest values showed no statistically significant difference in the upper alveolar and palatal bone between groups except for the lower buccal area. BIC in the upper buccal area showed no significant difference between groups both at 4-weeks and 12-weeks. However, both the groups showed a significant difference in BIC ratio in the rest of the experimental areas between 4 weeks and 12 weeks. The experimental group showed active bone remodeling around the bone-implant interface compared to the control group. Conclusions: There were significant differences in the BIC and the Periotest values between the surface-treated and machined micro-implants according to bone quality in the early stage.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.173-185
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• 2001

The orthodontic osseointegrated titanium implant, a kind of intraoral skeletal anchorage can be an alternative to tooth-borne anchorage, in case that the conventional tooth-borne anchorage is not available or the anchorage is critical. This study was conducted to elucidate the effect of early loading on the osseointegration of the orthodontic titanium implant and the healing process of the impaired bone at the site of implant after removing it. In two adult beagle dogs24 osseointegrated titanium implants were inserted into the alveolar bone, with 12 implants placed in each dog. In dog1, 6 out of 12 implants were loaded with 200-300gm of force immediately after placing, and the remaining 6 implants were not loaded for 4weeks. In dog2, all 12 implants had healing period of 4weeks, and then were loaded with 200-300gm of force for another 4weeks. Following an observation period of 4 and 8 weeks, the animals were sacrificed. Then the implants and the surrounding bone of dog1 and dog2 were removed, respectively. Undecalcified sections along the long axis of implant were made and the degree of osseointegration was examined under the light microscope. The results were as follows. 1. In the histologic features of tissues around implants anchored in dog1, there was no difference between immediately loaded implants and unloaded implants. Immature woven bone was ingrowing into the thread spaces from the original compacta and in direct contact with the implant surface in part. 2. The premature loading just after 4weeks healing period did not halt the progress of the osseointegration between bone and implant surface. The woven bone around the implants was maturing into the lamellar bone which resembled the structure of the original compacta at the end of 8weeks observation period. 3. Most implants with the inflammed surrounding mucosa were lost or mobile. The mobile implants were encapsulated by fibrous connective tissue which separated the implant surface from the bone. 4. The impaired bone at the site of the implant failed to anchor was showing recovery without inflammatory reaction 2weeks after removing, with the immaure woven bone lined by active osteoblasts and osteoid. Based on the results of this study, the integration of this orthodontic implant seemed to be impaired by the inflammation of the tissue surrounding the Implant rather than by early loading on implant, and increased with time lapsed after placing the implant. The use of implant described in this report can be recommended as an orthodontic anchorage unit immediately after insertion under the careful control of orthodontic force applied and plaque.