• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.461-474
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• 2005

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue and the repair of function. For more than a decade there have been many efforts to develop materials and methods of treatment to promote periodontal tissue regeneration. Recently many efforts are concentrated on the regeneration potential of material used in traditional medicine. Safflower(Carthamus tinctorius L.) seed extract(SSE) have long clinically used in Korea to promote bone formation and prevent osteoporosis. The purpose of this study was to examine the effects of SSE on bone formation in human osteoblastic cell line. Human fetal osteoblastic cell line(hFOB 1.19) was cultured with DMEM and SSE($1{\mu}g/ml$, $10{\mu}g/ml$, $100{\mu}g/ml$, $1mg/ml$) at $34^{\cdot}C$ with 5% $CO_2$ in 100% humidity. The proliferation, differentiation of the cell was evaluated by several experiments. Cell proliferation was significantly increased at $10{\mu}g/ml$, $100{\mu}g/ml$, 1mg/ml of SSE after 3 and 7 days incubation(p<0.05). Cell spreading assay was significantly increased at $100{\mu}g/ml$ of SSE after 3 days and $1{\mu}g/ml$, $10{\mu}g/ml$, $100{\mu}g/ml$, 1mg/ml of SSE after 7 days(p<0.05). Alkaline Phosphatase(ALP) level was significantly increased in $10{\mu}g/ml$, $100{\mu}g/ml$, 1mg/ml of SSE(p<0.05). Collagen synthesis was significantly increased at $10{\mu}g/ml$, $100{\mu}g/ml$, 1mg/ml of SSE(p<0.05). A quantified calcium accumulation was significantly increased at $10{\mu}g/ml$, $100{\mu}g/ml$ of SSE(p<0.05). ALP and osteocalcin mRNA was expressed in $100{\mu}g/ml$ of SSE by RT-PCR. These results indicate that SSE are capable of increasing osteoblasts mineralization and may play an important role in bone formation.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.172-177
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• 2015

PURPOSE. The purpose of this study was to evaluate cell toxicity due to ion release caused by galvanic corrosion as a result of contact between base metal and titanium. MATERIALS AND METHODS. It was hypothesized that Nickel (Ni)-Chromium (Cr) alloys with different compositions possess different corrosion resistances when contacted with titanium abutment, and therefore in this study, specimens ($10{\times}10{\times}1.5mm$) were fabricated using commercial pure titanium and 3 different types of Ni-Cr alloys (T3, Tilite, Bella bond plus) commonly used for metal ceramic restorations. The specimens were divided into 6 groups according to the composition of Ni-Cr alloy and contact with titanium. The experimental groups were in direct contact with titanium and the control groups were not. After the samples were immersed in the culture medium - Dulbecco's modified Eagle's medium[DMEM] for 48 hours, the released metal ions were detected using inductively coupled plasma mass spectrometer (ICP-MS) and analyzed by the Kruskal-Wallis and Mann-Whitney test (P<.05). Mouse L-929 fibroblast cells were used for cell toxicity evaluation. The cell toxicity of specimens was measured by the 3-{4,5-dimethylthiazol-2yl}-2,5-diphenyltetrazolium bromide (MTT) test. Results of MTT assay were statistically analyzed by the two-way ANOVA test (P<.05). Post-hoc multiple comparisons were conducted using Tukey's tests. RESULTS. The amount of metal ions released by galvanic corrosion due to contact between the base metal alloy and titanium was increased in all of the specimens. In the cytotoxicity test, the two-way ANOVA showed a significant effect of the alloy type and galvanic corrosion for cytotoxicity (P<.001). The relative cell growth rate (RGR) was decreased further on the groups in contact with titanium (P<.05). CONCLUSION. The release of metal ions was increased by galvanic corrosion due to contact between base metal and titanium, and it can cause adverse effects on the tissue around the implant by inducing cytotoxicity.

• Journal of Periodontal and Implant Science
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• v.39 no.1
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• pp.77-86
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• 2009

Purpose: Recombinant human bone morphogenetic protein-2(rhBMP-2) has been evaluated as potential candidates for periodontal and bone regenerative therapy. In spite of good prospects in BMP applications, there is economically unavailable for clinical use in dental area. The purpose of this study was to evaluate the osteogenic effect of rhBMP-2 produced by E.coli expression system. Materials and methods: Eight-mm critical-size calvarial defects were created in 48 male Sprague-Dawley rats. The animals were divided into 6 groups of 8 animals each. Each group received one of the following: Negative control(sham-surgery control), positive control(absorbable collagen sponge(ACS) alone) and experimental(ACS loaded with rhBMP-2). Defects were evaluated by histologic and histometric parameters following 2- and 8-week healing intervals. Results: The experimental group showed significant defect closure at 2 and 8weeks than the sham surgery and positive control groups. Moreover, the experimental group showed significantly greater new bone and augmented area than the other groups at both 2 and 8weeks. Conclusion: rhBMP-2 produced by E.coli expression system may be effective for bone regeneration.

• Journal of Periodontal and Implant Science
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• v.39 no.1
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• pp.87-94
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• 2009

Purpose: The aim of this study was to compare the effectiveness of hydroxyapatite containing toothpaste with positive control toothpastes in reducing dentine hypersensitivity. Materials and methods: This clinical trial was a double-blind, randomized, parallel group comparison of two, namely hydroxyapatite containing toothpaste and strontium chloride containing toothpaste. A total of 55 subjects were included in this study. The subjects were given randomly assigned one of the two toothpastes after received tooth brushing instruction at baseline. Some clinical indices(PI, GI, PD), verbal rating score(VRS) for sensitivity to stimulus, the effect in relieving sensitivity and visual analogue scale(VAS) for sensitivity at baseline, week 2, week 4 and week 8 were assessed. All data were evaluated by intention-to-treat analysis. Results: Overall, PI and GI scores were significantly reduced compare baseline in all groups(p<0.05). In addition, there was significant difference in PI at 4 weeks and in GI at 4, 8 weeks between groups. The proportions of subjects relieved sensitivity were 70.4% in experimental group and 57.1% in control group at 8 weeks respectively. The VRS for sensitivity to three kinds of stimuli and VAS for sensitivity decreased according to time, there was no overall difference between two groups(p>0.05). Conclusion: This study demonstrated that the new hydroxyapatite containing toothpaste was similarly effective in reducing dentine hypersensitivity with pre-existing benchmark toothpaste.

• Journal of Periodontal and Implant Science
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• v.37 no.4
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• pp.871-879
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• 2007

Purpose: The purpose of this study was to evaluate the bone regeneration of novel biodegradable amorphous calcium phosphate. Materials and Method: An 8-mm, calvarial, critical-size osteotomy defect was created in each of 20 male Sprague-Dawley rats(weight $250{\sim}300g$). The animals were divided into two groups of 10 animals each and allowed to heal for 2 weeks(10 rats). The first group was the control group and the other group was the experimental group which received the novel biodegradable calcium phosphate. Results: The healing of the calvarium in the control group was uneventful. The histologic results showed little bone formation in the control group. The experimental group which received the novel biodegradable calcium phosphate showed a normal wound healing. There were a lot of new bone formation around the biomaterial in 2 weeks. The bone formation increased in 8 weeks when compared to 2 weeks and there was a significant bone increase as well(P<0.01). The nobel biodegradable calcium phosphate showed statistical significance when compared to the control group (P<0.05). The novel biodegradable calcium phosphate in 8 weeks showed a significant increase in bone formation when compared to 2 weeks $(40.4{\pm}1.6)$(%). The biodegradable calcium phosphate which is made from mixing calcium phosphate glass(CPG), NaCO and NaOH solution, is biocompatible, osteoconductive and has a high potency of bone formation. Conclusion: We can conclude that the novel biodegradable calcium phosphate can be used as an efficient bone graft material for its biodegradability and osteoconductivity.

• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.181-192
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• 2007

Periodontal surgery as part of the treatment of periodontal disease is mainly performed 1) to gain access to diseased areas for adequate cleaning; 2) to achieve pocket reduction or elimination; and 3) to restore the periodontal tissues lost through the disease; i.e., a new attachment formation of periodontal regeneration. To accomplish the latter, often referred to as the ultimate goal of periodontal therapy, a number of surgical procedures have been advocated throughout the years. Clinical studies have demonstrated that considerable gain of clinical attachment and bone can be achieved following guided tissue regeneration (GTR) therapy of intrabony defects. The aim of this study was to analyse the radiographic bone changes 2-year after GTR using a bone graft material and nonresorbable membrane. Patients attending the department of periodontics of Kyungpook National University Hospital were studied. Patients had clinical and radiographic evidence of intrabony defect(s), 33 sites of 30 patients aged 32 to 56 (mean age 45.6) were treated by GTR with a bone graft material and nonresorbable membrane. Baseline and 2-year follow-up radiographs were collected and evaluated for this study. Radiographic assessment includes a bone fill, bone crest change, defect resolution, and % of defect resolution. Pre- and post-treatment differences between variables (maxilla and mandible, defect depth, defect angle, bone graft materials) using the paired t-test were examined. We observed $2.86{\pm}1,87mm$ of bone fill, $065{\pm}0.79mm$ of crestal resorption, $3.49{\pm}2.11mm$ of defect resolution, and $44.42{\pm}19.51%$ of percentage of defect resolution. Mandible, deeper initial defect depth, narrower initial defect angle showed greater bone fill, defect resolution, and % of defect resolution. But no difference was observed between xenograft and allograft. Outcome of GTR as a therapy of intrabony defect was better than other therapy, but herein, good oral hygiene maintenance as a anti-infective treatment and periodic recall check of patients are essential.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.1
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• pp.44-51
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• 2009

Purpose: We evaluated the results of surgical treatment for metastatic pathologic or impending pathologic fractures. Materials and Methods: From January 2004 to December 2007, 18 patients 19 cases were included. Male were 6 and female were 12. The mean age was 65.1. Mean follow up period was 15.2 months. Pathologic fractures were 14 and impending pathologic fractures were 5. MSTS score, periodic radiologic follow up and postoperative complications were evaluated. Results: The primary malignancies were 6 cases of multiple myeloma, 4 cases of renal cell carcinoma, 2 cases of cholangiocarcinoma, 2 cases of colon cancer, 2 cases of breast cancer and 2 cases of leiomyosarcoma. Metastatic lesions were 10 cases of femur, 4 cases of clavicle, 2 cases of humerus, 2 cases of tibia and 1 case of radius. Surgical options were curettage, cementation, internal fixation and arthroplasty. Mean MSTS score was 15.9. Postoperative complications were 1 case of infection, 1 case of local recurrence and 1 case of implant loosening. Ten patients were alive with disease, 8 patients died of disease. Conclusion: Surgical treatment of metastatic skeletal lesions allowed early ambulation and improving dexterity. It improved pain and emotional acceptance. Surgery is necessary for improving qualities of remaining lives.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.167-172
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• 2009

Purpose: We wanted to evaluate the results of treating acromioclavicular joint dislocation using an AO hook plate. Materials and Methods: Between February 2008 and September 2009, 10 patients underwent implant removal after surgical treatment of acromioclavicular joint dislocation using a AO hook plate. The Constant-Murley scoring system was administered postoperatively for evaluating the clinical results, and simple X-ray was taken for evaluating the state of reduction. Results: All cases showed satisfactory results on the clinical and radiological study. The mean Constant-Murley score at follow-up was 90.5 (range: 84~95). Three patients had some degree of discomfort with the hook plate, but these symptoms were relieved on removal of the plate. The radiological evaluation showed restoration of the vertical displacement of the clavicle in all the patients. No complications occurred such as infection, plate failure or redislocation after removal of the plate. Conclusion: The short term follow-up results of treating acromioclvicular joint dislocation using an AO hook plate were satisfactory both clinically and radiologically.

• Journal of Periodontal and Implant Science
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• v.49 no.1
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• pp.2-13
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• 2019

Purpose: The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy. Methods: Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses. Results: New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2. Conclusions: HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.

• Journal of Korean Dental Science
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• v.15 no.1
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• pp.1-8
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• 2022

Purpose: Intraoral scanners, desktop scanners, and cone-beam computed tomography (CBCT) are being used in a complementary way for diagnosis and treatment planning. Limited patient-based results are available about dimensional reproducibility among different three-dimensional imaging systems. This study aimed to evaluate dimensional reproducibility among patient-derived digital models created from an intraoral scanner, desktop scanner, and two CBCT systems. Materials and Methods: Twenty-nine arches from sixteen patients who were candidates for implant treatments were enrolled. Different types of CBCT systems (KCT and VCT) were used before and after the surgery. Polyvinylsiloxane impressions were taken on the enrolled arches after the healing period. Gypsum casts were fabricated and scanned with an intraoral scanner (CIOS) and desktop scanner (MDS). Four test groups of digital models, each from CIOS, MDS, KCT, and VCT, respectively, were compared to the reference gypsum cast group. For comparison of linear measurements, intercanine and intermolar widths and left and right canine to molar lengths were measured on individual gypsum cast and digital models. All measurements were triplicated, and the averages were used for statistics. Bland-Altman plots were drawn to assess the degree of agreement between each test group with the reference gypsum cast group. A linear mixed model was used to analyze the fixed effect of the test groups compared to the reference group (α=0.05). Result: The Bland-Altman plots showed that the bias of each test group was -0.07 mm for CIOS, -0.07 mm for MDS, -0.21 mm for VCT, and -0.25 mm for KCT. The linear mixed model did not show significant differences between the test and reference groups (P>0.05). Conclusion: The linear distances measured on the digital models created from CIOS, MDS, and two CBCT systems showed slightly larger than the references but clinically acceptable reproducibility for diagnosis and treatment planning.