• Journal of Periodontal and Implant Science
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• v.32 no.4
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• pp.769-779
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• 2002

This present study was carried out to find the effects of calcium aluminate cement($CaO\;{\cdot}\;Al_2O_3$, CAC), which has been developed with bio-compatibility and mechanical properties, in biological environments. Two different particle sizes of CAC - 3.5${\mu}m$ vs. 212${\sim}$250${\mu}m$ which is recommended in periodontal bone grafting procedures-were filled in 8mm calvarial defect in Sprague-Dawley rat. The specimens were examined histologically, especially the bone-cement interface and the response of surrounding tissues. The results are as follows; 1. In the control group, inflammatory cells were observed at 2 weeks. At 8 weeks, periosteum and dura mater were continuously joined together in the defect areas. But in the center of defect area were filled up with the loose connective tissues. 2. In the experimental group l($212{\mu}m{\sim}250{\mu}m$ particle), immature bone was formed and outermost layer was surrounded by osteoid layer at 2 weeks. Osteoblasts were arranged between immature bone and osteoid layer. And, osteoid layer was remained until 8 weeks after surgery. 3. In the experimental group 2, periosteum and dura mater lost its continuity at 2 weeks. Scattering of CAC particles and infiltration of inflammatory cells were observed, which this findings deepened at 8 weeks. The result of this study shows that when calvarial defects in white rats are filled with calcium aluminate cement of 212${\sim}$250${\mu}m$, the materials are to be bio-compatible in growth and healing on surrounding tissues. When further researches are fulfilled, such as direct bone adhesion and bone regeneration ability, it's possible that CAC could be applied to various periodontology fields in the future.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.3
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• pp.295-300
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• 2009

Statement of problem: As the number of elders is growing with the advancement of medicine, partially or fully edentulous patients have increased. Medically compromised conditions are common in the older population so that it should be taken into account in prosthetic treatment planning as well as their economic conditions. In the older patients, removable prosthesis has been preferred to implant prosthesis. However, cast metal based removable partial dentures also has several limitations. Purpose: In this report, we present several cases of Valplast$^{(R)}$ flexible denture which were fabricated in patients who had medically compromised conditions or whose remaining teeth showed a relatively poor prognosis. Results & Conclusion: This article describes an alternative treatment for a partially edentulous patient with mouth opening limitation, after cancer surgery, compromised general condition and questionable remaining teeth. In these patients, Valplast$^{(R)}$ flexible denture was used because of its unique characteristics and the results were all satisfactory. Patients had 1-2 check-up and there were no postoperative pain or fracture of denture up to now.

• Journal of Periodontal and Implant Science
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• v.45 no.3
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• pp.111-119
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• 2015

Purpose: The purpose of this animal study was to perform a histological and histomorphometric analysis in order to elucidate the effect of fibroblast growth factor-2 (FGF-2) on injured periodontal ligament (PDL) and cementum after tooth replantation in dogs. Methods: The roots of 36 mandibular premolars from six mongrel dogs were used in this study. The roots were randomly divided into three groups: (1) a positive control group (n=12), in which the PDL was retained; (2) a negative control group (n=12), in which the PDL and the cementum between the notches were removed; and (3) an experimental group (n=12), in which the PDL and the cementum between the notches were removed and the roots were soaked in an FGF-2 solution ($30{\mu}g/0.1mL$). After treating the root surfaces, the extracted roots were replanted into extraction sockets. The animals were sacrificed four and eight weeks after surgery for histologic and histomorphometric evaluation. Results: At four and eight weeks, normal PDLs covered the roots in the positive control group. In the negative control group, most replanted roots showed signs of replacement resorption. In the experimental group, new PDL-like tissue and cementum-like tissue were observed to partially occupy the region between the root surfaces and the newly formed bone. Histomorphometric analysis showed that the mean length of the newly formed cementum-like tissue on the roots treated with FGF-2 was significantly greater than that of the tissue on the roots in the negative control group (four weeks, P=0.008; eight weeks, P=0.042). However, no significant differences were observed between the roots treated with FGF-2 and the negative control roots with respect to newly formed PDL-like tissue. Conclusions: The results of this study suggest that use of FGF-2 on injured root surfaces promotes cementogenesis after tooth replacement in dogs.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.1
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• pp.1-8
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• 2017

Purpose: The purpose of this study is to compare the accuracy of the CT guided implant template that was produced by using an intraoral scanner according to the edentulous distance. Materials and methods: Five maxillary casts were fabricated using radiopaque acrylic resin with the second premolars, first molars, and second molars missing. Then a virtual cast was acquired by scanning each resin cast. Implant treatment was planned on the missing sites by superimposing the presurgical CT DICOM file and the virtual cast. Then the implants were placed using a surgical template followed by postsurgical CT scan. The distance and angle of the platform and apex between the presurgical implant and postsurgical implant were measured using the X, Y, and Z axis of the superimposed presurgical CT and postsurgical CT via software followed by statistical analysis using Kruskall-Wallis test and Mann-Whitney test. Results: The implant placement angle error increased towards the second molars but there was no statistically significant difference. The implant placement distance error at the platform and apex also increased towards the second molars and there was a statistically significant error at the second molars. Conclusion: Although the placement angle had no statistically significant difference between the presurgical implant and postsurgical implant, the placement distance at the platform and apex showed a larger error and a statistically significant difference at the second molar implant.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.270-277
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• 2002

Since founded in 1959, it's well known that the KAPD has pioneered in the researches and clinical aspects of pediatric dentistry in Korea. It's official journal, the Journal of the KAPD, was first published in 1974 and has pressed total 956 articles up to now(March, 2001). In this study, all the articles pressed in this journal have been surveyed, focussing in their main theme, their chronological and thematic distribution. The thematic classification was made with the reference of the previous studies and renowned textbooks in pediatric dentistry. And we obtained the results as follows: 1. The researches on dental materials and dental equipments have shown continuous increase throughout the period. 2. The researches on dental caries, caries prevention and systemic disorders have occupied relatively high proportion consistently. 3. The researches on malocclusions and cysts/minor surgery have shown increasing tendency in the second period, but are decreasing in the third period. 4. The researches on craniofacial growth/development, tooth development/eruption, developmental disorders of teeth, management of eruption space have shown decreasing tendency. 5. The researches on behavioral research, oral habits, occlusion of primary-mixed dentition have shown very low proportion, reaching no more than 1% throughout the period.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.323-330
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• 2004

The purpose of this study was to evaluate the diagnostic validity of early proximal caries lesions using laser fluorescence and whether the detection could be enhanced using a fluorescent dye. Direct visual examination and bitewing radiograph were used for comparison. The subjects of this study were 30 children of $3{\sim}9$ years old. Laser fluorescence and dye-enhanced laser fluorescence(mixed wavelength of 488 and 514 nm) were used and viewed through glasses(excluding wavelength<520 nm). For dye-enhanced laser fluorescence a 0.075% sodium fluorescein dye was applied before examination. Proximal caries lesion of each subject was assessed using visual examination, bitewing radiograph, laser fluorescence, and dye-enhanced laser fluorescence. The results in the three detection methods were compared to the assessment of bitewing radiograph. The results from the present study can be summarized as follows: 1. There was highly correlation(r=0.725-0.911) between the bitewing radiograph and all three detection methods(p<0.05) 2. The reproducibility(kappa value) of the visual examination, laser fluorescence and dye-enhanced laser fluorescence comparing with bitewing radiograph of proximal caries was 0.451, 0.683, 0.772, respectively. There was highest correlation between dye-enhanced laser fluorescence and bitewing radiograph for detection of proximal caries. The results from this study indicated that the dye-enhanced laser fluorescence considered to be accurate and reliable method in detecting proximal caries.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.247-255
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• 2004

The purpose of this study was to examine the effects of resin composite monomers (Bis-GMA, TEGDMA, EGDMA, UDMA, HEMA, Camphorquinone) on the growth of the two cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus. We obtained the following results : 1. The growth rate of S. mutans and S. sobrinus was decreased significantly in the group of all composite resin monomer at a concentration of 0.03mmo1/L(P<0.01). 2. The growth rate of S. mutars in the group of UDMA at a concentration of 0.01 mmol/L and the group of CQ at a concentration of 0.005 mmol/L, 0.01 mmol/L was decreased significantly compared to the control group(P<0.01). 3. The growth rate of S. sobrinus in the group of HEMA, UDMA at a concentration of 0.01 mmol/L and the group of CQ at a concentration of 0.005mmol/L. 0.01mmo1/L was decreased significantly compared to the control group (P<0.01). 4. The growth rate of S. sobrinus in the group of EGDMA at a concentration of 0.001, 0.01, 0.03mmo1/L was decreased significantly compared to the control group(P<0.01) and were showed to be statistically significant difference between experimental groups(P<0.01).

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.88-94
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• 2011

Ranula is a mucosal cyst that occurs in the mouth floor. This is a pseudo cyst caused by mucous retention within the tissue due to the rupture of catheter in the salivary gland. Ranula occurs mainly in a unilateral form and is characterized by painless bluish transparent swelling, with a increasing mass size. If the size is large, it can cause discomfort during swallowing, pronounciation, and mastication, but external swelling and infection is rare. Treatments include observation for spontaneous resolution, simple incision and drainage, marsupialization and excision. Marsupialization done by removing parts of the cyst wall and connecting it to the oral mucosa. It is a conservative procedure and recommended for children. It has advantages such as maintaining outline of oral tissue and less risk of damaging anatomic structure. Recurrence is common, mostly occurring within 4 months after surgery. This case is about a eight-year-old girl with ranula on the right mouth floor. This patient was treated with marsupialization that is one of treatment for ranula, and recurrence was not observed.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.2
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• pp.111-120
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• 2010

Purpose: This investigation was designed to evaluate the condyle position and the symmetry of the both condyle heads at the maximum intercuspal position on the sagittal CT image of the temporomandibular joint. Materials and Methods: Cone-beam CT was used to assess 400 joints in 100 symptom and 100 symtom-free subject(100 male, 100 female). Three independent observers(dentists) determined the positions classified with Anterior Position(AP), Middle Position(MP), and Posterior Position(PP), and the symmetry of the both condyle. Results: According to gender, the mean percentages of AP, MP, and PP were 48.5, 28.5, and 23 in male group, and 34, 38, and 28 in female group. The symmetry of condylar heads was more common than asymmetry in the both of groups. In the respect of symptom or symptom-free, the mean percentages of AP, MP, and PP were 44.5, 34, and 21.5 in the symptom-free group, and 37, 33.5, and 29.5 in the symptom group. The symmetry of condylar heads was more common in the symptom-free group, but the asymmetry of condylar heads was more common in the symptom group. Conclusions: These data might serve as useful criteria for the clinical assessment of condyle position at the maximum intercuspal position optained by Cone-beam CT.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.272-279
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• 2013

The concept of implant stability was basically originated from the relative condition of bone-implant interface and has some meanings for evaluation of that interface. In addtion, it has been used for the investigation of initial bone healing process after fixture installation because a degree of micromotion around interface can affect unfavorable clinical results. The purpose of this study is to investigate the mode of initial bone healing from fixture installation through prospective trial. Thirty fixtures were consecutively installed in mandibles of 26 patients with single tooth loss area and then healing abutment were secured for one-stage surgery meothod. Resonance frequency analysis was performed with one week interval during 12 weeks and periapical radiographs were taken at each month. Although marginal bone level change was not shown through observation period (P>0.05), statistical difference of implant stability was shown through 4 and 6 week (P<0.05) and was not shown after 6 week (P>0.05) according to the bone quality. Initial bone healing process is a successive process of bone resorption and favorable bone healing result might be postulated at 4 week interval after installation through RFA.