• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.535-563
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• 1993

New techniques for regenerating the destructed periodontal tissue have been studied for many years. Current acceptable methods of promoting periodontal regeneration alre basis of removal of diseased soft tissue, root treatment, guided tissue regeneration, graft materials, biological mediators. Platelet-derived growth factor (PDGF) is one of polypeptide growth factor. PDGF have been reported as a biological mediator which regulate activities of wound healing progress including cell proliferation, migration, and metabolism. The purposes of this study is to evaluate the possibility of using the PDGF as a regeneration promoting agent for furcation involvement defect. Eight adult mongrel dogs were used in this experiment. The dogs were anesthetized with Pentobarbital Sodium (25-30 mg/kg of body weight, Tokyo chemical Co., Japan) and conventional periodontal prophylaxis were performed with ultrasonic scaler. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree III furcation defect was made on mandibular second(P2) and fourth(P4) premolar. For the basic treatment of root surface, fully saturated citric acid was applied on the exposed root surface for 3 minutes. On the right P4 20ug of human recombinant PDGF-BB dissolved in acetic acid was applied with polypropylene autopipette. On the left P2 and right P2 PDGF-BB was applied after insertion of ${\beta}-Tricalcium$ phosphate(TCP) and collagen (Collatape) respectively. Left mandibular P4 was used as control. Systemic antibiotics (Penicillin-G benzathine and penicillin-G procaine, 1 ml per 10-25 1bs body weight) were administrated intramuscular for 2 weeks after surgery. Irrigation with 0.1% Chlorhexidine Gluconate around operated sites was performed during the whole experimental period except one day immediate after surgery. Soft diets were fed through the whole experiment period. After 2, 4, 8, 12 weeks, the animals were sacrificed by perfusion technique. Tissue block was excised including the tooth and prepared for light microscope with H-E staining. At 2 weeks after surgery, therer were rapid osteogenesis phenomenon on the defected area of the PDGF only treated group and early trabeculation pattern was made with new osteoid tissue produced by activated osteoblast. Bone formation was almost completed to the fornix of furcation by 8 weeks after surgery. New cementum fromation was observed from 2 weeks after surgery, and the thickness was increased until 8 weeks with typical Sharpey’s fibers reembedded into new bone and cementum. In both PDGF-BB with TCP group and PDGF-BB with Collagen group, regeneration process including new bone and new cementum formation and the group especially in the early weeks. It might be thought that the migration of actively proliferating cells was prohibited by the graft materials. In conclusion, platelet-derived growth factor can promote rapid osteogenesis during early stage of periodontal tissue regeneration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.198-204
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• 2016

This research studied the relevance of oral symptoms and fear to find solutions for prevention and treatment at the right time. The study was conducted over a three-month period from September to November 2015. College students who lived in the region of Busan were surveyed, and the data from 288 respondents were analyzed. The female students felt a higher level of fear in every item than the males. To be specific, there were statistically significant differences in postponing the appointment (p=0.014), tension during treatment (p=0.001), dread when making the appointment (p=0.001), dread upon arrival (p=0.001), dread in the waiting room (p=0.001), dread of dental smells (p=0.006), dread while undergoing anesthesia (p<0.001), dread when receiving an injection (p<0.001), dread when looking at a tool for tooth preparation (p<0.001), dread of the sound of a tool for tooth preparation (p<0.001), dread of the feelings of tooth preparation (p<0.001), dread during scaling(p<0.001), and apprehension about the entire treatment (p<0.001). Concerning the fear level according to oral symptom awareness, the respondents with dental caries experienced a higher level of fear in terms of treatment avoidance (p=0.001), physiological reactions (p=0.001) and overall Dental Fear Survey (DFS)(p=0.003), and the students whose teeth were broken had a higher level of fear in terms of treatment avoidance (p=0.010), stimulus factors (p=0.031) and overall DFS (P=0.019). The students who had a missing tooth felt a higher level of fear in terms of physiological reactions (p=0.019) and overall DFS (p=0.033), and the respondents with gingival pain felt a higher level of pain in terms of the stimulus factors (p=0.013) and overall DFS (p=0.034). Therefore, college students should be educated to visit a dental clinic when they are aware of any oral symptom, and methods to reduce the stimulus factors as much as possible should be considered carefully to relieve dental fear.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.271-278
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• 2012

Purpose: Recently implant surgical guides were used for accurate and atraumatic operation. In this study, the accuracy of two different types of surgical guides, positioning device fabricated and stereolithography fabricated surgical guides, were evaluated in four different types of tooth loss models. Materials and methods: Surgical guides were fabricated with stereolithography and positioning device respectively. Implants were placed on 40 models using the two different types of surgical guides. The fitness of the surgical guides was evaluated by measuring the gap between the surgical guide and the model. The accuracy of surgical guide was evaluated on a pre- and post-surgical CT image fusion. Results: The gap between the surgical guide and the model was $1.4{\pm}0.3mm$ and $0.4{\pm}0.3mm$ for the stereolithography and positioning device surgical guide, respectively. The stereolithography showed mesiodistal angular deviation of $3.9{\pm}1.6^{\circ}$, buccolingual angular deviation of $2.7{\pm}1.5^{\circ}$ and vertical deviation of $1.9{\pm}0.9mm$, whereas the positioning device showed mesiodistal angular deviation of $0.7{\pm}0.3^{\circ}$, buccolingual angular deviation of $0.3{\pm}0.2^{\circ}$ and vertical deviation of $0.4{\pm}0.2mm$. The differences were statistically significant between the two groups (P<.05). Conclusion: The laboratory fabricated surgical guides using a positioning device allow implant placement more accurately than the stereolithography surgical guides in dental clinic.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.359-370
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• 2012

The endodontically treated tooth is generally restored with post and core, owing to the brittle and the loss of large amount of tooth structure. The purpose of this study was to evaluate the clinical status of fixed prostheses to improve the quality of dental care. In order to assess the clinical status of fixed prostheses, a total of 101 individuals (aged 30-89, 66 women and 35 men loaded with 125 fixed prostheses) who treated in the Department of Prosthodontics, Pusan National University Dental Hospital, between January 1990 to December 2005 were examined. The results of this study were as follows: 1. Length of service of fixed prostheses was $9.7{\pm}3.4$ years (mean), 11.1 years (median). 2. Age and sex of patient was found to have no statistically significant influence on longevity of fixed prostheses (P>.05). 3. Location of fixed prostheses was found to have statistically significant influence on longevity of fixed prostheses (P<.05). The longevity of fixed prostheses was low in anterio-posterior combination region (median:9.2 years). 4. Longevity of fixed prostheses made of base metal ceramic(median:12.0 years) and noble metal ceramic (median:11.3 years) is long (P<.05). 5. Number of units in fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses (P>.05). 6. Condition of opposing dentition was found to have no statistically significant influence on longevity of fixed prostheses (P>.05). 7. Dental caries, periapical disease, tooth fracture were frequent complications. In 51.9% of the cases, abutment state after removing fixed prostheses was needed to be extracted.

• The korean journal of orthodontics
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• v.29 no.6 s.77
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• pp.689-698
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• 1999

Although the purpose of orthodontic treatment is to increase the function and aesthetics of the jaws as well as to increase stability, there are side effects from the treatment itself such as root resorption and alveolar bone resorption. Such resoiption of the apical root is unpredictable and may even proceed into the dentin layer. Once the process has begun, it is irreversible. By evaluating the effects of different oral habits, especially that ef nail biting, and their correlation with the root and the periodontal tissues, the appropriate biomechanics for orthodontic treatment can be taken into consideration. The possibility of root resorption and alveolar bone loss during orthodontic treatment can also be considered. Also, any legal problems that might occur may be pondered as well. Among the male md female patients of the ages 10~15, 63 were chosen as the test group with known nail biting habits at time of examination and within the same age range those without nail biting habits as the control group. The test group was composed of 30 males and 33 females. The control group had 31 males and 32 females. The result from this study were as follows : 1. Of the 63 patients of both the test and control groups, the male-to-female-ratio was 1:1, and had no statistically significant difference in male and female root resorption. 2. In comparing crown length of the test and control groups, no significant difference existed, but in root length, maxillary and mandibular right and left central incisors and mandibular right lateral incisors had a smaller value. (p<0.001) 3. Average crown-to-root ratio of the test group on the periapical view show a noticeably high value for the maxillary and mandibular right and left central incisors and mandibular right and left lateral incisors. (p<0.01) 4. In comparing and evaluating the alveolar bone loss measured from the cemento-enamel junction to the alveolar bone crest, mesial surfaces of the maxillary and mandibular right and left central incisors and distal surface of maxillary right central incisor of the test group showed greater loss of crestal bone than the control. (p<0.05)

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.2
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• pp.113-118
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• 2013

When losing many of the remaining teeth, the relation among them can be put into dynamically unfavorable situation. In the case that the patient without any incompatibilityto the denture, overdenture can be considered. Moreover, we can overcome the dynamical disadvantage, and improve the support, stability, and retention of the partial denture by using implant at the edentulous area. In this case, patient with crossed occlusion between few remaining teeth was treated with maxillary and mandibular partial denture. Single implant fixture was placed at the edentulous space, opposing to the maxillary teeth occluded, and $Locator^{(R)}$ attachment was connected. The patient's esthetic satisfaction was improved by ideally adjusting the tilted occlusal plane. Since the patient was satisfied both esthetically and functionally, and maintained stable during the clinical observation for 6 months after the treatment, we would like to report about it.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.4
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• pp.364-370
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• 2015

Fixed restoration using implants for patients with posterior partial edentulism is generalized technique. As patient demands increase, the functional and esthetic implant restoration to achieve similar results to lost natural teeth is becoming an important issue. It is inevitable to use customized CAD/CAM abutments rather than ready-made abutments for the creation of implant prosthesis which closely resembles natural teeth. Using CAD/CAM abutment made it possible to obtain natural emergency profiles for posterior implant prostheses, ensuring more comfortable, efficient management of oral hygiene. However, keratinized gingiva with sufficient width and height for a natural emergence profile is required to use a large diameter CAD/CAM abutment which ensures stability and esthetics of hard/soft tissue around the implants. In this case, for esthetical and functional implant zirconia prosthesis, soft tissue graft was performed and customized CAD/CAM abutments were used following ridge augmentation, sinus graft and implantation. Satisfactory results were obtained functionally and esthetically through periodic clinical evaluation, and I hereby report this case.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.291-298
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• 2017

It is challenging to produce esthetic implant restoration in the narrow anterior maxilla region where insufficient volume of alveolar bone could limit the angle and position of implant fixture, if preceding bone augmentation is not considered. Ideal angle and position of implant fixture placement should be established to reproduce harmonious emergence profile with marginal gingiva of implant prosthesis, bone augmentation considered to be preceded before implant placement occasionally. In this case, preceding bone augmentation has been operated before esthetic implant prosthesis in narrow anterior maxilla region. Preceded excessive bone augmentation in buccal area allowed proper angulation of implantation, which compensates unfavorable implant position. Provisional restorations were corrected during sufficient period to make harmonious level of marginal gingiva and interdental papilla. The definite restoration was fabricated using zirconia core based glass ceramic. Functionally and esthetically satisfactory results were obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.342-348
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• 2020

Anatomical changes in the facial and alveolar bones occur after multiple teeth are extracted. In the maxilla, the alveolar bone is absorbed in the direction and inclination of the root, and the remaining alveolar bone becomes shorter, reducing the diameter of the arch. In addition, as the nasolabial angle increases, the support of the lips and the aesthetics of the face are lost. This case reports a functional and aesthetically satisfactory results of full mouth rehabilitation with the implant-supported fixed prosthesis using a zirconia framework.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.677-683
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• 2008

The purpose of study was to compare the prevalences of severe early childhood caries(S-ECC) using two different diagnostic criteria. The subjects of this study included 401 preschool children from 36 to 71 months of the randomly selected seven nurseries in Iksan city. Severe early childhood caries was defined as (1) 1 or more cavitated, missing (due to caries), or filled smooth surfaces in primary maxillary anterior teeth or (2) a decayed, missing, or filled score of ${\geq}$4 (age 3), ${\geq}$5 (age 4), or ${\geq}$6 (age 5) surfaces. The prevalence determined by maxillary anterior caries and the prevalence determined by dmfs were 26.7%, 28.9% in 3 years, 32.4%, 30.4% in 4 years, 39.4%, 41.3% in 5 years, and 35.4%, 35.9% in all, respectively. The results suggest that the two diagnostic criteria of the severe early childhood caries yield almost the same results.