• Journal of Korean society of Dental Hygiene
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• v.14 no.1
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• pp.101-108
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• 2014

Objectives : The purpose of this study was to evaluate the tooth whitening effect of 0.74% and 2.80% hydrogen peroxide toothpastes and safety on tooth and gingival tissue. Methods : Toothpastes containing 0.74% and 2.80% hydrogen peroxide were evaluated. In in-vitro test, some additives (sodium metaphosphate, sodium pyrophosphate and titanium dioxide) were added to the toothpastes. Hydroxyapatite specimens (HAPs) were made and stained using modified Stookey's methods. HAPs were treated for 1 hour at shaking incubator and brushed for 1,000 times as 250 gF with each diluted toothpaste. Before and after color was measured by colorimeter. Using double blind method, 99 Korean with natural maxillary anterior teeth were selected and the initial brightness (baseline) was measured by SHADEEYE-EX. Based on this measurement they were crossly distributed into control group (0% hydrogen peroxide), test 1 (0.74% hydrogen peroxide) and test 2 (2.80% hydrogen peroxide). After 2 weeks, people of each group were provided toothpaste and told to use 3 times a day right after every meal for 3 minutes. The brightness of teeth was measured 3 times for every one month. Results : ${\Delta}L$ was statistically significant among three groups in shaking test. ${\Delta}L$ of two test groups was statistically significant compared with control group but not between each test group in brushing test. After using toothpaste for 3 months, test 1 group and test 2 group were 15.89% and 31.23% more whitened compared with control group respectively (p<0.05). Rate of more whitened person of each test group was 24.2% and 40.5% more than control group respectively (p<0.05). There was no difference in the hypersensitivity during 3 months using toothpastes and no side effect on teeth or gums. Conclusions : Toothpastes containing 0.74% and 2.80% hydrogen peroxide showed tooth whitening effect and both were safe enough to use for tooth whitening.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.149-159
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• 2000

Occlusal disease is comparable to periodontitis in that it is generally not reversible. Occlusal disease, however, like periodontitis, often maintainable. It does itself to treatment and when restorative dentistry is utilized it becomes, in that sense, reversible. Moreover, a systematized and integrated approach will lead to a prognosis that is favorable and predictable. This approach facilitates development of optimum oral function, comfort, and esthetics, resulting in a satisfied patient. Such a systematized approach consists of four logical phase : (1) patient evaluation, (2) comprehensive analysis and treatment planning, (3) integrated and systematic reconstruction, and (4) postoperative maintenance. An integrated treatment plan is first developed on one set of diagnostic casts, properly mounted on a semiadjustable articulator using jaw relationship records. This is accomplished by using wax to make reconstructive modifications to the casts. These modified casts become the blueprint for planned occlusal changes and the fabrication of provisional restorations. The treatment goals are : (1) comfortably functioning temporomandibular joints and stomatognathic musculature, (2) adherence to the basic principle of occlusion advocated by Schuyler, (3) anterior guidance that is in harmony with the envelope of function, (4) restorations that will not violate the patient's neutral zone. This report shows the treatment procedures for a patient whose mandibular position has been altered due to posterior bite collapse. Migration of the maxillary anterior teeth had occurred, and the posterior occlusal contacts showed pathologic interference. Precise diagnosis using mounted casts was executed and prosthodontic reconstruction by the aid of an unconventional orthodontic correction on maxillary flaring was planned. An unconventional orthodontic correction can be accomplished by using preexisting natural teeth, which can be modified for use in active tooth movement or splinted together for orthodontic anchorage. This technique has an advantage over conventional fixed appliance orthodontic therapy because it can accomplish tooth movement concurrently with restorative and periodontal therapy. On occasion, minor tooth movement can be necessary to achieve the optimum occlusal scheme, crown form, and tooth position for the forces of occlusion to be displaced down the long axis of the periodontally compromised teeth. Once the occlusion, periodontal health, and crown contours for the provisional splinted restoration are acceptable, the final splinted restoration can be similarly fabricated, and it becomes an excellent orthodontic retainer.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.2
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• pp.201-209
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• 2021

In removable partial dentures, many types of retentive systems have been studied and applied in clinical treatment. One of those systems is the double crown denture system which is widely used in European countries such as Germany and Sweden. Telescopic double crown dentures have several advantages such as convenience in maintaining oral hygiene, enabling to transfer occlusal force along the long axis of the abutment, and secondary splinting effect between the abutments which leads to higher clinical performance compared to conventional removal partial dentures. In this clinical case, the patient was initially restored with a maxillary hybrid telescopic double crown denture with friction pin using remaining natural teeth as abutments. After 7 years, due to lack of recall check-up and poor oral hygiene, the abutment teeth were affected by periodontitis and 4 out of 5 of the abutment teeth had to be extracted. 3 additional implants were placed and the original abutment tooth with the inner crown was maintained. The mandible had fixed prostheses including implants but nevertheless, with strategic implant placement, the patient adapted well and was satisfied with the new maxillary tooth-implant combined double crown denture.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.2
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• pp.160-178
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• 2023

Diagnosis and analysis of occlusal relationships are important factors in prosthetic treatment. A thorough occlusion analysis and evaluation should be performed before treatment to restore a stable interocclusal relationship. Analysis and evaluation are essential during the treatment process and at regular follow-ups. Recently, with the development of dental equipment and digital processing methods, new quantitative analysis methods that can record the patient's occlusal relationship have been introduced. Among them, the T-Scan Novus (Tekscan Inc., S. Boston, MA, USA) displays the strength of the initial contact point and the occlusal contact point of the teeth using a pressure sensor. With this, occlusal contact time of the teeth, anteroposterior and left-right balance of occlusal force can be compared. The Dental prescale II (GC Co., Tokyo, Japan) scans the occlusal contact point using a pressure-sensing film and analyzes the density of the contact point. It can measure the distribution and strength of the occlusal force of the teeth in the most natural occlusion state. Based on this, appropriate prosthetic treatment (four-unit fixed partial denture, removable partial denture, complete denture, and complete oral restoration cases) was performed according to the area and extent of the patient's tooth loss. The patient's occlusion at the first visit, treatment stage, right after treatment, and regular follow-up were compared and evaluated using a quantitative method for appropriate occlusion analysis using T-Scan Novus and Dental prescale II. This report enhances the understanding of occlusion analysis during prosthetic restoration. The results satisfied both the clinician and patients in terms of function and aesthetics.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.2
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• pp.113-122
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• 2024

The gradual teeth wear with age is a natural phenomenon, but excessive wear beyond physiological levels can lead to vertical dimension loss, occlusal imbalance, temporomandibular joint disorders, and periodontal disease. In such cases, prosthodontic restoration becomes necessary emphasizing the importance of appropriate vertical dimension increase and stable occlusion in central relation (CR). In this case, a 74-year-old patient with clenching and grinding habit had severe teeth wear and after assessing interocclusal distance, wear degree, pronunciation, and facial profile, it was decided to perform full-mouth fixed prosthesis restoration with a 4 mm vertical dimension increase. And the significantly displaced Maximum Intercuspal Position (MICP) caused by parafunctional movements was re-established as a stable mutually protective occlusal relationship at centric relation and after a successful 4 months adaptation to provisional restorations, the final prosthesis was fabricated. During 4months of observation periods, stable occlusion in central relation and mutual protection occlusal relationships were maintained and the patient was satisfied with function and aesthetics, leading to this report.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.405-420
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• 2003

Purpose : The purpose of this study was to compare the fracture resistance of the IPS Empress ceramic crown with 1.0mm width rounded shoulder, which is usually recommended in all ceramic crown. and 0.5mm width chamfer finish lines on the maxillary central incisor. Material and method : After 15 metal dies were made for each group, the IPS Empress all ceramic crowns were fabricated and cemented with resin cement(Bistite resin cement, Tokuyama Soda Co. LTD., Japan) on the metal die. The cemented crowns were mounted on the positioning jig and the universal testing machine(Zwick Z020, Zwick Co. Germany)was used to measure the fracture strength with loading on the incisal edge. And also, three-dimensional finite element stress analysis was used to measure the stress distribution with the various types of the finish lines(1.0mm width rounded shoulder, 0.5mm width chamfer), the loading site(incisal edge, incisal $\frac{1}{3}$) and the type of loading(concentration loading, distribution loading). Results and conclusion : 1. In the fracture resistance experiment according to the finish line, the mean fracture strength of rounded shoulder(876N) and the mean fracture strength of chamfer(882N) did not skew any significant difference between each other(p>0.05). 2. The stress distribution of all ceramic crown in three dimensional finite element analysis showed concentration aspect at loading point and cervical area or labial surface. 3. In metal die, there were no differences in stress distribution between finish lines, but in natural teeth model, chamfer finish line showed higher stress than rounded shoulder finish line. 4. When force was loaded on the incisal edge the stress was concentrated on the incisal edge and the cervical area of labial surface. When force was loaded on the incisal $\frac{1}{3}$, the stress concentrated on the cervical area of labial surface and the cingulum area. 5. Generally, natural teeth model showed higher and various stress than the metal die.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.2
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• pp.258-272
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• 1998

This investigation evaluated patients who received Steri-Oss implants from the Dental Hospital of Chosun University during the period from March 1989 to August 1997. 346 fixtures of 127 patients were included in this study. The results were as follows ; 1.The follow-up period was defined as the period between the surgical placement of the implants and the last follow-up examination. The mean follow-up period was $2.17{\pm}1.21$ years. 2.The period between fixture installation and second surgery was $0.71{\pm}0.44$ years in the maxilla and $0.46{\pm}0.21$ years in the mandible. 3.The number of fixtures which were installed in the upper jaw(112) was less than that in the lower jaw(234) and in the posterior region(260) was more than in the anterior region(86). 4.The length of fixture which was most frequently used was 12 mm and least was 8mm. Screw implants were installed more than cylindrical implants. 3.8mm implant was the most common implans, followed by 4.5mm and 3.25mm. 5.The number of augmentation cases was more than that of non-augmentation cases and the rate of augmentation cases in the maxilla was more than that in the mandible. 6.Implant restorations for partial edentulos patients(94cases) were more than single- tooth implant restorations(33cases) or implant restorations for complete edentulos patients(10cases). 7.Free-standing prostheses for partially edentulous patients were more commom than any other type of connection between implants and natural teeth. 8.Plaque Index($0.95{\pm}0.74$) and Gingival Index($0.31{\pm}0.52$) were very similar around the natural teeth and reflected an acceptable level of plaque and gingivitis control. Mean value for keratinized mucosa index($1.93{\pm}1.20$) remained fairly constant around level 2(1-2 mm keratinized epithelium). 9.Patients were generally satisfied with implant in terms of comfort, function, speech and esthetics. 10.There was not a statistically significant differences in overall survial rate between implants placed in the maxilla (91.5%) and those placed in the mandible (93.8%). Fourteen implants lost before the prosthetic rehabilitation and eleven implants lost following variable periods in function after the prosthetic phase of the treatment. 11.Cause of implant failures was exfoliation or removal of fixture due to non-osseointegration before the prosthetic rehabilitation or due to fracture of fixture, masticatory pain after the prosthetic rehabilitation. 12.The survival rate of Steri-Oss implants using the Kaplan-Meier statistical analysis was 93.8% at 2 year and 86.6% at 5 year, In all cases, implant losses occured predominantly in the healing period. There was a steep decline in the rate of implant loss after the first year. 13.The survival rate of Steri-Oss implants in the anterior region was 94.8% at 2 year and 94.8% at 5 year and that in the posterior region was 92.8% at 2 year and 75.9% at 5 year. In conclusion, this study revealed a number of parameters and guidelines for achieving an optimal success rate in osseointegration.

• Journal of Technologic Dentistry
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• v.35 no.2
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• pp.145-155
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• 2013

Purpose: The recent proliferation of the aging population, oral health care is closely related to the mental health of the elderly is very important being recognized. Provide basic data for improving the quality of life for the elderly, to determine whether the oral health of the elderly whether oral self-perception of health and any related wish. Methods: Surveys to May 20 from April 15, 2011, subjects were elderly and living in Daejeon and Chungnam 277 people were examined. All the statistics using SPSS 18.0 for the determination of statistical significance, and the significance level was 0.05. Results: 1. Recognized, the most common oral health, self-aware bad the state (46.2%) there was no significant difference in the general characteristics according to self-Oral health status, remaining natural dimensions or the intra-oral prosthetic, there was no significant difference. More teeth, residual phase, in accordance with intra-oral prosthetic mandibular Not all dentures, partial dentures, full dentures net self-perception of oral health status better recognized. 2. According to the type of partial dentures, oral health status self-phase, mixed mandibular removable, fixed, fixed, removable partial dentures in order to recognize that good oral health, self-aware state, showed between them, there was no significant difference. 3. Of variable dimension that has nothing to do with the remaining natural maxillary and mandibular prosthetic maxillary prosthetic mandibular partial dentures, age income, a positive correlation was negatively correlated. The case of the mandible, the mandibular prosthetic mandibular partial denture, maxillary prosthetic, the amount of income were correlated. 4. Intra-oral Prosthetics correlation variables in the maxillary, mandibular prosthesis, the positive correlation between income, age was negatively correlated, if the income of the mandible. Maxillary partial denture has nothing to do with the variable portion of the mandibular denture, age was a negative correlation was found. Conclusion: Satisfaction and how now it is important simply to live as long, but you need to pay attention to the quality of life, sometimes with an aging population and the increase of soybean To buy the loss of teeth causes the typical health problems of the elderly. Elderly people of any relevant oral health and the oral cavity by the state to determine whether to provide the basic data for oral health education was more residual value, intra-oral prosthetics there is no more self-aware, the oral health status is good to recognize that appeared. Strengthen the oral health education to improve the quality of life of the elderly, and is thought to be necessary to increase the number of residual.

• Journal of dental hygiene science
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• v.4 no.3
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• pp.117-126
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• 2004

For a month of September, 2004, a questionnaire regarding dental hygiene was distributed to 165 workers of Ulsan area. A total of 125 questionnaire were analyzed: 102 collected of the distributed 165 pieces, and 23 questionnaires reported by patients of a dental clinic in Dong-gu, Woolsan. The result is as follows; (1) Labor workers of Ulsan have thought that they are in good dental health, 44.1% of respondents, following by those who they believe they are in moderate health and those who they think are in poor condition. 89.0% of total workers have experienced dental treatment. (2) Regarding the location of dental treatment, 85.0% of respondents have pointed out dental hospitals and clinics, while 3.9% have indicated that they had treatment from unlicensed dentists. Specifically, workers in their 40s over have ever experienced dental treatment by unlicensed dentists. Those who think they are in poor dental condition have tended to have more dental treatment by unlicensed dentists. (3) Regarding the reason that they put off the treatment, 59.1% of respondents have indicated that they have no time to have the treatment, following by economic burden and the lack of confidence in dentists. When they have tooth aches or the gum ache, 60% of respondents have suggested that they endure the ache or take a medicine to alleviate the pain, showing a lower understanding of early dental treatment. (4) Regarding the reason why they are unwilling to go to dentists, respondents have revealed the anxiety against pain, 50.4%, following by the difficulty of scheduling and unsatisfied services. (5) 47.2% of respondents have brushed their teeth 3 times everyday, following by those who have done it 2 times a day and those one a day. Regarding how to brush the teeth, most of respondents have brushed their teeth in the upper, lower, and the both side, 61.4%. The younger respondents and those who think they are in good dental health have tended to brush their teeth up and down. (6) Regarding the cause of the gum disease, 67.7% of respondents have thought that it is caused by poor dental hygiene, following by natural occurrence due to age, hereditary nature, and physical predisposition. (7) 67.7% of respondents have experienced dental scaling, while 32.3% of them have had no experience in it. 53.5% of workers have thought that scaling may not be recommended since they have the teeth scaled periodically once they had dental scaling, a higher rate than 46.5% who think scaling is good for the gum health.

• Korean Journal of Plant Taxonomy
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• v.35 no.1
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• pp.57-80
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• 2005

Morphological variation of Quercus L. subgen. Quercus in Korea was examined by numerical methods including principal components analysis of major morphological characters. Principal components analysis revealed the presence of five major species groups of the subgen. Quercus in Korea; these include 1) a group consisiting of Q. acutissima and Q. variabilis individuals, 2) Q. dentata, 3) Q. aliena, 4) Q. mongolica, and 5) Q. serrata. The putative interspecific hybrid individuals occupied intermediate position between the putative parent species in the PCA plot. The analysis also strongly suggested that size and shape of leaf blade and teeth or lobes, twig diameter, size and shape of nuts, and length and width of scales are very useful in distinguishing the species and the putative hybrids of the subgen. Quercus.