• 제목/요약/키워드: natural tooth form

검색결과 21건 처리시간 0.029초

치과 임플랜트 보철 장착자의 구강 감각 기능에 관한 연구 (A STUDY ON ORAL SENSORY FUNCTION IN THE IMPLANT-SUPPORTED PROSTHESES WEARERS)

  • 장경수;김영수
    • 대한치과보철학회지
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    • 제29권1호
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    • pp.215-232
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    • 1991
  • In this study, oral sensory function in the osseointegrated root form implant-supported prostheses wearers was estimated by measuring occlusal tactile perception threshold of thickness and sensibility threshold against lateral static loading, and comparing with normal dentition subjects and complete denture wearers group. Osseointegrated root form implants seemed to be restored in the sensation to some extent, and so, dental implants restored edentulous patients in a wide meaning. Conclusions were summarized as following. 1. Occlusal tactile perception threshold of thickness was highest in complete denture wearers group, following by implant-supported prostheses wearers group, normal dentition subjects group. 2. In the implant-supported prostheses wearers group, occlusal tactile perception threshold of opposing artificial teeth case was higher than of opposing natural or opposing implantsupported teeth case. 3. Sensibility threshold against lateral loading of complete denture wearers and implantsupported prostheses wearers group was higher than that of normal dentition subject group. 4. In the implant-supported prostheses group, sensibility threshold against lateral loading was not significantly different between upper and lower jaws. 5. In occlusal tactile perception threshold of thickness and sensibility threshold against lateral loading test, there was no regularity among values of each tooth, and no significant difference between anterior and posterior teeth as well.

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Digital Shade Analysis System을 이용한 전치부의 색조 특성에 관한 연구 (SHADE ANALYSIS OF ANTERIOR TEETH USING DIGITAL SHADE ANALYSIS SYSTEM)

  • 김희은;조인호;임주환;임헌송
    • 대한치과보철학회지
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    • 제41권5호
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    • pp.565-581
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    • 2003
  • Statement of problem : A scientific examination and understanding of overall aspects of the natural dentition is the first step involved in making a satisfactory selection in the shade of an aesthetic prosthesis. Proper natural shade selection of the prosthetic restoration that is in harmony with the remaining dentition is as important aesthetically, as harmony of form and function in the anterior dentition. Clinically, the most commonly applied method of shade selection has been visual, but because of the subjective nature inherent to this method, shade selection results are variable and can be influenced by such factors as the technician, the type of shade guide used, and the type and intensity of the lighting. Purpose : The purpose of this study was to develop a more objective and scientific approach to examining and understanding the shade of teeth, which has in turn lead to the development of a number of shade analysis devices that present a more objective method of shade analysis. Material and Method : In this study, the shades of healthy anterior teeth were examined and analyzed using the recently developed digital shade analysis of the $ShadeScan^{TM}$ System. The study examined 80 individuals in their twenties, 40 males and 40 females, presenting 6 healthy, unrestored maxillary anterior teeth. Tooth brushing and oral prophylaxis were performed prior to evaluation. The ShadeScan handpiece was used to acquire images of the 6 maxillary anterior teeth. These images were analyzed using the Vita/Classical mode of the $ShadeScan^{TM}$ Software, and shade maps of each tooth were acquired and divided into cervical, middle, and incisal thirds. The shade distribution of each third, left and right symmetry, and gender differences were investigated and analyzed. Results : The results of the study are as follows : 1. An overwhelming majority of the examined teeth were found to possess shades belong to Group A, with the greatest variations occurring at the middle and cervical thirds of the maxillary central and lateral incisors, in both male and female subjects. 2. Canines of both male and female subjects showed left and right symmetry with uniform shade distribution of A4 and C4, while the lateral and central incisors showed left-right symmetry of the incisal 1/3 with a uniform shade distribution of A2 and A3 shades 3. No significant differences in shade distribution were seen between genders in maxillary canines, whereas maxillary central and lateral incisors showed differences at the middle and cervical thirds between male and female subjects The results of this study show that with the exception of maxillary canines, maxillary anterior teeth display a diverse shade distribution as well as gender differences. Conclusion : Clinically, when making a shade selection using the existing shade guide, one must consider the fact that even a single tooth consists of a variety of shades. The results of this study show that when selecting a shade from a number of groups is difficult, shades from A group are the most consistent with the natural shade or maxillary anterior teeth.

근관치료의 시작 - 치수강 개방 (First step of root canal therapy-access cavity preparation)

  • 송민주
    • 대한치과의사협회지
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    • 제56권10호
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    • pp.572-580
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    • 2018
  • Adequate access cavity is the key to achieving endodontic success. The aims of the access cavity can be considered as follows: 1) Creation of a smooth unimpeded pathway for instruments to canal orifices 2) Removal of the entire roof of the pulp chamber in order to inspect the pulp floor, 3) Preservation of natural tooth substance consistent with the above. Recently, contracted endodontic cavities based on minimally invasive endodontics has introduced. This has the benefit of preserving the pericervical dentin more than traditional access cavity with achieving long-term success. However, some studies reported controversial results regarding root canal detection, instrumentation efficacy (noninstrumented canal area, hard tissue debris accumulation, canal transportation, and centering ratio) as well as fracture resistance. Therefore, further studies are required for accepting contracted access cavity, and modified form of traditional and contracted access cavity could be considered.

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인접치아가 임플란트 치은연하 세균총의 분포에 미치는 영향 (The influence of adjacent tooth to the microbiology of implant sulcus)

  • 이동영;이만섭;권영혁;박준봉;허익;정종혁
    • Journal of Periodontal and Implant Science
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    • 제35권3호
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    • pp.563-575
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    • 2005
  • The aim of present study is to evaluate the influence of adjacent tooth to the microbiology of clinically healthy implant. Control group included patients who had clinically healthy implant and tooth with healthy $periodontium(PD{\leq}3mm)$, test group was composed of patients who had clinically healthy implant and tooth with periodontal pocket(PD>3mm). The criteria of clinically health implant are no pain or discomfort, the restorative suprastructure provide satisfactory fit and function, and the tissue around the fixtures were firm and probing with standard periodontal probe with a rounded tip 0.5mm in diameter resulted in penetration of no more than 5mm when using a force of 0.5N at any location. 38 patients, partially edentulous subjects with endosseous root-form implants were selected. All subjects were medically healthy and had not taken systemic antibiotics and professional plaque control 3 months before sampling. Number of control group is 25(mean age $52{\pm}13$, 26 teeth, 34 implants) and test group is 13(mean age $60{\pm}13$, 13 teeth, 17 implants). All teeth and implants of each patient were examined probing depth(PD), bleeding on probing(BOP), and plaque index(PI), and samples of subgingival plaque were obtained at each site with sterile curet or fine paper points, then the plaque transferred to PBS. Obtained samples were examined for the presence of P. gingivalis, T. forsythensis, and T. denticola by the polymerase chain reaction(PCR). The relationship among clinical parameters and the colonizations by the 3 bacterial species from natural teeth and implants region were analyzed by student t-test. The results of this study were as follows: 1. PD was different in teeth between 2 groups(p<0.05), but the other parameters were not. 2. Statistically significant difference was not found in clinical parameters of implants between 2 groups. 3. All bacterial prevalences of teeth were higher in test group than in control group, and prevalence of T. forsythensis had statistically significant difference between 2 groups(p<0.05). 4. Prevalences of P. gingivalis and T. forsythensis are higher in test group than control group, and that of T. denticola is higher in control group than in test group. But there were no statistically significant differences between 2 groups. In conclusion, there is no statistically significant difference in prevalence of implant microbiology between 2 groups. But if the number of samples increased, it will be possible to find out statistical significance in prevalence of P. gingivalis. It seems that pocket of adjacent tooth influences prevalence of P. gingivalis. These results mean that improvement of the periodontal condition before implantation is very important.

보철학적 교합 재구성을 위한 교합진단과 치료계획 (The Occlusal Evaluation and Treatment Planning for Prosthodontic Full Mouth Rehabilitation)

  • 이승규;이성복;최대균
    • 구강회복응용과학지
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    • 제16권2호
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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.

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해외 자생식물추출물이 Streptococcus mutans의 세포 성장 및 생물막 형성에 미치는 영향 (Effects of Foreign Plant Extracts on Cell Growth and Biofilm Formation of Streptococcus Mutans)

  • 문경훈;이윤채;김정남
    • 생명과학회지
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    • 제29권6호
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    • pp.712-723
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    • 2019
  • 화학적으로 합성된 물질들이 주로 구강 위생 제품에 사용된다. 그러나 이러한 화학 물질을 장기간 사용 시, 내성 발생이나 알레르기, 치아변색과 같은 부작용이 발생할 수 있다. 이런 문제를 해결하기 위해 식물로부터 유래된 항균 물질의 사용과 이러한 항균 물질들의 탐색을 위한 노력이 계속 진행되고 있다. 본 연구를 통해 Streptococcus mutans의 성장과 생물막 형성을 저해하는 해외 자생식물을 탐색하고자 하였다. 본 실험에는 총 300종의 해외 자생식물 추출물이 사용되었으며, 그 중 Chesneya nubigena (D. Don) Ali 추출물이 S. mutans에 대한 비교적 높은 항균활성을 나타내는 것으로 확인되었다(clear zone, 9 mm; MBC, 1.5 mg/ml). 또한, 19종의 식물추출물이 농도에 비례적으로 S. mutans의 생물막 형성량을 최소 6배 이상 감소시키는 것을 확인하였다. 특히, C. nubigena (D. Don) Ali 추출물은 1.25 mg/ml의 낮은 농도에서부터 효과적으로 생물막 형성을 억제하는 것으로 관찰하였다. 본 연구를 통하여 C. nubigena (D. Don) Ali 추출물이 S. mutans의 생육 성장과 생물막 형성 저해 효과를 나타내었으며, 이를 통해 본 식물추출물이 충치 예방과 치료에 효과가 있는 항균 대체재 개발의 후보 소재로써 평가된다.

Epigallocatechin-3-gallate prior to composite resin in abfraction lesions: a split-mouth randomized clinical trial

  • Luisa Valente Gotardo Lara Alves;Lisiane Martins Fracasso;Thiago Vinicius Cortez;Aline Evangelista Souza-Gabriel;Silmara Aparecida Milori Corona
    • Restorative Dentistry and Endodontics
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    • 제48권2호
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    • pp.13.1-13.11
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    • 2023
  • Objectives: Natural extracts have been investigated as a biomimetic strategy to mechanically strengthen the collagen network and control the biodegradation of extracellular matrix. This study evaluated the effect of epigallocatechin-3-gallate (EGCG) on abfraction lesions prior to the composite resin. Materials and Methods: The sample consisted of 30 patients (aged between 28 and 60 years) with abfraction lesions located in 2 homologous premolars. The teeth were randomly assigned according to dentin treatment: 0.02% EGCG solution or distilled water (control). After enamel acid etching, the solutions were applied immediately for 1 minute. The teeth were restored with Universal Adhesive (3M) and Filtek Z350 XT (3M). Analyzes were done by 2 independent examiners using modified USPHS (retention, secondary caries, marginal adaptation, and postoperative sensitivity) and photographic (color, marginal pigmentation, and anatomical form) criteria at baseline (7 days) and final (18 months). The data analysis used Friedman and Wilcoxon signed-rank tests (α = 0.05). Results: At baseline, all restorations were evaluated as alpha for all criteria. After 18 months, restorations were evaluated as alpha for secondary caries, color, and marginal pigmentation. There was significant difference between baseline and 18 months (p = 0.009) for marginal adaptation and postoperative sensitivity (p = 0.029), but no significant difference were verified between treatments (p = 0.433). The EGCG group had a restoration retention rate of 93.3%, while the control group had 96.7%. Conclusions: The application of EGCG solution on abfraction lesions did not significantly influence the survival of the restorations based on clinical and photographic criteria.

Effect of seeding using an avidin-biotin binding system on the attachment of periodontal ligament fibroblasts to nanohydroxyapatite scaffolds: three-dimensional culture

  • Jang, Yong-Ju;Jung, Im-Hee;Park, Jung-Chul;Jung, Ui-Won;Kim, Chang-Sung;Lee, Yong-Keun;Kim, Chong-Kwan;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • 제41권2호
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    • pp.73-78
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    • 2011
  • Purpose: For periodontal tissue engineering, it is a primary requisite and a challenge to select the optimum types of cells, properties of scaffold, and growth factor combination to reconstruct a specific tissue in its natural form and with the appropriate function. Owing to fundamental disadvantages associated with using a two-dimensional substrate, several methods of seeding cells into three-dimensional scaffolds have been reported and the authors have asserted its usefulness and effectiveness. In this study, we explore the cell attachment of periodontal ligament fibroblasts on nanohydroxyapatite (n-HA) scaffold using avidin biotin binding system (ABBS). Methods: Human periodontal ligament fibroblasts were isolated from the health tooth extracted for the purpose of orthodontic procedure. HA nanoparticles were prepared and $Ca(NO_3)_2-_4H_2O$ and $(OC_2H_5)_3P$ were selected as precursors of HA sol. The final scaffold was 8 mm in diameter and 3 mm in height disk with porosity value of 81.55%. $1{\times}10^5$ periodontal ligament fibroblasts were applied to each scaffold. The cells were seeded into scaffolds by static, agitating and ABBS seeding method. Results: The number of periodontal ligament fibroblasts attached was greater for ABBS seeding method than for static or agitating method (P<0.05). No meaningful difference has been observed among seeding methods with scanning electron microscopy images. However, increased strength of cell attachment of ABBS could be deduced from the high affinity between avidin and biotin ($Kd=10^{-15}\;M$). Conclusions: The high-affinity ABBS enhances the ability of periodontal ligament fibroblasts to attach to three-dimensionally constructed n-HA scaffold.

ITI $TE^{(R)}$ 임플란트의 생존율에 관한 후향적 임상 연구 (A retrospective clinical study of survival rate of the ITI $TE^{(R)}$ implant)

  • 서현기;채경준;정의원;김창성;조규성;최성호;채중규;김종관
    • Journal of Periodontal and Implant Science
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    • 제36권3호
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    • pp.673-682
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    • 2006
  • Recent study shows that implant design has a great impact on initial stability in bone. The ITI $TE^{(R)}$ implant, designed originally for immediate placement has a tapered/ cylindrical form which fits the anatomical shape of the natural alvelous or tooth root. The increased diameter at the collar region coupled with more threads lead to more bone contact and enhanced stability. The aim of this retrospective study is to evaluate the clinical use and the efficacy of recently introduced ITI TE implant with a new macro-design. The following results are compiled from 139 patients who received ITl TE implant surgery at the periodontal department. of Yonsei University Hospital between July 2002 and September 2005. 1. 139 patients received 173 ITl $TE^{(R)}$ implants in their maxilla and mandible (Mx 82, Mn 91). Posterior area accounted for 84% of the whole implant surgery, 2. In the distribution of bone quality, type III(41,0%) was the most, followed by type IV(41,0%) and type II (27.7%). As for the bone quantity, type B(43.9%) was the most, followed by type C(42.2%), type D(12.2%) and type A(1.7%). 3. 125 implants(83.9%) were treated by single crown, which accounted for the majority. 4, The total implant survival rate was 100% after a mean follow-up period of 21.2 months. This preliminary data with ITl $TE^{(R)}$ implant showed excellent survival rate although the majority of implants evaluated in this study were placed in the posterior region of the jaw and compromised sites.

한국.중국.일본 여성의 색조대장문화 (A Study on Make-up Culture of Korea, China and Japan)

  • 박보영;황춘섭
    • 복식
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    • 제39권
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    • pp.217-237
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    • 1998
  • The present research is to study the make-up culture of Korea and its neighboring countries such as China and Japan during the period from the prehistoric age to the 19th cen-tury. The research was made by documents analysis. The results are summerised as follows : (1) A man has a basic instinct to beautify himself. There was not a significant difference between the make-up behavior of men and women in its primal stage. It was by the start of farming and the division of labor that made the make-up behavior as a feminine culture. The difference of sexual role caused the con-ceptual difference between manly beauty and womanly beauty. It was very natural for women to regard the make-up as the best way for showing their feminine beauty. In Korea, China and Japan, there were vari-ous kinds of primal actions such as tattooing, body-painting, and tooth make-up which were used in the purpose of body protection, incantation, ornament, and so on. Ass their ornamental purpose was becoming more important, these primal actions became the basis of the feminine make-up culture. Nowadays make-up, having mental and emo-tional function, is helpful to increasing self-satisfaction, promoting good personal relation-ship, and attracting attention from the other sex. It also has other functions of showing social status, wealth, age, sex, courage, power, and so on. (2) The representative make-up product used widely in the three countries was Boon (powder) which decides the overall color of face. The key point in the production of Boon was to increase its power of adsorption. The invention of Yunboon (power mixed with lead) solved this major problem of Boon. Yeonji which decides the color of cheek was the mixture of Boon and the powder of Honghwa (a kind of red-colored flower or tree). Mimook (eyebrow pencil) was developed to match up with the various and changing currencies of penciling eyebrows in each nation and times, Yeonji and Joosa (red sand) were used as Jinji (lip stick). The predominant color of Jinji was red. As miscellaneous methods of partial make-up, there were Kon-ji used in a wedding cer-emony in korea, Aek-hwang, Hwa-jeon, Sa-hong, and Myun-yup in China, and Chi-heuk, a peculial method of partial make-up in japan. (3) There were various factors which decided the characteristics of make-up culture usually reflects international atmosphere, the form of government, economic situation, re-ligious and social ideology, aesthetic sense, symbolizing meanings of colors, and so on. The up and down of an influentian country was one of the major factors which decided the characteristics of the make-up culture of its neighboring countries. When a country took a liberal form of government, it had diverse and splendid tendencies in its make-up culture. The better a nation's economic situation is, the more abandant and various its make-up culture is, and sometimes, the more eccentric and decadents it was. In the field of make-up production, the three countries had their own characteristics. But, as a whole, China was the leading nation who spread the culture and products of make-up to Korea and Japan. Though the Chinese make-up culture and products were usually spread to Japan through Korean, there was some evidence of direct exchanges between China and Japan through its dispatches of Kyun-Tang-Sa(Japanese delegation to the Tang Dynasty). While religion had a positive influence on the development of make-up culture by introducing new methods of make-up, Confucianism exercised strict control over the make-up cul-ture. The currencies in arts and changes of esthetic sense introduced new methods and booms to the make-up culture. Literature made people pay increasing attentions to the countenances of women and changed the standards of esthetic sense. We can find out that the social status of woman was also reflected in the make-up culture. As the social status of women became higher, the feminine make-up culture also developed more then ever. As mentioned above, the make-up cultures of the three countries reflected their social values, esthetic senses, and emotional feelings. Through their cultural exchanges, the three countries could develop various make-up products and methods.

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