B-spline 법에의한 bruxism 환자의 교모소면 관한 연구

박해균,박상윤,신정일 朝鮮大學校 口腔生物學硏究所 1990 Oral Biology Research (Oral Biol Res) Vol.14 No.-

The purpose of this study was to obtain basic data by investigation the occlusal wear facets of the bruxism patients. A 25 year old subject with symptoms of burxism, was selected from patients in Chosun Dental Hospital. Five subjects, 25 years of age without symptoms of stomatognathic system were selected from dental stedents in infirmmary School of Deatistry, Chosun University. The area of occlusal wear facets was measured and divided into two group(Group I and GroupⅡ). A patient with bruxism is the Group I and the patients without bruxism are the Group Ⅱ. These two groups were investigated into maxillary and mandibular side wear facets. The results were as follows : 1. The average wear facet areas of all subjects were 121.313㎟, and Group I and Group Ⅱ were 177.073㎟ and 65.553㎟ respectively. 2. The right and left wear facet areas of Group Ⅰ were 74.406㎟ and 102.667㎟ respectively and the maxillary and mandibrula side wear facet areas of GroupⅠ were 97.102㎟ and 79.971㎟ respectively. 3. The right and left wear facet areas of Group Ⅱ were 27.034㎟ and 38.519㎟ respectively and the maxillary and mandibular side wear facet area of Group Ⅱ were 41.040㎟ and 24.513㎟.

터널 콘크리트 구조물의 내화설계 Approach 및 내화대책공법

박해균,이승복,이명섭,김재권 한국터널지하공간학회 2003 자연, 터널 그리고 지하공간 Vol.5 No.3

지대치 coping 형태에 따른 overdenture 하에서 하악 응력에 관한 유한요소법적 분석

박해균,정재헌 朝鮮大學校 口腔生物學硏究所 1991 Oral Biology Research (Oral Biol Res) Vol.15 No.-

This study was to analyze the displacemet and the magitude mode of distribution of the stresses in the lower overdenture, the mucous membrane, the abutment teeth and the mandibular supporting bone when various abutment designs were subjected to different loading schemes. For this study, the two-dimentional finite element method was used. The models of overdenture and mandibe with the canine and the second premolar remaining, were fabricated. In the first design, a 1 ㎜ space was prepared between the denture and the dome abutment with the height of 2 ㎜(OS). In the second design, a contect between the denture and the occlusal third of the dome abutment with the hight of 2 ㎜ was prepared(OC). In the third design, a 0.5 ㎜ sapce was prepared between the denture and 8 degree tapered cylindrical abutments with the height of 7 ㎜(TS). In the fourth design, a contact between the denture and the occlusal two thirds of the conical abutments with the height of 7 ㎜ was prepared(TC). In order to represent the same physiological condition as the fixed areas of the mandible under loading schemes, the eight nodes which lie at the mandibular angle, the coronoid process and the mandibular condyle were assumed to be fixed. Each model was loaded with a magnitude of 10 ㎏s on the first molar region (P1)and 7㎏s on the central incisor region (P2) in a vertical direction. The force of 1-㎏ was then applied distributively from the first premolar to the second molar of each model in a vertical direction (P3). The results were as follows: 1. The vertical load on the central incisor region(P2) produced the higher displacement and stress concentration than that on the posterior region(P1,P3). 2. The case of space between abutment and denture base produced higher displacement than that of contact, and the case of long abutment produced higher displacement than that of short abutment because of low rigidity of denture base. 3. The magnitude of the torque and vertical force to the abutment teeth and the stress distribution to the denture base was higher in the telescope coping than in the overdenture coping. 4. The vertical load on the central incisor region(P2) produced higher equivalent stress in the mandible than that on the posterior region(P1,P3). 5. The case of space between abutment and denture base produced better stress distribution to the farther from the loading point than that of contact. 6 In case of sound abutment teeth, the type of telescope coping can be used, but in case of weak abutment, the type of overdenture coping is considered to be favorable generally.

터널 화재에서의 콘크리트 내화대책

박해균,이승복,이명섭,김재권,Park, Hae-Gyun,Lee, Seung-Bok,Lee, Myeong-Seop,Kim, Jae-Gwon 한국방재학회 2003 한국도시방재학회지 Vol.3 No.2

한국인 자연치의 색에 관한 연구

박해균,정재헌,Park, Hae-Kyoon,Chung, Chae-Heon 대한치과보철학회 1988 대한치과보철학회지 Vol.26 No.1

The purpose of this investigation was to analyze the color of natural teeth by means of the OFC-1001 DP colorimeter which could measure in Adams Coordinate System (L,a,b system). The subjects were the 164 persons (82 men and 82 women) ranged from the teen to the sixtieth who had come to infirmary of dental college, Chosun University. The colors of incisal third, middle third and cervical third of maxillary right incisor, maxillary right canine and maxillary right second premolar were examined after the teeth were cleaned, polished and dried. The data were analyzed statistically by means of SPSS (Statistical Package For the Social Science). The results were as follows. 1. The means of L(lightness), a (red chromaticity), b (yellow chromaticity) of all teeth were measured (Table 2,3,4). 2. The color of teeth was yellowish-gray or bluish-gray. 3. The L value and b value of the cervical third was greater than those of the incisal and middle third. 4. The L value of maxillary 2nd premolar was greater than those of maxillary incisor md maxillay canine. 5. The a & b values of maxillary canine were greater than those of maxillary incisor and maxillary 2nd premolar. 6. The average values of L,a,b of teeth between male and female were not significant. 7. The L values of teeth were decreasing and the b values of teeth were increasing as the age was increased, but there was no corelation between the a values and aging.

지대치 coping형태에 따른 overdenture하에서 하악 응력에 관한 유한요소법적 분석

박해균,정재헌,조규종,Park Hae-Kyoon,Chung Chae-Heon,Cho Kyu-Zong 대한치과보철학회 1991 대한치과보철학회지 Vol.29 No.3

This study was to analyze the displacement and the magnitude and mode of distribution of the stresses in the lower overdenture, the mucous membrane, the abutment teeth and the mandibular supporting bone when various abutment designs were subjected to different loading schemes. For this study, the two-dimensional finite element method was used. The models of overdenture and mandibe with the canine and the second premolar remaining, were fabricated. In the first design, a 1 mm space was prepared between the denture and the dome abutment with the height of 2 mm(OS). In the second design, a contact between the denture and the occlusal third of the dome abutment with the hight of 2 mm was prepared(OC). In the third design, a 0.5 mm space was prepared between the denture and 8 degree tapered cylindrical abutments with the height of 7 mm(TS). In the fourth design, a contact between the denture and the occlusal two thirds of the conical abutments with the height of 7 mm was prepared(TC). In order to represent the same physiological condition as the fixed areas of the mandible under loading schemes, the eight nodes which lie at the mandibular angle, the coronoid process and the mandibular condyle were assumed to be fixed. Each model was loaded with a magnitude of 10 Kgs on the first molar region (P1) and 7 Kgs on the central incisor region (P2) in a vertical direction. The force of 10 Kgs was then applied distributively from the first premolar to the second molar of each motel in a vertical direction (P3). The results were as follows: 1. The vertical load on the central incisor region(P2) produced the higher displacement and stress concentration than that on the posterior region(P1, P3). 2. The case of space between abutment and denture base produced higher displacement than that of contact, and the case of long abutment produced higher displacement than that of short abutment because of low rigidity of denture base. 3. The magnitude of the torque and vertical force to the abutment teeth and the stress distribution to the denture base was higher in the telescope coping than in the overdenture coping. 4. The vertical load on the central incisor region(P2) produced higher equivalent stress in the mandible than that on the posterior region(P1, P3). 5. The case of space between abutment and denture base produced better stress distribution to the farther abutment from the loading point than that of contact. 6. In case of sound abutment teeth, the type of telescope coping can be used, hilt in case of weak abutment, the type of overdenture coping is considered to be favorable generally.

영구 숏크리트 터널 라이닝 구축을 위한 고성능 숏크리트 개발 (용수부에서의 조강시멘트와 alkali-free급결제 적용 검토)

박해균,이명섭,김재권 사단법인 한국터널지하공간학회 2003 한국터널지하공간학회논문집 Vol.5 No.1

Since the mid of 1990, permanent shotcrete tunnel linings such as Single-shell and NMT have been constructed in many countries for reducing the construction time and lowing construction costs instead of conventional in-situ concrete linings. Among essential technologies for successful application of permanent shotcrete linings, high performance shotcrete having high strength, high durability and better pumpability has to be developed in advance as an integral component. This paper presents the idea and first experimental attempts to increase early strength and bond strength of wet-mixed Steel Fiber Reinforced Shotcrete (SFRS) in spring water condition. In order to increase early behavior of SFRS, a new approach using high-early strength cement with alkali-free liquid accelerator has been investigated. From the test results, wet-mix SFRS with high-early strength cement and alkali-free accelerator exhibited excellent early compressive strength improvement compared to the ordinary portland cement and good bond strength even under spring water condition. 최근 NATM 터널 현장타설 콘크리트 라이닝의 시공성 향상과 균열에 따른 유지관리비 절감을 위해 양질 암반의 배수형 터널 시공에 있어서는 숏크리트만으로 라이닝을 대체하려는 영구지보 개념의 터널시공 (Single-Shell Tunnel, NMT 등)이 세계적으로 증가하고 있는 추세이다. 이러한 영구지보 개념의 터널 시공을 위해서는 고성능 숏크리트의 개발이 선결되어야 하며, 이러한 목적에서 본 논문에서는 조강시멘트와 최근 주목받고 있는 환경친화적인 alkali-free 급결제의 조합을 통해 고성능 숏크리트의 개발 가능성을 확인하였다. 그 결과, 보통시멘트(OPC)를 사용한 숏크리트보다 약 25%의 높은 초기강도를 확보하였으며, 용수부에서도 뛰어난 부착특성을 확인할 수 있었다.

의치상 레진에 관한 임상적 고찰

박해균,나경선 朝鮮大學校 口腔生物學硏究所 1990 Oral Biology Research (Oral Biol Res) Vol.14 No.-

The next and most recent milestone in the denture base field was the introduction of acrylic resin to the dental profession in 1936. It is estimated that 99% of all complete denture are fabricated with one of the acrylic resins. Most acrylic resin denture bases produced currently are made from polymethyl methacrylate, which is a polymer consisting of structural mer units derived from methyl methacrylate. Most modern acrylic resins contain a cross-linking agent in the monomer (such as glycol dimethacrylate), which provides resistance to crazing. The advantages of the acrylic resins are 1) excellent esthetics 2) easy and simple to mold and press 3) easy to repair, reline, rebase and adjust 4) dimensionally accurate and stable (processing change is usually less than 0.5% or 0.2㎜) 5) inexpensive and adequate strengh in most situations, barring sudden impact etc. However, the disadvantages are 1) poor thermal conductor 2) nonwettable surface may decrease possible retention, food may cling to surface 3) relatively low modulus of elasticity and high coefficient of thermal expansion etc. All acrylic resin denture baes contain 0.2 to 0.5% residual monomer after processing. It is difficult to see any connection between denture sore mouth and residual monomer. Practially all denture sore mouths are caused by trauma. Allergy to acrylic resin denture base materials is very rare. The physical and mechanical properies of denture base materials do not decline on aging. Serviceability of dentures, however, is often lessened by resorptive changes of the osseous alveolar processes. These changes cause a gradual deterioration in centric and eccentric occlusion and a decrease in face height. The purpose of this study was to investigate the kinds, characteristics, changes and biological properties of acrylic resin denture base material.

신개념의 도심지 장대 지하차도 설계

박해균,조형제,심성현,심재범,Park, Hae-Gyun,Jo, Hyeong-Je,Sim, Seong-Hyeon,Sim, Jae-Beom 한국터널지하공간학회 2008 자연, 터널 그리고 지하공간 Vol.10 No.2

저비용.고효율 고성능 콘크리트(HPC) 교면포장 공법

박해균,김지원,원종필,이명섭,Park, Hae-Gyun,Kim, Ji-Won,Won, Jong-Pil,Lee, Myeong-Seop 한국시멘트협회 2006 시멘트 Vol.173 No.-