• 제목/요약/키워드: Canal surface

검색결과 194건 처리시간 0.02초

치근단절제시 노출된 상아세관의 밀폐효과에 대한 Nd : YAG 레이저의 효과 (THE EFFECT OF ND : YAG LASER ON DENTINAL TUBULE SEAL AFTER ROOT END RESECTION)

  • 신광철;홍찬의
    • Restorative Dentistry and Endodontics
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    • 제21권1호
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    • pp.311-320
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    • 1996
  • If root and resection is done during surgical endodontic treatment, newly exposed dentinal tubules form pathways between the canal and the peripheral tissue. Nd : YAG laser was used to block this phenomenon, and its effect was studied with dye penetration and SEM techniques. 40 intact single rooted teeth were divided into 4 groups(10 each) : control group and test groups, in which retrograde cavity surface, cutting surface, retrograde cavity surface & cutting surface were treated with laser(1 watt 15pps) and finally retrograde filling with IRM was conducted. After that, they were stained with 2 % methylene blue, sectioned and evaluated by the maximum infiltration depth. And to observe surface change, they were prepared for SEM. The results were as follows ; 1. All experimental groups showed microleakage with variation in amount. 2. The 2nd group which treated both the retrograde cavity and cutting surface showed significantly less microleakage than the other groups(p<0.05). There was no significant difference between groups treated on one side only. 3. As a result of SEM observation of dentin surface, obstruction of dentinal tubules with marble shaped granules, which were different from normal dentin could be seen. Cracks could be seen also. 4. In summary of this experiment, it is thought that effort to obstruct the exposed dentinal tubules as well as retrograde cavity after root end resection is needed.

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양식산 경골어류 3종의 난문과 방사대의 미세구조 (Ultrastructure of Egg Micropyles and Zona Radiata in Three Aquacultural Teleosts)

  • 윤종만
    • 한국어류학회지
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    • 제11권2호
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    • pp.126-133
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    • 1999
  • 무지개송어 (Oncorhynchus mykiss), 메기 (Silurus asotus) 그리고 미꾸리 (Misgurnus anguillicaudatus)의 성숙 난자의 방사대 (zona radiata) 및 난문의 미세구조적 특징을 광학, 주사 및 투과 전자현미경을 이용하여 조사하였다. 무지개송어와 메기의 난에 있는 난문은 깔대기 형태의 전정과 방사대를 통과하는 끝이 작아지는 통로로 구성되어 있었다. 무지개송어와 메기의 난문은 편평한 구멍과 긴 통로로 구성된 구조를 나타내었다. 메기 난문의 구조는 무지개송어 난문의 구조와 일치되었다. 무지개송어의 난문을 구성하는 내부 벽은 시계방향(우선형)의 구조를 나타내었다. 미꾸리의 난문은 짧은 통로를 지닌 얕은 구멍을 가진 형태를 나타내었고, 시계방향의 반대방향으로 난문의 벽은 방향성율 나타내었다. 미꾸리의 이러한 나선형의 방향은 무지개송어의 방향과 일치하지 않는 것으로 나타내었다. 개구부 바로 주변부에 있는 표면은 실험에 이용된 3가지 어류에서 모두 여러 가지 크기의 작은 구멍이 존재하였다. 상호 연결부위 (ridge)가 모든 어류의 미수정된 난자에서 관찰되었다. 본 논문에서는 난성숙시 난막과 난문의 형태를 알아보기 위해서 3가지 양식어종 난자의 표면형태와 난문의 미세구조를 상호 비교하였다.

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닭 부고환부(副睾丸部)의 각종(各種) 관상피(管上皮)의 형태(形態) 및 흡수(吸收)에 관한 연구(硏究) (Morphological and Absorptive Studies on Canal Epithelium of the Various Ducts in Rooster Epididymal Region)

  • 이재홍
    • 대한수의학회지
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    • 제14권2호
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    • pp.159-171
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    • 1974
  • Histological and histochemical studies were made on the lining epithelia of the various ducts in epidymis of the Rooster and absorptive function of the canal epithelial cells in the Rooster epididymis were also investigated after administration of India ink. The results obtained were summerized as follows; 1. Epihtelium lining the rate testis was mainaly composed of single later of cuboidal cells, and was partially composed of flattened squamous or low columnar cells. Efferential ductules were characterized by having many villous projections orrfolds which extened into the lumen, and were lined by stereociliated pseudostratified epithelium which consisted of manily ciliated columnar cells, a few scattered clear cells and basal cells. Connecting ductules were lined by ciliated pseudostriatified colummnar epithelium in which ciliated columnar cells, clear cells and basal cells were noted. Epididymal ducts were lined by pseudostratified epidhelium in which columnar and basal cells were noted. 2. PAS-granules, saliva resistant were noted mainly in the epithelial cells of efferential and connecting ductules. 3. Sudan black B stained heavily the granules in the epithelial cells of sufferential and connecting ductules. 4. The granules reactive to acid phosphatase most abundant in the epithelial cells of efferential ductules and were lesser amount in the epithelial cells of connecting ductules where as very few or no granules were seen in the rest of the ducts. 5. Alkaline phosphatase activity was most prominent but discontinuous in the luminal surface of the epithelium of efferential ductules and less marked in the connecting ductless. No enzyme activity was noted in the canal epithelium of epididyml duct. 6. India ink granules were most numerous in the epithlial cells of efferential ductules and were a few in connecting ductules. Very few or no granules of India ink were noted in the other types of the ducts. India ink granules in the epithelium increased gradually as the time after the administration of India ink (one up to twenty-nine hours) has proceeded. From those results it is suggested that epithelial cells of efferential and connecting ductules have active absorptive function, whereas the rest of duct system in the epididymis of the Rooster may be the mere pathway of the seminal fluid without significant modification of its constituents.

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상아질과 Gutta-Percha에 대한 근관충전용 Sealer의 결합강도의 측정 (MEASUREMENT OF ADHESION OF ROOT CANAL SEALER TO DENTINE AND GUTTA-PERCHA)

  • 허미자;유미경;이세준;이광원
    • Restorative Dentistry and Endodontics
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    • 제28권1호
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    • pp.89-99
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    • 2003
  • The purpose of this study was to investigate the bonding of resin- based root canal sealer, AH26 when the sealer was applied as a thin layer between dentine and gutta-percha surface. In this study forty non-caries extracted human molars and resin-based root canal sealer(AH 26, DeTrey/Dentsply, Germany) were used. Disks of gutta-percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for thermoplastic obturation were used and dentin surfaces were treated with 2% NaOCl(Group 1) or 2%NaOCl+17% EDTA(Group 3). Disks of gutta-Percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for conventional obturation were used and dentin surface were treated with 2% NaOCl(Group 2) or 2%NaOCl+17% EDTA(Group 4). Enamel was removed by a horizontal section 1mm below the deepest portion of the central occlusal groove by using a watercooled low speed diamond saw. A second horizontal section was done around cementoenamel junction. Exposed dentin surface was cut to approximately $8{\times}8{\;}mm$ rectangular shape and was ground against 320, 400, 600 grade silicon carbide abrasive paper serially. After grinding, the dentine surface were soaked in a solution of 2% NaOCl for 30 minutes and twenty of specimens were treated with 17% EDTA solution for 1 minute. The treated specimens were washed and dried, Root canal sealer, AH26 was prepared according to the manufacture's instructions The Gutta-percha and dentin surface were coated with a thin layer of the freshly mixed seal or. The specimens were left overnight at room temperature. After their initial set, they were transferred to an incubator at $37$^{\circ}C$ for 72 h. After 72 hours, resin blocks were made. The resin block was serially sectioned vertically into stick of $1{\cdot}1mm$. Twenty sticks were prepared from each group. After that, tensile bond strength f3r each stick was measured with Microtensile Tester Failure patterns of the specimens at the interface between gutta-percha and dentin were observed under the SEM(x1000) and Stereomicroscope (LEICA M42O, Meyer Inst., TX U.S.A) at 1.25 x25 magnification. The results were statistically analysed by using a One-way ANOVA and Tukey's test. The results were as follows; 1. Tensile bond strengths($mean{\pm}SD$) were expressed with ascending order as follows: Group 1, $3.09{\pm}$ 1.05Mpa : Group 2, $6.23{\pm}1.16MPa$ : Group 3, $7.12{\pm}1.07MPa$ : Group 4, $10.32{\pm}2.06MPa$. 2. Tensile bond strengths of the group 2 and 4 used disks of gutta-percha for conventional obturation were significantly higher than that of the group 1 and 3 used fir thermoplastic obturation. (p < 0.05). 3. Tensile bond strengths of the group 3 and 4 treated with 2% NaOC1+17% EDTA were significantly higher than that of the group 1 and 2 treated with 2% NaOCl. (p < 0.05). 4. In analysis of failure patterns at the interface between sealer and gutta-percha, there were observed 49 (61%)cases of adhesive failure patterns and 31 (39%) cases of mixed failures patterns.

기계화를 전제로 한 산간경사지답경지정리방안에 관한 연구(II) (A Study on the Methodology of Land-Consolidation Sloping Paddies in land Vallry for the Farm-Mechanization (II))

  • 황은
    • 한국농공학회지
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    • 제24권4호
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    • pp.57-68
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    • 1982
  • The paddy fiels slope located in Kangweon province Hwyongsung gun Gonggeun myon Shinchonri was considerably steep and so it was impossible to economically consolidate the field up to date. But for the porpose of farm mechanization, the field (32. 27ha) was consolidated by the auther under the assitance of the Ministry of Agriculture and Fishery and,;the Administration of Kangweon province. This paddy field consolidation was caused by the treatise on "Land-consolidation methods for farm mechanization in the steep-sloped paddy field", of which the auther is the same. The constrution was carried out from September, 1981 to April, 1982. During the 4esign and construction, some Peculiarities were found and discussed. That is, in design, besides the common condititions for a design, some special conditions were considered and written below; (1) The ranges of field slope in this design were 1/100-1/30. (2) Long sides of the land readjustment blocks must be arranged abreast contour line, and so they make the amount of cutting and banking decreased so as to take the maximum advantage of the configuration of the field. (3) In design, the main principles of dividing blocks were written below; i) First of all, long side of a block should be drawn straight abreast a contour line. ii) Long side of a block should arrange abreast contour line and make its length 100-150m, if not, l)reak the side in order to make a bended rectangle. iii) Length of a short side should be determinded within differences of elevation (0.6 -1. 2m) between the two adjacent blocks toward the normal to a contour line. iv) Length of a short side should be above 15m and the ratio of long and short side should be slso kept 1: (4-6). v) A new field surface leveling was determinded from the elevation which produce the least amount of cuttingand banking within the range of 0.6-1. 2m diffe rences of elevation between the two adjacent blocks. vi) In the course of dividing blocks with the same width along the line which was normal to a contour line, all blocks connot keep their shape in a retangle because of steep slope of the field and so on, and so it was also necessory to make some non-retanglar and small blocks such as a trianglar or trapezoidal shape, which was impossible to use some of farm machinery. But because this non-rectanglar and small blocks were divided, larger and many rectanglar blocks can be divided and construction cost can also be lowered. According to the conditions discussed above, the paddy field consolidation project designed and constructed. And the results of this study were obtained as below; (1) Three-forth of total cost of this paddy field consolidation was not construction cost, and these cost consist of land grading (1/4), road and canal construction cost (1/4) and the other cost (1/4) such as surveying or materials and 56 on. (2) The steeper the land slope, the greater cost was assigned for road and canal construction, and than land grading. (3) Curtailment of the road and canal construction cost depended on simplificating their strutures. (4) In the case of the land slopes were low, the land grading cost was high by 1: 1.4 in comparison with the road and canal construction cost, and conversely when the slops were steep, the road and canal construction cost was high by 1 : 5 in compa- rison with the land grading cost. (5) The densities of irrigation canal, drainage canal and trunk and branch road were 150. Sm/ha, 60. im/ha and 17. 4m/ha respectively. The density of irrigation canal of the area was high by 2 times in comparison with the average one of Kangweon Province, and the others were nearly the same. (6) Most farmers (above 85%) knew the effects of paddy field consolidation. The effects are; 1) Improvement of irrigation 2) Improvement of farm management 3) Improvement of transportarion 4) farm mechanization and 5) grouping of the scattered land. And the more farm modernization was accomplished by these projects, the more farmers wanted to live in their land. (7) In spite of the very steep sloped paddy field, the diminution rate of the net farm land caused by consolidation was 7.7% which was nearly the same as the one of Chulweon plain of Kangweon province. Land grading cost was 971, OOOwon/ha which was rather cheap by 13.2% than the one of Ghulweon plain, and unit construction cost was 5, 341, OOOwon/ha (included soil addition) which was also nearly the same as the one of Chulweon plain and FNFIA (The federation of national farmland improvement association).

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소규모 농업용 저수지의 통관 방류량 및 수질 측정 (Monitoring of Outlet Discharge and Water Quality from a Small Agricultural Reservoir)

  • 최진규;손재권;구자웅;윤광식;김영주
    • 농촌계획
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    • 제6권2호
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    • pp.73-81
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    • 2000
  • This study was carried out to measure the amount of outlet discharge and analyse the water quality from an agricultural reservoir. Joongpyong reservoir was selected as the monitoring site. Daily discharge was determined by measured water level data of delivery canal and the stage-discharge relation curve. The measured water discharge through culvert outlet of Joongpyong reservoir was 593,200m3 which was equivalent to irrigation depth 1,186mm during irrigation period in 1999. And water samples were taken from the surface water of reservoir and delivery canal, periodically. Temporal variation of water quality constituents such as water temperature, pH, EC, total nitrogen, total phosphorus were investigated. The result showed that pH was ranged 6.9 7.8, total nitrogen 1.39 4.11mg/L, total phosphorus 0.007 0.036 mg/L, respectively.

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한국재래산양 두부의 안면신경 분포에 관한 해부학적 연구 (Course and Distribution of Facial Nerve of the Korean Native Goat)

  • 이흥식;이인세;김대중
    • 대한수의학회지
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    • 제26권1호
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    • pp.1-9
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    • 1986
  • This study was carried out to investigate the branch and distribution of Nervus facialis of the Korean native goat. The observation was made by dissection of embalmed cadavers of ten Korean native goats. The results were as follows; 1. N. facialis arose from the ventrolateral surface of the medulla oblongata. 2. In the facial canal, N. facialis gave off N. petrosus major, N. stapedius and Chorda tympani. 1) N. petrosus major arose from Ganglion geniculi, passed through the pterygoid canal and terminated in Ganglion pterygopalatinum. 2) Chorda tympani joined N. lingualis at the lateral surface of the internal pterygoid muscle. 3. At the exit of the stylomastoid foramen, N. facialis gave off N. caudalis auricularis, Ramus auricularis internus, Ramus stylohyoideus and Ramus digastricus. 1) N. caudalis auricularis arose by two branches in 6 cases and by a single branch in 4 cases. N. caudalis auricularis gave off branches to the caudoauricuIar muscles and the internal surface of the conchal cavity. 2) Ramus auricularis internus arose by a single branch except in 2 cases in which it arose in common with N. caudalis auricularis. It penetrated the caudolateral surface of the tragus and distributed in the skin of the scapha. 3) Ramus stylohyoideus and Ramus digastricus arose separately from N. facialis. 4. In the deep surface of the parotid gland, N. facialis divided into N. auriculopalpebralis, Ramus buccalis dorsalis and Ramus buccalis ventralis. In 6 cases, N. facialis gave off Ramus buccalis ventralis and then divided into N. auriculopalpebralis and Ramus buccalis dorsalis. In 3 cases, N. facialis trifurcated into Ramus buccalis ventralis, Ramus buccalis dorsalis and N. auriculopalpebralis. In one case, N. facialis gave off N. auriculopalpebralis and then divided into Ramus buccalis dorsalis and Ramus buccalis ventralis. 1) Ramus buccalis ventralis ran along the ventral border of the masseter muscle and distributed to the buccinator and depressor labii inferioris muscles. Ramus buccalis ventralis communicated with a branch of Ramus buccalis dorsalis and N. buccalis. In 2 cases, it also communicated with N. mylohyoideus. 2) Ramus buccalis dorsalis communicated with Ramus transverses faciei, N. buccalis, N. infraorbitalis and a branch of Ramus buccalis ventralis. Ramus buccalis dorsalis distributed to the orbicularis oris, caninus, depressor labii inferioris, levator labii superioris, buccinator, malaris, nasolabialis and zygomaticus muscles. 3) N. auriculopalpebralis gave off Rami auriculares rostrales, which supplied the zygomaticoauricularis muscle, the frontoscutularis muscle and the skin of the base of the ear. N. auriculopalpebralis then continued as Ramus zygomaticus, which innervated the frontal muscle, the lateral surface of the base of the horn, the orbicularis oculi muscle and the adjacent skin of the orbit. N. auriculopalpebralis communicated with Nn. auriculares rostrales and Ramus zygomaticotemporalis. In 7 cases, it also communicated with N. infratrochlearis.

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주목과 잎갈나무의 나선장(螺旋狀) 구조(構造)에 관한 연구(硏究) (Studies on the Helical Structures of Taxus cuspidata S. et Z. and Larix gmelinii var. principis-ruprechtii Pilger)

  • 이필우;정희석;엄영근
    • Journal of the Korean Wood Science and Technology
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    • 제15권2호
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    • pp.79-89
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    • 1987
  • This study was executed to examine helical structure and other feature, of Taxus cuspidata S. et Z. and Larix gmelinii var. principis-ruprechtii Pilger through photomicroscopic and scanning electron microscopic observation, and the obtained result, were summarized as follows: 1. Tracheid transition from springwood to summerwood was abrupt, mel slightly gradual in Taxus cuspidata S. et Z. and summerwood width of Larix gmelinii var. principis-ruprechtii Pilger was wider than that of Taxus cuspidata S. et Z. 2. Normal vertical and horizontal resin canals and surrounding thick epithelial cells were present in Larix gmelinii var. principis-ruprechtii Pilger but not present in Taxus cuspidata S. et Z. 3. Instead of helical thickening, helical chicks were observed only in summerwood trachieds of Larix gmelinii var. principis-ruprechtii Pilger. However, helical thickenings forming S, Z., and horizontal helix perpendicular to long axis of tracheid were observed in springood and summerwood tracheids of Taxus cuspidata S. et Z. and these helical thickenings were considered as analogous to the innermost layer of secondary wall. 4. Uniseriate and fusiform rays were appeared on tangential surface of Larix gmelinii var. principis-ruprechtii Pilger but oly uniserate ray was observed on tangential surface ot Taxus cuspidata S. et Z. The fusiform rays of Larix gmelinii var. principis-ruprechtii Pilger usually contained one horizontal resin canal bot occasionally two horizontal resin canals were contained in a fusiform ray. 5. Trabeculae and crassulae were observed in the tracheids of Larix gmelimii var. principis-ruprechtii Pilger but not observed in the tracheids of Taxus cuspidata S. et Z.

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저수지 관개지구의 농업용수 회귀 특성 분석 (Characteristics of Irrigation Return Flow in a Reservoir Irrigated District)

  • 송정헌;송인홍;김진택;강문성
    • 한국농공학회논문집
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    • 제57권1호
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    • pp.69-78
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    • 2015
  • The objective of this study was to investigate characteristics of irrigation return flow from paddy block in a reservoir irrigated district during growing seasons. The irrigation return flow was divided into three parts, quick return flow from irrigation canal (RFI), quick return flow from drainage canal (RFD), and delayed return flow (DRF). The RFI was calculated from water level and stage-discharge relationships at the ends of the irrigation canals. The DRF was estimated using measured infiltration amount from paddy fields of the irrigated district. A combined monitoring and modeling method was used to estimate the RFD by subtracting surface runoff from surface drainage. The paddy block irrigated from the Idong reservoir was selected to study the irrigation return flow components. The results showed that daily agricultural water supply (AWS), the RFI, and the RFD were $27.4mm\;day^{-1}$, $4.9mm\;day^{-1}$, and $19.8mm\;day^{-1}$, respectively in May, which were greater than other months (p<0.05). The return flow ratio of the RFI and the RFD were the greatest in July (34.6%) and May (72.3%), respectively. The daily AWS was closely correlated with the RFD (correlation coefficients of 0.76~0.86) in except for July with, while correlation coefficient with the RFI were 0.56 and 0.42 in June and July, respectively (p<0.01). The total irrigation return flow was 1,965 mm in 2011, and 1,588 mm in 2012, resulting in total return flow ratio of 84.6% and 79.1%, respectively. This results indicate that substantial amounts of agricultural water were returned to streams as irrigation return flow. Thus, irrigation return flow should be fully considered into the agricultural water resources planning in Korea.

나선형 단층방사선사진촬영에서 촬영조건이 악골 단면상의 높이, 폭 및 인지도에 미치는 영향 (The effect of different radiographic parameters on the height, width and visibility of cross-sectional image of mandible in spiral tomography)

  • 이태완;한원정;김은경
    • Imaging Science in Dentistry
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    • 제33권1호
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    • pp.43-49
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    • 2003
  • Purpose : To evaluate the differences in bone height, bone width, and visibility of posterior spiral tomographic images according to various exposure directions, image layer thickness, and inclination of the mandibular inferior border. Materials and Methods: Six partially and completely edentulous dry mandibles were radiographed using Scanora spiral tomography. Spiral tomography was performed at different exposure directions (dentotangential and maxillotangential projection), image layer thicknesses (2 mm, 4 mm and 8 mm), and at various inclinations to the mandibular border (+ 100, 00 and -10°). The bone height and width was measured using selected tomographic images. The visibility of mandibular canal, crestal bone, and buccal and lingual surfaces were graded as 0, 1, or 2. Results : The bone width at the maxillo-tangential projection was wider than at the dento-tangential projection (p < 0.05). The visibility of buccal and lingual surface at the maxillo-tangential projection was higher than at the dento-tangential projection (p<0.05). Thinner image layer thicknesses resulted in greater visibility of buccal and lingual surfaces (p < 0.05). Bone height was greatest in the -10° group, and at the same time the bone width of the same group was the narrowest (p < 0.05). The visibility of alveolar crest and buccal surface of the + 10° group was the highest, while the visibility of the mandibular canal was greatest in the 00 group. Conclusion: When spiral tomography is performed at the mandibular posterior portion for visualization prior to implant surgery, it is important that the inferior border of mandible be positioned as parallel as possible to the floor. A greater improvement of visibility can be achieved by maintaining a thin image layer thickness when performing spiral tomography.

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