臺灣博碩士論文加值系統

雖然鎳鈦旋轉器械至今已被廣泛使用，但器械之斷裂機制仍然是製備根管最大的問題所在。過去本研究團隊已驗證實驗與有限元素分析有一致性，也已提出較佳的螺紋設計來達到分段切削之功效，故本研究以有限元素分析為基礎來提出較佳之截面設計，並評估不同截面設計之鎳鈦旋轉器械其力學行為。主要探討三種不同截面參數之設計，其中包括(a)與外接圓接點、(b)導平面寬度以及(c)三螺旋角度。分別給予器械之相同彎曲程度與扭轉度數之負載邊界條件，以評估於彎曲分析與扭轉分析中，各項參數變異對器械本身力學行為之影響。由彎曲分析結果發現，當減少與外接圓接點數，器械與根管壁之接觸面積有降低的趨勢；當導平面寬度及三螺旋角度增加，皆會導致器械之凹槽深度增加，進而減少器械表面之最大盟麥斯應力；多變化螺距之器械其彎曲應力較固定螺距低。由扭轉分析結果發現，三螺旋角度之截面設計以及螺距越小之器械，具有較大之彈性變形區域且勁度較低。透過本研究之電腦輔助工程分析，建議較佳之鎳鈦旋轉器械截面設計應為(1)具有三螺旋角度之設計；(2)與外接圓接點數為兩點，以降低器械與根管壁之接觸面積；(3)具有導平面與較小的核直徑，來增加器械彎曲彈性。透過上述器械改良之參數，可以減少器械彎曲斷裂及靜態扭轉斷裂之風險。

Recently, Nickel-Titanium (NiTi) rotary instruments have been widely used. However, instrument fracture is still a critical issue during canal preparation. From our previous studies, there is a high correlation between our experiments and finite element analysis. It is confirmed that the finite element analysis is a useful tool for the evaluation of rotary instruments. The design concept of the thread for the files is the cutting by stage and the alteration major cutting region. Thus, the goal of this study was to investigate the influence of three different cross-sectional design parameters on the mechanics of NiTi rotary instrument. The selected parameters are: (a) the number of points in contact with the circumferential circle of the file, (b) the width of radial land, (c) the angle of triple helix. The loading and boundary conditions were applied for bending and torsional simulations. In the bending simulation, when the number of points in contact with the circumferential circle was decreased, the contact area was reduced. When the width of the radial land and the angle of triple helix were increased, it would lead to a deeper flute and the maximum von Mises stress of the file is decreased. The stress of the file with various pitches is lower than that of files with uniform pitch. In the torsional simulation, the file with triple helix has longer region of elastic deformation and more flexible. When the pitch length of the file was reduced, the maximum von Mises stress was decreased and the region of elastic deformation for the rotary instrument was increased. According to the results, a better design of cross-sectional area for NiTi rotary instrument may be suggested: (1) the angle of the triple-helix would increase the flexibility; (2) two contact points with the circumferential circle may cause less contact area between the instrument and root canal; (3) larger radial land and smaller core diameter may increase the flexibility of the file. The risks of bending fracture and static torsional fractures may be reduced when the above design suggestions were adopted.

摘要 I
ABSTRACT II
致謝 III
目錄 IV
圖目錄 VII
表目錄 X
第一章 緒論 1
1-1 引言 1
1-2 研究背景與文獻回顧 4
1-2-1 切削能力 4
1-2-2 抵抗扭轉能力 8
1-2-3 彎曲能力 12
1-2-4 抵抗疲勞能力 15
1-3 研究目的 17
第二章 基礎理論 18
2-1 牙科生理學 18
2-2 根管治療簡介 20
2-3 材料力學簡介 21
2-4 根管用鎳鈦器械材料簡介 26
2-5 有限元素法簡介 28
第三章 材料與方法 30
3-1 研究流程 30
3-1-1 參數設定 31
3-1-2 模型建立 36
3-1-3 表面網格 42
3-1-4 有限元素分析 43
3-2 剛體彎道模擬 46
3-3 扭轉模擬 47
第四章 結果 48
4-1 剛體彎道模擬之力學分析 48
4-1-1 與外接圓接點 48
4-1-2 導平面寬度 51
4-1-3 三螺旋角度 54
4-1-4 螺距 56
4-2 扭轉模擬之力學分析 58
4-2-1 與外接圓接點 58
4-2-2 導平面寬度 63
4-2-3 三螺旋角度 67
4-2-4 螺距 70
第五章 討論 72
5-1 剛體彎道模擬之力學分析 72
5-2 扭轉模擬之力學分析 76
第六章 結論 78
6-1 剛體彎道模擬之力學分析 78
6-2 扭轉模擬之力學分析 78
參考文獻 79


圖目錄
圖1-1傾斜角示意圖：(A)正傾斜角、(B)負傾斜角 6
圖1-2導平面之示意圖 6
圖1-3核直徑及屑片移除容積之示意圖 7
圖1-4螺旋角之示意圖 7

圖2-1牙齒生理解剖圖 19
圖2-2根管治療過程步驟圖 20
圖2-3面積二次矩與面積慣性極力矩示意圖 25
圖2-4鎳鈦合金金屬的晶相轉換示意圖 26
圖2-5鎳鈦合金之應力-應變曲線圖【65】 27

圖3-1研究步驟流程圖 30
圖3-2與外接圓接點改變之截面設計圖：(A) F1、(B) 2pd、(C) 2pr、(D) 1pd、(E) 1pr 33
圖3-3導平面寬度改變之截面設計圖：導平面寬度分別為(A) F1、(B) 5˚、(C) 10˚、(D) 15˚、(E) 20˚、(F) 25˚、(G) 30˚、(H) 35˚ 34
圖3-4三螺旋角度改變之截面設計圖：角度分別為(A) F1、(B)15˚、(C) 30˚、(D) 45˚ 35
圖3-5與外接圓接點模型之截面圖：(A)F1、(B)2pd、(C)2pr、(D)1pd、(E)1pr 38
圖3-6導平面寬度模型之截面圖：(A) F1、(B) R5、(C) R10、(D) R15、(E) R20、(F) R25、(G) R30、(H) R35 39
圖3-7三螺旋角度模型之截面圖：(A)F1、(B)S15、(C)S30、(D)S45 39
圖3-8與外接圓接點模型之側視圖：(A) F1、(B) 2pd、(C) 2pr、(D) 1pd、(E) 1pr 40
圖3-9導平面寬度模型之側視圖：(A) F1、(B) R5、(C) R10、(D) R15、(E) R20、(F) R25、(G) R30、(H) R35 40
圖3-10三螺旋角度模型之側視圖：(A)F1、(B)S15、(C)S30、(D)S45 41
圖3-11螺距模型之側視圖：(A) P1.0、(B) P1.2、(C) P1.4、(D) P1.6、(E) P1.8、(F) P2.0、(G) P2.4、(H) P∞ 41
圖3-12器械分段網格示意圖 42
圖3-13鎳鈦旋轉器械之材料性質設定參數 45
圖3-14器械位移至深度10 mm之三維有限元素分析模型 46
圖3-15扭轉模擬之三維有限元素分析模型 47

圖4-1與外接圓接點之最大盟麥斯應力分佈圖：(A)F1、(B)2pd、(C)2pr、(D)1pd、(E)1pr 50
圖4-2導平面寬度之最大盟麥斯應力分佈圖：(A) F1、(B) R5、(C) R10、(D) R15、(E) R20、(F) R25、(G) R30、(H) R35 53
圖4-3三螺旋角度之最大盟麥斯應力分佈圖：(A) F1、(B) S15、(C) S30、(D) S45 55
圖4-4與外接圓接點之扭轉應力值 60
圖4-5與外接圓接點其扭轉46.8˚ ~ 54˚之斜率 61
圖4-6與外接圓接點其扭轉54˚之截面應力分佈圖 62
圖4-7導平面寬度之扭轉應力值(A)凸三角形(B)凹三角形 65
圖4-8導平面寬度其扭轉54˚之截面應力分佈圖 66
圖4-9三螺旋角度之扭轉應力 68
圖4-10三螺旋角度之塑性變形斜率 68
圖4-11三螺旋角度其扭轉54˚之截面應力分佈圖 69
圖4-12螺距之扭轉應力值 71


表目錄
表3-1外接圓接點模型之面積慣性極力矩(J)及面心二次矩(IX、IY) 36
表3-2導平面寬度模型之面積慣性極力矩(J)及面心二次矩(IX、IY) 37
表3-3三倍螺旋角度模型之面積慣性極力矩(J)及面心二次矩(IX、IY) 37
表3-4外接圓接點模型之元素個數 43
表3-5導平面寬度模型之元素個數 44
表3-6三倍螺旋角度模型之元素個數 44
表3-7螺距模型之元素個數 45

表4-1與外接圓接點之最大盟麥斯應力及接觸節點數量 49
表4-2改變導平面之最大盟麥斯應力及發生位置 52
表4-3器械最大盟麥斯應力及發生位置 54
表4-4改變螺距之最大盟麥斯應力及發生位置 57
表4-5導平面寬度之應力差異百分比(%) 64

【1】皮昕、方光明，口腔解剖生理學，合記圖書出版社，2007。
【2】沈領昌，專題報導美齒與科技根管治療的最新發展，科學發展，2005，394期。
【3】陳彥穎，鎳鈦旋轉器械之動態測試及有限元素分析，中原大學醫學工程學系碩士學位論文，2008。
【4】黃世明，鎳鈦旋轉器械應用於根管切削之力學行為分析，中原大學醫學工程學系碩士學位論文，2006。
【5】Alapati SB, Brantley WA, Svec TA, Powers JM, Nusstein JM, Daehm GS. SEM Observations of Nickel-Titanium Rotary Endodontic Instruments that Fractured During Clinical Use. J Endod 2005; 31: 40–43.
【6】Alapati SB, Brantley WA, Svec TA, Powers JM, Nusstein JM, Daehn GS. Proposed Role of Embedded Dentin Chips for the Clinical Failure of Nickel-Titanium Rotary Instruments. J Endod 2004; 30: 339–341.
【7】Al-Fouzan KS. Incidence of Rotary ProFile Instrument Fracture and the Potential for Bypassing In Vivo. Int Endod J 2003; 36: 864–867.
【8】Bergmans L, Van Cleynenbreugel J, Wevers M, Lambrechts P. Mechanical Root Canal Preparation with NiTi Rotary Instruments: Rationale, Performance and Safety. Am J Dent 2001; 14: 324–333.
【9】Berutti E, Chiandussi G, Gaviglio I, Ibba A. Comparative Analysis of Torsinal and Bending Stresses in Two Mathematical Models of Nickel-Titanium Rotary Instruments: ProTaper versus ProFile. J Endod 2003; 29: 15–19.
【10】Best S, Watson P, Pilliar R, Kulkarni GGK, Yared G. Torsional Fatigue and Endurance Limit of a Size 30 .06 ProFile Rotary Instrument. Int Endod J 2004; 37: 370–373.
【11】Blum JY, Cohen A, Machtou P, Micallef J-P. Analysis of Forces Developed During Mechanical Preparation of Extracted Teeth Using ProFile NiTi Rotary Instruments. Int Endod J 1999; 32: 24–31.
【12】Blum JY, Machtou P, Micallef JP. Location of Contact Areas on Rotary ProFile Instruments in Relationship to the Forces Developed During Mechanical Preparation on Extracted Teeth. Int Endod J 1999; 32: 108–114.
【13】Bryant ST, Thompson SA, al-Omari MA, Dummer Pm. Shaping Ability of ProFile Rotary Nickel-Titanium Instruments with ISO Sized Tips in Simulated Root Canals: Part 1. Int Endod J 1998; 31: 275–281.
【14】Calas P, Comtesse C, Deveaux E. Torsional Properties of a New Rotary Ni-Ti File, HERO 642 [abstract]. J Endod 1999; 25: 296.
【15】Camps JJ, Pertot WJ, Levallois B. Relationship Between File Size and Stiffness of Nickel-Titanium Instruments. Endod Dent Traumatol 1995; 11: 270–273.
【16】Camps JJ, Pertot WJ. Machining Efficiency of Ni-Ti K-type Fries in a Linear Motion. Int Endod J 1995; 28: 279–284.
【17】Camps JJ, Pertot WJ. Relationship Between File Size and Stiffness of Stainless Steel Instruments. Endod Dent Traumatol 1994; 10: 260–263.
【18】Camps JJ, Pertot WJ. Torsional and Stiffness Properties of Nickel-Titanium K Files. Int Endod J 1995; 28: 239–243.
【19】Chow DY, Stover SE, Bahcall JK, Jaunberzins A, Toth JM. In Vitro Comparison of the Rake Angles Between K3 and ProFile Endodontic File Systems. J Endod 2005; 31: 180–182.
【20】Crump MC, Natkin E. Relationship of Broken Root Canal Instruments to Endodontic Case Prognosis: a Clinical Investigation. J Am Dent Ass 1970; 80: 1341–1347.
【21】Diemer F, Calas P. Effect of Pitch Length on the Behavior of Rotary Triple Helix Root Canal Instruments. J Endod 2004; 30: 716–718.
【22】Dolan DW, Craig RG. Bending and Torsion of Endodontic Files. J Endod 1982; 8: 260–264.
【23】Esposito PT, Cunningham CJ. A Comparison of Canal Preparation with Nickel-Titanium and Stainless Steel Instruments. J Endod 1995; 21: 173–176.
【24】Felt RA, Moser JB, Heuer MA. Flute Design of Endodontic Instruments: its Influence on Cutting Efficiency. J Endod 1982; 6: 253–259.
【25】Foschi F, Nucci C, Montebugnoli L, Marchionni S, Breschi L, Malagnino VA, Prati C. SEM Evaluation of Canal Wall Dentine Following Use of Mtwo and ProTaper Ni-Ti Rotary Instruments. Int Endod J 2004; 27: 832–839.
【26】Gambarini G. Rationale for the Use of Low-Torque Endodontic Motors in Root Canal Instrumentation. Endod Dent Traumatol 2000; 16: 95–100.
【27】Gambarini, G. Cyclic Fatigue of Nickel-Titanium Rotary Instruments after Clinical Use with Low- and High-Torque Endodontic Motors. J Endod 2001; 27: 772–774.
【28】Guppy DR, Curtis RV, Pitt Ford TR. Dentin Chips Produced by Nickel-Titanium Rotary Instruments. Endod Dent Traumatol 2000; 16: 258–264.
【29】Haikel Y, Serfaty R, Bateman G, Senger B, Allemann C. Dynamic and Cyclic Fatigue of Engine-Driven Rotary Nickel-Titanium Endodontic Instruments. J Endod 1999; 25: 434–440.
【30】Harty FJ. Endodontics in Clinical Practice. 3rd Ed. London: Butterworth & Co.Ltd: 1990; 140.
【31】Hilt BR, Cunninghan CJ, Shen C, Richards N. Torsinal Properties of Stainless-Steel and Nickel-Titanium Files After Multiple Autoclave Sterilizations. J Endod 2000; 26: 76–80.
【32】Hülsmann M, Peters O, Dummer PMH. Mechanical Preparation of Root Canals. Shaping Goals, Techniques and Means. Endod Topics 2005; 10: 30–76.
【33】Jeon IS, Spangberg LSW, Yoon TC, Kazemi RB, Kum KY. Smear Layer Production by 3 Rotary Reamers with Different Cutting Blade Designs in Straight Root Canals: A Scanning Electron Microscopic Study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003; 96: 601–607.
【34】K3 - 3rd Generation Rotary Niti File for Precision Endodontics. SybronEndo Sales Sheet.
【35】Kim TO, Cheung GSP, Lee JM, Kim BM, Hur B, Kim HC. Stress distribution of three NiTi rotary files under bending and torsional conditions using a mathematic analysis. Int Endod J 2009; 42: 14–21.
【36】Kobayashi C, Yoshioka T, Suda H. A New Motor-Driven Canal Preparation System with Electronic Canal Measuring Capability. J Endod 1997; 23: 751–754.
【37】Koch K, Brave D. Real World Endo: Design Features of Rotary Files and How They Affect Clinical Performance. Oral Health 2002; 92: 39–49.
【38】Krupp J, Brantley W, Gerstein H. An Investigation of the Torsional and Bending Properties of Seven Brands of Endodontic Files. J Endod 1984; 10: 372–380.
【39】Machtou P, Ruddle CJ. Advancements in the Design of Endodontic Instruments for Root Canal Preparation. Alpha Omegan 2004; 97: 8–15.
【40】Matwychuk MJ, Bowles WR, McClanahan SB, Hodges JS, and Pesun IJ. Shaping Abilities of Two Different Engine-Driven Rotary Nickel-Titanium Systems or Stainless Steel Balanced-Force Technique in Mandibular Molars. J Endod 2007; 33: 868–871.
【41】Miserendino LJ. Instruments, Materials, and Devices. In: Cohen S, Burns RC, eds. Pathways of the pulp. 5th ed. St. Louis: Mosby Year Book, 1991; 377–413.
【42】Oliet S, Sorin SM. Cutting Efficiency of Endodontic Reamers. Oral Surf Oral Med Oral Pathol 1973; 36: 243–252.
【43】Park JB, Lakes RS. Biomaterials: an Introduction, 2nd ed. New York: Plenum Publishing 1992; 297–300.
【44】Peters OA, Barbakow F. Dynamic Torque and Apical Forces of ProFile .04 Rotary Instruments During Preparation of Curved Canals. Int Endod J 2002; 35: 379–389.
【45】Pongione G, Gambarini G, Bossu M. Bending and Torsional Properties of GT Rotary Files: a Comparative Study [abstract]. Int Endod J 2000; 33: 162.
【46】Roland DD, Andelin WE, Browning DF, Hsu G-HR, Torabinejad M. The Effect of Preflaring on the Rates of Separation for 0.04 Taper NiTi Rotary Instruments. J Endod 2002; 28: 543–555.
【47】Ruddle CL. Nickel-Titanium Rotary Systems: Review of Existing Instruments and Geometries. Dent Today 2000; 19: 86–95.
【48】Sattapan B, Nervo G, Palamara J, Messer H. Defects in Rotary Nickel-Titanium Files after Clinical Usage. J Endod 2000; 26: 161–165.
【49】Schäfer E, Dzepina A, Danesh G. Bending Properties of Rotary Nickel-Titanium Instruments. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003; 96: 757–763.
【50】Schäfer E, Erler M, Dammaschke T. Comparative Study on the Shaping Ability and Cleaning Efficiency of Rotary Mtwo Instruments. Part 2. Cleaning Effectiveness and Shaping Ability in Severely Curved Root Canals of Extracted Teeth. Int Endod J 2006; 39: 203–212.
【51】Schäfer E, Oitzinger M. Cutting Efficiency of Five Different Types of Rotary Nickel-Titanium Instruments. J Endod 2008; 34: 198–200.
【52】Schäfer E, Tepel J. Relationship Between Design Features of Endodontic Instruments and Their Properties. Part 3. Resistance to Bending and Fracture. J Endod 2001; 27: 299–303.
【53】Schäfer E, Vlassis M. Comparative Investigation of Two Rotary Nickel-Titanium Instruments: ProTaper versus RaCe. Part 2. Cleaning Effectiveness and Shaping Ability in Severely Curved Root Canals of Extracted Teeth. Int Endod J 2004; 37: 239–248.
【54】Schäfer E, Zapke K. A Comparative Scanning Electron Microscopic Investigation of the Efficiency of Manual and Automated Instrumentation of Root Canals. J Endod 2000; 26: 660–664.
【55】Schäfer E. Relationship Between Design Features of Endodontic Instruments and Their Properties. Part 1. Cutting Efficiency. J Endod 1999; 25: 52–55.
【56】Schrader C, Peters OA. Analysis of Torque and Force with Differently Tapered Rotary Endodontic Instruments in Vitro. J Endod 2005; 31: 120–123.
【57】Stoeckel D, Yu W. Superelastic Ni-Ti wire. Wire J Int 1991; 3: 45–50.
【58】Thompson SA, Dummer PMH. Shaping Ability of ProFile 0.04 Taper Series 29 Rotary Nickel-Titanium Instruments in Simulated Root Canals. Int Endod J 1997; 30: 5–18.
【59】Tripi TR, Bonaccorso A, Condorelli GG. Cyclic Fatigue of Different Nickel-Titanium Endodontic Rotary Instruments. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006; 102: 106–114.
【60】Turpin YL, Chagneau F, Vulcain JM. Impact of Two Theoretical Cross-Sections on Torsional and Bending Stresses of Nickel-Titanium Root Canal Instrument Models. J Endod 2000; 26: 414–417.
【61】Uei-Ming L, Bor-Shiunn L, Chin-Tsai S, Wan-Hong L, Chun PL. Cyclic Fatigue on Endodontic Nickel-Titanium Rotary Instruments: Static and Dynamic Tests. J Endod 2002; 28: 448–451.
【62】Ullmann CJ, Peters OA. Effect of Cyclic Fatigue on Static Fracture Loads in ProTaper Nickel-Titanium Rotary Instruments. J Endod 2005; 31: 183–186.
【63】Vertri M, Mollo A, Mantovani L, Pini P, Balleri P, Grandini S. A Comparative Study of Endoflare-Hero Shaper and Mtwo NiTi Instruments in the Preparations of Curved Root Canals. Int Endod J 2005; 38: 610–616.
【64】Wildey WL, Senia S, Montgomery S. Another Look at Root Canal Instrumentation. Oral Surg Oral Med Oral Pathol 1992; 74: 499–507.
【65】Xu X, Eng M, Zheng Y, Eng D. Comparative Study of Torsional and Bending Properties for Six Models of Nickel-Titanium Root Canal Instruments with Different Cross-Sections. J Endod 2006; 32: 372–375.
【66】Yao JH, Schwartz SA, and Beeson TJ. Cyclic Fatigue of Three Types of Rotary Nickel-Titanium Files in a Dynamic Model. J Endod 2006; 32: 55–57.