臺灣博碩士論文加值系統

一般的齒顎矯正治療時間多半會超過一年，金屬矯正托架會因長時間暴露在溫暖潮濕的口腔環境中產生鏽蝕作用。矯正器在口中產生鏽蝕作用可能會削弱其本身機械性質，造成矯正托架表面型態的改變、磨損率升高，而影響齒顎矯正治療的效果。再者，鏽蝕產生之金屬離子可能對人體產生不良影響，如重金屬中毒、牙表面琺瑯質著金屬色及對鎳元素過敏等現象。
本研究的目的使用相同316L不鏽鋼金屬，比較其一體注射成型(A組)、焊接型(B組)及焊接型不含焊料金屬(C組)等不同製作方式的矯正托架在37℃、pH7.0環境下經五個月的浸泡人工唾液後，以光學顯微鏡觀察表面結構的變化，以電子顯微鏡及x放射線能量散佈分析儀測定其元素組成，以原子力顯微鏡測量表面粗糙度的變化，並以感應耦合電漿質譜儀測量比較人工唾液中所釋出的不同金屬離子濃度以瞭解其抗腐蝕性。其結果以統計學方法分析之。
結果顯示在光學顯微鏡觀察下，矯正托架在浸泡第三個月後始顯現出鏽蝕現象，A、B兩組均可在托架之翼部、基底和溝槽等部位邊緣發現鏽蝕現象，但兩組之好犯部位不同，A組易出現在轉角處，而B組易出現在焊接部及基底的邊緣，並且程度上B組顯得較嚴重。x放射線能量散佈分析儀測出，三組矯正托架的金屬主成份含鐵、鉻及鎳，但是在B組的焊接部測到大量的金元素。金屬離子釋出方面，C組鐵、鎳及鉬的釋出隨時間而增加，而B組僅鎳及鉬的釋出隨時間而增加。在同樣浸泡時間下，C組顯示較多的鐵、鉻及鉬的釋出，而鎳的釋出在B組顯得較高，在統計學上有意義。表面粗糙度的測量上三組樣品均未顯示明顯的改變，唯B組在第一和第四個月粗糙度顯得較高，但在統計上未顯出意義。
結論是在37℃ pH值7.0環境下浸泡人工唾液五個月，矯正托架在光學顯微鏡觀察下第三個月始可看到�袘k現象，A、B兩組均可在托架之翼部、基底和溝槽等部位邊緣發現鏽蝕現象，但兩組之好犯部位不同，A組易出現在轉角處，而B組易出現在焊接部及邊緣，並且程度上B組顯得較嚴重。B組焊接部的主成份是金元素。比較金屬離子釋出鐵、鎳及鉬的釋出隨時間而增加; 比較三種矯正器來說，C組顯示較多鐵、鉻及鉬的釋出，而B組釋出較高的鎳。表面粗糙度的比較三種矯正器隨時間變化差異不明顯。

The ordinary orthodontic treatment would process for one year or longer. The metallic brackets would expose to a warm and humid oral environment for a long time and may suffer from corrosion. Corrosion may diminish the mechanical properties of the brackets and increase the wear rate, resulting in a poor orthodontic prognosis. Furthermore, corrosive ions release may cause adverse effects in the mouth, such as heavy metal toxicity, enamel discoloration or nickel hypersensitivity.
The purpose of this study was to compare the changes of the surface morphology, ion release, and surface roughness of the 316L stainless steel brackets which were one piece injection molding type (group A), soldering type (group B) and soldering type without solder (group C) for various long time immersions in the artificial saliva under 37℃ at pH 7.0. These changes were observed by optic microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and detected by atomic force microscope (AFM) respectively. The ion concentrations of the artificial saliva were measured by inductively coupled plasma-mass spectrometry (ICP-MS). The results were analyzed statistically.
The results demonstrated that after immersion in the 37℃ pH7.0 artificial saliva, the corrosion phenomenons were first detected in the 3rd month under OM observation. These phenomenons could be found over the edge of the wing, slot and base in both A and B group. However, the locations easily attacked by corrosion in group A were different from those in group B while group A were at the reflection corner and group B were at the border near the brazing joint and the base. Besides, corrosion attacks were more severe in group B than in group A.
The three groups of brackets were mainly composed of Fe, Cr and Ni and group B had large proportion of gold over the brazing joint by EDS detection. As for the ions release, Fe, Ni and Mo release increased with time in the C group while Ni and Mo release increased with time in the B group. Ion release in the group A was relatively constant as the time went by. During the same period of time, Fe, Cr and Mo release revealed the most in the C group while Ni release revealed the most in the B group. There were no statistically significant changes of the surface roughness among the three types of brackets for the five months immersion. The group B brackets had higher surface roughness at the first and fourth month immersion groups, however, it revealed no statistic significance.
The conclusion was that after immersion for five months in the 37℃ pH7.0 artificial saliva, the corrosion phenomenons were first detected in the 3rd month under OM observation. These phenomenons could be found over the edge of the wing, slot and base in both A and B group. However, the easily corrosive locations were different while group A were at the reflection corner and group B were at the border near the brazing joint and the base. Besides, corrosion attacks in group B were more severe than group A. Gold was the main element of the soldering alloy of the two pieces bracket. Comparing the ion release, Fe, Ni, Mo increased as the time went by. Among the three types of brackets, group C appeared to have more Fe, Cr and Mo release while group B appeared to have more Ni release. There were no obvious differences of the surface roughness during five months immersion test among the three groups of brackets.

Contents

封面…………………………………………………………………I
謝誌………………………………………………………………..II
中文摘要…………………………………………………………...III
Abstract……………..…………………………………………. VI
Content…………………………………………………………....IX
Table captions…………………………………………………...XI
Figure captions……………….………………………………...XIII

Introduction………………………………………....................p.1-6
Materials and methods………………………………………p.7-11
Results…………………………………………...…………..p.12-23
Discussion................................................................................p.24-33
Conclusion....................................................................................p.34
Acknowledgement……………………………………………...p.35
Reference………………………………………………………..p.94


Table captions

Table I. Brackets types…………………..……………….……..p. 36
Table II. The immersion time and grouping…………………….p. 37
Table III. Content of Sali Lube artificial saliva…………………p. 38
Table IV. Elemental compositions (wt%) determined by EDS...p. 39
Table V. Mean ion release concentration (ppb (μg/L))………...p.40
Table VI. Mean ion release concentration (ppb (μg/L))………...p.93


Figure captions
Figure 1-9 OM observations of the cross section view of the brackets…...p.42-50
Figure 1. The bracket slot of the control A and B group……….....................................................p.42
Figure 2.The bracket slot of the A and B group before and after immersion for 2,3 and 5 month P.43
Figure 3. The wing of the control A and B group…………………………………………….......P.44
Figure 4. The wing of the A and B group before and after immersion for 3 months……………..p.45
Figure 5. Lateral cross section view of the brazing joint of the control B group………………....p.46
Figure 6. The brazing joint of the B group before and after immersion for 2, 3, 4 and 5 months...p.47
Figure 7. The border of the brazing joint of the B group before and after immersion for 3 and 5 months…………………………………………………………………………..….…...p.48
Figure 8. The bracket base of the control A and B group………………………………….…...…p.49
Figure 9. The bracket base of the control A and B group before and after immersion for 3 and 5 months………………………………………………...………………………….……..p.50
Figure 10-20 SEM observation of the brackets……………...………......p.51-61
Figure 10. The plain view of the control sample of the group A bracket………….………...……p.51
Figure 11. The top plain view of control sample of group B bracket wing……...………………..p.52
Figure 12. The lateral view of control sample of group B bracket after slightly grinding...……...p.53
Figure 13. The plain view of the control sample of group C bracket laterally and posteriorly...…p.54
Figure 14. The plain view of mesh base of the control sample of group C bracket………………p.55
Figure 15. The plain view of group A bracket slot after immersion for 5 months…………….....p.56
Figure 16. The plain view of the group B bracket after immersion for 5 months………………...p.57
Figure 17. The cross section view of control sample of group A bracket slot…………………....p.58
Figure 18. The cross section view of control sample of group B brazing joint…………………...p.59
Figure 19. The cross section view the group A bracket after immersion for 5 months…………...p.60
Figure 20. the cross section view the group B bracket after immersion for 5 months…………....p.61
Figure 21-29 EDS spectra of the brackets...................................................p.62-70
Figure 21. Cntrol sample of group A bracket body over random three points…………………....p.62
Figure 22. Control sample of group B bracket over random one point of the bracket body…....p.63 Figure 23. Spectra, SEM image and elemental compositions of control sample of group B bracket over random one point of the brazing alloy……………………………………………….....……p.64
Figure24. Control sample of group B bracket over random one point of mesh base……………..p.65
Figure 25. Control sample of group C bracket over random three points………………....….…..p.66
Figure 26. Group A bracket after 5 months immersion over random three points……………......p.67
Figure 27. Group B bracket after 5 months immersion near the brazing area…………………….p.68
Figure 28. Group C bracket after 5 months immersion over three random points …………….....p.69
Figure 29. Mapping of EDS spectra over the brazing joint of the group B bracket after 5 months immersion…………………………………………………………………………………......…..p.70
Figure 30-33 Ion release of the three types of brackets……...……p.71-74
Figure 30. Iron ion release of the three various types of brackets for the 5 months immersion p.71 Figure 31. Nickel ion release of the three various types of brackets for the 5 months immersion.p.72
Figure 32. Chromium ion release of the three various types of brackets for 5 months immersion.p.73
Figure 33. Molybdenum ion release of the three various types of brackets for the 5 months immersion…………………………………………………………………..……….………….…p.74
Figure 36-54 AFM detections during 5 months…………………...p.75-92
Figure 34. Control sample of group A bracket……………………………………………….….p.75
Figure 35. Control sample of group B bracket……………………………..……………….…….p.76
Figure 36. Control sample of group C bracket……………………………………...…..………...p.77
Figure 37 Group A bracket after immersion one month…………………………...…………......p.78
Figure 38 Group B bracket after immersion one month……………………………….……..…..p.79
Figure 39 Group C bracket after immersion one month………………………………….……….p.80
Figure 40 Group A bracket after immersion two month…………………………..…….……......p.81
Figure 41 Group B bracket after immersion two month……………………………………….....p.82
Figure 42 Group C bracket after immersion two month………………………………….……....p.83
Figure 43 Group A bracket after immersion three month………………………...…..………......p.84
Figure 44 Group B bracket after immersion three month………………………………………....p.85
Figure 45 Group C bracket after immersion three month……………………………………...….p.86
Figure 46 Group A bracket after immersion four month………………………...…..…………....p.87
Figure 47 Group B bracket after immersion four month……………………………………...…..p.88
Figure 48 Group C bracket after immersion four month……………………………………...…..p.89
Figure 49 Group A bracket after immersion five month………………………...…..…………....p.90
Figure 50 Group B bracket after immersion five month……………………………………...…..p.91
Figure 51 Group C bracket after immersion five month……………………………………...…..p.92

References
1. Proffit WR. Contemporary orthodontic appliances. In " Contemporary Orthodontics " 4th ed, Proffit WR, Fields HW, Sarver DM ed, Mosby Co, St. Louis, pp.414, 2007.
2. Eliades T. Orthodontic brackets. In " Orthodontic Material - Scientific and Clinical Aspects " 3rd ed, Eliades T, Eliades G, Brantley WA ed, Mosby Co, St. Louis, pp.144, 2001.
3. Reynolds IR. A review of direct orthodontic bonding. Br J Orthod, 2:171-178, 1975.
4. Faltermeier A, Behr M, Mussig D. Esthetic brackets: the influence of filler level on color stability. Am J Orthod Dentofacial Orthop, 132:5.e13-5.e16, 2007.
5. Olsen ME, Bishara SE, Jakobsen JR. Evaluation of the shear bond strength of different ceramic bracket base designs. Angle Orthod, 67:179-182, 1997.
6. Sinha PK, Nanda RS. The effect of different bonding and debonding techniques on debonding ceramic orthodontic brackets. Am J Orthod Dentofacial Orthop, 112:132-137, 1997.
7. Arici S, Regan D. Alternatives to ceramic brackets: the tensile bond strengths of two aesthetic brackets compared ex vivo with stainless steel foil-mesh bracket bases. Br J Orthod, 24:133-137, 1997.
8. Birnie D. Ceramic brackets. Br J Orthod, 17:71-74, 1990.
9. Creekmore TD, Kunik RL. Straight wire: the next generation. Am J Orthod Dentofacial Orthop, 104:8-20, 1993.
10. Maijer R, Smith DC. Corrosion of orthodontic bracket bases. Am J Orthod, 81:43-48, 1982.
11. Wilkinson JV. Some metallurgical aspects of orthodontic stainless steel. Am J Orthod, 48:192-206, 1962.
12. Matasa CG. Biomaterials in orthodontics. In " Orthodontics: Current Principles and Techniques " 4th ed, Graber TM ed, Mosby Co, St. Louis, pp.356-369, 2005.
13. Matasa CG. Attachment corrosion and its testing. J Clin Orthod, 29:16-23, 1995.
14. Anusavice KJ, Brantley WA. Physical properties of dental materials. In " Phillips'' Science of Dental Materials " 11th ed, Anusavice KJ ed, Saunders Co, St. Louis, pp.57, 2003.
15. Kerosuo H, Moe G, Hensten-Pettersen A. Salivary nickel and chromium in subjects with different types of fixed orthodontic appliances. Am J Orthod Dentofacial Orthop, 111:595-598, 1997.
16. Matasa CG. Characteristics of used orthodontic brackets. In " Dental Materials in Vivo: Aging and Related Phenomena " 1st ed, Eliades G ed, Quintessence Pub. Co, Chicago, pp.365-9, 2003.
17. Eliades T, Athanasiou AE. In vivo aging of orthodontic alloys: implications for corrosion potential, nickel release, and biocompatibility. Angle Orthod, 72:222-237, 2002.
18. Eliades T. Orthodontic materials research and applications: part 2. Current status and projected future developments in materials and biocompatibility. Am J Orthod Dentofacial Orthop, 131:253-262, 2007.
19. Gioka C, Eliades T. Materials-induced variation in the torque expression of preadjusted appliances. Am J Orthod Dentofacial Orthop, 125:323-328, 2004.
20. von Fraunhofer JA. Corrosion of orthodontic devices. Semin Orthod, 3:198-205, 1997.
21. Peltonen L. Nickel sensitivity in the general population. Contact Dermatitis, 5:27-32, 1979.
22. Peltonen L. Nickel sensitivity. An actual problem. Int J Dermatol, 20:352-353, 1981.
23. Jensen CS, Lisby S, Baadsgaard O, Byrialsen K, Menne T. Release of nickel ions from stainless steel alloys used in dental braces and their patch test reactivity in nickel-sensitive individuals. Contact Dermatitis, 48:300-304, 2003.
24. Jacobsen N, Hensten-Pettersen A. Nickel. Nor Tannlaegeforen Tid, 91:259-262, 1981.
25. Mockers O, Deroze D, Camps J. Cytotoxicity of orthodontic bands, brackets and archwires in vitro. Dent Mater, 18:311-317, 2002.
26. Pigatto PD, Guzzi G. Systemic contact dermatitis from nickel associated with orthodontic appliances. Contact Dermatitis, 50:100-101, 2004.
27. Kerosuo H, Kanerva L. Systemic contact dermatitis caused by nickel in a stainless steel orthodontic appliance. Contact Dermatitis, 36:112-113, 1997.
28. Gwinnett AJ. Corrosion of resin-bonded orthodontic brackets. Am J Orthod, 81:441-446, 1982.
29. Leirskar J. On the mechanism of cytotoxicity of silver and copper amalgams in a cell culture system. Scand J Dent Res, 82:74-81, 1974.
30. Wataha JC, Hanks CT, Craig RG. In vitro effects of metal ions on cellular metabolism and the correlation between these effects and the uptake of the ions. J Biomed Mater Res, 28:427-433, 1994.
31. Brockhurst PJ, Pham HL. Orthodontic silver brazing alloys. Aust Orthod J, 11:96-99, 1989.
32. Park HY, Shearer TR. In vitro release of nickel and chromium from simulated orthodontic appliances. Am J Orthod, 84:156-159, 1983.
33. Grimsdottir MR, Gjerdet NR, Hensten-Pettersen A. Composition and in vitro corrosion of orthodontic appliances. Am J Orthod Dentofacial Orthop, 101:525-532, 1992.
34. Kerosuo H, Moe G, Kleven E. In vitro release of nickel and chromium from different types of simulated orthodontic appliances. Angle Orthod, 65:111-116, 1995.
35. Huang TH, Yen CC, Kao CT. Comparison of ion release from new and recycled orthodontic brackets. Am J Orthod Dentofacial Orthop, 120:68-75, 2001.
36. International Organization for Standardization. Biological evaluation of medical devices - part 5: Tests for in vitro cytotoxicity. 1st ed, Gen''eve: Switzerland, pp.1-7, 1999.
37. Neter J, Wasserman W, Kutner MH. Applied Linear Statistical Models. 4thed, Homewood: Irwin, pp.663-696, 1985.
38. Hartwig T, Veltl G, Petzoldt F, Kunze H, Scholl R, Kieback B. Powders for metal injection molding. J Eur Ceramic Soc, 18:1211-1216, 1998.
39. Loh N, German R. Statistical analysis of shrinkage variation for powder injection molding. J Mater Processing Technol, 59:278-284, 1996.
40. Castro L, Merino S, Levenfeld B, Varez A, Torralba J. Mechanical properties and pitting corrosion behavior of 316L stainless steel parts obtained by a modified metal injection molding technique. J Mater Processing Technol, 143-144:397–402, 2003.
41. Wataha JC, Lockwood PE. Release of elements from dental casting alloys into cell-culture medium over 10 months. Dent Mater, 14:158-163, 1998.
42. Wataha JC, Lockwood PE, Khajotia SS, Turner R. Effect of pH on element release from dental casting alloys. J Prosthet Dent, 80:691-698, 1998.
43. Covington JS, McBride MA, Slagle WF, Disney AL. Quantization of nickel and beryllium leakage from base metal casting alloys. J Prosthet Dent, 54:127-136, 1985.
44. Dencker I, Fristedt B, Ovrum P. Evaluation studies in Dalby. 9. Iron, copper, chromium, nickel, lead and cobalt in the diet. Lakartidningen, 68:4027-4030, 1971.
45. Schroeder HA, Balassa JJ, Tipton IH. Abnormal trace metals in man--nickel. J Chronic Dis, 15:51-65, 1962.
46. Grandjean P. Human exposure to nickel. IARC Sci Publ, 469-485, 1984.
47. Locci P, Lilli C, Marinucci L, Calvitti M, Belcastro S, Bellocchio S, Staffolani N, Guerra M, Becchetti E. In vitro cytotoxic effects of orthodontic appliances. J Biomed Mater Res, 53:560-567, 2000.
48. Merritt K, Brown SA. Metal sensitivity reactions to orthopedic implants. Int J Dermatol, 20:89-94, 1981.
49. Jendresen MD, Glantz PO. Clinical adhesiveness of selected dental materials. An in-vivo study. Acta Odontol Scand, 39:39-45, 1981.
50. Edie JW, Andreasen GF, Zaytoun MP. Surface corrosion of nitinol and stainless steel under clinical conditions. Angle Orthod, 51:319-324, 1981.
51. Kerosuo H, Kullaa A, Kerosuo E, Kanerva L, Hensten-Pettersen A. Nickel allergy in adolescents in relation to orthodontic treatment and piercing of ears. Am J Orthod Dentofacial Orthop, 109:148-154, 1996.
52. Schuster G, Reichle R, Bauer RR, Schopf PM. Allergies induced by orthodontic alloys: incidence and impact on treatment. Results of a survey in private orthodontic offices in the Federal State of Hesse, Germany. J Orofac Orthop, 65:48-59, 2004.
53. Merk O, Speit G. Detection of crosslinks with the comet assay in relationship to genotoxicity and cytotoxicity. Environ Mol Mutagen, 33:167-172, 1999.
54. Hartwig A, Snyder RD, Schlepegrell R, Beyersmann D. Modulation by Co(II) of UV-induced DNA repair, mutagenesis and sister-chromatid exchanges in mammalian cells. Mutat Res, 248:177-185, 1991.
55. Faccioni F, Franceschetti P, Cerpelloni M, Fracasso ME. In vivo study on metal release from fixed orthodontic appliances and DNA damage in oral mucosa cells. Am J Orthod Dentofacial Orthop, 124:687-694, 2003.
56. Lin MC, Lin SC, Lee TH, Huang HH. Surface analysis and corrosion resistance of different stainless steel orthodontic brackets in artificial saliva. Angle Orthod, 76:322-329, 2006.
57. Davison RM, Debold T, Johnson MJ. Corrosion of stainless steel. In " Metals Handbook: Volume 13 Corrosion " 9th ed, Korb LJ, Olson DL ed, American Society for Metal (ASM) International, Metals Park, Ohio, pp.547, 1988.
58. Evans UR. The mechanism of corrosion. J Chem Soc, 11:111, 1929.
59. Floria G, Franchi L. Metal injection molding in orthodontics. Virtual J Orthod, 2.1:1-5, 1997.
60. Cohrt H. Metal injection molding. Material World, 7:201-203, 1999.
61. Castro L, Merino S, Levenfeld B, Varez A, Torralba J. Mechanical properties and pitting corrosion behavior of 316L stainless steel parts obtained by a modified metal injection molding technique. J Mater Processing Technol, 143-144, 397-402, 2003.
62. Eliades T, Zinelis S, Eliades G, Athanasiou AE. Characterization of as-received, retrieved, and recycled stainless steel brackets. J Orofac Orthop, 64:80-87, 2003.
63. Agaoglu G, Arun T, Izgi B, Yarat A. Nickel and chromium levels in the saliva and serum of patients with fixed orthodontic appliances. Angle Orthod, 71:375-379, 2001.
64. Berge M, Gjerdet NR, Erichsen ES. Corrosion of silver soldered orthodontic wires. Acta Odontol Scand, 40:75-79, 1982.
65. Eliades T, Zinelis S, Eliades G, Athanasiou AE. Nickel content of as-received, retrieved, and recycled stainless steel brackets. Am J Orthod Dentofacial Orthop, 122:217-220, 2002.
66. Zinelis S, Annousaki O, Eliades T, Makou M. Elemental composition of brazing alloys in metallic orthodontic brackets. Angle Orthod, 74:394-399, 2004.