FRACTURE STRENGTH BETWEEN DIFFERENT CONNECTOR DESIGNS OF ZIRCONIA CORE FOR POSTERIOR FIXED PARTIAL DENTURES MANUFACTURED WITH CAD/CAM SYSTEM

CAD/CAM을 이용한 구치부 전부도재 고정성 국소의치 지르코니아 코어의 연결부 설계에 따른 파절강도

  • Seo Jun-Yong (Dept. of Prosthodontics, college of Dentistry, Yonsei University) ;
  • Park In-Nim (Dept. of Dentistry, Korea Medical Insurance Corporation Ilsan Hospital) ;
  • Lee Keun-Woo (Dept. of Prosthodontics, college of Dentistry, Yonsei University)
  • 서준용 (연세대학교 치과대학 보철학교실) ;
  • 박인임 (국민건강보험공단 일산병원 보철과) ;
  • 이근우 (연세대학교 치과대학 보철학교실)
  • Published : 2006.02.01

Abstract

Statements of problem: Zirconia core is used for posterior fixed partial dentures because it's good mechanical properties. Stress is concentrated on connectors in fixed partial dentures, so the proper design of connector areas is needed for adequate mechanical long-term properties of any prosthesis. The area of connector is critical, but tooth size and surrounding soft tissue limit the connector design. Purpose: The purpose of this study is to compare fracture strengths between different connector designs of zirconia core for posterior fixed partial dentures manufactured with CAD/CAM system and determining the optimal connector design satisfying strength and hygiene. Material and method: The following four groups of 40 posterior fixed partial denture specimens(each group 10) were fabricated as followed; group 1 vertical height of connector is 3mm (control group, all groups have the same condition); group 2, lingual vertical 1mm reinforcement on connector; group 3, lingual vertical 2mm reinforcing on connector and group 4, lingual vertical 3mm reinforcing on connector. Specimens were subjected to compressive loading on the central fossa of pontic by instron. SEM was used to identify the initial crack and characterize the fracture mode. Results: The results were as follows: 1. The mean fracture load of the non-lingual reinforcing group was 1212N and the lingual vertical 1mm reinforcing group was 1510N, the lingual vertical 2mm reinforcing group was 1882N, the lingual vertical 3mm reinforcing group was 1980N. 2. The reinforcing groups were statistically significant compared to non-reinforcing groups(P<0.001). 3. There were 2, 3mm reinforcing groups that were statistically significant compared to 1mm reinforcing groups(P<0.001), and the 3mm reinforcing group was not statistically significant compared to 2mm reinforcing groups(P>0.05) 4. Fractures were initiated in gingival embrasures of connectors and processed to the loading site. Conclusion: In this study, lingual reinforcement of connector for improved strength of zirconia based fixed partial denture is nessasary. And long-term study for clinical application is required

Keywords

References

  1. Ardlin BI. Transformation-toughened zirconia for dental inlays. crowns and bridges: chemical stability and effect of low-temperature aging on flexural strength and sur-face structure. Dent Mater 2002; 18: 590-595 https://doi.org/10.1016/S0109-5641(01)00095-1
  2. Sobrinho LC. Cattell MJ. Glover RH, Knowles JC. Investigation of the dry and wet fatigue properties of three all-ceramic crown systems. lnt J Prosthodont 1998: 11: 255-262
  3. Campbell SD. Sozio RB. Evaluation of the fit and strength of an all-ceramic fixed partial denture. J Prosthet Dent 1998; s59: 301-306
  4. Nakamura T. Ohyama T. lmanishi A, lshigaki S. Fracture resistance of press able glass-ceramic fixed partial dentures. J Oral Rehabilitation 2002: 29: 951-955 https://doi.org/10.1046/j.1365-2842.2002.00929.x
  5. Tinschert J. Natt G. Mautsch W. Augthun M. Spiekermann H. Fracture resistance of lithium disilicate- ,alumina- ,and zirconiabased three-unit fixed partial dentures: laboratory study. lnt J Prosthodont 2001: 14:231-238
  6. Piconi C. Maccauro G. Review zirconia as a ceramic biomaterial. Biomaterials 1999: 20:1-25 https://doi.org/10.1016/S0142-9612(98)00010-6
  7. Guazzato M. Albakry M. Ringer SP, Swain MV. Strength. fracture toughness and microstructure of a selection of all-ceramic materials. Part I. Pressable and alumina glass-infiltrated ceramics. Dent Mater 2004:20:441-448 https://doi.org/10.1016/j.dental.2003.05.003
  8. Tinschert J. Natt G. Mautsch W. Spiekermann H. Anusavice KJ. Marginal fit of alumina- and zirconia-based fixed partial dentures produced by a CAD/CAM system. Operative Dent 2001:26:367-374
  9. Luthardt RG, Sandkuhl O, Herold V, Walter MH. Accuracy of mechanical digitizing with a CAD/CAM system for fixed restorations. Int J Prosthodont 2001: 14: 146-151
  10. Willer J, Rossbach A, Weber HP. Computerassisted milling of dental restorations using a new CAD/CAM data acquisition system. J Prosthet Dent 1998:80:346-351 https://doi.org/10.1016/S0022-3913(98)70136-2
  11. El-Ebrashi MK, Craig RG, Peyton FA. Experimental stress analysis of dental restorations. Part VlI. Structural design and stress analysis of fixed partial dentures. J Prosthet Dent 1970:23:177-186 https://doi.org/10.1016/0022-3913(70)90295-7
  12. Kelly JR, Tesk JA Sorensen JA. Failure of all-ceramic fixed partial dentures in vitro and in vivo: analysis and modeling. J Dent Res 1995:74:1253-1258 https://doi.org/10.1177/00220345950740060301
  13. Fischer H, Weber M, Marx R. Lifetime prediction of all-ceramic bridges by computational methods. J Dent Res 2003: 82:238-242 https://doi.org/10.1177/154405910308200317
  14. Kupiec KA, Wuertz KM, Barkmeier WW, Wilwerding TM. Evaluation of porcelain surface treatments and agents for composite to porcelain repair. J Prosthet Dent 1996: 76: 119-124 https://doi.org/10.1016/S0022-3913(96)90294-2
  15. Guazzato M, Albakry M, Ringer SP, Swain MV. Strength, fracture toughness and microstructure of a selection of all-ceramic materials. Part II. Zirconia-based dental ceramics. Dent Mater 2004:20:449-456 https://doi.org/10.1016/j.dental.2003.05.002
  16. Ritter JE. Predicting lifetimes of materials and material structures. Dent Mater 1995: 11: 142-146 https://doi.org/10.1016/0109-5641(95)80050-6
  17. Nam-Sik Oh, Han-Sung Kim, Myung-Hyun Lee, Keun-Woo Lee. The optimal design of connectors in all ceramic fixed partial dentures manufactured from alumina tape. J Korean Academy Prosthodont 2004:42: 125-132
  18. Christel P, Meunier A, Heller M. Mechanical properties and short term in-vivo evaluation of yttrium-oxide-partially-stabilized zirconia. J Biomed Mater Res 1989:23:45-61 https://doi.org/10.1002/jbm.820230105
  19. Guazzato M, Proos K. Sara G, Swain MV. Strength, reliability and mode of fracture of bilayered porcelain/core ceramics. Int J Prosthodont 2004: 17 : 142-149
  20. MeLaren EA, Terry DA. CAD/CAM systems, materials, and clinical guidelines for all-ceramic crowns and fixed partial dentures. Compendium 2002:23:637-653
  21. Tinschert J, Zwez D, Marx R, Anusavice KJ. Structural reliability of alumina-. feldspar-, leucite-, mica- and zirconiabased ceramics. J Dent 2000: 28: 529-535 https://doi.org/10.1016/S0300-5712(00)00030-0
  22. Oh WS, Anusavice KJ. Effect of connector design on the fracture resistance of all-ceramic fixed partial dentures. J Prosthet Dent 2002:87 :536-542 https://doi.org/10.1067/mpr.2002.123850
  23. Sorensen JA, Cruz M, Mito WT, Raffeiner O, Meredith HR, Foser HP. A clinical investigation on three-unit fixed partial dentures fabricated with a lithium disilicate glass-ceramic. Pract Perio Aesthet Dent 1998: 11: 95-106
  24. Kamposiora P, Papavasiliou G, Felton DA. Stress concentration in all-ceramic posterior fixed partial dentures. Quintessence Int 1996:27:701-706
  25. Derand P, Derand T. Bond strength of luting cements to zirconium oxide ceramics. Int J Prosthodont 2000: 13: 131-135
  26. McCormick JT, Rowland W, Shillingburg Jr HT, Duncanson Jr MG. Effect of luting media on the compressive strengths of two types of all-ceramic crown. Quintessence Int 1993:24:405-408
  27. Diaz-Arnold AM, Vargas MA, Haselton DR. Current status of luting agents for fixed prosthodontics. J Prosthet Dent 1999: 81:135-141 https://doi.org/10.1016/S0022-3913(99)70240-4
  28. Kelly JR. Clinically relevant approach to failure testing of all-ceramic restorations. J Prosthet Dent 1999: 81: 652-661 https://doi.org/10.1016/S0022-3913(99)70103-4
  29. Korber KH. Ludwig K. Maximal biting force as a factor for consideration in the fabrication of dental restorations. Dent Lab 1983 :31: 55-60
  30. Oh WS. Gotzen N. Anusavice KJ. Influence of connector design on fracture probability of ceramic fixed-partial dentures. J Dent Res 2002:81:623-627 https://doi.org/10.1177/154405910208100909
  31. Koutayas SO. Kern M. Ferraresso F. Stub JR. Influence of design and mode of loading on the fracture strength of all-ceramic resin-bonded fixed partial dentures:An in vitro study in a dual-axis chewing simulator. J Prosthet Dent 2000: 83: 540-547 https://doi.org/10.1016/S0022-3913(00)70012-6
  32. Kato H. Matsumura H. Tanaka T, Atsuta M. Bond strength and durability of porce-lain bonding systems. J Prosthet Dent 1996: 75: 163-168 https://doi.org/10.1016/S0022-3913(96)90094-3
  33. Rosentritt M, Plein T, Kolbeck C, Behr M, Handel G. In vitro fracture force and marginal adaptation of ceramic crowns fixed on natural and artificial teeth. Int J Prosthodont 2000: 13: 387-391
  34. Kern M, Fechtig T, Strub JR. Influence of water storage and thermal cycling on the fracture strength of all-porcelain, resinbonded fixed partial dentures. J Prosthet Dent 1994:71:251-256 https://doi.org/10.1016/0022-3913(94)90463-4