Dental and Medical Problems

Dent Med Probl
Index Copernicus (ICV 2021) – 132.50
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ISSN 1644-387X (print)
ISSN 2300-9020 (online)
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Dental and Medical Problems

2016, vol. 53, nr 2, April-June, p. 230–235

doi: 10.17219/dmp/62196

Publication type: original article

Language: English

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Creative Commons BY-NC-ND 3.0 Open Access

Flexural Properties of Chairside CAD/CAM Materials

Własności sprężyste materiałów CAD/CAM w warunkach gabinetu stomatologicznego

Rania El-Saady Badawy1,A,B,C,D, Omar El-Mowafy2,A,B,C,D,E,F, Laura Tam2,A

1 Faculty of Dentistry, Suez Canal University, Ismailia, Egypt

2 Department of Clinical Sciences, Faculty of Dentistry, University of Toronto, Canada


Background. New blocks for milling crowns using CAD-CAM technology were introduced to the profession. It is important to determine mechanical properties of such materials since they are used for the fabrication of crowns used in stress-bearing areas.
Objectives. This study determined the flexural strength (FS) and the flexural modulus (FM) of 2 glass-ceramic and 2 nanoceramic resin composite CAD/CAM blocks used for chair-side crown fabrication
Material and Methods. Rectangular specimens were cut from 4 different CAD-CAM blocks. Specimens were 3 mm wide, 1.2 mm thick 14 mm long. Specimens were subjected to 3-point bending test following ISO guidelines (ISO 6872) at cross-head speed of 0.5mm/min. The flexural strength (FS) and the flexural modulus (FM) were calculated and the data statistically-analyzed with one-way ANOVA and Games Howell multiple comparison tests at 95% confidence interval.
Results. Means and SDs of FS (MPa) for VE, LU, E-max, E-max-U, CD, CD-U were: 123.97(14.84), 168.07(16.70), 334.10(54.3), 128.90(17.6), 177.32(37.54) and 147.61(26.62) respectively. For FM means and SDs were: 17.18(2.03), 9.75(0.51), 44.8(5.52), 35.14(7.46), 32.96(6.55) and 38.90(8.03) for VE, LU, E-max, E-max-U, CD, CD-U, respectively. ANOVA revealed a highly significant difference among group means (p < 0.0001) for both FS and FM. E-max had significantly highest mean FS and FM values among all groups, while VE showed lowest FS and LU lowest FM means. Firing and or crystallization positively affected both flexural properties of E-max, but only FS of CD.
Conclusion. A wide variability in mean FS and FM was observed among the tested materials. Generally, glassceramic based materials had superior flexural properties.

Key words

flexural modulus, flexural strength, flexural properties of milling blocks

Słowa kluczowe

moduł sprężystości, wytrzymałość na zginanie, właściwości sprężyste wyfrezowanych klocków

References (45)

  1. Albakry M., Guazzato M., Vincent Swain M.: Effect of sandblasting, grinding, polishing and glazing on the flexural strength of two pressable all-ceramic dental materials. J. Dent. 2004, 32, 91–99.
  2. Cattel M.J., Clarke R.L., Lynch E.J.R.: The transverse strength, reliability and microstructural fatures of four dental ceramics-Part I. J. Dent. 1997, 25, 399–407.
  3. Yilmaz H., Aydin C., Gul B.E.: Flexural strength and fracture toughness of dental core ceramics. J. Prosthet. Dent. 2007, 98, 120–128.
  4. Borba M., De Araújo M., De Lima E., Yoshimura H.N., Cesar P.F., Griggs J.A., Della Bona A.: Flexural strength and failure modes of layered ceramic structures. Dent. Mater. 2011, 27, 1259–1266.
  5. Mörmann W.H.: The evolution of the CEREC system. J.A.D.A. 2006, 137, 7S – 13S.
  6. O’Brien W.J.:Dental materials and their selection. Dental materials and their selection. 3rd ed. Quint. Pub. 2002, p: 210–224.
  7. Strub J.R., Beschnidt S.M.: Fracture strength of five different all-ceramic crown systems. Int. J. Prosthodont. 1998,11, 602–609.
  8. Kelly J.R.: Perspectives on strength. Dent. Mater. 1995, 11, 103–110.
  9. Shareef M.Y., Van Noort R., Messer P.F.: The effect of microstructural features on the biaxial flexural strength of leucite reinforced glass-ceramics. J. Mater. Sci. Mater. Med. 1994, 5, 113–118.
  10. Borba M., de Araujo M.D., Fukushima K.A., Yoshimura H.N., Cesar P.F., Griggs J.A., Della Bona A.: Effect of the microstructure on the lifetime of dental ceramics. Dent. Mater. 2011, 27, 710–721.
  11. Denry I.L.: Recent advances in ceramics for dentistry. Crit. Rev. Oral. Biol. Med. 1996, 7, 134–143.
  12. Jager N., Feilzer A.J., Davidson C.L.: The influence of surface roughness on porcelain strength. Dent. Mater. 2000, 16, 381–388.
  13. Guazzato M., Albakry M., Ringer S.P., Swain M.V.: Strength, fracture toughness and microstructure of a selection of all-ceramic materials. Part II. Zirconia-based dental ceramics. Dent. Mater. 2004, 20, 449–456.
  14. Guazzato M., Albakry M., Ringer S.P., Swain M.V.: 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.
  15. Zeng K., Oden A., Rowcliffe D.: Flexure tests on dental ceramics. Int. J. Prosthodont. 1996, 9, 434–439.
  16. Guazzato M., Quach L., Albakry M., Swain M.V.: Influence of surface and heat treatments on the flexural strength of Y-TZP dental ceramic. J. Dent. 2005, 33, 9–18.
  17. Quinn G. D., Morrell R.: Design data for Engineering Ceramics : A review of the flexure test. J. Am. Ceram. Soc. 1991, 74, 2037–2066.
  18. Fairthrust C.W., Lockwood P.E., Ringle R.D. Thompson W.O.: The effect of glaze on porcelain strength. Dent. Mater. 1992, 8, 203–207.
  19. Ban S., Anusavice K.J.: Influence of test method on failure stress of brittle dental materials. J. Dent. Res. 1990, 69, 1791–1799.
  20. Arita K., Lucas M.E., Nishino M.: The effect of adding hydroxyapatite on the flexural strength of glass ionomer cement. Dent. Mater. J. 2003, 22, 126–136.
  21. Sailer I., Feher A., Filser F., Gauckler L.J., Luthy H., Hammerle C.H.: Five year clinical results of zirconia frameworks for posterior fixed partial dentures. Int. J. Prosthodont. 2007, 20, 383–388.
  22. Jin J., Takahashi H., Iwasaki N.: Effect of test method on flexural strength of recent dental ceramics. Dent. Mater. J. 2004, 23, 490–496.
  23. White S.N., Miklus V.G., Mc Laren E.A., Lang L.A., Caputo A.A.: Flexural strength of a layered zirconia and porcelain dental all ceramic systems. J. Prosthet. Dent. 2005, 94, 125–131.
  24. Pallis K., Griggs J.A., Woody R.D., Guillen G.E., Miller A.W.: Fracture resistance of three all-ceramic restorative systems for posterior applications. J. Prosthet. Dent. 2004, 91, 561–569.
  25. Ritter E.: Predicting lifetimes of materials and material structures. Dent. Mater. 1995, 11, 142–146.
  26. Apholt W., Bindl A., Luthy H., Mörmann W.H.: Flexural strength of Cerec 2 machined and joined In-Ceram Alumina and In-Ceram Zirconia bars. Dent. Mater. 2001, 17, 260–267.
  27. Thornton I.: Mechanical properties of dental resin composite CAD/CAM blocks. 2014.
  28. Guess P.C., Schultheis S., Bonfante E.A., Coelho P.G., Ferencz J.L., Nelson R.F.A.: All-ceramic systems: Laboratory and clinical performance. Dent. Clin. North. Am. 2011, 55, 333–352.
  29. Hoeland W., Apel E., van’t Hoen Ch., Rheinberger V.: Studies of crystal phase formation in the early stage crystallization of lithium disilicate glass ceramics. J. Non-Cryst. Solids. 2006, 352, 4041–4050.
  30. Fischer H., Dautzenberg G., Marx R.: Non-destructive estimation of the strength of dental ceramic materials. Dent. Mater. 2001, 17, 289–295.
  31. Tinschert J., Natt G., Mautsch W., Augthun M., Siekermann H.: Fracture resistance of lithiumdisilicate, alumina-, and zirconia-based three-unit fixed partial dentures: A laboratory study. Int. J. Prosthod. 2001, 14, 231–238.
  32. Vaslylkiv O., Sakka Y., Skorokhod V.V.: Low-temperature processing and mechanical properties of zirconia and zirconia-alumina nanoceramics. J. Am. Ceram. Soc. 2003, 86, 299–304.
  33. Sazaki K., Nakano M., Mimurada J., Ikuhara Y., Sakuma T.: Strain hardening in superplastic codeped Yttriastabilized tetragonal zirconia polycrystals. J. Am. Ceram. Soc. 2001, 84, 2981–2986.
  34. Nihara K.: New design concept of structural ceramics-ceramic naocomposite. J. Ceram. Soc. Jpn. 1991, 99, 974–982.
  35. Kon M., Kawano F., Asaoka K., Matsumoto N.: Effect of leucite crystals on the strength of glassy porcelain. Dent. Mater. J. 1994, 13, 138–147.
  36. Mörmann W.H, Stawarczyk B., Ender A., Sener B., Attin T., Mehl A.: Wear characteristics of current aesthetic dental restorative CAD/CAM materials: two-body wear, gloss retention, roughness and Martens hardness. J. Mech. Behav. Biomed. Mater. 2013, 20, 113–125.
  37. Mohsen C.: Corrosion effect on the flexural strength and micro-hardness of IPS e-max ceramics. Open. J. Stomatol. 2011, 1, 29–35.
  38. Nguyen J.F., Ruse D., Phan A.C., Sadoun M.J.: High-temperature-pressure polymerized resin-infiltrated ceramic networks. J. Dent. Res. 2014, 93, 62–67.
  39. Coldea A., Swain M.V., Thiel N.: Mechanical properties of polymer-infiltrated-ceramic-network materials. Dent. Mater. 2013, 29, 419–426.
  40. Della Bona A., Corazza P.H., Zhang Y.: Characterization of a polymer-infiltrated ceramicnetwork material. Dent. Mater. 2014, 30, 564–569.
  41. Ilie N., Hickel R.: Investigations on mechanical behaviour of dental composites. Clin. Oral. Investig. 2009, 13, 427–438.
  42. Lauvahutanon S., Takahashi H., Shiozawa M., Iwasaki N., Asakawa Y., Oki M., Finger W.J., Arksornukit M.: Mechanical properties of composite resin blocks for CAD/CAM. Dent. Mater. J. 2014, 33, 705–710.
  43. DeLong R., Douglas W.H.: Development of an artificial oral environment for the testing of dental restoratives: Bi-axial force and movement control. J. Dent. Res. 1983, 62, 32–36.
  44. Mihali S., Bortun C., Bratu E.: Nano-ceramic particle reinforced composite-Lava Ultimate CAD/CAM restorative. Rev. Chem. 2013, 64, 435–437.
  45. Mackert Jr. J.R., Williams A.L.: Microcracks in dental porcelain and their behavior during multiple firing. J. Dent. Res. 1996, 75, 1484–1490.