The effect of ceramic thickness and number of firings on the color of a zirconium oxide based all ceramic system fabricated using CAD/CAM technology
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PURPOSE. Ceramics have a long history in fixed prosthodontics for achieving optimal esthetics and various materials have been used to improve ceramic core strength. However, there is a lack of information on how color is affected by fabrication procedure. The purpose of this study was to evaluate the effects of various dentin ceramic thicknesses and repeated firings on the color of zirconium oxide all-ceramic system (LavaTM) fabricated using CAD/CAM technology. MATERIALS AND METHODS. Thirty disc-shaped cores, 12 mm in diameter with a 1 mm thickness were fabricated from zirconium oxide based all ceramic systems (LavaTM, 3M ESPE, St Paul, MN, USA) and divided into three groups (n = 10) according to veneering with dentin ceramic thicknesses: as 0.5, 1, or 1.5 mm. Repeated firings (3, 5, 7, or 9) were performed, and the color of the specimens was compared with the color after the initial firing. Color differences among ceramic specimens were measured using a spectrophotometer (VITA Easyshade, VITA Zahnfabrik, Bad Sa¨ckingen, Germany) and data were expressed in CIELAB system coordinates. A repeated measures ANOVA and Bonferroni post hoc test were used to analyze the data (n = 10, α=.05). RESULTS. L*a*b* values of the ceramic systems were affected by the number of firings (3, 5, 7, or 9 firings) (P<.001) and ceramic thickness (0.5, 1, or 1.5 mm) (P<.001). Significant interactions were present in L*a*b* values between the number of firings and ceramic thickness (P<.001). An increase in number of firings resulted in significant increase in L* values for both 0.5 mm and 1.5 mm thicknesses (P<.01, P=.013); however it decreased for 1 mm thickness (P<.01). The a* values increased for 1 mm and 1.5 mm thicknesses (P<.01), while it decreased for 0.5 mm specimens. The b* values increased significantly for all thicknesses (P<.01, P=.022). As the dentin ceramic thickness increased, significant reductions in L* values (P<.01) were recorded. There were significant increases in both a* and b* values (P<.01) as the dentin ceramic thickness increased. CONCLUSION. The number of firings and dentin ceramic thickness have a definite effect on the final color of all ceramic system tested. The mean ΔE value increased as the dentin ceramic thicknesses increased for zirconium-oxide based all ceramic specimens tested. However, the mean ΔE values were less than 3.7ΔE units which is rated as a match in the oral environment.
Abstract
PURPOSE. Ceramics have a long history in fixed prosthodontics for achieving optimal esthetics and various materials have been used to improve ceramic core strength. However, there is a lack of information on how color is affected by fabrication procedure. The purpose of this study was to evaluate the effects of various dentin ceramic thicknesses and repeated firings on the color of zirconium oxide all-ceramic system (LavaTM) fabricated using CAD/CAM technology. MATERIALS AND METHODS. Thirty disc-shaped cores, 12 mm in diameter with a 1 mm thickness were fabricated from zirconium oxide based all ceramic systems (LavaTM, 3M ESPE, St Paul, MN, USA) and divided into three groups (n = 10) according to veneering with dentin ceramic thicknesses: as 0.5, 1, or 1.5 mm. Repeated firings (3, 5, 7, or 9) were performed, and the color of the specimens was compared with the color after the initial firing. Color differences among ceramic specimens were measured using a spectrophotometer (VITA Easyshade, VITA Zahnfabrik, Bad Sa¨ckingen, Germany) and data were expressed in CIELAB system coordinates. A repeated measures ANOVA and Bonferroni post hoc test were used to analyze the data (n = 10, α=.05). RESULTS. L*a*b* values of the ceramic systems were affected by the number of firings (3, 5, 7, or 9 firings) (P<.001) and ceramic thickness (0.5, 1, or 1.5 mm) (P<.001). Significant interactions were present in L*a*b* values between the number of firings and ceramic thickness (P<.001). An increase in number of firings resulted in significant increase in L* values for both 0.5 mm and 1.5 mm thicknesses (P<.01, P=.013); however it decreased for 1 mm thickness (P<.01). The a* values increased for 1 mm and 1.5 mm thicknesses (P<.01), while it decreased for 0.5 mm specimens. The b* values increased significantly for all thicknesses (P<.01, P=.022). As the dentin ceramic thickness increased, significant reductions in L* values (P<.01) were recorded. There were significant increases in both a* and b* values (P<.01) as the dentin ceramic thickness increased. CONCLUSION. The number of firings and dentin ceramic thickness have a definite effect on the final color of all ceramic system tested. The mean ΔE value increased as the dentin ceramic thicknesses increased for zirconium-oxide based all ceramic specimens tested. However, the mean ΔE values were less than 3.7ΔE units which is rated as a match in the oral environment.
참고문헌 (41)
- Piconi C, "Zirconia as a ceramic biomaterial", Biomaterials, 20, pp.1~25 (1999)
- Meyenberg KH, "Zirconia posts: a new allceramic concept for nonvital abutment teeth", J Esthet Dent, 7, pp.73~80 (1995)
- Derand T, "Bond strength of composite luting cement to zirconia ceramic surfaces", Dent Mater, 21, pp.1158~1162 (2005)
- Wohlwend A, "The zirconium oxide abutment: an all-ceramic abutment for the esthetic improvement of implant superstructures", Quintessence Dent Technol, 1, pp.63~74 (1997)
- Keith O, "Zirconia brackets: an evaluation of morphology and coefficients of friction", Am J Orthod Dentofacial Orthop, 106, pp.605~614 (1994)
- Christel P, "Mechanical properties and short-term in-vivo evaluation of yttrium-oxidepartially-stabilized zirconia", J Biomed Mater Res, 23, pp.45~61 (1989)
- Luthardt RG, "Zirconia-TZP and aluminaadvanced technologies for the manufacturing of single crowns", Eur J Prosthodont Restor Dent, 7, pp.113~119 (1999)
- Seghi RR, "Spectrophotometric analysis of color differences between porcelain systems", J Prosthet Dent, 56, pp.35~40 (1986)
- Judd DB, "Color in business, science and industry. 3rd ed", pp.105~122 (1975), John Wiley & Sons
- Heffernan MJ, "Relative translucency of six all-ceramic systems. Part II: core and veneer materials", J Prosthet Dent, 88, pp.10~15 (2002)
- Isgro｀ G, "The influence of the veneering porcelain and different surface treatments on the biaxial flexural strength of a heat-pressed ceramic", J Prosthet Dent, 90, pp.465~473 (2003)
- Dozic｀ A, "The influence of porcelain layer thickness on the final shade of ceramic restorations", J Prosthet Dent, 90, pp.563~570 (2003)
- Mclean JW, "New dental ceramics and esthetics", J Esthet Dent, 7, pp.141~149 (1995)
- Wee AG, "Variation in color between intended matched shade and fabricated shade of dental porcelain", J Prosthet Dent, 87, pp.657~666 (2002)
- Kingery WD, "Introduction to ceramics. 2nd ed", pp.646~689 (1976), John Wiley & Sons
- Heffernan MJ, "Relative translucency of six all-ceramic systems. Part I: core materials", J Prosthet Dent, 88, pp.4~9 (2002)
- Kelly JR, "Ceramics in dentistry: historical roots and current perspectives", J Prosthet Dent, 75, pp.18~32 (1996)
- Seghi RR, "Relative flexural strength of six new ceramic materials", Int J Prosthodont, 8, pp.239~246 (1995)
- Wagner WC, "Biaxial flexural strength and indentation fracture toughness of three new dental core ceramics", J Prosthet Dent, 76, pp.140~144 (1996)
- Giordano RA, "Dental ceramic restorative systems", Compend Contin Educ Dent, 17, pp.779~782 (1996)
- CIE (Commission Internationale de l’Eclairage), "Colorimetrytechnical report. 3rd ed" (2005), Bureau Central de la CIE. CIE Publication No. 15
- Seghi RR, "Visual and instrumental colorimetric assessments of small color differences on translucent dental porcelain", J Dent Res, 68, pp.1760~1764 (1989)
- Johnston WM, "Assessment of appearance match by visual observation and clinical colorimetry", J Dent Res, 68, pp.819~822 (1989)
- Ruyter IE, "Color stability of dental composite resin materials for crown and bridge veneers", Dent Mater, 3, pp.246~251 (1987)
- O'Brien WJ, "Sources of color variation on firing porcelain", Dent Mater, 7, pp.170~173 (1991)
- Hammad IA, "A qualitative study for the bond and color of ceramometals. Part II", J Prosthet Dent, 65, pp.169~179 (1991)
- Jacobs SH, "Effect of porcelain thickness and type of metal-ceramic alloy on color", J Prosthet Dent, 57, pp.138~145 (1987)
- Barghi N, "Optimum thickness of opaque and body porcelain", J Prosthet Dent, 48, pp.429~431 (1982)
- Shokry TE, "Effect of core and veneer thicknesses on the color parameters of two all-ceramic systems", J Prosthet Dent, 95, pp.124~129 (2006)
- Jorgenson MW, "Spectrophotometric study of five porcelain shades relative to the dimensions of color, porcelain thickness, and repeated firings", J Prosthet Dent, 42, pp.96~105 (1979)
- Douglas RD, "Predicting porcelain thicknessrequired for dental shade matches", J Prosthet Dent, 82, pp.143~149 (1999)
- Antonson SA, "Contrast ratio of veneering and core ceramics as a function of thickness", Int J Prosthodont, 14, pp.316~320 (2001)
- Lee YK, "Layered color of all-ceramic core and veneer ceramics", J Prosthet Dent, 97, pp.279~286 (2007)
- Barghi N, Goldberg, "Porcelain shade stability after repeated firing", J Prosthet Dent, 37, pp.173~175 (1977)
- Barghi N, "A study of various factors influencing shade of bonded porcelain", J Prosthet Dent, 39, pp.282~284 (1978)
- Uludag B, "The effect of ceramic thickness and number of firings on the color of ceramic systems: an in vitro study", J Prosthet Dent, 97, pp.25~31 (2007)
- Ozturk O, "The effect of ceramic thickness and number of firings on the color of two all-ceramic systems", J Prosthet Dent, 100, pp.99~106 (2008)
- Knispel G, "Factors affecting the process of color matching restorative materials to natural teeth", Quintessence Int, 22, pp.525~531 (1991)
- Crispin BJ, "Effect of different metal ceramic alloys on the color of opaque and dentin porcelain", J Prosthet Dent, 65, pp.351~356 (1991)
- Mulla FA, "Effects of temperature on color stability of porcelain stains", J Prosthet Dent, 65, pp.507~512 (1991)
- Lund PS, "Color changes of porcelain surface colorants resulting from firing", Int J Prosthodont, 5, pp.22~27 (1992)