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Effect of abutment shade, ceramic thickness, and coping type on the final shade of zirconia all-ceramic restorations: in vitro study of color masking ability.

Oh SH, Kim SG - J Adv Prosthodont (2015)

Bottom Line: The average L*, a*, b* values of the zirconia specimens on the six abutment specimens were measured with a dental colorimeter, and the statistical significance in the effects of three variables was analyzed by using repeated measures analysis of variance (α=.05).The average shade difference (ΔE) values of the zirconia specimens between the A2 composite resin abutment and other abutments were also evaluated.The effects of zirconia specimen thickness (P<.001), abutment shade (P<.001), and type of zirconia copings (P<.003) on the final shade of the zirconia restorations were significant.The average ΔE value of Lava specimens (1 mm) between the A2 composite resin and gold alloy abutments was higher (close to the acceptability threshold of 5.5 ΔE) than th ose between the A2 composite resin and other abutments.

View Article: PubMed Central - PubMed

Affiliation: Department of Prosthodontics, Graduate School of Clinical Dental Science, The Catholic University of Korea, Seoul, Republic of Korea.

ABSTRACT

Purpose: The aim of the study was to evaluate the effect of abutment shade, ceramic thickness, and coping type on the final shade of zirconia all-ceramic restorations.

Materials and methods: Three different types of disk-shaped zirconia coping specimens (Lava, Cercon, Zirkonzahn: ø10 mm × 0.4 mm) were fabricated and veneered with IPS e.max Press Ceram (shade A2), for total thicknesses of 1 and 1.5 mm. A total of sixty zirconia restoration specimens were divided into six groups based on their coping types and thicknesses. The abutment specimens (ø10 mm × 7 mm) were prepared with gold alloy, base metal (nickel-chromium) alloy, and four different shades (A1, A2, A3, A4) of composite resins. The average L*, a*, b* values of the zirconia specimens on the six abutment specimens were measured with a dental colorimeter, and the statistical significance in the effects of three variables was analyzed by using repeated measures analysis of variance (α=.05).The average shade difference (ΔE) values of the zirconia specimens between the A2 composite resin abutment and other abutments were also evaluated.

Results: The effects of zirconia specimen thickness (P<.001), abutment shade (P<.001), and type of zirconia copings (P<.003) on the final shade of the zirconia restorations were significant. The average ΔE value of Lava specimens (1 mm) between the A2 composite resin and gold alloy abutments was higher (close to the acceptability threshold of 5.5 ΔE) than th ose between the A2 composite resin and other abutments.

Conclusion: This in-vitro study demonstrated that abutment shade, ceramic thickness, and coping type affected the resulting shade of zirconia restorations.

No MeSH data available.


Related in: MedlinePlus

ΔE values of zirconia specimens (1.5 mm thickness) between A2 resin and other shades of abutment specimens.Abbreviations; L1.5: Lava 1.5 mm, C1.5: Cercon 1.5 mm, Z1.5: Zirkonzahn 1.5 mm, BM: base metal alloy abutment, G: gold alloy abutment, A1-A4: A1-A4 shades of composite resin abutment, ΔE: shade difference.
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Figure 6: ΔE values of zirconia specimens (1.5 mm thickness) between A2 resin and other shades of abutment specimens.Abbreviations; L1.5: Lava 1.5 mm, C1.5: Cercon 1.5 mm, Z1.5: Zirkonzahn 1.5 mm, BM: base metal alloy abutment, G: gold alloy abutment, A1-A4: A1-A4 shades of composite resin abutment, ΔE: shade difference.

Mentions: In a clinical case, zirconia crowns can be placed on adjacent abutments with different shades. The type and thickness of the zirconia crowns should be determined to mask the abutment shade differences. In this study, the gold abutment (G) showed the highest L*, a*, and b* values, and other abutments showed lower values with only minute differences among themselves. It was necessary to determine whether these differences were within the acceptable range of the human eye. The shade differences (ΔE) of the zirconia specimens between the A2 resin (control: the same shade as the ceramic specimens) and other shades of abutments were compared in Fig. 5 and Fig. 6. For the 1 mmthick zirconia specimens, the ΔE value between the gold alloy and A2 resin abutments was the greatest (> 2.6). Other abutments showed minor differences (ΔE) from the A2 resin abutment, and the values were 1 or less. Lava showed the highest ΔE value (5.5) between the A2 resin and gold alloy abutments, and Zirkonzahn showed the lowest. The 1.5 mm-thick ceramic specimens had overall lower ΔE values (< 2.6 except Lava between A2 and gold) than the 1 mm-thick ones.


Effect of abutment shade, ceramic thickness, and coping type on the final shade of zirconia all-ceramic restorations: in vitro study of color masking ability.

Oh SH, Kim SG - J Adv Prosthodont (2015)

ΔE values of zirconia specimens (1.5 mm thickness) between A2 resin and other shades of abutment specimens.Abbreviations; L1.5: Lava 1.5 mm, C1.5: Cercon 1.5 mm, Z1.5: Zirkonzahn 1.5 mm, BM: base metal alloy abutment, G: gold alloy abutment, A1-A4: A1-A4 shades of composite resin abutment, ΔE: shade difference.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644777&req=5

Figure 6: ΔE values of zirconia specimens (1.5 mm thickness) between A2 resin and other shades of abutment specimens.Abbreviations; L1.5: Lava 1.5 mm, C1.5: Cercon 1.5 mm, Z1.5: Zirkonzahn 1.5 mm, BM: base metal alloy abutment, G: gold alloy abutment, A1-A4: A1-A4 shades of composite resin abutment, ΔE: shade difference.
Mentions: In a clinical case, zirconia crowns can be placed on adjacent abutments with different shades. The type and thickness of the zirconia crowns should be determined to mask the abutment shade differences. In this study, the gold abutment (G) showed the highest L*, a*, and b* values, and other abutments showed lower values with only minute differences among themselves. It was necessary to determine whether these differences were within the acceptable range of the human eye. The shade differences (ΔE) of the zirconia specimens between the A2 resin (control: the same shade as the ceramic specimens) and other shades of abutments were compared in Fig. 5 and Fig. 6. For the 1 mmthick zirconia specimens, the ΔE value between the gold alloy and A2 resin abutments was the greatest (> 2.6). Other abutments showed minor differences (ΔE) from the A2 resin abutment, and the values were 1 or less. Lava showed the highest ΔE value (5.5) between the A2 resin and gold alloy abutments, and Zirkonzahn showed the lowest. The 1.5 mm-thick ceramic specimens had overall lower ΔE values (< 2.6 except Lava between A2 and gold) than the 1 mm-thick ones.

Bottom Line: The average L*, a*, b* values of the zirconia specimens on the six abutment specimens were measured with a dental colorimeter, and the statistical significance in the effects of three variables was analyzed by using repeated measures analysis of variance (α=.05).The average shade difference (ΔE) values of the zirconia specimens between the A2 composite resin abutment and other abutments were also evaluated.The effects of zirconia specimen thickness (P<.001), abutment shade (P<.001), and type of zirconia copings (P<.003) on the final shade of the zirconia restorations were significant.The average ΔE value of Lava specimens (1 mm) between the A2 composite resin and gold alloy abutments was higher (close to the acceptability threshold of 5.5 ΔE) than th ose between the A2 composite resin and other abutments.

View Article: PubMed Central - PubMed

Affiliation: Department of Prosthodontics, Graduate School of Clinical Dental Science, The Catholic University of Korea, Seoul, Republic of Korea.

ABSTRACT

Purpose: The aim of the study was to evaluate the effect of abutment shade, ceramic thickness, and coping type on the final shade of zirconia all-ceramic restorations.

Materials and methods: Three different types of disk-shaped zirconia coping specimens (Lava, Cercon, Zirkonzahn: ø10 mm × 0.4 mm) were fabricated and veneered with IPS e.max Press Ceram (shade A2), for total thicknesses of 1 and 1.5 mm. A total of sixty zirconia restoration specimens were divided into six groups based on their coping types and thicknesses. The abutment specimens (ø10 mm × 7 mm) were prepared with gold alloy, base metal (nickel-chromium) alloy, and four different shades (A1, A2, A3, A4) of composite resins. The average L*, a*, b* values of the zirconia specimens on the six abutment specimens were measured with a dental colorimeter, and the statistical significance in the effects of three variables was analyzed by using repeated measures analysis of variance (α=.05).The average shade difference (ΔE) values of the zirconia specimens between the A2 composite resin abutment and other abutments were also evaluated.

Results: The effects of zirconia specimen thickness (P<.001), abutment shade (P<.001), and type of zirconia copings (P<.003) on the final shade of the zirconia restorations were significant. The average ΔE value of Lava specimens (1 mm) between the A2 composite resin and gold alloy abutments was higher (close to the acceptability threshold of 5.5 ΔE) than th ose between the A2 composite resin and other abutments.

Conclusion: This in-vitro study demonstrated that abutment shade, ceramic thickness, and coping type affected the resulting shade of zirconia restorations.

No MeSH data available.


Related in: MedlinePlus