Achieving the desired colour in discoloured teeth, using leucite-based CAD-CAM laminate systems.
OBJECTIVE
To evaluate the cumulative effect of the abutment tooth and resin cement colour on the resultant optical properties of porcelain laminate veneers (PLVs) fabricated with leucite-based CAD/CAM blocks with different shades and thicknesses.


METHODS
A total of 224 ceramic specimens were prepared from the IPS Empress CAD with four different shades of HT-A1, LT-A1, MT-A1 and Bl-1. Resin composite discs were prepared with shade A3.5. For the cementation, 4 different shades of light-cure resin cements were chosen. L*, a*, and b* values, as well as the chroma (C) and hue (h) values of each cemented ceramic and the A1 shade table, were recorded.


RESULTS
L*, Cab* and hab* values of the cemented ceramics were influenced by ceramic shade, ceramic thickness, cement shade, and interaction terms of the three variables. There were significant differences between the 1-mm-thick ceramic veneers that exhibited higher L* and lower Cab* values compared with veneers that were 0.5mm in thickness. Using the Tr shade cement resulted in lower L* and higher Cab* values for all thicknesses and ceramic shades, whereas the WO shade cement resulted in higher values.


CONCLUSIONS
The selected colour of a laminate restoration is significantly affected by the ceramic shade, ceramic thickness and resin cement shade. Using the WO shade resin cement seems to be more effective in masking the discoloured abutment tooth. Clinicians should also select the translucency level of the ceramic block with the shade when a leucite-based CAD/CAM system is chosen to treat a discoloured tooth.
Department of Prosthodontics, Faculty of Dentistry, Karadeniz Technical University, Trabzon, Turkey.
Sedanur
S
Turgut
Department of Prosthodontics, Faculty of Dentistry, Izmir Katip Celebi University, Izmir, Turkey. Electronic address: bbagis@yahoo.com.
Bora
B
Bagis
Department of Prosthodontics, Faculty of Dentistry, Karadeniz Technical University, Trabzon, Turkey.
Elif Aydogan
EA
Ayaz
D000538:Aluminum Silicates / Q000737:chemistry*; D003116:Color; D003124:Colorimetry / Q000295:instrumentation; D003188:Composite Resins / Q000737:chemistry; D017076:Computer-Aided Design; D000044:Dental Abutments; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003801:Dental Veneers; D006801:Humans; D008422:Materials Testing; D058105:Polymerization; D017797:Prosthesis Coloring; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D014070:Tooth / Q000473:pathology; D014075:Tooth Discoloration / Q000473:pathology / Q000534:rehabilitation
D000538:Aluminum Silicates; D003188:Composite Resins; C444701:Filtek Z250; C520133:IPS e.max CAD LT; D019279:Resin Cements; D003776:Dental Porcelain; C078519:leucite
CAD CAM; Colour; Laminate veneers