Alexandra Czigola1, Emese Ábrám1, Zoltán Imre Kovács2, Péter Hermann1, Judit Borbély1
1 Semmelweis University, Faculty of Dentistry, Department of Prosthodontics, Budapest
2 Semmelweis University, Faculty of Dentistry, Department of Preclinical Practice, Budapest
Introduction: Matching the shade of ceramic crowns to the natural tooth color is a great challenge in dentistry. Meeting the patient’s growing aesthetical expectations CAD/CAM method is very popular to make full ceramic crowns. However, several factors can influence the final color of CAD/CAM lithium-disilicate ceramic crowns.
Aims: The aim of this in vitro study was to evaluate the effects of different substrate colors, different levels of ceramic thickness and translucency, and different cement shades on the final shade of lithium-disilicate crowns.
Method: A premolar tooth (14) preparation with a chamfer finishing line was made on a study model for 1.0-mm and 1.5-mm- thick full ceramic crowns. Digital impressions were taken (Trios, 3Shape) and crowns designed in a CAD program (Dental Designer) to ensure identical shape and size. Shade A1 crowns were milled (Everest, Kavo) from HT (high translucency) and LT (low translucency) IPS e.max (Ivoclar Vivadent) lithium-disilicate blocks. Twelve substrates were made of different colors and materials (nine colors of Natural Die Material, plus one each of Co-Cr, zirconia, and gold-colored alloy). Three different shades of try-in pastes were used to simulate the color effect of cements (Variolink Esthetic Try-In paste, Ivoclar). Shade measurement was done 3 times for each crown by spectrophotometer (Vita, Easyshade Advance); averages were compared to a reference crown (A1, HT, 1.5 mm, ND2 abutment, neutral try-in paste) with ΔE calculated.
Results: All of the examined parameters influenced ΔE of the crowns. The weakest effect was exerted by try-in paste.
Conclusion: Within the limitations of this study, all of the examined parameters can play an important role in changing the color of a monolithic CAD/CAM full ceramic crown.
Doctoral School: Clinical Medicine
Program: Dental Research
Supervisor: Judit Borbély
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