Objective: The aim of this in vitro study was to evaluate the effects of substrate colors, different levels of ceramic thickness and translucency, and cement shades on the color difference from a reference color of lithium‐disilicate crowns.Materials and Methods: A premolar tooth preparation was made on a study model for 1.0 and 1.5 mm thick full‐ceramic crowns. Digital impressions were taken (3Shape TRIOS) and crowns designed in a CAD program (DentalDesigner). Shade A1 crowns were milled (Everest, Kavo) from high‐translucency (HT) and low‐translucency IPS e.max (Ivoclar Vivadent) blocks. Twelve substrates were made of different colors and materials (Natural Die Material, Co‐Cr, zirconia, and gold‐colored alloy). Three different shades of try‐in pastes were used to simulate the effect of cements (Variolink Esthetic try‐in paste; Ivoclar). Shade measurement was done three times for each crown by a spectrophotometer (VITA Easyshade Advance); averages were compared to a reference crown (A1, HT, 1.5 mm, ND2 abutment, neutral try‐in paste) with ΔE00 (CIEDE2000, according to the CIE latest standard) calculated.Results: All the examined parameters influenced the ΔE00 of the crowns. The weakest effect was exerted by the try‐in paste.Conclusions: All examined parameters influenced the final color of e.max CAD lithium‐disilicate ceramic crowns.Clinical Significance: Matching the shade of ceramic crowns to the natural tooth color is a great challenge in dentistry. To meet patients' increasing esthetical expectations, CAD/CAM methods are very popular for full‐ceramic crowns. However, several factors such as the shade of the abutment, luting cement color, ceramic thickness, and translucency may influence the final color. Our objective was to measure the optical effect of these factors on the final shade of CAD/CAM lithium‐disilicate ceramic crowns.
Objective: The aim of this study was to investigate the later oral consequences of chemotherapy on the oral health of children with emphasis on the cariological status and the major and minor salivary gland function. Method: Thirty-eight 12-year-old children (mean age 12.3 ± 0.58 years) who underwent chemotherapy were evaluated after 5 years of treatment. Forty age- and sex-matched healthy children with similar socioeconomic backgrounds served as controls. Subjects’ cariological status was explained by the number of decayed, filled, missing permanent teeth (DMF-T), and unstimulated and stimulated whole saliva flow rates were measured by the spitting method. Palatal saliva flow rate using a Periotron meter (Oraflow Inc., Plainview, NY) and salivary buffer capacity using CRT buffer (Ivoclar Vivadent AG, Schaan, Lichtenstein) were also investigated. Results: Children who underwent chemotherapy had significantly more decayed teeth than healthy controls (3.97 ± 3.58 vs 0.84 ± 1.75, respectively, p < 0.001). Recipients of chemotherapy had significantly lower stimulated whole saliva flow rate (0.84 ± 0.35 vs 1.13 ± 0.46 ml/min, p < 0.05) compared to the controls. Palatal saliva flow rate was at the same time significantly higher in the test group compared to the controls (1.64 ± 0.87 vs 0.46 ± 0.32 ml/min/cm2, respectively, p < 0.001). High levels of buffer capacity of the saliva could be detected in a significantly higher prevalence in the patient group compared to the controls (high: 81.6% vs 40%). Conclusions: According to these results, chemotherapy in children might result in a decreased stimulated whole saliva flow rate, hyposalivation, and, consequently, increased caries risk. Although these processes might be compensated to a limited extend by the increased minor saliva flow rate, resulting in a higher buffer capacity, nutrition and oral hygiene control of children obtaining cancer therapy is essential in the preservation of the oral tissues.