Late discolouration of root-treated teeth and subsequent restorative retreatment: three case reports.

Root-filled teeth that receive ceramic veneers may experience subsequent coronal discolouration, which will likely negatively affect the quality of life of patients and their relationship with the clinician. This manuscript describes three cases of this undesirable aesthetic consequence in anterior teeth of young patients and the subsequent restorative reintervention, with satisfactory results. In all three reports, the root canal filling was performed using cements containing bismuth oxide that likely disassociated into reduced metallic crystals when in contact with LED light. The discolouration observed after veneer cementation was most likely caused by the accumulation of these bismuth metallic crystals. These cases highlight the importance of preventing this undesirable complication, which may also result in the potential subsequent further sacrifice of sound coronal dental structure, and the role of recall in aesthetically demanding clinical cases.

Shade evaluation of ceramic laminates according to different try-in materials.

The porcelain laminate replaces the visible portion of enamel with a ceramic, which is attached to the dental surface. To enhance cosmetic results, a preliminary color matching procedure is performed prior to cementing the veneers. This procedure can be performed using water, water-soluble gel, or try-in paste. The different shades of cement and try-in pastes are intended to obtain better color and esthetics of the final restoration. This study sought to evaluate the shade of ceramic veneers produced by different try-in materials. Forty bovine teeth and 40 ceramic discs (0.6 mm thick) were prepared. The samples were divided into 4 groups (n = 10). For Group 1 samples, no material was used between the tooth and the ceramic, Group 2 interposed samples with water, Group 3 used a water-soluble gel, and Group 4 used try-in paste (value 0). The color was measured with a spectrophotometer, obtaining L*, a*, and b* values to calculate the color difference (ΔE*). The data were subjected to normality tests and 1-way ANOVA. No significant statistical differences were found among the groups, indicating that the different try-in materials had similar effects on the color of the ceramic laminates.