Crown Discoloration Induced by Endodontic Sealers: Spectrophotometric Measurement of Commission International de I'Eclairage's L*, a*, b* Chromatic Parameters

Abstract

Despite the improvement of endodontic materials, crown discoloration induced by root canal sealers remains a concerning clinical issue. The aim of this study is the measurement of the alterations in CIE L*, a*, b* chromatic parameters of tooth crowns after placement of commonly used and new-generation endodontic sealers in pulp chambers. Eighty intact, fully developed third mandibular molars were randomly assigned in five groups. Crowns were cross-sectioned from the root complex 1 mm below the cement-enamel junction. The internal axial walls of the pulp chambers were debrided and coated with endodontic sealers (Roth-811, AH-26, Guttaflow, Epiphany SE). The apical access was sealed with glass-ionomer cement. The control group was only debrided. Crowns were stored in individually marked vials in standard conditions (100% humidity, 37°C). The spectral reflectance lines were recorded with a UV-Vis spectrophotometer in the visual spectrum. The CIE L*a*b* parameters were obtained by a linked computer software before sealer placement (baseline), after one week, one, three, and six months, respectively. Statistical analysis was performed with two-way mixed ANOVA models. The level of statistical significance was set at p<0.05. With the exception of the control group, experimental groups presented varying chromatic alterations. Among all experimental groups, Roth-811 sealer induced the most severe alterations in CIE L*, a*, b* chromatic parameters, during all observation periods. After root canal obturation, the clinician should be aware of the presence of remaining root canal filling materials. Thorough debridement of the pulp chamber is essential for the prevention of sealer-induced discoloration.