Effect of calcium silicate-based endodontic sealers on tooth color: A 3-year in vitro experimental study

OBJECTIVE: To analyze the change in tooth color produced by two hydraulic and one resin-based sealers by means of spectrophotometry for 3 years. METHODS: Forty maxillary anterior teeth were selected (n = 10 per group). Root canals were prepared by rotary instrumentation and irrigation was performed with NaOCl, which was also used in the final irrigation, followed by saline and activated with Endoactivator. Root canals were then filled using single cone technique. Negative control (NC): gutta-percha filling; Positive control: gutta-percha and AH Plus; experimental groups: gutta-percha and Bioroot RCS/TotalFill BC Sealer. Gutta-percha was cut 2 mm below the cementoenamel junction, the pulp chamber was sealed with flowable composite. The teeth were kept in PBS. Color was measured in the cervical and incisal halves before root canal treatment (RCT), one and six months after RCT, and after one, two and three years, with the Vita EasyShade spectrophotometer; positioned using an individualized splint. ΔE(ab) and ΔE(00) were calculated. Two-way ANOVA repeated measures test followed by Bonferroni post-test were performed to analyze the ΔL, Δa*, Δb*, ΔE(ab), and ΔE(00), considering treatment groups and evaluation periods. Statistical significance was set at p < 0.05. RESULTS: In the incisal half, in decreasing order of darkening, the groups at three years were ordered according to the ΔE(ab): AH Plus > NC > TotalFill > Bioroot. ΔE(00) values were: 1.38 ± 0.61 NC, 2.37 ± 0.70 AH Plus, 1.86 ± 0.60 BioRoot and 1.53 ± 0.85 TotalFill. In the cervical half, the ΔE(ab) values, showed the same descending order, except for Bioroot and TotalFill which alternated the order. The ΔE(00) values were 1.86 ± 0.61 NC, 3.01 ± 0.70 AH Plus,1.89 ± 0.58 Bioroot and 1.65 ± 0.41 TotalFill, with no significant differences between groups and times in both locations. CONCLUSIONS: All groups presented some degree of discoloration. Lightness and b* component were the most influential. Calcium silicate-based cements (Bioroot RCS and TotalFill BC Sealer) produced acceptable levels of discoloration at the end of follow-up.