Bovine Tooth Discoloration Induced by Endodontic Filling Materials for Primary Teeth

Abstract

Objective. This study evaluated the discoloration potential of endodontic materials used in primary teeth. Material and Methods. Dentine-enamel blocks were prepared from 75 bovine teeth, assorted in five experimental groups (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>n</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">15</mml:mn></mml:math>). The tested materials included an MTA-based material; zinc oxide and eugenol cement (ZOE); Vitapex; and calcium hydroxide thickened with zinc oxide (Calen + ZO). The color measurements were performed using a spectrophotometer at the following intervals: prior to (T0) and after placement of the filling (T1) and after 1 week (T2), 1 month (T3), 3 months (T4), 6 months (T5), and 9 months (T6). Data were submitted to ANOVA with repeated measures and Tukey’s test. Results. The time had a significant effect on the color variation (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi mathvariant="normal">Δ</mml:mi><mml:msubsup><mml:mrow><mml:mi>E</mml:mi></mml:mrow><mml:mrow><mml:mn fontstyle="italic">00</mml:mn></mml:mrow><mml:mrow><mml:mo>⁎</mml:mo></mml:mrow></mml:msubsup></mml:math>) (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.0001</mml:mn></mml:math>). The effect of the materials on the color variation (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mi mathvariant="normal">Δ</mml:mi><mml:msubsup><mml:mrow><mml:mi>E</mml:mi></mml:mrow><mml:mrow><mml:mn fontstyle="italic">00</mml:mn></mml:mrow><mml:mrow><mml:mo>⁎</mml:mo></mml:mrow></mml:msubsup></mml:math>) was statistically significant (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.004</mml:mn></mml:math>). Interactions between time and materials demonstrated a significant effect on the values (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mi mathvariant="normal">Δ</mml:mi><mml:msubsup><mml:mrow><mml:mi>E</mml:mi></mml:mrow><mml:mrow><mml:mn fontstyle="italic">00</mml:mn></mml:mrow><mml:mrow><mml:mo>⁎</mml:mo></mml:mrow></mml:msubsup></mml:math>) (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.0001</mml:mn></mml:math>). The ZOE cement showed the highest darkening effect (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M8"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.018</mml:mn></mml:math>). Conclusion. The MTA-based material showed the smallest discoloration during the experimental time; however, it was similar to the other materials and to the control group. Zinc oxide and eugenol showed higher discoloration.