In vivo and in vitro spectrophotometric evaluation of upper central incisors before and after extraction.

OBJECTIVES: This in vivo and in vitro study investigated the influence of pulpal vitality on the optical properties of teeth over a 1-month period. MATERIALS AND METHODS: We monitored two specific areas (2-mm-thick pure enamel and 3-mm-thick enamel-dentine complex) in 10 teeth against two backgrounds (white and black) using a calibrated reflectance spectrophotometer at the following time points: before extraction (T0); immediately after extraction (T1); at 1-day post-extraction (T2); at 1-week post-extraction (T3); and 1-month post-extraction (T4). We recorded tooth colour based on the Commission Internationale d'Eclairage L*a*b* model and translucency and analysed these characteristics over time using analysis of variance. RESULTS: The 2-mm-thick pure enamel area showed significant changes (p > 0.05) in L*, a* and b* values between before and 1 month after extraction (T0-T4). Translucency was detectable between (T0-T3) and (T0-T4). The 3-mm-thick enamel-dentine complex also exhibited significant differences (p > 0.05) in L*, a* and b* values within (T0-T4). Translucency value changes significantly (p > 0.05) within the first day (T0-T2) and (T0-T3). CIEDE 2000 DE values revealed no statistically significant differences (p < 0.05) in colour between the T0 L*a*b* measures and all the subsequent measures at times T1, T2, T3 and T4. CONCLUSIONS: Within the limitations of this study, we conclude that the optical characteristics (i.e. colour and translucency) of teeth change after extraction. CLINICAL RELEVANCE: The results help understanding the precise moment when the colour of extracted tooth changes to identify optimum time to use a tooth for scientific investigation and determine whether it is necessary to extract pulp tissue beforehand.