Translucency, opalescence and fluorescence of human teeth in relation to the storage time after extraction

The aim of the study was to analyze the translucency, opalescence, and fluorescence of enamel and dentin of extracted human teeth, as well as the influence of storage time.

Thirty-eight extracted human teeth were embedded in epoxy resin within 12 h post-extraction. After 48 h, 0.5 mm thick buccolingual sections were prepared and polished. Specimens were stored in 0.5 % chloramine T-hydrate solution at 6±1 °C. Reflectance measurements were performed using a spectrophotometer (Ci7600, X-Rite) with a round aperture (diameter: 3.5 mm) in SCI mode against black and white backgrounds. Translucency (TP_ab, TP₀₀), opalescence (OP_BW), and fluorescence (FL) were calculated for enamel and dentin separately at storage times of 7, 14, 21, and 28 days, and at three and six months.

The following values were found for human teeth: Enamel: TP_ab: 21.5-24.2 (SD: 3.5-4.3); TP₀₀: 16.8-19.4 (SD: 3.2-4.1); OP_BW: 11.2-12.5 (SD: 1.5-2.0); FL: 3.8-5.0 (SD: 1.1-1.7); Dentin: TP_ab: 15.6-17.0 (SD: 4.2-4.6); TP₀₀: 11.5-12.6 (SD: 3.3-3.5); OP_BW: 9.3-9.6 (SD: 1.9-2.5); FL: 6.0-7.5 (SD: 1.6-2.5). Storage time only had an effect on the enamel, with a significant increase (p<0.05) in TP_ab (+2.7), TP₀₀ (+2.6), and OP_BW (+1.3) observed after six months of storage.

Storage time is a significant factor for the optical properties of enamel, leading to increased translucency and opalescence after six months. In contrast, the optical properties of dentin remain largely stable.

The development and assessment of aesthetic dental materials requires a quantification of the optical properties of human teeth, as well as knowledge of influencing factors during the examination.