Digital Tools for Translucence Evaluation of Prosthodontic Materials: Application of Kubelka-Munk Theory

Abstract

Translucency is one of the most important parameters to be considered by digital systems when predicting the matching appearance and hence the quality of prosthodontic restoration work. Our objective has been to improve the effectiveness of the algorithmic decision systems employed by these devices by (a) determining whether Kubelka-Munk theory can be used as an algorithm for predicting restoration suitability, and (b) evaluating the correlation between the visual evaluation of prosthodontic materials and the predicted translucency based on the use of the ΔE*, OP, CR, and K/S algorithms. In this regard, three zirconia systems and one lithium disilicate have been spectrophotometrically and visually characterized. Based on the results of this study, it has been proven that zirconia systems and lithium disilicate systems exhibit different optical behaviors. The psychophysical experience suggests that none of the existing mathematical methods can adequately estimate translucency, spectrophotometric, and colorimetric techniques, and that which is perceived by an experienced observer. However, translucency evaluation through the K/S algorithmic decision system should not be disregarded. New methods to measure translucency should be developed to improve digital systems for prosthodontic applications.

Laser-tissue interaction of pump-probe elastography (PPE) on human teeth

“…A closer look at the graphs in 5A and B reveal dips at 520 nm and 650 nm, which are shown by literature for zircon ceramics. 13 The graphs in 5B and D also show specific behavior between 900 nm and 1000 nm. Figure 6 show the reflection of the human teeth measured with the HSI system.…”