Forschungsinformationssystem Universität Greifswald

Bratner S, Hannak W, Boening K, Klinke T*¹

1 - Zentrum für Zahn-, Mund- und Kieferheilkunde / Poliklinik für Zahnärztliche Prothetik, Alterszahnheilkunde und Medizinische Werkstoffkunde

ABSTRACT Objective: Visual color determination in clinics or dental offices should take place under reproducible environmental conditions. To reduce false tooth color measurements, daylight and illumination lamps (5,000-7,500 °K) are recommended, which can be used as stationary or as mobile handheld illumination units. However, depending on the manufacturer, the hand-held lights use different illuminance levels. Purpose: The purpose of this study was that neither of both handheld illuminations shows a significantly better result of the visual color determination (null hypothesis). Material and Methods: Trained students of the preclinical semester (N=23) with a mean age of 24 (+/- 5 years) years participated in the study. Color differentiation lamps (Smile lite 1,620 lx (SL), Dialite Color (DC) 1,900 lx (at 15cm each)) were used for color determination of shade tabs (templates, N=10) with the VITA Linear Guide 3D Master in a double-blinded study, according to the manufacturer’s recommendation, a polarization filter for SL was used. Results: Out of N=230 cases each, 31.8% (SL) and 33.2% (DC) of the color determinations were correct, the median (ΔE00) and interquartile range were 0.96 (+/- 3.32) for SL and 1.35 (+/- 3.28) for DC. The differences were not significant (P=.96). Thereby, illumination had only a small effect with d=0.03 (Cohen's d) and r=0.04 (normative values of Gingiac and Szodorai) in color brightness’ determination (L*). Conclusions: The results showed that the illumination difference of the used handheld illumination units had no significant effect on the color determination results, neither the different illumination intensities of 540 lx (SL, with polarization filter) nor 1,900 lx (DC) did not impact the results of tooth color differentiation. However, the results showed that the determination results were better in the darker or lighter color range than in the middle color range. Clinical Significance: The challenge of correct tooth shade determination is inherent in many dental reconstructive and restorative procedures. For visual tooth shade determination, the ambient lighting must permit color-neutral illumination to detect shade deviations, which should be as small as possible. Large deviations lead to patient dissatisfaction and possible expensive remakes. The study compares the results of color differentiation obtained under two types of illumination intensities.