Table 1. Treatment attributes and its levels.

Attribute	Definition	Levels
1. Aesthetics	In terms of appearance, result of treatment individually perceived as beautiful. This attribute describes the visibility of a dental crown.	✓ Natural color ✓ Lightly visible ✓ Strongly visible
2. Compatibility	Intolerance reaction of human body due to dental material in form of an allergic or a local toxic reaction1.	✓ No risk ✓ 1 out of 10,000 people with allergic or local toxic reaction
3. Durability	Expected length of time from completion of a treatment to another new treatment that is medically or technically necessary.	✓ 5 years ✓ 10 years ✓ 15 years ✓ 25 years
4. Out-of-pocket payment	Costs that must be paid by patient for dental crown treatment. The co-payment taken by health insurance has already been subtracted here.	Posterior teeth ✓ 50 € ✓ 150 € ✓ 450 € ✓ 600 €	Anterior teeth ✓ 50 € ✓ 200 € ✓ 450 € ✓ 600 €

¹ In rare cases (1 in 10,000 people), an intolerance reaction, i.e., an allergic or local toxic reaction, may occur. Allergies are characterized by symptoms such as dry mouth, toothache, and receding gums to discomfort in the throat, lip eczema or rash on the face. Local toxic reactions are non-allergic inflammations of the oral mucosa in the immediate vicinity of the tooth crown. In the cases described, depending on the severity of the clinical symptoms, the "problematic material" must be replaced or (the dental crown) removed completely.