Lect.3 Esthetic operative Dentistry 4th stage -2019

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https://publons.com/researcher/1437059/ameer-hamdi-hakeem-alameedee/
http://staff.uobabylon.edu.iq/site.aspx?id=876
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Smile design and golden proportions.
Shade estimation, Color, the dimensions (Hue, Chroma, and Value).
Occlusion and Aesthetics; Principles of occlusion, Anterior guidance, Occlusal plane.
Smile design and golden proportions.
In 530BC Pythagoras suggested beauty could be defined as an exact mathematical concept, which led to the Divine or Golden proportion (1/1.618=0.618). Similarly, Plato proposed the Beautiful proportion (1/1.733=0.577) as the quintessential ratio for beauty. Both ideas stated that an object with these proportions had innate beauty. The most widely used concept in dentistry is the Golden proportion — where S is the smaller and L the larger part.

Color:
Color is a property of light. Objects have no color of their own; they just reflect a particular wavelength from the color spectrum. For example a blue object absorbs all of the wavelengths, except for blue. The remaining wavelengths enter our eyes and this is what we see. The nature of light and the eye perceives and the brain interprets light as color is important for successful esthetic restorations, particularly when metal-ceramic or all-ceramic restorations are being made. Electromagnetic waves are everywhere and light is only a small part of them. Light is basically photons and mostly moves as waves.

Color Blindness:
Color blindness is the inability to distinguish the differences between certain colors. This condition results from an absence of color-sensitive pigment in the cone cells of the retina. White light that is seen by human eye is called as “visible” light (380 nm to 780 nm). Waves called radio, microwave, infrared, ultraviolet (UV), x-rays, and gamma rays cannot be seen by the human eye. The most popular method for describing color is the Munsell system. The three attributes of color in this system are called Hue, Chroma and Value.

Hue;
Hue is the name of the color (Red, Orange, Yellow, Green, Blue, Indigo, and Violet). In the younger permanent dentition, hue tends to be similar throughout the mouth. With aging, variations in hue often occur because of intrinsic and extrinsic staining from restorative materials, foods, beverages, smoking, and other influences.