SELECTION OF ANTERIOR TEETH.

1.LENGTH

THE HEIGHT OF OCCLUSAL PLANE ACCORDING TO THE LENGTH OF THE UPPER LIP.

HIGH LIP LINE LOW LIP LINE

HIGH LIP LINE LOW LIP LINE

THE AMOUNT OF UPPER TEETH SHOWING BELOW THE UPPER LIP DEPENDS ON: LENGTH OF UPPER LIP. MOBILITY OF THE UPPER LIP. VERTICAL HEIGHT OF OCCLUSION.

2. WIDTH

Size: Width: **Width of the six maxillary anteriors is slightly less than one third of the bizygomatic width. **The width of the natural central incisor,1, approximately 1/16 the bizygomatic width of the patient’s face.

**A vertical line extending along the lateral surface of the ala often will pass through the middle of the natural upper canine. CANINE LINES

Distance between the 2 canine lines = MD width of the six anterior teeth

A LINE PERPENDICUAR TO THE MIDLINE, PASSING THROUGH THE POSTERIOR BORDER OF THE INCISIVE PAPILLAE. CANINE POSITION ON THE CAST.

Outline form of the face should be in harmony The shape of the upper central incisors should be in harmony with the shape of the face. OVOIDTAPERED SQUARE

SQUARED OVOID TAPERED

Shape of the arch form * The shape of the teeth should be in harmony with the shape of the arch SQUARED TAPERED (V- shaped) OVOID

Shade (color ) of the teeth For the selection of the color of the anterior teeth a shade guide is used

► Selection of a suitable shade depends on: Age of the patient. Color of the patients’ face. Patients’ general complexion. Patients’ personal approval.

► The shade of a tooth is a composite of 4 qualities: ► Hue ► Saturation ► Brilliance ► Translucency

Hue: Is referred to as the basic color ; the color of the tooth is basically yellow. Saturation: the amount of hue (color) / unit area ; (Chroma) color intensity.

Brilliance: the degree of black (darkness) and white (Value) (lightness) areas of an object. Should be graduated with age. Translucency: it’s the property of an object that permits the passage of light through it but does not give a distinguishable image…makes the teeth look ALIVE.

Characteristics of natural teeth 1.The neck has a more pronounced color than the incisal edge. 2.The incisal edge is more translucent than the body because it is composed mainly of enamel. 3.Upper central incisors are the lightest teeth in the mouth.

Characteristics of natural teeth 4. Upper laterals, lower centrals and laterals are slightly darker. 5. Upper and lower canines are darker. 6. Teeth darken slightly with age.

Tooth material Artificial teeth may be made of: Artificial teeth may be made of: 1. Acrylic resin 2. Porcelain 3. Metal 4. Combination between acrylic resin and metal 5. Cross-linked acrylic resin. 6.A mix of composite and resin.

Acrylic resin teeth Properties of acrylic resin teeth: 1.Low sp. Gravity 2.Chemical union with acrylic denture bases 3.Less noisy 4.Easily modified by grinding 5.Less harmful to the underlying tissues due to their resiliency 6.Low abrasion resistance 7.Can be used in small inter-arch distance

Porcelain teeth They need mechanical means of retention pins for anterior teeth and holes for posterior teeth

Properties of porcelain teeth 1.Mechanical means of retention 2.Heavier in weight 3.Noisy in use 4.Cant be modified 5.High abrasion resistance 6.Very brittle