Teeth

requirements of the artificial teeth One of the main components of the denture are the artificial teeth. The most important requirements of the artificial teeth are the following:

Factors affecting selection of RPD teeth 1.The size, form and shade should resemble that of the remaining natural teeth. 2.Amount of available space; artificial teeth are placed within the available space incisogingival and mesiodistal 3.Mechanical properties; ; the anterior teeth selection is affected by the opposing occlusion, abrasion resistance, resistance to fracture, bond strength to denture base and ease of adjustment 4.Cusp height of opposing teeth; cusp height of the artificial teeth should be equal to or slightly different so to obtain occlusal contact 5.Condition of the supporting tissues : in distal extension base; if in distal extension base; if it is poor the occlusal forces is reduced by it is poor the occlusal forces is reduced by: a. Using a small teeth faciolingually. b. Decreasing the number of posterior teeth. c. Space teeth with diastimas. d. Sharpening of the occlusal surface to increase the masticatory efficiency. e. Using acrylic teeth.

Factors used as a guide in selection of anterior teeth form: 1-According to face form: the general outline of the tooth should conform to the general outline of the face when viewed from frontal aspect, a tooth viewed from the mesial or distal should conform to the contour of the profile.

According to face form Ovoid Square Triangular

2-According to ridge form: tooth shape may be determined upon the shape of the residual alveolar ridge

According to nose form: the shaper and position of the front teeth is established by the basal line of the nose

According to Width of the nose and face

According to age: Curved facial feature are associated with femininity, square feature are associated with masculinity According to sex: with age the teeth wear at the incisal edges and interproximal surfaces. The labial surfaces seem flatter and the outline form apperas more square

1.Law abrasion resistance. 2.May stain during use. Materials used in construction of artificial teeth 1.Acrylic denture base: Advantages:1.chemical bond with denture base resin. 2.Easily grind and polished. 3.May be used with space limited. 4.Reduce wear of opposing restorations and natural teeth. 5.Reduce the stresses transferred to the ridge by its resilience. 6.They are tough. 7.Good esthetics. Disadvantages: 1.Law abrasion resistance. 2.May stain during use.

1.Abrade the opposing natural and artificial teeth. 2.Porcelain denture teeth Advantages: 1.Hard. 2.have high wear resistance. 3.Natural appearance. Disadvantages: 1.Abrade the opposing natural and artificial teeth. 2.clicking sound against porcelain. 3.More susceptible to fracture(brittle). 4.Mechanical bond is required to denture base resins. 5.Polishing of ground surfaces is difficult.

1.May exhibit flat appearance, lacking of depth. 3.Facings when anterior teeth is to be replaced metal packing with porcelain or resin facing may be used. It is usually used with metallic denture bases.  Advantages: 1.Metal packing increase strength. 2.Can be used when there is insufficient interocclusal space to use resin denture teeth. Disadvantages: 1.May exhibit flat appearance, lacking of depth. 2.Metal backing may affect shade. 3.Difficulty in fabrication of metal backing due to occlusion and articulation.

1.It requires enough space mesiodistally and occlusogingivally. 4.Tube teeth: It is an acrylic or porcelain teeth in the form of a tube have a channel in its base to fit a post on the metal framework. Advantages: 1.Used as a single anterior or posterior tooth replacement, where space is available , with good esthetics. 2.No need for flasking and processing the denture teeth. The tube teeth are cemented to the metal posts. Disadvantages: 1.It requires enough space mesiodistally and occlusogingivally. 2.It is used with metallic denture base, which cannot be relined.

1.May be unaesthetic; acrylic or composite veneer will improve it. Materials used in construction of artificial teeth 5.Metal teeth   Advantages: 1.Can be used where space is limited for posterior teeth replacement. 2.Increased resistance to fracture and abrasion. Disadvantages: 1.May be unaesthetic; acrylic or composite veneer will improve it. 2.Difficult to adjust occlusion

Damage of the occluding surfaces. Wear of artificial teeth Consequences of wear Damage of the occluding surfaces. Loss of vertical dimension of occlusion. Alteration of the functional path of masticatory movement. Loss of masticaory efficiency. Fatigue of masticatory muscle.