Composition Of Teeth Flashcards
Enamel
Forms the outer surface of the crown of the tooth
The most densely mineralised and hardest substance in the body
It’s chemical composition is 96% inorganic and 4% organic plus water giving it the ability to resist wear
No nerve supply and does not respond to stimuli
Thickest at the incisal and occlusal area but becomes thinner at the cervical margin
Dentine
Forms most of the structure of the tooth
Tough, slightly elastic and yellow
Capable of responding to stimuli unlike enamel
It can repair itself by laying down a secondary layer
Cementum
The covering of the root of the tooth
Pale, yellow calcified tissue
Resembles bone in composition and is the lease mineralised of the dental hard tissues
Not normally visible in the mouth
Main function is to give attachment to the supporting fibres which attach the teeth to the bone
Pulp
Enclosed in the dentine
Made up of soft tissue which contains nerve fibres and blood and lymph vessels which enter the tooth through the apical foramen
The pulp in the crown of the tooth is contained within the pulp chamber and in the root of the tooth within the root canals
Gingivae
Tough fibrous layer of connective tissue covering the bone
Contains blood vessels that supply the bone with nourishment
Around the necks of the teeth the epithelium and outer layer of this tissue are attached tightly, preventing debris passing down the side of the tooth and down to the periodontal membrane and bony socket
Teeth are shaped and arranged In each arch so food is deflected away from this tissue to prevent from injury
Incisors
Eight incisors in both the permanent and primary dentitions
Work together to form a cutting and shearing surface
They cut and incise food into small pieces
These teeth are also important in speech and appearance
Canines
Four canine teeth in both dentitions
Last of the anterior teeth
Function is to grip, hold and tear food
Great importance in maintaining facial aesthetics ‘corner stones’. The alveolar bone produces an eminence over the canines root, therefore loss will lead to the face assuming a shrunken appearance
Premolars
Only in permanent dentition and there are 8, replace the primary molars
Dual function of assisting the canines by tearing food and it grinding food in a similar way to the molars
2 cusps, one buccally and the other palatally / lingually
Molars
Present in both dentitions
Primary dentition there are 8 and in the permanent there can be up to 12
Large occlusal surfaces with which they can grind and crush food
Last permanent molar is often missing, underdeveloped or unerupted. May be as a result of our evolutionary change in the size of our jaws
