Age Changes in Enamel, Dentin and Pulp
Definition
Ageing is defined as a process of morphological and physiological disintegration as distinguished from infant, childhood and adolescence which are typified by processes of integration and coordination.
Major Tissues of the Tooth
AGE CHANGES IN ENAMEL
MACROSCOPIC
1. Becomes darker
2. Attrition, Abrasion, Erosion
3. Longitudinal cracks
MICROSCOPIC
1. Decreased
- Enamel rod ends
- Perikymata
- Permeability to fluids
2. Increase in nitrogen and fluorine
3. Increased resistance to decay
MACROSCOPIC CHANGES
1. COLOUR
- Becomes darker with age.
- Associated with changes in the organic portion of enamel, presumably near the surface.
ATTRITION- Physiologic wear of the occlusal surfaces and
proximal contact points as a result of mastication. Characterized by a loss of
vertical dimension of the crown and by flattening of the proximal contour.
Causes
- Masticatory stress
- Para-functional habits
Stage I- Enamel wear at cusps and incisal edges without
dentin exposure.
Stage II- Enamel wear and dentin exposure on incisal edges
and there is isolated area over the individual cusps.
Stage III- Wear of enamel forming a broad strip on incisal
edges and therefore the confluence of two are more areas of wear and tear over
adjacent cusps.
Stage IV- Wear of enamel and dentin on incisors to make a
plateau on the teeth to make a central area of dentin surrounded by a
peripheral rim of enamel.
ABRASION- Pathological wearing away of tooth through
abnormal mechanical processes.
Examples-
- Abrasive dentifrice
- Occupational
- Improper flossing
EROSION- Loss of tooth substance by a chemical change that
doesn't involve known bacterial action.
-Lingual erosion Example-
- Chronic vomiting
- Acidic carbonated beverages
-Labial erosion
3. LONGITUDINAL CRACKS
- May be developmental in origin.
- Although their numbers don't increase with age , they become more obvious.
Site-specific thickness of enamel
- Thinning of enamel at the extent of cementoenamel junction.
- Thickening at the incisal edge (maximum facial-palatal width) due to wear with advancing age.
- This results in an overall reduction in the height of the tooth crown.
MICROSCOPIC CHANGES
- Transverse wave like grooves which lie parallel to every other and also to cemento -enamel junction.
- There is completely covering of the surfaces of unerupted and recently erupted teeth with pronounced rod ends and perikymata.
- In Advanced age, there are slower flattening of perikymata and generalized loss of rod ends which will eventually lost.
- More rapid loss of structure occurs on Facial and lingual surfaces of Anterior teeth
