OB A3- Ageing

Question 1

Describe the changes in enamel.

Answer 1

>Non-vital tissue – no active changes
>Surface changes:
– attrition - incisal / occlusal
– approximal wear – arch shortens
>Acquired lamellae
>Post-eruptive maturation
>Ionic exchange – e.g. Fluoride
– exchange of F- with OH- in lattice
– more perfect structure
– more resistant to acid demineralisation

Question 2

what is more affected by ageing than enamel?

Answer 2

Pulpo-dential complex :
>A vital tissue
> age changes more evident
> also response to environmental stimuli

Question 3

How does age affect the “dentinal” part of the complex?

Answer 3

• Secondary dentine (formed after root completion)

- Sclerosis in the root (starts at apex and moves up)

Question 4

How does age affect the “pulpol” part of the complex?

Answer 4

> Decreased pulp volume
Decreased cells by 50%:
-decreased undifferentiated cell which means decreased potential for the pulp to respond)
-odontoblasts: by 70 years 50% have gone via apoptosis, small-cubdoial with age and less synthetic organelles
-less activity by fibroblasts
decreased vascular
Decreased nerves and decreased sensitivity

Question 5

Describe true pulp stones caused by calcification.

Answer 5

tubular structure from odontoblast like cells

Question 6

Describe false pulp stones caused by calcification

Answer 6

calcified fibrous tissue

Question 7

what are the age changes of cementum?

Answer 7

• Thickness increases by up to 3x between ages 16-70
• can obstruct / constrict the apical foramen
• Helps compensates for wear

Question 8

what are age changes of bone ?

Answer 8

• Less dense
• Cortical bone mass falls between 25 and 75 years
  > By 10% in males
  > By 40% in females
• More brittle
• Less vascular
• Some osteoporosis may be evident
• Slower wound healing

Question 9

how does alveolar bone change with age?

Answer 9

• Bone remodels with age

- Made worse by: tooth loss, periodontal disease

Question 10

How are problems with alveolar bone minimised`?

Answer 10

– Prevent tooth loss
– Good dentures
– Implant or overdenture supported

Question 11

what are the age changes with the nervous system?

Answer 11

> Decrease in nerve cell numbers:
– 36-60% cerebral cortex
– 5-50% spinal cord
Peripheral nerve function decrease – e.g. conduction velocity decreases
Impaired synaptic function > Decreased taste acuity

Question 12

what are the age changes with muscle?

Answer 12

>30% decrease in muscle mass :
– Accelerated between 70+80 years 
– Decrease number of motor units
> Decrease in muscle strength
> Masticatory muscles :
– 40% decrease in cross sectional area from 20 and 90yrs
– Increase fat content 
– Decreased bite forces 
– Decreased precision

Question 13

what are the age changes with the peridontium?

Answer 13

-Vascular changes :
>thickening of vessels walls
>narrowing of lumen
-loss of cellularity 
-increasing fibrosis 
-PDL fibre bundles thicker