10 - Periodontal consideration in restorative: occlusion

Question 1

What is the function of the periodontium?

Answer 1

• attach teeth to jaws
• dissipate occlusal forces

Question 2

What are the natural forces experienced by the periodontium?

Answer 2

• vertical forces
• tension (PDLs)
• compression (apical area)
• viscous forces (fluid within the area allows for gel-like dissipation)

Question 3

What are the unnatural forces experienced by the periodontium?

Answer 3

• horizontal forces
• constant (orthodontic)
• intermittent (jiggling in occlusion)

Question 4

Define excessive occlusal force.

Answer 4

Occlusal force that exceeds the reparative capacity of the periodontal attachment apparatus which results in occlusal trauma or cause tooth wear

Question 5

Define occlusal trauma.

Answer 5

Injury resulting in tissue changes within attachment apparatus including the PDL, alveolar bone and cementum, as a result of occlusal forces

Question 6

How does the width of the PDL affect mobility?

Answer 6

Wider = more mobile

Question 7

How does the height of the PDL affect mobility?

Answer 7

Shorter = more mobile

Question 8

Describe the difference between an intact periodontium and reduced periodontium experiencing excessive occlusal forces.

Answer 8

• intact periodontium experiences less movement due to the fulcrum being higher up the root
• the magnitude of movement (same amount of force but more movement) is greater in a reduced periodontium due to the fulcrum being more apical

Question 9

How does inflammation impact mobility?

Answer 9

• inflammation causes decreased tissue tone
• decreased tissue tone due to breakdown of tissue to fight bacteria
• if inflammation is resolved, tissue replaces collagen and is vascularised and can support tooth better

Question 10

When is tooth mobility not pathological?

Answer 10

• successful adaptation to increased functional demands
• bruxists may have excessive load
• if there is a tooth that experiences excessive force, PDL may widen to allow tooth to be taken out of occlusion (mobility halts here)

Question 11

When should there be intervention with mobile teeth?

Answer 11

• progressively increasing
• symptomatic
• interferes with restoration of teeth

Question 12

What can be done to reduce mobility?

Answer 12

• control of plaque
• correction of occlusal relationships (ie high restorations)
• splinting

Question 13

Define primary occlusal trauma.

Answer 13

Injury resulting in tissue changes from excessive occlusal forces applied to teeth with normal periodontal support

Question 14

Describe the response of a healthy periodontium to primary occlusal trauma.

Answer 14

• PDL width increases so that forces are adequately dissipated
• mobility is increased
• regarded a successful adaptation to increased demand
• if demand is reduced, PDL will return to normal
• if forces are EXCESSIVE, PDL will continue to widen and become unstable (considered pathological)

Question 15

Define secondary occlusal trauma.

Answer 15

Injury resulting from normal or excessive occlusal forces applied to teeth with reduced periodontal support

Question 16

Describe the radiographic presentation of occlusal trauma.

Answer 16

Funnel shaped bone defect around roots

Question 17

Define fremitus.

Answer 17

Palpable or visible movement of tooth when subjected to occlusal forces (ie bounce on early contact)

Question 18

How do you diagnose occlusal trauma?

Answer 18

• progressive tooth mobility
• fremitus
• occlusal discrepancies
• wear facets
• tooth migration
• root resorption
• sensitivity
• radiographic

Question 19

Describe the effect of excessive occlusal loads on a periodontally involved dentition.

Answer 19

• inflammation from both forces and plaque
• zone of co-destruction increases rate of progression of bone loss

Question 20

How do you manage tooth migration?

Answer 20

• treat perio
• correct occlusal relationships
• accept position and stabilise
• move teeth orthodontically and stabilise

Question 21

How does occlusal trauma impact periodontal therapy?

Answer 21

• decrease in clinical attachment gain after HPT
• increased CAL over time
• mobile teeth do not respond as well as stable teeth
• occlusal therapy is associated with clinical attachment gain

Question 22

How do you correct occlusal relationships?

Answer 22

• selective grinding
• restorations
• orthodontics

Question 23

When is splinting appropriate?

Answer 23

• mobility due to advanced LOA
• mobility is causing discomfort and difficulty chewing
• teeth require stabilisation for debridement

Question 24

How do excessive occlusal forces impact the gingiva?

Answer 24

No correlation