10 - Periodontal consideration in restorative: occlusion Flashcards
What is the function of the periodontium?
- attach teeth to jaws
- dissipate occlusal forces
What are the natural forces experienced by the periodontium?
- vertical forces
- tension (PDLs)
- compression (apical area)
- viscous forces (fluid within the area allows for gel-like dissipation)
What are the unnatural forces experienced by the periodontium?
- horizontal forces
- constant (orthodontic)
- intermittent (jiggling in occlusion)
Define excessive occlusal force.
Occlusal force that exceeds the reparative capacity of the periodontal attachment apparatus which results in occlusal trauma or cause tooth wear
Define occlusal trauma.
Injury resulting in tissue changes within attachment apparatus including the PDL, alveolar bone and cementum, as a result of occlusal forces
How does the width of the PDL affect mobility?
Wider = more mobile
How does the height of the PDL affect mobility?
Shorter = more mobile
Describe the difference between an intact periodontium and reduced periodontium experiencing excessive occlusal forces.
- 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
How does inflammation impact mobility?
- 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
When is tooth mobility not pathological?
- 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)
When should there be intervention with mobile teeth?
- progressively increasing
- symptomatic
- interferes with restoration of teeth
What can be done to reduce mobility?
- control of plaque
- correction of occlusal relationships (ie high restorations)
- splinting
Define primary occlusal trauma.
Injury resulting in tissue changes from excessive occlusal forces applied to teeth with normal periodontal support
Describe the response of a healthy periodontium to primary occlusal trauma.
- 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)
Define secondary occlusal trauma.
Injury resulting from normal or excessive occlusal forces applied to teeth with reduced periodontal support
Describe the radiographic presentation of occlusal trauma.
Funnel shaped bone defect around roots
Define fremitus.
Palpable or visible movement of tooth when subjected to occlusal forces (ie bounce on early contact)
How do you diagnose occlusal trauma?
- progressive tooth mobility
- fremitus
- occlusal discrepancies
- wear facets
- tooth migration
- root resorption
- sensitivity
- radiographic
Describe the effect of excessive occlusal loads on a periodontally involved dentition.
- inflammation from both forces and plaque
- zone of co-destruction increases rate of progression of bone loss
How do you manage tooth migration?
- treat perio
- correct occlusal relationships
- accept position and stabilise
- move teeth orthodontically and stabilise
How does occlusal trauma impact periodontal therapy?
- 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
How do you correct occlusal relationships?
- selective grinding
- restorations
- orthodontics
When is splinting appropriate?
- mobility due to advanced LOA
- mobility is causing discomfort and difficulty chewing
- teeth require stabilisation for debridement
How do excessive occlusal forces impact the gingiva?
No correlation
