Periodontal considerations in restorative dentistry 2 Flashcards
periodontium is
PDL, cementum, alveolar bone
function of PDL
- To attach the teeth to the jaws
- To dissipate occlusal forces
- Viscoelastic capacity
- Communicate with brain to control load applied
general forces on tooth
down long axis
- Tension
- Compression
- Viscous forces
(normal)
constant horizontal forces
from orthodontics
sources of intermittent horizontal forces
Occlusal (Jiggling), parafunctional habits, abnormal tooth contacts, arm of clasp on denture
issue with horizontal forces on tooth
not physiolgical
negative effect
remodelling of bone
what movement can cause bone remodelling
Tipping movements due to PDL being alive and communicating with bone
Application of forces
- leads to pressure and tension
- pressure – resorb
- tension – elongation of ligaments deposition of bone
Remodelling effect = tooth tipped
effect of abnormal occlusal forces on periodontium depends on
- The healthy periodontium
- The healthy but reduced periodontium
- Had periodontitis in past
- The diseased periodontium
- (the presence of plaque-induced)
- Coexisting plaque present
excessive occlusal force
- occlusal force that exceeds the reparative capacity of the periodontal attachment apparatus, which results in occlusal trauma and/or causes excessive tooth wear (loss).
- Under occlusal force all the time but body able to dissipate
- Too much – excessive – body cannot deal with
- Under occlusal force all the time but body able to dissipate
occlusal trauma
term used to describe injury resulting in tissue changes within the attachment apparatus, including periodontal ligament, supporting alveolar bone and cementum, as a result of occlusal force(s).
- may occur in an intact periodontium or in a reduced periodontium caused by periodontal disease.
are teeth ever not mobile?
- Teeth are alread mobile – not fused to bone, unless in pathological circumstances*
- Always have a small degree of mobility*
- can increase - issue*
4 factors affecting tooth mobility
- width of PDL
- height if PDL
- inflammation
- number, shape and length of roots
how does width of PDL impact tooth movement
has it been increased or decreased?
how does the height of PDL impact tooth movement?
length of level of crown (80% way down tooth = greater movement than just 30%)
Normal height PDL move less in horizontal direction than reduced height periodontium (right) with same force applied
how does inflammation impact tooth movement
- tight, pink, fibrous healthy forms a collar holding tooth in place
- Swollen, oedematous, filled with inflammatory fluid and cells rather than fibrin? And collagen? = move
how does number, shape and size of roots impact tooth movement
- Small, singular short root move less than multi-rooted large roots
tissue tone/inflammaiton impact on periodontium
Increased tissue tone
Left – calculus, pocket developed, no attachment, deep rete ridges, inflammatory cells and exudate and swelling – no connection
Right – healthy, long junctional epithelium, tight fibrous cup around tooth, reduced movement
Resolution in inflammation and improvement of tissue tone = reduction in mobility (simple non-surgical perio therapy)
when can tooth mobility not indicate pathology
if
- Absence of inflammation or any other signs of disease
- Stable
if tooth mobile but not pathological then may
- indicate successful adaptation of the periodontium to functional demands (as a result of parafunction – give more space to move to dissipate the load, higher load – more space to dissipate the load)
and/or
- reflect the nature of the remaining attachment (had perio in the past so lost attachment but now under control)
tooth mobility can be accepted unless (3)
- It is progressively increasing
- It gives rise to symptoms (discomfort)
- It creates difficulty with restorative treatment
3 therapies to reduce tooth mobility
- Control of plaque-induced inflammation (FIRST)
- Correction of occlusal relations
- Abnormal occlusal relations causing excessive occlusal load, damage to periodontium, can be due to parafunction
- Splinting
- To healthy, stable teeth to get mutual support
primary occlusal trauma
Injury resulting in tissue changes from excessive occlusal forces applied to a tooth or teeth with normal periodontal support
- It occurs in the presence of normal clinical attachment levels, normal bone levels, and excessive occlusal force(s).
- Tooth itself has no periodontal disease – but is subject to occlusal trauma
response of healthy periodontium to large but managemable occlusal load
PDL width increases until forces can be adequately dissipated, then the PDL width should then stabilise
- Tooth mobility will be increased as a result
- This can be regarded as successful adaptation to increased demand and therefore physiological
If demand is subsequently reduced, PDL width should return to normal
- Identify the cause – crown high, parafunction, overerupting, lateral excursion load – fix, PDL should return to normal and mobility reduce
response by PDL if excessive occlusal force
If the demand of occlusal forces is too great or the adaptive capacity of the PDL reduced, PDL width may continue to increase
- PDL width and tooth mobility fail to reach a stable phase
- This failure of adaptation may be regarded as pathological
- Don’t adapt – become more and more mobile = pathological problem
histological effect of excessive occlusal load
zones of tension and pressure within the adjacent periodontium.
- location and severity of the lesions vary based on the magnitude and direction of applied forces.
on the pressure side, these changes may include increased vascularization and permeability, hyalinization/necrosis of the periodontal ligament, hemorrhage, thrombosis,
- lead to bone resorption, and in some instances, root resorption and cemental tears.
on the side of tension, these changes may include elongation of the periodontal ligament fibres and apposition of alveolar bone and cementum.
result of sustained occlusal trauma
density of the alveolar bone decreases while the width of the periodontal ligament space increases,
- leads to increased tooth mobility
radiographic widening of the periodontal ligament space, either limited to the alveolar crest or through the entire width of the alveolar bone
secondary occlusal trauma
injury resulting in tissue changes from normal or excessive occlusal forces applied to a tooth or teeth with reduced periodontal support.
- It occurs in the presence of attachment loss, bone loss, and normal/excessive occlusal force(s).
effect of secondary occlusal trauma
Less well able to adapt to excessive forces
For a given amount of force = greater effect
Less bone = the more pressure = the more wobbly
what happens when PDL is healthy and there is secondary occlusal trauma placed on tooth
But when PDL healthy, no plaque induced gingivitis or inflammation (reduced but healthy PDL)
- secondary occlusal trauma will not lead to further LOA or increased probing depth (will get mobility)
occlusal trauma
criteria
- Tooth mobility which is progressively increasing
- and/or*
- Tooth mobility associated with symptoms
- with*
- Radiographic evidence of increased PDL width
identify occlusal trauma on radiograph
25 – see wedge shaped horizontal defect
Lower incisor – vertical bony defect, widening of PDL space (not normal) – due to excessive loads on tooth
occlusion and periodontitis
association with bony defects
NO association with vertical bone defects
- More of function on how much bone there is at beginning
- Thin = horizontal tend
- Thick = zone of bone loss for one tooth and tooth behind with peak inbetween – look like vertical (due to occlusal force – central area survived as far away from source)
due to width of initial bone before occlusal forces
manifestation of anatomy
vertical bone defects assoiciation between occlusion and perio
3 situations
Simply periodontitis – inflammation in pocket – causes zone of destruction of bone (circle)
- 2 teeth close – thin interdental bony septum destroyed by circle – horizontal bone loss look
- Intermediate bony septum – bony peak left
- thicker interdental bony septum – zone leaves reasonable amount left
due to width of initial bone before occlusal forces
manifestation of anatomy
splinting role
minimise mobility – make pt comfortable more than affecting periodontal outcome
3 cases splinting may be appropriate
- Mobility is due to advanced loss of attachment
- Mobility is causing discomfort or difficulty in chewing
- Teeth need to be stabilised for debridement.
issues with splinting
- Does not influence the rate of periodontal destruction.
- May create hygiene difficulties
Is a treatment of “last resort”
tooth migration due to
- Loss of periodontal attachment
- Unfavourable occlusal forces
- Unfavourable soft tissue profile (lip trap)
Teeth splay out as less bone to hold them in
tooth migration issue
Trauma, inflammation, baggy, oedematous weak tissue
tooth migration management options
- Treat the periodontitis - HPT
- Correct occlusal relations
Either:
- Accept the position of the teeth and stabilise or
- Move the teeth orthodontically and stabilise
