Periodontal considerations in restorative dentistry 1 Flashcards
aims of periodontal therapy
- To arrest the disease process
- Ideally, to regenerate lost tissue
- To maintain periodontal health long term
RESULT = prevention of tooth loss
periodontal therapy as aid to restorative dentistry
- Improves soft tissue management
- Establishes stable gingival margin position
- Contributes to aesthetics
- Reduces tooth mobility
- Informs prognosis
issues with inflammed gingival margins
- Bleeds during operative procedures
- Is unstable in its apico-coronal location
- Makes effective restorative dentistry impossible
Gingival recession following non-surgical periodontal therapy
- Black triangles
- papilla loss
issue here
Gingival inflammation and papilla loss associated with a poorly fitting veneer and excess luting cement
- Rolled inflamed gingivitis
2 weeks after removal of veneer and debridement there has been further gingival recession
- Stable now
affect on gingval margin of effective non-surgical and surgical Tx on periodontitis
recession
gingival margin position and restoration placement
crucial
needs to be stable
stable gingival margin when
it is healthy
In general the gingival margin should be monitored for at least 3-6 months AFTER completion of periodontal treatment to check that it is stable.
- Once stability confirmed – THEN place restorations
need to wait, try to manage pt
4 prosthodontic options for partially dentate
- FPD with natural abutments (bridges)
- RPD with natural abutments
- Implant supported prosthesis
- Combinations of the above
potential damages from crowns and bridges
- Plaque retention
- Location and fit of restoration margins
- Contour of retainers and pontics
- Unfavourable transmission of occlusal forces
- Pulp damage
potential damages for RPDs
- Plaque retention
- Gingival margin coverage
- Direct trauma from components
- Unfavourable transmission of forces (occlusal, insertion and removal etc)
fixed vs removable prosthetics?
From a periodontal perspective fixed prostheses are usually preferable
assume done well
issue here
Poor fit
Cover gingival margin
Even with excellent plaque control – hard/impossible to keep clean
so Gingival inflammation of palate – damage to adj tissues
good RPD design for periodontal health
- Effective tooth support
- Clearance of gingival margins
- Rigid connectors
- CoCr alternative*
- Relief around gingival margins – wont accumulate plaque
- Acrylic can work too – esp with clasps – clear gingival margin aim*
restoration margins
never perfect
all will attract plaque
poorer ones = attract more
issue here
Persistent inflammation associated with poorly fitting subgingival crown margins
- accumulated plaque, cannot clean as subgingival
inflammation around laterals and centrals
supracrestal attachment
tissues are histologically composed of the junctional epithelium and supracrestal connective tissue attachment.
- The term biologic width should be replaced by supracrestal tissue attachment (Since 2017 classification)
average of 2mm – vary between people and sites in mouth
- above crest of alveolar bone
- some extend above ACJ, junctional epithelium can vary (attached to cementum and dentine sometimes extend to enamel)
don’t want to infringe on supracrestal attachment when placing margins
interproximal area consideration
supracrestal attachment extends coronally
flows around contour of tooh
where should restoration margins sit
supeiror to supracrestal attachment
4 possible outcomes of restoration margins encroaching on supracrestal attachment
- Persistent inflammation
- Loss of attachment
- Pocketing
- Recession
issue here
lost supracrustal attachment of papilla as crown margin kept at one level all the way round tooth not respected interdental papilla
supracrestal attachment
bone
crown margin
positioning?
The supracrestal tissue attachment can be accommodated between the crown margin and the bone. - want at least 2-3mm between crown margin and bone
- If the inflammation can be resolved the crown margins will become accessible.
importance of well fitting provisional restorations
Indication of how good crown prep is
- If doesn’t look right then final restoration won’t be
is it?
- thin in places
- margins not in right place
- interdental brushing – specify to lab, send with casts
- too apical –> will lose interdental papilla
Healthy Tissue + Carefully located preparation margins =
Easy impression + Reduced risk of disease
Follow height of gingival margin contour
issue here
Restoration margins encroaching on supracrestal tissue attachment
Too subgingival margins
how to resolve prepared margins that are too subgingival
surgical crown lengthening
Not enough space between restoration margin and alveolar bone -> Inflammation
Flap raised as need to lower bone as cannot alter prep to be more coronal as already done - to get 3mm
- supracrestal margin and gingival margin can reform so no more on going inflammation due to restoration margin
Not reliable can get rebound and recession
treatment here
Through bone removal and manipulation of the
muco-periosteal flap the supracrestal tissue attachment has been relocated apically, allowing access to the crown
margins and facilitating a return to tissue health.
- Will likely need to replace crowns – wait 6 months so stable
overhanging restoration issues
- associated with more inflammation and bone loss
- than non-restored sites (Gilmore 1971)
- larger the overhang - greater the bone loss (Jeffcoat et al 1981)
- development of pathogenic flora (Lang 1983
USE A WEDGE
contour of restoration
should be same as tooth
hard for pt to clean if incorrect
don’t try to compensate for gaps/black triangles with long contact points
- hard to clean -> periodontitis – inflammation, swelling of tissues, poorly contoured prep (bulbous crowns)
result of incorrect tooth prep
crowns will be wrong shape (bulbous, look bad)
technicians have no choice but to work with what you give
prognosis Q in periodontitis pts
Will more teeth be lost in the near future?
Chart down the individual prognosis of each tooth
- Resorted, carious, periapical pathology, bone level, mobile
- Overeruption and drifting of anterior teeth*
- Periodontitis stable*
- Hard but able to restore*
soft tissue harmony concerned about
- Gingival health
- Gingival display
- General gingival inclination
- Gingival outline and symmetry
Optimal gingival aesthetics – can assess and analyse pt complaint
approximation of line of zeniths
canine to canine
touching central incisors
lateral incisors generally 1-2mm below
parallel to incisal edges of centrals
pt here has
gummy smile
- appears to have small, square teeth
- More gingiva on pt right than left
- Teeth slightly shorter on right than left
Pockets 3mm or less – so not deep – no inflammation
Supracrestal attachment sits coronally
Can sound for bone – callipers
- Reasonable long way away 5mm
Can have gingival margin moved up as still have 3mm between gingival margin and bone
- More tooth show, less gingiva show in smile
gingival hypertrophy
drug induced (ca channel blockers)
makes restorative dentistry impossible until tx
gingiva grown over where crowns are
- Try to improve plaque control – but impossible for pt to maintain due to overgrowth – impossible to clean
Remove tissue – scalpels and lasers
Allow to heal
- Able to restore but not ideal after week or two
- Year later – rebound overgrowth of gingiva – common in drug induced
- If doesn’t bother pt and under control – keep under review
issue here
lack of clinical crown heigh so retention of resotration impossible
check Radiographs
- no bone loss and reasonable root length
Consider – to lengthen crowns to restore them and to maintain supracrestal attachment width will need to remove bone
crown lengthening surgery
if clinical crown height too small for retention of restoration
radiograph - assess bone level and root status
Diagnostic wax up of what aim to achieve
- Cut the cast to level want to cut gingiva to after placing wax restorations
- generate stent, place onto pt mouth in surgery so know where to cut to (at least 3mm of space between gingival margin and bone)
After crown lengthing surgery – revealed some tooth structure that can utilise for provisional restorations
camouflage gingival recession
recession defects
Black triangles – no way to surgically correct (no way to replace missing papilla)– think around
- Acrylic gingival veneer
- Pink acrylic
- Plaque trap – so minimise wearing – only when going out and will be self concious
possible tx for uneven tooth width, margins and contact points
restorations can camouflage recession
Reshaping of teeth to redistribute size/width, placement of margin, contact points
- Can end up with long teeth
- These restorations are mainly supra gingival – barely into gingival sulcus
- low – medium smile line helps
- Contact point left shorter for ease of cleaning
use of Stents and casts
Compromise – canine still prominent but gingival margin more even
