Week 6 Sharma- Interdisciplinary Periodontics Flashcards
What is rationale for performing periodontal therapy first?
- Stable gingival margins before tooth prep
- Adequate tooth length
- Perio tx after ortho tooth movement and restos may change tooth position
- Successful aesthetic and implant procedures need specialised perio procedures
- Non inflamed, healthy tissues are less likely to change (shrink) as a result of subgingival resto tx
What is role of periodontist in preprosthetic surgery?
- Management of mucogingival problems
- Preservation of ridge morphology after tooth exo
- Crown lengthening procedures
- Alveolar ridge reconstruction
How can we preserve ridge morphology following exo?
Bone graft placed in socket after exo rather than compressing socket
Do bone graft stay in place forever?
No, act as template or scaffold for new bone formation. Hold the space.
What is SCAT?
Supracrestal attached tissues = junctional epithelial + supracrestal tissue (2.04mm)
Used to be called biologic width
What is issue with subgingival vs supragingival resto margins?
- Supra: unaesthetic in anteriors
- Sub: can affect gingival tissues (SCAT)
How to evaluate SCAT?
- MOST ACCURATE: bone sounding
- Radiographic interpretation can suggest IP violations of SCAT
- Pt discomfort when resto margin is assessed with perio probe indicated SCAT violation
- Histological evaluaiton is definitive but not clinically possible
What is bone sounding? What measurement indicated SCAT violation?
- Measure distance between bone and resto margin using a sterile perio probe under LA
- Probe is pushed through attachment tissues from sulcus to underlying bone
- Can be done on healthy gingiva tissue on B/L bone or IP bone surfaces.
- <2mm at one or more locations = SCAT violation
How to manage SCAT violation?
- Surgically removing bone away from proximity to the restoration margin (faster outcome)
- Orthodontically extruding the tooth and thus moving the restorative margin away from the bone.
What is the rule for clinical margin placement?
- Sulcus ≤1.5mm, restoration margin no more than 0.5mm below the gingival tissue crest.
- Sulcus >1.5mm, margin at half the depth of the sulcus below the tissue crest.
- Sulcus >2mm, gingivectomy to lengthen the teeth and create a 1.5mm sulcus. Then use Rule 1.
What is crown lengthening?
The surgical procedure to expose adequate clinical crown to prevent placement of the crown margin into the area of biologic width.
What is the aim of crown lengthening?
At least 3 mm between the most apical extension of the restorative margin and alveolar bone.
What are indications for surgical crown lengthening?
- Subgingival caries or fracture
- Inadequate clinical crown length for retention
- Unequal or unaesthetic gingival heights
How to do crown lengthening when there is >3mm soft tissue vs <3mm soft tissue?
- >3mm: soft tissue crown lengthening (remove soft tissue)
- <3mm: crown lengthening with osseous reduction
What are contraindications of surgical crown lengthening?
- Surgery would create unaesthetic outcome
- Deep caries or fracture would require excessive bone removal on contiguous teeth
- Poor prognosis in restorative context
How can ortho extrusion be done?
- Slow force (months)
- Rapid force (weeks)
What is rapid force ortho extrusion?
- Weeks
- Tooth movement only
- Supracrestal fibrotomoy- releasing fibres with scalpel every few weeks as force is being applied
What is slow force ortho extrusion?
- Months
- Bone and teeth move
- Need surgical correction after tx to remove excess bone
When is ortho extrusion indicated?
SCAT violation is on the interproximal side, or if the violation is across the facial surface with ideal gingival tissue level.
When is alveolar ridge reconstruction done?
Prior to fixed prosthesis or implant therapy in the form of soft or hard tissue augmentation.
How is papillary height established?
Contact area
- Level of bone
- Biological width
- Form of gingival embrasure
How much interdental papilla will there be based on interproximal tooth contact to bone distance?
- ≤ 5mm (bone to contact area) → papilla always fill the space
- 6mm → 56% of the papillae fill the space
- 7mm → 37% of the papillae fill the spaces
How does embrasure of contact point impact papilla shape?
- Embrasure too wide, papilla flattens out, assumes a blunted shape.
- Embrasure ideal width, papilla assumes a pointed form, normal sulcus
- Embrasure too narrow, papilla grows out to the facial and lingual, and become inflamed.
Options to manage black triangles?
- Tissue-colored (pink) ceramics to make porcelain papillae directly on the restoration.
- Carry the interproximal contacts apically toward the papilla with fillings
Remember- excessively long interproximal contacts creates rectangular, somewhat unaesthetic, tooth forms.
