Implant symposium Flashcards
What are the 3 things you need to know about when a patient arrives about their implants?
- Implant name/make
- Implant diameter/width
- Connection type
what is the cover screw?
Small component that fits on top of fissure head into connection and is flush with the level of the implant. Used in a 2-stage implant procedure to allow osseointegration.
What is the healing abutment?
Essentially a tall cover screw, it sticks through the gum and allows access to the implant in order to do impressions. They come in different heights and widths and selection is dependent on tissue thickness and emergence desired.
What is the torque wrench?
Ensure that screws are tightened to the correct torque. Over-torquing can lead to screw fractures and under-torquing can cause prostheses loosening. Most screws need to be torqued between 15 and 60NCm.
What is impression copings?
Designed to record the position of an implant in an impression. They are screwed into/fit onto an implant before and imp. and are often colour coded to reduce errors.
What are implant abutments?
Components that are sometimes required to connect an implant to the final crown or bridge. They’re made of Ti or high strength ceramics. They’re often used when the angulation of an implant is unfavourable or when implants are divergent. They can be prefabricated, or CAD/CAM for specific prostheses.
Describe the closed tray technique
1) Healing abutment removed.
2) Impression coping screwed onto implant.
3) Light-bodied Si placed around impression coping.
4) Load impression tray with heavier-bodied (medium) Si.
5) Take impression.
6) Impression coping is then removed and placed by hand into the impression.
7) A Ti or stainless-steel implant replica is connected to the impression coping.
8) The technician will then cast the model with a special Si around the impression coping and replica to mimic the gingivae on the model.
Describe the open tray technique
1) Impression copings are screwed onto the implant.
2) A special tray with small holes in the region on the impression coping is tried in – should see coping poking through special tray.
3) Light bodied Si is placed around impression coping.
4) Load impression special tray with medium-bodied Si.
5) Take imp. and let set, the coping is then removed from the impression while the tray is still in the mouth – better accuracy of coping position.
What is the screw retained crown and its benefit?
Crown has a small hole in it – allows for it to be screwed into place.
Once positioned, the screw hole has a small piece of cotton wool placed and then composite.
Benefit = can be removed easily when required.
What is the screw retained bridge?
Have more than 1 implant crown connected by a pontic.
Works in a similar way to a crown – hole in crown implants to allow screwing.
What is the cement retained crown?
Sometimes a screw retained option isn’t available due to angulation of implant e.g. for U1s implant may be too far buccally.
An abutment is placed – a CAD/CAM personalised abutment may need to be created.
A crown can then be cemented on top of the abutment.
What is the cement retained implant bridge?
Not generally done nowadays due to retrievability issues i.e. is hard to remove to get access to implant.
Abutments are placed on implants and bridge cemented on top.
What happens with complex cases - pts with lots of missing teeth?
Once models have been cast, the lab can make a verification jig on the model.
This jig is tried in the pts. mouth to ensure model is accurate.
The acrylic jig is then converted into a Ti framework and teeth are then place on that.
What can go wrong with implants?
Sublingual haematoma – lingual bony plate perforated due to trying to place implant in lower anterior region, this can be a life threatening
Implant dislodged into sinus – possible for implant to then make way into ethmoidal air cells which can lead to infections, cavernous sinus thrombosis etc.
What is the criteria for successful implants?
Clinical immobility.
No evidence of peri-implant radiolucency.
Vertical bone loss of < 0.2mm annually after first year of service.
Lack of persistent/irreversible symptoms.
Which is the most successful implant?
single cemented crowns
What is the top-down approach?
Technical complications = prosthesis and abutment.
Biological complications = peri-implant tissues (soft and hard tissues).
What are the technical complications for removable prostheses and what do we assess?
Need to assess extensions, stability, and occlusal wear.
Check inside mouth for retention – abutment (may have worn down) and locator insert.
If the locator insert is worn down continually, ask pt. what they’re cleaning it in as this may be the cause.
What are the technical complications for fixed prostheses and which one is it the moss common with?
more common in screw retained restorations.
Decementation – may just need to recement loose bridge/crown.
Composite placed in the screw holes may be lost.
Loosening of the abutment or prosthetic screws.
Wear – tends to be greater in implants as don’t move around.
Chipping of porcelain.
What is biological complications most likely to affect and why?
More likely to affect cement-retained restorations more due to difficulty of clearing excess cement leading to a foreign body response.
What is peri-implant mucositis and what are the signs?
Reversible inflammatory reaction in the soft tissues surrounding an implant; very common. A plaque induced condition.
Bleeding and/or suppuration on gentle probing
No bone loss beyond crestal- bone level changes resulting from initial bone remodelling
What is peri-implantitis and what are the signs?
inflammatory reaction in the tissues surrounding an implant with loss of supporting bone. A plaque induced condition.
Bleeding and/or suppuration on gentle probing
Increased probing depth compared to previous examinations
Bone loss beyond crestal bone-level changes resulting from initial bone remodelling
What are we looking for visually with peri implant tissues?
Visual exam – colour, consistency (swelling, hypertrophic), sinus, recession.
What probing techniques do you use for peri-implant tissues?
Plastic probe used as metal probes may scratch Ti abutment creating a PRF; however, use a metal one if you don’t have access to a plastic one as much better to probe than not at all.
Use less probing force – 15g (as opposed to 25g).
Record at 6 points around implant.
Need to assess BoP, PPD, suppuration -> DON’T do BPE around implants (would not be representative).
What is implant mobility indicative of?
Implant mobility indicates failure of the implant due to loss of osseointegration – can occasionally occur with indistinct radiographic bone changes.
How often do we take radiographs assessing peri-implant tissues?
Important to take radiographs (PAs) to assess peri-implant bone levels – 2 yearly intervals OR if PPD changes and there’s signs of peri-mucositis.
What do we need to know about periodontal history?
Rate of implant failure/complications higher in pts. with history of treated perio. Disease.
Related to severity of perio. Disease.
Increased with presence of residual pockets.
How is type of restoration affecting the chance of peri-implant disease?
Type of restoration can also increase chance of peri-implant disease – linked units (i.e. bridges) are harder to clean around; also contour of the crown can affect cleaning ability.
How do we treat peri-implant disease?
Treat early and aggressively – targeted OHI; non-surgical debridement 6/12 (or 3/13 if bleeding present); consider modifying prosthesis e.g. so it’s easier to clean.
If non-surgical measures not working, could progress to surgical debridement ± implantoplasty (changing implant surface) ± use of chemotherapeutic agents.
What OHI do we give with patient with implants?
Toothbrushing technique – need to remove plaque from gingival margins.
IP cleaning – floss/tape, superfloss, ID brushes -> N.B. can pass floss much higher vs. normal tooth.
Chemical agents – CHX m/w or Listerine m/w (not recommended for long-term use).
What non-surgical tx can we do and what do we use for peri-implant disease ?
Can be completed with normal scaling instruments.
However, plastic, carbon fibre reinforced plastic, or Ti coated instruments are less likely to scratch Ti abutment.
Plastic and carbon fibre instruments are very brittle though and often break.
Ti coated instruments are thought to be the best option.
Chemotherapeutic agents (minimal evidence to support use) – systemic antibiotics (only use if acute infection), topical/local antimicrobials, CHX irrigation/gel.
