Restoration of Implants Flashcards
What is meant by prosthetically driven planning?
Top down approach
- Begin with end in mind
- Put implant in position where restoration would not be compromised
What are the phases of the implant journey?
Implant planning
Placement
Healing- pink firm and healthy
Impressions
Abutment selection
Provisionalisation- how long?
Loading
Definitive restorations- once maturation has occurred
What are the types of implant retained prostheses?
Removable prosthesis (like dentures)
-> Stud, bar, magnet retained
Fixed prosthesis -single or multi unit or full arch
-> Screw retained, cement retained
How does the denture retained by implant bar work?
3 implants splinted together
-> Denture clips on top
How do ball retained prostheses work with implants?
Implants placed with ball on top, clips onto female part on denture
How does the LOCATOR system work?
- Silicone inserts on implant instead of denture clip over implants
- Grip strength varies depending on colour
What can be done to make zirconia bridge frameworks looks aesthetic?
Cover with porcelain
What is used for a provisional in implants, what are the purposes of provisionals in his case?
Lab make temporary abutment and crown (peak material)
Allows maturation, shaping and healing- healthier proportions
-> Helps prevent shine through
What are the 2 techniques when taking impressions for definitive restoration with an implant?
Open tray- hole present to allow impression coping to go through (screwed into implant)
Closed tray- no need for hole in tray as coping gets stuck in impression material
What are the steps in the open tray technique?
- Has coping- threaded post which screws into implant (can be done by hand/screw driver)
- Impression tray is filled with rigid accurate elastomeric material like impregum is used
- Only way coping can be removed is by unscrewing
- Impression sets- unscrew coping and remove impression tray/material
- Screw implant analogue onto impression coping- on pouring there is a direct transfer from where implant is in mouth onto cast
When is open tray technique preferred?
Good if space for fingers and screw drivers
-> anterior region
What are the benefits of open tray technique?
Color-coded components corresponds to prosthetic
connection
High precision impression
Clear-cut tactile response for accurate positioning
Guide screw can be tightened by hand or with the SCS screwdriver
Safer as screw retained
What are the steps in the closed tray technique?
- Use different impression coping (T shaped), pressed down onto implant, material flows around, it gets stuck and is removed with impression material
- 2 pieces- one part goes onto implant head, second part (red) pushed on top to secure
- Parts click into place- will not be removed by accident
- Impregum (polyether) used
- When in lab- they will attach implant analogue
- Put soft silicone mask to allow movement of gingivae
- Pour as standard for any crown/bridge impression
What are the benefits of closed tray technique?
Color-coded components corresponds to prosthetic
connection
No additional preparation of tray
High precision impression
Clear-cut tactile response for accurate positioning
Preferred if less space- posteriorly
Cheaper
What are abutments used for?
Cn be used to correct angle implant is coming out at if not perfectly straight
What are the different types of abutments?
Come in range of sizes, shapes, materials (Ti, Zirconia, gold etc), colours
Can be standard or custom (crown prep-like)
What is preferred screw or cement retained?
Screw
What are the ADV of screw retained implant restorations?
More retrievable
Can be positioned for ideal aesthetics
Good retention even with <4mm abutment height
Better tissue response
What are the DIS of screw retained implant restorations?
Must be passive- technique sensitive
Susceptible to porcelain fracture
Susceptible to screw fractures and loosening
Higher cost
Difficult access
Occlusal interferences possible
What are the ADV of cement retained implant restorations?
Cement space acts as shock absorber
Easier access
Easier to fabricate
Lower cost
Better occlusal control
What are the DIS of cement retained implant restorations?
More universal aesthetics- less custom
Unpredictable retrievability
> 5mm abutment height required for retention
Be careful not to get cement under soft tissue- risks periimplantitis
What are the aesthetic challenges with implants?
Patient will want teeth to look as similar as possible
Survival of implants is great but appearance may be lacking
What can lead to poor aesthetic in implants?
If implant is too deep/poor angulation and tissues are inflamed and not well keratinised or receded
If zenith too low
-> Long term provisional to remodel gingivae until it reaches desired height
What is considered in the Pink Aesthetics score?
- Mesial papilla
- Distal papilla
- Soft tissue level- is graft required
- Soft tissue contour
- Alveolar process deficiency
- Soft tissue colour
- Soft tissue texture
Aiming for this to be stable long term
What is the normal distance from alveolar bone to gingival margin?
3mm
What is the normal distance interproximally from crest of alveolar bone to contact point? What is different about implants
5mm- if less than this then soft tissue fills space well
In implants it is more common to get black triangle- not as high of a soft tissue collar between IP bone and contact
How can concavity in labial plate affect aesthetics of implant?
Depression in cervical region and incorrect height of zenith
How do we achieve aesthetic results when 2 implants are placed to replace missing centrals?
2mm from head of implant to gingival margin
1.5mm away from adjacent teeth (causes crater to develop- if too near can cause recession) and 3mm between implants
If distance between IP contact is more than 3.5mm it is likely to cause black triangle
-> If slight it can be acceptable
What are the common causes of compromised implant tissue sites?
Post extraction defects
Trauma
Hypodontia- bone never developed in first place (lack of hard and soft tissue)
Periodontal disease- significant amount of bone loss
Thin biotype- unstable soft tissues are more likely
What are the determinants in aesthetic outcome for implants?
- Bone volume and morphology
- Space dimensions- for health and aesthetics
- 3D implant position- optimal
- Take account of biotype- if thin consider grafting at time of implant placement
- Operator skill and experience
- Biological limits- explain this to patients
