Implant restorations 1 Flashcards
What is used to ensure that the correct emergence profile of implants is created?
Diagnostic wax-up and surgical guide.
If the final position of the implant is not adequate, bone grafting can be used to create a better emergence profile.
Why is occlusal adjustment for implants especially important?
It is hard to notice occlusal overload on dental implants because they do not have mechanoreceptors
What are the common risks related to teeth connected to implants prostheses?
Not recommended because they deal with forces differently.
More stress around the implant
Bone loss
Fracture of components
What risk is there if a freely moveable connector is used to connect the pontic to the natural tooth?
Tooth intrusion.
What should be considered when using tooth-implant supported fixed partial dentures?
Mobility of the teeth connected with the implants.
Number of teeth and implants to be connected
Occlusal forces
Rigidity of the prosthesis
Type of connection
Type of bone
What should be considered when using cantilever pontics connected to implants?
Arch shape
Tooth
Length and diameter of the implant
Opposing occlusion
Edentulous ridge morphology
Soft tissue profiles
Aesthetics (best reason to use this)
Overall expectations of the patient
When are cantilever implants contra-indicated?
Posterior cantilevers if they are single abutted
When are cantilever implant supported bridges most commonly used?
Lateral incisor from canine
Lateral incisor from central incisors
How should occlusion be adjusted for implants?
Keep slight contact on centric occlusion
Cannot be utilized in any excursive movements
How is a complete edentulous arch replaced?
Hybrid denture that replaces missing tooth, gum, and lost bone around the teeth.
All-on-four
All-on-six
How can implants be positioned in an overdenture to be safe for the patient?
Posterior region must be given room to flex while chewing
Implants should follow the curvature of the arch and not be in a straight line. Cantilever must not be more than 1.5x the distance from the most distal implant and the most anterior implant.
What possibilities are there for fixed prosthesis with implants?
FP-1: Replace only the crown. Similar to natural tooth.
FP-2: Replaces the crown and a portion of the root. Crown contour appears normal in the occlusal half but is elongated or hypercontoured in the gingival half
FP-3: Replaces missing crowns and gingival colour and portion of the edentulous site.
RP-4: Overdenture supported completely by implants
RP-5:Overdenture supported by soft tissue and implants
Which is more ideal cement-retained or screw-retained fixed implants?
If you want long term retrievability then screw-retained.
Cement-retained is like a PFM crown with metal coping and then ceramic over the metal
What are the kinds of cementable abutments?
Cementable abutments:
One-piece abutment: Solid with abutment + screw are one piece
Two-piece abutment: Abutment and screw are separate pieces
Stock abutments: Screw and abutment are separate (two-piece abutment) cannot change the contour of this abutment.
Customizable or anatomic abutments: Lab designs contour of the abutments. Lab will be given fake gingiva to use with the impression.
When do we use two-piece abutments?
When the tooth needs to be tilted in either direction.
How do stock and customized abutments compare in protection of bone level?
Stock abutment has to be subgingival in order to not compromise aesthetics but customized abutments follow the gingival margin making less excess cement reaching the bone level at the bottom of the gingival sulcus.
How does the biological width protect the bone level in normal tooth compared to in implants?
When an implant is placed, the cement can run along the gingival sulcus towards the bone and cause loss of bone structure due to inflammation.
What are the types of screw-retained fixed prostheses?
Direct screw-retained crown: Screwed into the implant and the crown is attached to the abutment
Indirect screw retained crown: Crown is screwed into the abutment and the abutment screwed into the implant. This can allow the crown to be cross pinned which allows screwing in a different direction and creating better aesthetics when an implant isn’t placed in a good location.
What are the advantages of using cement-retained abutments?
Improved direction of load
Enhanced aesthetics
Lowest risk of ceramic fracture
Lower cost
Less screw loosening
What are the advantages of screw-retained abutments?
Low profile retention (no need to rely on interarch space to create retention of the crown)
Limited inter-arch space
No cement in sulcus
Retrievable
What are the indications for cement retained implants?
High aesthetic demand
What are the indications for screw-retained implants?
Low interarch space
Multi-teeth restorations
What are the types of impression technique used for implants?
Close tray impression (snap-on impression)
Open tray impression (screw retained)
What should be ensured when taking impression for implants?
Confirm correct seating of the impression abutment using a radiograph
How is an open tray impression done?
1) unscrew the implant
2) rinse out with chx
3) screw in implant
4) place stock tray over it and create holes where the stock tray touches the implants
5) Block out holes with wax.
6) Place light body material
7) Take impression with medium body.
