Implant restorations 1

Question 1

What is used to ensure that the correct emergence profile of implants is created?

Answer 1

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.

Question 2

Why is occlusal adjustment for implants especially important?

Answer 2

It is hard to notice occlusal overload on dental implants because they do not have mechanoreceptors

Question 3

What are the common risks related to teeth connected to implants prostheses?

Answer 3

Not recommended because they deal with forces differently.

More stress around the implant

Bone loss

Fracture of components

Question 4

What risk is there if a freely moveable connector is used to connect the pontic to the natural tooth?

Answer 4

Tooth intrusion.

Question 5

What should be considered when using tooth-implant supported fixed partial dentures?

Answer 5

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

Question 6

What should be considered when using cantilever pontics connected to implants?

Answer 6

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

Question 7

When are cantilever implants contra-indicated?

Answer 7

Posterior cantilevers if they are single abutted

Question 8

When are cantilever implant supported bridges most commonly used?

Answer 8

Lateral incisor from canine

Lateral incisor from central incisors

Question 9

How should occlusion be adjusted for implants?

Answer 9

Keep slight contact on centric occlusion

Cannot be utilized in any excursive movements

Question 10

How is a complete edentulous arch replaced?

Answer 10

Hybrid denture that replaces missing tooth, gum, and lost bone around the teeth.

All-on-four

All-on-six

Question 11

How can implants be positioned in an overdenture to be safe for the patient?

Answer 11

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.

Question 12

What possibilities are there for fixed prosthesis with implants?

Answer 12

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

Question 13

Which is more ideal cement-retained or screw-retained fixed implants?

Answer 13

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

Question 14

What are the kinds of cementable abutments?

Answer 14

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.

Question 15

When do we use two-piece abutments?

Answer 15

When the tooth needs to be tilted in either direction.

Question 16

How do stock and customized abutments compare in protection of bone level?

Answer 16

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.

Question 17

How does the biological width protect the bone level in normal tooth compared to in implants?

Answer 17

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.

Question 18

What are the types of screw-retained fixed prostheses?

Answer 18

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.

Question 19

What are the advantages of using cement-retained abutments?

Answer 19

Improved direction of load

Enhanced aesthetics

Lowest risk of ceramic fracture

Lower cost

Less screw loosening

Question 20

What are the advantages of screw-retained abutments?

Answer 20

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

Question 21

What are the indications for cement retained implants?

Answer 21

High aesthetic demand

Question 22

What are the indications for screw-retained implants?

Answer 22

Low interarch space

Multi-teeth restorations

Question 23

What are the types of impression technique used for implants?

Answer 23

Close tray impression (snap-on impression)

Open tray impression (screw retained)

Question 24

What should be ensured when taking impression for implants?

Answer 24

Confirm correct seating of the impression abutment using a radiograph

Question 25

How is an open tray impression done?

Answer 25

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.