04 Complications Related to Implant-Supported Restorations P2

Question 1

What are the most common complications regarding tooth supported single crowns ?

Answer 1

1. post-cementation endodontic therapy (3%) - first
2. porcelain fracture (3%)
3. loss of retention (2%)
4. periodontal disease (0.6%)
5. caries (0.4%)

Question 2

What are the most common complications regarding tooth supported FPDs ?

Answer 2

1. caries (18% abutments; 8% prostheses)
2. need for endodontic treatment (11% abutments; 7% prostheses)
3. loss of retention (7%)
4. esthetics (6%)
5. periodontal disease (4%) – difficult in maintainance
6. tooth fracture (3%)
7. prosthesis fracture (2%)
8. porcelain veneer fracture (2%)

• loss of retention (7%) - loss of retention from 1 abutment from a 3-unit bridge. The bridge is still there so you have a micro-movement with saliva and bacteria going in the abutment. So, you will need endodontic treatment. Use your dental probe to check this.

Question 3

Which of the above-mentioned complications do not apply to implant supported restorations?

Answer 3

1. Pulpal complications,
2. periodontal disease and
3. caries

Question 4

Would you recommend a tooth supported restoration to a periodontal patient?
What are the most important factors for long term success?

Answer 4

Yes, I would. The most important factors are oral hygiene and maintenance .

Question 5

Would you recommend an RPD to a periodontal patient? What would be your concerns?

Answer 5

Not the ideal option .

Concerns would be the risk for technical complications such as loss of retention , loss due to abutment fracture and material complications .

Question 6

What is the mean 10-year survival and success rate of tooth supported FPDs? What is the difference?

Answer 6

The mean 10‐year survival rate of conventional FPDs was 90% and mean success rate was 80% .

• Survival rate is whether the implant is there or not . When you lose the implant the survival rate drops.
• Success is whether there are biological or technical complications . Success rate is more important , compared to survival rate.

Question 7

Discuss the use of non-vital teeth as abutments.

Answer 7

They have been associated with increased loss of retention and fracture of teeth and cores .

Question 8

Which are the most common reasons for implant loss? Discuss why.

Answer 8

1. infection or contamination – failure of implant because the infected area will become inflamed and osseointegration will not occur
2. trauma from surgical procedures
3. interference with implant osseointegration due to inflammation
4. excessive or premature occlusal loading
5. traumatic forces in the early stage can lead to osseointegration failure
6. cement retention (excess cement)-> it allows elevated retention of a biofilm, and this acts as an idiopathic cause for early implant loss – it overfloods the area, so bacteria retention and inflammation

Question 9

Discuss the risk factors for implant loss.

Answer 9

1. presence of type IV bone – the softest bone so there is a higher risk of implant loss
2. occlusal loading
3. smoking
4. history of periodontal disease
5. parafunctional habits
6. radiation therapy

Question 10

When do we observe the majority of implant loss occurring?

Answer 10

Prior to functional loading

most implants are lost in the first phase of healing (maybe because you didn’t follow the protocol, the bone is softer, there wasn’t enough bone to implant contact or iatrogenic factors)

Question 11

What is the minimum thickness of bone necessary to prevent bone dehiscence around an implant?

Answer 11

Minimum 1 mm thickness of buccal/labial plate

Question 12

How would you define a malpositioned implant?

Answer 12

an implant placed in a position that creates restorative and biomechanical challenges

Question 13

What would be the reasons for placing an implant with poor prosthetic angulation?

Answer 13

Most common reason is the deficiency of the osseous housing around the proposed implant site .

• Bone resorption is observed in osseous remodeling following tooth loss, osteoporosis, orthopedic revisions, craniofacial defects, or post oral cancer ablation associated with surgery/ radiation

Implant malpositioning due to: bone deficiency, GBR wasn’t performed, no surgical guides, lack of skill to make GBR, not correct tx planning

Question 14

What would be the complications of such an approach?

Answer 14

Affects biologic , biomechanical , and esthetic result of implant rehabilitations.
It doesn’t only prevent adequate positioning of the final prosthetic restoration , but also results in compromised integration and subsequently a poor prognosis for the therapeutic outcome

(prosthetic complications, screw loosening, decementation, aesthetic problems -> difficulty in OH and biologic complications)

Question 15

How can this be prevented?

Answer 15

1. Proper tx plan,
2. skills and
3. augmentation procedures with the use of biomaterials, autografts or allografts

Question 16

“Together these studies indicate that after 5 years one may expect one in four implant‐ supported restorations to require some type of repair, whether minor, such as screw or abutment tightening, or major, such as entire restoration replacement.”
In your own words please describe how would you handle this issue in your practice. What would this mean for you as a clinician?

Answer 16

As with any prosthetic rehabilitation, it has limitations. Whether those are minor or major. Therefore, the patients need to be aware of such limitations before starting with the treatment and be discussed with their dental surgeon. Make sure you monitor your patient in order to check how the treatment goes. By doing this you will be able to detect early if anything comes up so there are higher chances to avoid replacing the entire restoration.