TOOTH TO IMPLANT CONNECTION

How to think?Prepared by

Dr.Yamen Nouh

When do we need?

• Mesial drifted teeth leaving limited space to second implant

• Failed implant between teeth and succeeding implant

• Insufficient bone with no possibility for graft

• Patient cannot afford graft or multiple implants

What is the problem?

differences

• Tooth attachment with PDL acts as viscoelastic shock absorber

• Thus decreasing the amount of stress distributed to surrounding bone especially in Crestal area.

• And allowing higher degree of movement (up to 20 times more)

Main differences:Tooth

• Implant direct connection to bone (Osseointegration) is rigid.

• Allowing less movement and absorbing much less stresses.

• Conduction of stresses to bone.

• Concentrating forces at the crestal bone as it is the hinge point in case of lateral forces

Main differences:Implant

So...For the implant

Common..

Rare..

For the bridge (Very rare)

Follow up results

How to think: factors to consider

• Tooth mobility: teeth should not be mobile, if it is, it should be treated as splinting case (Add more implants to splint). Consider stress breakage design options.

• level of parafunctional activity

• number of implants and teeth being used in the restoration.

1- increase number of implants

• Increasing resistance arm (increasing implants to teeth ratio) in a way that makes the prosthesis does not need the teeth for support

2- Don’t use implant as pier

Connect only with healthy teeth

• In terms of periodontium and supporting bone

Decrease lateral forces

Amount of axial movement for teeth: 8-28 micronAmount of lateral movement for teeth: 65-108 micron

Amount of limited movement for implant: 0-5 micron

A- avoid in patients with para-functional stresses

B- Avoid in cases with high crown root ratio

C- connect implant to distal rather than mesial teeth

(and posterior rather than anterior)

Rigid or non rigid connection?

Use non rigid connection

non rigid connection allows teeth to move and act as stress breaker..

But..

Allowing intrusion

- The rate of intrusion is between 3-5.2%

- It jumps to 50% in case of para-functional habits

- Different theories for intrusion - Effect of Rachet: teeth not returning to its position due to friction between connector parts

Modification on non rigid connector

N.B: Need to be only in short span cases as if it is long span this will increase stresses on the connector

Use of rigid connection

• Tooth-tooth cemented bridge has the same mobility rate as tooth-implant connected bridges as declared by finite element analysis

• Also permanent cementation prevents intrusion.

Rigid connectionNon Rigid connection

- Allow teeth intrusion- Decrease bone

resorption

- Prevent teeth intrusion- May cause relatively

more bone resorption

Permanent cementation

To prevent teeth intrusion

• Half crown design

Say YES or NO and WHY in the following cases:

case 1

Case 2

Case 3

Case 4

case 5

Case 6

case 7

Case 8

Final conclusion!!!!

References..

• Spear, frank (2015). speareducation.com. Connecting Teeth and Implants: Yes, No, Maybe?. Retrieved from link

• Serhat Ramoglu, Simge Tasar, Selim Gunsoy, Oguz Ozan, and Gokce Meric, “Tooth-Implant Connection: A Review,” ISRN Biomaterials, vol. 2013, Article ID 921645, 7 pages, 2013. doi:10.5402/2013/921645