The Influence of the Prosthetic Material and Prosthetic Design on the Clinical Outcomes of Implant-Supported Multiple-Unit Restorations in the Posterior Area

Consensus Statement 1: Implant-supported multi-unit restorations, i.e. splinted crowns or fixed dental prostheses with pontic units, in the posterior area are both well documented and reliable treatment options exhibiting high 3-year survival rates ranging from 97%-100% regardless of the materials used. The material combinations analyzed were porcelain-fused-to-metal, veneered, micro-veneered and monolithic zirconia, and monolithic lithium disilicate. Based on 22 prospective cohort studies and 7 retrospective case series

Consensus Statement 2: The prosthetic design - whether using splinted implant crowns or implant-supported fixed dental prostheses with pontic units - for the restoration of multi-unit posterior edentulous sites, does not significantly influence 3-year clinical outcomes in terms of survival and technical complications rates. Based on 10 prospective cohort studies and 6 retrospective case series

Consensus Statement 3: Monolithic and micro-veneered zirconia implant-supported multi-unit restorations with pontic units exhibit superior performance compared to porcelain-fused-to-metal and veneered zirconia in the posterior area in terms of annual ceramic fracture and chipping rates. No applicable data is currently available for monolithic lithium disilicate implant-supported multi-unit restorations with pontic units.Based on 11 prospective cohort studies and 6 retrospective case series.

Consensus Statement 4: When splinted implant crowns are made of monolithic and micro-veneered zirconia, they exhibit superior performance when compared to porcelain-fused-to-metal, veneered zirconia, and monolithic lithium disilicate in the posterior area in terms of annual ceramic fracture and chipping rates. Based on 12 prospective cohort studies and 3 retrospective case series.

1) What prosthetic design is recommended to treat multiple missing teeth in posterior edentulous sites with a fixed implant restoration?

Both splinted implant crowns and implant-supported multi-unit restorations with pontic units can be recommended to replace multiple posterior missing teeth.

2) How many implants you need to support a fixed restoration to replace at least three missing teeth in the posterior area?

To minimize invasiveness and treatment cost, it can be recommended to reduce the number of implants by restoring multiple posterior missing teeth with implant-supported fixed dental prostheses with pontic units as long as the mechanical properties of the restorative material and the implants can be respected (e.g. three-unit iFDPs on 2 implants instead of 3 splinted implant crowns).

3) What restorative material of choice for posterior multi-unit fixed implant-supported restorations?

In the posterior area, monolithic zirconia is recommended as the material of choice for implant-supported posterior multi-unit restorations in order to reduce technical complications such as ceramic fracture and chipping. The evidence supporting this recommendation is based on studies reporting on 3Y-TZP zirconia with a flexural strength >1000mPa or multi-layered (3Y-TZP / 5Y-TZP) alternatives.

4) What must be considered when using zirconia for implant-supported multi-unit fixed dental prostheses?

The clinician and the dental technician need to be well-informed and should select the restorative material for every indication as a team. Even though zirconia is the best-documented ceramic material for posterior multi-unit restorations, it has to be considered that various types and generations exist. The significant differences in optical and mechanical properties have not all been validated in clinical studies.

1) I am missing my upper-right back teeth. Can I have fixed teeth again?

Yes, if the circumstances are right we can provide you with a fixed solution on implants. Depending on what you would like, your anatomy, health and budget, we can determine how many teeth need to be replaced and how many implants will be needed. Based on scientific evidence

2) I have lost three teeth and want to replace them all. How many implants do you think I will need?

We have the choice between placing two or three implants to support three fixed teeth. In general, we recommend placing just two implants to support a three-unit bridge. This will make the surgical procedure easier, reduce the cost and the expected outcome is the same. Based on scientific evidence.

3) I guess the material needs to be quite strong if there is a non-supported tooth in the middle. What material do you use to make a bridge like that?

Today, the material of choice for this type of bridge is monolithic zirconia. Since it is made entirely out of high strength ceramic, there is less chance of the surface breaking or fracturing. Based on scientific evidence.

4) Does monolithic zirconia look like a natural tooth?

Today’s zirconia comes closer to imitating the look of a natural tooth. We can also further improve the parts that are visible when you smile by applying a thin layer of color to the surface of the zirconia. Based on scientific evidence.