A conventional cantilever bridge I provided for a patient recently.

Although each mouth is individual it is important in order to obtain informed consent from a patient, to be honest and clear about the lifespan of dental restorations. This means that you need to use 'Evidence Based Dentistry' when educating patients. 
This shouldn't be interpreted by patients as a warranty, but as a guide. 


Here is a summary of the most common dental restorations based on current scientific literature:

Fillings

Amalgam - 90% still in place after 10 years. High copper based amalgams have better survivals

Composite - Mostly tested in cervical regions where failures are greater, better survival with enamel etching

Inlays

Tooth coloured - no difference between composite and porcelain survival rates, both more than 5 years

Gold - 99% present at 20 years, 75% at 25 years

Crowns

All ceramic - there isn't much long term data available at the moment, but Procera crowns have 94% still present after 5 years, Inceram have 94-98% after 3 years and Empress have 95% after 2 years.

Single crowns - mean survival is 9.5 years, but remember this is including all data. As I said in one of my previous posts here on extra-coronal restorations, the mean survival of NHS crowns is only 2 years!

Gold crowns - consistently good performance, around 16 years.

If teeth are root filled post-cementation, there are greater chances of failure.

Loss of vitality after crowning is around 15% after 5 years.

Porcelain Veneers

91% are still present after 10 years, with a greater failure rate if they are partially bonded to dentine.

Bridges

All Bridges - 85% are still present at 10 years which reduces to 65% at 15 years. There is no significant difference between cantilevers and fixed-fixed.

Adhesive Bridges - Average lifetime is 9.8 years but the greater the number of abutments, the greater the risk of failure.

Root Canal Treatment

Studies vary from 53-95% success rate and it depends heavily on tooth selection as well as operator experience.

The presence of a peri-apical area of infection lowers the success rate by 10-20%

Implants 

Figures vary from 82-99% success rate over a mulit-year analysis.

The most successful area for implants is the lower anterior region, whilst the worst are any areas that required grafting.