Can my bridge be damaged if a root treatment is to be performed the dentist wants to drill through the bridge as i have an abcess front teeth?

Root canal treatment: Doing root canal to a tooth by opening a hole in a crown definitely well compromise the well fare of the bridge to a certain degree . It depends on how that hole will be sealed after finishing the root canal and what material would be used.

Damage to bridge: Yes it is possible that your bridge may get damaged due to the drilling of porcelain in order to get to the tooth. This should be in your consent form that you read and sign before your dentist starts drilling.

Yes: There is no magic yes drilling through your bridge will creat a hole through it and that may be your only option.

Can? No, it WILL: Damage your bridge. The bridge is to your tooth as a roof is to your house. If you have a problem under it, it must be removed or cut through to access and remedy the problem. Once the root canal treatment is completed , the access hole cab be "sealed' temporarily, but you must replace the bridge eventually--preferably before the leaking seal material contaminates the root canal again.

RCT through bridge: Obviously, drilling a hole through the back of a crown will create a break in the integrity of the restoration. In doing so, there is always a risk of further damage to the porcelain which might necessitate remaking the entire bridge. What your dentist proposes is quite common. If everything goes well, your dentist will permanently seal the hole after the rct is completed. Then remake?