What are the alternatives to getting a crown put on a tooth?

A really big filling: The crown probably is the best long term treatment. The other option will be a big filling which is not as strong as a crown. See a dentist for an evaluation.

Big filling: Normally a dentist will recommend a crown when there is a chance your tooth may fracture. A big filling can help to replace the missing tooth structure but it will not help against fracture. Sometimes if a tooth fractures we can still do a crown to save it but sometimes we can't. If you don't get a crown your are taking a chance of losing the tooth.

Bondo: If you need a crown their is a reason. An alternative is a large filling. This may or may not be an option in your case. A large filling or "bondo job"will not have a very long lifespan.

Onlay: A tooth may need a crown because of a crack or a large cavity in it. If the damage is localized to part of the tooth, then an "only" can be made. It is more of a partial crown that helps preserve as much remaining solid tooth structure as possible. Another alternative is to have all of your old dental work checked to make sure cracks are not starting. A cosmetic dentist will make a great one.