I applaud the comments previously stated from my fellow dentists and agree whole heartedly.  But another consideration is this: this rulemaking petition teeters on a very slippery slope.  I am gravely concerned about these types of provisions and the subsequent impacts that will follow.  As previously stated, there are too many factors to consider - many of which are completely beyond the dentist's control - when determining the longevity of any treatment; crown and bridge or otherwise.  Each patient is an individual with individual circumstances that may dictate the predictability and longevity of any treatment (a "crown" for one patient can be and many times is different than a "crown" on another).  Not to mention the patient's own treatment desires / choices when given multiple options.  I agree that there are existing provisions in place that patients can pursue should a treatment issue arise and that mandating some sort of warranty on treatment is completely unjustified.