To ask the question until the patient's honestly when they come into our practice is not if our work will be replaced it's when and we always always always want to leave something for somebody to pick up versus the disheartening situation. Where we have no options for patients anymore that is the classical version of radically reduced UV black principles of undercutting destroying. To structure for retention which ultimately leads to more aggressive procedures of problems of canal therapy of cervical he fractured tooth of screwing posts that create stress. Of roots that are fractured now require extractions which really on my career we did removable partial dentures more full dentures at large on the populations that were victims of dentistry. With no minimally invasive concepts of force into they were seen that disappear by and large it's kind of disappearing off for good reasons.