Sometimes the development of the tooth goes a little haywire and another tooth begins to develop within a tooth, but not completely. So we end up with this invagination leading to the pulp and sometimes it doesn’t completely close off. Such a situation set the pulp up for an early death as can be seen here by the lack of root development and divergent open apices. Here we have a a pretty large finding imaging wise and a swelling. We changed the calcium hydroxide medicine out over 5 months and ultimately filled the apical 5mm with MTA and then reinforced the rooth with a fiber post. At 4 years post op there appears to be complete radiographic clearing and retained radio-opacity from the calcium hydroxide.