Prospective Healing Assessment After Application of Endodontic Microsurgery for Elimination of Apical Pathology By Use of Either a Rotary Bur for Osteotomy and Apical Root Resection, or Piezoelectric Unit for the Same Clinical Procedures

The aim of this study is to prospectively compare postsurgical healing after the use of microsurgical technique to eliminate apical pathology, either by use of rotary burs for osteotomy and root resection, or by use of piezoelectric surgery for the same clinical procedures. Null hypothesis is that there is no difference in healing and buccal bone thickness reformation between the two surgical procedures Another purpose of the study is to prospectively evaluate healing after the application of a novel buccal bone preservation technique, called the 'bone window' technique. The technique will be applied in a subgroup of patients on maxillary and mandibular premolar and molar teeth with an intact buccal cortical bone and healing and buccal bone reformation will be assessed at follow up. Null hypothesis in this part, is that there is no difference in healing and buccal bone preservation between osteotomy with a bur and the 'bone window' technique.