The goal of this clinical trial is to compare bone healing after using apical tooth microsurgery to remove root end infection, either by use of rotary burs for cutting bone and root end, or by use of piezoelectric surgery for the same procedures.
The main questions it aims to answer are:
* Is there a difference in bone healing and reformation between the two surgical procedures ?
* Is there a difference in bone healing between cutting the bone with a rotary bur and cutting the bone with the 'bone window' technique that uses piezoelectric unit ?