Current protocols for root-end management in apical microsurgery are described.
Rational of root end resection:
1- Removal of: pathological process, anatomic variations, operator errors in NSRCT, and soft tissue lesion,
2- Access to the canal system,
3- Evaluation and creation to an apical seal,
4- Reduction of fenestrated root apices,
5- Evaluation for an aberrant canals and root fractures.
Long or short bevel:
Short bevel is preferred due to:
– Short bevel (close to 0) is more conservative than long bevel (20 ⁰ -45⁰).
-Long bevel creates spatial disorientation making root end preparation away from the long axis of the canal.
-Short bevel allows inclusion of the lingual anatomy Less chance of incomplete resection in short bevel (lingual cusp or incomplete resection). Fig.1.
-Shorter bevel provides shorter cavo-surface margins between the isthmus Fig.2.
-Less exposed dentinal tubules.
Instrumentations and techniques: 3 essential burs are needed for RER and REP which are:
– No. 6 or 8 round bur: for osseous access and gross removal of the apex.
-Lindemann bone bur: for rapid hard tissue removal and cutting initial root bevel.
-#1170 or #1171 bur: for refinement of bevelled root. Fig.3.
-3 mm should be resected from the root apex.
Handpiece should not have any air exiting from it’s end side to not cause emphysema or air embolism.
To reduce heat: coolant must be applied + cutting must be performed with a light, brushing strokes.
All burs used in apical surgery must cut sharply and have flutes that are far enough apart to shed debris and avoid clogging to not cause unintentional over heating of tissue.