Separated Instrument And Apical Pathology @ UL2

UL2 has apical periodontitis associated with 4-5mm of sectional silver point in the apical portion of the root canal.

Apical to this is either sealer or gutta percha. The tooth is a post crown abutment for a bridge replacing the UL3.

The risks associated with removal of the bridge and post favoured a retrograde approach for the retrieval of the instrument.

Assessment Of Surgical Site And Flap Design

There has already been some gingival recession associated with abutment @ UL2 and crown @ UL1.

A Ochsenbein-Luebke flap was considered the most practical. This photograph was taken after administration of local anaesthetic solution.

Incision

An incision is made with an SM69 surgical blade in a micro-scalpel handle. Reflection is made with a Pritchard periosteal elevator.

The flat highly polished end of the Pritchard elevator, when used as a mirror, is a valuable adjunct for indirectly visualising the operating field.

Location Of Root Apex

The root apex is located by estimating of the length of the tooth from a preoperative radiograph.

The bony topography is assessed to determine the likely location of the root apex. Bone is gradually shaved from the intended surgical area with an SM61 micro-scalpel blade until the apex is located.

Apical Access And Curettage

Any granulation tissue located in the surgical site is removed with excavators and curettes. The surgical access is further improved by bony removal with rotary instruments.

In order to reduce the risk of iatrogenic damage, the burs are directed away from the apex towards the periphery.

Access To The Root Canal

The remaining root canal filling is removed using a piezoelectric retrograde ultrasonic tip.

The irrigant is hypochlorous acid [Sterilox], maximising disinfection and debridement of the site. Ultrasonic tips are approximately 0.25mm in diameter and about 10% the size of a conventional microhead handpiece.

Location Of Sectional Silver Point

High powered magnification allows the operator to easily locate and clearly visualise the tip of the sectional silver point.

Notice that there has been no bevelling or instrumentation of the root apex thus maintaining the natural apex morphology.

Dislodgement Of Sectional Silver Point

The retrograde tip is used to energise the silver point encouraging its expulsion from the root canal.

Hypochlorous acid is used throughout the procedure as a coolant for the tip and to promote disinfection of the operating field.

Removal Of Sectional Silver Point

Under the high levels of magnification and the intense illumination afforded by the microscope, the sectional silver point is easily visualised.

It is effortlessly retrieved from the root canal.

Intracanal Preparation And Refinement

The root canal is further refined in its bucco-palatal dimensions to incorporate any accessory canals.

The apex of the tooth however, if not diseased, is treated sympathetically. It is neither shortened nor bevelled.

Obturation with Mineral Trioxide Aggregate [MTA]

The cavity is dried using micro-suction [Luer Vacuum Adapter and EndoEze tip Ultradent]. White MTA is delivered using an MTA Carrier and plugged incrementy using a P1 plugger.

It is important not to allow the MTA to dry out. If overly dry the MTA will not set. It will remain granular and fail to seal the apex.

The Retrograde MTA Filling In Situ

Additional increments of MTA are added until it is packed flush with the root apex. MTA has excellent biocompatibility and its ability to seal is not affected by blood contamination.

Wherever possible however, the operating field should be kept blood free using micro-suction.

Suturing

The mucoperiosteal flap is closed with 6/0 prolene sutures using microsurgical needle holders and scissors.

These sutures are removed after four days to prevent gingival overgrowth that hinders their easy removal.

Post Operative Radiograph

The post operative radiograph clearly shows 5mm of densely packed retrograde MTA in the apical third.

The objective is to completely obturate all the empty space up to the post. Careful preparation with the microscope has enabled the root apex to be sympathetically treated.

It remains unmodified and the root has not been shortened: A common consequence of apical surgery.

Two Months Post Operatively

Clinically the surgical site is healing satisfactorily. Notice the absence of further recession.

This is due to the use of a Ochsenbein-Luebke flap for gaining access to the root apex.