Thermoplastic obturation (702HFigs. 12.25 and 703H12.26).
Warm gutta percha techniques offer the possibility of extremely rapid and dense
obturation of the most irregularly shaped spaces.
- Dry the canal and lightly coat its walls with a slow setting sealer;
- Inject thermoplastic gutta percha into the apical portion of the canal and condense;
- Radiograph to check apical GP is in the correct place;
- Back-fill with GP and seal access cavity with an adhesive restoration.
While allowing dense and controlled canal obturation, the root-end closure procedure
adds nothing to the canal wall thickness or mechanical strength of immature teeth.
The final restoration should therefore be planned to optimize the durability of the
remaining tooth structure. Dentine bonded composite resins may be particularly
helpful in this regard, especially if extended several millimetres into the root canal to
provide internal splinting. The advent of light-transmitting fibre posts opens new
potential for rehabilitation and also provides a ready patency for canal re-entry if
needed. Periodic clinical and radiographic review should be arranged.
Alternatives to the root-end closure procedure
- Recently the potential has arisen to seal open apices with mineral trioxide aggregate
(MTA). Based on Portland building cement it is packed into the canal with pre-
measured pluggers and sets to form a hard, sealing, biocompatible barrier within 4 h.
Moist cotton wool is placed into the canal to promote setting and the material is
checked after at least 24 h before filling the remainder of the canal with gutta percha
and sealer, or with composite and a fibre post. Clinical studies are ongoing, but this
material seems likely to allow root end closure in 1 or 2 visits which will demand less
patient compliance (704HFig. 12.27). - When pulp vitality is lost in an almost fully formed tooth, it may be possible to
avoid lengthy root-end closure procedures by creating an apical stop against which a
root filling may be packed. Following crown to apex preparation as described above,
endodontic hand files may be used in gentle watch-winding or balanced-force motion
at working length to shave an apical seat for canal obturation. Alternatively, MTA can
be packed into the apical 1-2 mm of the canal with pluggers to provide an immediate
apical seal. - Endodontic surgery with root-end filling is becoming less popular as a means of
treatment in the case of non-closure. However, it may be considered to address
problems of serious, irretrievable overfill which may arise if the calcific barrier was
erroneously diagnosed as complete, or if the barrier was broken by heavy-handed
obturation.
Uncomplicated crown-root fracture
After removal of the fractured piece of tooth these vertical fractures are commonly a
few millimetres incisal to the gingival margin on the labial surface but down to the
cemento-enamel junction palatally. Prior to placement of a restoration the fracture
margin has to be brought supragingival either by gingivoplasty or extrusion
(orthodontically or surgically) of the root portion.