Re-Rx Intra-Op

Re-Rx Intra-Op

1. Dam

   • 1 study
     • Van Nieuwenhuysen JP 1994
       • sig higher success

2. Instrument

   • material
     • SS
     • NiTi
       • hand/rotary
         • Ng 2011
           • better success rates
         • Pettiette MT 2001
           • same success rates in 1o RCT
             • less procedural errors
   • Taper
     • SS
       • narrow
         • 1mm step back
           • 0.05
       • wide
         • 0.5mm step back
           • 0.10
     • NiTi
       • 0.2, 0.4, 0.6, 0.8 greater taper
         • Ng 2011 no sig effect on success

3. Irrigation

   • EDTA
     • Ng 2011
       • improved PA healing
   • NaOCl + EDTA
     • synergistic
       • bacterial load reduction
   • CHX 0.2%
     • Ng 2011
       • reduced success significantly
   • Fedorowicz 2012 Cochrane
     • No evidence for one over another

4. Apex

   • Extent
     • ESE
       • apical constriction
         • 0.5-2mm rad apex
     • patency
       • Ng 2011
         • two-fold reduction in the success if no patency
         • 12% reduction in the odds of success with every mm of the canal from the terminus that remained “uninstrumented”
   • Size
     • Ng 2011
       • Size 30
         • Irrigant in 27 Gauge needle
           • not larger unless anatomy dictates
             • 0.06 taper for NiTi
             • 0.05 taper for SS

5. Obturation

   • material
   • technique
   • apical extent
     • patency filling
       • Ng 2011
         • maintain opening of apex
           • 80% success strict criteria
   • quality

6. Intervisit Med

7. Flare Up

8. Number of Visits

9. Magnification

   • Ng 2011
     • insignificant influence on outcome.
     • assist in MB2 location (64%)