Materials and Method:

  • 84 patients with acute irreversible pulpitis in a lower first molar tooth
  • Randomly assigned to three groups of 28 patients each: → Group I - IAN block with 1.8 ml of LA soln* → Group II - IAN block with 3.6 ml of LA soln* → Group III - 1.8 ml as an IAN block PLUS 1.8 ml as a buccal infiltration

Materials and Method (Continued):[^9]

  • Used Lignocaine 2% + 1:80,000 adrenaline
  • Visual analogue scale to rate pain: → Pre-operative - before LA → At 15 minutes after LA injection → During access cavity preparation → During instrumentation of root canals
  • Cold pulp sensibility test 15 mins after injn
  • Data analyzed by chi-square, ANOVA, Kruskal-Wallis, and Mann-Whitney tests

OS:OM:OP:OR:Endo 2010;109:468–473

Results:[^10]

  • Pre-op pain scores - no sig. diff. → Group I - 117.2 ± 29.9 → Group II - 119.2 ± 22.8 → Group III - 112.8 ± 30.4

Overall Success

GroupTechniqueNo Pain
I1.8 ml IAN Block14.8%
II3.6 ml IAN Block39.3%
III1.8 ml IAN Block + 1.8 ml Bu Infiltration65.4%
Sig. Diff
OS:OM:OP:OR:Endo 2010;109:468–473

No. of patients with pain at each stage and overall success[^25]

  • Overall 49 (60.5%) pt’s had inadequate anaesthesia
    • Only 17 responded to a cold pulp sensibility test 15 minutes after injection
      • → More in Group I
    • 32 pt’s had pain when access cavity prepared
      • → Despite no response to a cold pulp test
      • → Group II - more when the pulp chamber was entered

OS:OM:OP:OR:Endo 2010;109:468–473

Discussion:[^11]

  • Combining an IAN block with a Buccal infiltration provided more effective LA for acute irreversible pulpitis in lower molars
  • Pulp testing after LA is not necessarily an indication of adequate pain control → Dentists need to be aware of the possible need for extra pain control strategies
  • Group II better than Group I - but not sig. diff. → Greater volume of LA solution helps a little → But an alternative injection site was more effective
    • Targets different nerves which may be involved in the pain sensation process