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O1A Pain Control during retreatment

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Pain Control During Endodontic Treatment1

Importance of Pain Control During Treatment2

  • Pain during treatment significantly impacts on the amount of post-op. pain

Info

==The more pain a patient feels during treatment, the more pain they will experience after treatment.==

Local Anaesthesia3

  • Three goals of local anaesthesia:
    • Anaesthesia during treatment
    • Haemostasis during treatment
    • Prolonged post-operative pain control

Local Anaesthesia3

Mechanisms of Pain Control

  • Pain control from local anaesthetics - two mechanisms:
    1. Direct: Block discharges from peripheral nerves
      • Duration: Minutes → Hours
    2. Indirect: Prolonged blocking of peripheral input reduces central sensitization
      • Duration: Hours → Days

Inadequate Local Anaesthesia

  1. Pain during treatment
  2. More post-operative pain
    • Since prolonged exposure to sensory input increases allodynia and hyperalgesia
  • ==Allodynia: Pain resulting from a stimulus that would not normally be painful.==
    • ==Hyperalgesia: An exaggerated pain response to a stimulus.==

Anaesthetic efficacy of the supplemental intraosseous injection of 2% lidocaine with 1:100,000 epinephrine in irreversible pulpitis4

25 Maxillary Teeth

Nusstein et al JoE 1998

graph TD
    A[Bu Infiltration Injection<br>Lignocaine + 1:100,000 Adr] --> B[No Response to PT's 92 %]
    A --> C[Responded to PT's 8 %]
    B --> D[No Pain 68 %]
    B --> E[Pain in Dentine 4 %]
    B --> F[Pain in Pulp 20 %]
    C --> G[Need supplementary LA techniques]
    F --> G

Conclusion

Even with a successful buccal infiltration in the maxilla, a significant portion of patients (24%) still experience pain during treatment for irreversible pulpitis.

26 Mandibular Teeth5

IAN Block Injection Lignocaine + 1:100,000 Adr

  • No Response to PT’s — 38 %
  • Responded to PT’s — 62 %
    • No Pain — 7 %
    • Pain in Dentine — 12 %
    • Pain in Pulp — 19 %
    • Need supplementary LA techniques

Conclusion

The IAN block has a very high failure rate for mandibular molars with irreversible pulpitis.

Why Does Local Anaesthesia Not Work with Acute Irreversible Pulpitis?

  • Various theories proposed — none proven
  • Most commonly discussed:
    • Inflammation activates nociceptors (pain receptors) and associated central pain mechanisms
    • Inflammatory mediators reduce threshold of nociceptor activation → So minor stimuli fire the neurons
    • Mediated by prostaglandins → Produced by arachidonic acid metabolism
    • Prostaglandins sensitize nerve endings → Enhances pain and inflammation
    • Inflamed pulps have high levels of both prostaglandins and arachidonic acid

Warning

==However, most of these theories focus on local factors around the tooth and fail to adequately explain why a block injection, administered several centimetres away from the site of inflammation, would fail.==

  • LA unable to block conduction of all nerve impulses → When pain present - have more impulses than normal
  • pH is more acidic in the presence of inflammation so LA is less effective
  • Spread of inflammation along myelin sheaths may restrict absorption of the LA solution
  • Increased vascularity increases blood flow and removes the LA more rapidly
  • Periapically, there may be stasis - reduced blood flow
  • Pain can neutralise the effects of LA in the CNS

Other Possible Causes

  • Insufficient dose
  • Incorrect injection site
  • Incorrect technique
  • Intravascular injection
  • Individual variation - anatomy, dosage, etc.
  • Variation in pain threshold and perceptions
  • Inadequate time for LA to work
    • ==This is a major factor. Dentists often wait only 3-5 minutes, but a block injection for a “hot” tooth may require up to 15 minutes to become fully effective.==

Continued Pain After LA Injection6

  • Three stages when pain may be felt:
    1. Pre-operative
    2. Dentine
    3. Pulp

**Strategies to Manage Acute Irreversible Pulpitis in a Lower Molar steps 1-3 out of 8 **7

  1. Pre-empt the difficult situation - i.e. Diagnosis !!
  2. Consider pre-medication with ibuprofen → Assuming no contra-indication
  3. Test tooth : triplex air + percussion during exam

The Effect of Premedication with Ibuprofen and Indomethacin on the Success of Inferior Alveolar Nerve Block for Teeth with Irreversible Pulpitis8

A randomized double-blind clinical trial investigated ibuprofen and indomethacin pre-medication for acute irreversible pulpitis in mandibular molars, focusing on an earlier stage of the condition.

Findings:

  • Cold sensibility tests were not perfect predictors of anesthesia effectiveness.
  • Ibuprofen and indomethacin significantly improved treatment success compared to placebo.

Discussion:

  • NSAID pre-medication aids in pain control, with ibuprofen being more effective and safer than indomethacin.
  • Efficacy hinges on the stage of pulpitis, with better results in earlier, less inflamed cases.

Acute Irreversible Pulpitis9

graph TD
    A[May or may not have pain to bite and percussion] --> B[?]
    B --> C[± Pain is spontaneous]
    B --> D[± Pain lying down]
    B --> E[± Pain wakes patient]
    B --> F[± Primary acute apical periodontitis]
    C --> G[Intense throbbing / aching pain; continuous or may come and go]
    D --> G
    E --> G
    F --> H[Pain to bite & tender to percussion]
    I[Pain with cold stimuli] --> J[Short, very sharp pain then lingering ache / throb]
    K[± Pain with heat] --> J

Conclusion of Premedication Study

  • Pre-medication with a single dose of Ibuprofen can help with pain control during treatment of acute irreversible pulpitis in mandibular molars → If there is no spontaneous pain
  • Highlights the need for a thorough history and diagnosis of the presenting complaint

Practical Challenge

The main practical challenge is scheduling the one-hour wait time for the premedication to take effect in a busy practice.

**Step 4: Gow Gates Block

The Gow-Gates Mandibular Block

Technique and Landmarks10

Target site: Lateral region of the neck of the condyle, just below the insertion point of the lateral pterygoid muscle

Goal

==To anaesthetise the entire mandibular nerve trunk after it exits the foramen ovale. This includes accessory branches that are often missed by a standard IAN block, which is why it is more effective.==

Entry point: Medial to the deep tendon of the temporalis muscle and slightly below the Palatal cusp of the UPPER 2nd molar

External landmarks: Apex of the intertragic notch and the lower border of the tragus through to opposite corner of the mouth

Advantages of the Gow-Gates Block1112

  • High success rate

    • GG: 92 - 99 % vs - IAN: 65 - 85 %

  • No supplementary injections needed

    • i.e. Do not need Long Buccal or Lingual nerve injections

  • Less muscle involved

  • Less painful

    • Even though larger needle used!

  • ==Requires about 15 minutes to take full effect==

    • This waiting time can be productively used for patient consultation.

  • A safer technique

  • Less blood vessels at injection site

    • Positive aspiration rate - negligible

  • No vaso-constrictor required

    • Use plain Prilocaine (e.g. Citanest 4%)
    • Only 1 carpule required (i.e. 2.2 ml)

Incidence of Grade “A” anaesthesia1314

Prilocaine , felyrpressin or just plain are all highly successful when doing a gow gates

**Step 5: Retesting after gow-gates block

  1. Re-test with triplex air and percussion → If no pain: place rubber dam and re-test !! → If still pain: Give IAN Block + Buccal Infiltration

Inferior Alveolar Nerve Block Hints15

Technique Tip

==The most frequent mistake in the gg-block is placing the needle too far distally. Using a short needle with a slight bend can improve control and help target the correct area. The historical fear of needle breakage at the hub is obsolete with modern, single-piece needle manufacturing.==

Efficacy of combining a buccal infiltration with an inferior alveolar nerve block for mandibular molars with irreversible pulpitis1617

Info

This indicates that adding a buccal infiltration is more effective than simply increasing the volume at the IAN block site. However, a 35% failure rate still exists.

Articaine vs. Lidocaine

==A review of the literature shows no significant advantage in using 4% articaine over 2% lidocaine for block anaesthesia in these situations. While some studies show a benefit for infiltration, its use for IAN blocks is discouraged due to its higher concentration (4% vs 2%) and the associated, albeit debated, increased risk of lingual nerve paraesthesia.==

** Gow-gates block Conclusions:**18

  • More effective LA for acute irreversible pulpitis in lower molars when an IAN block is combined with a Bu infiltration
  • However, some patients will still have pain !!

Supplementary Injections - Other Teeth19

  • Labial infiltration for lower anterior teeth

  • Palatal infiltration for upper molars

    • This is a highly effective supplement to a buccal infiltration because it directly anaesthetises the palatal root, which is often missed by buccal-only approaches.

  • Palatal for upper premolars and anterior teeth

    • Anterior middle superior alveolar (AMSA) nerve block

**step 8: re-test with triplex air and percussion

  1. 8. Re-test again with triplex air and percussion → If no pain: proceed with treatment
  • Turn the H/S handpiece water off !! → If pain: give PDL injection and test again
  • Can then normally cut enamel or restoration

Rubber Dam Cuff Technique20

Advantages:

  • Enables PDL injections if required
  • Full access to the entire tooth
  • Better vision

Periodontal Ligament Injection21

Mechanism

==The PDL injection is effectively an intraosseous injection that works very quickly (20-30 seconds). The anaesthetic is not intended to track down the ligament space. Instead, high pressure forces the solution through the porous cancellous bone of the socket wall to reach the apex.==

Technique

  • Place the needle into the gingival sulcus, angled into the PDL space.
  • ==The bevel of the needle must face the bone, not the tooth root.==
  • Inject with firm, steady pressure at 4-6 points around the tooth (e.g., mesiobuccal, distobuccal, mesiolingual, distolingual corners).
  • Only a very small amount of solution can be injected at each site.

Intra-osseous Injections22

Warning

While dedicated systems exist for direct intraosseous injection, they are less practical. They are difficult to use, cannot be administered with a rubber dam in place, and carry a risk of iatrogenic damage to the tooth root. The PDL injection is a simpler and safer alternative.

**Step 10 if pain is felt upon reaching pulp **

→ Intra-pulp injection

Intra-Pulp Injection23

Technique

==This injection is most effective when administered through a very small pulp exposure. The small opening allows for the creation of back-pressure, which forces the anaesthetic solution into the pulp tissue, achieving profound anaesthesia. It is recommended to give an intra-pulp injection proactively as soon as a pinpoint exposure is made. If the pulp chamber is widely opened, the lack of back-pressure renders the technique ineffective.==

**Step 11 : If patient is still in pain

→ Pulpotomy only - CS-AB dressing

  • ==The goal should shift from complete instrumentation to pain relief. Place a corticosteroid-antibiotic paste (e.g., Leder mix paste) over the canal orifices to control inflammation.==

    → Re-appoint - 3-4 weeks later

Pain Relief after Pulpotomy24

Success

A pulpotomy is highly effective for pain relief. One study found that it can reduce pre-operative pain by an average of 82% (from 100% down to 18%).

Acute Irreversible Pulpitis - Lower Molar Tooth (Flowchart)

flowchart TD
    A[Discuss Diagnosis, Treatment Plan, etc] --> B[TEST - Cold, Percussion]
    B --> C[Gow-Gates Mandibular Block]
    C --> D[TEST - Cold, Percussion]
    D --> E[Inferior Alveolar Nerve Block + Buccal Infiltration]
    E --> F[TEST - Cold, Percussion]
    F --> G[Periodontal Ligament Injection]
    G --> H[TEST - Cold, Percussion]
    H --> I[Intra-Pulp Injection]
    I --> J[Pulpotomy + CS-AB Dressing]

And …25

❌ Do NOT prescribe antibiotics !!!

  • AB’s are unnecessary and contra-indicated
  • AB’s are not pain relieving medications
  • AB’s do not help treat inflammation
  • Pulpitis is an INFLAMMATORY condition
    • Even though it is caused by the presence of bacteria in the tooth
    • And a systemically-administered AB will not reach the bacteria in in the caries, crack, restoration/tooth interface, etc.

Danger

==Prescribing antibiotics in this situation is inappropriate, ineffective (acting only as a placebo), and contributes to antibiotic resistance. Pain should be managed with analgesics and NSAIDs, not antibiotics.==

Summary26

  • Achieving adequate pain control is difficult, and unpredictable, when treating acute irreversible pulpitis
  • Dentists need various strategies to ensure good pain control for their patients
    • Before treatment
    • During treatment
    • After treatment

Summary of Management Strategy27

  1. Pre-empt the difficult situation
  2. Consider pre-medication
  3. Test tooth pre-op: → Triplex air + percussion
  4. Gow-Gates Block → Discuss treatment, etc.
  5. Re-test: triplex air + percussion → If no pain: proceed with treatm → Turn water off H/S handpiece → If still pain: Give IAN Block + Buccal Infiltration
  6. Allow more time for LA to work
  7. Place rubber dam - cuff tech.
  8. Re-test again: air + percussion → If no pain: proceed with treatm → Turn water off H/S handpiece → If pain: give PDL injection
  9. If pain felt on reaching dentine → PDL injection
  10. If pain felt on reaching the pulp → Intra-pulp injection
  11. If still pain → Pulpotomy - CS-AB dressing → Re-appoint - 3-4 weeks later

Post-Operative Follow-up

Timeline

  • 3-4 weeks later

Additional Instructions

  • ==Patients should be prescribed appropriate analgesics or anti-inflammatory agents (e.g., ibuprofen) for post-operative pain management.==
  • ==Patients should be explicitly told that antibiotics are not necessary or helpful for this condition.==

Footnotes

  1. Original PDF page 1: O1A Pain control During retreatment, p.1 ↩

  2. Original PDF page 2: O1A Pain control During retreatment, p.2 ↩

  3. Original PDF page 3: O1A Pain control During retreatment, p.3 ↩ ↩2

  4. Original PDF page 4: O1A Pain control During retreatment, p.4 ↩

  5. Original PDF page 5: O1A Pain control During retreatment, p.5 ↩

  6. Original PDF page 7: O1A Pain control During retreatment, p.7 ↩

  7. Original PDF page 14: O1A Pain control During retreatment, p.14 ↩

  8. Original PDF page 8: O1A Pain control During retreatment, p.8 ↩

  9. Original PDF page 13: O1A Pain control During retreatment, p.13 ↩

  10. Original PDF page 15: O1A Pain control During retreatment, p.15 ↩

  11. Original PDF page 16: O1A Pain control During retreatment, p.16 ↩

  12. Original PDF page 17: O1A Pain control During retreatment, p.17 ↩

  13. Original PDF page 18: O1A Pain control During retreatment, p.18 ↩

  14. Original PDF page 19: O1A Pain control During retreatment, p.19 ↩

  15. Original PDF page 20: O1A Pain control During retreatment, p.20 ↩

  16. Original PDF page 21: O1A Pain control During retreatment, p.21 ↩

  17. Original PDF page 22: O1A Pain control During retreatment, p.22 ↩

  18. Original PDF page 28: O1A Pain control During retreatment, p.28 ↩

  19. Original PDF page 29: O1A Pain control During retreatment, p.29 ↩

  20. Original PDF page 30: O1A Pain control During retreatment, p.30 ↩

  21. Original PDF page 31: O1A Pain control During retreatment, p.31 ↩

  22. Original PDF page 35: O1A Pain control During retreatment, p.35 ↩

  23. Original PDF page 36: O1A Pain control During retreatment, p.36 ↩

  24. Original PDF page 37: O1A Pain control During retreatment, p.37 ↩

  25. Original PDF page 38: O1A Pain control During retreatment, p.38 ↩

  26. Original PDF page 39: O1A Pain control During retreatment, p.39 ↩

  27. Original PDF page 40: O1A Pain control During retreatment, p.40 ↩

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