Achieving profound anaesthesia is important for the provision of pain free dentistry. This challenges is considered to be greatest is lower molars with irreversible pulpitis. It has been suggested that the use of premedication with non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen (paracetamol) although trials have produced conflicting results.

The aim of this review was to assess the efficacy of pre-emptive oral administration of single dose of non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen on the local anaesthetic success in adults with irreversible pulpitis and to find the possible covariates that could predict treatment effect.

Methods

Searches were conducted in the Cochrane Databases for Systematic Review, Pub Med, Science Direct, Scopus, and Google Scholar. Randomised placebo controlled trails evaluating the efficacy of pre-emptive analgesic on anaesthetic success were considered. The primary outcome measure was the success rate of anaesthesia within 15 min of administration of anaesthetic agent. Successful anaesthesia defined as no or mild pain on access cavity preparation and instrumentation that was determined either by tooth sensitivity level (TSL), or visual analogue scale (VAS).

Two reviewers selected studies abstracted data and assessed study quality using the Cochrane risk of bias tool.  Odds ratios (OR) were used for the outcome anaesthetic success and summarised using a fixed and random-effect inverse variance statistical method.

Results

• 16 RCTs  involving 1900 patients were included.
• Analgesics used were ibuprofen, indomethacin, ketorolac, meloxicam, acetaminophen, diclofenac potassium, aceclofenac, lornoxicam, piroxicam, etodolac, and paracetamol(acetaminophen).
• Dosages varied are were administered as a single dose 30, 45, and 60 min preoperatively.
• Patients who received pre-emptive analgesics reported significantly greater success rate of anaesthesia, as compared to placebo groups  OR = 0.30, (95CI%; 0.24 to 0.39, p = 0.000)

Subgroup analysis	Odds ratio ( 95% CI)
Administration of NSAIDs as monotherapy	0.25 (0.16 – 0.38)
Pre-treatment with ibuprofen as a monotherapy	0.44 (0.26 – 0.75)
Pre-treatment with ibuprofen as a combination therapy	0.48 (0.30 – 0.74)
Acetaminophen as combination therapy	0.30 (0.14 – 0.63)

• There was no significant difference in increasing anaesthetic success between treatment and placebo arms when acetaminophen was administrated alone.

Conclusions

The authors concluded

The present study showed that in patients with irreversible pulpitis, premedication with single analgesics is an effective strategy to improve anaesthetic success. To maximize the therapeutic effect, it is recommended to prescribe certain types of NSAIDs (indomethacin, meloxicam, and piroxicam, and diclofenac potassium), co-administration of acetaminophen and opioid, as well as administer articaine as local anaesthetic.

Comments  

A good search strategy has been employed for this review and a number of good RCTs have been identified. One earlier review of this topic published in 2011 (Other references) had similar findings while another found no benefit. The current review includes several studies published since 2011 and the results demonstrate that preoperative analgesia did improve anaesthetic success overall. However, as many of the studies used ibuprofen some caution regarding the subgroup analysis is advised as so of the analgesics were only used in a small number of studies. Likewise as all but two of the studies used lidocaine as the anaesthetic agent the recommendation regarding articaine should also be considered cautiously.

Related to this review is a recently published Cochrane review (Other references) looking at the effects of pre-operative analgesics on post-operative pain in children found insufficient evidence.

Links

Primary paper

Shirvani A, Shamszadeh S, Eghbal MJ, Marvasti LA, Asgary S. Effect of preoperative oral analgesics on pulpal anesthesia in patients with irreversible pulpitis-a systematic review and meta-analysis. Clin Oral Investig. 2017 Jan;21(1):43-52. doi: 10.1007/s00784-016-1974-1. Review. PubMed PMID: 27837343.

Other references

Dental Elf – 15^th Aug 2015

Do analgesics before dental treatment reduce post treatment pain in children?

 

Dental Elf – 29^th Sep 2011

Preoperative ibuprofen and acetaminophen did not improve inferior alveolar nerve anaesthesia success in patients with pulpitis.

 

Dental Elf – 23^rd  Jul 2011

Preoperative NSAIDs improve local anaesthetic success for root canal treatment of mandibular teeth