PainPhase 2NSAIDNCT02417337

Efficacy of Different Drugs to Control Post Root Canal Treatment Pain

A Phase 2 study testing Paracetamol, Ibuprofen and Mefenamic Acid in people with Pain and Postoperative Pain, run by University of Khartoum at 1 site in Sudan.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

Search all trials

Trial summary

Who is it for?: Ages 18 to 60 yearsHealthy volunteers can take part
Conditions the study is for: Pain, Postoperative Pain, Irreversible Pulpitis
What is being tested?: Paracetamol, Ibuprofen and Mefenamic Acid
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 185 participants
Where: 1 siteSudan
Study dates: Aug 2012to Jan 2015
Phase: Phase 2
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 60 years
All sexes
Healthy volunteers accepted
Adult

Who may be able to join

Spontaneous pain moderate to severe on the verbal rating scale (VRS-4), ranging from 4-10 score based on the numerical rating scale (NRS-11).
Adult patients presented for emergency endodontic treatment with a symptomatic maxillary or mandibular tooth (anterior and premolar) with a pulpal diagnosis of Irreversible pulpitis and normal periapex.
Patient choose to have root canal treatment for pain of endodontic origin.
The patient presented with American Society of Anesthesiologists (ASA) I or II medical history (ASA 1963).
The patient had read and thoroughly understood the pain score level sheet

Who cannot join

Patients below 18 years of age;
Analgesic taken within the last 4 hours;
History of allergy to NSAIDs, paracetamol or local anaesthetics;
History of uncontrolled systemic disease [gastrointestinal (GI) disorders, oesophageal reflux, active asthma, decreased hepatic function, haemorrhagic disorders, or poorly controlled diabetes mellitus].
Patients currently taking opioids, monoamine oxidase inhibitors, tricyclic antidepressants, carbamazepine, diuretics, or anticoagulants;
There was history of opioid addiction or abuse; and
Pregnant or nursing female patients.

Trial locations and contacts

1 site in 1 country.

Sudan1 site

University of Khartoum, Faculty of Dentistry,
Khartoum, 111-11

Other trials in Sudan

About this study

Official title: Efficacy of Pain Control Following Root Canal Treatment Using Paracetamol Alone and in Combination With Three Different Non-Steroidal Anti-Inflammatory Analgesics

Root canal therapy will ideally eliminate post-endodontic pain but occasionally analgesics are needed to diminish the pain [Owatz et al 2007]. Development of pain after completion of root canal treatment may undermine patients' confidence in the procedure and the clinician [Albashaireh and Alnegrish 1998]. Non-steroidal anti-inflammatory drugs are one of the most frequently taken analgesic medications for dental pain. Their popularity attributed to their efficacy in relieving pain and fever and low side effect profile at therapeutic doses [Attar et al 2008]. Mono-therapy analgesic has a low effect on dental pain. Improvement was performance by combining analgesics with different mechanisms of action without raising any adverse effects [Mehlisch 2002], was effective in controlling moderate to severe pain. The combination of a non-steroidal anti-inflammatory drug (NSAID) and paracetamol has shown additive analgesia for treating dental pain in several studies [Breivik et al1999, Keiser and Hargreaves 2002]. Endodontic treatment with a lower prevalence of postoperative pain is usually the treatment of choice.There have been no controlled dental studies evaluating the additive effects of combining a non-steroidal anti-inflammatory drug with paracetamol. Breivik et al1999 \& Menhinick et al 2004 found that a combination of acetaminophen and ibuprofen was more effective than ibuprofen alone in managing postoperative pain [Breivik et al1999 \& Menhinick et al 2004]. Aim of the present study, to evaluate the efficacy of the paracetamol when used alone and in combinations with three groups of drugs to control postoperative endodontic pain.

Read the detailed description

Background: Management of pain is challenging part of dental treatment; sometimes pain is a major postoperative symptom after many dental procedures especially for endodontics. The aim of the present randomized clinical trial was to investigate the efficacy of using paracetamol alone and three combinations of non-steroidal anti-inflammatory drugs with paracetamol, to control postoperative endodontic pain.

Methodology: 185 patients who had anterior or premolar teeth with irreversible pulpitis without any signs and symptoms of apical periodontitis and with moderate to severe pain. Patients were divided by allocation randomization into five groups. Four experimental groups receiving different medication; group I (single dose of paracetamol); group II (ibuprofen / paracetamol); group III (mefenamic acid /paracetamol), group IV (diclofenac k / paracetamol) and group V (no medication group). The groups received the medication after the first appointment where the pulp removed, and canals fully prepared. Pain intensity was scored by using both verbal rating scale (VRS-4) and numerical rating scale (NRS-11). The pain scores were recorded before the initial endodontic therapy for up to 8 hours postoperatively. Sign test used for comparing pain score before and after treatment. This randomized control clinical trial was conducted on patients who were considered potential candidates if they had moderate to severe spontaneous pain of odontogenic origin (ranging from 4-10 score based on the numerical rating scale (NRS-11)). Patients were selected from those attending the Conservative dentistry clinics in both the University and the Teaching Hospital Emergency Clinic.

The medications were prepared in the laboratories of faculty of Pharmacy. Four groups of medications were prepared and a placebo as follows; Group I: paracetamol 1000mg Group II: ibuprofen 600mg + paracetamol 1000mg, Group III: Mefenamic acid 500mg + Paracetamol 1000mg Group IV: Diclofenac K 50mg + paracetamol 1000 mg Group V: Placebo

Conditions: Pain, Postoperative Pain, Irreversible Pulpitis
Being tested: Paracetamol, Ibuprofen, Mefenamic Acid, Diclofenac, Placebo
Medical subject headings: Pain, Pain, Postoperative

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

ParacetamolDrug
Also called Acetaminophen
NSAID
IbuprofenDrug
Also called isobutylphenyl propanoic acid
NSAID
Mefenamic AcidDrug
Also called Fenamate
NSAID
DiclofenacDrug
Also called Voltaren
NSAID
PlaceboOther
Also called no medication
empty double gelatinous capsules, having similar weight and appearance of the medications

Study groups in NCT02417337
Study group	Role	What they receive
Group I	Active comparator	paracetamol 1000mg Receives: Drug: Paracetamol
Group II	Experimental	ibuprofen 600mg + paracetamol 1000mg, Receives: Drug: Paracetamol; Drug: Ibuprofen
Group III	Experimental	Mefenamic acid 500mg + Paracetamol 1000mg Receives: Drug: Paracetamol; Drug: Mefenamic Acid
Group IV	Experimental	Diclofenac K 50mg + paracetamol 1000 mg Receives: Drug: Paracetamol; Drug: Diclofenac
Group V	Other	Placebo, no medication Receives: Other: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

Pain Scores Before and After 8 Hours of Treatment Per Group on the VRS-4 Scale
Pain was recorded in the verbal rating scale-4 (VRS-4 scale) before and after 8 hours of medication. The VRS-4 Scale has four categories of pain scores: no pain is the minimum (better outcome), slight pain, moderate pain, and severe pain score is the maximum (worse outcome).
Measured: 8 hours
Pain Score on Numerical Rating Scale of Pain (NRS-11)
(NRS-11) numerical rating scale of pain between 0 (better) and 10 (worse) before and after treatment
Measured: 8 hours

Secondary outcomes (1)

Mean of Pain Reduction Stratified by Sex and Jaw Type on Numerical Rating Scale (NRS-11)
Numerical rating scale (NRS-11), (0 better/the least pain score to 10 worse/the maximum pain score), , was done for sex (male or female) and jaw type (maxilla or mandible)
Measured: 8 hours

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

Aug 2012Jan 2015

First posted15 Apr 2015 (estimated)
Study startAug 2012
Primary completionAug 2014
Study completionJan 2015

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (8)Papers the sponsor has linked to this study.
Other trials for PainStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 2
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 185 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT02417337
Sponsor's protocol ID: University of Khartoum
Acronym: NSAID
Status last verified: Aug 2026
First submitted: 30 Mar 2015
Last updated: 10 Aug 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
Individual data sharing: No: Not shared

Publications

Owatz CB, Khan AA, Schindler WG, Schwartz SA, Keiser K, Hargreaves KM. The incidence of mechanical allodynia in patients with irreversible pulpitis. J Endod. 2007 May;33(5):552-6. doi: 10.1016/j.joen.2007.01.023. Epub 2007 Mar 6.
PubMed 17437870
Albashaireh ZS, Alnegrish AS. Postobturation pain after single- and multiple-visit endodontic therapy. A prospective study. J Dent. 1998 Mar;26(3):227-32. doi: 10.1016/s0300-5712(97)00006-7.
PubMed 9594474
Attar S, Bowles WR, Baisden MK, Hodges JS, McClanahan SB. Evaluation of pretreatment analgesia and endodontic treatment for postoperative endodontic pain. J Endod. 2008 Jun;34(6):652-5. doi: 10.1016/j.joen.2008.02.017. Epub 2008 Apr 2.
PubMed 18498882
Mehlisch DR. The efficacy of combination analgesic therapy in relieving dental pain. J Am Dent Assoc. 2002 Jul;133(7):861-71. doi: 10.14219/jada.archive.2002.0300.
PubMed 12148679
Breivik EK, Barkvoll P, Skovlund E. Combining diclofenac with acetaminophen or acetaminophen-codeine after oral surgery: a randomized, double-blind single-dose study. Clin Pharmacol Ther. 1999 Dec;66(6):625-35. doi: 10.1053/cp.1999.v66.103629001.
PubMed 10613619
Keiser K, Hargreaves K.Building effective strategies for the management of endodontic pain. Endodontic Topics, Volume 3, Issue 1, pages 93-105, November 2002
Menhinick KA, Gutmann JL, Regan JD, Taylor SE, Buschang PH. The efficacy of pain control following nonsurgical root canal treatment using ibuprofen or a combination of ibuprofen and acetaminophen in a randomized, double-blind, placebo-controlled study. Int Endod J. 2004 Aug;37(8):531-41. doi: 10.1111/j.1365-2591.2004.00836.x.
PubMed 15230906
Elzaki WM, Abubakr NH, Ziada HM, Ibrahim YE. Double-blind Randomized Placebo-controlled Clinical Trial of Efficiency of Nonsteroidal Anti-inflammatory Drugs in the Control of Post-endodontic Pain. J Endod. 2016 Jun;42(6):835-42. doi: 10.1016/j.joen.2016.02.014. Epub 2016 Apr 12.
PubMed 27080115

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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Study at a glance

From the registry record, last updated by the sponsor on 10 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Efficacy of Pain Control Following Root Canal Treatment Using Paracetamol Alone and in Combination With Three Different Non-Steroidal Anti-Inflammatory Analgesics
ClinicalTrials.gov ID: NCT02417337
Acronym / sponsor ID: NSAID / University of Khartoum
Conditions: Pain, Postoperative Pain, Irreversible Pulpitis
Phase: Phase 2
Study type: Interventional
Recruitment status: Completed
Enrolment: 185 participants (actual)
Lead sponsor: University of KhartoumUniversity, hospital or other
Study start: Aug 2012
Primary completion: Aug 2014 (actual)
Study completion: Jan 2015 (actual)
First posted: 15 Apr 2015 (estimated)
Results: Posted 25 Jun 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 5

Arm	Type	Receives
Group I	Active comparator	Drug: Paracetamolparacetamol 1000mg
Group II	Experimental	Drug: Paracetamol, Drug: Ibuprofenibuprofen 600mg + paracetamol 1000mg,
Group III	Experimental	Drug: Paracetamol, Drug: Mefenamic AcidMefenamic acid 500mg + Paracetamol 1000mg
Group IV	Experimental	Drug: Paracetamol, Drug: DiclofenacDiclofenac K 50mg + paracetamol 1000 mg
Group V	Other	Other: PlaceboPlacebo, no medication

Who may qualify

Ages: 18 to 60 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult

Key inclusion criteria (5 listed)

Spontaneous pain moderate to severe on the verbal rating scale (VRS-4), ranging from 4-10 score based on the numerical rating scale (NRS-11).
Adult patients presented for emergency endodontic treatment with a symptomatic maxillary or mandibular tooth (anterior and premolar) with a pulpal diagnosis of Irreversible pulpitis and normal periapex.
Patient choose to have root canal treatment for pain of endodontic origin.
The patient presented with American Society of Anesthesiologists (ASA) I or II medical history (ASA 1963).
The patient had read and thoroughly understood the pain score level sheet

Key exclusion criteria (7 listed)

Patients below 18 years of age;
Analgesic taken within the last 4 hours;
History of allergy to NSAIDs, paracetamol or local anaesthetics;
History of uncontrolled systemic disease [gastrointestinal (GI) disorders, oesophageal reflux, active asthma, decreased hepatic function, haemorrhagic disorders, or poorly controlled diabetes mellitus].
Patients currently taking opioids, monoamine oxidase inhibitors, tricyclic antidepressants, carbamazepine, diuretics, or anticoagulants;

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
ParacetamolAlso: AcetaminophenNSAID	Drug	Group I, Group II, Group III, Group IV
IbuprofenAlso: isobutylphenyl propanoic acidNSAID	Drug	Group II
Mefenamic AcidAlso: FenamateNSAID	Drug	Group III
DiclofenacAlso: VoltarenNSAID	Drug	Group IV
PlaceboAlso: no medicationempty double gelatinous capsules, having similar weight and appearance of the medications	Other	Group V

Primary outcome

Pain Scores Before and After 8 Hours of Treatment Per Group on the VRS-4 Scale
Time frame: 8 hours
Pain was recorded in the verbal rating scale-4 (VRS-4 scale) before and after 8 hours of medication. The VRS-4 Scale has four categories of pain scores: no pain is the minimum (better outcome), slight pain, moderate pain, and severe pain score is the maximum (worse outcome).
Pain Score on Numerical Rating Scale of Pain (NRS-11)
Time frame: 8 hours
(NRS-11) numerical rating scale of pain between 0 (better) and 10 (worse) before and after treatment

1 secondary outcome

Mean of Pain Reduction Stratified by Sex and Jaw Type on Numerical Rating Scale (NRS-11)
Time frame: 8 hours

Results and safety

Results posted to the registry on 25 Jun 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Group I	37	34
Group II	37	33
Group III	37	34
Group IV	37	35
Group V	37	34

Primary outcome: Pain Scores Before and After 8 Hours of Treatment Per Group on the VRS-4 Scale

Time frame: 8 hours. Count of participants. Unit: Participants

Measure	Group I n = 34	Group II n = 33	Group III n = 34	Group IV n = 35	Group V n = 34
Pain Scores before treatment per Group on the VRS-4 Scale: no pain	0	0	0	0	0
Pain Scores before treatment per Group on the VRS-4 Scale: slight pain	0	0	0	0	0
Pain Scores before treatment per Group on the VRS-4 Scale: moderate pain	12	8	7	15	12
Pain Scores before treatment per Group on the VRS-4 Scale: severe pain	22	25	27	20	22
8 hours after treatment per Group on the VRS-4 Scale: no pain	13	23	21	20	14
8 hours after treatment per Group on the VRS-4 Scale: slight pain	8	3	4	10	7
8 hours after treatment per Group on the VRS-4 Scale: moderate pain	4	4	7	1	6
8 hours after treatment per Group on the VRS-4 Scale: severe pain	9	3	2	4	7

Group I: Chi-Square statistic: 1.126, p = 0.771, Chi-squared
Group II: Chi-Square statistic: 4.591, p = 0.204, Chi-squared
Group III: Chi-Square statistic: 0.869, p = 0.833, Chi-squared

Primary outcome: Pain Score on Numerical Rating Scale of Pain (NRS-11)

Time frame: 8 hours. Median (Full Range). Unit: score on a scale

Measure	Group I n = 34	Group II n = 33	Group III n = 34	Group IV n = 35	Group V n = 34
before treatment	8 (0 to 10)	8 (0 to 10)	8 (0 to 10)	8 (0 to 10)	8 (0 to 10)
after treatment	2.25 (0 to 10)	0.17 (0 to 10)	1.0 (0 to 10)	0.5 (0 to 10)	2.82 (0 to 10)

Group I: Median Difference (Final Values): 2.25, p = 0.000, Sign test
Group II: Median Difference (Final Values): 0.17, p = 0.000, Sign test
Group III: Median Difference (Final Values): 1.0, p = 0.000, Sign test

1 secondary outcome is reported in the full results.

Adverse events

Time frame: 2 years. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Group I	0 of 34 (0%)	0 of 34 (0%)	0 of 34
Group II	0 of 33 (0%)	0 of 33 (0%)	0 of 33
Group III	0 of 34 (0%)	0 of 34 (0%)	0 of 34
Group IV	0 of 35 (0%)	0 of 35 (0%)	0 of 35
Group V	0 of 34 (0%)	0 of 34 (0%)	0 of 34

Limitations and caveats (from the sponsor): One limitation was the time frame for the analysis of pain; more information would have been available if there were a 24-hour outcome line

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 10 Aug 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Results publication: PubMed 17437870Owatz CB, Khan AA, Schindler WG, Schwartz SA, Keiser K, Hargreaves KM. The incidence of mechanical allodynia in patients with irreversible pulpitis. J Endod. 2007 May;33(5):552-6. doi: 10.1016/j.joen.2007.01.023. Epub 2007 Mar 6.
Results publication: PubMed 9594474Albashaireh ZS, Alnegrish AS. Postobturation pain after single- and multiple-visit endodontic therapy. A prospective study. J Dent. 1998 Mar;26(3):227-32. doi: 10.1016/s0300-5712(97)00006-7.
Results publication: PubMed 18498882Attar S, Bowles WR, Baisden MK, Hodges JS, McClanahan SB. Evaluation of pretreatment analgesia and endodontic treatment for postoperative endodontic pain. J Endod. 2008 Jun;34(6):652-5. doi: 10.1016/j.joen.2008.02.017. Epub 2008 Apr 2.
Results publication: PubMed 12148679Mehlisch DR. The efficacy of combination analgesic therapy in relieving dental pain. J Am Dent Assoc. 2002 Jul;133(7):861-71. doi: 10.14219/jada.archive.2002.0300.
Results publication: PubMed 10613619Breivik EK, Barkvoll P, Skovlund E. Combining diclofenac with acetaminophen or acetaminophen-codeine after oral surgery: a randomized, double-blind single-dose study. Clin Pharmacol Ther. 1999 Dec;66(6):625-35. doi: 10.1053/cp.1999.v66.103629001.
Results publicationKeiser K, Hargreaves K.Building effective strategies for the management of endodontic pain. Endodontic Topics, Volume 3, Issue 1, pages 93-105, November 2002
Results publication: PubMed 15230906Menhinick KA, Gutmann JL, Regan JD, Taylor SE, Buschang PH. The efficacy of pain control following nonsurgical root canal treatment using ibuprofen or a combination of ibuprofen and acetaminophen in a randomized, double-blind, placebo-controlled study. Int Endod J. 2004 Aug;37(8):531-41. doi: 10.1111/j.1365-2591.2004.00836.x.
Derived from this study: PubMed 27080115Elzaki WM, Abubakr NH, Ziada HM, Ibrahim YE. Double-blind Randomized Placebo-controlled Clinical Trial of Efficiency of Nonsteroidal Anti-inflammatory Drugs in the Control of Post-endodontic Pain. J Endod. 2016 Jun;42(6):835-42. doi: 10.1016/j.joen.2016.02.014. Epub 2016 Apr 12.
Individual participant dataSharing planned: No. Not shared

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Neamat Abubakr, BDS,MDSc,PhD study director

Faculty of Dentistry, University of Khartoum

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Paracetamol, Ibuprofen and Mefenamic Acid in people with Pain and Postoperative Pain, run by University of Khartoum at 1 site in Sudan.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 10 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Sudan. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 25 Jun 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Pain Scores Before and After 8 Hours of Treatment Per Group on the VRS-4 Scale (time frame: 8 hours). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02417337, which also lists 8 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Aug 2026; AzTrials last refreshed its copy on 7 Nov 2026.