The effects of antibiotics on toothache caused by inflammation or infection at the root of the tooth in adults

This review, carried out by authors of the Cochrane Oral Health Group, has been produced to assess the effects of antibiotics on pain and swelling in two conditions commonly responsible for causing dental pain when given with or without dental treatment (such as extraction, drainage of a swelling or root canal treatment).


Dental pain is a common problem and can arise when the nerve within a tooth dies due to progressing decay or severe trauma. The tissue around the end of the root then becomes inflamed and this can lead to acute pain, which gets worse on biting. Without treatment, bacteria can infect the dead tooth and cause a dental abscess, which can lead to swelling and spreading infection that may be life threatening.

The recommended treatment of this form of toothache is the removal the dead nerve and associated bacteria. This is usually done by dental extraction or root canal treatment. Antibiotics should only be prescribed when there is severe infection that has spread from the tooth. However, some dentists still routinely prescribe oral antibiotics to people with acute dental conditions that have no signs of spreading infection.

Minimising inappropriate antibiotic prescribing is plays a key role in limiting the development of antibiotic-resistant bacteria. Since dentists prescribe approximately 8% to 10% of all primary care antibiotics in developed countries, dental prescribing may contribute to antibiotic resistance. Therefore, it is important that antibiotics should only be used when they are clinically beneficial for the person.

Study characteristics

The evidence on which this review is based was up to date as of 1 October 2013. We searched scientific databases and found two trials, with a 62 participants included in the analysis. Both trials were conducted at university dental schools in the USA and evaluated the use of oral antibiotics in the reduction of pain and swelling reported by adults after having the first stage of root canal treatment under local anaesthetic. The antibiotic used in both trials was penicillin VK and all participants also received painkillers.

Key results

The two studies included in the review reported that there were no clear differences in the pain or swelling reported by participants who received oral antibiotics compared with a placebo (a dummy treatment) when provided in conjunction with the first stage of root canal treatment and painkillers, but the studies were small and we could not exclude potentially important differences between groups. Neither study examined the effect of antibiotics delivered by themselves, without dental treatment.

One trial reported side effects among participants: one person who received the placebo medication had diarrhoea and one person who received antibiotics experienced tiredness and reduced energy after their operation.

Quality of evidence

We judged the quality of evidence to be very low. There is currently insufficient evidence to be able to determine the effects of antibiotics in these conditions.

Authors' conclusions: 

There is very low quality evidence that is insufficient to determine the effects of systemic antibiotics on adults with symptomatic apical periodontitis or acute apical abscess.

Read the full abstract...

Dental pain can have a considerable detrimental effect on an individual's quality of life. Symptomatic apical periodontitis and acute apical abscess are common causes of dental pain and arise from an inflamed or necrotic dental pulp, or infection of the pulpless root canal system. Clinical guidelines recommend that the first-line treatment for teeth with symptomatic apical periodontitis or an acute apical abscess should be removal of the source of inflammation or infection by local, operative measures, and that systemic antibiotics are currently only recommended for situations where there is evidence of spreading infection (cellulitis, lymph node involvement, diffuse swelling) or systemic involvement (fever, malaise). Despite this, there is evidence that dentists continue to prescribe antibiotics for these conditions. There is concern that this could contribute to the development of antibiotic-resistant bacterial colonies both within the individual and within the community as a whole.


To evaluate the effects of systemic antibiotics provided with or without surgical intervention (such as extraction, incision and drainage of a swelling or endodontic treatment), with or without analgesics, for symptomatic apical periodontitis or acute apical abscess in adults.

Search strategy: 

We searched the following electronic databases: Cochrane Oral Health Group's Trials Register (to 1 October 2013); Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 9); MEDLINE via OVID (1946 to 1 October 2013); EMBASE via OVID (1980 to 1 October 2013) and CINAHL via EBSCO (1980 to 1 October 2013). We searched the World Health Organization (WHO) International Trials Registry Platform and the US National Institutes of Health Trials Registry ( on 1 October 2013 to identify ongoing trials. We searched for grey literature using OpenGrey (to 1 October 2013) and ZETOC Conference Proceedings (1993 to 1 October 2013). We placed no restrictions on the language or date of publication when searching the electronic databases.

Selection criteria: 

Randomised controlled trials of systemic antibiotics in adults with a clinical diagnosis of symptomatic apical periodontitis or acute apical abscess, with or without surgical intervention (considered in this situation to be extraction, incision and drainage or endodontic treatment) and with or without analgesics.

Data collection and analysis: 

Two review authors screened the results of the searches against inclusion criteria, extracted data and assessed risk of bias independently and in duplicate. We calculated mean differences (MD) (standardised mean difference (SMD) when different scales were reported) and 95% confidence intervals (CI) for continuous data and, where results were meta-analysed, we used a fixed-effect model as there were fewer than four studies. We contacted study authors to obtain missing information.

Main results: 

We included two trials in this review, with 62 participants included in the analyses. Both trials were conducted in university dental schools in the USA and compared the effects of oral penicillin V potassium (penicillin VK) versus a matched placebo given in conjunction with a surgical intervention (total or partial pulpectomy) and analgesics to adults with acute apical abscess or symptomatic necrotic tooth (no signs of spreading infection or systemic involvement (fever, malaise)). We assessed one study as having a high risk of bias and the other study as having unclear risk of bias.

The primary outcome variables presented were participant-reported pain and swelling (one trial also reported participant-reported percussion pain). One study reported the type and number of analgesics taken by participants. One study recorded the incidence of postoperative endodontic flare-ups (people who returned with symptoms that necessitated further treatment). Adverse effects as reported in one study were diarrhoea (one participant, placebo group) and fatigue and reduced energy postoperatively (one participant, antibiotic group). No studies reporting quality of life measurements were suitable for inclusion.

Objective 1: systemic antibiotics versus placebo with surgical intervention and analgesics for symptomatic apical periodontitis or acute apical abscess.
Two studies provided data for the comparison between systemic antibiotics (penicillin VK) and a matched placebo for adults with acute apical abscess or a symptomatic necrotic tooth. Participants in one study all underwent a total pulpectomy of the affected tooth while participants in the other study had their tooth treated by either partial or total pulpectomy. Participants in both trials received oral analgesics. There were no statistically significant differences in participant-reported measures of pain or swelling at any of the time points assessed within the review. The MD for pain (short ordinal numerical scale 0 to 3) was -0.03 (95% CI -0.53 to 0.47) at 24 hours; 0.32 (95% CI -0.22 to 0.86) at 48 hours and 0.08 (95% CI -0.38 to 0.54) at 72 hours. The SMD for swelling was 0.27 (95% CI -0.23 to 0.78) at 24 hours; 0.04 (95% CI -0.47 to 0.55) at 48 hours and 0.02 (95% CI -0.49 to 0.52) at 72 hours. The body of evidence was assessed as at very low quality.

Objective 2: systemic antibiotics without surgical intervention for adults with symptomatic apical periodontitis or acute apical abscess.
We found no studies that compared the effects of systemic antibiotics with a matched placebo delivered without a surgical intervention for symptomatic apical periodontitis or acute apical abscess in adults.