Are antibiotics an effective way to prevent infection following tooth removal?

Teeth that are affected by decay or gum disease or painful wisdom teeth are often removed by dentists. Tooth extraction is a surgical procedure that leaves a wound in the mouth that can become infected. Infection can lead to swelling, pain, development of pus, fever, as well as ‘dry socket’. Dry socket is where the tooth socket is not filled by a blood clot, and there is severe pain and bad odour. These complications are unpleasant for patients and may cause difficulty with chewing, speaking, and teeth cleaning, and may even result in days off work or study. Treatment of infection is generally simple and involves drainage of the infection from the wound and patients receiving antibiotics.

Antibiotics work by killing the bacteria that cause infections, or by slowing their growth. However, some infections clear up by themselves. Taking antibiotics unnecessarily may stop them working effectively in future. This ‘antimicrobial resistance’ is a growing problem throughout the world. Antibiotics may also cause unwanted effects such as diarrhoea and nausea. Some patients may be allergic to antibiotics, and antibiotics may not mix well with other medicines. Dentists frequently give patients antibiotics at the time of the extraction as a precaution in order to prevent infection occurring in the first place. This may be unnecessary and may lead to unwanted effects.

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Do the drugs work? Cochrane evidence on antibiotics in dentistry

799px-Medication_amoxycillin_capsule13-17 November is World Antibiotic Awareness Week. The World Health Organization (WHO) has said that antibiotic resistance is:  “one of the biggest threats to global health, food security, and development today”. Antibiotics are used to prevent and treat bacterial infections, but if over-used they can cause bacteria to change and become resistant. This makes infections more difficult to treat, and results in longer hospital stays, higher medical costs and increased mortality (World Health Organization, 2017).

Antibiotics are still commonly used in dentistry, Cope et al (2014) estimate that 8-10% of antibiotics used in primary care are prescribed by dentists in some parts of the world. Their effectiveness has been explored by several Cochrane Oral Health reviews over the years, looking at some of the scenarios where they might be prescribed. Today we have a look back over the evidence… Continue reading

Should asymptomatic disease-free impacted wisdom teeth be removed? Insufficient evidence!

Tooth extraction concept with an array of stainless steel dental tools and a mask with the extracted tooth clasped in the pincers and reflected in the mirrorWisdom teeth, or third molars, generally erupt between the ages of 17 and 26 years. These are the last teeth to erupt, and they normally erupt into a position closely behind the last standing teeth (second molars). Space for these teeth to erupt can be limited. Wisdom teeth often fail to erupt or erupt only partially, which is often due to impaction of the wisdom teeth against the second molars (teeth directly in front of the wisdom teeth). In most cases, this occurs when second molars are blocking the path of eruption of third molar teeth and act as a physical barrier, preventing complete eruption. An impacted wisdom tooth is called asymptomatic and disease-free in the absence of signs and symptoms of disease affecting the wisdom tooth or nearby structures.

Impacted wisdom teeth can cause swelling and ulceration of the gums around the wisdom teeth, damage to the roots of second molars, decay in second molars, gum and bone disease around second molars and development of cysts or tumours. General agreement exists that removal of wisdom teeth is appropriate if signs or symptoms of disease related to the wisdom teeth are present. Less agreement exists about the appropriate management of asymptomatic disease-free impacted wisdom teeth. Continue reading

No evidence from randomized controlled trials on how to treat bleeding after tooth extraction

Female at the dentistAfter tooth extraction, it is normal for the area to bleed and then clot, generally within a few minutes. It is abnormal if bleeding continues without clot formation, or lasts beyond 8 to 12 hours; this is known as post-extraction bleeding (PEB). Such bleeding incidents can cause distress for patients, who might need emergency dental consultations and interventions. The causes of PEB can be local, a systemic disease, or a medication. To control this bleeding, many local and systemic methods have been practised, based on the clinician’s expertise. To inform clinicians about the best treatment, evidence is needed from studies where people have been randomly allocated to one of at least two different groups, which receive different treatments, or no treatment (i.e. ‘randomised controlled trials’ or RCTs). Continue reading

Surgical techniques for removing wisdom teeth

Mandibular wisdom toothThis research assesses the benefits and harms of the different ways to surgically remove wisdom teeth from the lower jaw. Removing wisdom teeth is one of the most common operations in dental surgery. Various techniques have been developed to carry this out, but which is the most effective? The review considered the following risks from surgery: pain after treatment, swelling, infection, the ability to open the jaw fully, damage to the nerves supplying sensation to the tongue and jaw fractures. Continue reading

Review of the Month: do antibiotics cause more harm than good?

AntibioticsDentists often have to remove teeth which are affected by decay or gum disease. They also remove wisdom teeth that are poorly aligned or underdeveloped. The risk of infection after extracting wisdom teeth is around 10%, but can be as high as 25% in patients who are already sick. Swelling, pain, fever and dry socket are common complications.

But should dentists try to protect patients from infection by giving them antibiotics just before or just after surgery? Or are the side effects of the antibiotics worse than the infection? There has been concern that too much exposure to antibiotics is a risk to health, as the body becomes less able to fight off infections. What’s the evidence on the use of antibiotics to prevent complications after tooth extraction? Our highlighted Review of the Month for August considers the issues.

What was the research?

A systematic review of the evidence to find out whether taking antibiotics is an effective way to prevent infections after tooth extraction.

Who conducted the research?

The research was conducted by a team led by Giovanni Lodi from the Universita degli Studi di Milano, on behalf of the Cochrane Oral Health Group. Lara Figini, Andrea Sardella, Antonio Carrassi, Massimo Del Fabbro and Susan Furness were also on the team.

What evidence was included in the review?

Data was extracted from 18 randomised controlled trials. A total of 2,456 people having teeth extracted participated in the trials, and were randomly assigned to antibiotics or placebo.

What did the evidence say?

There is evidence that antibiotics reduce the risk of infection by approximately 70%. There is also evidence that people who take antibiotics have less pain a week after the extraction compared with those who do not. However, using antibiotics caused more generally brief and minor side effects for these patients. There was no evidence of a difference between antibiotics and placebo in reduction of fever or swelling.

The review found that approximately 12 people would need to receive antibiotics in this way to prevent one infection, and 38 people would need to be treated with antibiotics to prevent one case of dry socket

The review concludes that antibiotics given to healthy people to prevent infection may cause more harm than benefit to both the individual patients and the population as a whole. There were no trials which looked at antibiotics to prevent infections in people with severely decayed teeth, or those who were sick or had low immunity. It is possible that antibiotics may be more beneficial for these patients.

How good was the evidence?

13 trials were at high risk of bias, and the risk of bias for the other five trials was not clear due to poor reporting of the methods and results. The quality of the evidence was generally moderate for most of the outcomes that were under study.

What are the implications for dentists and the general public?

There is moderate quality evidence that use of antibiotics as a prophylaxis, given to prevent infection, reduces the risk of infection in patients undergoing tooth extraction. There is no clear evidence that the timing of when the drugs are given (just before or just after surgery) is important. The size of the benefit is not enough to recommend routine use of antibiotics, due to the increased risk of mild side effects and the potential for developing resistance to antibiotics.

What should researchers look at in the future?

Future randomized controlled trials should look at whether infection can be prevented by use of antibiotics in patients at high risk of complications, such as people with low immunity. Trials on patients undergoing extractions for severe tooth decay are also needed.


Lodi G, Figini L, Sardella A, Carrassi A, Del Fabbro M, Furness S. Antibiotics to prevent complications following tooth extractions. Cochrane Database of Systematic Reviews 2012, Issue 11. Art. No.: CD003811. DOI: 10.1002/14651858.CD003811.pub2.

New edition of the Cochrane Library is out today!

A new edition of the Cochrane Library has been published, and features one new review and 5 new protocols from the Oral Health Group, a bumper month!

New review: AntibioticsImage to prevent complications following tooth extraction
Giovanni Lodi, Lara Figini, Andrea Sardella, Antonio Carrassi, Massimo Del Fabbro, Susan Furness

This review looks at whether antibiotics, given to dental patients as part of their treatment, prevent infection after tooth extraction. There were 18 studies considered, with a total of 2456 participants who received either antibiotics (of different kinds and dosages) or placebo, immediately before and/or just after tooth extraction. Do they do more harm than good? Follow the link to read more!

New Protocol: Clinical assessment to screen for the detection of oral cavity cancer and potentially malignant disorders in apparently healthy adults
Tanya Walsh, Joseph LY Liu, Paul Brocklehurst, Mark Lingen, Alexander R Kerr, Graham Ogden, Saman ImageWarnakulasuriya, Crispian Scully

This is a protocol for the Oral Health Group’s first review of diagnostic test accuracy, a new area of research for the Group. The objective of this review is to estimate the accuracy of the conventional oral examination (COE) used singly or in combination with another index test as a screening test for the detection of oral cancer and potentially malignant disorders (PMD) of the lip and oral cavity of apparently healthy adults.

New Protocol: Interventions for replacing missing teeth: alveolar ridge preservation techniques for oral implant site development
Momen A Atieh, Nabeel HM Alsabeeha, Alan GT Payne, Warwick Duncan, Marco Esposito

A protocol for a new review. The aim is to assess the clinical effects of various materials and techniques for alveolar ridge preservation (ARP) after tooth extraction compared with extraction alone and/or other methods of ARP for patients requiring oral implant placement following healing of extraction socket.

ImageNew Protocol:Lasers for caries removal in deciduous and permanent teeth
Alessandro Montedori, Iosief Abraha, Massimiliano Orso, Potito Giuseppe D’Errico, Stefano Pagano, Guido Lombardo

This protocol is for a new review which will compare the effects of laser-based methods to conventional mechanical methods for the removal of dental caries in deciduous and permanent teeth.

New Protocol: Maternal consumption of xylitol for preventing dental decay in children
Derek Richards, Brett Duane, Andrea Sherriff

Protocol for a new review. The aim is to evaluate the effects of xylitol (consumed by mothers) at reducing tooth decay in their children compared with alternative treatments (e.g. chlorhexidine, fluoride varnish, placebo, or no treatment).

New Protocol: Orthodontic treatment for bimaxillary proclination in children and adults
Padhraig S Fleming, Nikolaos Pandis, Zbys Fedorowicz, Reshma A Carlo, Jadbinder Seehra

This new protocol is for a Cochrane review which will assess the effects of different types of orthodontic treatment for bimaxillary proclination particularly their impact on occlusal results, facial outcomes and patient experiences.

Other highlights of the Cochrane Library, Issue 11, 2012:

There is also an editorial on Measuring the Performance of the Cochrane Library.