Injuring your front teeth is common. One of the most severe injuries occurs when the tooth is knocked totally out of the mouth (avulsed). Often the best option is to replant the tooth as quickly as possible. This is true only for permanent teeth. Once replanted the tooth can heal in one of two ways if managed correctly. Ideally the ligaments around the root repair and the tooth can be expected to last as long as any other tooth, this is known as ‘periodontal healing’. When there is too much damage to the ligaments, healing occurs by bony replacement. Over a number of years, the adjacent bony socket will remodel the tooth (replace the root with bone) leaving the tooth with no root. Once the root is replaced the visible part of the tooth, the crown, will eventually give way and be lost. This is called ‘bony healing’. Bony healing causes significant problems in the medium term for children and treatments for this are the subject of a different Cochrane Review. A missing front tooth or teeth, as a result of not replanting an avulsed tooth, or as a result of bony healing over the medium to long term, can have a major effect on dental and facial ‘good looks’. This can affect the individual’s self-esteem and general social interaction, as well as how others think and see them.
What was the research?
A systematic review to find out which treatment for managing knocked out and replanted permanent front teeth was the most effective.
Who conducted the research?
The research was conducted by a team led by Peter F. Day from Leeds Dental Institute, UK, on behalf of Cochrane Oral Health. Monty Duggal and Hani Nazzal were also on the team.
What evidence was included in the review?
Authors from Cochrane Oral Health carried out this review and the evidence is up to date to 8 March 2018. The review investigated what treatments encourage the tooth to repair by periodontal healing. A total of four studies were included with a total of 183 participants with 257 teeth. One study involved children and young adults, with the other three involving children only. Each study evaluated a different treatment: hyperbaric oxygen, root canal pastes (Ledermix versus Ultracal), removal of the nerve of the tooth (pulp extirpation), and soaking the knocked out tooth in thymosin alpha 1. Each of the interventions aimed to reduce infection or change the inflammatory response or both, at the time of or shortly after the tooth or teeth were replanted.
What did the evidence say?
The evidence currently available is insufficient to draw reliable conclusions regarding the superiority of different interventions for knocked out and replanted permanent front teeth. There is urgent need for further well-designed randomised controlled trials.
How good was the evidence?
We judged the quality of the evidence to be very low due to problems with the design of the studies.
What are the implications for dentists and the general public?
Based on the results of the included studies, there is insufficient evidence to support or refute the effectiveness of different interventions for avulsed and replanted permanent front teeth. The overall quality of existing evidence was very low and therefore great caution should be exercised when generalising the results of the included trials. There is urgent need for further well-designed randomised controlled trials.
Until more evidence becomes available clinicians should continue to base their treatment decisions on current expert-based guidelines in combination with their own clinical experience and the individual circumstances and preferences of their patients or their parent or guardian, or both.
What should researchers look at in the future?
Unfortunately, as can be seen there are very few studies in the human tooth avulsion literature which can meet the requirements for inclusion in a Cochrane Review. Since the original version of this Cochrane Review, only one further study has been published. Therefore future studies in this area should ensure that they are able to be included when this review is updated again.
Conducting research in this area is difficult for a number of reasons:
- the rarity of the injury,
- the different specialities that are providing the different stages of care for patients suffering avulsion injuries,
- the variability of emergency presentation of patients following avulsion injury,
- the failure by patients to present with sufficient speed that a viable periodontal ligament is still present, and
- the ethical problem of obtaining informed consent in an emergency situation.
This list of problems does not mean that good-quality research is impossible for avulsed and replanted teeth. It does, however, require good planning before undertaking a well-designed study. Good-quality studies require the appropriate financial sponsorship to maintain the enthusiasm of centres to recruit and retain enough participants to ensure the study reaches its power calculation and therefore that a valid conclusion can be drawn from it.
Day PF, Duggal M, Nazzal H. Interventions for treating traumatised permanent front teeth: avulsed (knocked out) and replanted. Cochrane Database of Systematic Reviews 2010 , Issue 1 . Art. No.: CD006542. DOI: 10.1002/14651858.CD006542.pub2 .
This post is an extended version of the review’s plain language summary, compiled by Anne Littlewood at the Cochrane Oral Health Editorial Base.