Reproduced with permission of P Day and M Duggal. Interventions for treating traumatized 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. Copyright © 2010 The Cochrane Collaboration. Published by John Wiley and Sons, Ltd.
Background: Dental trauma is common. One of the most severe injuries is when a permanent tooth is knocked completely out (avulsed) of the mouth. In most circumstances the tooth should be replanted as quickly as possible. There is uncertainty on how best to prepare teeth for replantation.
Objectives: To compare the effects of a range of interventions for managing traumatized permanent teeth with avulsion injuries.
Search strategy: The Cochrane Oral Health Group’s Trials Register (to 28th October 2009); CENTRAL (The Cochrane Library 2009, Issue 4); MEDLINE (1950 to October 2009); EMBASE (1980 to October 2009); http://www.clinicaltrials.gov/;www.controlled-trials.com/ and reference lists of articles were searched. There were no language restrictions.
Selection criteria: Only randomized controlled trials (RCTs), that included a minimum follow-up period of 12 months, for interventions for avulsed and replanted permanent teeth were considered.
Data collection and analysis: Two review authors independently extracted data and assessed trial quality and the risk of bias in studies to be included.
Main results: Three studies, involving a total of 162 patients and 231 teeth were identified. Study one (with a high risk of bias) investigated the effect of extra-oral endodontics. This showed no significant difference in radiographic resorption compared with intra-oral endodontics provided at week 1 for teeth avulsed for longer than 60 minutes dry time. Study two (which had a moderate risk of bias) investigated a 10-minute soaking in thymosin alpha 1 prior to replantation and then its further use as a daily gingival injection for the first 7 days. They reported a strong benefit at 48 months (14% with periodontal healing in the control group versus 77% for the experimental group). Study three (with a high risk of bias) investigated a 20-minute soaking with gentamycin sulphate (4 × 107 U/L) for both groups prior to replantation and then the use of hyperbaric oxygen daily in the experimental group for 80 minutes for the first 10 days. They reported a strong benefit at 12 months (43% periodontal healing versus 88% for the experimental group). There was no formal reporting of adverse events.
Authors’ conclusions: The available evidence suggests that extra-oral endodontics is not detrimental for teeth replanted after more than 60 minutes dry time. Studies with moderate/high risk of bias indicate that soaking in thymosin alpha 1 and gentamycin sulphate followed by hyperbaric oxygen may be advantageous. However, they have not previously been reported as interventions for avulsed teeth and need further validation. More evidence with low risk of bias is required and, with the low incidence of avulsed teeth, collaborative multicentre trials are indicated.
Plain language summary: Treatments for managing knocked out and replanted front teeth. Injuring your front teeth during childhood 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 two ways if managed correctly. Ideally the ligament around the root reforms 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 ligament, healing occurs by bony replacement and the tooth is replaced by bone and lost over a few years. 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 upper tooth or teeth, as a result of not replanting an avulsed tooth or as a treatment for bony healing, 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.
This Cochrane review investigated what treatments encourage the tooth to repair by periodontal healing. Three studies were found. The benefits of these treatments require further investigation before specific medicaments can be advised. This is because the studies had weakness in their design which may have influenced the benefits they found. The following general treatment principle can be concluded which reinforces current treatment guidelines: For teeth with little chance of periodontal healing, a root canal treatment can be carried out before the tooth is replanted without further detrimental effects.
Dental trauma is, unfortunately, a relatively common experience in modern societies and tooth avulsion is one of the most severe of such injuries due to the damage to the periodontal ligament, pulp and supporting bone. Strategies for the management of avulsed teeth have evolved over the past 40 years, led by the monumental clinical and experimental studies of Jens Andreasen of Copenhagen, whose contribution to the understanding of dental trauma and its consequences is without parallel. With the accumulated knowledge gained from Jens Andreasen, co-workers and other fine researchers in the field of dental traumatology, guidelines for the management of avulsed teeth have been drawn up by the International Association of Dental Traumatology (IADT) to address the variety of presenting conditions following tooth avulsion. It is generally accepted that immediate replantation provides optimal conditions for periodontal ligament repair, and while pulpal revascularization is always possible in replanted immature teeth, early endodontic treatment in cases with a mature apex is important to control potential inflammatory root resorption.
Immediate replantation is often not possible for a variety of reasons and research has identified several storage media suitable to maintain the viability of the periodontal ligament in the interval between the injury and the clinical management of the replantation. In Australia, milk is the most readily available and practical medium but commercial preparations of other storage media, such as Viaspan, Hanks balanced salt solution and Eagle’s media have been encouraged in sporting clubs and schools. Unfortunately, knowledge of the importance of maintaining an avulsed tooth in a storage medium is not always known, evidenced by the number of avulsed teeth presenting for treatment with extra-oral dry times in excess of 60 minutes.
It is the management of teeth with long extra-oral dry times that has been the subject of the first of the three studies which fulfilled the rigorous requirements of a Cochrane review reported by the present authors, Peter Day and Monty Duggal. Essentially, this randomized prospective study,1 assessed as showing a high risk of bias, involved 20 patients and investigated the difference in tooth mobility and resorption when an avulsed tooth was endodontically treated extra-orally compared to conventional endodontic treatment commenced one week after replantation and completed two weeks later. In both groups, the devitalized periodontal ligament was removed prior to the treatment regimens. The results indicated greater initial tooth mobility in the teeth endodontically treated extra-orally but after 15 days the two groups were the same, where Grade 1 mobility was reported for the duration of the study. This result was surprising as ankylosis with replacement resorption would be the predictable response with such replanted teeth and no mobility would be possible in the longer term. They also reported differences in the incidence of resorption in favour of the extra-orally endodontically treated teeth. The reviewers concluded that extra-oral endodontics is not detrimental for teeth replanted after more than 60 minutes dry time, which is in conformity with generally accepted practice.
The second study selected was assessed as having a moderate risk of bias and also involved extra-oral endodontics prior to replantation.2 Seventy-three patients were treated within 45 minutes of the avulsion injury. The authors did not provide details of any storage between avulsion and the time of arrival at the treatment centre where the teeth were placed in Dulbecco/Voit modified Eagle’s modified minimal essential medium. The avulsed teeth of the two randomly selected patient groups were either replanted following extra-oral endodontic treatment and soaking either in Talpha 1 or normal saline for 10 minutes. In the experimental group, Talpha 1 was also injected daily via the gingival tissues. Talpha 1 (thymosin alpha 1) is a synthetic 28-amino acid peptide primarily directed toward immune response enhancement. Originally developed for the treatment of hepatitis B and C infections, its experimental use in tooth replantation is novel. The results showed the thymosin group demonstrated greater periodontal healing, less ankylosis, less tooth movement and greater survival over the follow-up period of 48 months.
The third study, assessed as having a high risk of bias, investigated the use of hyperbaric oxygen administered daily for 10 days post-replantation.3 The participants received pure oxygen from a mask for 40 minutes, followed by air for 10 minutes and oxygen again for a further 40 minutes. Prior to replantation, teeth from both experimental groups were cleaned with 0.9% saline and then soaked in gentamycin sulphate injection solution. The replanted teeth were fixed by an arch bar which was removed after one to two months. No endodontic treatment was initiated until there was a diagnosis of pulp necrosis. The results indicated that the hyperbaric oxygen group had a lower proportion of teeth with tooth mobility, pulp necrosis and root resorption. The proportions with tooth loss after one year were 1.37% in the hyperbaric oxygen group compared with 18.46% in the control group. At 12 months post-replantation “complete success” was reported for 87.67% of the hyperbaric group compared to 43.08% in the control group.
The reviewers concluded that there may be advantages in soaking avulsed teeth in thymosin alpha as reported in the second study or in gentamycin sulphate followed by hyperbaric oxygen utilized in the third study, but further investigations and validations are required for these novel interventions.
The strict limitations of a Cochrane review invariably result in the exclusion of many fine clinical and experimental studies which do not fulfil the selection criteria as they are not prospective and randomized. This is evidenced in the present report where only three reports could be included from a large range of studies reviewed. While two of the selected works provide interesting and novel approaches which may in time prove of value, the present IADT guidelines for the management of the avulsed tooth and other dental injuries remain as a standard of care for the unfortunate victims of dental trauma.