New Dental Trauma Guidelines for Permanent Teeth: A Perspective

Severe dental injuries—luxations, fractures and avulsions—are rare and unexpected. Consequently, a dentist confronted with such an injury will need accessible guidelines. In 2011, the International Association of Dental Traumatology (IADT) revised its trauma management guidelines that were previously published in 2007. A number of changes to the guidelines for permanent teeth will affect both treatment and medicolegal aspects of practice. The guidelines are available on the IADT website.^1-3 A link is also included to the Dental Trauma Guide,⁴ that provides extensive diagnostic and treatment information, matched to the IADT trauma guidelines.

What is New or Different?

Many of the changes to the 2007 version of the guidelines affect all serious injuries, but by far the greatest emphasis was on avulsion.

Clinician Discretion Emphasized in Radiographic Examination

Radiographic examination was previously specified to ensure that a minimum number of views were taken. However, efforts to reduce radiation exposure increasingly place the onus on the clinician to take the appropriate number and type of views. Diagnostic-quality radiographs are expected, although sometimes difficult to obtain in injured pre-adolescents and youth, as radiographs are important for both diagnosis and treatment planning. In addition, dental injuries often involve third-party assessors, who may request objective documentation of the injury.

Systemic Antibiotic Coverage Not Always Advantageous

Routine antibiotic coverage must be weighed against the risk of unnecessary exposure. Currently, there is no evidence to support positive effects of systemic antibiotics on the outcomes of replantation. Pediatricians and pediatric dentists are increasingly concerned about unnecessary exposure to antibiotics, and the clinician’s decision should be based on the individual case and consider specific medical conditions.

Splint Type and Duration of Use Clarified

Splint type and duration of use vary according to the outcome sought. If periodontal ligament (PDL) regeneration is the expected outcome, then light wire splints for a short duration (up to 2 weeks) are recommended. If ankylosis and root resorption is the expected outcome, then the duration is increased to 4 weeks and the rigidity is less important. If a root is fractured and secondary healing is the expected outcome, then the duration and rigidity of splinting are similar to that when ankylosis is expected.

At the Hospital for Sick Children (SickKids), we use a composite resin, orthodontic wire splint or a titanium trauma splint.

Ongoing Pulp Vitality Assessment Needed

This revision clarifies the fact that, at the time of injury, cold and electric pulp testing may give unreliable responses. Follow-up is required to make the diagnosis of non-vital pulp and at least 2 signs or symptoms are required to confirm pulp necrosis.

We begin pulp testing some weeks or months after the injury or immediately on appearance of radiographic or clinical evidence of pain or swelling

Avulsed Teeth Will Never Be the Same, Regardless of Treatment

This is the first time the avulsion guideline reflects the results of a number of papers that show that the outcome of delayed (> 5 minutes) replantation is eventual tooth loss. This has been confusing, because replanted teeth in fully grown adults may function for decades. However, over the past 20 years, research has clarified the difference between replantation in the 7–16 year group (most likely to have avulsed teeth) and those who have achieved full facial growth (young adults and adults). Extraction within 5 years is the norm for pre-adolescent children. This may be due to root resorption or the limiting effects of ankylosed incisors on orthodontic treatment. The guidelines now state, “…it is important to realize that some of the replanted teeth have lower chances of long-term survival and may even be lost or extracted at a later stage.”

Not All Teeth Should Be Replanted

The revision is the first guideline to emphasize that not all teeth should be replanted. Reasons include severe caries or periodontal disease, non-cooperative patient, severe medical conditions, such as immunosuppression, and severe cardiac disease. Other factors that were not mentioned are unfavourable crown–root ratio, severe malocclusion in a pre-adolescent, extensive comminution of alveolar bone or failure to obtain parent or guardian consent. Once again, it is stated in the guideline that primary teeth should not be replanted.

Pre-replantation Root Treatments Not Compulsory

Topical antibiotics and sodium fluoride soaks continue to be recommended to facilitate pulp revascularization and periodontal healing, but this revision makes it clear that support for these practices is experimental and based solely on animal or in vitro studies. This change in emphasis frees clinicians who do not have access to minocycline, doxycycline or 2% sodium fluoride solution from the implication that failure to provide this treatment is below the expected standard of care. This revision states that root soaking in fluoride “should not be seen as an absolute recommendation.”

Unresolved Issues

Extra-alveolar Duration and Periodontal Ligament Regeneration

Although avulsions represent only a small proportion of dental injuries, avulsion–replantation issues were the focus of the most attention in this revision. Healing of a replanted tooth can only occur by repair or PDL regeneration. In the first case, the outcome is ankylosis and root resorption with infra-occlusion of the tooth, if the patient has not completed his or her adolescent growth spurt, and later extraction of the tooth. In the second case, the outcome is a tooth with some areas of damage, but a largely functional PDL and normal survival.

The avulsion guideline continues to base treatment on root maturity (incomplete or complete root formation) and the state of the PDL adherent to the root. The avulsion task group defined replantation within 5 minutes as immediate and from 60 minutes onward as non-viable (necrotic PDL). In the period between 5 and 60 minutes, root-surface PDL cells are viable but compromised.

If a tooth is replanted at the accident site, subsequent treatment is splinting. If root formation is incomplete, the clinician can elect to monitor for possible pulp revascularization beyond 10 days. Otherwise, root canal treatment should be initiated within 10 days and before splint removal.

A dentist may replant teeth between 5 and 60 minutes after avulsion (subject to the cautions described) followed by root canal treatment within 10 days for mature roots or observation for pulp revascularization in immature roots. If extraoral duration is longer than 60 minutes, the tooth receives root canal treatment and splinting regardless of root maturity.

The 2007 and 2011 guidelines both note that immediate extraoral root canal treatment before replantation is an alternative to waiting up to 10 days. The goal is to prevent inflammatory resorption, and human outcome studies have shown this technique to be effective.

Root Maturity and Pulp Vitality

The 2011 guideline now cautions, “The risk of infection-related [inflammatory] root resorption should be weighed up against the chances of revascularization. Such resorption is very rapid in teeth of children. If revascularization does not occur, root canal treatment may be recommended.” This risk of rapid root resorption and patient discomfort is the reason we do immediate extraoral root canal treatment before replantation in the pediatric population at SickKids.

Variance with IADT Guidelines at SickKids

Two types of healing are observed in avulsion injuries: regeneration and root resorption. Regeneration occurs in cases of immediate replantation (< 5 minutes). Inflammatory resorption can be controlled by root canal treatment (immediate or within 10 days), but replacement resorption persists. Based on our research and that of others, we complete root canal treatment and removal of necrotic PDL before we replant any tooth when extraoral duration is extended (> 5 minutes). Removal of necrotic PDL is consistent with the principles of wound healing. Periodically, a caregiver or a dentist will replant a tooth before sending a patient directly to our clinic. If extraoral duration before replantation is extended, we offer 2 choices: we can splint the tooth and complete the root canal treatment in stages; or remove the tooth and complete root canal treatment and removal of necrotic PDL before replanting and splinting. The outcome will not change, but intraoral root canal treatment and some clinic visits will be avoided. Our procedures can be found on the hospital’s website.⁵

Dealing with Unknowns — Future Research Needed

We believe that the most important issue is the critical extraoral duration before root surface stem cells in the PDL lose their ability to reproduce, differentiate into fibroblasts and produce functional PDL (regeneration). Simply proving PDL cell vitality does not guarantee regeneration of PDL. There seems to be agreement on removing necrotic PDL tissue from the root side, but the ideal method has not been determined. We have shown that almost half the PDL is torn from a tooth at the time of avulsion. Denuded areas become sites of ankylosis and resorption, but there is no evidence for or against leaving necrotic PDL on a replanted tooth.

Before replantation, parents are informed that it will be a temporary measure designed to restore normalcy, one of their main wishes. This provides time to arrange an orthodontic consultation and for the growing child to come to terms with the eventual loss (extraction) of the tooth or teeth.

THE AUTHOR

Dr. Kenny is an honorary consultant, department of dentistry, The Hospital for Sick Children, and professor of dentistry, University of Toronto. He was a director of IADT and a task group member at the time of the 2011 revision. He is now associate editor, section on pediatrics and orthodontics of the journal, Dental Traumatology, and a member of the Dental Trauma Research Unit of The Hospital for Sick Children, Toronto.

The author has no declared financial interests.

This article has been peer reviewed.