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This article describes the immediate and definitive options for treating a child or young person presenting with a fractured permanent incisor. Furthermore, it considers three common clinical problems that dentists may encounter when restoring these teeth, and provides advice on how to overcome these difficulties. This article also aims to increase the reader's awareness of the importance of providing an optimal restoration for young patients, and the potential short- and long-term consequences of failing restorations.
CPD/Clinical Relevance: This article aims to guide the reader through the recommended techniques for restoring fractured permanent incisors in young patients and demonstrate how to manage common clinical challenges, while highlighting the importance of providing an optimal restoration.
Article
In dental practice, the presentation of a child with a crown fracture is a regular occurrence, with the incidence of traumatic dental injuries peaking around the ages of 7–12, with males more likely to suffer a traumatic injury than their female counterparts.1,2,3,4 While a crown fracture alone is not the most severe dental injury, it is one of the most common, accounting for 26–76% of injuries to permanent teeth.5
The prognosis of a tooth with a crown fracture is dependent on a number of factors, including:
The stage of root development at the time of injury;6,7,8
Concomitant injuries to the periodontal ligament (eg luxation injuries);6-8
The clinical consequences of a crown fracture include: development of pulpal necrosis, resorption, infection and loss of tooth. Concomitant injury to the periodontal ligament results in a disruption to pulpal circulation, reducing healing capacity. It also provides bacteria with access to pulpal tissue, increasing the risk of inflammation and subsequent pulpal death.8
In the absence of concurrent injuries, the potential for development of pulpal necrosis is greatest in teeth with complicated crown fractures, and fractures extending sub-gingivally. These injuries carry increased risk of bacterial ingress due to difficulty in providing adequate dentinal and/or pulpal seal.11,12 It is important that traumatic injuries to the teeth are diagnosed correctly in order to provide effective and correct treatment, particularly in recognizing any adjunctive ‘movement’ injury that will have damaged the ligament tissues and is likely to require stabilization.5
The risk of pulpal death is also potentially higher in children where there is delayed treatment,9 or cooperation is not sufficient to provide emergency care, as this leaves dentine exposed, which may result in bacterial contamination of the pulpal tissues.
The dentine–pulp complex is capable of initiating a healing response, as evidenced by the work of Rodd and Boissonade using immunocytochemical analysis.13 This study showed that the number of leukocytes (a white blood cell which plays an important role in fighting microbes) present in the pulpal tissues increases in the presence of inflammation. This change was observed in both primary and permanent teeth.
None the less, prolonged exposure of the dentinal tubules to the bacteria-dense oral cavity will pose too great a burden for the pulpal immune response pathway, and pulpal necrosis will commence. As such, the need for both immediate and sustained dentine protection is paramount. This is particularly important in children and young people who may struggle to cope with endodontic treatment. It is also essential that primary care clinicians are confident in managing these patients, as they are most likely to present to a primary care setting following initial injury.
The aim of this paper is to discuss the management options for uncomplicated crown fractures. This paper does not detail the management of the exposed, infected or necrotic pulp. Further information on this can be found in the International Association of Dental Traumatology Guidelines.14
Immediate dentine seal
It has been observed that ‘significant pulp inflammation’ can only occur in the presence of bacteria, therefore the aim of the emergency treatment phase is to prevent the ingress of bacteria.15 In the event of an enamel–dentine fracture, the patient will have exposed dental tubules. It is essential that these are sealed as soon as possible. The two mainstay materials for provision of an immediate ‘bandage’ are glass ionomer cement and composite resin. The choice between the two is largely dependent on the patient's ability to cope with treatment, as well as the presence and severity of concurrent dental injuries, and the time available at the emergency appointment.
The patient requiring repositioning of a tooth, placement of a splint, or pulp therapy will undoubtedly require administration of local anaesthetic. This will facilitate painless etching of exposed dentine, allowing composite to be placed. If a rubber dam is applied for prior pulp therapy, this will provide optimal moisture control for the composite restoration, so that the definitive composite restoration could be placed at this time if patient cooperation allows. Unfortunately, due to factors such as age, soft tissue discomfort, anxiety and distress, both at the time of injury and in the immediate aftermath, some children and young people are unable to tolerate the use of local anaesthetic. In this instance, a suitable alternative may be to use a self-etching bonding agent such as Adper Prompt L-pop (ESPE, Seefeld, Germany) to adhere a composite or compomer restoration, providing a temporary dentinal seal until the patient is able to accept further treatment. The bonding strength of L-pop has been shown to be inferior to conventional bonding methods, so it is preferable to use conventional etch and bond techniques where possible for definitive restorations.16,17 The bandage itself should seal the enamel and dentine, overlapping onto the labial and palatal surface to maximize the surface area for bonding.
Should the fractured portion of tooth be retained, and in one single piece, this can be reattached, either as an interim or definitive restoration (Figures 1–3). The benefits of using the original tooth fragment include a shorter treatment time, immediate hermetic seal and the achievement of good aesthetics and function, maintaining the original tooth shade, translucency and shape.18 It is less technically challenging for the operator, with less clinical time required and, therefore, potentially easier for patients to accept treatment. It could be emotionally beneficial to the patient as the tooth form is restored immediately. The recommended technique is as follows:
Isolate the injured tooth with use of rubber dam, where possible;
Ensure the tooth fragment and bonding surface is clean from debris by polishing with pumice;
Prepare the fragment and the tooth with phosphoric acid etchant;
Use of a flowable or microfine composite is recommended to reseat the fragment;
Cut buccal and palatal chamfers and restore with composite to improve strength and conceal joins.18
Figure 1. Enamel–dentine fracture affecting the upper right central incisor.Figure 2. Retained tooth fragment.Figure 3. Restoration placed using the retained tooth fragment and composite.
There may be situations, however, in which reattachment of the original fragment is not appropriate, including a concomitant luxation injury (where a dry operating field may not be possible), a pre-cooperative patient, or a patient who is too distressed at the time of the injury to allow the procedure.
If the crown fracture extends sub-gingivally, glass ionomer cement should be placed as a temporary seal and the patient referred to specialist services for definitive restoration. There will be local guidelines regarding completion of this referral, but it is the opinion of the authors that this referral should be made urgently by telephone, with a letter to follow, to minimize possible negative outcomes for the patient. The treatment options available for sub-gingival uncomplicated fractures are discussed later in this article.
Definitive restoration
The definitive restoration should be placed as soon as reasonably possible to provide a more durable seal for the dentine, to restore the aesthetics and prevent tooth movement. The 2003 Child Dental Health Survey reported that 82% of 8-year-olds and 73% of 15-year-olds had untreated traumatized incisors.19
The aesthetic component is particularly important for children and young people, as those who have experienced dental trauma are often subject to unkind remarks at school.20 Additionally, tooth movement in children and young people can occur rapidly, resulting in a loss of space available for the definitive restoration, and hence complicating treatment further.
Failure of ‘definitive’ composite restorations is common, with many young patients describing their ‘fillings’ falling off and requiring replacement on multiple occasions. The literature suggests that fracture of the restoration, staining, shade or marginal mismatches and poor adhesion are the main causes of failure of anterior composites.21 This could be due to difficulties with moisture control at the time of placement (either due to gingival bleeding or inability to accept rubber dam) or patient behaviour. Unfortunately, this can have significant impacts on the patient, including:
Multiple visits to the dentist, and hence time off school;
The potential for teasing/refusal to attend school;
Anxiety that future restorations may also be lost;
Space loss and the potential requirement for corrective orthodontic treatment;
Decreased cooperation.
Furthermore, the loss of the restoration also renders the dentine–pulp complex vulnerable to bacterial ingress. If the tooth is already undergoing endodontic treatment, loss of the restoration can result in loss of working length reference point, and loss of the coronal seal.
It is preferable to give local anaesthetic whenever possible, as knowing that the child is not going to have any pain results in better quality restorations. However, patients may be anxious and distressed at the thought of an injection. In this situation, local anaesthetic can be avoided, provided that the dentine tubules are not exposed. This can be achieved by simply reducing an immediate bandage, rather than removing it entirely. Moreover, use of alternative rubber dam placement techniques, such as floss ligatures or wedjets, can be considered in lieu of a clamp to prevent the need for soft tissue anaesthesia.
Below we consider some of the common challenges in providing a definitive restoration for fractured incisors in children.
The problem: lack of tooth tissue
Lack of tooth tissue can make restoration of the fractured maxillary incisor difficult, and time consuming. In addition to good isolation and use of a large surface area for bonding, the use of crown formers provides an excellent aesthetic result in minimal time (Figures 4–8). The crown former can be adjusted to the tooth as required, and enables maximum use of available surface area by wrapping the composite around the tooth at the base of the restoration.
Figure 4. The fractured upper right central incisor prior to restoration.Figure 5. The incisal edge of the contralateral incisor is used to determine the size of crown former to be used.Figure 6. The trimmed crown former is tried onto the fractured incisor.Figure 7. Once the composite has been cured, the crown former can be removed with a straight probe, or a spoon excavator.Figure 8. The final restoration following polishing.
The correct size is usually identified by measuring or comparing the width of the contralateral incisor (assuming it is uninjured) as seen in Figure 5. Once the crown former has been chosen and adjusted, the placement is simple and can be completed quickly and easily, even in children who have difficulty sitting still throughout treatment. The composite is cured as per manufacturer's instructions, and on removal of the crown former (Figure 7), the restoration requires minimal adjustment or polishing, if any.
If the tooth in question has already lost vitality and undergone endodontic treatment, an alternative would be the addition of an immediate fibre post and composite crown using the technique above.
A fibre post system, such as the RelyX Fiber Post (3M, St Paul, USA) gives the additional benefit of greater retention of the restoration and can be placed immediately after completion of root canal obturation. The fibre post is translucent, with no visibility of post through the definitive restoration. This post system is not radio-opaque, and is not visible radiographically, so it is important to explain this to the patient and his/her parent as another clinician viewing the radiograph may presume that there is a deficient root canal obturation present. This could potentially lead to unnecessary accessing of the tooth at a later stage.
In the instance where a composite restoration has been attempted using the aforementioned technique, yet has subsequently failed, referral to specialist services is appropriate.
The problem: sub-gingival fracture
The restorability of a tooth with a sub-gingival fracture (Figure 9) must be determined through identification of the base of fracture, and identification of how it can be accessed to provide a well-bonded restoration.
Figure 9. The fracture on the mesio-palatal aspect of the upper left central incisor can be seen to extend sub-gingivally.
An initial step may be to use retraction cord to visualize the fracture base where possible. This will require use of local anaesthetic, and therefore good compliance from the patient. Electrocautery may be used by suitably experienced practitioners to expose the base of the fracture in non-aesthetic areas (such as the palatal margin/interproximal gingivae), and to provide coagulation.
Once the tooth has been adequately restored, it should be ensured that no sub-gingival ledges of restorative material persist. The periapical radiograph in Figure 10 shows a ledge present sub-gingivally, which was not visible clinically and, if not corrected, this would have had implications for gingival health.
Figure 10. The same central incisor with a composite ledge following a sub-gingival restoration.
Where visualization of the fracture base is not possible, for example the fracture extends below the level of alveolar bone, consideration must be given to extrusion (either with orthodontics or surgery) to facilitate restoration. Orthodontic or surgical extrusion requires both good communication and a relationship with the appropriate team to ensure that the treatment is planned and completed without error or delays. Decoronation and root burial can also be considered. In the instance of root burial, an appliance (such as an Essix) should be constructed immediately to maintain the space and bone levels for a definitive restoration, preventing spontaneous space migration, and providing the patient with satisfactory aesthetics.18
The problem: loss of space for restoration
Space loss prior to restoration can occur, especially where there has been a delay in seeking treatment, or a delay in seeking remedial treatment after loss of a restoration. In these cases, it is often necessary to consider a simple, short-term removable orthodontic appliance to increase the space available for restoration. This can be provided in general practice by an appropriately trained and experienced practitioner, or can be provided through specialist paediatric or orthodontic services.
Summary
Uncomplicated crown fractures are the most common traumatic dental injury observed in children. It is likely that these children will present in the first instance to a primary care provider. The published literature shows that these teeth are often left untreated, which has negative long-term consequences for children and can affect their function, appearance and confidence.
There can be many issues in providing these children with comfortable, aesthetic, long-term restorations. The authors hope that this paper has shown that, with careful planning and consideration of techniques, including the use of crown formers, these children can often be effectively managed without the need for specialist intervention.
