Management of dental trauma: re-attachment workflows. Guidelines and case studies

Dental trauma presents in a number of different ways. With certain profiles having a higher risk, such as proclination of upper anterior teeth,¹ and a myriad of injury types, industry standards have been developed to bring consistency in the management of such clinical scenarios. The outcome of dental trauma cases is equally varied, and can be dependent on the mode of management at the acute presentation. Pulpal vitality, retention of the periodontal ligament, discolouration factors, apical maturity, mobility and recession are just some of the follow-up complications that can be influenced not only by the nature of the injury, but also the method of immediate management.² Such situations cater for around 33% of adult trauma injuries for which treatment is sought. It is also stated that the majority of such injuries occur before the age of 19.³ Dental trauma might have a severe influence on the social and psychological life of a patient, and so it is critical that restoration of such injuries is carried out using predictable methods.

This article presents two cases of dental trauma where the retained fragments of teeth were used, together with adhesive techniques, to bring a stable solution, but with variation in the aesthetic result. This highlights the relevance of trauma management, the techniques at the disposal of the dental professional and the variation in outcome when trauma is involved.

Aesthetic zone trauma requires the same level of history and assessment as any other type of dental trauma. It is essential that details are recorded in line with consistent and established protocols:

• Time since trauma;
• Location of trauma;
• Nature of trauma;
• Accessory injuries such as intra-/extra-oral soft tissues, nose, eye and face;
• Retention of fractured teeth if at all;
• Method of containment of fragments if at all
• Medical/drug history;
• Social factors;
• General emotional and physical state during injury and at clinical presentation;
• Radiographic examination;
• Sensitivity testing;
• Indications for splinting;
• Need for antibiotics;
• Indications for pulp therapies.

The following cases highlight the use of adhesive techniques and a knowledge of hue, chroma and opacity to re-attach tooth fragments in an aesthetic-zone trauma. The cases also highlight the variance in outcome based on the nature of the trauma and the injury sustained.

Case 1

In Case 1, the patient had had a fall and fractured his upper left central incisor. He also had an accessory injury to the border of the upper lip. The injury was symptomatic only when the tooth was touched, or in the presence of thermal stimuli. The patient was in severe pain and had also been traumatised by the incident. Additionally, he was not a routine attendee at the practice, although he had gone through removable orthodontic treatment some years previously, but had not completed the course of treatment.

Fortunately, the patient had retrieved the whole fragment of the detached tooth. The fragment had been preserved in milk, which some studies deem better than water or saline in terms of preservation owing to its lower fracture resistance compared to other mediums.⁵ Other studies however, show no difference between storage in water or milk, but instead suggest higher bond strengths when immersed in hypertonic solutions or egg white.⁶Figures 1–3 illustrate the presenting situation where the coronal 50% of tooth material from UL1 had been detached. This injury also resulted in pulp horn exposure that was larger than a simple pinpoint opening. The exposure had been bleeding and was approximately 3 mm in diameter relative to a pinpoint exposure.

Retention of the detached fragment was key to the treatment plan for management. Should a fragment have a satisfactory seat back onto the tooth surface, the fragment can be used. Conversely, should the fragment either be in pieces or not fit well to the tooth surface, re-attachment may not be a predictable method of restoration, in which case, a direct or indirect restoration may be needed.

Figure 4 illustrates the crude re-attachment of the fragment to the tooth surface, showing that it had a satisfactory fit and so it could be prepared for re-attachment. The fragment showed close association to the medial and distal aspects of the underlying tooth, with a slight defect along the mid-buccal aspect. Given the level of available enamel, it was deemed suitable for an attempt to re-attach the fragment and then assess the outcome in the short and long term. It was explained to the patient that at this time that the exposure was too large to provide a direct pulp cap, and so the pulp was extirpated, with a subsequent referral to an endodontist for definitive root canal treatment. Given the nature of the impact, the endodontist had concerns that the bleeding following the impact could result in discolouration of the retained tooth owing to blood in the dentinal tubules. This was discussed and explained to the patient at the time of the root canal treatment consultation.

The fragment was re-attached successfully using a workflow described in Case 2. While the re-attachment resulted in a satisfactory union of fragment and tooth, the underlying tooth discoloured within a few weeks of the root canal treatment. This resulted in the aesthetic result not being consistent with the adjacent dentition. Figures 5 and 6 illustrate the immediate result of re-attachment where a micro-mechanical bond and optical union had been established, resulting in restoration of the primary anatomical form of the tooth. The abundance of enamel also led to a predictable adhesive bond with the underlying tooth, which remains robust.

This case was treated in line with the dental trauma guidelines.⁷ The patient was not concerned about the discolouration at that time. Further reviews at adequate intervals will be required to assess factors, such as internal or external resorption, further discolouration and the need for whitening procedures, as well as ankylosis and long-term occlusal integration. Figure 7 shows the short-term result, once dental and peri-oral tissue healing had taken place. Although the discolouration is obvious, note the continuous line angle formations in relation to the primary anatomical form of UL1.

Case 2

In Case 2, the patient presented after a workplace accident. The patient was an acrobat and had a fall that resulted in fractures to three upper anterior teeth. The patient was not a routine attendee of the practice and required, as per the previous case, an initial comprehensive history and examination. After the fall, the patient had seen an emergency dentist in a secondary care environment and the teeth had been splinted owing to the subluxation, while the tooth fragments of the fractured teeth had been retained. The fragments were whole, rather than in pieces, and had been preserved in hypertonic saline as advised by secondary care as the concentration was greater than 0.9%. The patient was very distressed, but had no further accessory injuries.

Figures 8 and 9 illustrate how this case was different to Case 1. The patient had access to secondary care, had immersed the tooth fragments in saline and (as came to be known) had already had satisfactory root canal treatment to the UL1.

When carrying out the full trauma examination, it was essential that the teeth were inspected for pulpal health, lack of mobility without ankylosis (the wire splint had been in situ for 10 days), further undiagnosed fractures, tooth displacement and occlusal relationships. Figures 10 and 11 illustrate the degree of occlusal clearance when the patient was in maximum intercuspation. In this case, the relationships appeared favourable, and the pulpal health of the UR1 and UL2 appeared good, with responsive sensitivity testing. It was noted that such sensitivity tests could prove misleading in the event of pulpal trauma,⁸ and so the patient was informed that this could change in the future.

The tooth fragments were cleaned by immersing them in saline and then placing them into an ultrasonic bath for 5 minutes, followed by a crude try-in to ensure the fragments related to the tooth surfaces. Once verified, the patient was informed that an attempt would be made to re-attach the fragments given the clinical scenario, and consent was gained for this. The wire splint was also removed and it was confirmed that the underlying teeth were firm in position. The upper anterior sextant was then isolated with rubber dam (UnoDent heavy gauge latex-free) and Wedjets (Coltene, USA). The teeth were then air abraded using 29-micron aluminium oxide powder (Prestige, UK) under a pressure of 4 bar using an Aquacare unit (Velopex, USA). This was carried out to remove the biofilm and ensure clean enamel and dentine for an effective adhesive bond. The peripheral 2-mm margins of enamel were etched using 37% phosphoric acid (Kerr, USA) for 20 seconds. As this was a selective etch protocol, the dentine was left unconditioned at this stage. The etch was then thoroughly washed away over a 20 second period to ensure all colloidal silica from the etchant had been removed. A high-volume suction tip was applied to the teeth to remove any surface moisture without desiccating the exposed dentine.

A universal bonding agent was liberally scrubbed into the exposed dentine and peripheral enamel (i-Bond Universal, Kulzer, Germany). Given the self-etching nature of the bonding agent, this was sufficient to condition the dentine, thus justifying the etching protocol described above. Once the bonding agent had been applied, a gentle air blow ensured a consistent thin coating remained, including removal of the solvent by evaporation. The area was then cured for 40 seconds (Valo, Optident, UK). The thin cross-section of a bonding agent that had no filler content ensured an integral fit of the tooth fragments, which may not always be the case with highly filled bonding agents. The attachments were also air abraded, etched and bonded in the same way to ensure both parts had received the same treatment. The pieces were re-attached using a chromatic nano-hybrid composite that matched the shade of the underlying dentine (this was recorded at the beginning of the clinical session). The nano-hybrid composite was chosen for its easy and predictable handling characteristics, as well as its soft nature (Venus Pearl OLC, Kulzer). This allowed a full and positive seat of the fragments. It was noted that warmed composite, or a flowable format, might also be considered here as alternative resin formats. The rationale for the dentine shade was more to allow a chromatic union that could be finished and polished rather than one in composite enamel that risked a drop in value and a potential grey line. The fragments were fully seated, which was verified visually. The excess was carefully removed and smoothed at the restorative margins using a composite brush with no resin additives (Compobrush, Smile-line, Switzerland) to provide a seamless union. The teeth were then light cured.

The patient was advised before treatment that the teeth and fragments were unlikely to shade match initially owing to dehydration; however, this usually reverses within 36 hours.⁹ The re-attached teeth were then finished using abrasive discs of medium, fine and super-fine grades (Cosmediscs, Cosmedent, USA). It should be noted that these discs were spun at no more than 8000rpm in order to retain control of the tooth surface refinement. Once the excess had been removed, and the surfaces finished down to a super-fine grade, aluminium oxide pre-polishers and diamond paste impregnated tips were used at low revolutions to provide a surface finish and lustre to hide the margin optically. The immediate post-operative photographs (Figures 12 and 13) show the level and degree of dehydration that took place during the clinical procedure.

The patient was given strict instructions to not engage in high-impact physical activities or apply high functional loading to the upper anterior teeth. A review visit was arranged for 3–4 weeks later, where it was hoped that the patient would be symptom free and have a consistent chromatic outcome from an aesthetic perspective.

At the review visit, the rehydration of tooth fragments appeared successful. Only at this point, were we able to note the complexity of the natural incisal edges and how challenging it would have been to use composite resin alone to restore the teeth. The patient was very happy with the functional and aesthetic outcome. Only a very mild presentation of trauma was evident on the facial surfaces of the affected teeth. The patient was advised to consider a guard for performing acrobatics where possible, and to continue to be vigilant for any symptoms or changes that might be experienced, such as pain, discolouration, mobility and swelling. Figures 14 and 15 highlight the post-operative results 4 weeks after the restoration and show a pleasing aesthetic and functional outcome with an excellent degree of biological integration of the tooth fragments, as well as use of a chromatic composite resin to adhere and chromatically hide the reattachment margins. This patient was placed under annual review.¹⁰

Conclusions

The variation of outcome between the two cases is likely to be due to a combination of factors. In Case 1, unlike Case 2, there was a significant pulpal exposure. Case 2 had immediate secondary care, resulting in the wire splint as well as the teeth being stored in saline. Rehydrating a fragment in water or saline is recommended before re-attachment. This moisture has been reported to increase the bond strength, colour, and fracture resistance. The time needed to rehydrate a fragment is reported to be 15–20 minutes.¹¹ It can be difficult to predict the overall outcome of such traumas and so, communication and setting reasonable expectations are key.

It is important to highlight some variations in terms of technique, such as the use of a nano-hybrid composite that had a chromatic, yet soft handling property, which allowed full seating of the tooth fragments. Using a flowable composite may be more predictable in terms of full seating; however, the opacity and chromatics of the composite used allowed the margination to be minimal as shown at the review visit. The maintenance of natural incisal edge anatomy is also maintained with procedures such as this, and, when looked after, may prove to be a better longer-term outcome than many direct restorations.¹² While this cannot be directly compared at this stage, the follow up on such cases will hopefully allow more insight into the success and longevity of such techniques for functional and aesthetic success.