Tooth Fracture

Etiology

Traumatic dental injuries result from direct or indirect impact, with severity influenced by the energy, direction, and shape of the impacting object, as well as the response of the surrounding tissues. Falls are the most common cause, accounting for up to 65% of cases, followed by sports injuries, cycling accidents, motor vehicle accidents, and physical violence.[3][4] Sports-related trauma is more frequent in teenagers, while violence-related injuries peak between ages 21 and 25.[5]  In primary dentition, falls and collisions are the leading causes. Dental caries increase susceptibility to fractures, even with minimal trauma. Patients with increased overjet or lip incompetence are at significantly higher risk of upper incisor injuries.[6]

Epidemiology

Oral traumatic injuries account for 5% of all body injuries across age groups but represent approximately 17% of total injuries in children.[7] These injuries occur more frequently in male than female individuals. More than 75% of tooth fractures affect the upper jaw, with over half involving central incisors, followed by lateral incisors and canines. The maxillary central and lateral incisors are the most commonly fractured teeth due to their anatomic position in the oral cavity.[8] Single-tooth fractures are more common than multiple-tooth fractures, which are typically associated with sports injuries, traffic accidents, and physical violence.

Dental trauma is more frequent in permanent dentition than in primary dentition. The prevalence of tooth fractures ranges from 9.4% to 41.6% in deciduous teeth and 6.1% to 58.6% in permanent teeth.[9]

History and Physical

Dental fractures are classified based on the extent of enamel, dentin, pulp, and root involvement. This classification is essential for guiding treatment decisions, determining prognosis, and preventing complications.

Enamel Infractions 

Enamel infractions are microcracks in the enamel without tooth structure loss and are usually asymptomatic. Enamel infractions are diagnosed by transillumination and must be distinguished from thermal attack cracks, which do not require treatment. Clinically, these teeth exhibit a normal response to pulp vitality tests, no tooth mobility, and no involvement of the periapical tissues. Therefore, these teeth are not sensitive to percussion. X-rays are unremarkable.

Enamel Fractures

Enamel fractures, classified as uncomplicated crown fractures, are confined to the enamel and do not expose dentin or pulp. These fractures typically occur at a proximal angle or the incisal edge of the anterior region. Pulp sensitivity test results and tooth mobility are usually normal. Radiographic examination reveals the extent of enamel loss.

Enamel-Dentin Fractures

Enamel-dentin fractures are another form of uncomplicated crown fracture, extending into dentin without exposing the dental pulp. The tooth remains vital, with no sensitivity to percussion and no mobility.

Enamel-Dentin Fractures with Pulp Exposure

Enamel-dentin fractures with pulp exposure, classified as complicated crown fractures, present clinically with a missing crown structure and an exposed pulp. The tooth is sensitive to air, temperature, and pressure due to the exposed pulp and sectioned dentinal tubules. Pulp testing is generally positive unless a concurrent luxation injury is present.

Crown-Root Fractures

This type of fracture extends apically to the cementoenamel junction and may or may not involve the pulp. Diagnosis relies on clinical and radiographic evaluation. Crown-root fractures extend below the gingival margin, but their apical extent is often difficult to visualize. In most cases, a fractured fragment remains attached and is mobile, causing sensitivity to percussion and pressure. If the fragment is missing, the tooth’s response will depend on the extent of pulp involvement.[10]

Recommended imaging includes a parallel periapical radiograph, 2 additional views with different vertical and horizontal angulations, and an occlusal x-ray. A cone-beam computed tomography (CBCT) is encouraged for a more detailed assessment of the fracture and treatment options.

Root Fractures

Root fractures involve dentin, pulp, and cementum and may present as horizontal, oblique, or a combination of both. Clinical findings include bleeding from the gingival sulcus, tenderness on percussion, and a mobile crown fragment that may be displaced. Pulp testing may initially yield no response due to temporary or permanent neural injury.

Radiographic examination is essential for determining the location and extent of the fracture. Recommended imaging includes a parallel periapical radiograph, 2 additional views with different vertical and horizontal angulations, and an occlusal x-ray. A CBCT scan is advised if these radiographs do not provide sufficient information for diagnosis and treatment planning. If a tooth fragment is missing and the patient has soft tissue injuries, additional x-rays of the lips and cheeks are recommended to locate the fragment.[11]

Evaluation

The need for radiographs should be determined based on whether the information obtained will affect management and whether radiation exposure is warranted. In dental trauma cases, radiographs are typically recommended since root fractures may not always present with clinical signs and symptoms and may otherwise be missed.

Various x-ray projections and angulations should be selected based on clinical judgment and the specific characteristics of each case. A parallel periapical radiograph directed at the injured tooth is usually the first image taken and serves as a reliable starting point. The use of x-ray holders is strongly recommended, as they help establish a reproducible baseline for comparison with follow-up radiographs. Additional images with different angulations are important, as some fractures may not be detected with a single view. An occlusal projection provides a view of the occlusal plane, which is particularly useful for diagnosing root fractures, lateral luxations, and alveolar bone fractures.

CBCT accurately determines the extension, location, and direction of a fracture. This modality helps improve treatment outcomes in complex cases, such as crown-root fractures, root fractures, and luxation injuries.[12]

For a thorough assessment, 3 parallel periapical views are recommended. An additional occlusal x-ray may be taken depending on the case. Table 1 outlines radiographic recommendations focused on evaluating a maxillary central incisor, which is the most commonly fractured tooth (see Table 1. Recommended Radiographic Projections for Evaluating a Maxillary Central Incisor Fracture). However, these recommendations can be applied to other teeth in the dental arch as needed.

Table 1. Recommended Radiographic Projections for Evaluating a Maxillary Central Incisor Fracture

Treatment / Management

Initial Measures

Soft tissue injuries, including swelling, hematoma, and lacerations, often accompany tooth fractures. Applying cold packs to the injured area helps reduce pain and swelling.

Enamel Infraction

Most cases do not require treatment. However, more severe cracks require etching and sealing with bonding resin to prevent bacterial contamination and discoloration.[13]

Enamel Fracture

Treatment options depend on fragment availability and the extent of the lesion. The tooth fragment may be reattached, the edges may be smoothed, and the defect may be restored with resin composite. Clinical and radiographic follow-up is recommended after 2 months and again at 1 year to assess the restoration and look for signs of pulp necrosis, apical periodontitis, and, in immature teeth, impaired root development.

Enamel-Dentin Fracture

Exposed dentinal tubules must be sealed with a bonding agent and restored with composite resin or glass ionomer. If the exposed dentin is close to the pulp, indicated by a slight pink hue without bleeding, calcium hydroxide may be used as a lining material before placing a glass ionomer cement restoration.

If the tooth fragment is available, reattachment should be considered. The fragment must be soaked in water or saline solution for 20 minutes before the procedure to restore tissue hydration. Other treatment options include direct composite restoration, composite restoration with a waxup, and porcelain and resin-based indirect restorations.

Enamel-Dentin Fracture with Pulp Exposure

The management of complicated crown fractures begins with addressing pulp exposure before reconstructing the lost dental structure. A conservative approach is preferred, as teeth can form a dentinal bridge after pulp exposure when treated with a pulp-capping material.

Pulp treatment

Pulp therapy techniques aim to protect the exposed or traumatized dental pulp, with the primary goal of preserving tooth vitality. The choice of treatment depends on several factors, including the duration and diameter of exposure, the pulp's condition before the injury, the tooth’s age, the stage of root development, and the presence of simultaneous luxation injuries.

Pulp capping

Also known as direct pulp protection, pulp capping involves applying a material with regenerative properties, commonly calcium hydroxide, to small pulp exposures. This technique is indicated when the pulp has been exposed for a short duration, as prolonged exposure increases the risk of bacterial invasion and irreversible inflammation.[14] Clinically, the exposure diameter should not exceed 1.5 mm. The likelihood of success is greater in teeth with healthy pulp before the trauma, immature teeth with open apices, younger teeth, and fractures without concomitant luxation injuries.[15](B3)

Partial pulpotomy

Partial pulpotomy involves amputating the pulp 2 mm below the exposure site, where the tissue is presumed to be healthy.[16] This technique is the treatment of choice for young teeth with open apices when pulp capping is contraindicated, such as when excessive time has elapsed since the trauma or when the exposure diameter is too large. Partial pulpotomy serves as a provisional yet long-term approach, allowing the tooth to remain vital for as long as possible. However, root canal treatment followed by appropriate restoration may eventually be required. Restorative options include freehand or indirect composite resin restoration, fragment reattachment if available, and ceramic restoration.

Pulp testing and radiographic evaluation are recommended during follow-up visits at 6 to 8 weeks, 3 months, 5 months, and 1 year. Each follow-up appointment should include a clinical and radiographic assessment to evaluate pulp vitality and identify any complications.

Crown-Root Fractures 

Treatment goals include exposing the fracture margins to facilitate bleeding control, maintaining moisture control during clinical procedures, and improving the patient's ability to manage plaque. Management begins with removing the tooth fragment to assess the full extent of the fracture and pulp involvement. If conditions allow, the fragment may be reattached later.

If the pulp remains unexposed, the exposed dentin can be covered with glass ionomer or composite resin after retrieving the fragment. This conservative approach is viable as long as the fracture extends only slightly apical to the cementoenamel junction.[17]

The primary challenge in the restorative management of crown-root fractures is ensuring restorability, as subgingival margins often necessitate additional treatment to expose more tooth structure and establish a ferrule. Treatment options include gingivectomy, with osteotomy if required, orthodontic extrusion with or without gingivoplasty, forced surgical extrusion, vital root submergence, intentional replantation with or without root rotation, autotransplantation, and extraction.

Clinical and radiographic follow-up examinations should be conducted at 1 week, 6 to 8 weeks, 3 months, 6 months, and 1 year. After the 1st year, annual evaluations should continue for a minimum of 5 years.

Root Fractures

Initial management of root fractures involves repositioning the displaced crown fragment and confirming proper alignment with an x-ray. Endodontic treatment should not be performed during the emergency appointment. The crown fragment should not be removed because fractures at the cervical level can heal.

The mobile segment must be stabilized with a flexible, passive splint for up to 4 weeks, with an extended splinting period for fractures in the cervical 3rd. Fracture healing should be monitored at follow-up visits after 4 weeks when the splint is removed, then at 6 to 8 weeks, 4 months, 6 months, 1 year, and annually for at least 5 years.

Differential Diagnosis

A rigorous clinical and radiographic examination usually gives an accurate diagnosis of tooth fractures. In primary teeth, root fractures should be differentiated from physiological root resorption.[18] Tenderness may be a sign of a simultaneous luxation lesion or root fracture.

Prognosis

The prognosis of a fractured tooth depends on the type of injury, any delay in treatment, and the quality of care provided. Successful management aims to achieve normal healing of the pulp and periodontal tissues. The initial healing process takes approximately 1 to 2 weeks. Minor fractures confined to the enamel have a better prognosis, whereas deeper, untreated fractures may lead to infection and abscess formation.

Complications

Tooth fractures can lead to various complications, including pulp necrosis, crown discoloration, abscess formation, pulpal obliteration, and internal or external root resorption. Pulp necrosis is the most frequently reported complication.