An enamel fracture is when the outermost layer of the

tooth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tea ...

is cracked, without damaging the inner layers including the

dentin Dentin ( ) (American English) or dentine ( or ) (British English) () is a calcified tissue (biology), tissue of the body and, along with tooth enamel, enamel, cementum, and pulp (tooth), pulp, is one of the four major components of teeth. It i ...

e or

pulp Pulp may refer to: * Pulp (fruit), the inner flesh of fruit * Pulp (band), an English rock band Engineering * Pulp (paper), the fibrous material used to make paper * Dissolving pulp, highly purified cellulose used in fibre and film manufacture ...

. This can happen from trauma such as a fall where the teeth are impacted by a hard object causing a chip to occur. The term “craze lines” and " enamel infraction" are also used to describe minute incomplete cracks exclusive to the enamel surface.

Introduction

An enamel fracture occurs when the outer layer of the tooth, known as enamel, is fractured without directly impacting the underlying tooth tissues of the

e or

. This phenomenon typically arises from hard, external forces impacting the tooth to induce enamel breakage. These fractures are often characterised by irregular breaks on the biting surface of the tooth, in contrast to the smoother surfaces associated with typical tooth degradation. Enamel fractures can vary in severity, ranging from minor cosmetic issues to more significant structural problems. An enamel fracture typically doesn't cause any noticeable symptoms such as tenderness or an increase in mobility. However, if sensitivity and mobility are present, it may indicate an enamel-dentine fracture or a root fracture.

Aetiology

Enamel fractures commonly result from direct impacts to the tooth, often occurring due to a variety of accidents. These accidents encompass a broad spectrum of situations, including sports-related injuries, cycling mishaps, motor vehicle collisions, and physical altercations. Notably, falls stand out as a major factor, responsible for the majority of dental enamel fractures. The severity of the damage inflicted on the tooth correlates directly with the energy, magnitude, shape, and direction of the impacting force. Enamel fractures can also arise from

malocclusion In orthodontics, a malocclusion is a misalignment or incorrect relation between the teeth of the upper and lower dental arches when they approach each other as the jaws close. The English-language term dates from 1864; Edward Angle (1855–1 ...

which is when the teeth do not align as properly as they should. This can result in excessive pressure on some areas of the teeth, particularly during chewing or grinding, which increases the risk of enamel fractures occurring.

Classifications

Various terms and classifications are used to differentiate types of tooth fractures; however, a limited number applies exclusively to enamel fractures. This limitation arrives from the sole effect on the outer tooth layer in enamel fractures, independent from the underlying

e or

. According to the Ellis Classification System for Enamel Fractures, a fracture involving only the enamel is categorised as a Class I fracture. Class I fractures can be further described as either vertical or horizontal, and as complete or incomplete. Patients affected by such fractures do not typically experience pain in response to temperature, air, or tapping (percussion) on the fractured tooth. The term “craze lines” is also used to describe minute cracks exclusive to the enamel surface.

Diagnosis

Early detection plays a pivotal role in stopping fracture progression. Various diagnostic techniques are available to localise and assess the direction of the fracture, including clinical examinations,

transillumination Transillumination is the technique of sample illumination by transmission of light through the sample. Transillumination is used in a variety of methods of imaging. Microscopy In microscopy transillumination refers to the illumination of a sample ...

and bite tests. Moreover, recent advancements in diagnostic methods, such as optical coherence tomography (OCT) and near-infrared imaging, offer potential diagnostic tools for improved detection and evaluation.

1. Clinical examination

Clinical examination with visual inspections can help dentists localise potential defects in the tooth. Magnifying

loupe A loupe ( ) is a simple, small magnification device used to see small details more closely. They generally have higher magnification than a magnifying glass, and are designed to be held or worn close to the eye. A loupe does not have an attached ...

s might be required for enhanced visualisation. Limitations include the limited accessibility to severity and depth of fracture planes. Old restorations and staining are advised to be removed for clearer visualisation. Additionally, the

dentist A dentist, also known as a dental doctor, dental physician, dental surgeon, is a health care professional who specializes in dentistry, the branch of medicine focused on the teeth, gums, and mouth. The dentist's supporting team aids in provi ...

may test for pain on percussion (by tapping the teeth with the end of the mirror to assess whether the tooth is painful) or palpation (of the gum to assess whether there is pain which may indicate an infection). The dentist may check is the tooth has a vital nerve supply, these tests may include sensibility testing, such as electrical pulp testing or thermal testing. Transillumination of tooth marked

2. Transillumination

Transillumination Transillumination is the technique of sample illumination by transmission of light through the sample. Transillumination is used in a variety of methods of imaging. Microscopy In microscopy transillumination refers to the illumination of a sample ...

aids in locating the fracture plane by diffracting light from the

LED light An LED lamp or LED light is an electric light that produces light using light-emitting diodes (LEDs). LED lamps are significantly more Electrical efficiency, energy-efficient than equivalent Incandescent light bulb, incandescent lamps and f ...

source. Transillumination will show the enamel fracture to appear darker compared to the rest of the tooth due to the light not passing through. Yellow and orange light are best to enhance diagnostic accuracy. It is advised to remove former restorations before assessment and diagnosis to properly assess the tooth.

3. Radiographic assessment

When a tooth is fractured, small parts of the enamel is lost, the missing enamel should be accounted for, if the fragment cannot be found the patient's lip should be examined thoroughly to assess for the possibility it remains in the lip. This assessment can be achieved via

radiographs Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiography and "therapeu ...

. Radiographs of the tooth are indicated to assess the extent of the fracture, one parallel

periapical Dental anatomy is a field of anatomy dedicated to the study of human tooth structures. The development, appearance, and classification of teeth fall within its purview. (The function of teeth as they contact one another falls elsewhere, under de ...

radiograph should be taken, this is a radiograph showing the whole tooth including the

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, parti ...

, root and

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

Recent Advances and potential diagnostic tools

The following technology is still being researched and is not available for general dental practice.

Optical coherence tomography

Optical coherence

tomography Tomography is imaging by sections or sectioning that uses any kind of penetrating wave. The method is used in radiology, archaeology, biology, atmospheric science, geophysics, oceanography, plasma physics, materials science, cosmochemistry, ast ...

(OCT) is a non-invasive and non-destructive imaging technology. It uses

infrared light Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those o ...

waves to provide high-resolution images of internal structures. Studies have suggested swept-source optical coherence

(SSOCT) as a potential diagnostic tool, given the high image-producing speed and the high sensitivity in detecting fractures and

decay Decay may refer to: Science and technology * Bit decay, in computing * Decay time (fall time), in electronics * Distance decay, in geography * Software decay, in computing Biology * Decomposition of organic matter * Mitochondrial decay, in g ...

within the enamel layer.

Treatment

In cases of a simple enamel fracture, the recommended approach is to reattach the broken tooth fragment, if it is possible. Following reattachment, smoothing of the edges is undertaken. Depending on the extent of the fractured portion, a choice is made between a

glass ionomer Glass is an amorphous ( non-crystalline) solid. Because it is often transparent and chemically inert, glass has found widespread practical, technological, and decorative use in window panes, tableware, and optics. Some common objects made o ...

or permanent restoration, such as

composite resin Dental composite resins (better referred to as "resin-based composites" or simply "filled resins") are dental cements made of synthetic resins. Synthetic resins evolved as restorative materials since they were insoluble, of good tooth-like appe ...

, to ensure structural integrity and good aesthetics. If the enamel fracture is small, then the tooth edges can be smoothed without requiring a restoration. If the enamel fracture is mild, there is no advisement for subsequent follow-up appointments. However, if the fracture is large the

may want to review the restoration and monitor the tooth for any potential complications, including

pulp necrosis Pulp necrosis is a clinical diagnostic category indicating the death of cells and tissues in the pulp chamber of a tooth with or without bacterial invasion. It is often the result of many cases of dental trauma, caries and irreversible pulpitis ...

, which represents an extreme outcome of an enamel fracture characterized by the death of the

tooth pulp A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearin ...

. Early detection and intervention are pivotal in ensuring optimal outcomes and maintaining oral health following dental trauma.

References

{{reflist Acquired tooth disorders Emergency medicine