[Expert Lecture] Can teeth be cracked? Cracked teeth, do you know?

What is a cracked tooth

Cracked teeth, also known as tooth microcracks, also known as incomplete tooth fractures, refer to the non-physiological cracks that occur on the surface of the crown and are not easy to find. Shallow fissures generally have no obvious symptoms, but deep cracks may cause sensitivity to cold and heat stimuli, or bite discomfort. Cracked teeth most commonly occur in maxillary molars, followed by mandibular molars and maxillary premolars.

Causes of Cracked Teeth

The etiology of cracked teeth is not completely clear at present, it is believed that it may be related to the following factors

Weak link in tooth tissue structure: When the development defect of tooth tissue can form deep fissures, such as pits and enamel plates, when the teeth perform the chewing function, the parts are prone to stress concentration, resulting in the occurrence of cracked teeth. At the same time, the greater the inclination of the cusp, the greater the horizontal force generated during chewing. Therefore, the inclined surface of the cusp at the part bearing the occlusal force is another susceptibility factor for the occurrence of cracks.

Occlusal Trauma: Cracked teeth are often associated with the patient's history of chewing hard and brittle foods such as ice and hard candy. These patients have developed masticatory muscles. On the one hand, excessive occlusal surface wear is caused by excessive occlusal force, and the slope of the cusp increases significantly; Eventually lead to cracked teeth.

temperature: The expansion coefficients of enamel and dentin are different, and cracks may appear on the surface of enamel under the action of long-term cold and hot temperature cycles in the oral cavity, such as the cracks that occur on the lip and buccal tooth surfaces with low occlusal force and this factor related.

Factors related to dental surgical treatment: dental surgical treatment such as preparation of cavity, pulp opening, etc. often need to remove part of healthy tooth tissue, thereby weakening the tooth's ability to withstand external forces, thermal expansion coefficient and polymerization shrinkage coefficient of filling materials and tooth tissue The difference is also one of the factors that weaken the strength of dentin and cause tooth cracks. After pulpal disease and root canal treatment, the hard tissue of the tooth body loses the most important nutrient supply, and the tissue becomes brittle. If the treatment and full crown restoration are not carried out in time, cracks and fractures are prone to occur.

Clinical features of cracked teeth

Cracked teeth often present with the so-called "cracked tooth syndrome" characterized by painful episodes of chewing (application of pressure or release of pressure) and sharp, brief pains with exposure to heat and cold. Masticatory pain is fixed-point occlusal pain, that is, when the occlusal force acts on the crack line, there will be severe tearing pain, the occlusion stops, and the pain stops. With the development of cracked teeth, when the crack reaches the deep layer of dentin and is close to the pulp cavity, bacteria can enter the pulp cavity along the crack, irritating the pulp, and clinical symptoms of pulpitis appear, ranging from mild pain to severe spontaneous pain, It becomes irreversible pulpitis, pulp necrosis, and apical periodontitis. Once a cracked tooth reaches the pulp, severe pulp or periapical disease may occur, which explains the diversity of clinical symptoms of cracked teeth.

The fissure line overlaps with the developmental groove of the tooth and crosses the marginal ridge on one or both sides to reach the proximal or buccolingual surface of the tooth. The fissure line of maxillary molars often overlaps with the mesial or lingual groove, while the fissure line of mandibular molars overlaps with the developmental groove in the mesio-distal direction, and the fissure line of maxillary premolars also overlaps with the developmental groove in the mesio-distal direction.

Cracked Teeth Prevention

1

Eliminate risk factors

There are many risk factors that lead to cracked teeth, such as night grinding, repairing missing teeth, and biting too hard food. In order to prevent damage to the hard tissue of the teeth, middle-aged and elderly people also need regular oral examinations. Usually, it is absolutely forbidden to use some teeth as tools, to open beer caps at will, or to bite walnuts and other hard foods at will.

2

Avoiding Cracked Teeth in Dental Restoration

When restoring the tooth, we must pay attention to maintaining the correct cusp-socket relationship, and also need to avoid the increase of the splitting force of the too steep cusp on the tooth. In the process of tooth restoration, once some too sharp and too steep cusps are found, they need to be adjusted and removed properly.

3

avoid sports injuries

Cracked teeth are prone to occur during some daily sports exercises, such as some accidents during playing, cycling, and running. Once you touch your teeth, there is a high chance of cracked teeth, so you must pay more attention to exercise safety.

4

Avoid excessive bite force

Tooth treatment or restoration may cause excessive occlusal force or imbalance, which can easily lead to cracked teeth or even tooth splitting. Therefore, when filling teeth or making metal crowns, it is necessary to bite and adjust the occlusal strength of the upper and lower teeth.