Molars, located at the back of the mouth, serve as the primary teeth for grinding and crushing food. These strong teeth endure significant daily forces, making them susceptible to damage over time. A fractured molar can be a surprising and uncomfortable event, often accompanied by pain or sensitivity. Understanding the various reasons a molar might break provides insight into both prevention and necessary treatment.
Direct Incidents Leading to Breakage
A molar can fracture due to biting down on an unexpectedly hard object. This impact creates a force exceeding the tooth’s structural integrity. Common culprits include unpopped popcorn kernels, hard candies, ice cubes, or small fruit pits. The concentrated pressure can cause a piece to chip or crack away.
Direct trauma to the mouth can also cause a molar to fracture. This includes falls, sports injuries, or accidents like car collisions. Such events apply external forces that can overwhelm a tooth’s resistance.
Internal Weaknesses and Contributing Factors
Molars often fracture due to underlying conditions that compromise their strength over time, making them vulnerable to routine chewing forces. Extensive dental decay gradually erodes enamel and dentin, creating hollowed-out areas. As decay progresses, the remaining tooth structure becomes thinner and weaker. This compromised state prevents the tooth from withstanding normal biting and chewing pressures without fracturing.
Large or aging dental fillings can also contribute to molar fractures. Over time, amalgam or composite fillings expand and contract with temperature changes, stressing the surrounding tooth structure. Large fillings may have required significant removal of original tooth material, leaving less to absorb chewing forces. This can lead to cracks developing around the filling, eventually causing a portion of the tooth to break.
Bruxism, the involuntary grinding or clenching of teeth, exerts sustained pressure on molars. This habit, often occurring unconsciously during sleep, subjects teeth to forces greater than normal eating. The repetitive stress can lead to hairline cracks in the enamel and dentin, gradually weakening the tooth. Over time, these micro-fractures can propagate, leading to a significant fracture.
Molars that have undergone root canal treatment can become more brittle and susceptible to fracture. A root canal involves removing the tooth’s pulp. This procedure can dehydrate the tooth structure, making it less resilient. Additionally, tooth structure is often removed during access preparation, further diminishing the tooth’s strength.
Natural wear and tear associated with aging also weakens molars. Decades of chewing gradually erode enamel and dentin. This cumulative stress, combined with the drying of tooth structure over time, reduces a molar’s resistance to fracture. Older teeth are less flexible and more prone to cracking.
How Molars Fracture
Molars can fracture in several patterns, with the type of break often providing clues about its origin and extent. A common type is a cusp fracture, where a piece of the chewing surface breaks off. This occurs when a weakened cusp cannot withstand biting forces. Patients experience pain when biting down or when the tooth is exposed to cold.
Cracked Tooth Syndrome involves an incomplete fracture that extends through the tooth’s crown. These cracks can be difficult to detect. Individuals report intermittent pain when chewing or sensitivity to temperature changes. The crack can eventually progress deeper into the tooth structure.
When a crack extends completely through the tooth, separating it, it is termed a split tooth. This fracture originates from an untreated cracked tooth. A split tooth causes pain and sensitivity. This condition necessitates extraction of the affected molar.
Vertical root fractures originate in the tooth’s root and extend upwards towards the chewing surface. These fractures are challenging to diagnose as they are hidden beneath the gum line. They occur in teeth that have undergone root canal treatment or those subjected to excessive biting forces. Symptoms include persistent pain, sensitivity to temperature changes, and localized swelling. A pocket between the gum and the tooth can form near the fracture site.