A cracked tooth beneath a dental crown represents a complex challenge in dentistry. A dental crown, designed to protect a damaged tooth, can sometimes mask a crack in the underlying natural tooth structure. This issue can arise from various factors, including the forces of chewing, teeth grinding, or trauma. The ability to save such a tooth depends on the nature and extent of the crack.
Identifying a Cracked Tooth Under a Crown
Recognizing a cracked tooth under a crown can be difficult, as symptoms are often subtle or mimic other dental problems. Individuals might experience pain when biting or chewing, particularly when releasing the bite, or heightened sensitivity to hot or cold temperatures. This discomfort can be intermittent, making identification of the affected tooth challenging for the dentist. Swelling around the gum tissue near the tooth may also indicate a problem.
Dentists employ various diagnostic techniques to identify a crack. Visual inspection, aided by magnification and transillumination, can reveal fine lines or discolorations. A dental explorer can feel for irregularities or catch in a crack. Biting tests, using tools like a “Tooth Slooth” or cotton rolls, pinpoint pain by applying pressure to individual cusps.
While X-rays are a common diagnostic tool, they frequently do not show cracks, especially fine or vertical fractures, because the crack line may not be visible on a two-dimensional image. However, advanced imaging techniques like cone-beam computed tomography (CBCT) can provide three-dimensional views, helping to detect vertical splits or bone loss associated with a crack. Staining the tooth with a special dye can also make subtle cracks more visible. In some instances, removing the existing crown is necessary for a direct visual and tactile assessment of the underlying tooth.
Factors Determining Salvageability
The depth and location of the crack are primary determinants of prognosis. Cracks confined to the outer layers of the tooth, such as the enamel or superficial dentin, generally have a better chance of successful treatment compared to those extending deeper. If the crack extends into the pulp, the soft inner tissue containing nerves and blood vessels, it can lead to irreversible inflammation or infection, complicating the prognosis.
A crack that reaches below the gum line or into the root of the tooth presents a challenging scenario. Cracks extending into the root, especially vertical root fractures, often compromise the tooth’s structural integrity beyond repair. The presence of infection, such as a dental abscess, further diminishes the tooth’s salvageability. Infections can spread, causing pain and leading to severe health issues if left untreated.
The overall health of the tooth structure surrounding the crack also plays a role. If the tooth is already weakened by extensive decay or previous large fillings, it may be less capable of withstanding the stresses of a crack and subsequent repair. Early detection and intervention are crucial, as a crack that is left untreated will likely progress, making saving the tooth increasingly difficult or impossible. Prompt assessment by a dental professional is essential to determine the damage and likelihood of successful treatment.
Treatment Options for Saving the Tooth
When a cracked tooth under a crown can be saved, the treatment approach is tailored to the crack’s severity and location. If the crack has reached the pulp, root canal therapy is often necessary to remove infected or inflamed tissue and preserve the tooth. After the root canal, a new crown is typically placed to protect the weakened tooth from further fracturing and restore its function.
For minor, superficial cracks that do not involve the pulp, dental bonding might be considered. This procedure involves applying a tooth-colored composite resin to the cracked area, which is then sculpted and hardened with a special light to strengthen the tooth and improve its appearance. While bonding can be effective for small cracks, it is not as strong as a crown and is more susceptible to staining or chipping. In some cases, a new crown placement alone may suffice if the crack is superficial and the underlying tooth structure remains sound after addressing the crack.
Dental splinting offers another method for stabilizing cracked teeth, particularly those with medium cracks or mobility. This technique involves bonding the affected tooth to adjacent healthy teeth, providing support and preventing movement that could worsen the crack. The splint, often made with composite resin and reinforced with fiber, helps to stabilize the tooth while surrounding tissues heal. Orthodontic extrusion is a specialized technique used in specific situations where a crack extends slightly below the gum line but is still above the bone. This procedure gently pulls the tooth out of its socket over time, exposing the cracked margin so it can be properly restored with a new crown or filling.
When a Tooth Cannot Be Saved
There are instances when a cracked tooth under a crown cannot be salvaged. This decision is typically made when the crack extends deeply into the tooth structure, such as into the root, or when it causes the tooth to split completely into two parts. Severe infection that cannot be resolved with conservative treatments or irreversible damage to the tooth’s supporting bone often necessitates removal. In such cases, attempting to save the tooth could lead to ongoing pain, persistent infection, or further complications.
When extraction is necessary, several options are available to replace the missing tooth and maintain oral function and aesthetics. A dental implant is a common long-term solution, involving a surgical procedure to place a titanium post into the jawbone, which then fuses with the bone to create a stable foundation for a prosthetic crown. This option most closely mimics a natural tooth and helps preserve jawbone density.
Another alternative is a dental bridge, which consists of one or more artificial teeth held in place by crowns on adjacent natural teeth. This option effectively fills the gap left by the extracted tooth, distributing chewing forces across the supporting teeth. While effective, it requires modifying the neighboring teeth to support the bridge. The choice of replacement depends on individual patient needs, oral health, and preferences, with the goal of restoring a complete and functional smile.