The pulp chambers in teeth contain the nerve, blood vessels, and connective tissue. The dental pulp within the chamber is a gel-like consistency consisting of 75 percent water and 25 percent organic materials. The pulp is located between the dentin, enamel, and cementum of a tooth.
Additionally, the dental pulp provides sensory innervation (stimulation) through a tooth’s nerve. However, when it becomes infected, the teeth typically become severely sensitive to sweets, hot, or cold substances.
The pulps in primary teeth are closer to the outer surface, which allows cavities to progress quicker and spread into the dentin more rapidly. This is because primary teeth have thinner enamel than permanent teeth and the thickness of the dentin between the pulp chambers and the enamel is also less.
Types of Pulp Therapy
The type of pulpal therapy needed depends on whether the patient’s dental pulp is vital or nonvital and if the pulp is capable or incapable of healing. Your dentist also evaluates the symptoms associated with the infection and your medical history. The most common pulpal treatments include:
A protective liner is a thinly-applied liquid that covers the pulpal surface of deep carious lesions. Liners protect a child’s primary or permanent tooth after cavity removal and before placing a restoration, such as a filling. The liquid covers the base of the cavity nearest to the pulp and protects the restorative material used to cover the cavity. The liners also promote healing of the pulp tissue, reduce tooth sensitivity, and prevent injuries to the pulp.
Indirect Pulp Treatment (IPT)
This treatment is an alternative to a pulpotomy, but includes similar steps. IPTs treat primary teeth that have deep cavities approaching the dental pulp. During the procedure, your dentist leaves the cavitated dentin around the pulp to avoid pulp exposure. The success rates of IPTs are similar to pulpotomy procedures. Dentists can perform IPTs on both primary and permanent teeth, but the procedures vary depending on the severity of the infection.
This procedure may be recommended if a large, deep cavity is completely removed and the dental pulp becomes exposed. In this case, your dentist will use stepwise excavation instead. During the procedure, they only partially remove the cavity to help prevent pulp exposure. After two to 24 months, your dentist re-opens the cavity, removes the remaining decay, and permanently restores the tooth. Patients who have deep cavities with severe pain, irreversible pulpitis, or experience extreme sensitivity to cold or hot substances are not candidates for this procedure.
Direct Pulp Capping
Direct pulp caps can be placed on primary or permanent teeth. During cavity preparation, a small portion of the dental pulp can become exposed. In this case, your dentist will place a cap over the exposed pulp to protect it from infection. Although, direct pulp capping on primary teeth is not recommended.
A pulpotomy is more invasive than the pulpal treatments listed above and involves the removal of the infected portion of the dental pulp (coronal pulp). Your dentist only preserves the healthy aspects of the pulp tissue. Treatment is necessary if cavity removal results in exposure of the pulp or in a primary tooth with reversible pulpitis, which means the tooth can still be saved.
Pulpectomy (Root Canal)
A pulpectomy is a root canal procedure that involves the complete removal of pulp tissue from a tooth with irreversible pulpitis or necrosis (dead tissue). Pulpectomies rarely treat severely decayed primary or young permanent teeth with irreversible pulpitis, which means the pulp cannot be saved.
Risk Factors: Pulp Exposure and Infection
Risk factors associated with infected dental pulp include:
Severe Tooth Decay — untreated caries (cavities) can lead to severe tooth decay. If the dental pulp becomes infected due to decay, pulp treatment may be necessary.
Tooth Chips or Cracks — teeth grinding and clenching during sleep (bruxism) or a dental injury can cause chips or cracks in tooth enamel. Depending on how large the chip or crack is, the dental pulp may become exposed, which can lead to infection.
Inflammation of Gums Surrounding the Infected Tooth — when the gums become inflamed, it is more likely that the bacteria will travel to the dental pulp.
Large Cavity Fillings — primary or permanent teeth with large cavities and fillings are more prone to pulpal infections.
When is Treatment Necessary?
Signs that a child may need root canal therapy on a primary or permanent tooth include:
Tooth Sensitivity — If sweet, hot, or cold substances cause severe tooth sensitivity (sharp pain).
Severe Toothaches — If a toothache develops when pressure is applied or after chewing.
Gum Swelling — If the gums surrounding the infected tooth are swollen or tender.
Tooth and Gum Discoloration — If the gums, tooth, or both become darker and other symptoms (above) are present.