Partial Pulpotomy

 This is Dr. Cal Shipley with a review of partial pulpotomy. Partial pulpotomy is a technique which is used primarily in primary, also known as deciduous teeth, or in immature permanent teeth in children.

In situations where only a portion of the dental pulp has become diseased, the objective of partial pulpotomy is to remove only the diseased portion of the pulp, leaving the healthy tissue intact. I’ll be discussing the advantages of leaving the healthy pulp tissue intact in a moment.

Dental Anatomy

First, let’s take a look at some basic dental anatomy. The fully erupted primary teeth consist of 20 teeth total, 10 upper and 10 lower. The primary teeth are designated by a standard lettering system as shown here.

For the purposes of this presentation, I’m going to focus on tooth E, also known as the right-upper central incisor. Looking at a cross-sectional view of the incisor, the outer protective layer of the tooth is called the enamel. Deep to the enamel and providing the primary structural support for the tooth is the dentin.

Pulp Chamber

Located in the very center of the tooth is the pulp chamber. Within the pulp chamber lies the pulp, which consists of arteries which supply nourishing blood to all the dental tissues; nerves which provide sensation; and veins, which return blood back to the circulatory system.

Rotating our view to an end on perspective, also known as an incisal view, in cross-section, we again see the relationships of enamel, dentin and the pulp chamber containing arteries, nerves and veins.

Tooth Decay and Pulpitis

Now, let’s turn to the concept of tooth decay and pulpitis. The mouth contains abundant bacteria, many of which are beneficial, and some of which are potentially harmful. Rotating to an incisal view of tooth E and looking in cross-section, we again see the central pulp chamber containing the pulp. Zooming into a microscopic view reveals the bacterium Streptococcus Mutans interfacing with the enamel. Strep mutans is the primary bacterium responsible for tooth decay.

Streptococcus Mutans and Plaque

Under normal circumstances, the growth of Strep mutans is kept in check through competition for nutrients by other bacteria in the mouth. However, in the presence of excessive amounts of sugars in the mouth, such as sucrose, Strep mutans can produce a sticky film known as plaque, which adheres to the enamel and provides a protective environment within which the bacteria can thrive. The bacteria produce acids which remove minerals from the enamel. The demineralization process initially causes deep pigmented areas to occur on the enamel surface. A steady supply of sugars eventually results in decay of the enamel.

From the incisal view, in cross-section, we can observe the steady erosion of the enamel layer as the process of decay continues. Once the enamel layer has been completely destroyed, the acids produced by Strep mutans begin to eat through the dentin. This entire process is known as cavity formation.

Pulpitis

Once the dentin layer has been destroyed, the pulp chamber is exposed, allowing bacteria and acids to access the pulp. If the cavity is left untreated, the bacteria and acids cause severe inflammation of the pulp known as pulpitis.

Looking at a cross-sectional view of the tooth from the front, we can see that the process of pulpitis initially affects only the so-called coronal portion of the pulp. At this stage of the process, the radicular portion of the pulp remains unaffected and healthy.

The fact that the radicular pulp is still healthy in the early stages of the process of pulpitis is the key to the effectiveness of the partial pulpotomy procedure. In the partial pulpotomy procedure, only the diseased coronal pulp is removed, leaving the healthy radicular pulp intact.

Advantages of Partial Pulpotomy

Leaving the healthy radicular pulp intact maintains the blood supply to the root area of the tooth. This provides important protections for primary or immature permanent teeth in children, including resistance to early-onset periodontal disease or infection, also known as gingivitis, and when performed on primary teeth, proper root development and spacing of permanent teeth. Particularly in children who have multiple cavities affecting the pulp chamber, use of the partial pulpotomy procedure can have a profound effect on future dental development and health.

Partial Pulptomy Procedure

Now, let’s take a look at the partial pulpotomy procedure. Again, we’ll focus on tooth E.

After administration of a local anesthetic, a drill is used to remove the damaged portions of enamel and dentin from the tooth. This exposes the diseased portion of the pulp. A drill is then used to remove the diseased pulp. The diseased pulp may also be removed by electrocautery or laser-based techniques.

This process results in some bleeding from the remaining healthy pulp. Switching to a frontal view in cross-section, the coronal diseased pulp has been removed while the healthy radicular pulp remains. A cotton pellet soaked in Buckley’s Solution is packed into the pulp chamber. Buckley’s solution is a dilute form of a compound known as Formocresol whose active ingredients are formaldehyde and cresol. The primary action of Buckley’s solution is to eliminate bacterial infection within the pulp chamber.

Once inserted, the cotton pellet also acts to tamponade any bleeding which may be occurring from the remaining pulp. The cotton pellet is left in the pulp chamber for several minutes while the tooth is prepared for crown placement.

Crown Placement

The cotton pellet is then removed and zinc oxide-eugenol putty, also known as ZOE putty, is inserted to fill and seal the chamber. In addition to being a good sealant, ZOE putty has both anesthetic and antiseptic properties.

The final step in the partial pulpotomy procedure is the application of a permanent crown.

Cal Shipley, M.D. copyright 2020