One of the biggest facets of endodontic care is understanding tooth anatomy. Each person’s set of teeth is individually unique, and endodontists tend to focus on how the tooth’s shape, morphology, and sections can be approached to provide patients with the care they need. The root canal system by itself is an entire area of study to how much variety and anomalies can occur in it. Restoring compromised teeth has to account for these anomalies. Endodontists have many techniques to assess the tooth’s condition, understand how their tooth shape impacts their treatment, and how these variations contribute to the different techniques commonly used in endodontic care.
How Do Root Canals Affect Endodontic Care?
Understanding how root canal shapes can vary is one of the many parts that make endodontic care distinct from other practices. Many dentists have classification systems for defining root canal shapes when attempting to treat compromised teeth. By identifying these shapes, dentists can work to treat infected or damaged teeth by accurately defining the areas of injury, defining the access points for treatment, and accounting for risks when performing that treatment. Through this classification system, most root canal shapes can be defined in the following ways:
- Tubular Canals: Tubular canals are pipe-shaped canals with deeper iterations than other teeth. Teeth types, such as the maxillary incisors, mandibular canines, maxillary first premolars, and maxillary first molars, contain these types of canals, and tubular canals are sometimes referred to as a parent class for other root canal shapes.
- Oval and Round Canals: Oval and round canals are often found within teeth types such as the mandibular canines, maxillary incisors, and mandibular first premolars. They’re smaller with circular openings and are considered easiest to treat due to their ease of accessibility.
- Triangular Canals: Triangular canals tend to be rare, but when found, they typically occur within the maxillary canines. These narrow spaces tend to require extra amounts of consideration when preparing for treatment.
- Straight Canals: Straight canals lack the space needed for endodontic treatment due to their size and depth and are most commonly found within the mandibular first premolars. These canal shapes require specific approaches due to the tight, small space provided but are not as common as oval or round canals.
- Semilunar Canals: Semilunar canals, or crescent-shaped canals, are a rare shape but typically occur within teeth types such as the maxillary canals. These canal shapes tend to also occur in conjunction or completely replace triangular canals.
- Infinity or “8”-shaped canals: The eight-shaped canals extend to the outer areas of the tooth but then narrow at the center. These canal shapes are found within tooth types such as the mandibular incisors, mandibular canines, and the maxillary first and second premolars. Due to their variations, they are considered somewhat rare to encounter.
These root canal shapes often dictate how endodontists interact with their patient’s dental care. Although accommodating the varieties in root canal shape can be a challenging task for some, certain techniques can be used to help provide better healing in cases of complex tooth trauma. One primary category often used by endodontists is fiber posts.
How Fiber Posts and Root Canal Shapes Connect
Fiber posts are dental materials used to replace and support the inner root canal when it is severely damaged. Fiber post treatments work to increase the resistance against fractures, prevent tooth loss, reduce the need for implants, and provide the tooth with a solid foundation for stability. Fiber posts are commonly used when treating damaged teeth as a way to endodontically restore them and, overall, assist with other restorative methods such as crowns, veneers, and onlays.
However, one keynote to consider is the techniques that are incorporated with fiber post-treatments, as the shape of the root canal can affect the overall outcome of the treatment. Although fiber post materials have similar elasticities to dentin material and can reduce overall damage, not accounting for the shape of the canal can dramatically reduce its overall success rate and increase its failure rates. Techniques performed by endodontists are all specific to the dentist’s practice, but fiber post techniques can be used to accommodate the tooth’s shape and be used to correct problems relating to complex endodontic cases.
Here’s a small list of fiber post techniques that provide examples of how canal shapes can be accommodated to effective treat endodontically compromised teeth:
- The Simple Canal Technique: The simple canal technique provides effective means of canal preparation for oval, round, tubular, and even triangular shapes through the use of a bottom-up approach. By matching the drill size with the fiber posts, endodontists can effectively provide a straightforward treatment module that enhances its bonding, setting, and curing capabilities.
- Anatomical Post and Core Technique: The post and core technique works primarily for oval canal shapes, but for teeth traumatically compromised where the bottom build-up method cannot work, this method is replaced by building up core materials to replace those deficiencies. By using core materials, the fiber post can be prepared and isolated for further treatment.
- Post and Accessory Post Technique: Lastly, the post and accessory technique are typically used for unusually shaped canal spaces, such as the crescent, triangular, figure eight, and straight canals. Because of the unusual space, wider spaces are required to provide more internal support for the affected tooth, and to provide internal space; additional fiber posts are added to contribute to the tooth’s overall compression strength.
These examples of fiber post techniques are just a few examples of the efforts being made to accommodate endodontically damaged teeth. Through the overall goal of creating fracture resistance, endodontists can work to reduce the rate of shrinkage and remove the need for overall tooth extractions for unstable teeth. Tooth canal shapes contribute greatly to the process of treating teeth, and an endodontic approach can help create healthier smiles for everyone through its careful consideration and thoughtful approach to tooth care.
