Endodontics and Exodontics

• Endodontics involves treating the pulp to maintain the integrity of a tooth. Treatment usually involves removing some or all of the pulp and then restoring the surface of the tooth.
• Exodontics involves the removal of the entire tooth. Some extractions require minimal elevation, while others require gingival incisions and surgical removal of bone. Exodontics may require gingival incisions and surgical removal of bone.

Pulp & Pulpitis

• Pulp consists of blood vessels, nerves, and connective tissue.
• Odontoblasts line the pulp chamber and produce dentin. Odontoblasts continuously produce dentin as the patient ages, which narrows the pulp cavity.
• Pulp is encased in a hard shell.
• Pulpitis occurs when the pulp is exposed to irritants like bacteria (through fractures, diseases, attrition, abrasions, or caries) or from thermal sources such as scaling or polishing teeth.
• Pulpitis is often caused by trauma or fractures and can lead to pulp necrosis
• Trauma and swelling of the pulp (pulpitis) can cause red blood cells/hemoglobin to move into the dentin tubules, resulting in tooth discoloration (pink).
• As hemoglobin breaks down, the tooth's color may turn to purple. If the pulp dies, the tooth turns grey/brown, occasionally yellow/brown.
• If the entire crown is discolored it is likely (90% of the time) that the pulp is completely devitalized (non-vital).
• Inflammatory swelling within the pulp results in compressive strangulation of the blood vessels, leading to hemolysis.
• Once bacteria enters the pulp chamber, it moves out through the apical delta into the surrounding alveolar bone, leading to an abscess.
• Pulp death stops the odontoblast's blood supply, stopping dentin production. This is why the tooth never returns to its original color, and the pulp chamber does not continue to narrow.
• Not all non-vital teeth will have radiographic changes.

Basics of Endodontic Procedures

• Gain access to the canal by burring or drilling.
• Remove diseased pulp.
• File and clean the canal.
• Disinfect the canal.
• Fill the canal with gutta percha.
• Fill the access site and restore the tooth.
• Vital Pulpotomy, performed within 48 hours of the fracture in a mature tooth, treats recent fractures, removing exposed and contaminated pulp. Disinfection of the remaining pulp and the resurfacing access point follows. Vital pulpotomy is not recommended in cats.
• Direct Pulp Capping involves purposeful crown reduction, and includes procedures where some of the pulp is removed, allowing the tooth to continue to mature, and is similar to vital pulpotomy, but is performed following iatrogenic pulp exposure (crown reduction on spearing [linguoverted] canines) in which the pulp does not require disinfection before resurfacing, as it has already been sterilized.
• Indirect Pulp Capping, a restorative procedure, treats caries when caries is 0.5mm close to the pulp, applying filler to protect the pulp.
• Root canal therapy (pulpectomy) involves the removal of the entire pulp.
• Root Canal Therapy (RCT) can be performed on any non-vital tooth or tooth with pulp exposure, however, a few other factors should be considered, the tooth should be periodontally healthy (minimal to no attachment loss, bone loss or gingival recession) and the tooth should be expected to remain healthy long term

Some Endodontic Equipment

• Cutting burrs
• Barbed broaches are soft iron wires with flared barbs, useful for removing intact pulp.
• Files are used to clean the canal and remove dead/infected tissues. Files come in multiple sizes and color-coded diameters, and should remain sharp. Files can be marked with an endodontic stop to prevent them from being used beyond the apical working depth of the tooth.
• Irrigation needles
• Pluggers, blunt tipped probes, are used to vertically compact Gutta Percha and come in various lengths and diameters.
• Finishing discs

Materials

• Calcium hydroxide stimulates the formation of a dental bridge.
• Gutta percha is a radiopaque material used to fill pulp canals.
• Sodium hypochlorite is a disinfectant for canals.
• Crowns can be composites (plastic) or metal.
• Radiographs are taken at each stage of endodontic procedures, which are usually monitored via radiograph 6 months post-op, then annually for treatment failure. RCTs are 95% successful.

Endodontics focuses on treating the dental pulp to preserve tooth integrity, often involving pulp removal and tooth restoration. Exodontics involves complete tooth extraction, sometimes requiring surgical bone removal. Pulpitis, inflammation of the pulp, can be caused by bacteria or trauma.