Introduction to Endodontics

• Endodontics is the branch of dentistry concerned with the morphology, physiology, and pathology of the dental pulp and periradicular tissues.
• Its study and practice encompass the prevention, diagnosis, and treatment of diseases and injuries of these tissues.

Objectives of Endodontic Treatment

• To eliminate pulpal and periradicular disease.
• To promote periradicular tissue healing.
• To prevent future infection.

Diagnostic Procedures

• Patient history includes medical and dental history to identify potential contraindications, allergies, and systemic conditions affecting treatment.
• Clinical examination assesses the tooth's condition, including caries, restorations, fractures, and periodontal status.
• Pulp testing evaluates the pulp's response to stimuli like cold, heat, and electric pulp testing to determine its vitality.
• Radiographic examination uses X-rays to visualize the tooth's root, surrounding bone, and any periapical pathosis; CBCT may be indicated.

Pulpal and Periradicular Diagnoses

• Normal pulp is a clinical diagnostic category in which the pulp is symptom-free and normally responsive to pulp testing.
• Reversible pulpitis is inflammation of the pulp; the pulp is capable of returning to a healthy state if the irritant is removed.
• Irreversible pulpitis is inflammation of the pulp that is incapable of healing and would require root canal therapy or extraction.
• Pulp necrosis is the death of the dental pulp.
• Previously treated means the tooth has been endodontically treated, and the canals are obturated with filling materials.
• Previously initiated therapy means the tooth has been previously treated by partial endodontic therapy, such as a pulpotomy or pulpectomy.
• Normal apical tissues are teeth with normal periradicular tissues that are not sensitive to percussion or palpation testing and have a normal lamina dura and periodontal ligament space.
• Symptomatic apical periodontitis is inflammation, usually of the apical periodontium, producing clinical symptoms including a painful response to biting and/or percussion or palpation.
• Asymptomatic apical periodontitis involves inflammation and destruction of the apical periodontium that is of pulpal origin, appears as an apical radiolucent area, and does not produce clinical symptoms.
• Acute apical abscess is an inflammatory reaction to pulpal infection and necrosis characterized by rapid onset, spontaneous pain, tenderness of the tooth to pressure, pus formation, and swelling of associated tissues.
• Chronic apical abscess is an inflammatory reaction to pulpal infection and necrosis characterized by gradual onset, little or no discomfort, and the intermittent discharge of pus through an associated sinus tract.
• Condensing osteitis is a diffuse radiopaque lesion representing a localized bony reaction to a low-grade inflammatory stimulus, usually seen at the apex of a tooth.

Root Canal Treatment Procedures

• Access cavity preparation involves creating an opening in the tooth to allow access to the root canal system.
• Working length determination involves measuring the length of the root canal to ensure proper cleaning and shaping.
• Cleaning and shaping involve removing infected tissue and debris from the root canal system and shaping the canals for obturation.
• Irrigation uses irrigants like sodium hypochlorite to disinfect the root canal system.
• Obturation involves filling the root canal system with a biocompatible material, usually gutta-percha, to seal it off and prevent reinfection.

Obturation Techniques

• Cold lateral compaction involves condensing gutta-percha cones against the canal walls using spreaders and accessory cones.
• Warm vertical compaction involves softening gutta-percha with heat and compacting it vertically to fill the canal.
• Carrier-based obturation involves using a plastic or metal carrier coated with gutta-percha to fill the canal.
• Bioceramic sealers involve filling the canal with a bioactive cement.

Endodontic Instruments

• Files are used for cleaning and shaping root canals, including K-files, Hedstrom files, and rotary files.
• Spreaders and Pluggers are used for lateral and vertical compaction of gutta-percha, respectively.
• Gates Glidden drills and Peeso reamers are used for coronal flaring and removing gutta-percha during retreatment.
• Irrigation needles are used to deliver irrigants into the root canal system.

Materials Used in Endodontics

• Gutta-percha is a natural rubber material used as a core filling material in root canal obturation.
• Sealers are used to fill the space between the gutta-percha and the canal walls; examples include zinc oxide eugenol-based, resin-based, and bioceramic sealers.
• Irrigants are used to disinfect the root canal system; common irrigants include sodium hypochlorite, EDTA, and chlorhexidine.
• Calcium hydroxide is used as an intracanal medicament for its antibacterial properties.
• Mineral Trioxide Aggregate (MTA) is a bioactive cement used for various endodontic procedures, including apexification, perforation repair, and root-end filling.

Endodontic Failures

• Persistent infection is the failure to eliminate bacteria from the root canal system.
• Coronal leakage involves leakage of bacteria into the root canal system through a poorly sealed restoration.
• Missed canals are the failure to identify and treat all canals in the tooth.
• Root perforation involves creating an artificial opening in the root structure.
• Separated instruments involve the breakage of an endodontic instrument inside the root canal.

Endodontic Retreatment

• Removal of existing root canal filling materials.
• Re-cleaning and shaping of the root canal system.
• Identification and treatment of missed canals.
• Repair of perforations.
• Obturation of the root canal system.

Endodontic Surgery

• Apicoectomy is the surgical removal of the root tip.
• Root-end filling involves the placement of a filling material at the resected root end.
• Periradicular curettage involves the removal of infected tissue around the root apex.
• Hemisection/root amputation involves the removal of a root or part of a tooth.

Apexification

• A method of inducing a calcified barrier in a root with an open apex or continued apical development of an incompletely formed root in teeth with necrotic pulps.
• Calcium hydroxide or MTA are commonly used.

Apexogenesis

• A vital pulp therapy procedure performed to encourage continued physiological root development and apex closure.
• Typically done in young permanent teeth with immature roots.

Traumatic Injuries

• Crown infractions/fractures: Cracks or fractures in the enamel or dentin.
• Root fractures: Fractures in the root structure.
• Luxation injuries: Injuries to the tooth's supporting structures, such as concussion, subluxation, extrusion, and intrusion.
• Avulsion: Complete displacement of the tooth from its socket.

Management of Traumatic Injuries

• Prompt diagnosis and treatment are crucial for a favorable prognosis.
• Treatment may include repositioning, splinting, root canal treatment, apexification, or extraction.
• Avulsed teeth should be replanted as soon as possible after rinsing with saline or milk, if extra-oral time is less than 60 minutes.

Endodontic Considerations for Special Populations

• Pediatric patients: Considerations for root development, apexification, and pulp therapy.
• Geriatric patients: Considerations for age-related changes in pulp and root structure.
• Medically compromised patients: Modifications to treatment based on the patient's medical condition and medications.

Endodontics focuses on the dental pulp and periradicular tissues. It involves the diagnosis, prevention, and treatment of their diseases and injuries. Endodontic treatment aims to eliminate disease, promote healing, and prevent future infection through procedures like pulp testing and radiographic examination.