North Texas Dentistry Volume 5 Issue 6 - Page 18

SMILES SPOTLIGHT in the Endodontic Retreatment Procedure Conservative access to the pulp chamber through metal, porcelain, zirconia and porcelain-fused-to-metal crowns is possible with the use of an endodontic microscope that enables advanced magnification and illumination. Metal posts, cast posts, fiber posts, plastic or metal carriers and separated instruments are removed using ultrasonic and other micro-endodontic instruments. Ledges and transportations from the previous treatment are overcome to enable disinfection of the critical apical third of the canals. All endodontic filling materials are removed and the canals are debrided and disinfected using ultrasonic irrigation techniques. They are then obturated with gutta percha using warm vertical condensation. The access cavity is restored with composite and a new crown if necessary. Radiographic evidence of healing is typically observed within 6 to 12 months of endodontic retreatment. LEADERS IN NORTH TEXAS DENTISTRY CREATING UNFORGETTABLE SMILES Endodontic Retreatment and Apicoectomy The success of endodontic treatment can vary from 86-97%. However, for various reasons, endodontically treated teeth can get reinfected and can become painful or diseased months or even years after treatment. The leading causes of reinfection of endodontically treated teeth include: 1. Coronal microleakage – delayed placement of restoration and crown; teeth not restored with crowns; open margins on crowns causing salivary contamination of the root canals. 2. Complicated canal anatomy that went undetected in the initial treatment. 3. New decay or fracture exposing the root canal filling material. 4. Fracture of the root that causes bacterial penetration into the canals. Treatment Options Whenever possible, it is best to save one’s natural teeth. The success rate of endodontic retreatment ranges from 77-89%, because of which there is substantial possibility that one may be able to save one’s teeth from extraction even if the initial endodontic treatment fails. The prognosis for retreatment increases exponentially when there is an obvious cause for the failure of the initial treatment such as the presence of missed canals or obturation that is short of the apex. Endodontic-periodontic lesions in endodontically treated teeth that may be commonly misdiagnosed as vertical root fractures can also be successfully retreated. Advances in technology are constantly changing the way root canal treatment is performed. When using the latest technologies for diagnosis and treatment such as cone beam computed tomography and microscopes, high success rates for endodontic treatments and retreatments are achievable. 18 NORTH TEXAS DENTISTRY | Pre-op x-ray: Two buccal sinus tracts leading to the mesial and distal root apices of tooth #30, traced with gutta percha cones Immediate Post-op x-ray after retreatment. Pre-op x-ray: Evidence of missed canals after initial endodontic treatment in tooth #18 Pre-op x-ray: Evidence of missed canals after initial endodontic treatment in tooth #18 6 month Post-op x-ray: Bone regeneration and healing observed Post-op x-ray: C-shaped canal; Additional canals found and obturated Immediate post-op x-ray after retreatment 6-month post-op x-ray: Bone regeneration and healing observed