Y2 L2 Overview of root canal treatment

Question 1

What is apical periodontitis?

Answer 1

Polymicrobial infection of the pulp by selective oral micro-organisms that have breached the enamel and dentine, overwhelmed the immune response in the pulp and settled in the remaining necrotic tissue.
Aim of endo treatment is to prevent or cure apical periodontitis by control of infection.

Question 2

What is the AAE consensus for recommended apical diagnostic terminology?

Answer 2

• Normal apical tissues
• Apical periodontitis (symptomatic or asymptomatic)
• Apical abscess (chronic or acute)
• Condensing osteitis

Question 3

When are systemic antibiotic indicated in endodontics?

Answer 3

• Acute apical abscess in medically compromised pts
• Acute apical abscess with systemic involvement (fluctuant swelling, pyrexia, lymph node involvement, trismsu)
• Progressive infection (rapid onset of severe infection in under 24 hours)
• Replantation of avulsed permanent teeth
• Soft tissue trauma requiring treatment (e.g. debridement, sutures)

Abx are rarely indicated in endo. Most endo infections are confined within the tooth and can be successfully managed with local interventions.

Question 4

What are the stages for RCT.

Answer 4

1) Diagnose
2) Assess restorability, can the tooth be restored after RCT? Need a restoration that allows a rubber dam to be placed and maintain a good seal
3) Access pulp chamber and root canals
4) Pulpectomy and canal preparation (shaping and cleaning)
5) Canal filling
6) Tooth restoration
7) Recall and review

Question 5

What are the possible outcomes of RCT?

Answer 5

• Health
• Persisting/emerging disease

Question 6

What are the possible reasons for peristent apical periodontitis following RCT?

Answer 6

• Poor quality technical procedures:
• Lack of rubber dam
• Inability to instrument all of root canal
• Poor disinfection
• Poor root filling
• Missed Canals
• Complex anatomy
• Coronal leakage
• Intra-radicular infection, extra-radicular infection, true cysts, foreign body reaction

Question 7

What are the 3 possible outcomes of endodontic treatment according to the ESE?

Answer 7

• Favourable outcome: absence of pain, swelling or other symptoms, no sinus tract, no loss of function, radiological evidence of normal PDL
• Uncertain outcome: lesion the same size or only diminished in size (less than 4 years after treatment)
• Unfavourable outcome: lesion has remained the same size or only slightly smaller after 4 years, signs/symptoms of infection or root resorption

Question 8

What is the estimated treatment success rate for primary root canal treatment?

Answer 8

75-85%

Question 9

What is the estimated treatment success rate for secondary root canal treatment?

Answer 9

77%

Question 10

What 3 major factors affect the treatment outcome of secondary RCT?

Answer 10

• Presence and size of pre-op periapical lesion
• Apical extent of final root filling (how close filling is to end of canal)
• Quality of coronal restoration

Question 11

What 4 major factors improve treatment outcome of primary RCT?

Answer 11

• Pre-op abscence of periapical radiolucency
• Root filling extending to 2mm within the apex
• Satisfactory coronal restoration
• Root filling with no voids

Question 12

What were the 11 prognostic factors found to improve periapical healing in a 2011 study?

Answer 12

Question 13

What is the difference between success vs survival rate?

Answer 13

Important to recognise the difference.
Tooth survival = tooth still in the mouth and functional.
The fourth-year tooth survival following primary or secondary RCT is 95% (Ng et al 2011)