JOVD 2008: Endodontic Tx of a Non-Vital permanent Tooth with Open Root Apex Using MTA

Question 1

Authors?

Answer 1

S. Juriga

S. Manfra

Question 2

Difference between Apexogenesis and Apexification?

Goal of apexification?

Answer 2

• Apexogenesis: Physiological formation of the apex of a vital tooth
• Apexification (APN): Procedure to promote apical closure of a nonvital tooth
  
  • Goal: to provide a hard tissue barrier that will provide an apical stop for effective obturation of the canal allowing the patient to retain the tooth

Question 3

What was the initial patient condition in this case report?

What were the steps of the APN procedure in this case report?

Answer 3

Young cat with traumatic immature permanent 104 with pulp necrosis and chronic periradicular periodontitis

Procedure: 2 visits-tx

• 1st visit:
  
  • Determined WL (15 K-File)
  • Gentle circumferential filing of canal (C-prep); flush NaOCl 2.5 % warm between files (blunt tip needle, 1.5mm short of apex, in-and-out motion)
  • Canal soak NaOCl 5% x 5 min; 17% EDTA should have been used to remove smear layer; rinse sterile water
  • Plugger selection (1.5mm short of apex)
  • 5mm MTA placement (1mm increment with plugger; x-ray confirm); ppt moistened place over MTA then removed
  • Temporary restoration with GI cement
• 2nd visit (4 hours or more after MTA; here 4 days)
  
  • Remove coronal restoration with round bur
  • Flush canal 2.5% NaOCl
  • Determined WL (15 K-file)
  • Flush sterile saline; dried with ppt
  • Obturation: Thermoplasticized GP vertial compaction
  • Coronal restoration

Question 4

At what level should the MTA plug be placed?

Question 5

Can this procedure be done as a 1-visit Tx?

Answer 5

Yes

Can do a 1 visit technique by adding a barrier of self curing GI over the top of the MTA and then obturating immediately

Question 6

What could have been done differently to improve the procedure?

Answer 6

• Warm (37C) irrigant
• Removal of smeal layer with 17% EDTA
• Placement of MTA with Ultrasonic (should place resorbable barrier collagen foam to prevent extrusion of MTA)

Question 7

What was the follow-up?

Answer 7

Radiographic reevaluation 6 months post-tx

Question 8

Disadvantages of Calcium hydroxide?

Answer 8

• unpredictability of apical closure (success rates 74-100%)
• variability in treatment time (5-20 months in human)
• number of appointments/patient (owner) compliance/difficulty in patient follow-up
• weakened root dentin with long-term calcium hydroxide
• delayed treatment/leakage of temporary restoration/recurrence of infection

Question 9

Advantages of MTA?

Answer 9

• biocompatible
• non-cytotoxic
• set in the presence of moisture or blood (hydrophylic)
• bacteriocidal effects
• adequate seal of root canal (prevent bact. leakage)
• allows undifferentiated cells to transform into fibroblast, cementoblast and osteoblast to regenerate the original periradicular tissues (cementum and bone)

Question 10

What is the composition of MTA?

Answer 10

tricalcium silicate, tricalcium aluminate, tricalcium oxide, and silicate oxide

Question 11

What irrigation agents can be used?

Answer 11

Ideal agent: debride; disinfect with sustained antimicrobial effect; lubricant, dissolve tissues left in canal, non-toxic, non-antigenic, non-carcinogenic

Use endo needle 1-2mm from apex; passive pressure

• NaOCl (0.5-5.25%): best antibacterial and dissolve tissues; 2.5% large and frequent flush; do not dissolved smear layer so need EDTA flush
• Chlorhexidine gluconate (0.2-2%): Less effective disinfectant and no dissolving properties but les cytotoxic than NaOCl; absorb into dentin and release for prolong effect