Table 1 Prognosis based on various intra-operative factors

Intra-operative

Apical patency

Previously untreated/Primary RCT

Negotiable

Good

Inability to achieve technical patency (debris/complex anatomy)

Questionable (For every 1 mm short from the apical terminus - prognosis changes from questionable to poor)

Retreatment

Able to remove a significant amount of the existing root filling material

Questionable

Inability to remove filling material

Non-Salvageable

Poor

Peri-cervical dentine (PCD)

Access cavity preparation and remaining coronal walls

Adequate preservation of PCD with UCAC or CAC forms

Good

Good

CAC preparations needing some removal of tooth structure, adequate coronal residual walls

Fair

TAC needing greater removal of tooth structure, adequate coronal residual walls

Questionable

TAC needing greater removal of tooth structure, compromised coronal residual walls

Compromised

Poor

Obturation

Length of root canal obturation

Root filling extending 0-<1 mm short of radiographic apex

Good

Good

Root fillings ending at the radiographic apex (or 1-2 mm short)

Fair

Root fillings with biomimetic sealers ending beyond the radiographic apex (overfilling)

Fair

Good

Root fillings with traditional sealers ending beyond the radiographic apex (overfilling)

Questionable

Root filling ending >2 mm short of radiographic apex (underfilling)

Compromised

Poor

Density of root canal obturation

No void present in the root canal obturation

Good

Good

Void(s) limited to coronal third

Fair

With void(s) within the mid/apical third

Compromised

Poor

Taper of root canal obturation

Consistently tapered from coronal part to apex

Good

Good

Inadequate taper

Fair

Inconsistent or irregular taper (over or under shaped)

Compromised

Poor

Intra-appointment pain and swelling

Asymptomatic between appointments (no flare ups)

Good

Good

Symptomatic between appointments (flare ups)

Fair