Table 3 Root code, number and percentage of root canal morphology in the mesial root of double rooted mandibular molars—canals of severely complex configurations (5 digits and more). All root canal configurations in this table are unclassifiable via Vertucci’s classification.

5 digits complex configurations

 Root code

M^{2–3–2–3–2}

M^{1–2–3–2–1}

M^{2–3–2–1–2}

M^{3–4–5–3–1}

M^{2–3–4–3–2}

M^{2–3–2–1–3}

M^{2–3–2–1–2}

 Number & percentage

1 (1.04%)

2 (2.08%)

1 (1.04%)

1 (1.04%)

1 (1.04%)

1 (1.04%)

1 (1.04%)

 Total

8 (8.33%)

More than 5 digits complex configurations

 Root code

M^{2–3–2–1–2–1}

M^{2–3–2–1–3–2}

M^{1–2–3–2–3–2}

M^{3–1–2–1–2–1}

M^{3–2–3–2–3–2–3–2}

M^{2–3–4–2–1–2–3}

 Number & percentage

1 (1.04%)

1 (1.04%)

1 (1.04%)

1 (1.04%)

1 (1.04%)

1 (1.04%)

 Total

6 (6.25%)