[Table/Fig-11]:

Summary of incidence of three distal canals in mandibular first molar.

Investigator	Year	Teeth	Method	Incidence (%)
Gulabivala et al., [3]	2001	139	Vitro	0.7
Gulabivala et al., [5]	2002	118	Vitro	1.6
Sert et al., [6]	2004	20	Vitro	1.0
Ahmed et al., [7]	2007	100	Vitro	3.0