DOING ROOT CANAL treatment on a premolar may seem very simple, but, believe it or not, mandibular premolars have a high failure rate and a high rate of flare-ups.
Mandibular first premolars have a small lingual cusp, so the lingual canal, if there is one, tends to be at a sharp angle lingually. What you need to do is to bend the file apically to get into this extra canal. A single canal is present in 74–80 percent of mandibular first premolars, two canals are present in 18–25 percent (Figures 1 and 2), and three canals in 0.5–5 percent.
Mandibular second premolars are more predictable. A single canal is present in 85–98 percent of them, and two canals are present in 1–15 percent of them. Three canals are very rare. Lastly, it has been shown that African Americans tend to have multiple canals three times more frequently than Caucasians.
January - March 2012