A root canal is precise work in a very small space. A canal can be narrower than a pencil lead, and some teeth have more canals than the textbook drawing shows. Magnification helps the endodontist see what is there.
The canal that hides
Upper molars often have a second canal in one of their roots, called MB2. Its opening can be tiny and tucked under a ledge of tooth.
In a clinical study of 312 upper molars treated by endodontists:
- with a microscope, the MB2 canal was found in 57 percent of teeth
- with dental loupes, 55 percent
- with no magnification, 18 percent
For upper first molars alone, the microscope group found it in 71 percent of teeth, compared with 17 percent without magnification. A lab study found the same pattern: magnification helped clinicians not only find the opening but follow the canal along its length.
Why it matters
Any canal left untreated can hold bacteria. Researchers at the University of Pennsylvania reviewed 1,397 3D scans of teeth that already had root canals. About 23 percent of the treated premolars and molars had a missed canal, and 40 percent of upper molars did. Teeth with a missed canal were 4.4 times more likely to have infection at the root tip.
What you will notice
Not much. You lie back in the chair, the microscope sits above you, and Dr. Hirose works through it. What you may notice is that he can show you pictures of what he saw, such as a crack line or an extra canal, so you understand your tooth and your options.
Beyond the first root canal
Magnification matters even more in surgery. A meta-analysis from Penn’s endodontics department compared older root-end surgery with modern microsurgery and found success rates of 59 percent and 94 percent. Read more about microsurgery and retreatment.
If your dentist has recommended a root canal, call the Mountain View or Saratoga office. Dr. Hirose will look at your tooth under the microscope and talk you through what he finds.