A Short Case Study: How Often Do You Look for the MB2?

Rico D. Short, DMD


A patient came in with pain on tooth No. 14. The radiograph appeared to have a nice fill from previous endodontic treatment. Tooth No. 14 was percussion- and biting-sensitive. The diagnosis was previous treatment with acute apical periodontitis.

Access revealed that Dentsply Sirona’s Thermafil had been used. I removed it all and located a second mesial buccal (MB2). Next, I used ultrasonics to remove the post in the palatal root. I like the Enac System by Osada. The tips are really inexpensive—about $18 versus about $100 with other units. Calcium hydroxide was placed for 2 weeks.

Figure 2. The previous root canal was disassembled, and calcium hydroxide was placed.

Figure 3. Treatment was completed with warm vertical condensation with 2 independent exits for the mesial buccal and the second mesial buccal.

Figure 4. This inversion view shows the completion of retreatment of tooth No. 14.

The patient returned asymptomatic, and the case was completed with warm vertical condensation and Kerr EWT sealer. The MB2 had an independent exit.

Kulid and Peters show an MB2 in the upper first molar at about 95%. According to Wolcott and Ishley et al, the MB2 is usually independent about 60% of the time. The added advantage of magnification and illumination provided by the surgical operating microscope enhances the location of the MB2 in the maxillary first, report Baldassari-Cruz, Lilly, and Rivera. The upper first molar is the most retreated tooth in the mouth because of the MB2.

See you at ADA 2017 in Atlanta. Come see my lecture on Friday, October 20.

Dr. Short attended the Medical College of Georgia (MCG) School of Dentistry to attain a DMD degree in 1999. In 2002, he earned his postdoctorate degree in endodontics from Nova Southeastern University and then became a Diplomate of the American Board of Endodontics in 2009. Dr. Short is an expert consultant in endodontics to the Georgia Board of Dentistry and assistant clinical professor at the Dental College of Georgia in Augusta. He is endorsed by the American Association of Endodontists speakers bureau. His private practice, Apex Endodontics PC, is located in Smryna, Ga. Dr. Short also has authored a book, Getting to the Root of Your Problem: 365 Days of Inspirational Thinking. He can be reached at dr.short@yahoo.com.

Related Articles

A Root Canal Trifecta

What to Do When the Pin Drops In

Microcracks, Endodontics, and Bioceramics