Reports & Studies

Prognosis for teeth with through-and-through furcations

PD Dr. Kristina Bertl, PhD MSc MBA

The optimal treatment result for periodontitis patients is for them to keep their own teeth in good condition for as long as possible. However, there are both patients and teeth with certain characteristics that make it significantly harder to actually achieve this objective!

Prognosis for teeth with through-and-through furcations

When it comes to teeth, those with multiple roots are, of course, often much more difficult to treat, especially if they present furcation defects. Why is the furcation area so challenging? In comparison to single-rooted teeth, access for mechanical cleaning of the root surface is much more difficult, the furcation entrance can often be very small/narrow, and there may also be further anatomical particularities, such as enamel projections.

A systematic review in 2016 (Nibali et al.) showed, for example, that teeth with a furcation defect are around twice as likely to have been extracted after 10–15 years of periodontal maintenance treatment. The risk of tooth loss also increases the higher the furcation defect grade; therefore, a molar with a through-and-through furcation defect (grade III) was approx. three times as likely to be lost than a molar with a grade I furcation defect.

A recently published study from Frankfurt (Eickholz 2021) specifically looked at teeth with a through-and-through furcation defect. They studied a total of 265 teeth with a through-and-through furcation defect in 160 patients; all patients had been receiving periodontal maintenance treatment for at least five years. We should take the following important points into account based on this data:

  • Teeth with a grade III furcation defect are more frequently lost than single-rooted teeth, for example, and, after approx. 10 years of periodontal maintenance treatment, we should expect approx. one third of these teeth to have been extracted. At the same time, however, this also means that two thirds of these periodontally severely compromised teeth are still in place.
  • There is a wide range of possible reasons for an extraction – from periodontal problems, through to cavities and/or prosthetic problems.
  • The following risk factors for loss have been identified for teeth with a through-and-through furcation defect: a higher level of bone loss at the start of the treatment and higher probing depths at the start of the maintenance treatment.
  • If the patient was also treated with systematic antibiotics during the active treatment phase, this also resulted in a lower rate of tooth loss for teeth with a through-and-through furcation defect. However, it must be borne in mind here that a through-and-through furcation defect should not be the only basis for an indication for systemic antibiotic treatment. The patient should always be considered as a whole and the decision to administer systemic antibiotic treatment should always be made carefully, in view of the increasing resistance to antibiotics around the world.


  1. Eickholz, P., Runschke, M., Dannewitz, B., Nickles, K., Petsos, H., Kronsteiner, D., & Pretzl, B. (2021). Long-term prognosis of teeth with class III furcation involvement. Journal of Clinical Periodontology, 48(12), 1528–1536. Nibali, L., Zavattini, A., Nagata, K., Di Iorio, A., Lin, G. H., Needleman, I., & Donos, N. (2016). Tooth loss in molars with and without furcation involvement—A systematic review and meta-analysis. Journal of Clinical Periodontology, 43, 156–166.