Root-Retained Overdentures: Preserving Roots Is Valuable, but There Is One Important Risk!

Sometimes teeth that are not good candidates for a fixed or partial denture, because of reduced bone support or an unfavorable crown-to-root ratio, can still serve as abutments for an overdenture.

Preserving these roots, especially mandibular canines, helps reduce bone resorption, increases denture stability and maintains proprioception, and it can increase patient satisfaction.

But what is the main concern with this treatment?

A systematic review published in 2024 examined the results of 11 randomized clinical trials on overdentures supported by natural teeth (Root-Retained Overdentures).

Root caries was the most frequently reported complication. The authors emphasize that these carious lesions may progress even in a short time and lead to the loss of the abutment tooth.

A few important and practical points from the article:

• Cast coping: The article refers to an earlier systematic review that reported a loss rate of less than 2 percent per year for abutment teeth with metal copings. However, this figure concerns tooth survival and does not mean that metal copings have been shown to reduce caries.
• Caries prevention: In the studies reviewed, the use of fluoride compounds and chlorhexidine-fluoride compounds helped reduce root caries. Chlorhexidine compounds have also been reported to be effective in controlling plaque and improving gingival condition.
• Choice of restorative material: There is still not enough evidence to determine which material is best for sealing the root canal orifice of abutment teeth. In some studies, amalgam restorations needed repair more often.
• Denture maintenance: Some overdentures need repair or replacement within the first five years. Therefore, caring for the denture itself is as important as examining the abutment teeth.
• Periodic examinations: The authors emphasize meticulous oral hygiene and regular visits, and recommend at least one examination per year.

Clinical Takeaway

The overdenture supported by natural teeth remains a valuable treatment option, especially for patients in whom preserving even a few roots can help maintain bone and denture stability.

But preserving roots alone does not guarantee treatment success. Root caries is one of the most important threats to the survival of abutment teeth, and its prevention should be taken seriously from the very start of treatment.

Of course, the evidence in this review has limitations; 9 of the 11 studies had a high risk of bias, and a meta-analysis was not possible.