Which statement about overdentures is not correct?

The statement that the retained roots are covered by the denture thus protecting them from caries and periodontal diseases is not accurate in the context of overdentures. While overdentures do provide a beneficial structure for oral health, they do not inherently protect retained roots from caries or periodontal diseases. In fact, if there is inadequate oral hygiene or maintenance, the roots can still be susceptible to these conditions.

Overdentures are designed to fit over the remaining roots or natural teeth, which can provide better retention and stability compared to conventional dentures. This feature allows for better force distribution during chewing, which can result in improved masticatory efficiency. Additionally, by retaining the roots, there is stimulation to the underlying bone, which can reduce the rate of alveolar bone resorption—a significant benefit related to long-term oral health.

In contrast, the assertion regarding protection from caries and periodontal diseases suggests a misunderstanding of the risks involved. The retained roots must be cared for, as effective oral hygiene is critical to prevent such conditions. Therefore, while overdentures have many advantages, the statement regarding their protective effect on retained roots is not correct.