ABSTRACT
BACKGROUND: A 71-year-old female presented with a left submandibular space abscess. This was found to be due to large accumulations of calculus on the lingual flanges of her lower denture ulcerating the floor of the mouth. She had not taken the prosthesis out since it was provided as an immediate denture after extractions 54 years previously. At presentation she could not take her denture out as the calculus locked the denture under lingual undercuts. The denture was sectioned in the midline to remove it and the submandibular abscess was drained via a neck incision. FINDINGS: Prior to removal the denture was remarkably stable and she had enjoyed a long period of problem free denture wearing and had had exceptional value from it. There was also surprisingly little mandibular alveolar bone resorption. CONCLUSION: The case demonstrates what may happen if a lower denture is not taken out for over half a century. The calculus on the lingual flanges provided both stability and retention for the denture, and it appeared to have protected the ridge from resorption. While the calculus may have provided some surprising benefits to her lower denture it ultimately led to a serious infection.