This Randomized clinical study was conducted to compare between two-implant versus single implant-retained mandibular overdenture regarding swallowing dynamic using The Test of Mastication and Swallowing Solids (TOMASS) and the Timed Water Swallow Test (TWST)

There are lack of studies comparing single and two implant-retained mandibular overdentures regarding swallowing dynamic. This Randomized clinical study aimed to compare the effect of two treatment modalities of mandibular implant over denture on the swallowing dynamic.

8 completely edentulous patients were selected from the Out-Patient Clinic of Prosthodontics' Department, Faculty of Dentistry, Mansoura University seeking prosthetic rehabilitation. All patients were randomly distributed into two equal groups; Group I (Patients received two-implant mandibular overdenture with locator attachment) and Group II ( Patients received single implant mandibular overdenture with locator attachment) All subjects received a newly carefully constructed complete dentures and then the lower dentures were changed into mandibular implant retained overdentures using locator attachments by placing two implants on the mandibular canine regions for group I and single midline implant for group II.

Swallowing dynamic was evaluated after 3 months of complete denture insertion for both groups. After mandibular overdenture insertion swallowing dynamic was evaluated 2 weeks after insertion and three months after overdenture insertion for both groups.

Inclusion Criteria:

• Free from any systemic disease.
• Free from any medical or surgical conditions that cause dysphagia (swallowing problems).
• A sufficient residual alveolar bone quantity (height and width). This was verified by a CT scan using cone-beam computed tomography for each patient.
• All patients had sufficient bone either D2 or D3 by measuring the Hounsfield unit on CBCT scan.
• Residual ridges are covered by firm healthy mucosa.
• Class I maxilla-mandibular relationship.
• sufficient inter-arch space and restorative space for locator retained mandibular overdenture.

Exclusion Criteria:

• Patient with absolute contraindications for implant placement such as active cancer, immunosuppression, bleeding issues, and metabolic diseases that directly affect the bone such as osteoporosis, and hyperparathyroidism.
• Patients with relative contraindication: history of para functional habits such as bruxism, clenching, and bad habits such as smoking and alcoholism, uncontrolled diabetic patients.
• Patients with local contraindications for implant placement due to localized bone defects.
• Non-cooperative patients who don't follow instructions during and after the operation.