Comparison Between Ball and Locator Attachments in Patients Receiving Complete Mandibular Overdenture Retained by Single Midline Implant

The selected patients will be informed of the nature of the research work and informed consent will be obtained for each one of them. Only motivated patients who showed co-operation will participate in the study. Patients will be randomly divided into 2 groups.

Conventional upper and lower complete dentures will be constructed before installing the implant where the lower denture will be duplicated into a radiographic stent. CBCT (cone beam computerized tomography) with lower radiographic stent in place stabilized with the upper denture using a rubber base index, will be taken to know the available bone height &width to determine the optimum implant size.

Patients will receive single implant in symphyseal region of mandible. The surgical procedure is carried out under local anaesthesia, following premedication with 2 g amoxicillin (or 600mg of clindamycin) and 1 g paracetamol. After two rinses with 0.2% chlorhexidine gluconate, each lasting 1 min, the labial and lingual mucosa of the anterior mandible is locally infiltrated with 2.2 ml of mepivacaine 2% with 1 : 100,000 adrenalin. The surgical guide made from the duplicated mandibular complete denture is used to mark the implant site.

A crestal incision will be performed and a full-thickness mucoperiosteal flap is raised to expose the anterior mandible. Deep dissection of this flap lingually exposes the cortical plate of the mandible and any lingual concavities. Sequential drilling & implant placement will be the next step. The implant position is adjusted to the midline of the mandible and optimum labiolingual positioning and bone levelling is performed as necessary.

A healing abutment is selected to be 2mm above the mucosa. The mucosa is adjusted and sutured with interrupted sutures (3-0 silk). Postoperatively, the patient should rinse with 0.2% chlorhexidine gluconate mouthwash for 2 weeks. Immediately following implant surgery, generous relief of the existing mandibular complete denture is carried out and a tissue conditioner is applied to the undersurface of the denture. The patient leaves after the surgical operation wearing both the complete maxillary denture opposed by the tissue-conditioned mandibular complete denture. A period of 8 weeks will be allowed for healing and osseointegration.