Immediate Versus Delayed Loading of Mandibular Implant- Retained Overdentures: A 12-Year Follow-up of a Randomized...

To evaluate the clinical and radiographic outcomes of two implants placed using either an immediate loading (IL) or delayed loading (DL) protocol to support a nonsplinted, Locator-retained mandibular overdenture.

Twelve eligible patients were enrolled, with six in the IL group and six in the DL group. Clinical and standardized radiographic examinations were conducted to assess implant survival and peri-implant hard and soft tissue health. Patientreported outcomes (PROs) were collected, and the incidence and nature of prosthetic complications were documented.

The data for the 5-year follow-up of the randomized controlled trial (RCT) were reported in a previous publication. No statistically significant difference in radiographic bone levels (ΔRBL) was observed between IL and DL groups during the 5- to 12-year or 0- to 12-year intervals. One implant was lost in the DL group in the 5- to 12-year period, resulting in a cumulative implant survival rate (CSR) of 96% for DL and 100% for IL at 12 years. At the 12-year follow-up, no significant differences were observed between IL and DL groups with respect to clinical outcomes such as probing pocket depth (PPD), plaque score (PS), keratinized tissue width (KTW), and apical migration of the free gingival margin (GM). PROs related to patient comfort and satisfaction were similar in the IL and DL groups. Major prosthetic complications occurred in 50% of patients, while 92% experienced at least one minor prosthetic issue. A temporal trend of increased radiographic bone loss, decreased KTW, and increased apical migration of the GM from baseline to 12 years was noted in both the IL and DL groups.

Both IL and DL protocols demonstrated comparable long-term patient comfort, patient satisfaction, and clinical and radiographic performance when applied to two nonsplinted, Locator-retained implants supporting a mandibular overdenture. Within the limitations of the present investigation, IL may represent a reliable and potentially favorable treatment approach for mandibular overdentures in appropriately selected cases. Significant prosthetic complications were noted in both groups, which highlights the importance of regular recall and prosthetic maintenance for long-term success.