Clinicians treating overdenture patients need to know if immediate loading and conventional loading results in similar outcomes. This study aimed to perform a systematic literature search of studies comparing immediate and conventional loading of mandibular overdentures irrespective of the number of implants and conduct a meta-analysis of implant failure and marginal bone loss (MBL). A literature search of PubMed, ScienceDirect, Ovoid, Springer, and Google Scholar databases was performed for randomized controlled trials (RCTs) comparing immediate vs conventional loading of mandibular overdentures. The primary outcome was implant failure and the secondary outcome was marginal bine loss (MBL). A descriptive analysis was performed for other outcomes. Thirteen trials were included. Only one trial compared the immediate and delayed loading of single implant-supported overdenture. Seven trials used 2 implants, 1 trial used 3 implants while 4 trials used 4 implants. Meta-analysis indicated no statistically significant difference in implant failure and MBL between immediate and conventional loading of 2- and 4-implant supported overdentures. Descriptive analysis indicated no difference in peri-implant tissue indices, implant stability, and quality of life outcomes between the 2 loading protocols. There may be no difference in implant failure and MBL with immediate loading or conventional loading of 2- and 4-implant supported mandibular overdentures. Literature review indicates that there may be no difference in peri-implant tissue indices, implant stability, and quality of life outcomes between the 2 loading protocols. The overall quality of evidence is moderate. Further, adequately powered RCTs are required to strengthen the evidence.
Keywords: dental implants; immediate loading; overdentures; rehabilitation.