The quality of evidence is downgraded by study limitations (lack of/unclear allocation concealment), by indirectness (in the majority of the included trials, the inclusion criteria were strict and only patients known to be ideal candidates for implant treatment were recruited, and in general operators were highly experienced), and by imprecise results (wide confidence intervals).
A Cochrane review [Abstract] 1 included 26 studies with a total of 1 217 patients and 2 120 implants. Fifteen trials compared immediate versus conventional loading, 3 early versus conventional loading, 6 immediate versus early loading, and 2 occlusally versus non-occlusally loaded implants. Immediate loading was defined as an implant put in function within 1 week after its placement; early loading as those implants put in function between 1 week and 2 months; and conventional loading as those implants loaded after 2 months.
In nine of the included studies there were no prosthetic failures within the first year, with no implant failures in 7 studies and the mean rate of implant failure in all 26 trials was a low 2.5%. Comparing immediate with conventional loading there was no evidence of a difference in either prosthesis failure (RR 1.90, 95% CI 0.67 to 5.34; 8 studies, n=381) or implant failure (RR 1.50, 95% CI 0.60 to 3.77; 10 studies, n=421) in the first year, but there was some evidence of a small reduction in bone loss favouring immediate loading (MD -0.10 mm, 95% CI -0.20 to -0.01; 9 studies, n=293), with some heterogeneity (I² = 44%). However, this very small difference may not be clinically important. There was insufficient evidence to determine whether or not there was a clinically important difference in prosthesis failure, implant failure or bone loss in early loading compared with conventional loading; in immediate loading compared with early loading; or in occlusal loading compared with with non-occlusal loading.
Primary/Secondary Keywords