Twelve studies were included in the review (n=223, range 10 to 46): six randomised controlled trials, four controlled clinical trials, one case series and one described as a prospective clinical trial. Five studies had a split-mouth design. Risk of bias was considered low for six studies, moderate for three and high for three.
Weighted mean changes at the approximal aspect of the neighbouring teeth showed a mean loss of 0.64mm (95% CI -0.70 to -0.59; three studies, n=45). Mid-buccal loss was 1.67mm (95% CI -1.91 to -1.43; six studies, n=84). Change at the mid-lingual aspect was -2.03mm (95% CI -2.49 to -1.56; two studies, n=32). Socket fill-in height (measured relative to the original socket floor) was on average 2.57mm (95% CI 2.45 to 2.71; three studies, n=39). Reduction in width of alveolar ridges was 3.87mm (95% CI -4.06 to -1.56; five studies, n=71). Mean crestal height change (assessed on radiographs) was 1.53mm (95% CI -1.70 to -1.37; four studies, n=111). Further results for radiographical outcomes were reported.