Abstract: We included 12 trials, which recruited 389 participants. No studies assessed the primary outcome tooth loss. Ten trials compared FMS and control; three of these were assessed as being at high risk of bias, three as unclear risk and four as low risk. There was no evidence for a benefit for FMS over the control for change in probing pocket depth (PPD), gain in probing attachment (i.e. clinical attachment level; CAL) or bleeding on probing (BOP). The difference in changes between FMS and control for whole mouth PPD at three to four months was 0.01 mm higher (95% CI -0.17 to 0.19, three trials, 82 participants). There was no evidence of heterogeneity. The difference in changes for CAL was 0.02 mm lower (95% CI -0.26 to 0.22, three trials, 82 participants), and the difference in change in BOP was 2.86 per cent of sites lower (95% CI -7.65 to 1.93, four trials, 120 participants). We included six trials in the meta-analyses comparing FMD and control, with two trials assessed as being at high risk of bias, one as low and three as unclear. The analyses did not indicate a benefit for FMD over the control for PPD, CAL or BOP. The difference in changes for whole-mouth PPD between FMD and control at three to four months was 0.13 mm higher (95% CI -0.09 to 0.34, two trials, 44 participants). There was no evidence of heterogeneity. The difference in changes for CAL was 0.04mm higher (95% CI -0.25 to 0.33, two trials, 44 participants) and the difference in change in BOP being 12.59 higher for FMD (95% CI -8.58 to 33.77, three trials, 68 participants). Three trials were included in the analyses comparing FMS and FMD. The mean difference in PPD change at three to four months was 0.11 mm lower (-0.34 to 0.12, two trials, 45 participants) indicating no evidence of a difference between the two interventions. There was a difference in the gain in CAL at three to four months (-0.25 mm, 95% CI -0.42 to -0.07, two trials, 45 participants), favouring FMD but this was not found at six to eight months. There was no evidence for a difference between FMS and FMD for BOP (-1.59, 95% CI -9.97 to 6.80, two trials, 45 participants). Analyses were conducted for different teeth types (single- or multi-rooted) and for teeth with different levels of probing depth at baseline, for PPD, CAL and BOP. There was insufficient evidence of a benefit for either FMS or FMD. Harms and adverse events were reported in eight studies. The most important harm identified was an increased body temperature after FMS or FMD treatments. We assessed the quality of the evidence for each comparison and outcome as 'low' because of design limitations leading to risk of bias and because of the small number of trials and participants, which led to imprecision in the effect estimates. The inclusion of five additional RCTs in this updated review comparing the clinical effects of conventional mechanical treatment with FMS and FMD approaches for the treatment of chronic periodontitis has not changed the conclusions of the original review. From the twelve included trials there is no clear evidence that FMS or FMD provide additional benefit compared to conventional scaling and root planing. In practice, the decision to select one approach to non-surgical periodontal therapy over another should include patient preference and the convenience of the treatment schedule.

Plain-language summary: This review, carried out within the Cochrane Oral Health Group, is an update of one we published in 2008 and the evidence is current up to March 2015. We identified another five relevant studies for inclusion in this review and therefore this review includes 12 studies, which involved 389 participants. There is one Chinese study awaiting classification. Participants in the included studies were aged between 27 and 78 years, and there were roughly the same number of men and women involved. The studies we included had to be randomised controlled trials with at least three months of follow-up that evaluated full-mouth scaling and root planing within 24 hours. Both FMS and FMD were compared to conventional quadrant scaling and root planing, which was the control group. Participants had to have a clinical diagnosis of chronic periodontitis according to the International Classification of Periodontal Diseases. We excluded studies of people with aggressive periodontitis, systemic disorders or who were taking antibiotics. Treatment effects of FMS and FMD compared to conventional scaling and root planing (SRP) are modest and there are no clear implications for periodontal care. Harms and adverse events were reported in eight studies. The most important harm identified was an increased body temperature after FMS or FMD treatments. In practice, the decision to select one approach to non-surgical periodontal therapy over another can include patient preference and the convenience of the treatment schedule. The quality of the evidence is low for all treatment comparisons and outcomes. This is due to the small number of studies and participants involved and limitations in the study designs. Future research is likely to change findings.