Insufficient evidence to understand effect of routine scaling and polishing:What are the benefits and harms of routine scaling and polishing for periodontal health and do these change with different time intervals?

Data sources: Relevant studies were sourced using the Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials, Medline and Embase. Reference lists from relevant articles were scanned and the authors of eligible studies were contacted where possible to identify trials and obtain additional information.Study selection: Trials were selected if they were randomised, included anyone with an erupted permanent dentition, and where subjects were judged to have received a routine scale and polish as defined in this review.a Outcomes assessed included tooth loss, plaque, calculus, gingivitis, bleeding and periodontal indices, changes in probing depth, attachment change, patient-centred outcomes and economic outcomes.Data extraction and synthesis: Trial details were independently extracted, in duplicate, by two reviewers. Authors were contacted where possible and where deemed necessary for further details regarding study design and for data clarification. A quality assessment of all included trials was carried out. The Cochrane Collaboration’s statistical guidelines were followed and both the standardised mean differences and weighted mean differences were calculated, as appropriate, using random-effects models.Results: Eight studies were included in this review and all studies were assessed as having a high risk of bias. Two split-mouth studies provided data for the comparison between scale and polish versus no scale and polish. One study, which involved people attending a recall programme following periodontal treatment, found no statistically significant differences for plaque, gingivitis and attachment loss between experimental and control units at each timepoint during the 1-year trial. The other study, of adolescents in a developing country who had high existing levels of and calculus who had not received any dental treatment for at least 5 years, reported statistically significant improvements in calculus and gingivitis (bleeding) scores between treatment and control units at 6, 12 and 22 months following a single scale and polish provided at baseline to treatment units. For comparisons between routine scale and polish procedures provided at different time intervals, there were some statistically significant differences in favour of scaling and polishing carried out at more frequent intervals, that is, at 2 weeks versus 6 months; 2 weeks versus 12 months (for the outcomes plaque, gingivitis, pocket depth and attachment change); and at 3 months versus 12 months (for the outcomes plaque, calculus and gingivitis). There were no studies comparing the effects of scaling and polishing provided by dentists or professionals complementary to dentistry. Conclusions: The research evidence is not of sufficient quality to reach any conclusions regarding the beneficial and adverse effects of routine scaling and polishing for periodontal health and regarding the effects of providing this intervention at different time intervals. High-quality clinical trials are required to address the basic questions posed in this review.a Scaling and/or polishing of the crown and root surfaces of the teeth to remove local irritational factors (plaque, calculus, debris and staining), that does not involve periodontal surgery or any form of adjunctive periodontal therapy such as the use of chemotherapeutic agents or root planing.