Many dentists or hygienists provide scaling and polishing for patients at regular intervals, even if those patients are considered to be at low risk of developing periodontal disease. There is debate over the clinical effectiveness and cost effectiveness of 'routine scaling and polishing' and the 'optimal' frequency at which it should be provided.
The main objectives were: to determine the beneficial and harmful effects of routine scaling and polishing for periodontal health; to determine the beneficial and harmful effects of providing routine scaling and polishing at different time intervals on periodontal health; to compare the effects of routine scaling and polishing provided by a dentist or professionals complementary to dentistry (PCD) (dental therapist or dental hygienist) on periodontal health.
We searched the Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), 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.
Date of most recent searches: 9th April 2003.
Trials were selected if they met the following criteria: design - random allocation of participants; participants - anyone with an erupted permanent dentition who were judged to have received a 'routine scale and polish' (as defined in this review); interventions - 'routine scale and polish' (as defined in this review) and routine scale and polish provided at different time intervals ; outcomes - tooth loss, plaque, calculus, gingivitis, bleeding and periodontal indices, changes in probing depth, attachment change, patient-centred outcomes and economic outcomes.
Data collection and analysis
Information regarding methods, participants, interventions, outcome measures and results 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 standardised mean differences and weighted mean differences were calculated as appropriate using random-effects models.
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, involving patients 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 time point during the 1 year trial. The other study, involving adolescents in a developing country with high existing levels of calculus who had not received any dental treatment for at least 5 years, reported statistically significant differences in calculus and gingivitis (bleeding) scores between treatment and control units at 6, 12 and 22 months (in favour of 'scale and polish units') following a single scale and polish provided at baseline to treatment units.
For comparisons between routine scale and polish provided at different time intervals, there were some statistically significant differences in favour of scaling and polishing provided at more frequent intervals: 2 weeks versus 6 months, 2 weeks versus 12 months (for the outcomes plaque, gingivitis, pocket depth and attachment change); 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.
The research evidence is of insufficient 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.