Limited evidence suggests that regular scale and polish treatments (at 6-month or 12-month intervals) may reduce the level of calculus on teeth compared to no treatment, and that these reductions may be more substantial with a shorter interval between treatments (6-months instead of 12-months). Participants' self-reported perception of oral cleanliness appears to be higher for regular scale and polish treatment compared to no treatment. There was little to no difference reported in gingivitis/gingival bleeding, plaque, probing depths, oral health-related quality of life or costs from an NHS perspective for regular scale and polish treatment compared to no treatment. However, these conclusions should be interpreted with some caution, as the involvement of only one reviewer in some data extractions means reviewer error and bias cannot be ruled out. Further large, high-quality studies are required to provide additional evidence to support these conclusions, particularly with respect to adverse events.
Overall summary Low risk of bias in the review
One or two review authors were involved in data extraction; this was considered inadequate to minimise error and bias. However, all other domains were considered to be at low risk.
|A. Did the interpretation of findings address all of the concerns identified in Domains 1 to 4?||Probably no|
|B. Was the relevance of identified studies to the review's research question appropriately considered?||Probably yes|
|C. Did the reviewers avoid emphasizing results on the basis of their statistical significance?||Probably yes|
|Risk of bias in the review||Low|
|Number of studies||2|
|Number of participants||1711|
|Last search date||10 January 2018|
|Objective||To determine the beneficial and harmful effects of routine scaling and polishing for periodontal health, including at different recall intervals and when provided by dentists compared with dental care professionals (dental therapists or dental hygienists).|
|Population||Dentate adults regularly attending for dental care in primary settings.
Studies in patients with severe peridontal disease (such as alveolar bone loss involving most teeth, or people requiring referral for specialist (surgical) periodontal treatment) or patients who had previously undergone specialist periodontal treatment and were in the post-treatment ’maintenance phase’ were excluded.
|Interventions||Routine scale and polish treatment with or without oral hygiene instruction that was provided by a dentist, dental hygienist or therapist at a planned, regular interval.|
|Comparator||No scheduled scale and polish treatment; a scale and polish treatment given at a different planned, regular interval; a scale and polish treatment performed by a different type of dental professional.|
|Outcome||Primary outcome: periodontal disease, assessed by gingivitis indices (both inflammatory and bleeding on probing).
Secondary outcomes: clinical status factors (calculus and plaque indices, changes in probing depths, changes in attachment level, periodontal indices, tooth loss or adverse events); participant-centred factors (Halitosis), participant satisfaction (for example, with oral comfort, oral cleanliness, appearance (including gingival recession), care received and provider of care (i.e. dentist, therapist or hygienist), oral-health related quality of life); economic cost factors (i.e. the costs of a scale and polish).
|Study design||Randomised controlled trials (RCTs) with at least six months of follow-up.
Split-mouth studies were excluded, as this does not reflect the manner in which a routine scale and polish is delivered in practice.
In the comparison between planned, regular scale and polish (S&P) at 6- or 12-month intervals compared with no S&P, pooled analysis reported little to no difference in gingivitis/gingival bleeding for the duration of the trial (at 6-month intervals: standardised mean difference (SMD) -0.01, 95% confidence interval (CI) -0.13 to 0.11, 2 trials, n=1087 participants; at 12-month intervals: SMD -0.04, 95% CI -0.16 to 0.08, 2 trials, n=1091 participants). One study reported little to no difference in plaque (at 6-month intervals: mean difference (MD) -0.04%, 95% CI -0.13 to 0.05, 1 trial, n=207 participants; at 12-month intervals: MD 0.00%, 95% CI -0.10 to 0.09, 1 trial, n=200 participants), probing depths (at 6-month intervals: MD 0.00 mm, 95% CI -0.04 to 0.04, 1 trial, n=880 participants; at 12-month intervals: MD 0.00 mm, 95% CI -0.04 to 0.04, 1 trial, n=890 participants), oral health-related quality of life (at 6-month intervals: MD -0.30, 95% CI -1.24 to 0.64, 1 trial, n=795 participants; at 12-month intervals: MD 0.10, 95% CI (0.83 to 1.03, 1 trial, n=807 participants) or costs from an NHS perspective (at 6-month intervals: MD £0.52, 95% CI £-18.10 to £19.14, 1 trial, n=554 participants; at 12-month intervals: MD £8.14, 95% CI £-13.76 to £30.04, 1 trial, n=544 participant) for the duration of the trial.
Pooled analysis reported small reductions in calculus levels for planned, regular scale and polish (S&P) at 6- or 12-month intervals compared to no S&P (at 6-month intervals: SMD -0.32, 95% CI -0.44 to -0.20, 2 trials, n=1084 participants; at 12-month intervals: SMD -0.19, 95% CI -0.31 to -0.07, 2 trials, n=1088 participants). One study reported higher patient perception of oral cleanliness for planned, regular scale and polish (S&P) at 6- or 12-month intervals compared to no S&P (at 6-month intervals: risk ratio (RR) 1.83, 95% CI 1.28 to 2.63, 1 trial, n=205 participants; at 12-month intervals: RR 1.65, 95% CI 1.13 to 2.40, 1 trial, n=200 participants).
In the comparison between planned, regular scale and polish (S&P) at 6- or 12-month intervals vs. S&P at a different planned, regular interval, pooled analysis reported little or no difference in gingivitis/gingival bleeding (SMD -0.03, 95% CI -0.09 to 0.15, 2 trials, n=1090 participants) at 6-month intervals compared to 12-month intervals at 24 to 36 months of follow-up. One study reported little to no difference in plaque (MD -0.04%, 95% CI -0.13 to 0.05, 1 trial, n=207 participants), probing depths (MD 0.00 mm, 95% CI -0.04 to 0.04, 1 trial, n=882 participants), patient perception of oral cleanliness (RR 1.11, 95% CI 0.85 to 1.47, 1 trial, n=207 participants), oral health-related quality of life (MD -0.40, 95% CI -1.34 to 0.54, 1 trial, n=786 participants) or costs from an NHS perspective (MD £-7.62, 95% CI £-28.39 to £13.15, 1 trial, n=556 participants) at 6-month intervals compared to 12-month intervals at 24 to 36 months of follow up.
Pooled analysis reported small reductions in calculus levels for 6-month interval S&P compared to 12-month interval S&P (SMD -0.13, 95% CI -0.25 to -0.01, 2 trials, n=1086 participants) at 24 to 36 months of follow up.
No studies reported a comparison between S&P treatment provided by a dentist compared with a dental care professional (dental therapist or dental hygienist).
The objectives and eligibility criteria were clearly defined and appeared appropriate for the review question. No restrictions were placed on language, publication date or publication format. Restrictions were placed on outcomes; however, these were considered appropriate.
|1.1 Did the review adhere to pre-defined objectives and eligibility criteria?||Probably yes|
|1.2 Were the eligibility criteria appropriate for the review question?||Probably yes|
|1.3 Were eligibility criteria unambiguous?||Probably yes|
|1.4 Were all restrictions in eligibility criteria based on study characteristics appropriate (e.g. date, sample size, study quality, outcomes measured)?||Probably yes|
|1.5 Were any restrictions in eligibility criteria based on sources of information appropriate (e.g. publication status or format, language, availability of data)?||Probably yes|
|Concerns regarding specification of study eligibility criteria||Low|
Cochrane Oral Health's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid and Embase Ovid databases were searched to identify relevant literature. Clinicaltrials.gov and the World Health Organisation (WHO) clinical trials registry platform were searched to identify ongoing studies. The reference lists of all related review articles and all included full text articles were checked to identify additional studies. The authors of eligible studies and researchers in the field were contacted, where possible and necessary, to obtain information on additional unpublished or published studies. The search strategy was reported in full and appeared to be appropriate. No search restrictions were placed on date, publication format or language. Two authors were independently involved in title and abstract screening, and at least two authors were independently involved in screening at the full text stage; any disagreements were resolved through mutual discussion with additional team members.
|2.1 Did the search include an appropriate range of databases/electronic sources for published and unpublished reports?||Probably yes|
|2.2 Were methods additional to database searching used to identify relevant reports?||Probably yes|
|2.3 Were the terms and structure of the search strategy likely to retrieve as many eligible studies as possible?||Probably yes|
|2.4 Were restrictions based on date, publication format, or language appropriate?||Probably yes|
|2.5 Were efforts made to minimise error in selection of studies?||Probably yes|
|Concerns regarding methods used to identify and/or select studies||Low|
One or two review authors were involved in data extraction; this was considered inadequate to minimise error and bias. Sufficient study characteristics were provided to enable interpretation of the results. All relevant study results appear to have been collected for the synthesis. Risk of bias was assessed using the Cochrane tool for assessing risk of bias in randomised trials for standard randomised controlled trials; and further risk of bias domains were assessed for trials involving cluster randomisation. Two authors were independently involved in the risk of bias assessment.
|3.1 Were efforts made to minimise error in data collection?||Probably no|
|3.2 Were sufficient study characteristics considered for both review authors and readers to be able to interpret the results?||Probably yes|
|3.3 Were all relevant study results collected for use in the synthesis?||Probably yes|
|3.4 Was risk of bias (or methodological quality) formally assessed using appropriate criteria?||Probably yes|
|3.5 Were efforts made to minimise error in risk of bias assessment?||Probably yes|
|Concerns regarding methods used to collect data and appraise studies||High|
The synthesis appeared to included all relevant studies. All pre-defined analyses appeared to be reported. The synthesis appeared to be appropriate; meta-analysis was performed to pool studies where possible and appropriate, Heterogeneity was assessed using the I2 statistic, and was found to be low for all outcomes. Sensitivity or sub-group analyses were planned, but could not be performed due to the small number of included studies (<10); this was considered to be appropriate. Publication bias was not formally assessed due to the small number of included studies (<10); this was considered to be appropriate.
|4.1 Did the synthesis include all studies that it should?||Probably yes|
|4.2 Were all pre-defined analyses reported or departures explained?||Probably yes|
|4.3 Was the synthesis appropriate given the degree of similarity in the research questions, study designs and outcomes across included studies?||Probably yes|
|4.4 Was between-study variation minimal or addressed in the synthesis?||Probably yes|
|4.5 Were the findings robust, e.g. as demonstrated through funnel plot or sensitivity analyses?||Probably yes|
|4.6 Were biases in primary studies minimal or addressed in the synthesis?||Probably yes|
|Concerns regarding synthesis and findings||Low|