Periodontal health: no additional benefit from 6 monthly Scale and Polish


Periodontal disease is one of the most common non-communicable diseases and is a major cause of poor oral health and an important cause of tooth loss in older adults.  Effective plaque control by the individual is a cornerstone of successful prevention and management of periodontal disease however there is no agreed published content of oral hygiene advice (OHA) to encourage effective self-care or evidence to inform different types of OHA that could be delivered in a dental practice setting.  Periodontal instrumentation (PI) or ‘scale and polish’ removes plaque and calculus to facilitate oral hygiene. However, the evidence to support the effectiveness and optimal frequency is limited (Worthington,2013).

The aim of this study was to compare the clinical effectiveness and cost-effectiveness of theory-based, personalised OHA or PI at different time intervals (no PI, 12-monthly PI or 6-monthly PI), or their combination, with routine care in improving periodontal health in dentate adults attending general dental practice.


This was a multicentre, cluster randomised controlled, open trial with blinded outcome evaluations and 3-year follow-ups. Dental practices were randomised to either a routine or personalised OHA group with practice patients being randomised to one of three groups: (1) no PI, (2) 6-monthly PI (current practice) or (3) 12-monthly.  NHS Dental practices in Scotland and North-East England were recruited.  Patients 18 or older with gingivitis or moderate periodontitis (BPE 0,1,2,3) were recruited.

The routine OHA was as currently provided by the practices, the Personalised OHA intervention was based on social cognitive theory and implementation intention theory. The content being personalised according to the dentist’s/hygienist’s assessment of the patients need.

The PI was as used in standard practice with no adjunctive subgingival therapy.

The primary objectives were to test the clinical effectiveness and cost-effectiveness of the following dental management strategies:personalised

  1. OHA versus routine OHA
  2. 6-monthly PI versus 12-monthly PI
  3. 6-monthly PI versus no PI.

The secondary objectives were to: test the clinical effectiveness and cost-effectiveness of a combination of personalised OHA with different time intervals for PI; measure dentist/hygienist beliefs relating to giving OHA, PI and maintenance of periodontal health.

In addition, a within-trial cost–benefit analysis assessed the costs and benefits (in monetary terms) of each policy compared with standard care and a discrete choice experiment (DCE), administered to a nationally representative online sample of the UK general population, was used to estimate willingness to pay (WTP).


  • 63 dental practices and 1877 participants were recruited.
  • The mean number of teeth and percentage of bleeding sites was 24 and 33%, respectively.
  • Two-thirds of participants had BPE scores of ≤ 2.
  • Under intention-to-treat analysis, there was no evidence of a difference in gingival inflammation/ bleeding between the 6-monthly PI group and the no-PI group [difference 0.87%, 95% confidence interval (CI) –1.6% to 3.3%; p = 0.481] or between the 6-monthly PI group and the 12-monthly PI group (difference 0.11%, 95% CI –2.3% to 2.5%; p = 0.929).
  • There was also no evidence of a difference between personalised and routine OHA (difference –2.5%, 95% CI –8.3% to 3.3%; p = 0.393).
  • There was no evidence of a difference in self-efficacy between the 6-monthly PI group and the no-PI group (difference –0.028, 95% CI –0.119 to 0.063; p = 0.543) and no evidence of a clinically important difference between the 6-monthly PI group and the 12-monthly PI group (difference –0.097, 95% CI –0.188 to –0.006; p = 0.037).
  • Compared with standard care, no PI with personalised OHA had the greatest cost savings: NHS perspective –£15 (95% CI –£34 to £4) and participant perspective –£64 (95% CI –£112 to –£16).
  • The DCE shows that the general population value these services greatly. Personalised OHA with 6-monthly PI had the greatest incremental net benefit [£48 (95% CI £22 to £74)]. Sensitivity analyses did not change conclusions.


The authors concluded: –

There was no additional benefit from scheduling 6-monthly or 12-monthly PIs over not providing this treatment unless desired or recommended, and no difference between OHA delivery for gingival inflammation/bleeding and patient-centred outcomes. However, participants valued, and were willing to pay for, both interventions, with greater financial value placed on PI than on OHA.


This large, detailed and well conducted multi-centre randomised controlled is described in an extensive open access monograph from the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme.  The full protocol have been published previously ( Clarkson et al 2013)  It found no benefit for gingival health from 6 monthly scale and polish compared with 12 monthly scale and polish in adults with early signs of gum disease. There was also no added benefit of providing personalised oral health advice.

The study clearly highlights the lack of clinical benefit from 6 monthly scale and polish which raises important policy implications as NHS contracts support the ’routine provision’ of 6 monthly scale and polish involving a not insignificant financial resource. The lack of clinical benefit for patients with a BPE scores below 3 needs to be contrasted with the high level of value which the public places on the ‘routine’ scale and polish which has broader implications for introducing changes to existing systems.


Primary Paper

Ramsay CR, Clarkson JE, Duncan A, Lamont TJ, Heasman PA, Boyers D, Goulão B,Bonetti D, Bruce R, Gouick J, Heasman L, Lovelock-Hempleman LA, Macpherson LE,McCracken GI, McDonald AM, McLaren-Neil F, Mitchell FE, Norrie JD, van der Pol M,Sim K, Steele JG, Sharp A, Watt G, Worthington HV, Young L. Improving the Quality of Dentistry (IQuaD): a cluster factorial randomised controlled trial comparing the effectiveness and cost-benefit of oral hygiene advice and/or periodontalinstrumentation with routine care for the prevention and management of periodontal disease in dentate adults attending dental primary care. Health Technol Assess. 2018 Jul;22(38):1-144. doi: 10.3310/hta22380. PubMed PMID: 29984691.

Other references

Worthington HV, Clarkson JE, Bryan G, Beirne PV. Routine scale and polish for periodontal health in adults. Cochrane Database of Systematic Reviews 2013, Issue 11. Art. No.: CD004625. DOI: 10.1002/14651858.CD004625.pub4.

Clarkson JE, Ramsay CR, Averley P, Bonetti D, Boyers D, Campbell L, Chadwick GR, Duncan A, Elders A, Gouick J, Hall AF, Heasman L, Heasman PA, Hodge PJ, Jones C, Laird M, Lamont TJ, Lovelock LA, Madden I, McCombes W, McCracken GI, McDonald AM, McPherson G, Macpherson LE, Mitchell FE, Norrie JD, Pitts NB, van der Pol M, Ricketts DNj, Ross MK, Steele JG, Swan M, Tickle M, Watt PD, Worthington HV,Young L. IQuaD dental trial; improving the quality of dentistry: a multicentre randomised controlled trial comparing oral hygiene advice and periodontal instrumentation for the prevention and management of periodontal disease in dentate adults attending dental primary care. BMC Oral Health. 2013 Oct 26;13:58.doi: 10.1186/1472-6831-13-58. PubMed PMID: 24160246; PubMed Central PMCID: PMC4015981.










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