Commentary

For more than 50 years the oral health anthem, sung by dentists to patients, was “brush and floss twice per day, and see your dentist twice a year”. Now, this review on professional mechanical plaque removal (along with another review on flossing by Hujoel et al 1), questions whether these interventions provide patients with an oral health benefit. Or more accurately, this review questions the data upon which this anthem is based.

The implications are profound. In the USA expenditures for preventive periodontal care are more than $14 billion per year2. In an era when U.S. health care costs are expected to double over the next 7 years, curtailing this benefit would significantly impinge on a patient's expectations of care and a dentist's income. At the same time, with limited resources, from a governmental or insurers perspective, providing value for money is a paramount concern.

The study is based on review of more than 2000 randomized controlled trials, controlled trials, and cohort trials, reported between 1950 and 2004. The results indicate for plaque and gingivitis, but not pocket depth or attachment level, professional mechanical plaque removal + oral hygiene instruction is as effective as oral hygiene instruction alone, and both are better than no treatment. There is little evidence on the optimum frequency and little or conflicting evidence on the effects on pocket depth or attachment level. Table 1 summarizes the findings.

Table 1 Summary of the effects of the various interventions
Full size table

There are also some interesting and noteworthy contradictions, extrapolations, and limitations that this review raises. For example:

  • Increased frequency of PMPR was not associated with increased health. In fact, the contrary was found. Increased frequency of PMPR could lead to increased attachment loss.

  • The common practice in U.S. dental hygiene programs is to teach rubber cup prophylaxis. The data suggests that rubber cup and air polishing have equivalent efficacies.

  • While PMPR + OHI appeared to be more effective than PMPR alone, recent reviews suggest that the efficacy of self performed plaque control is not optimal. 1, 3

  • The recent reviews4, 5 comparing scaling and root planing + systemic antibiotics indicate that the combination is more effective than scaling and root planing alone. Given the current results, one wonders whether OHI + systemic antibiotics would be as effective as SRP + antibiotics.

  • Other data associates periodontal disease with increased risk of systemic medical conditions6 (eg: pre-term low birth, cardiac disease, diabetic control, or stroke). One might have previously suspected that the periodontal intervention of choice would be scaling and root planing ± surgery. The results of the current review, however, suggest that PMPR + OHI may be an effective preventive intervention. Preliminary data supporting this hypothesis was identified by Adachi7.

Finally, the identified studies were largely carried out in academic settings, were often underpowered, did not analyze smoking as a covariate, and did not include children. Thus, while the review presents the best available evidence, it also highlights the need for appropriately sized trials, carried out in clinical practice settings, of a duration long enough to demonstrate or refute effectiveness. From a patient's or clinician's perspective, this may be a mute point, the default perspective being, more prevention can't hurt. From a public health perspective, however, at an estimated U.S. cost for PMPR of >$28 billion by 2014, there will be significant pressure to demonstrate clinical effectiveness and significance.