Trisha E. O`Hehir, RDH
A column titled, "Burst your patients` bubbles by recommending dry brushing first," was published in December 1993, and this was followed up in May1996 with, "`Brush inside first` ought to be the message." The two headlines convey the foundation of any toothbrushing instruction I give, as readers and those of you who have attended my courses know.
Conversations with readers confirm that many of you are of the same thinking. Despite being a successful approach in practice, it was not supported by scientific research. So we took on that challenge. A pilot study was set up, and readers of the December 1993 column, as well as Perio Reports readers, were invited to become researchers. Our goal was to determine the effectiveness of dry brushing mandibular surfaces first.
Research on their own
Many hygienists expressed interest in the project and actually tested the idea in practice on their own. Of the many readers who tested this approach, 29 hygienists collected before and after data on a total of 126 patients. Some tested the method on just one patient, and several sent data on up to 10 patients. But the average was five patients each.
Bleeding and calculus were measured on the lingual surfaces of the mandibular teeth before instructing patients to dry brush the inside of the bottom teeth first. At their next dental hygiene visit, an average of six months later, the measurements were repeated. By the end of 1994, all the data had been collected.
As with most of my projects, it took a lot more time than I anticipated. But the numbers have finally been crunched, as they say, and an abstract of the results was presented in a poster session at the International Association of Dental Research meeting in Orlando, Fla., last month. The entire report has also been written and submitted for publication in a research journal.
We now have scientific research to support what you and I have tested in practice and found to be effective. The order of things may seem backward, since we look to science for direction in our clinical practice. To the contrary, many ideas begin in practice and are later supported by scientific research. It truly is a two-way street.
Reductions in calculus reported
Without going into statistical details, here are some of the results. Most patients followed the instructions and saw reductions in calculus and bleeding. But, as you might expect, some people forgot the instructions and no differences were seen for them. A few of the patients who did see results were so excited about the changes that they stopped by the office to show the hygienist before their next dental hygiene visit! One hygienist also used the intraoral camera to visually record calculus levels before and after. This proved to be a dramatic comparison for the patient.
We used a zero to four grading system to measure calculus and bleeding. Averaging all the baseline calculus scores together for the mandibular lingual surfaces gave us a score of 1.70. Calculus was much heavier on the mandibular six anterior teeth which started with an average calculus score of 2.40. Average calculus scores were reduced by 58 percent, and the reductions in the anterior section were 63 percent. Comparing the numbers before and after, average bleeding scores were reduced 54 percent.
But a word of caution about these scores. Unlike probing scores where 4 mm is twice as deep as 2 mm, a score of four on our scale does not necessarily mean it is twice that of a score of two. Therefore, the reductions we saw were in the scoring numbers and we can`t actually say the calculus was reduced 63 percent. The numbers are arbitrary, but they give us at least some idea of the level of bleeding and the amount of calculus before and after.
We anticipated a reduction in calculus and bleeding in the mandibular anterior region, but we were surprised to see the results of the statistical analysis. The analysis, completed by Jean Suvan, RDH, my co-author on the project, revealed that the magnitude of improvement was actually greater in the posterior.
If we plot the before and after scores in vertical lines next to each other, we will see a broad range in each group. There will be a few high scores and a few low scores in each group, but the majority of scores will cluster as a group in the middle. The cluster of baseline scores is located higher on the vertical line than the cluster of follow-up scores. This type of graph shows us the movement of scores as a whole from baseline to the follow-up appointment.
To compare anterior and posterior teeth we establish two vertical lines for each section representing bleeding and calculus. If we look at the score right in the middle of each group, we see that the anterior bleeding score was reduced by 40 percent. The middle or median bleeding score for the posterior teeth was reduced by 50 percent.
An even greater reduction was observed for calculus scores. The median calculus score for anterior teeth was reduced by 47 percent. In the posterior section, the score was reduced by 67 percent. Looking at the scores in groups, the shift toward less bleeding and less calculus was actually greater in the posterior region than the anterior.
Besides confirming effectiveness, this pilot study quantified the results, letting us know what kind of changes can be expected. The next step will be to have university researchers conduct a controlled, double-blind study.
When the hygienist giving the instructions is the same one measuring bleeding and calculus, there is bound to be some bias. A controlled study would have one person provide patient instructions and another record baseline and follow-up data. The study would also include a control group that would be monitored during the same time, but not be told to dry brush the inside surfaces first. Just being part of a study inspires people to do better, so the control group would provide that measure, the Hawthorne Effect.
The pilot study has demonstrated that dry brushing lingual surfaces first does reduce bleeding and calculus. A controlled study would provide precise measurable benefits.
My thanks go out to all the RDH readers who participated: M. Bell, M. Black, K. Brighindi-Webb, C. Callahan, W. Cloet, S. Conway, V. Edwards, D. Fahrenbach, R. Filingo, L. Fox, B. Gillogly, L. Glenn, E. Harris, S. Hatch, L. Haynes, S. Holley, J. Kahn, D. Kaminski, E. Kissner, K. Ledford, M. McKinley, J. Miller, A. Mucci, A. Neihaus, B. Ostaszewski, K. Pluger, M. Sullivan, M. Smith, C. Tutton.
You can be on my research team anytime!
Trisha E. O`Hehir, RDH, is a senior consulting editor of RDH. She also is editor of Perio Reports, a newsletter for dental professionals that addresses periodontics.