Do anti-oxidant essential oils reduce gingival inflammation for orthodontic patients?
Every now and then a paper is published that stands out because it reports on a study that is rather unusual for orthodontic research. This paper is clearly different as the authors report on new research using an anti oxidant and essential oil mixture for improving the gingival health of orthodontic patients. I think that it is great to see this type of research that may lead to changes in the advice that we may give to our patients.
Benjamin J. Martin, Phillip M. Campbell, Terry D. Rees, and Peter H. Buschang
Angle Orthodontist advanced publication
In the introduction they explained that there is increasing evidence from periodontal research that antioxidants may be useful in treating gingivitis.
As a result the aim of this study was to;
“Evaluate the efficacy of the topical gel containing phloretin and ferulic and essential oils in the treatment of gingivitis in orthodontic patients”.
I was a little unclear as to what essential oils were; so I looked it up in Wikipedia. This is their definition:
“An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils have been used medicinally in history. Medical applications proposed by those who sell medicinal oils range from skin treatments to remedies for cancer and often are based solely on historical accounts of use of essential oils for these purposes. Claims for the efficacy of medical treatments, and treatment of cancers in particular, are now subject to regulation in most countries”.
What did they do?
They randomly allocated 32 young adults who were having treatment with fixed appliances to receive a placebo gel or an active treatment which consisted of the same jail containing the antioxidants phloretin and ferulic acid in addition to essential oils.
They carried out a sample size calculation, they gave no details of randomisation method or concealment. This increases the possibility of bias.
The patients received oral hygiene instruction and they were asked to apply a pea sized amount of the gel to their gingivae twice a day immediately after brushing.
An examiner, who was blinded to the allocation, recorded Probing Depth, Bleeding on Probing, Plaque Index and Gingival Index.
They collected this information at the start (T1) their next visit (T2) and a month later (T3). They asked the patients to stop using the gel between (T2) and (T3). I was not sure why they did this and so I shall not expand on this data.
They carried out simple univariate tests with the man Whitney U test because of the small sample size.
What did they find?
I have extracted the data from T1 T2 to this table.
|Bleeding on probing||Probing Depth||Gingival Index||Plaque Index|
|Treatment||49.2 (40.5-57.8)||2.53 (2.4 – 2.59)||1.42 (1.3 – 1.5)||0.87 (0.73 – 1.0)|
|Control||69.1 (59.8 – 78.3)||2.64 (2.57 – 2.7)||1.61 (1.49 – 1.72)||1.17 (0.96 – 1.31)|
If we now look at these differences and their confidence intervals (which I calculated) you can see that the confidence intervals are rather wide this indicates a degree of uncertainty. It is also important to note that for the Plaque Index, Gingival Index and Probing Depth data, the confidence intervals overlap, indicating that it is likely that these differences are not statistically significant. Furthermore, you can see that these differences are rather small and may not be clinically significant. However, there does appear to be a clinical and statistically significant difference for bleeding on probing. But it is worth pointing out that at the start of treatment bleeding on probing occurred at fewer sites for the treatment group (62.9%) than the control group (72.1%).
The investigators have also calculated the percentage change within the groups and this suggests that the intervention does have an effect.
What did I think?
Firstly I’m honestly not sure about their conclusions and while I accept that my analysis may be very critical, I wonder if the findings are robust? Unfortunately, they report some of their data as percentage change, which tends to mask differences that may be small. See my post on AcceleDent.
I have other concerns that the sample size is rather small and this leads to wide confidence intervals and uncertainty. Nevertheless, there may be something to this and I feel that this study is a really good pilot and a larger more precise investigation should be carried out before we all go out buying essential oils!
Martin, B., Campbell, P., Rees, T., & Buschang, P. (2015). A randomized controlled trial evaluating antioxidant–essential oil gel as a treatment for gingivitis in orthodontic patients The Angle Orthodontist DOI: 10.2319/041515-251.1