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Ó 2009 John Wiley & Sons A/S
Community Dent Oral Epidemiol 2010; 38: 83–87
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The effects of lavender scent on
dental patient anxiety levels: a
cluster randomised-controlled
trial
Metaxia Kritsidima, Tim Newton and
Koula Asimakopoulou
King’s College London, Dental Institute,
Denmark Hill, London, UK
Kritsidima M, Newton T, Asimakopoulou K. The effects of lavender scent on
dental patient anxiety levels: a cluster randomized-controlled trial. Community
Dent Oral Epidemiol 2010; 38: 83–87. Ó 2009 John Wiley & Sons A/S
Abstract – Objectives: To review the effect of lavender scent on anticipatory
anxiety in dental participants. Methods: In a cluster randomized-controlled
trial, patients’ (N = 340) anxiety was assessed while waiting for a scheduled
dental appointment, either under the odor of lavender or with no odor.
Current anxiety, assessed by the brief State Trait Anxiety Indicator (STAI-6),
and generalized dental anxiety, assessed by the Modified Dental Anxiety
Scale (MDAS) were examined. Results: Analyses of variance (anovas)
showed that although both groups showed similar, moderate levels of
generalized dental anxiety (MDAS F (1,338) = 2.17, P > 0.05) the lavender
group reported significantly lower current anxiety (STAI: F(1,338) = 74.69,
P < 0.001) than the control group. Conclusions: Although anxiety about
future dental visits seems to be unaffected, lavender scent reduces state
anxiety in dental patients.
Dental anxiety has been defined as an ‘Abnormal
fear or dread of visiting the dentist for preventive care or
therapy and unwarranted anxiety over dental procedures’ (1) and can have physiological, cognitive and
behavioral consequences (2). Humphris refers to
anxiety as an aversive psychological construct,
unpleasant to experience and almost always associated with a specific event, which takes time to
dissipate (3). Anxiety toward the dental profession
is very common. A third of the UK adult population describe themselves as dentally anxious (4).
Furthermore, 43% report avoid going to the dentist
(5) and 58% of UK adults state that this is partly
attributed to their being ‘scared of the dentist’ (6).
Dental anxiety also affects the working lives of
dental professionals. Dealing with anxious patients
leads to increased tension that may potentially
compromise performa,nce. Increased time per visit
may be required. Managing dental anxiety has
doi: 10.1111/j.1600-0528.2009.00511.x
Key words: complementary therapy; dental
anxiety; dental phobia
Koula Asimakopoulou, King’s College
London, Dental Institute, Denmark Hill, SE5
9RW, London, UK
Tel.: +44 (0)203 2993272
Fax: +44 (0)203 2993409
e-mail: [email protected]
Submitted 24 November 2008;
accepted 19 September 2009
been suggested as one of the most difficult tasks for
dental practitioners (3, 7, 8).
One common way of managing anxiety in the
dental surgery is through conscious sedation or
general anesthesia. Patients who are not too anxious to visit the dental surgery in the first place, can
be offered sedative drugs or general anesthesia to
suppress their fear of the dentist and undergo
clinical examination and routine dental procedures. The problems with these procedures however are that, in addition to carrying some risk,
they require special knowledge and equipment (9)
hence they cannot be routinely performed in any
dental clinic. Additional drawbacks are factors
such as patient allergies, the existence of other
medical conditions or use of other medications that
may interfere with sedative medication. Behavioral
management methods of dental anxiety on the
other hand, require additional time per visit and
83
Kritsidima et al.
professional expertise; as very few dentists are in
partnership with psychologists and even fewer can
find the time to provide this treatment themselves,
behavioral methods remain an effective yet not
always practical alternative to medication.
Recently, alternative treatment approaches such
as aromatherapy [that is the application of essential
oils of aromatic plants (10)] have received attention
in medical (11–15) and dental (16–18) settings. The
idea behind this method is that common oils can be
used to produce a positive physiological or pharmacological effect through the sense of smell (19).
For example, although lavender oil has traditionally been used as an antiseptic agent, it has also
been recommended as a relaxant, carminative, and
sedative (11, 15). Such an approach offers a potentially valuable technique for dealing with mild to
moderate anticipatory dental anxiety.
There have been only very few studies evaluating the effects of aromatherapy on dental anxiety (16–18). Generally, findings have suggested
that aromatherapy may be a useful means of
alleviating dental anxiety (16, 17). These findings
however, have been arrived at through studies
that have used fairly small samples (16, 17) or
extensive patient questioning (16, 17) which could
in itself have added to patient anxiety. What is
more, none of these studies have evaluated anxiety systematically; for example, the majority have
failed to differentiate between state anxiety, that
is, how the patient is feeling at the time of
measurement and general dental anxiety, that is,
how the person generally feels about visiting the
dentist.
To address previous research limitations, we
designed an appropriately powered randomizedcluster controlled trial to assess the effects of
lavender oil on anxiety in dental patients. In
addition to the Modified Dental Anxiety Scale
(MDAS) (20, 21) as a measure of dental anxiety, we
used a brief measure of state anxiety [STAI-6 (22)].
In line with previous work we predicted that
lavender would reduce anxiety in dental patients.
reduce state and dental anxiety in patients waiting
to see their dentist.
The study was conducted in accordance with the
principles of research ethics outlined in the Helsinki Declaration. Currently, there is no established
ethics committee in Greece (23).
Participants
Sample size calculation. Using a confidence level of
95% and a 90% power to detect a medium effect
(f = 0.25) across two groups we calculated (24) that
338 participants needed to be recruited into the
study.
Sample eligibility, selection and randomization. All
adults over 18 years who arrived at the dental
practice for dental treatment during the study
period and who could read and write Greek were
eligible to participate. Patients with allergies and
common cold conditions were excluded. The
demographic characteristics of the sample as well
as the reason for their dental visit are shown in
Table 1.
Of the N = 343 patients who were eligible to
participate, N = 340 agreed to take part. A flow
chart describing the recruitment procedure appears
in Fig. 1.
Materials
A candle warmer, candle, plain water and lavender
oil were used. The candle warmer comprised a
lower compartment with an aroma-free candle and
an upper compartment containing water, either
with (Lavender condition) or without lavender oil
(Control condition).
An information sheet was used, inviting participants to take part in a study investigating
‘people’s mood’. Participants were told that they
Table 1. Demographic and anticipated treatment profile
of study participants
Condition
Methods
Design and ethics
In a single (patient)-masked randomized-controlled trial we investigated the effect of lavender
scent on dental anxiety in a private dental practice
in Athens, Greece. Using a between participants
design we hypothesized that lavender scent will
84
Lavender
(N = 170)
Male (N)
85
Mean (SD) age
40.02 (13.35)
Smokers (N)
75
Anticipated dental treatment
Check-up
23
Dental hygiene
55
Drilling
72
Extraction
8
Pain control
12
Control
(N = 170)
85
38.56 (12.19)
76
24
52
74
7
13
Lavender and dental anxiety
Screened / eligible
to participate
n = 343
Agreed
to participate
n = 340
Week 1
Control
n = 103
Week 2
Lavender
n = 101
Procedure
n = 2 not eligible
Allergies n = 2
Cold n = 0
n = 3 refused to
participate due to
illiteracy
Week 3
Lavender
n = 69
Week 4
Control
n = 67
Control
n = 170
Lavender
n = 170
Completed
n = 170
Completed
n = 170
Analysis
n = 170
Analysis
n = 170
Fig. 1. Recruitment flow chart.
would complete two brief questionnaires and a
demographic information sheet and that questionnaires had no right or wrong answers. A demographic information sheet, gathering information
regarding participants’ age, gender, smoking status, allergies, common cold condition and finally
the dental procedure they anticipated having (regular check up, dental hygiene, dental drilling, tooth
pulling or pain control) was used.
Dental anxiety was measured by the Modified
Dental Anxiety Scale. This five-item questionnaire
is measured on a Likert scale from 1 to 5 with
higher scores indicating higher anxiety. Likewise,
the six-item State Trait Anxiety Inventory (STAI-6)
was used to assess state anxiety rated on a fourpoint Likert scale. Both of these reliable and valid
measures (21, 25, 26) were translated to Greek and
back translated by experts in these two languages
in order to ensure reliability. The psychometric
properties of the Greek versions of the MDAS
and STAI have been established in previous work
(27, 28).
The experiment took place between 4th and 30th
June 2007. Participants attending over the 4 weeks
(N = 340), were allocated to the control and lavender groups as a block by week, by a dental practice
secretary who was blind to the study purpose and
design. The treating dentist took no part in the
randomization procedure.
Control data were collected during weeks 1 and
4 and lavender condition data were obtained
during weeks 2 and 3. For the latter, five drops of
lavender oil was dropped by the researcher in 10 cc
water twice a day just before the start of the
morning and afternoon clinics. The oil was diffused
via a ceramic candle warmer which kept the
ceramic warm for a period of four hours. The same
ceramic candle warmer was used in the control
condition (weeks 1 and 4). However, lavender oil
was replaced by plain water, applied in a similar
manner. In both cases, the candles used were
aroma free. Good ventilation of the waiting room at
the transition from the treatment condition to the
control condition (during the weekend between
weeks 3 and 4) allowed lavender scent to be
completely removed from furniture and premises.
Patients completed all measures while waiting
for treatment in the waiting room. Answering the
questions was entirely self-paced. Following dental
treatment, participants were thanked and fully
debriefed.
Results
Data were collated and entered into spss v.15 for
analysis. As can be seen in Table 1, there were no
differences between conditions in gender, smoking
status, or type of procedure (F (1,338) = 0.11,
P > 0.05). Mean, range, and SD dental (MDAS) and
state (STAI-6) anxiety were calculated. The data
appear in Table 2.
A simple one-way anova was performed on
MDAS scores, which suggested no differences in
dental anxiety between the lavender and control
groups (F (1, 338) = 2.17, P > 0.05). STAI-6 scores,
Table 2. Mean, range and SD of dental and state anxiety scores, per condition
Lavender (N = 170)
Control (N = 170)
Condition
MDAS
STAI-6
MDAS
STAI-6
Mean (SD)
Range (min-max)
9.84 (4.74)
19 (5–24)
7.41 (2.43)
12 (6–18)
10.65 (5.40)
20 (5–25)
10.71 (4.35)
16 (6–22)
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Kritsidima et al.
however, reflecting participants’ self-reported state
anxiety did appear to be somewhat different
between the control and lavender conditions
(Table 2). This difference was confirmed through
an one-way anova where the lavender group
reported significantly lower levels of anxiety than
the control group (F(1,338) = 74.69, P < 0.001).
No other statistical analyses were performed. No
adverse events were recorded in either the intervention or control group.
Discussion
The results in this study indicate that lavender
scent reduces states anxiety as measured by STAI6, however, it has no effect on dental anxiety
surrounding thoughts of future dental visits, as
measured by the MDAS. The data showing a
reduction in state anxiety are in agreement with
previous studies conducted in a dental setting (17).
In an extension of previous work, however, the
current intervention failed to reduce dental anxiety
as measured by the MDAS.
We argue that our findings are attributable to the
difference in the nature of anxiety measured by the
STAI-6 and MDAS. The STAI-6 assesses state
anxiety, which occurs as an immediate response
to a threatening situation; it measures how the
individual feels at the moment of the question, that
is, ‘how they feel right now’. On the other hand, the
MDAS assesses levels of anxiety in specific, yet
hypothetical, future dental situations; as such it
measures patients’ thoughts about future anxiety.
Dental anxiety has both an affective and a cognitive
component. It would appear that while lavender
reduces affective aspects of anxiety, it has no effect
on cognitive components. This is an interesting
finding which needs further research.
Although it was beyond the purpose of the
present work to investigate the physiological
mechanisms that may be responsible for the effects
of lavender scent on anxiety, the mechanism by
which lavender might reduce state anxiety has
been studied by others. The finding that odors can
influence the emotional state of human beings is
not new (29); this finding has been supported by
neuroimaging work showing emotional changes as
a direct result of olfactory stimulation. As olfactory
processing is directly linked to the limbic system
including the amygdala, such a process can produce emotional changes (30). The same study
argued that lavender probably acts post-synaptic-
86
ally, and suggested that it may modulate the
activity of cyclic adenosine monophosphate
(cAMP). A reduction in cAMP activity is associated
with sedation and a causal relationship between
cAMP reduction and relaxation has been shown in
work looking at the effects of cannabis on behavior
(30). It would thus appear that the effectiveness of
lavender as an anxiety reduction method seems to
lie in its ability to promote relaxation through the
autonomic nervous system (30).
We conclude that lavender is an effective means
of reducing current state anxiety, but has no effect
on future anxiety-provoking thoughts. In this
sense, lavender should be perceived as a means
of ‘on-the-spot’ reduction of anxiety and not as an
anxiety treatment. Given these findings and in line
with previous work which has clearly argued the
importance of using multiple measures of dental
anxiety in research settings (31) we propose that
interventions aiming to reduce anxiety in dental
settings should consider measuring anxiety several
ways.
There are some limitations to the study. As we
did not include a control odor, the lavender scent
might have simply masked odors in the dental
surgery that patients associate with dentistry (such
as menthol). As such, it could be that it was a
masking of dentistry-related odors that was
responsible for the effect we saw, rather than
lavender per se. Future work should consider
including a control odor condition in replicating
this study. It could also be that, although reliable
(26) the MDAS is less sensitive than the STAI-6 in
detecting anxiety manipulations. Currently, there
are no formal sensitivity to change data for the
MDAS. However, work by Newton and Edwards
(26) found the MDAS to be sensitive to anxiety
manipulations in a behavioral intervention with
dentally anxious patients, suggesting that the
instrument may be robust enough. Nevertheless,
given the limitations identified here, our hypotheses need further confirmation in future work.
This randomized control clinical trial provides
evidence in favor of the use of lavender scent in
dental settings as a low cost, simple intervention
for alleviating affective components of dental
patient anxiety. The results are likely to be generalizable to patients with levels of dental anxiety
below the level of phobia who are attending
general dental practice. As lavender has no effect
on the cognitive aspects of anxiety and hence at the
processes which are likely to maintain anxietyprovoking thoughts and behaviors, we argue that
Lavender and dental anxiety
such aspects of dental anxiety are targeted via
appropriate behavioral interventions (32).
References
1. Online Medical Dictionary 1998 [cited 2008]; Available from: http://cancerweb.ncl.ac.uk/cgi-bin/
omd?dental+anxiety.
2. Locker D. An introduction to behavioural science
and dentistry. London: Tavistock Routledge, 1989;
145–60.
3. Humphris G, Ling MS. Behavioural Sciences for
Dentistry. Edinburgh: Churchill Livingstone, 2000;
71–85.
4. Todd JE, Lader D. Adult dental health 1988 United
Kingdom. London: Her Majesty’s Stationery Office;
1991.
5. Todd JE, Walker A. Adult dental health in England
and Wales. London: HMSO; 1980 189(11).
6. Todd JE, Walker A, Dodd P. Adult dental health.
London: HMSO; 1982.
7. Kleinknecht RA, Klepac RK, Alexander LD. Origins
and characteristics of fear of dentistry. J Am Dent
Assoc 1973;86:842–8.
8. Kent GG, Blinkhorn AS. The psychology of dental
care. 2nd edn. Oxford: Wright, 1991; 55–98.
9. Coulthard P. Conscious sedation guidance. Evid
Based Dent 2006;7:90–1.
10. Charman RA. Complementary therapies for physical
therapists: a theoretical and clinical exploration.
Professional Complementary Medicine. Wolburn,
MA: Butterworth-Heinemann, Reed Educational &
Professional Publishing Ltd., 2000; 231–3.
11. Long L, Huntley A, Ernst E. Which complementary
and alternative therapies benefit which conditions? A
survey of the opinions of 223 professional organizations. Complement Ther Med 2001;9:178–85.
12. Buckle J. The role of aromatherapy in nursing care.
Nurs Clin North Am 2001;36:57–72.
13. Thompson C. Oil on troubled waters? Nurs Times
2001;97:24–5.
14. Lee SY. The effect of lavender aromatherapy on
cognitive function, emotion, and aggressive behavior
of elderly with dementia. Taehan Kanho Hakhoe Chi
2005;35:303–12.
15. Evandri MG, Battinelli L, Daniele C, Mastrangelo S,
Bolle P, Mazzanti G. The antimutagenic activity of
Lavandula angustifolia (lavender) essential oil in the
bacterial reverse mutation assay. Food Chem Toxicol
2005;43:1381–7.
16. Lehrner J, Eckersberger C, Walla P, Potsch G, Deecke
L. Ambient odor of orange in a dental office reduces
anxiety and improves mood in female patients.
Physiol Behav 2000;71:83–6.
17. Lehrner J, Marwinski G, Lehr S, Johren P, Deecke L.
Ambient odors of orange and lavender reduce
anxiety and improve mood in a dental office. Physiol
Behav 2005;86:92–5.
18. Hainsworth JM, Moss H, Fairbrother KJ. Relaxation
and complementary therapies: an alternative
approach to managing dental anxiety in clinical
practice. Dent Update 2005;32:90–2.
19. Schnaubelt K. Advanced aromatherapy, the science
of essential oil therapy. Rochester: Healing Arts
Press; 1998.
20. Corah NL. Development of a dental anxiety scale.
J Dent Res 1969;48:596.
21. Humphris GM, Morrison T, Lindsay SJ. The Modified Dental Anxiety Scale: validation and United
Kingdom norms. Community Dent Health
1995;12:143–50.
22. Marteau TM, Bekker H. The development of a sixitem short-form of the state scale of the Spielberger
State-Trait Anxiety Inventory (STAI). Br J Clin
Psychol 1992; 31(Pt3):301–6.
23. Marketos SM, Garanis TN. Ethics committees in
Greece. HEC Forum 1994;6:121–4.
24. Cunningham JB, McCrum-Gardner E. Power, effect
and sample size using GPower: practical issues for
researchers and members of research ethics committees. Evidence Based Midwifery 2007;5:132–6.
25. Tunc EP, Firat D, Onur OD, Sar V. Reliability and
validity of the Modified Dental Anxiety Scale
(MDAS) in a Turkish population. Community Dent
Oral Epidemiol 2005;33:357–62.
26. Newton JT, Edwards JC. Psychometric properties
of the modified dental anxiety scale: an independent
replication.
Community
Dent
Health
2005;22:40–2.
27. Coolidge T, Arapostathis KN, Emmanouil D, Dabarakis N, Patrikiou A. Economides N. Kotsanos N.
Psychometric properties of Greek versions of the
Modified Corah Dental Anxiety Scale (MDAS) and
the Dental Fear Survey (DFS). BMC Oral Health
2008;8:29.
28. Liakos A, Giannitsi S. Reliability and validity of the
Greek translation of the Spielberger’s Anxiety Inventory. Engefalos 1984;21:71–6.
29. Burnett KM, Solterbeck LA, Strapp CM. Scent and
mood state following an anxiety-provoking task.
Psychol Rep 2004;95:707–22.
30. Balchin M, Land HartS. Studies on the mode of
action of the essential oil of lavender (Lavandula
angustifolia P. Miller). Phytother Res 1999;13:540–2.
31. Schuurs A, Hoogstraten J. Appraisal of dental anxiety and fear questionnaires: a review. Community
Dent Oral Epidemiol 1993;21:329–39.
32. Kvale G, Berggren U, Milgrom P. Dental fear in
adults: a meta-analysis of behavioural interventions.
Community Dent Oral Epidemiol 2004;32: 250–64.
87