Animal Assisted Therapy's Effects on Dental Patients
Phase: NA
Conditions: Anxiety
Sponsor: University of North Carolina, Chapel Hill

TITLE: Evaluating effects of animal assisted therapy on anxious pediatric dental patients using
objective physiologic measures and self-reports of stress
NCT NUMBER: NCT04708028
DOCUMENT DATE: March 20, 2024

TITLE: Evaluating effects of animal assisted therapy on anxious pediatric dental patients using
objective physiologic measures and self-reports of stress
ABSTRACT:
A striking 50-80% of adults and 6-22% of children suffer from dental anxiety which leads to
disruptive behavior during appointments and avoidance of regular dental care. Though routinely used,
common pharmacological interventions (i.e. oral sedation, general anesthesia) for anxiety
management carry risks of adverse effects including stress on the respiratory and cardiovascular
systems, neurologic injury, and even death. Data from various healthcare settings show reductions in
pain and stress indicators in patients after implementation of a therapy dog for appointments.
However, few studies have explored the physiologic and subjective effects of AAT on pediatric dental
patients undergoing invasive procedures. To address this gap in knowledge and explore the
effectiveness of animal-assisted therapy (AAT) in pediatric dentistry, we will study the subjective and
objective responses of patients undergoing operative dental procedures that include an injection.
Our central hypothesis is that children who interact with a therapy dog before their dental
procedure will have significantly lower physiologic and subjective, self-reported responses to anxiety.
We will test this hypothesis with the following aims: We will measure the physiologic effects of
animal assisted therapy on pediatric patients’ stress levels by analyzing salivary stress
hormones (i.e. alpha-amylase and cortisol) during invasive dental procedures (primary aim). For
supplemental aims, we will measure participants’ heart rate throughout the dental visit, will
evaluate the patients’ self-perceptions of pain and anxiety using pre-, intra- and post-procedural
validated scales to assess responses to AAT and will analyze participants’ behaviors using
observational coding. Data will guide the implementation of AAT as a non-pharmacological
anxiety management tool in dentistry, with the goal of improving access to care and patient
safety among anxious pediatric patients.
SPECIFIC AIMS:
Dental anxiety is linked to avoidance behavior and an increased pain response during dental
procedures.1,2 At this time, limited methods for non-pharmacological anxiety control exist. The burden
of sedation dentistry comes with many risks and financial costs. Some serious unwanted side effects
include compromise to the patient’s respiratory drive, airway reflexes and airway patency, as well as
the cardiovascular system.3 Sedation for anxiety control is also costly for the patient and healthcare
system, with deleterious effects on access to care. Dentistry is in need of anxiety control
measures other than pharmacological sedation to reduce the risk to patients, lower the cost of
treatment and thus increase access to dental care. One promising approach is animal-assisted
therapy (AAT) using a well-trained therapy dog. In medical settings, AAT has been implemented in
various clinical situations and has been shown to help reduce pain and stress indicators in patients.4
Research into AAT as a non-pharmacological behavior management and anxiety reduction
techniques in dentistry is limited as many publications are surveys5 with a low sample size and are
not conducted in the pediatric and/or dental patient population.2
To explore the effectiveness of non-pharmacological anxiety-reduction approaches, we will
study the effects of animal-assisted therapy (AAT) on pediatric patients undergoing invasive dental
procedures that include an injection. The University of North Carolina has a unique opportunity to
explore animal-assisted therapy because the dental school has a certified therapy dog. Our central
hypothesis is that children who interact with a therapy dog before their dental procedure will have
significantly lower physiologic and subjective responses to stress. We will test this hypothesis by
following aims:

Primary Aim: We will measure the effects of animal assisted therapy on pediatric
patients’ stress levels by analyzing objective physiologic measures (salivary amylase and
cortisol) during invasive dental procedures.
Supplemental Aims: We will measure participants’ heart rate throughout dental visit, will
evaluate patients’ perceptions of pain and anxiety using pre-, intra-, and
post-procedural surveys to assess the patients’ subjective responses to animal-assisted
therapy and will analyze participants’ behaviors using observational coding.
The proposed study will examine the effectiveness of animal-assisted therapy on pediatric
dental patients from a subjective and objective perspective to guide implementation of AAT in
pediatric dental settings for anxious patients.
BACKGROUND AND SIGNIFICANCE:
Dental anxiety (DA) negatively impacts oral health worldwide. A meta-analysis reviewing DA in
patients ages 3-18 years-old found a prevalence of 23.9%.6 Many adults attribute their dental anxiety
to an earlier, traumatic dental experience.3 In a survey of 1,420 subjects, 16.4% adults had dental
anxiety with 50.9% reporting dental anxiety onset in childhood.7 Dental anxiety is linked to avoidance
behavior and an increased pain response during dental procedures.1,2,8 Avoidance behavior can lead
to increased complexity of dental treatments, increased costs and often tooth loss with more
emergency visits, increased probability of infection, and in severe cases, even death. 9 A parent’s
own dental anxiety can also present a barrier to their child’s access to dental care.10
Behavioral management and anxiety control techniques are essential to improving a child’s
experience and to avoid a lifelong fear of dental procedures.11 The American Association of Pediatric
Dentists (AAPD) recommends the use of pharmacological and non-pharmacological techniques to
provide dental care for children with DA.12 Even when regularly and safely used, moderate and deep
sedation as well as general anesthesia pose patient risks including compromise to respiratory drive,
airway reflexes and airway patency, and the cardiovascular system.3,13 For this reason,
pharmacological behavioral management is often met with resistance from parents.14 Moderate to
deep sedation and general anesthesia for anxiety control is also costly for the patient and the
healthcare system. In a review of Medicaid claims in North Carolina from 2011-2015, general
anesthesia was used in 15.8 out of 1,000 cases and cost approximately $16.7 million per
year. Expenditures on general anesthesia for dental procedures continue to increase.15 At this time,
limited methods for non-pharmacological anxiety control exist. A low cost, low risk alternative to
sedation is needed for anxious pediatric dental patients.
Animal assisted therapy (AAT) is a promising option for treating children with DA. AAT is an
intervention that involves a well-trained therapy dog to reduce anxiety. Dogs can sense elevated
stress hormones like glucocorticoids and catecholamines and respond accordingly.4 Data regarding
AAT’s positive effects are encouraging and abundant in medicine. Brief interactions with therapy dogs
have been shown to decrease stress hormones and increase endorphins in adult patients.9 The
positive effects can even be seen in healthcare workers. In one study, healthcare workers who had an
interaction with a therapy dog were shown to have reduced serum cortisol.16
The use of AAT in dentistry is just beginning, though initial data is promising. 4,17–26 In a study of
children who verbalized distress, the presence of the dog decreased their physiological arousal while
waiting for their dental provider.18 In a randomized clinical trial in India, children’s 15-minute
interactions with a therapy dog at a pediatric dental office in the waiting area reduced subjective
stress levels.26 The acceptability of AAT by caregivers has been explored in a survey performed at
Case Western Reserve where their research team found that 90% of caregivers expressed
acceptability of a therapy dog in the pediatric dental setting while 68% expressed a demand for a

therapy dog to be included in part of the child’s treatment.5 Existing dental AAT studies have used
skin temperature, heart rate and blood pressure to quantify effects.18,27 Separately, validated scales
have also been used to assess anxiety level. 28,29 Interventional studies focused on pediatric dental
patients receiving AAT involved non-invasive dental procedures such as sealants and suction
placement (Isodry®).28 Though valuable, the literature is missing a comprehensive, larger study that
evaluates the physiological and emotional impacts of AAT in dentistry.
Currently there are no studies that use observational coding, galvanic skin (sweat) response,
and cortisol and salivary amylase samples to measure the effects of AAT in dental contexts. At this
time, there are no large-scale randomized controlled trials evaluating efficacy of AAT during invasive
dental procedures in pediatric patients. The University of North Carolina at Chapel Hill (UNC-CH) has
a distinctive opportunity to conduct such a study and explore AAT because the dental school has a
trained therapy dog for its graduate pediatric department.
Dentistry is in need of anxiety control measures other than sedation in order to reduce
risk to patients, lower the cost of treatment and increase access to dental care. The pediatric dental
experience may be improved by the implementation of a therapy dog for anxiety, pain and behavior
management. Our investigation will be the first to comprehensively assess physiological and
psychological effects of AAT using a randomized controlled trial with a therapy dog intervention. If
efficacious at anxiety, pain and behavior management, AAT will offer dental providers a non-invasive,
low-risk approach to provide positive dental experiences, with the translational goal of reducing dental
avoidance and its significant negative health sequelae.
EXPERIMENTAL DESIGN AND METHODS:
We have designed a cross-sectional prospective controlled trial assessing whether AAT
(intervention with a therapy dog) impacts physiologic biometrics and perceptions of anxiety, pain and
future expectations during a dental procedure in pediatric patients.
Screening for research participants includes searching the dental school graduate pediatric
clinic schedule for potentially qualifying participants scheduled for operative or restorative dental
treatment. Inclusion and exclusion criteria can be found in Table 1.
Table 1: Inclusion and Exclusion Criteria
Inclusion Criteria
Exclusion Criteria
Ages 7-17, male or female
Fear or allergy to dogs
Patient receiving treatment at UNC Pediatric
Dental Clinic
Non-English and non-Spanish speakers
Parent and participant speak English or
Spanish
Learning disability or a developmental delay
Able to comprehend and follow the
requirement of the study
Medical history that complicates dental
treatment
Frankl Behavioral Scale II, III, or IV
Xerostomia (dry-mouth)
This study has been approved by the UNC IRB (IRB Number: 19-1911; Title: Animal Assisted Therapy’s Effects on Dental
Patients)
The research team calls to interview parents/caregivers of patients for enrollment criteria
(Table 1). If a participant enrolls, he or she is assigned to a random weekday which determines the
therapy animal’s availability and will be either the active control group or the experimental AAT (dog
intervention) group. The research team sets up a Go-Pro camera to film the visit and places the heart
rate monitor (Shimmer or Polar device) on the patient’s wrist in the pediatric clinic’s consultation
room. The participant is asked a standardized set of anxiety scale questionnaires: the Modified Child

Dental Anxiety Survey (MCDAS) and the
Children’s Fear Survey Schedule, Dental
Subset (CFSS-SD). The child also rates
their current pain level using Wong-Baker
FACES (WBS), a numeric scale, and the
visual analog scale (VAS). After the
interview, the AAT intervention or control
(i.e. coloring or sitting in silence) takes
place for 3 minutes. The intervention group
will interact with the therapy dog using a
reproducible, standardized method. The
handler will introduce the dog, and the
participant pets the therapy dog, shakes
her paw, gives her a treat, and then says
goodbye in the clinic’s consultation room.
The control group will color a picture of a
dog (active) or sit in silence (passive) for 3 minutes. C-DART database software will be used to
record patient responses and guide the research visit in a structured manner. Following the
intervention, the child is taken into the treatment room with the heart rate device still on his or her
wrist, collecting objective physiological data. The GoPro camera will be taken into the treatment room,
to provide for simultaneous video and physiological data collection. Salivary samples using salivettes
will be collected at 4 timepoints during the visit, as described in Table 1. See Figure 1 for treatment
visit protocol.
Primary Aim: We will measure the physiologic effects of animal assisted therapy on pediatric
patients’ stress levels. Salivary alpha-amylase (sAA) functions as a digestive enzyme involved in
the breakdown of glycogen and starch as well as part of the immune system by protecting the oral
cavity from harmful microorganisms.30 Salivary alpha-amylase increases in response to stress.31 In a
study of 99 patients undergoing an invasive dental procedure, Jafari et. al presented evidence to
support the dependability and objectivity of using sAA to measure the acute stress response in
patients with dental anxiety.32
Another physiological indicator of stress response that can be measured in the dental setting is
salivary cortisol. The hypothalamic-pituitary-adrenal axis (HPA) is an important aspect of the
endocrine system which leads to release of cortisol from the adrenal glands when the body is subject
to physical or emotional stress.33 As supported by the 2007 meta-analysis by Miller et. al exploring
cortisol levels and stress, the use of salivary cortisol levels is well cited in the scientific literature to be
a validated biomarker for stress.34
To collect a saliva sample, the research team places a salivette in the mandibular vestibule for
5 minutes at the following timepoints:
Table 2: Timepoints for salivary data collection
Timepoint
Description
S1
Baseline (pre-intervention, in consultation room)
S2
Post-intervention (8 minutes after intervention)
S3
8 minutes into the dental procedure
S4
8 minutes after completion of the procedure at the end
of the study visit

Supplemental Aims: We will measure participants’ heart rate throughout dental visit, will
evaluate patients’ perceptions of pain and anxiety using pre-, intra-, and post-procedural
surveys and will analyze participants’ behaviors using observational coding.
The Shimmer 3 GSR+ and Polar are small wearable wrist devices that measure heart rate through
the wrist, with Shimmer 3 GSR+ also measuring sweat response through sensors that are fastened to
the fingers. The Shimmer/Polar device will be connected to the patient during the pre-procedural
interview, dog or control intervention, and procedure, continuously collecting heart rate and/or
galvanic skin response (GSR) data.
Because heart rate is known to reliably increase under acute mental stress, it is widely used in
medical research to evaluate stress response.35 The Galvanic Skin Response (GSR) is a biomarker
that quantifies the small electrical current induced by sweat which is released when the body is under
stress.36 The most significant psycho-activity and concentration of the epidermal sweat glands is on
the sole of foot and the palm of the hand, particularly on the volar surface of the finger tips.36 In a
study completed by Caprara et. al in 2003, GSR was linked to increased dental anxiety in patients
before undergoing a root canal treatment.37
The video of the procedure as well as the heart rate data and GSR from the Shimmer device is
loaded on to an external hard drive. The video will be coded with established behavioral codes using
the Noldus software. The HR and GSR data are reviewed for inconsistencies using MindWare
software. Both software are on a computer located in the bio-behavioral lab (BBL). The salivettes are
transferred in a temperature-controlled container to the BBL where they are analyzed by ELISA for
salivary alpha-amylase and salivary cortisol.
Pre-intervention and post-intervention interviews will include the Child Fear Survey
Schedule-Subset Dental (CFSS-SD), and the Modified Child Dental Anxiety Scale (MCDAS) to rate
anxiety. To rate pain, the Wong-Baker FACES Scale (WBS), a numeric scale, and Visual Analog
Scale (VAS) will also be used. The three pain rating scales will be repeated immediately after the
injection. At the end of the procedures, the research team will repeat the CFSS-SD and the MCDAS
for anxiety. They will also ask the child to rate his or her pain level again using the WBS, numeric
scale, and VAS.
Pictorial representation of pain response, like The Wong-Baker FACES Scale (WBS), are
preferred by children to express their level of pain regardless of age.38 The Modified Child Dental
Anxiety Survey (MCDAS) and the Children’s Fear Survey Schedule, Dental Subset (CFSS-SD) are
valid and reliable questionnaires in rating a child’s anxiety in the dental setting.39
STATISTICAL ANALYSIS PLAN:
To evaluate the values obtained on the various surveys, a RH Row Mean test will be utilized to
compare questions that have Likert scale / ordinal responses and a chi square test will be used for
categorical data. A bivariate analysis will be performed to compare the treatment outcome relative to
the main exposure, which is the presence of the animal assisted therapy. The significance level will
be P < 0.05.

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