UMIN-ICDS Clinical Trial
| Unique ID issued by UMIN | UMIN000062378 |
|---|---|
| Receipt number | R000071386 |
| Scientific Title | An Exploratory Study of Emotional and Psychophysiological Responses to Dental-related Olfactory Stimuli |
| Date of disclosure of the study information | 2026/07/28 |
| Last modified on | 2026/07/28 23:28:20 |
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Basic information
Public title
A study of subjective and physiological responses to dental-related olfactory stimuli
Acronym
Dental Odor Response Study
Scientific Title
An Exploratory Study of Emotional and Psychophysiological Responses to Dental-related Olfactory Stimuli
Scientific Title:Acronym
Dental Odor Psychophysiology Study
Region
| Japan |
Condition
Condition
Not applicable (healthy adults with previous dental treatment experience). Dental fear severity will be assessed using the Dental Fear Survey.
Classification by specialty
| Dental medicine | Adult |
Classification by malignancy
Others
Genomic information
NO
Objectives
Narrative objectives1
To determine whether subjective emotional ratings of dental-related olfactory stimuli differ according to the severity of dental fear.
Basic objectives2
Others
Basic objectives -Others
To evaluate changes in heart rate and electrodermal activity in response to dental-related olfactory stimuli and to investigate their relationship with dental fear, previous dental experiences, anxiety traits, sensory-processing characteristics, and subjective emotional ratings.
Trial characteristics_1
Exploratory
Trial characteristics_2
Developmental phase
Not applicable
Assessment
Primary outcomes
Subjective emotional ratings of each dental-related olfactory stimulus. Numerical Rating Scales (NRS) will be used to assess fear and aversion. The primary analysis will examine the association of ratings for dental-related stimuli with DFS scores and differences between the dental-fear and control groups. Ratings will be obtained immediately after each odor presentation.
Key secondary outcomes
1) Electrodermal activity: changes in skin conductance level, skin conductance responses, or phasic activity from the pre-stimulus baseline during a prespecified post-stimulus time window. 2) Heart rate: changes from baseline during and after odor presentation. 3) Additional subjective ratings, including pleasantness/unpleasantness, liking, intensity, familiarity, odor identification, and arousal. 4) Psychological measures, including the DFS, Dental Anxiety Scale, measures of previous unpleasant dental experiences, anxiety traits, sensory-processing characteristics, and health-related quality of life.
Base
Study type
Interventional
Study design
Basic design
Single arm
Randomization
Non-randomized
Randomization unit
Blinding
Open -no one is blinded
Control
Self control
Stratification
NO
Dynamic allocation
Institution consideration
Blocking
Concealment
Intervention
No. of arms
1
Purpose of intervention
Diagnosis
Type of intervention
| Other |
Interventions/Control_1
Participants will be exposed to a predefined set of dental-related, pleasant, unpleasant, and control olfactory stimuli. Dental-related stimuli include eugenol, guaiacol, resin monomer, and sodium hypochlorite. Pleasant stimuli will include selected aroma, and unpleasant stimuli will include skatole and isovaleric acid. Distilled water or an equivalent minimally odorous stimulus will be used as the control. Each odor will generally be presented for approximately 10 seconds, with an adequate inter-stimulus rest interval. Subjective ratings will be obtained immediately after each presentation, and heart rate and electrodermal activity will be recorded continuously before, during, and after odor presentation.
Interventions/Control_2
Interventions/Control_3
Interventions/Control_4
Interventions/Control_5
Interventions/Control_6
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| 18 | years-old | <= |
Age-upper limit
| 60 | years-old | > |
Gender
Male and Female
Key inclusion criteria
1) Aged 18-59 years at the time of consent; 2) a healthy adult with previous dental treatment experience; and 3) able to understand the study and provide voluntary written informed consent.
Key exclusion criteria
1) Chronic sinusitis, allergic rhinitis, common cold, or another condition affecting olfactory function; 2) use of medication that may affect olfactory, central nervous, or autonomic function; 3) current pharmacological or other treatment that suppresses dental fear; 4) a history of psychiatric disorders; or 5) judged unsuitable by the principal investigator for reasons of safety or data quality.
Target sample size
40
Research contact person
Name of lead principal investigator
| 1st name | Hiroyuki |
| Middle name | |
| Last name | Karibe |
Organization
The Nippon Dental University, School of Life Dentistry at Tokyo
Division name
Department of Pediatric Dentistry
Zip code
102-8159
Address
1-9-20 Fujimi Chiyoda-ku Tokyo, Japan
TEL
03-3261-6524
h-karibe@tky.ndu.ac.jp
Public contact
Name of contact person
| 1st name | Hiroyuki |
| Middle name | |
| Last name | Karibe |
Organization
The Nippon Dental University, School of Life Dentistry at Tokyo
Division name
Department of Pediatric Dentistry
Zip code
102-8159
Address
1-9-20 Fujimi Chiyoda-ku Tokyo, Japan
TEL
03-3261-6524
Homepage URL
h-karibe@tky.ndu.ac.jp
Sponsor or person
Institute
Nippon Dental university
Institute
Department
Personal name
Hiroyuki Karibe
Funding Source
Organization
Scientific Research from the Japan Society for the Promotion of Science
Organization
Division
Category of Funding Organization
Japanese Governmental office
Nationality of Funding Organization
Other related organizations
Co-sponsor
Name of secondary funder(s)
IRB Contact (For public release)
Organization
The Ethics Committee of Nippon Dental University, School of Life Dentistry
Address
1-9-20 Fujimi Chiyoda-ku Tokyo
Tel
03-3261-8311
ndu-rinri@tky.ndu.ac.jp
Secondary IDs
Secondary IDs
NO
Study ID_1
Org. issuing International ID_1
Study ID_2
Org. issuing International ID_2
IND to MHLW
Institutions
Institutions
日本歯科大学生命歯学部小児歯科学講座研究室（東京都）
Other administrative information
Date of disclosure of the study information
| 2026 | Year | 07 | Month | 28 | Day |
Related information
URL releasing protocol
Publication of results
Unpublished
Result
URL related to results and publications
Number of participants that the trial has enrolled
Results
Results date posted
Results Delayed
Results Delay Reason
Date of the first journal publication of results
Baseline Characteristics
Participant flow
Adverse events
Outcome measures
Plan to share IPD
IPD sharing Plan description
Progress
Recruitment status
Preinitiation
Date of protocol fixation
| 2025 | Year | 06 | Month | 06 | Day |
Date of IRB
| 2026 | Year | 03 | Month | 23 | Day |
Anticipated trial start date
| 2026 | Year | 07 | Month | 30 | Day |
Last follow-up date
| 2026 | Year | 10 | Month | 31 | Day |
Date of closure to data entry
| 2026 | Year | 10 | Month | 31 | Day |
Date trial data considered complete
| 2026 | Year | 11 | Month | 15 | Day |
Date analysis concluded
| 2026 | Year | 11 | Month | 30 | Day |
Other
Other related information
This is a single-center exploratory study in which healthy adults will be exposed to multiple olfactory stimuli for research purposes, with repeated measurements of subjective emotional ratings, heart rate, and electrodermal activity. All participants will undergo the same standardized olfactory stimulus protocol. Participants will not be assigned to intervention groups. Instead, they will be categorized into dental fear and control groups during statistical analysis according to their Dental Fear Survey (DFS) scores (cut-off value: 52, corresponding to the Japanese population mean + 1 standard deviation). Although both subjective and physiological outcomes will be collected in this study, they address different research objectives and analytical hypotheses and may therefore be reported in separate peer-reviewed journal articles.
Management information
Registered date
| 2026 | Year | 07 | Month | 28 | Day |
Last modified on
| 2026 | Year | 07 | Month | 28 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000071386
