Can a Low-threshold Check-up Motivate Older People to Schedule a Dental Visit? A Randomized Controlled Trial
Phase: NA
Conditions: Oral Disease
Sponsor: University Ghent

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Can a low-threshold check-up motivate older people 
to schedule a dental visit? 
A Randomized Controlled Trial 
 
 
NCT:  
 
 
 
 
 

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Protocol 
Administrative information 
The numbers in brackets [ ] are referring to the items on the SPIRIT 2013 Checklist.  
Titel [1] 
Can a low-threshold check-up motivate older people to schedule 
a dental visit? A Randomized Controlled Trial 
- 
Superiority trial 
- 
Parallel study 
Trial registration [2a, 2b] 
 
Protocol version  
Version 1.0, 25/03/2024 
Funding  
Funded by the Flemish Agency for Care and Health (project-
number VLA.DIV.2021.0090.01) 
Elke Ghyllebert 
T 02 553 29 85 
E elke.ghyllebert@vlaanderen.be 
Koning Albert II-laan 35 bus 33, 1030 Brussel 
Roles and responsibilities [5a 
en 31b] 
Aster De Vleeschauwer1 
Ellen Baele1 
Natalie Hoste2 
Louise Poppe2 
Roos Colman3 
Peter Pype2 
Fien Mertens2 
Barbara Janssens1 
 
1Department of Oral Health Sciences, Ghent University, Belgium 
2Department of Public Health and Primary Care, Ghent University, 
Belgium 
3Biostatistics Unit, Faculty of Medicine and Health Sciences, Ghent 
University, Belgium 
 
- 
BJ conceived of the study. 
- 
ADV, LP en BJ initiated the study design and EB, NH, PP and 
FM contributed to refinement of the study protocol. 
- 
ADV will perform collection, management, analysis and 
interpretation of the data. 
- 
BJ is grant holder.  
- 
RC and LP provided statistical expertise in clinical trial 
design and analysis. 
- 
ADV, EB, NH, LP, PP, FM and BJ will approve the final 
manuscript. 
Name and contact 
information for the trial 
sponsor [5b] 
There was no sponsor. 
The funder had no role in the study design; collection, 
management, analysis and interpretation of the data; the writing 
of the report or the decision to submit the results. 

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Role of study sponsor and 
funders, if any, in study 
design [5c] 
Composition, roles and 
responsibilities of the 
coordinating center, steering 
committee, endpoint 
adjudication committee, 
data management team and 
other individuals or groups 
overseeing the trial, if 
applicable [5d] 
The members of the Gerodent PLUS-research project (ADV, EB, 
NH, LP, PP, FM and BJ)  and RC will advise on study design, 
interpretation of the data, writing of the report and the decision to 
submit the report for publication. 
 
A stakeholder group was formed. They will oversee the project and 
provide advice according to their expertise. Members of this group 
are: 
- 
Vlaams Instituut Mondgezondheid (Gezonde Mond) 
- 
Logo Limburg on behalf of all Flemish Logo’s 
- 
Expertisecentrum Dementie Paradox 
- 
Vlaams Instituut Gezond Leven 
- 
VZW Zorg-Saam ZKJ 
- 
Woonzorggroep GVO 
- 
Vivel 
- 
ELZ Scheldekracht vzw 
- 
ELZ RITS 
- 
Logo Midden West-Vlaanderen 
- 
Zorgband Leie en Schelde 
 
Introduction 
[6a] Background and rationale 
People are living longer, therefore the population is aging. By 2061, the number of people older than 
55 years in Belgium will increase by a third to 35.4% of the total population. The number of people 
older than 85 is expected to double (1). Thus, healthy ageing is more crucial than ever to avoid 
straining the health care system. 
The World Health Organization (WHO) defines healthy ageing as “the process of developing and 
maintaining the functional ability that enables wellbeing in older age”. (2) Chan's study from 2023 
provides a good summary of the impact of oral health on healthy aging (3). Poor oral hygiene causes 
caries and periodontitis, resulting in a high level of tooth loss in older generations. Older people are 
also more susceptible to xerostomia or oral cancer (4). The effects of poor oral health extend beyond 
the mouth and have an impact on overall health e.g. the risk of aspiratory pneumonia-related death 
(4). Poor oral health is also associated with cardiovascular disease and diabetes (5). Additionally, 
tooth loss, xerostomia and oral cancer can cause chewing and swallowing problems, which can lead 
to reduced nutritional uptake (6).  Furthermore, the psychological impact of oral health should not 
be ignored. Poor oral health can lead to pain, feelings of shame and reduced social contact. All of 
these have an impact on the quality of life of older adults (7).  
Despite the fact that oral health is an important part of overall health, oral diseases are the most 
prevalent condition worldwide (8). Chan's 2021 systematic review reports a median untreated caries 
prevalence of 46% in Europe in older adults aged 60 years or above (9). Research from 2016 reported 
poor oral health among frail elderly people in Belgium. There was a high treatment need, and oral 
health was distressing (10).  

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Most oral diseases are preventable by maintaining good daily oral hygiene and periodic professional 
care (11-13). However, dental attendance is low in older adults. Research in Belgium from the period 
2019-2021 showed that only 34% of the population received preventive oral care and 26% of the 
population did not go to the dentist at all (14). Likewise, a recent oral health consumption analysis 
indicated that 41.7% of adults over 65 years in Flanders in the period 2020-2022 had no contact with 
the dentist at all and only 32.2% of them went for regular dental checkups. Once more, it was 
confirmed in our own interview studies with older people that the majority did not have a regular 
dental check-up. The main reasons for not seeking dental care are bad previous experiences, not 
knowing its importance, edentulousness, fear of the dentist, perceived costs and practical issues in 
reaching a dental office (15-17).  
There is little research on the effect of oral screening campaigns for improving oral health in older 
people. Therefore, the aim of this study is to investigate the effect of a low-threshold contact with an 
oral health professional, including an oral health examination, on dental attendance of older people 
(65 years of age or older). 
[6b] Explanation for choice of comparators 
Our interview studies and a review of literature showed that older people are not aware of the 
importance of regular dental attendance and don’t always have enough skills to schedule a dental 
visit and find a new dentist after retirement of their previous one. (16, 18) 
The intervention group will be provided with tools to facilitate dental contact and will be informed 
about the importance of regular dental visits. Participants are given the opportunity to receive an 
oral examination. Afterwards, each participant will receive brochures with oral hygiene instructions 
to take home. Participants will receive information about any identified oral pathology. A referral 
letter for the dentist and a report for the general practitioner will also be prepared to increase social 
influence. If the participant doesn’t have a dentist, the participant will receive a list of contact 
information for dentists in the area. 
In the control group, no oral examination will be performed. However, participants will be given a list 
of nearby dentists and flyers with oral hygiene instructions. 
In this way, we want to find out whether the presence of a dental professional with tailored advice is 
crucial to motivate an elderly person to good oral care. 
[7] Objectives 
The objective is to determine whether offering a low-threshold oral check-up to older adults, 
including oral health counselling, referral and report letters and a list of nearby dentists, results in a 
higher likelihood of contacting a dentist in the following 4 months compared to a control group that 
only received general oral health promotion leaflets and a list of nearby dentists.  
Research hypothesis 
We expect that elders who had a low-threshold oral check-up and received information about their 
oral situation will be more likely to contact a dentist. 
[8]Trial design 
This trial is designed as a randomized, controlled, non-blinded, superiority trial with two parallel 
groups. Randomization will be performed as block randomization with a 1:1 allocation. For practical 
reasons, each block will consist of 8 to 12 people. 

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Methods: Participants, interventions and outcomes 
[9] Study setting 
The study will be conducted within two specific regions in Flanders, Belgium. All service centers 
within the primary care zones RITS and Scheldekracht will be invited to participate in the study. 
Organizations focusing on older people will also be contacted to spread our call for participation in 
the study.  
[10] Eligibility criteria 
Older people are included when they meet the following criteria: they are 65 years of age or older, 
home-dwelling within the selected regions, they are Dutch speaking, and they did not have a dental 
check-up in the last 12 months. (19) By home-dwelling, we mean anyone who does not reside 24/7 in 
a residential care facility. If it concerns a couple, only one person can participate. Participants should 
have sufficient cognitive ability to answer the questions. If we ask the questions and find that the 
older person is unable to answer them adequately due to cognitive impairment, he or she will not be 
included in the study. 
[11a] Interventions 
After filling out the interview based questionnaire (see Appendix), the participants will be 
randomized between the control group and the intervention group. This will ensure that there are 
equal numbers of frail people in both groups. 
The participants in the intervention group will receive an oral examination. Subsequently, 
information about any identified problem will be given. Lastly, participants will receive a referral 
letter for their dentist and a report for the general practitioner. If the participants don’t have a 
regular dentist, they will also be given a list with contact information of dentists in the area. 
Both the intervention and the control group will receive a flyer with oral hygiene instructions 
adapted to their needs and if necessary a list with contact information of dentist in the area. These 
flyers are evidence-based brochures compiled by the Flemish institute of oral health ("Gezonde 
Mond") on performing good oral hygiene. 
[11b] Interventions - modifications 
If an elderly person is randomized into the intervention group but refuses to have on oral 
examination, this will be noted. 
If an elderly person in the control group asks for an oral examination because of a particular 
problem, the elderly person will be given the advice to contact a dentist. 
[11c] Interventions – adherence 
At the end of the initial contact, participants will be reminded that they will receive a phone call after 
4 months. All participants will receive a pen with the logo of Gerodent PLUS as a gift. 
[11d] Interventions – concomitant care 
No concomitant care is prohibited to the participants. The intent of the study is to examine whether 
older people find access to regular care due to our intervention. 
[12] Outcomes 
Primary Outcome Measures 
Participants will be contacted 4 months after the initial contact by telephone to ask if they contacted 
a dental professional since the first contact. We will make four attempts to contact them, two in the 

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morning and two in the afternoon. Contact information of partner or caregiver will also be included, 
in case the participant cannot be reached. 
If the older person has contacted a dental professional within 4 months of our initial contact, then 
this is considered a success. Due to a shortage of dental professionals in Flanders, there is often a 
fairly long waiting period before a patient can get an appointment. In addition, many professionals 
have implemented a patient stop. So we want to give the elders enough time to find a dental 
professional. Differences in proportions will be reported. 
 
Intervention group 
Control group 
Contacted a dentist within 4 
months 
 
 
Not contacted a dentist within 
4 months 
 
 
 
 

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[13] Participant timeline 
 
 
 
 
Selecting centra located in the chosen region
Sending invitations to these centra asking them to 
participate
Informed consent for questionnaire
Questionnaire
Frailty Assessment
Randomization
Allocated to the Intervention Group
Informed Consent for Screening
Screening of oral status
Giving information about 
identified problem
Giving referral letter for 
dentist and report for family 
doctor
Giving a flyer with oral 
hygiene instructions and a list 
of nearby dentists
t = 4 months 
Telephone questionnaire
Allocated to the Control Group
Flyer with oral hygiene instructions and a list of 
nearby dentists
t = 4 months
Telephone questionnaire

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[14]  Sample size 
We expect to activate 30% of the participants in the intervention group; in the control group, we 
expect a maximum of 10%. To detect a mean difference of 20% with equal allocation to both groups 
would require 129 persons in total. To allow for 33% drop-out, 194 persons will be recruited. 
 
[15] Recruitment 
Service centers within the RITS and Scheldekracht primary care zones will be asked if they are willing 
to participate in the study. A date will be arranged with the interested centers when the study can 
take place in their facilities. 
Organizations and other local initiatives will also be contacted to spread our call for participation in 
the study. Older people will be able to sign up at a participating service center to participate in the 
study. 
Furthermore, home nursing and home care service organizations in the region have agreed to assist 
with participant recruitment. 

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Methods: Assignment of interventions 
Allocation 
[16a] Sequence generation 
Participants will be randomly assigned to either control or intervention group with a 1:1 allocation. 
Randomization will be stratified by frailty. Random permuted blocks will be created using SAS v9.4 
with variable sizes to avoid that the treatment allocation can be predicted. For practical reasons 
block size will vary between 8 and 12. 
[16b] Allocation concealment mechanism and [16c] Implementation 
A randomization list (prepared by RC) will be processed in REDCap by a HIRUZ staff member. 
Screeners will not have access to this list. Allocation concealment will be ensured as the REDCap-
program will not release the randomization code until the questionnaire was completed. 
[17] Blinding (masking) 
This study is an open trial. The researchers at timepoint 1 are not blind to allocations. Participants in 
the control group will not be informed by the researchers that other participants might receive an 
oral examination. Participants in the intervention group will be told that due to an excess of time, 
they will also receive an oral examination. There is no procedure for unblinding needed. 
At timepoint 2 the person will be contacted again by a different researcher than the researcher of 
the first contact, that way the researcher does not know in which group the participant was assigned. 
Methods: Data collection, management and analysis 
Data collection methods 
[18a] Plans for assessment and collection of outcomes 
The study will be piloted outside the region where the study takes place. Researchers PM and TC will 
be trained for screening of the oral status by researcher ADV. Interrater reliability will be calculated 
(20). Piloting will not be terminated until sufficient agreement is established. 
 No x-rays will be taken due to ethical concerns. Examiners will use a head lamp, a mouth mirror and 
periodontal probe for the oral examination. Denture plaque will be evaluated using methylene blue 
staining. 
A script was integrated into the questionnaire on REDCap. It will not only display the questions, but 
will also display reminders so that no part of the survey can be forgotten (see Appendix). For 
example, researchers will have to check off that the informed consent form was signed or whether 
referral letters were completed and given to the participants. After each section of the 
questionnaire, the researcher will need to confirm that all questions in this section were completed.  
Using REDCap, a calendar will be created automatically showing when the participants should be 
called for the questionnaire at timepoint 2. 
[18b] Plans to promote participant retention and complete follow-up 
- 
At the end of the initial contact, participants will be reminded that they will be called again 4 
months later. Contact information for a partner, child or caregiver will also be noted. If a 
participant indicates they prefer to receive a letter, the home address will be noted. 
- 
All participants will receive a pen with the logo of Gerodent PLUS as a gift. 
- 
A 33% drop-out rate was taken into account when calculating the sample size. 

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- 
Refusal of the oral examination will be noted. However, since we are working from the 
intention to treat principle, the participant will remain in the intervention group. 
[19] Data management 
Data will be collected exclusively electronically through REDCap. REDCap is a secure web application 
for building and managing online surveys and databases. The type of activity that an individual user 
may undertake is regulated by the privileges associated with his/her account. 
Once all data are collected, a copy of REDCap will be kept on the secure servers of Ghent University. 
Only members of the research team will have access to the data. If needed, data will be transferred 
using a Secure File Transfer platform, Belnet Filesender. 
Statistical methods 
[20a] Statistical methods for primary and secondary outcomes 
Two weeks after the last telephone questionnaire was scheduled, we will end the data collection and 
the statistical analysis will be executed. The intervention group will be compared against the control 
group for having consulted a dentist within 4 months after the initial contact. Differences in 
proportions will be reported, logistic regression models will be used. 
[20b] Methods for additional analyses (e.g. subgroup analyses) 
Subgroup analyses will be purely exploratory: 
- 
Impact of age on outcome 
- 
Impact of gender on outcome 
- 
Impact of education on outcome 
- 
Impact of financial situation on outcome 
- 
Impact of frailty on outcome. 
- 
Impact of whether participant is dentate or edentulous on outcome. 
- 
Impact of whether participant experienced oral problems the previous 6 months on 
outcome. 
[20c] Methods in analysis to handle protocol non-adherence and any statistical methods to 
handle missing data 
All randomized participants will be included in the “intention to treat”-analysis. This means that a 
participant allocated to the intervention group, who refuses an oral examination will remain in the 
intervention group. 
If we cannot reach a participant at timepoint 2, the specified proxy will be contacted. If it appears 
that the participant has since died, they will be considered as drop-out. If it appears that the 
participant is not available (e.g., due to hospitalization), we will submit the questionnaire to the 
proxy. When we cannot reach an individual at all, we will address this missing data by applying 
multiple imputation per randomization arm. We will check for having natural teeth and when the last 
dental visit occurred, but this is not an exhaustive list. 

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Methods: monitoring 
[21] Data monitoring 
Since this study has no major safety concerns, no data monitoring committee will be composed. No 
interim analysis will be conducted. 
[22] Harms 
An adverse event refers to an unwanted side-effect during the study, which may or may not be 
causally related to the intervention or other aspects of participation in the study. We expect no such 
events to happen because of the design of the intervention. However, participants are informed that 
when an injury does occur, they may contact the investigator or a member of the research team. 
Contact information is included in the informed consent form. 
[23] Auditing 
There will be no auditing. 
Ethics and dissemination 
[24] Research ethics approval 
This study was approved by an independent Medical Ethics Committee affiliated with Ghent 
University Hospital and Ghent University. The study is conducted according to the guidelines for good 
clinical practice (ICH/GCP) and the Declaration of Helsinki established to protect people participating 
in clinical studies. (Reference number ONZ-2023-0350). Written informed consent will be obtained 
from all the participants. 
Can we contact the participant?
Yes
Submit telephone questionnaire to participant
No
Can we contact a proxy?
Yes
Is the participant available?
Yes
Submit telephone questionnaire to participant
No
Due to death of the participant: drop-out of the study
Due to illness: submit telephone questionnaire to proxy
No
Multiple Imputation

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[25] Protocol amendments 
Any modification to the protocol of the study will need a new approval by the Medical Ethics 
Committee, an amendment will be requested. The decision to amend the protocol will be discussed 
within the research team. 
[26] Consent or assent 
The informed consent forms [32] were approved by the Medical Ethics Committee affiliated with the 
Ghent University Hospital and Ghent University. The forms are addressed to the elderly person living 
at home. The participants should read the informed consent forms thoroughly and discuss them with 
the researcher. After all questions have been answered and upon agreement, the participant should 
sign the forms in the space provided. 
The informed consent form requests the participant's permission to use his pseudonymized data for 
future scientific research in the same/similar research domain. 
[27] Confidentiality 
All the data will be collected pseudonymized. Each participant will be given a coded identification 
number. The key will be kept on a secured server of UGent to which only researchers of the 
Gerodent PLUS project will have access. The informed consent forms will be stored separately from 
study participants records identified by code number. 
The informed consent form requests the participants permission to share the results of the oral 
examination with the family doctor or dentist. A referral and report letter will be given to the 
participant for these professionals. 
Raw data will not be shared with members outside of the Gerodent PLUS-research team.  
[28] Declaration of interests 
The researchers declare that they have no competing interests. 
[29] Access to data 
Only members of the Gerodent PLUS-research team will have full access to the data. Raw data will 
not be shared with the sponsor or with journals. 
[30] Ancillary and post-trial care 
No disadvantages are expected for elderly people participating in this study; therefore no 
arrangements are made for ancillary care and post-trial care. 
[31] Dissemination policy 
Results of this study will be published and will be communicated to the Flemish Government. No 
professional writers will be used. 
No later than 3 years after the collection of the final results, a description of the trial methods 
(including the protocol), deidentified data and all analyses will be shared upon request. 

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Appendices 
[32] Informed consent materials 
ICF – questionnaire 
 
 

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ICF – oral examination 
 

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[33] Biological specimens 
No biological specimens will be collected.

 
 
 
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