# A Tele-detection and referral pAthways model for early childhood cariEs control- a protocol for a randomized factorial study: the TRACE study

Nourhan Aly, Mona El Kashlan, Nicolas Giraudeau, Maha El Tantawi

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Nourhan Aly, Mona El Kashlan, Nicolas Giraudeau, Maha El Tantawi. A Tele-detection and referral pAthways model for early childhood cariEs control- a protocol for a randomized factorial study: the TRACE study. BMC Oral Health, 2024, 24 (1), pp.934. 10.1186/s12903-024-04706-8. http://dx.doi.org/10.1186/s12903-024-04706-8

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# A Tele-detection and referral pAthways model for early childhood cariEs control- a protocol for a randomized factorial study: the TRACE study

Nourhan M. Aly¹*, Mona K. El Kashlan¹, Nicolas Giraudeau² and Maha El Tantawi¹

**Abstract**

**Background** Early childhood caries (ECC) is one of the most common childhood diseases affecting the primary teeth of children younger than 6 years of age. ECC progression can be reversed in the early stages although these lesions often go undetected. New approaches are needed to detect oral diseases at an early stage when they can be better controlled. The aim of the study is to assess the effectiveness of ECC tele-detection methods combined with referral pathways with and without user fee removal in controlling ECC.

**Methods** A randomized factorial trial will be used to compare two tele-dentistry detection methods for ECC (intraoral camera and smartphone camera) and two referral pathways (user fee removal versus conventional care). The study will recruit children younger than 6 years of age in marginalized communities in Alexandria, Egypt. The primary outcome is the percentage of teeth receiving indicated care, while the secondary outcomes are the oral health-related quality of life, acceptance of teledentistry by dentists, procedure time, and child cooperation. Two-way analysis of variance will be used to assess the effect of the two factors as between group variables on the outcomes after 6 and 12 months. The interaction between detection methods and referral pathways will also be assessed, and the effect of confounders will be controlled in a multivariable linear regression model.

**Discussion** The findings of this study have the potential to inform clinical practice and oral healthcare policies for ECC management. Successful tele-detection and referral pathways could be integrated into oral healthcare systems, leading to improved oral health outcomes for children.

**Trial registration** The trial has been registered on [ClinicalTrials.gov](https://ClinicalTrials.gov) in August 2023 (initial release) ID: NCT06019884.

**Keywords** Teledentistry, Early childhood caries, Caries detection, Prevention, Caries assessment spectrum and treatment

<footnote>*Correspondence:
Nourhan M. Aly
nourhan.moustafa@alexu.edu.eg; nourhanovic@gmail.com
¹Department of Pediatric Dentistry and Dental Public Health, Faculty of Dentistry, Alexandria University, Alexandria University, Champollion St., Azarita, Alexandria 21527, Egypt
²CEPEL, CNRS, University of Montpellier, Montpellier 34090, France</footnote>
## Background

Early childhood caries (ECC) is the presence of any tooth with untreated caries, filling or missing due to caries in children younger than 6 years of age [1]. It is one of the most common childhood diseases affecting children in this age and is a major public health problem in lower income countries and underserved populations [2]. ECC impacts children's health and wellbeing [2], quality of life, growth, development [2], productivity [3], and economic condition [4]. Untreated ECC can progress to severe stages that require complex and costly treatment under general anesthesia (GA) which poses high risks for children and burden on families, with considerable cost for healthcare systems. Data from the Institute of Health Metrics and Evaluation show that Egypt has the greatest number of prevalent cases of untreated caries in primary teeth among the Middle East and North African (MENA) countries reaching 9.1 million children [5]. This high number of affected children may be attributed to the large population size which is the greatest in the region [6], and to modest levels of oral health literacy [7].

ECC is reversible at early stages although early-stage lesions often go undetected [8]. New approaches are needed to detect ECC lesions at an early stage when they can be prevented, reversed, or arrested. Digital technologies reduce the time to screen and refer children to preventive care, allow underserved populations to be reached, and, on the long run, reduce the cost of dental care [9]. Teledentistry systems proliferated during the COVID-19 pandemic [10]. A mobile caries detection system consists of a camera to record intraoral structures and a laptop to transmit the videos from remote locations over the internet via a secure server to protect patients' data. Trained clinicians in a central facility can remotely identify caries at an early stage when preventive care can control the disease. Evidence supports the accuracy of intraoral cameras with florescent light for caries detection in adults, and the feasibility of using them with large numbers of patients in public healthcare facilities including French prisons [11, 12]. Also, research suggests the possibility of using smartphones to photograph intraoral structures as a low-cost alternative to intraoral cameras [13–16]. Smartphones would be suitable to low-resource settings like Egypt which is a lower middle income country [17]. However, scarce data are available about the use of teledentistry in young children to detect caries at an early stage and refer lesions for care [18].

Several caries assessment systems exist, among which is the Caries Assessment Spectrum and Treatment (CAST) which allows the detection of the whole caries spectrum starting from no caries, to early and advanced carious lesions [19]. CAST enables oral healthcare providers to develop proper preventive and treatment plans. Also, the CAST scores combine criteria of the ICDAS II, PUFA/

pufa, and DMFT/dmft indices, and this allows for calculation of the DMFT/ dmft score from the CAST scores [19, 20]. CAST has been used in several studies of preschool children and its acceptability has been tested in different cultures and age groups [21–24]. Using CAST to assess the extent of caries allows children with lesions that can be reversed to be referred to preventive care, thus reducing the need for invasive treatment. CAST quantifies the distribution of children along the disease spectrum and thus helps understand the predominance of cases at different disease stages to plan for care provision.

The International Caries Classification and Management System (ICCMS) was developed by CariesCare International Group to guide dentists to manage caries [25, 26]. The system categorizes patients into two groups: those at lower risk of caries and those at higher risk [25]. The higher risk group includes children who have recent caries experience, active lesions, and lack caries protective factors like regular toothbrushing, access to fluoridated water, and regular dental care [26]. The guidelines recommend at least twice-yearly application of professional fluoride application to manage ECC in high-risk children [27, 28]. The prevalence of regular toothbrushing and dental visiting is low among Egyptian children which would place them in the ICCMS higher risk category [29–31]. Professional fluoride application to young children at higher ECC risk differs from the standard of care that currently exists in the public sector facilities in Egypt. In these settings, most teeth with ECC are extracted because delayed detection and management allow the disease to progress to an advanced stage [32]. Early ECC detection followed by professional fluoride application allow caries arrest, prevention of dental pain, reduction of treatment costs, with a higher likelihood that primary teeth would remain in the oral cavity till normal shedding with no need for invasive procedures under general anesthesia.

Conditional cash transfer (CCT) programs represent a strategy to improve healthcare access and outcomes, particularly in low- and middle-income countries [33]. These programs offer financial incentives to individuals or families based on specific conditions, such as attending healthcare services, immunizations, or regular check-ups. By tying cash transfers to these health-related behaviors, these programs aim to increase healthcare utilization among vulnerable populations, improve health awareness and preventive care, and ultimately enhance health outcomes [33–35]. CCT programs have the potential to promote preventive dental care, especially in underserved communities. By incentivizing regular dental check-ups, oral hygiene practices, and preventive measures such as fluoride applications, CCT programs can effectively reduce oral health inequalities. These programs not only alleviate financial barriers that often deter
individuals from seeking dental care, but also promote
awareness about the importance of preventive dental ser-
vices [36, 37]. User Fee Removal (UFR) is a related pro-
grams/ intervention using financial incentives to modify
health behaviors. In UFR, the fees to access healthcare
are removed thus addressing the financial barrier against
healthcare utilization [35]. This approach aligns with the
capability domain of the COM-B (capability, opportunity,
and motivation) framework for behavior modification
particularly in a lower-middle income country like Egypt
[38]. UFR was shown to positively impact healthcare use
although its effect on oral healthcare utilization has not
been assessed [35].

The aim of the current study is to compare the effec-
tiveness of two factors on improving clinical and patient-
reported oral health outcomes in young children. The
two factors are (1) tele-detection of ECC using intra oral
camera or smartphone, and (2) referral pathways includ-
ing referral with UFR and conventional referral. The null
hypothesis of the study is that there are no significant
differences in clinical or patient reported oral health out-
comes between different ECC tele-detection methods or
referral pathways.

Methods

Study design

A randomized factorial trial will be used to compare the
two tele-detection methods for ECC and the two referral
pathways (Fig. 1). The allocation ratio is equal. The proto-
col followed the reporting guidelines of Standard Proto-
col Items for Clinical Trials (SPIRIT) [39] and Reporting
Factorial Trials (RAFT) [40]. Factorial trials are designed
to evaluate multiple interventions in the same trial with-
out the need to increase the sample size. Factorial trials
have adequate power to estimate the main effects and
interactions of interventions. Understanding whether
and why interactions occur facilitate the appraisal of the
study design and conclusions [40, 41].

Study setting

The study will be conducted in settings served by the
outreach and community service programs arranged by
Alexandria University and the Ministry of Health (MoH)
for marginalized communities in Alexandria, Egypt.

Participants and sampling

Children under 6 years old will be invited to participate
if their parents/ legal guardians consent to their partici-
pation (Appendix 1). Children with mixed or permanent
dentitions, uncooperative children, those who require
treatment under GA, and those who have physical or
intellectual disabilities will be excluded.

Interventions

The factorial trial compares different methods of ECC
tele-detection and referral pathways as follows:

ECC tele-detection

**Group 1** will use C50 Full HD intraoral camera with fluo-
rescence (Acteon group, Mérignac, France) to videotape
the intra oral structures [42]. The camera has selective
chromatic amplification to record intraoral structures
in the form of videos and/or photos using four modes,
Daylight, Daylight+, Perio and Caries modes. These
modes can differentiate the color of tissues to provide a
reliable diagnosis. The camera will be used in a systemic
sequence to video-record intraoral conditions in both
arches. The intraoral camera will be connected to a lap-
top screen, and the captured videos will be transferred to
an electronic platform.

**Group 2** A smartphone camera (Samsung Galaxy A24) will be used as a low-cost electronic system to photograph the intra oral structures. The smartphone has a triple rear camera setup consisting of a 50 MP primary camera, a 5 MP ultra-wide-angle lens, and a 2 MP depth sensor [43]. Children will be seated on a chair, with the smartphone positioned in front of the oral cavity, without cheek retractors or intraoral mirrors, to scan the upper and lower jaws. The focus will be adjusted, and the inbuilt flash will be used to obtain clear and sharp images. Four pictures will be taken per arch (right side, front, left side, and occlusal views) in a systematic sequence. The photos will be transferred to the electronic platform as in Group I.

After tele-detection, the videos and/ or photos will be
transmitted through the electronic platform to a cen-
tral database for the detection of ECC by the researcher
(NMA). Identification of ECC stages is based on the
CAST index which will be conducted at baseline [19].
The CAST index hierarchically describes the full spec-
trum of caries from absence of caries, to sealants and
treatment restoration, carious lesions with complica-
tions including pulp exposure, abscess/ fistula, and tooth
loss using different codes (Table 1). Codes 0–2 represent
“healthy”, code 3 indicates “pre-morbidity”, codes 4–5
indicate “morbidity”, codes 6–7 indicate “serious morbid-
ity”, and code 8 indicates “mortality” [19–21].

Referral pathways

The teledentist will document the results of tele-detec-
tion in a report and refer the child with the report to
one from a set of pre-identified treating dentists based
on location and availability. The date and location of the
appointment will be recorded, and the child's parent or
guardian will be informed about them. (Fig. 2)

The children will have three scheduled preventive den-
tal appointments at baseline, at 6 and 12 months, during
<figure><img src="image_3.png" /><figcaption>**Fig. 1** Flowchart of the study design</figcaption></figure>

<table><caption>**Table 1** CAST index criteria</caption><thead><tr><td>Characteristic</td><td>Code</td><td>Description</td><td>Concept of health</td></tr></thead><tbody><tr><td>Sound</td><td>0</td><td>No visible evidence of caries</td><td>Healthy</td></tr><tr><td>Sealed</td><td>1</td><td>Pits and/or fissures are at least partially sealed</td><td></td></tr><tr><td>Restored</td><td>2</td><td>A cavity is restored with a restorative material</td><td></td></tr><tr><td>Enamel</td><td>3</td><td>Distinct visual change in enamel only with or without localized enamel breakdown</td><td>Eversible<br>Pre-morbidity</td></tr><tr><td>Dentin</td><td>4</td><td>Internal caries-related discoloration in dentin visible through enamel and may not exhibit a visible enamel breakdown</td><td>Morbidity</td></tr><tr><td></td><td>5</td><td>Distinct dentin cavitation with intact pulp chamber</td><td></td></tr><tr><td>Pulp</td><td>6</td><td>Involvement of the pulp chamber.</td><td>Serious<br>Morbidity</td></tr><tr><td>Abscess/fistula</td><td>7</td><td>A pus containing swelling or pus releasing sinus tract related to tooth with pulp involvement</td><td>Morbidity</td></tr><tr><td>Lost</td><td>8</td><td>The tooth has been extracted due to caries</td><td>Mortality</td></tr></tbody></table>
<figure><img src="image_4.png" /><figcaption>**Fig. 2** Schematic flow diagram of the study protocol</figcaption></figure>

<table><caption>**Table 2** Factorial Design Experimental conditions</caption><thead><tr><td>Experimental conditions</td><td>Tele-detection</td><td>Referral pathways</td></tr></thead><tbody><tr><td>1</td><td>Intra oral camera</td><td>Conventional referral</td></tr><tr><td>2</td><td>Intra oral camera</td><td>User fee removal</td></tr><tr><td>3</td><td>Smart phone</td><td>Conventional referral</td></tr><tr><td>4</td><td>Smart phone</td><td>User fee removal</td></tr></tbody></table>

which topical sodium fluoride varnish will be applied to both arches.

Then, each child will be assigned into different care need categories based on the CAST codes including [25, 26]:

1. Oral hygiene instructions (in addition to the sodium fluoride varnish applied to all children). Lesions in CAST codes 3 can be reversed and those with CAST codes 4 or 5 can be arrested using topically applied fluoride varnishes [44].

2. Restorative treatment for CAST codes 4 and 5 to be confirmed by the treating dentist [44].

3. Advanced care including pulp therapy for CAST code 6 to be confirmed by the treating dentist [44].

4. Other care needed for CAST codes 7 and 8 in addition to other non-caries existing conditions [44].

The children will be further classified into (Fig. 2):

**Subgroup A (UFR)** where the child's parent/legal guardian will receive cash to cover treatment fees and transportation cost after attending the preventive dental visit. The child will receive complete dental care based on the categories indicated above [16, 17].

**Subgroup B (conventional referral)** where children will be referred without receiving cash following the current standard of care in dental clinics in the public sector in Egypt. Care is planned by the receiving/ treating dentist, based on available resources, and hospital/clinic policies. The screening/ sending dentist will inform the family about the oral health condition/s, estimated treatment costs and available clinics that offer the required care.

The provided care will be documented in an electronic treatment progress form to be filled by the treating/ receiving dentists who will provide care to the children enrolled in the study.

The combination of groups along the two factors produces four experimental conditions shown in Table 2.

## Training and calibration

Training and calibration on ECC assessment using CAST index [19–21], and assignment into different care need categories will be conducted, and Kappa will be calculated. A Kappa score for intra examiner agreement above 0.75 will be considered acceptable [45].

## Study outcomes

### Primary outcome

The primary outcome is the percentage of teeth receiving indicated care per child. This will be calculated as (a) the number of teeth receiving topical fluoride application out of all teeth assigned in this category (CAST codes 3–5), (b) the number of teeth receiving restorative care out of all teeth assigned in this category (CAST code 5 depending on the clinical condition) and (c) the number of teeth receiving restorative care and/ or pulp therapy out of all teeth assigned in this category (CAST codes 6–7). Care receipt will be verified by checking the treatment form filled by the treating/ receiving dentist. If the form is incomplete, the treatment provided will be verified by parents’ reports and clinical examination when possible. The assessment of receipt of indicated care will be done after 6- and 12-months.

### Secondary outcomes

**Percentage of preventive visits completed per child** The number of preventive visits that are attended per child out of the three indicated visits (at baseline, 6- and 12-months) will be assessed.

**Rate of treatment completion** Treatment completion rate will be assessed by assessing the total procedures
received out of all procedures the child was indicated to receive. This will be assessed at 6- and 12-months.

**Oral health-related quality of life** Oral health-related quality of life will be assessed at baseline, and after 6- and 12-months using the Arabic Version of Early Childhood Oral Health Impact Scale (ECOHIS) [46, 47]. It was originally developed to assess the impact of oral health problems and related treatment on the quality of life of preschool children and their families [46]. The scale comprises 13 items in two main sections: the Child Impact Sect. (9 items) and the Family Impact Sect. (4 items). The Child Impact Section has four domains: child symptom (one item), child function (four items), child psychology (two items) and child self-image and social interaction (two items). The Family Impact Scale has two domains: Parental distress (two items) and Family function (two items). The response options are coded: 0=never; 1=hardly ever; 2=occasionally; 3=often; 4=very often. "I don't know" response was also proposed as an option. ECOHIS scores are calculated by summing the response codes for the child and family sections separately. The values range from 0 to 52 for the total scale (0–36 for the child section and 0–16 for the family section). Higher scores indicate greater impact of the state of oral health with worse quality of life.

**Acceptance of teledentistry by dentists** Perceptions towards teledentistry of participating dentists will be assessed using a semi structured interview and a questionnaire (Appendix 2) adapted from the unified theory of acceptance and use of technology (UTAUT) model [48, 49]. The model aims to clarify why individuals intend to use information technology based on four primary factors: performance expectancy, effort expectancy, social influence, and facilitating conditions. Tele-dentists will also be asked about their level of confidence in ECC tele-detection using a Visual Analogue Scale ranging from 0 (not confident at all) to 100 (extremely confident) [50].

**Procedure time** The time needed for intra-oral scanning using the two tele-detection methods will be recorded per patient, and the average time will be calculated and compared between the two methods. The time by the dentist assigning the CAST codes based on the tele-detection methods will also be calculated.

**Child's behavior and mood during the procedure** The child's behavior during dental photography will be assessed through direct observation of the patients using the following indicators: fear of the device, tendency to bite the device, difficulty in keeping the mouth open, opposition of the procedure, and cooperation [51]. These indicators represent potential barriers against successful completion

of the procedure. For the mood evaluation, the modified Positive and Negative Affect Schedule (PANAS) scale will be used [51, 52]. Four positive outcomes will be assessed: attention, enthusiasm, interest, pride, in addition to four negative outcomes: scare, nervousness, agitation, and hostility. All behavior and mood outcomes will be assessed on a 5-point Likert scale.

**Sample size estimation**

Previous research on the effectiveness of CCT on the use of oral healthcare services by <6 year old children reported an adjusted odds ratio (AOR) of 1.92 [53] with an effect size (f)=0.18 [54]. Other studies reported AOR=3.07, f=0.31 for CCT on non-dental visits [55]. Studies on UFR are less common, with reported mean (SD) number of healthcare visits by children younger than 5 years of age before and after UFR=13,203 (584.4) and 16,815 (1645.3), and calculated f=1.62 [56]. Using the lowest values (f=0.18) in the G* Power 3.1.9.7 [57] calculator for linear regression to detect main effects and interaction in a factorial design, we specified alpha error=5% and study power=80%. For the four conditions in Table 2, we used numerator df= (2 detection levels – 1) × (2 referral levels – 1)=1×1=1. A total sample size of 245 or 62 for each of the 4 experimental condition will be needed. This will be increased to 120 per condition, with a total of 480 children for all experimental conditions to make up for loss to follow up and allow estimation of effects on receiving different types of treatment.

**Randomization, allocation concealment and blinding**

Participants fitting the inclusion criteria will be randomly assigned in blocks of 12, as a multiple of the study groups, using a computer-generated list of random numbers to one of the four experimental conditions [58]. Identical sheets of paper with the group to which each child is allocated will be placed inside opaque envelopes carrying the respective names of the children. A trial-independent person will keep the envelopes and unfold them only at the time of intervention application [59]. Only the outcome assessor will be blinded since blinding of participants and operators will not be possible [60].

**Data management and statistical analysis**

Descriptive statistics will be calculated using means and standard deviation for quantitative variables, while frequencies and percentages will be used for qualitative variables. Intention to treat analysis will be used. The levels of the two intervention factors will be effect coded as -1 (for the smart phone group and the conventional referral group) and +1 (for the intra oral camera group and the UFR group) [61, 62]. Two-way analysis of variance will be used to assess the effect of the two factors as between group variables on the quantitative primary
outcome (percentage of teeth receiving indicated care) after 6 and 12 months. The interaction between detection methods and referral pathways will also be assessed. The effect of confounders will be controlled in a multivariable linear regression model. Confounders are child characteristics including age, sex, and cooperation, family characteristics including mother's education, family income and number of children in the family [63] as well as provider characteristics including age, sex and specialization. Regression coefficient and 95% confidence intervals will be calculated for main effects and interaction terms [41, 64]. Statistical analyses will be performed using SPSS for Windows version 26. The significance level will be set at $P<0.05$.

## Data monitoring

An interim analysis will be conducted at 6 months to evaluate the progress in outcomes after applying the detection methods and referral pathways. Due to the non-invasive nature of the interventions, no stopping rules will be planned beforehand to terminate the study. Every participant will be guaranteed the opportunity to withdraw from the study without any constraints if they deem the interventions to be unacceptable. Data will be internally monitored by the study team through random checks of 10% of entries monthly to ensure completeness and accuracy. No Data Monitoring Committee is available in the Faculty of Dentistry, Alexandria University. Therefore, no external data monitoring will be conducted.

## Harms

The potential risks to participants because of the study are related to data security and privacy, as well as the possibility that participants may not receive treatment for urgent conditions. To mitigate these risks, data will be safeguarded through password protection and restriction of access solely to the research team. Also, a robust follow-up procedure will be developed with an assigned person to confirm that participants receive the intended care in a timely manner.

## Ethical considerations

This research protocol was approved by the Research Ethics Committee of Alexandria University Faculty of Dentistry (#0723-07/2023) prior to any research-related activities. All research activities involving human subjects will abide by the Declaration of Helsinki and other ethical guidelines [65] adopted by the Research Ethics Committee of the Faculty of Dentistry, Alexandria University. The risks and benefits of the study will be explained to parents/guardians in a language that can be understood by them. They will be asked to sign an informed consent prior to treatment.

## Privacy and confidentiality

Each participant will be provided with a serial number that will only be accessible to the principal investigator. This number will be listed beside the participant's name and other identifiers in a master sheet with the PI. Only the serial number will be used for participant identification in the data files accessed by the other members of the study team and all other identifiers will be removed. No information about the identity of the participants will be shared under any circumstances.

## Trial status

The original version of the protocol was issued on the 23rd of August 2023. The recruitment was planned to start on the 1st of January 2024 and end by June 2024. Any changes or protocol amendments will be made to the study record available on ClinicalTrials.gov (ID: NCT06019884).

## Biological samples

No biological samples will be collected in this trial and therefore, no plans are made for their collection, evaluation, or storage.

## Ancillary and post-trial care

There are no expected adverse outcomes from the interventions. However, there is a possibility that participants may not promptly receive treatment for urgent conditions. The study team will follow-up all included participants to make sure they received the designated care. Additionally, the study team will make sure that children not meeting the inclusion criteria will be referred to pediatric dentistry specialists in the Faculty of Dentistry, Alexandria University or the MoH clinics to receive the required treatment.

## Dissemination policy

The results of the study will be disseminated through international peer-reviewed journals and conferences. There is no intention to use the services of professional writers. All authors of the final manuscript will fulfil the authorship criteria as recommended by the International Committee of Medical Journal Editors. The full protocol is also provided as a supplementary file and the final dataset will be available on reasonable request from the principal investigator.

## Discussion

ECC is a largely preventable condition, and its progression can be arrested or reversed if identified early [1]. The challenge, however, lies in its early detection, especially at the white spot lesion and early-stage levels [8]. This study recognizes the importance of early detection for timely intervention and aims to address the existing
gap by assessing the effectiveness of two tele-detection methods combined with two referral pathways with and without UFR.

The two intervention factors are particularly relevant to the study setting in Egypt. A recent report of the Egyptian Dental Syndicate showed that despite the large number of dentists registered in Egypt which reaches about 76,843, the number of pediatric dentists who are trained to provide advanced care to children is minimal, reaching about 762 or 1% of all registered dentists [66]. The use of teledentistry allows the early identification of ECC lesions by auxiliary healthcare personnel, or other healthcare personnel who provide services to children in the public healthcare facilities spread all over the country. It also enables general dental practitioners without pediatric dentistry training to seek consultations from specialists on referral needs thus enabling pediatric dentists to focus on treatment provision rather than ECC screening.

While evidence supports the accuracy of intraoral cameras with fluorescent light in caries detection [11, 12, 67–70], smartphones offer a promising alternative due to their accessibility, cost-efficiency, and integration possibilities [14, 71, 72]. Their use can extend the reach of oral healthcare by enabling remote assessment, particularly in underserved or remote communities thus reducing inequalities in access to care and avoiding creating inequalities due to digital technologies. Tele-dentistry remote diagnosis systems can help in the early detection of oral diseases, reducing referral time and improving access to dental care. Also, the dental experience of the screened children and their families who are exposed to the use of electronic equipment and who receive advice from dentists may increase patient awareness and motivation to maintain proper oral hygiene which protects against caries [9, 10, 18].

The second intervention factor includes UFR as a financial incentive for preventive care. Incentivizing families to prioritize dental health through UFR can lead to early detection of dental problems, timely interventions, and ultimately, improved oral health outcomes, particularly among vulnerable populations. This factor can play a vital role in promoting equitable access to healthcare services, encouraging preventive care, and ultimately contributing to better health outcomes for communities facing socioeconomic challenges.

Thus, the trial addresses a critical aspect of pediatric oral health, and its findings have the potential to inform clinical practice and policy setting for ECC management. This supports the planning of more effective preventive and treatment strategies for ECC. Successful tele-detection methods and referral pathways could be integrated into oral healthcare systems, leading to improved oral health outcomes for children. Additionally, the

study paves the way for further research on innovative approaches for early detection and management of ECC.

## Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12903-024-04706-8.

Supplementary Material 1

Supplementary Material 2

## Acknowledgements

This paper is based upon work supported by the Science, Technology & Innovation Funding Authority (STDF) under grant #47235.

## Author contributions

NMA and MET conceptualized the study, designed its methods, and drafted the manuscript. NMA will collect and analyze the data. NMA, MKE and MET will interpret the study results. MKE, NG, and MET are the project supervisors. All authors revised and reviewed the final approval of the manuscript.

## Funding

This paper is based upon work supported by the Science, Technology & Innovation Funding Authority (STDF), project # 47235.

## Data availability

No datasets were generated or analysed during the current study.

## Declarations

### Ethics approval and consent to participate

This research protocol was approved by the Research Ethics Committee of Alexandria University Faculty of Dentistry #0723-07/2023 prior to any research-related activities. Parents/legal guardians will be asked to sign an informed consent prior to treatment.

### Consent for publication

Not applicable.

### Competing interests

MET is a senior board member in BMC Oral Health. Other authors declare no competing interests.

Received: 22 November 2023 / Accepted: 5 August 2024

Published online: 11 August 2024

## References

1. Anil S, Anand PS. Early Childhood caries: prevalence, risk factors, and Prevention. Front Pediatr. 2017;5:157.

2. Peres MA, Macpherson LMD, Weyant RJ, Daly B, Venturelli R, Mathur MR, et al. Oral diseases: a global public health challenge. Lancet. 2019;394:249–60.

3. Righolt AJ, Jevdjevic M, Marcenes W, Listl S. Global-, regional-, and country-level economic impacts of dental diseases in 2015. J Dent Res. 2018;97:501–7.

4. El Tantawi M, Folayan MO, Mehaina M, Vukovic A, Castillo JL, Gaffar BO, et al. Prevalence and Data Availability of Early Childhood Caries in 193 United Nations Countries, 2007–2017. Am J Public Health. 2018;108:1066–72.

5. Institue for Health Metrics and Evaluation. Financing Oral Health. 2021. https://vizhub.healthdata.org/fgh/. Accessed 1 Oct 2022.

6. World Bank. Population, total - Middle East & North Africa. 2022. https://data.worldbank.org/indicator/SP.POP.TOTL?locations=ZQ&most价值 desc=true. Accessed 1 Oct 2022.

7. Ahmed SM, Soliman AMA, Elmagrabi NM, Sayed S. Oral health knowledge, attitude and practice among primary school children in rural areas of Assiut governorate. Egypt J Community Med. 2015;33:1–12.
8. Xiao J, Fiscella KA, Meyerowitz C, mDentistry. A powerful tool to improve oral health of a broad population in the digital era. J Am Dent Assoc. 2021;152:713-6.

9. Maqsood A, Sadiq MSK, Mirza D, Ahmed N, Lal A, Alam MK, et al. The Teledentistry, Impact, current trends, and application in Dentistry: A Global Study. Biomed Res Int. 2021;2021:5437237.

10. Hung M, Lipsky MS, Phuatrakoon TN, Nguyen M, Licari FW, Unni EJ. Tele-dentistry implementation during the COVID-19 pandemic: scoping review. Interact J Med Res. 2022;11:e39955.

11. Inquimbert C, Hirata-Tsuchiya S, Yoshii S, Molinari N, Nogue E, Roy C, et al. Concordance study between regular face-to-face dental diagnosis and dental telediagnosis using fluorescence. J Telemed Telecare. 2021;27:509-17.

12. Inquimbert C, Balacianu I, Huyge N, Pasdeloup J, Tramini P, Meroueh F, et al. Applications of teledentistry in a French inmate population: a one-year observational study. PLoS ONE. 2021;16:e0247778.

13. AlShaya MS, Assery MK, Pani SC. Reliability of mobile phone teledentistry in dental diagnosis and treatment planning in mixed dentition. J Telemed Telecare. 2020;26:45-52.

14. AlShaya M, Farsi D, Farsi N, Farsi N. The accuracy of teledentistry in caries detection in children - a diagnostic study. Digit Heal. 2022;8:20552076221109076.

15. Zotti F, Rosolin L, Simoncelli F, Pappalardo D, Cominiolli A, Zerman N. Telediagnosis of dental caries: possible or impossible? A pilot cross-sectional study. Clin Exp Dent Res. 2022;8:1614-22.

16. Ashtiani GH, Sabbagh S, Moradi S, Azimi S, Ravaghi V. Diagnostic accuracy of tele-dentistry in screening children for dental caries by community health workers in a lower-middle-income country. Int J Paediatr Dent. 2024. https://doi.org/10.1111/ipd.13157.

17. The World Bank. The World by Income and Region. 2023. https://datatopics.worldbank.org/world-development-indicators/the-world-by-income-and-region.html. Accessed 20 Sep 2023.

18. Sharma H, Suprabha BS, Rao A. Teledentistry and its applications in paediatric dentistry: a literature review. Pediatr Dent J. 2021;31:203-15.

19. Frencken JE, de Amorim RG, Faber J, Leal SC. The Caries Assessment Spectrum and Treatment (CAST) index: rational and development. Int Dent J. 2011;61:117-23.

20. Leal SC, Ribeiro APD, Frencken JE. Caries Assessment Spectrum and Treatment (CAST): a Novel Epidemiological Instrument. Caries Res. 2017;51:500-6.

21. de Souza AL, Bronkhorst EM, Creugers NHJ, Leal SC, Frencken JE. The caries assessment spectrum and treatment (CAST) instrument: its reproducibility in clinical studies. Int Dent J. 2014;64:187-94.

22. Villena PS, Pesaressi E, Frencken JE. Reducing carious lesions during the first 4 years of life: an interprofessional approach. J Am Dent Assoc. 2019;150:1004-14.

23. Fernandez MDS, Pauli LA, da Costa VPP, Azevedo MS, Goettems ML. Dental caries severity and oral health-related quality-of-life in Brazilian preschool children. Eur J Oral Sci. 2022;130:e12836.

24. Reddy ER, Rani ST, Manjula M, Kumar LV, Mohan TA, Radhika E. Assessment of caries status among schoolchildren according to decayed-missing-filled teeth/decayed-extract-filled teeth index, International Caries Detection and Assessment System, and Caries Assessment Spectrum and Treatment criteria. Indian J Dent Res. 2017;28:487-92.

25. CariesCare International Group. CariesCare International. 2023. https://caries-careinternational.com/%0A. Accessed 10 Jun 2023.

26. Martignon S, Pitts NB, Goffin G, Mazevet M, Douglas GVA, Newton JT, et al. CariesCare practice guide: consensus on evidence into practice. Br Dent J. 2019;227:353-62.

27. American Academy of Pediatric Dentistry. Caries-risk Assessment and Management for infants, children, and adolescents. Pediatr Dent. 2017;39:197-204.

28. Goff SL, Gahlon G, Geissler KH, Dick AW, Kranz AM. Variation in current guidelines for Fluoride Varnish Application for Young Children in Medical Settings in the United States. Front Public Health. 2022;10:785296.

29. Soliman NIE. Oral health beliefs, knowledge, and behavioral attitudes of Egyptian mothers resident in Giza city towards early childhood caries. Egypt Dent J. 2019;65:917-26.

30. Abbass MMS, Mahmoud SA, El Moshy S, Rady D, AbuBakr N, Radwan IA, et al. The prevalence of dental caries among Egyptian children and adolescents and its association with age, socioeconomic status, dietary habits and other risk factors. A cross-sectional study. F1000Research. 2019;8:8.

31. El Tantawi M, Aly NM, Folayan MO. Unemployment and expenditure on health and education as mediators of the association between toothbrushing and global income inequalities. BMC Oral Health. 2022;22:539.

32. El Tantawi M, Hamza MA, Sabry MM. Dentists' perception of primary health care services in family health and mother and child health clinics in Alexandria, Egypt. East Mediterr Health J. 2017;23:73-9.

33. Lagarde M, Haines A, Palmer N. The impact of conditional cash transfers on health outcomes and use of health services in low and middle income countries. Cochrane Database Syst Rev. 2009;2009:CD008137.

34. Fernald LCH, Gertler PJ, Neufeld LM. Role of cash in conditional cash transfer programmes for child health, growth, and development: an analysis of Mexico's oportunidades. Lancet (London England). 2008;371:828-37.

35. Bassani DG, Arora P, Wazny K, Gaffey MF, Lenters L, Bhutta ZA. Financial incentives and coverage of child health interventions: a systematic review and meta-analysis. BMC Public Health. 2013;13(3 Suppl 3):S30.

36. Hernández-Vásquez A, Azañedo D, Vargas-Fernández R, Basualdo-Meléndez GW, Barón-Lozada FA, Comandé D. Impact of cash transfers on the Use of Oral Health Services and oral Health outcomes: a systematic review. J Int Soc Prev Community Dent. 2022;12:323-39.

37. Colvara BC, Singh A, Gupta A, Celeste RK, Hilgert JB. Association between cash transfer programs and oral health-A scoping review. J Public Health Dent. 2023;83:69-77.

38. Michie S, van Stralen MM, West R. The behaviour change wheel: a new method for characterising and designing behaviour change interventions. Implement Sci. 2011;6:42.

39. Chan A-W, Tetzlaff JM, Altman DG, Laupacis A, Gøtzsche PC, Krleža-Jerić K, et al. SPIRIT 2013 statement: defining standard protocol items for clinical trials. Ann Intern Med. 2013;158:200-7.

40. Montgomery A, Kahan B, Elbourne D, Beller E, Juszczak E, Little P et al. Reporting of randomised factorial trials: development of extensions to the CONSORT 2010 and SPIRIT 2013 guidance statements. 2021. https://www.equator-network.org/wp-content/uploads/2021/10/RAFT-Study_Proto-col_Final-version-1.1_27-Sept-2021-clean.pdf. Accessed 18 Jun 2023.

41. Montgomery AA, Peters TJ, Little P. Design, analysis and presentation of factorial randomised controlled trials. BMC Med Res Methodol. 2003;3:26.

42. Acteon Group, Full C. HD camera. 2023. acteongroup.com/en/products/imaging/intraoral-cameras/c50-full-hd-camera/%0A. Accessed 12 Jun 2023.

43. Samsung. Galaxy A24. 2023. samsung.com/ph/smartphones/galaxy-a/galaxy-a24-green-128gb-sm-a245flgwph/. Accessed 30 Jun 2024.

44. American Academy of Pediatric Dentistry. Oral Health Policies & Recommendations (The Reference Manual of Pediatric Dentistry). 2023. https://www.aapd.org/research/oral-health-policies--recommendations/. Accessed 10 Oct 2023.

45. McHugh ML. Interrater reliability: the kappa statistic. Biochem Med. 2012;22:276-82.

46. Pahel BT, Rozier RG, Slade GD. Parental perceptions of children's oral health: the early childhood oral health impact scale (ECOHIS). Health Qual Life Outcomes. 2007;5:6.

47. Farsi NJ, El-Housseiny AA, Farsi DJ, Farsi NM. Validation of the Arabic Version of the early childhood oral health impact scale (ECOHIS). BMC Oral Health. 2017;17:60.

48. Venkatesh V, Morris MG, Davis GB, Davis FD. User acceptance of information technology: toward a unified view. MIS Q. 2003;425-78.

49. Alabdullah JH, Van Lunen BL, Claiborne DM, Daniel SJ, Yen C-J, Gustin TS. Application of the unified theory of acceptance and use of technology model to predict dental students' behavioral intention to use teledentistry. J Dent Educ. 2020;84:1262-9.

50. Menhadji P, Patel R, Asimakopoulou K, Quinn B, Khoshkhounejad G, Pasha P, et al. Patients' and dentists' perceptions of tele-dentistry at the time of COVID-19. A questionnaire-based study. J Dent. 2021;113:103782.

51. Petcu R, Kimble C, Ologeanu-Taddei R, Bourdon I, Giraudeau N. Assessing patient's perception of oral teleconsultation. Int J Technol Assess Health Care. 2017;33:147-54.

52. Watson D, Clark LA. Measurement and mismeasurement of mood: recurrent and emergent issues. J Pers Assess. 1997;68:267-96.

53. Calvasina P, O'Campo P, Pontes MM, Oliveira JB, Vieira-Meyer APGF. The association of the Bolsa Familia Program with children's oral health in Brazil. BMC Public Health. 2018;18:1186.

54. SPSS Tutorials. Effect Size - A Quick Guide. 2022. https://www.spss-tutorials.com/effect-size/#linear-regression. Accessed 1 Oct 2022.
55. Onwuchekwa C, Verdonck K, Marchal B. Systematic review on the Impact of Conditional Cash Transfers on Child Health Service Utilisation and Child Health in Sub-saharan Africa. Front Public Health. 2021;9:643621.

56. Burnham GM, Pariyo G, Galiwango E, Wabwire-Mangen F. Discontinuation of cost sharing in Uganda. Bull World Health Organ. 2004;82:187-95.

57. Faul F, Erdfelder E, Lang A-G, Buchner A. G* power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007;39:175-91.

58. SealedEnvelope. Create a blocked randomisation list. 2022. https://www.sealedenvelope.com/simple-randomiser/v1/lists. Accessed 13 Jun 2023.

59. Altman DG, Schulz KF. Statistics notes: concealing treatment allocation in randomised trials. BMJ. 2001;323:446-7.

60. Karanikolas PJ, Farrokhyar F, Bhandari M. Blinding: who, what, when, why. how? Can J Surg. 2010;53:345-8.

61. Kugler KC, Dziak JJ, Trail J. In: Collins LM, Kugler KC, editors. Coding and interpretation of effects in analysis of data from a factorial experiment BT - optimization of behavioral, Biobehavioral, and Biomedical interventions: Advanced Topics. Cham: Springer International Publishing; 2018. pp. 175-205.

62. Office for Health Improvement and Disparities. Factorial randomised controlled trial: comparative studies. How to use a factorial randomised controlled trial to evaluate your digital health product. 2020. https://www.gov.uk/guidance/factorial-randomised-controlled-trial-comparative-studies. Accessed 17 Jun 2023.

63. World Health Organization. Oral health surveys: basic methods. 5th edition. World Health Organization; 2013.

64. Piantadosi S. Factorial Designs in Clinical Trials. In: Wiley Encyclopedia of Clinical Trials. 2008. p. 1.

65. Goodyear MDE, Krieza-Jeric K, Lemmens T. The declaration of Helsinki. BMJ. 2007;335:624-5.

66. Egyptian Dental Syndicate. A study of dentists' numbers based on the General Syndicate records. 2021. https://eds-eg.org/dentistry_statistics. Accessed 10 Sep 2023.

67. Inquimbert C, Malthierry E, Arzens G, Camman P, Charvier M, Cuisinier F, et al. In: Giraudeau N, editor. Teledentistry in France: Example of the e-DENT Project BT - e-Health Care in Dentistry and oral medicine: a clinician's guide. Cham: Springer International Publishing; 2018. pp. 143-54.

68. Giraudeau N, Camman P, Pourreyron L, Inquimbert C, Lefebvre P. The contribution of teledentistry in detecting tooth erosion in patients with eating disorders. Digit Heal. 2021;7:20552076211019250.

69. Terrer E, Slimani A, Giraudeau N, Levallois B, Tramini P, Bonte E, et al. Performance of fluorescence-based systems in Early Caries detection: a Public Health Issue. J Contemp Dent Pract. 2019;20:1126-31.

70. Vigarios E, Warnakulasuriya S, Piau A, Giraudeau N, Maret D. Early detection of oral malignancies may involve the development of tele-expertise in dentistry. Oral Oncol. 2022;130:105904.

71. Kohara EK, Abdala CG, Novaes TF, Braga MM, Haddad AE, Mendes FM. Is it feasible to use smartphone images to perform telediagnosis of different stages of occlusal caries lesions? PLoS ONE. 2018;13:e0202116.

72. Estai M, Kanagasingam Y, Xiao D, Vignarajan J, Bunt S, Kruger E, et al. End-user acceptance of a cloud-based teledentistry system and android phone app for remote screening for oral diseases. J Telemed Telecare. 2017;23:44-52.

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