Determination of caries risk of Finnish preschool-aged children and targeting prevention for at-risk individuals: a register-based pilot study

Abstract

Purpose

Preventive dental care is an essential part of promoting children’s oral health. The purpose of this retrospective register-based observational study was to find out whether caries risk and risk factors were individually assessed in children under school age, and whether the observed risk factors affected the recall intervals (RCs) and the implementation of preventive measures for at-risk patients.

Methods

The data consisted of patient records of Finnish children under school age (0–6 years) (n = 206) in oral health care and public maternity and child health clinics between 2014 and 2020. The children were born in 2014, 2016 and 2018 and lived in the City of Oulu, Finland. Data on different caries risk factors, preventive factors and measures, and RC intervals were registered for three different age groups (1–2-, 3–4- and 5–6-year-olds). Chi-squared and Fisher´s exact tests were used to evaluate registrations across three age groups.

Results

The frequency of registering of different caries risk factors varied by age group (3.7–98.3%) and the assessing of individual caries risk in patient registers was inadequate (0–3.2%). RC intervals were not systematically determined based on individual risk; however, when recorded risk factors were considered, an increase in the number of factors was associated with a shortening of the RC intervals (p < 0.001). Prevention was not targeted toward caries-risk patients. Children in the age groups of 1–2-year-olds and 3–4-year-olds with ≥ 3 recorded risk indicators had a statistically significantly higher presence of caries lesions than others.

Conclusion

Registering caries risk factors, identifying at-risk individuals and targeting prevention accordingly form the basis of good dental care for children. All oral health professionals should be better aware of and follow national recommendations and guidelines.

Introduction

The prevention of early childhood caries (ECC) is the subject of international interest, and the topic has been widely studied from different perspectives. According to WHO statistics (Global Burden of Disease Collaborative Network, [1]), more than a third of Finnish, Swedish and Norwegian 1–9-year-old children still have untreated caries in their deciduous teeth, although in a long-term comparison the prevalence is generally decreasing [2] in Europe. However, it should be kept in mind that caries burden has been found to be even higher in deciduous teeth than in permanent dentition [3]. Also, in Germany, a 15-year follow-up showed that the decline in caries was slower in deciduous dentition than in permanent dentition [4]. For favorable development to continue, it is important to continue to target preventive dental care measures already in early childhood for those who need it.

Dental caries is a preventable disease, and properly timed prophylaxis has been shown to be efficacious [5] as well as cost-effective [6]. Investing in the promotion of children’s oral health also leads to improved health later in life. Dental caries in deciduous teeth has been identified as a significant risk indicator for decay in permanent teeth [7–12] as well as decreased overall quality of life among children and their families [13–16].

The emergence and development of caries lesions is due to the influence of various factors [17–19]. A single risk factor does not necessarily mean the development of caries, but the simultaneous presence of multiple risk factors predisposes individuals to oral health challenges. Determining the risk of dental caries and making individual caries management and treatment plans are an essential part of the dental care of pediatric patients, and it should be done routinely at every oral health examination [20].

The Finnish Good Clinical Practice Consensus Recommendation (Oral examination and treatment intervals) [21] emphasizes individual risk assessment. The Finnish Current Care Guideline for Caries (control) [22] recommends including medical, social, and behavioral factors alongside clinical findings when assessing caries risk. It also provides guidance for determining the patient-specific recall (RC) interval. However, in light of existing research, it is still somewhat unclear how the length of the RC intervals should be determined due to the lack of evidence [23]. On the other hand, the interval should be sufficient and cost-effective not only at the individual level but also from the perspective of society. According to Finnish legislation, every child below school age must be guaranteed at least three check-ups with an oral health care professional [24, 25].

The aim of this study was to investigate whether individual caries risk, including related factors, is determined and registered for pediatric patients. In addition, our interest was whether the recorded risk factors associated with caries findings and affected the determination of recall intervals (RCs) and the preventive treatment of children, especially those at risk.

Materials and methods

Data collection

This retrospective register-based observational study using age-specific examination records was designed using the STROBE Checklist [26]. The register data of the study were collected from the electronic patient records of the City of Oulu for the period 2014–2020. The data were manually extracted from electronic patient records by an experienced pediatric dentist (one of the authors). Systematic random sampling was performed by using a number generator (Calculator.net). We employed a number generator to identify the first participant (separately from those born in 2014, 2016 and 2018) from a list ordered by date of birth. Subsequently, every 42nd child on the list was selected until the sample size specified by the power calculation was achieved. No child was excluded from study due to problems in general health or physical or mental disabilities. Children who had moved to or from the study location during the study period were excluded from the study. In total, this register-based study included the data of 206 children, who were 1–2-, 3–4- or 5–6-year-olds at baseline. The data consisted of multiple age-specific entries from dental records of children born in 2014, 2016 and 2018 and lived in the municipality for the entire study period (n = 206). The total number of oral health examinations was 345 (Fig. 1). Additionally, data were collected from the maternity and child health clinics.

Fig. 1.

Flow chart of the study design

The child’s year of birth was registered as background information. Dental caries was recorded as initial (non-cavitated) and dentin (cavitated) lesions as suggested for early childhood caries ECC [27]. All examinations were performed in fully equipped dental offices. The diagnosis of caries was based on clinical examination (visual, tactile and possibility to use fibre-optic transillumination). Alloral health care professionals used the same electronic patient record system and made the entries on the basis of an independent assessment in the structured status form, in which the clinical findings were recorded for each tooth surface. In addition, it was possible to add free text about self-care and dietary habits. Recorded risk factors for caries were pufa-index (0 / ≥ 1), extracted teeth due to dental caries (yes / no), visible plaque (yes / no / missing information), snacking habits (yes / no / missing information), diet containing added sugar (yes / no / missing information), and use of sugar-sweetened beverages (SSBs) (yes / no / missing information). Additionally, family-related and dental attendance-related risk indicators were recorded every time when mentioned such as challenges in life (parental exhaustion, sleeping or behavioral problems of a child, death or grief in the family, need for support from social services or child living in out-of-home care, guardian's unemployment or self-reported problems with mental health, divorce of parents or problems in the parents' relationship) (yes / no), dental anesthesia treatment (DGA) (yes / no), missing appointments at public child health clinic (yes / no), dental health care clinic (absenteeism) (yes / no) and referrals to the child protection services (CPS) (yes / no). Based on the entries in patient records, the caries risk factors were registered by an oral health professional (dentist / oral hygienist / dental nurse) or maternity and child health clinic nurse. In the analyses, caries risk factors were dichotomized based on previous findings from the same data [28] 0–2 or ≥ 3.

With regard to preventive self-care according to Finnish Current Care Guidelines for Caries (control) [22], notes were recorded in the patient records on tooth brushing (tooth brushing twice daily / once a day / less than once a day / never / missing information), supervised tooth brushing (yes / no / missing information), the use of fluoride toothpaste (yes / no / missing information), the use of additional fluoride and the use of xylitol chewing gum or lozenges (yes / no / missing information). Information on preventive measures performed by an oral health professional included application of fluoride varnish (yes / no), placement of sealants (yes / no), provision of oral hygiene counselling (yes / no), and provision of dietary counselling (yes / no).

Data and statistical analysis

Power calculation was performed to determine the sample sizes, assuming that the difference in caries risk factors (3 or more) between shortened recall interval group is 18% (23% − 5%). With a significance level of alpha = 0.05 and a power (1 - Beta) of 0.8, the required sample size was determined to be at least 52 per age group (1–2, 3–4, and 5–6-years).

Data was presented in frequencies and proportions. Associations between the caries risk factors and other variables were analyzed using chi-square or Fisher’s exact tests. A statistically significant difference between the groups was defined as p < 0.05. The statistical analyses were performed using IBM SPSS Statistics for Windows, Version 29.0 (Armonk, NY: IBM Corp).

Ethical considerations

Permission was obtained from the City of Oulu, the data controller of the medical registers (OUKA/12798/07.01.04.02/2021). Based on Finnish legislation [29], no statement from the regional medical research ethics committee of the Wellbeing Services County of North Ostrobothnia was necessary for this study. The anonymity of the research subjects was protected at all stages of the study by utilizing ID numbering, the key to which was held only by the first author.

Results

The risk of ECC was not assessed and/or registered by oral health professionals at all for children aged 1–2 and 3–4 years, and a small proportion for children aged 5–6 years (3.2%) (Table 1). Based on factors found by the author from patient records, 4.3% of the children aged 1–2 years, 7.7% of those aged 3–4 years, and 11.1% of those aged 5–6 years had ≥ 3 caries risk factors. Having at least three risk factors was associated with initial or dentinal caries lesions (p-values 0.005, 0.002, 0.065 according to the age group). An increase in the number of risk factors (as assessed by an oral health care professional or researcher) was associated with a shortening of the RC interval (p < 0.001) (Fig. 2).

Table 1.

Recording of caries risk factors, caries risk, and RC intervals in patient records at different age levels

	1–2-years (n = 164)	3–4-years (n = 118)	5–6-years (n = 63)
	n (%)	n (%)	n (%)
At least one risk indicator for caries in patient records	67 (40.9)	62 (52.5)	37 (58.7)
Shortened RCs	5 (7.5)	12 (19.4) *	8 (21.6)
Caries lesions registered (initial/dentinal)
0–2 risk factors	4 (2.4)	5 (4.2)	13 (20.6)
≥ 3 risk factors	3 (1.8) *	4 (3.4) *	6 (9.5)
Caries risk registered	0	0	2 (3.2)
RC interval shortened if
Initial/dentinal caries lesions	3 (1.8)	9 (7.6)	6 (9.5)
pufa index > 0	2 (1.2)	1 (0.8)	3 (4.8)
Extracted teeth due to caries	1 (0.6)	2 (1.7)	3 (4.8)
Challenges in family life	0	4 (3.4)	2 (3.2)
Absenteeism	0	1 (0.8)	1 (1.6)
Referral to CPS	0	1 (0.8)	0
DGA	1 (0.6)	2 (1.8)	1 (1.6)

Fisher´s Exact Test * p < 0.05

Fig. 2.

Effect of the number of risk factors for caries on the shortening of the RC intervals in all age groups

The proportions of different oral health care professionals involved in oral health screenings of pediatric patients varied: for 1–2 and 3–4-year-olds, the majority of oral health screenings were performed by dental nurses (72.6–77.3%), while for 5–6-year-olds, the role of oral hygienists was prominent (71.4%). For 5–6-year-olds, dentists assessed the need for shortening the RC interval more often than oral hygienists and dental nurses (p = 0.003). At the age of 3–4 years, the oral hygienist was more likely to shorten the child’s RC interval compared to the dental nurse (p = 0.045).

The registering of the child’s dietary factors varied according to the age group. The highest amount of missing data on diet was found among 1–2-year-olds (80–90% according to the variables) (Table 2). In the age group of 3–4-year-olds, the corresponding figures were 24–78%. In the oldest age group, less information was missing from patient records compared to younger age groups (19–24%).

Table 2.

Oral health care records related to child´s dietary habits

	1–2-years (n = 164)	3–4-years (n = 118)	5–6-years (n = 63)
	n (%)	n (%)	n (%)
Diet containing added sugar
Yes	33 (20.1)	27 (22.9)	14 (22.2)
No	51 (31.1)	67 (56.8)	30 (47.6)
Missing information	80 (48.8)	24 (20.3)	19 (30.2)
Snacking habits
Yes	10 (6.1)	8 (6.8)	14 (22.2)
No	64 (39.0)	32 (27.1)	30 (47.6)
Missing information	90 (54.9)	78 (66.1)	19 (30.2)
Use of sugar-sweetened beverages (SSBs)
More than once a week	9 (5.5)	22 (18.7)	4 (6.4)
Once a week	1 (0.6)	4 (3.4)	4 (6.4)
Seldom	13 (7.9)	28 (23.7)	18 (28.6)
No	58 (35.4)	31 (26.2)	13 (20.6)
Missing information	83 (50.6)	33 (28.0)	24 (38.0)

Also, entries related to self-care habits were incomplete (Table 3). Tooth brushing was registered comprehensively in patient records (94.5–98.3%), but more detailed information on parent-supervised brushing was documented less frequently. The use of fluoride toothpaste was mentioned in patient records for 47.6–78.0% of children, depending on age group. The use of xylitol products was registered for most children (78.0–85.6%). Visible plaque (yes / no) was registered for 8.5% of children aged 1–2 years, 39.8% of those aged 3–4 years, and 41.3% of those aged 5–6 years (Table 3). Children whose families had challenging situations in life had poorer toothbrushing habits in all age groups, although this finding was not statistically significant. In addition, these families had more snacking habits at ages 1–2 years (p = 0.030).

Table 3.

Registered oral health care related to self-care habits

	1–2-years (n = 164)	3–4-years (n = 118)	5–6-years (n = 63)
	n (%)	n (%)	n (%)
Tooth brushing
Twice daily	97 (59.1)	80 (67.8)	42 (66.6)
Once a day	47 (28.7)	29 (24.6)	15 (23.8)
Less than once a day	2 (1.2)	1 (0.8)	2 (3.2)
Never	9 (5.5)	6 (5.1)	2 (3.2)
Missing information	9 (5.5)	2 (1.7)	2 (3.2)
Tooth brushing supervised by a parent
Yes	6 (3.7)	21 (17.8)	15 (23.8)
No	0	3 (2.5)	2 (3.2)
Missing information	158 (96.3)	94 (79.7)	46 (73.0)
Use of fluoride toothpaste
Yes	113 (68.9)	79 (66.8)	30 (47.6)
No	37 (22.6)	1 (0.8)	0
Missing information	14 (8.5)	38 (32.2)	33 (52.4)
Use of xylitol products
Yes	91 (55.5)	95 (80.5)	46 (73.0)
No	37 (22.5)	6 (5.1)	4 (6.3)
Missing information	36 (22.0)	17 (14.4)	13 (20.7)

Preventive care visits and measures were infrequent (Table 4). In total, preventive measures were targeted at 32 children in the entire study group, of whom fewer than half (37.5%) had caries findings (initial or dentinal caries) or ≥ 3 caries risk factors. Of all the study subjects, supplemental fluoride was recommended for a total of four children. Dietary counselling was documented as being provided to four children and brushing guidance to 13 children. Fluoride varnishes were applied to a total of 34 children. In addition to the actual public dental care, self-care guidance was also offered by a public health nurse at the maternity and child health clinic, and it was most often given to the youngest children: 58.7% in the 1–2-year-old age group, 42.3% in 3–4-year-olds and 33.3% in 5–6-year-olds. There were no statistically significant differences between dentists, oral hygienists, and dental nurses in the implementation of prevention.

Table 4.

Targeting preventive caries measures at different age levels

	1–2-years (n = 164)	3–4-years (n = 118)	5–6-years (n = 63)
	n (%)	n (%)	n (%)
Fluoride varnish
0–2 risk factors	2 (1.2)	11 (9.3)	13 (20.6)
≥ 3 risk factors	1 (0.6)	3 (2.5)	4 (6.3)
Sealant
0–2 risk factors	0	1 (0.8)	0
≥ 3 risk factors	0	0	0
Oral hygiene counselling
0–2 risk factors	0	7 (5.9)	3 (4.8)
≥ 3 risk factors	0	3 (2.5)	1 (1.6)
Dietary counselling
0–2 risk factors	0	1 (0.8)	2 (3.2)
≥ 3 risk factors	0	0	1 (1.6)

Some children received more than one preventive measure at a certain age level. At 1–2 years, three children received preventive measures, at 3–4 years, 16 children, and at 5–6 years, 18 children

Discussion

The registering of risk factors in patient documents and the assessment of patient-specific risk or caries management plans were found to be insufficient. Based on our findings, the proper implementation of Finnish treatment recommendations in the oral health care of preschool-aged children may be questioned. The assessment and registering of risk factors in accordance with the Current Care Guidelines for Caries (control) (first published in 2009 and last update 2023) was deficient for most children. In particular, the accumulation of risk factors should be taken into account by an oral health care professional, as this was associated with a higher presence of caries. Based on the risk factors extracted from the patient records, 7.8% of all children had three or more caries risk factors, which is probably a lower figure than reality due to deficiencies in the registering of risk factors. Furthermore, registering varied between age groups, e.g. diet-related factors were missing in half of the 1–2-year-olds even though this information should be a part of overall assessment.

According to the Finnish Good Clinical Practice Recommendation [21] and the Current Care Guideline for Caries (control) [22], the determination of the RCs should be clearly based on a patient-specific risk assessment, which was not the case in this data. Identifying at-risk patients makes it possible to direct resources to those groups that most need and benefit from treatment [6, 30]. It should also be noted that during childhood, changing circumstances in a child’s life can rapidly affect risk, therefore risk assessment should be repeated regularly, and the situation should be reassessed periodically, even a two-year RC interval may be too long for high-risk individuals [31]. Previous studies have found an association between a family’s diverse life challenges and the utilization of dental care services that can have an impact on a child’s oral health [28, 32, 33] and emphasized the importance of assessing overall caries risk [31, 34, 35].

Based on previous systematic reviews, evidence related to the determination of the recall intervals of pediatric patients is vague, mainly due to the lack of research [23, 36]. However, it has been found that children with a longer examination interval have a higher risk of developing new cavitated caries lesions [37], and regular oral health examinations based on a patient-specific risk assessment have been shown to reduce the development of dental caries [5]. Additionally, it has been stated that RC intervals should be set according to risk [31]. An important result here was that oral health care professionals did not assess the appropriate patient-specific RC intervals based on the risk of caries, and almost all children were automatically offered statutory oral health screenings by age group (recall interval 24 months). If the RC interval was shortened, the reason for it was not systematically registered.

Prevention was not fully targeted at high-risk individuals and preventive procedures were, in general, performed quite infrequently. Only a third of the high-risk patients received preventive care. A similar finding was also observed in an earlier Finnish study among adults, as there were only minor differences between the preventive measures targeted at heavy users and those targeted at low users in oral health care [38]. Based on the results, it seems that the number of preventive measures increases in older children, which may be because at this stage, the signs of ECC also begin to show clinically. A systematic review [39] identified factors that challenge the implementation of caries prevention and found three different factors behind the challenge: clinician-related factors (e.g. knowledge, professional role and identity), patient-related factors (e.g. skills, resources) and organizational-related factors (environmental context and resources). Thus, there is a wide range of factors behind the preventive approach, not all of which were considered in this study.

All oral health care professionals should be aware of the importance of accurate patient records required by the law. They should periodically receive training on this, and organizations should commit to standardized registering practices. Patient records are important from the perspective of the legal protection of both the professional and the patient, the quality of care, and the evaluation and monitoring of the progress of the treatment. The electronic patient record systems in use should support the work of professionals in determining caries risk factors and risk assessment. In Finland, all health care visits are registered in electronic patient records, and they are assumed to be highly reliable [40] and the clinical findings detected here can be considered reliable. In Sweden the Swedish Quality Registry for Caries and Periodontal Disease (SKaPa) collects patient data and enables reliable and accurate register-based research on dental caries [41]. Currently, Finland does not have a national register that would reliably compile patient data like the SKaPa register in Sweden. However, quality register work focusing on oral diseases has recently begun in Finland.

In this study, it was also possible to assess the role of different oral health care professionals based on patient record entries. In Finland, oral health screenings of children under school age are most often carried out by dental nurses and oral hygienists [42], who are responsible for examining oral health and identifying any abnormal findings; they then refer the child to a dentist for further evaluation if necessary. However, the study of Pelkonen et al., [43], found that collaboration between oral health care professionals was scarce and only a small number of children were referred for a dentist’s assessment. Here, we found that dental nurses’ determination of the RCs was rarely based on an individual assessment, whereas oral hygienists performed the assessment of the RCs more often. Previously, a Danish prevention program (NexØ) based on a systematic guideline was implemented with good results. The dentist-dental nurse pair played a major role in the model, and it highlighted the importance of plaque control, self-care guidance, professional cleaning, and minimally invasive procedures [44].

The data in this study was collected from patient records made for clinical purposes, which is why, from a scientific point of view, some of the data was incomplete regarding certain variables. Data on caries lesions can be assumed as valid and reliable as recorded based on ECC guidelines [27], the same is true for preventive measures. The large proportion of missing data for some variables concerning risk and preventive factors can be considered as a limitation of the study. The lack of data and the relatively small number of subjects limited the possibility of using deeper statistical analyses. On the other hand, one purpose of this pilot study was to assess the quality of patient records, and the missing information was an important finding. However, documentation bias should be taken into account as children with more detailed patient records may appear to have more risk factors simply because information was recorded more meticulously. Preventive measures seemed to be infrequently targeted at high-risk patients reflecting either clinical practices or incomplete recordings of risk factors in the patient records. The data were manually extracted from patient records by one of the authors, which allowed for more extensive collection and analysis of variables compared to automated sampling. Although this pilot study population was limited and statistical analyses were based on a small sample size, it can still be considered representative of children living in the Ostrobothnia area in Northern Finland.

Conclusion

To conclude, it is important to ensure the competence of all professionals in assessing ECC risk, identifying at-risk patients, and in determining individual check-up and treatment intervals, for which there are tools available nationally and internationally. Preventive care should be targeted at an appropriately early stage, especially for pediatric patients at high risk of caries. All professionals should be aware of and follow national recommendations and guidelines.

Abbreviations

CPS

Child protection services

ECC

Early childhood caries

DGA

Dental general anesthesia

RC interval

Recall interval

SSBs

Sugar-sweetened beverages

WHO

World Health Organization

Authors’ contributions

study conception and design: A-M.P., H.V., V.A., M-L.L, P.R.; data collection: A-M.P.; analysis and interpretation of results: A-M.P., H.V., M-L.L., V.A. Author; draft manuscript preparation: A-M.P., M-L.L., V.A., P.R. All authors reviewed the results and approved the final version of the manuscript.

Funding

Open Access funding provided by University of Oulu (including Oulu University Hospital). This work was supported by the Alma and K.A. Snellman Foundation, Oulu, Finland under Grant 20250021. The funder had no role in the design of the study; collection, analysis, and interpretation of data; or in writing the manuscript.

Data availability

The data that support the findings of this study are not openly available due to reasons of sensitivity and are available from the corresponding author upon reasonable request. The data are located in a controlled-access data storage facility at the University of Oulu.

Declarations

Ethics approval and consent to participate

According to Finnish legislation (Data Protection Act 1050/2018) and the European Union’s General Data Protection Regulation (Article 9), a statement from the Regional Medical Research Ethics Committee of the Wellbeing Services County of North Ostrobothnia was not required.

Consent for publication

Separate consents to participate and publish the study results were not required in this register-based study (Data Protection Act 1050/2018 and the European Union’s General Data Protection Regulation, Article 9).

Competing interests

The authors declare no competing interests.