Contesting the conventional wisdom of periodontal risk assessment

Over the years, several reviews of periodontal risk assessment tools have been published. However, major misunderstandings still prevail in repeated attempts to use these tools for prognostic risk prediction. Here we review the principles of risk prediction and discuss the value and the challenges of using prediction models in periodontology. Most periodontal risk prediction models have not been properly developed according to guidance given for the risk prediction model development. This shortcoming has led to several problems, including the creation of arbitrary risk scores. These scores are often labelled as 'high risk' without explicit boundaries or thresholds for the underlying continuous risk estimates of patient-important outcomes. Moreover, it is apparent that prediction models are often misinterpreted as causal models by clinicians and researchers although they cannot be used as such. Additional challenges like the critical assessment of transportability and applicability of these prediction models, as well as their impact on clinical practice and patient outcomes, are not considered in the literature. Nevertheless, these instruments are promoted with claims regarding their ability to deliver more individualized and precise periodontitis treatment and prevention, purportedly resulting in improved patient outcomes. However, people with or without periodontitis deserve proper information about their risk of developing patient-important outcomes such as tooth loss or pain. The primary objective of disseminating such information should not be to emphasize assumed treatment efficacy, hype individualization of care, or promote business interests. Instead, the focus should be on providing individuals with locally validated and regularly updated predictions of specific risks based on readily accessible and valid key predictors (e.g. age and smoking).

Advancing Universal Oral Health Coverage via Person-Centred Outcomes

The World Health Organization member states proposed a comprehensive "Global Strategy on Oral Health," which includes achieving universal oral health coverage by 2030. Challenges and barriers, including persistent inequalities, will hamper the achievement of universal oral health coverage. In low- and middle-income countries, the oral health of a large proportion of the population has been neglected, increasing oral health inequalities. In high-income countries, some receive excessive dental treatment, whilst particularly those with higher needs receive too little dental care. Therefore, an analysis of individual countries' needs, encompassing the training of oral health professionals in a new philosophy of care and attention and the optimisation of the existing resources, is necessary. Distancing from a person-centred focus has prompted individual and societal issues, including under-/overdiagnosis and under-/overtreatment. The person-centred approach considers the perceptions, needs, preferences, and circumstances of individuals and populations. Patient-reported outcome measures, such as self-rated and -reported health, reflect an individual's overall perception of health and are designed to mediate human biology (ie, the disease) and psychology. The usage of patient-reported outcome measures in dentistry to place the individual at the centre of treatment is delayed compared to other areas. This paper discusses some challenges and potential solutions of patient-reported outcome measures in dentistry for achieving universal oral health coverage.

Justification for the 2017 periodontitis classification in the light of the Checklist for Modifying Disease Definitions: A narrative review

Once a while, disease classifications have needed revision because new knowledge has accumulated, and new technologies and better treatments have emerged. Changes made to disease classifications should be trustworthy and openly justified. The periodontitis definition and classification system was changed in 2017 by the 'World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions'. The workshop, comprising clinicians and researchers, resulted in the production of a 23-article special issue that introduced the new definitions and classifications of periodontitis. In this narrative review, we critically review how the changes made to the periodontitis definition and classification were justified in the light of the Checklist for Modifying Disease Definitions. Under each of the eight items of the checklist, we have discussed how the item was or could have been considered in the light of the checklist and its guidance. In our view, the new definition and classification of periodontitis was presented in an understandable way, even though the changes from the previous definition were not made visible. However, the issues of (1) estimated changes in prevalence or incidence, (2) triggers for the change, (3) prognostic ability, (4) repeatability or reproducibility, (5) incremental benefits, (6) incremental harms or (7) net benefits and harms related to the introduction of new classification were not considered in the way suggested in the checklist. Thereby, a balanced assessment of potential benefits and harms associated with the new periodontitis classification system was not presented, and to a large extent it remains unknown if the use of the new classification system will provide more net benefits to patients and to the community than previous systems. It is our view that patients and societies deserve transparent and balanced assessments of the potential benefits and harms associated with the periodontitis classification. Importantly, these should reflect the values and preferences also of the patients and the wider community and consider the impact on resource usage.

Effects of universal oral healthcare coverage in an adult population: A long-term nationwide natural experiment

OBJECTIVES

A large and long-term natural experiment occurred in Finland from the late 1980s-2000, when adults' entitlement to subsidized oral healthcare was strongly dependent on the arbitrary classification based on their year of birth: people born in 1956 or later were entitled to subsidized care, while people born before 1956 were not. The aim of this study was to investigate the effect of this expanded universal oral healthcare coverage on service use and oral health outcomes.

METHODS

Data from annual nationally representative cross-sectional postal surveys among 15-64-year-olds between 1990 and 2014 were used. For this study, the following outcome variables were formed: experiencing toothache during the past month (yes/no), the number of missing teeth with three different thresholds (over 10, over 5 or at least 1 missing tooth), brushing more than once a day and the number of visits to the dentist. Regression discontinuity plots and bias-corrected local polynomial regression discontinuity estimators measuring the effect of the extended universal coverage on the outcomes at the year-of-birth cut-off of 1956 were generated separately from the data from 1990 to 2000 and from 2002 to 2014.

RESULTS

Between 1990 and 2000, the number of visits to the dentist (0.2 visits, 95% CI, confidence intervals: -0.03; 0.43) and the proportion of those who visited the dentist during the past 12 months (4.2%, 95% CI: 0.1%; 8.3%) increased at the year-of-birth cut-off of 1956. There were minor drops (1.5%-1.9%) in the number of missing teeth across all thresholds (over 10, over 5, or at least 1 missing teeth) at the cut-off. Analyses with the data from the surveys from 2002 to 2014 showed that there were no discontinuities in these outcomes at the cut-off of 1956. Regression discontinuity estimates related to toothache experience and toothbrushing frequency were inconclusive due to high variability in the underlying data and the likely small effect of the more universal coverage on these outcomes.

CONCLUSIONS

The current study provided evidence of the beneficial effects of universal oral healthcare coverage on the oral healthcare service use and teeth preservation from a large and long-term natural experiment occurred in Finland from the late 1980s to 2000.

Reporting of costs and economic impacts in randomized trials of de-implementation interventions for low-value care: a systematic scoping review

BACKGROUND

De-implementation of low-value care can increase health care sustainability. We evaluated the reporting of direct costs of de-implementation and subsequent change (increase or decrease) in health care costs in randomized trials of de-implementation research.

METHODS

We searched MEDLINE and Scopus databases without any language restrictions up to May 2021. We conducted study screening and data extraction independently and in duplicate. We extracted information related to study characteristics, types and characteristics of interventions, de-implementation costs, and impacts on health care costs. We assessed risk of bias using a modified Cochrane risk-of-bias tool.

RESULTS

We screened 10,733 articles, with 227 studies meeting the inclusion criteria, of which 50 included information on direct cost of de-implementation or impact of de-implementation on health care costs. Studies were mostly conducted in North America (36%) or Europe (32%) and in the primary care context (70%). The most common practice of interest was reduction in the use of antibiotics or other medications (74%). Most studies used education strategies (meetings, materials) (64%). Studies used either a single strategy (52%) or were multifaceted (48%). Of the 227 eligible studies, 18 (8%) reported on direct costs of the used de-implementation strategy; of which, 13 reported total costs, and 12 reported per unit costs (7 reported both). The costs of de-implementation strategies varied considerably. Of the 227 eligible studies, 43 (19%) reported on impact of de-implementation on health care costs. Health care costs decreased in 27 studies (63%), increased in 2 (5%), and were unchanged in 14 (33%).

CONCLUSION

De-implementation randomized controlled trials typically did not report direct costs of the de-implementation strategies (92%) or the impacts of de-implementation on health care costs (81%). Lack of cost information may limit the value of de-implementation trials to decision-makers.

TRIAL REGISTRATION

OSF (Open Science Framework): https://osf.io/ueq32 .

Transparency of COVID-19-related research: A meta-research study

BACKGROUND

We aimed to assess the adherence to five transparency practices (data availability, code availability, protocol registration and conflicts of interest (COI), and funding disclosures) from open access Coronavirus disease 2019 (COVID-19) related articles.

METHODS

We searched and exported all open access COVID-19-related articles from PubMed-indexed journals in the Europe PubMed Central database published from January 2020 to June 9, 2022. With a validated and automated tool, we detected transparent practices of three paper types: research articles, randomized controlled trials (RCTs), and reviews. Basic journal- and article-related information were retrieved from the database. We used R for the descriptive analyses.

RESULTS

The total number of articles was 258,678, of which we were able to retrieve full texts of 186,157 (72%) articles from the database Over half of the papers (55.7%, n = 103,732) were research articles, 10.9% (n = 20,229) were review articles, and less than one percent (n = 1,202) were RCTs. Approximately nine-tenths of articles (in all three paper types) had a statement to disclose COI. Funding disclosure (83.9%, confidence interval (CI): 81.7-85.8 95%) and protocol registration (53.5%, 95% CI: 50.7-56.3) were more frequent in RCTs than in reviews or research articles. Reviews shared data (2.5%, 95% CI: 2.3-2.8) and code (0.4%, 95% CI: 0.4-0.5) less frequently than RCTs or research articles. Articles published in 2022 had the highest adherence to all five transparency practices. Most of the reviews (62%) and research articles (58%) adhered to two transparency practices, whereas almost half of the RCTs (47%) adhered to three practices. There were journal- and publisher-related differences in all five practices, and articles that did not adhere to transparency practices were more likely published in lowest impact journals and were less likely cited.

CONCLUSION

While most articles were freely available and had a COI disclosure, adherence to other transparent practices was far from acceptable. A much stronger commitment to open science practices, particularly to protocol registration, data and code sharing, is needed from all stakeholders.

Reporting of absolute and relative risk measures in oral health and cardiovascular events studies: A systematic review

OBJECTIVES

To understand the magnitude of risk of health events, such as cardiovascular diseases (CVD), related to poor oral health, both relative and absolute risk measures should be reported. Our aim was to investigate the extent to which absolute and relative measures of risk are reported in longitudinal studies that assess the association between oral health indicators (OHIs) and CVD.

METHODS

A systematic search of longitudinal studies investigating the association of any OHI with CVD was carried out using the Embase, Medline and Cochrane library databases. The search covered each database from its inception date to August 2021. Data about reporting relative and absolute risks of the relationship between CVD and OHI from the abstract were extracted. If the relative risk for OHIs and CVD was reported in the abstract, then the underlying absolute risks were searched from the full text, and it was assessed whether it was similarly adjusted for confounding than was the relative risk in the abstract.

RESULTS

One hundred-six articles were included. From these, 85 (80%) studies reported the association of OHIs and CVD with one or more relative risks in the abstract. Of those 85 studies, the underlying absolute risks were accessible or calculable from the abstract or full text of 60 studies. However, of these 60 studies, in only 10 (12%), the underlying absolute risks were similarly adjusted, as were the relative risks in the abstract. The absolute risks of CVD by OHIs were rarely reported without corresponding relative risks in the abstract (n = 2, 2%). Median absolute risk difference in the CVD risk between exposure levels to which the first relative risk in the abstract referred was 1.8% (interquartile range 0.6-4.6, n = 63).

CONCLUSIONS

Focusing on relative risks over absolute risks was a common practice in literature. Reporting similarly adjusted underlying absolute risks of relative risks was rare in most studies, despite those being helpful for comprehending the magnitude of CVD-risk increase related to poor oral health. Current reporting practices could lead to an overinterpretation of risk increase of CVD related to poor oral health.

Research transparency in dental research: A programmatic analysis

We assessed adherence to five transparency practices-data sharing, code sharing, conflict of interest disclosure, funding disclosure, and protocol registration-in articles in dental journals. We searched and exported the full text of all research articles from PubMed-indexed dental journals available in the Europe PubMed Central database until the end of 2021. We programmatically assessed their adherence to the five transparency practices using a validated and automated tool. Journal- and article-related information was retrieved from ScimagoJR and Journal Citation Reports. Of all 329,784 articles published in PubMed-indexed dental journals, 10,659 (3.2%) were available to download. Of those, 77% included a conflict of interest disclosure, and 62% included a funding disclosure. Seven percent of the articles had a registered protocol. Data sharing (2.0%) and code sharing (0.1%) were rarer. Sixteen percent of articles did not adhere to any of the five transparency practices, 29% adhered to one, 48% adhered to two, 7.0% adhered to three, 0.3% adhered to four, and no article adhered to all five practices. Adherence to transparency practices increased over time; however, data and code sharing especially remained rare. Coordinated efforts involving all stakeholders are needed to change current transparency practices in dental research.

Association of service use with subjective oral health indicators in a freedom of choice pilot

OBJECTIVES

A freedom of choice pilot provided access to private oral health care services without queuing and with fixed public service-fees for participants in Tampere region, Finland in 2018-2019. The aim of this study was to investigate how use of oral health care services differed by demographics, socioeconomic status, dental fear, and self-reported oral health in this pilot.

MATERIAL AND METHODS

SMS-messages including a link to online questionnaire were sent to participants who had booked an appointment, and to those who had not booked an appointment despite registering to pilot. We categorized participants to (1) those who had booked their first appointment before receiving SMS (visitors), (2) those who booked an appointment after receiving the SMS-message (late-visitors), and (3) those who had not booked an appointment during pilot (nonvisitors). We used regression analysis to estimate the association of age, gender, dental fear, economic situation, Oral Health Impact Profile-14-severity (oral health-related quality of life [OHRQoL]), self-reported oral health and need for oral health care (exposures) with oral health care service use during the pilot (outcome).

RESULTS

Out of 2300 participants, 636 (28%) responded. Late-visitors were more likely older and reported more likely need for oral health care, poorer oral health and OHRQoL than visitors or nonvisitors. Nonvisitors were younger and had better OHRQoL than the others. The differences in the service use by gender, economic situation, and dental fear were small.

CONCLUSIONS

Service use during the pilot depended on the subjective oral health. Our findings highlight the potential of reminders in increasing care use among those with perceived need for services.

Randomized controlled trials in de-implementation research: a systematic scoping review

BACKGROUND

Healthcare costs are rising, and a substantial proportion of medical care is of little value. De-implementation of low-value practices is important for improving overall health outcomes and reducing costs. We aimed to identify and synthesize randomized controlled trials (RCTs) on de-implementation interventions and to provide guidance to improve future research.

METHODS

MEDLINE and Scopus up to May 24, 2021, for individual and cluster RCTs comparing de-implementation interventions to usual care, another intervention, or placebo. We applied independent duplicate assessment of eligibility, study characteristics, outcomes, intervention categories, implementation theories, and risk of bias.

RESULTS

Of the 227 eligible trials, 145 (64%) were cluster randomized trials (median 24 clusters; median follow-up time 305 days), and 82 (36%) were individually randomized trials (median follow-up time 274 days). Of the trials, 118 (52%) were published after 2010, 149 (66%) were conducted in a primary care setting, 163 (72%) aimed to reduce the use of drug treatment, 194 (85%) measured the total volume of care, and 64 (28%) low-value care use as outcomes. Of the trials, 48 (21%) described a theoretical basis for the intervention, and 40 (18%) had the study tailored by context-specific factors. Of the de-implementation interventions, 193 (85%) were targeted at physicians, 115 (51%) tested educational sessions, and 152 (67%) multicomponent interventions. Missing data led to high risk of bias in 137 (60%) trials, followed by baseline imbalances in 99 (44%), and deficiencies in allocation concealment in 56 (25%).

CONCLUSIONS

De-implementation trials were mainly conducted in primary care and typically aimed to reduce low-value drug treatments. Limitations of current de-implementation research may have led to unreliable effect estimates and decreased clinical applicability of studied de-implementation strategies. We identified potential research gaps, including de-implementation in secondary and tertiary care settings, and interventions targeted at other than physicians. Future trials could be improved by favoring simpler intervention designs, better control of potential confounders, larger number of clusters in cluster trials, considering context-specific factors when planning the intervention (tailoring), and using a theoretical basis in intervention design.

REGISTRATION

OSF Open Science Framework hk4b2.

The use of the phrase "data not shown" in dental research

OBJECTIVE

The use of phrases such as "data/results not shown" is deemed an obscure way to represent scientific findings. Our aim was to investigate how frequently papers published in dental journals use the phrases and what kind of results the authors referred to with these phrases in 2021.

METHODS

We searched the Europe PubMed Central (PMC) database for open-access articles available from studies published in PubMed-indexed dental journals until December 31st, 2021. We searched for "data/results not shown" phrases from the full texts and then calculated the proportion of articles with the phrases in all the available articles. From studies published in 2021, we evaluated whether the phrases referred to confirmatory results, negative results, peripheral results, sensitivity analysis results, future results, or other/unclear results. Journal- and publisher-related differences in publishing studies with the phrases in 2021 were tested with Fisher's exact test using the R v4.1.1 software.

RESULTS

The percentage of studies with the relevant phrases from the total number of studies in the database decreased from 13% to 3% between 2010 and 2020. In 2021, out of 2,434 studies published in 73 different journals by eight publishers, 67 (2.8%) used the phrases. Potential journal- and publisher-related differences in publishing studies with the phrases were detected in 2021 (p = 0.001 and p = 0.005, respectively). Most commonly, the phrases referred to negative (n = 16, 24%), peripheral (n = 22, 33%) or confirmatory (n = 11, 16%) results. The significance of unpublished results to which the phrases referred considerably varied across studies.

CONCLUSION

Over the last decade, there has been a marked decrease in the use of the phrases "data/results not shown" in dental journals. However, the phrases were still notably in use in dental studies in 2021, despite the good availability of accessible free online supplements and repositories.

Dental Research Data Availability and Quality According to the FAIR Principles

According to the FAIR principles, data produced by scientific research should be findable, accessible, interoperable, and reusable-for instance, to be used in machine learning algorithms. However, to date, there is no estimate of the quantity or quality of dental research data evaluated via the FAIR principles. We aimed to determine the availability of open data in dental research and to assess compliance with the FAIR principles (or FAIRness) of shared dental research data. We downloaded all available articles published in PubMed-indexed dental journals from 2016 to 2021 as open access from Europe PubMed Central. In addition, we took a random sample of 500 dental articles that were not open access through Europe PubMed Central. We assessed data sharing in the articles and compliance of shared data to the FAIR principles programmatically. Results showed that of 7,509 investigated articles, 112 (1.5%) shared data. The average (SD) level of compliance with the FAIR metrics was 32.6% (31.9%). The average for each metric was as follows: findability, 3.4 (2.7) of 7; accessibility, 1.0 (1.0) of 3; interoperability, 1.1 (1.2) of 4; and reusability, 2.4 (2.6) of 10. No considerable changes in data sharing or quality of shared data occurred over the years. Our findings indicated that dental researchers rarely shared data, and when they did share, the FAIR quality was suboptimal. Machine learning algorithms could understand 1% of available dental research data. These undermine the reproducibility of dental research and hinder gaining the knowledge that can be gleaned from machine learning algorithms and applications.

Transparency of COVID-19-Related Research in Dental Journals

Objective

We aimed to assess the adherence to transparency practices (data availability, code availability, statements of protocol registration and conflicts of interest and funding disclosures) and FAIRness (Findable, Accessible, Interoperable, and Reusable) of shared data from open access COVID-19-related articles published in dental journals available from the Europe PubMed Central (PMC) database.

Methods

We searched and exported all COVID-19-related open-access articles from PubMed-indexed dental journals available in the Europe PMC database in 2020 and 2021. We detected transparency indicators with a validated and automated tool developed to extract the indicators from the downloaded articles. Basic journal- and article-related information was retrieved from the PMC database. Then, from those which had shared data, we assessed their accordance with FAIR data principles using the F-UJI online tool (f-uji.net).

Results

Of 650 available articles published in 59 dental journals, 74% provided conflicts of interest disclosure and 40% funding disclosure and 4% were preregistered. One study shared raw data (0.15%) and no study shared code. Transparent practices were more common in articles published in journals with higher impact factors, and in 2020 than in 2021. Adherence to the FAIR principles in the only paper that shared data was moderate.

Conclusion

While the majority of the papers had a COI disclosure, the prevalence of the other transparency practices was far from the acceptable level. A much stronger commitment to open science practices, particularly to preregistration, data and code sharing, is needed from all stakeholders.

Oral health care quality as viewed by leading dentists and their superiors - a qualitative study

OBJECTIVE

The aim was to investigate how leading dentists and their superiors view oral health care quality, as they are in key positions to pursue high-quality care.

MATERIALS AND METHODS

We interviewed five leading dentists and three of their superiors from Southern Finland via semi-structured telephone interviews including themes based on the Institute of Medicine's six quality dimensions. The material was analysed using theory-driven content analysis.

RESULTS

Participants divided safety into occupational, instrumental and patient safety and considered timeliness as timing treatment clinically correctly. They also linked timeliness to patient-centeredness with wider opening-hours and quick access to care. Effective care was considered as a prerequisite for efficiency. Participants saw effectiveness as treating the illness, not the number of treatment measures. Leading dentists took survival time of fillings and cost per operation as a measurement of efficiency, and the superiors measured efficiency by the number of treated patients or visits. The leading dentists considered the equal treatment of patients, whereas the superiors took the amount of care provided with public resources and co-workers into consideration.

CONCLUSIONS

The participants shared similar views of oral health care quality which should enable cooperation. Observed minor differences relate to professional background and leading positions.

Statements considering intervention effects in Finnish clinical practice guidelines: Recommending interventions with non-numeric effect-sizes or unspecified outcomes

RATIONALE, AIMS AND OBJECTIVES

Representation of benefits and harms associated with specific interventions in an understandable and comparable way is crucial for informed decision making that clinical practice guidelines (CPGs) aim to enhance. Therefore, we investigated how statements concerning the effects of interventions considered and described benefits and harms, magnitude of effect and its uncertainty, numeric and non-numeric information, and outcomes in Finnish CPGs.

METHODS

We selected 10 CPGs on common diseases and risk factors published by The Finnish Medical Society, Duodecim. All the statements which were graded with the level of evidence from high to very low (levels A-D) were included in analyses. From these statements, assessments were made regarding whether the statement considered benefits or harms, whether relative or absolute numeric measures were shown, whether the statement supported or was against the intervention considered, and what outcome was reported.

RESULTS

Of the 10 CPGs, 448 statements were assessed. Most of the statements of effects considered intervention benefits (87%) rather than harms. Half of the statements considering harms were represented in a way that supported the intervention. Most of the statements (94%) did not include numeric estimates of magnitude of the effect. When numeric estimates of magnitude of the effect were present, they were most frequently relative measures and were typically placed in a statement considering (a) intervention benefits with a primary outcome, (b) given the grade of A for level of evidence, and (c) that supported the use of intervention.

CONCLUSIONS

In the Finnish CPGs, the statements were rarely framed with both absolute and relative numeric measures of an intervention's effect. Harms were rarely reported with a grade indicating the level of evidence. The users of CPGs would benefit from more consistent and understandable framing of statements considering both benefits and harms of interventions.

Verbal communication of effect-sizes, possible comparators, and uncertainty of evidence in the Finnish clinical practice guidelines: Omitting effect-sizes and comparators without expressing much uncertainty

RATIONALE, AIMS, AND OBJECTIVES

Our aim was to investigate verbal representations of intervention effect-size, uncertainty of evidence, and possible intervention comparators in statements concerning effects of interventions in Finnish clinical practice guidelines.

METHOD

We selected 10 clinical practice guidelines on common diseases and risk factors published by The Finnish Medical Society Duodecim. All the statements that considered beneficial effects of interventions and that were graded with a level of evidence (levels A, high, to D, very low) were included in analyses. We assessed whether the statements verbally represented intervention effect-size, uncertainty of evidence or a possible comparator, and the reported outcome.

RESULTS

Of 385 statements, verbal representation of beneficial effect-sizes occurred in 25 (6%) statements. Most (72%) statements indicated that intervention had a beneficial effect, but did not specify effect-size. Less than half (42%) of the statements represented uncertainty verbally. Comparisons to placebo or no-treatment were rare (3%) and 18% of the statements compared interventions to other treatments. Against instructions, a considerable part (35%) of statements with B-level evidence did not represent uncertainty.

CONCLUSION

Communicating beneficial intervention effects, effect-sizes, possible comparators, and uncertainty of evidence require much broader attention in the clinical practice guideline context.

Age-Period-Cohort Analysis of Toothbrushing Frequency in Finnish Adults: Results From Annual National Cross-Sectional Surveys From 1978 to 2014

Objectives

No previous study has analysed age-, period-, and cohort-related long-term trends in toothbrushing frequency among adults using a nationally representative data set. Our aim was to study age, period, and cohort effects on toothbrushing among 15- to 64-year-olds in Finland from 1978 to 2014.

Methods

Data were gathered by nationally representative random cross-sectional samples of 15- to 64-year-old Finns annually from 1978 to 2014, during which response rates decreased from 84% to 53%. The final pooled sample size was 119,665. An age-period-cohort model was used to separate the effects of age, period, and cohort on trends in men's and women's toothbrushing frequency.

Results

From 1978 to 2014, the proportion of respondents who brushed at least twice a day or once a day increased from 42% to 66% and from 83% to 95%, respectively. The proportion of respondents who brushed at least twice a day increased from 27% to 53% among men and from 60% to 75% among women. Increases in at least once-a-day toothbrushing were smaller in both sexes, and in women the increase was minimal over the study years. The increase in toothbrushing frequency occurred particularly among those older than 40 years of age. In men, toothbrushing frequency increased steadily cohort by cohort (cohort effect) and within a single cohort as men in the cohort got older (longitudinal age trend). Instead, in women the cohort effect and longitudinal age trend in toothbrushing were smaller at both frequency thresholds.

Conclusions

On the population level, favourable changes in toothbrushing habits occurred among adult Finns from 1978 to 2014, especially in men.

Is the technical quality of root fillings associated with socioeconomic status?

Background

Socioeconomically better-off tend to receive better care, and to benefit more from care they receive, than the less well-off. The technical quality of root fillings can be assessed radiographically. Our aim was to investigate differences in the technical quality of root fillings according to socioeconomic status not studied before.

Methods

In the Finnish Health 2000 Survey, a sample of 8 028 over 29-year-old adults was selected by a stratified two-staged cluster sampling. Of these, 6 115 (76%) underwent panoramic radiography. A total of 7 986 endodontically treated teeth were detected among 3 905 participants. The criterion for a technically inadequate root filling was a distance from the root filling to the root apex of over 3 mm or material over the apex. Education, employment status and household income were used as measures of socioeconomic status. Differences in the quality of root fillings according to socioeconomic status were investigated using the Multiple Additive Regression Tree mediation analysis, taking into account age, gender and tooth type of the root filled tooth.

Results

Almost half (47%) of the root fillings were inadequate. Root filling quality was associated particularly with age of the participant and type of tooth. Mediation analysis showed that among the over 64-year-olds, higher education or income were associated with a slightly higher probability of inadequate root filling quality (ORs 1.15-1.20, p < 0.05). Among the under 65-year-olds, age of the participant and type of tooth explained the observed variations in root filling quality according to socieconomic status, and socioeconomic status had no influence (ORs 0.99-1.02, p > 0.05).

Conclusions

Those in a lower socioeconomic status had not received poorer endodontic treatment quality. It seems that those in a lower socioeconomic status are not prone to receive poorer quality care in endodontic setting, that they tend to receive in longer and more socially complex treatments.

Key messages

Variations in the technical quality of root fillings by socioeconomic status has not been studied. Lower socioeconomic status was not associated with poorer technical quality of root fillings.

Is the technical quality of root fillings associated with socioeconomic status? A cross-sectional study among Finnish adults

We investigated differences in the technical quality of root fillings according to socioeconomic status. In the Finnish Health 2000 Survey, which comprised a sample of 8,028 adults aged over 29 yr, 6,115 underwent panoramic radiography. A total of 7,986 endodontically treated teeth were detected among 3,095 participants. The criterion for a technically inadequate root filling was a distance from the root filling to the root apex of over 3 mm or a filling extruding beyond the apex. Educational level, employment status, and income were the measures of socioeconomic status. Differences in the frequency of inadequate root fillings according to socioeconomic status were investigated using a multilevel logistic mixed-effects model taking into account age, gender, number of teeth, and type of root filled tooth. Almost half (46%) of the root fillings were inadequate. Among the over 64-yr-olds, higher education and higher income were associated with a higher probability of having an inadequate root filling. Among the under 65-yr-olds, socioeconomic status was not associated with root filling quality. Contrary to expectation, lower socioeconomic status was not associated with poorer endodontic treatment quality; however, higher income and higher education was associated with higher odds for inadequate root fillings among the over 64-yr-olds.

Adult Finns' perceptions about communication with the dentist during their latest visit

OBJECTIVES

The aim of this study was to investigate adult Finns' perceptions about communication with the dentist during their latest visit in three aspects: receiving adequate information about health status and care, being listened to and shown interest by the dentist, and being able to influence the treatment decisions.

METHODS

Data were taken from the Health 2011 Survey (BRIH8901). A representative sample (n = 5806) of adult Finns aged over 29 years old was interviewed or alternatively filled in a questionnaire. Basic descriptive tabulations, Rao-Scott chi-square tests and logistic regression analyses were used to study how socioeconomic status, perceived oral health and oral Health care variables are associated with the three aspects of communication with the dentist.

RESULTS

Most (85%-90%) adult Finns felt that, during their latest visit to a dentist, they had received adequate information, were listened to and shown interest by their dentist, and that they had been able to influence the treatment decisions. Those who perceived poor oral health, felt visiting dentist somewhat frightening, were in a difficult economic situation, visited a public dentist, or tended to visit oral Health care services irregularly, felt more often that there was a deficit in communication with the dentist.

CONCLUSIONS

In 2011, most adult Finns did not report any deficit in communication with the dentist during their latest visit. Oral Health care professionals should focus more on communicating with patients who have economic problems, poor oral health, dental fear or a problem-oriented visiting pattern.

Education-related inequality in restorative dental treatment need over 11 years in two areas of Finland

OBJECTIVES

This study aimed to analyse education-related inequality in restorative dental treatment need among adults aged 30 years and older living in Northern and Southern Finland in 2000 and 2011.

METHODS

Data were taken from the Health 2000 and 2011 population-based follow-up surveys, including information gathered by interviews and clinical dental examination. Final effective sample sizes were 2423 people in 2000 and 1192 people in 2011. Restorative dental treatment need was measured with number of decayed and/or fractured teeth (DT + FrT). Education-related inequality in number of DT + FrT and factors explaining it were analysed using the Poisson regression analysis, relative index of inequality and slope index of inequality.

RESULTS

Average number of DT + FrT decreased from 2000 to 2011. Absolute and relative education-related inequalities in them decreased approximately 50% and 25% from 2000 to 2011, respectively. Tooth brushing frequency and time since last dental visit explained approximately 30%-40% of the education-related inequality. The contribution of time since last dental visit to the education-related inequality was smaller in 2011 than in 2000.

CONCLUSIONS

It seems that, from 2000 to 2011, the need for restorative dental treatment decreased simultaneously with the education-related inequality in it among adults aged 30 years and older living in Northern and Southern Finland.

Income-related inequality in perceived oral health among adult Finns before and after a major dental subsidization reform

Objectives In Finland, a dental subsidization reform, implemented in 2001-2002, abolished age restrictions on subsidized dental care. The aim of this study was to investigate income-related inequality in the perceived oral health and its determinants among adult Finns before and after the reform. Materials and methods Three identical cross-sectional nationally representative postal surveys, concerning perceived oral health and the use of dental services among people born before 1971, were conducted in 2001 (n = 2157), in 2004 (n = 1814) and in 2007 (n = 1671). Three measures of perceived oral health were used: toothache or oral discomfort during the past 12 months, current need for dental care and self-reported oral health status. Concentration index was used to analyse the income-related inequalities. Its decomposition was used to study factors related to the inequalities. Results The proportion of respondents reporting need for dental care decreased from 2001 to 2007, while no changes were seen in reports of toothache or self-reported oral health status. Income-related inequalities in reports of toothache and perceived need for care widened, while the inequality in self-reported oral health remained stable. Most of the inequalities were related to income itself, perceived general health and the time since the last visit to dental care. Conclusions It seems that the income-related inequalities in perceived oral health remained or even widened after the reform.

Income-related inequality and inequity in the use of dental services in Finland after a major subsidization reform

OBJECTIVES

In Finland, a major oral healthcare reform (OHCR), implemented during 2001-2002, opened the public dental services (PDS) and extended subsidies for private dental services to entire adult population. Before the reform, adults born earlier than 1956 were not entitled to use PDS nor did they receive any reimbursements for their private dental costs. We aimed to examine changes in the income-related inequality and inequity in the use of dental services among the adult Finns after the reform.

METHODS

Representative data from Finnish adults born in 1970 or earlier were gathered from three identical postal surveys concerning the use of dental services and subjective perceptions of oral health. Those surveys were conducted before the OHCR in 2001 (n = 1907) and after the OHCR in 2004 (n = 1629) and 2007 (n = 1509). We used concentration index and its decomposition to analyse income-related inequality and inequity in the use of dental services and factors associated with them.

RESULTS

Results showed that pro-rich inequality and inequity in the overall use of dental services narrowed from 2001 to 2004. However, between 2004 and 2007, pro-rich inequality and inequity widened, so it returned to a rather similar level in 2007 as it had been in 2001. Most of the pro-rich inequality and inequity were related to regular dental visiting habit and income level. While there was pro-poor inequality and inequity in the use of PDS, there was pro-rich inequality and inequity in the use of private dental services throughout the study years.

CONCLUSION

It seems that income-related inequality and inequity in the use of dental services narrowed only temporarily after the reform.