The reliability and validity of the Romanian rapid estimate of adult literacy in dentistry (RREALD-30)

OBJECTIVES

This study aimed to translate and adapt the Rapid Estimate of Adult Literacy in Dentistry (RREALD-30) instrument for Romanian urban adults and to test its reliability and validity for oral health literacy studies.

MATERIAL AND METHODS

The study examined urban adult patients (n = 224) who attended the dental school clinic at the Faculty of Dental Medicine, Bucharest. We collected data through face-to-face interviews utilising the REALD-30 instrument. The interviews enquired about the Oral Health Impact Profile (OHIP-14), background characteristics, oral health-related knowledge, visits to dentists and self-rated oral health status. We applied principal component analysis for factor structure and Item Response Theory models to discriminate ability. A structural equation model (SEM) evaluated whether knowledge, perceived oral health, and visits to the dentist mediate the effect of RREALD on OHIP-14.

RESULTS

Of the 224 participants, 113 (50.4%) were males. The internal consistency of the RREALD-30 measured by Cronbach's alpha was 0.88. The test-retest reliability was excellent (Spearman's correlation coefficient 0.98, ICC 0.90). RREALD-30 exhibited good concurrent and predictive validity. SEM demonstrated that RREALD mediated the effect of visits to dentist on OHIP-14.

CONCLUSION

The RREALD-30 proved satisfactory psychometric properties and may serve to evaluate dental health literacy among Romanian adults.

Information retrieval, critical appraisal and knowledge of evidence-based dentistry among Finnish dental students

BACKGROUND

One of the core skills of competent dentist is the ability to search and analyse high-quality evidence. Problems in understanding the basic aspects of knowledge-based information may impede its implementation into clinical practice. We examined how Finnish dental students acquire scientific information and how familiar they are with methods for evaluating scientific evidence related to clinical questions.

METHODS

All fifth-year dental students (n = 120) at the three universities in Finland received a self-administered questionnaire.

RESULTS

The three most commonly used sources of information were colleagues, the commercial Health Gate Portal for dental practitioners and personal lecture notes. Although students rarely read scientific journals, they did find that they possess at least passable or even good skills in literature retrieval. Three questions related to the appraisal of evidence in dentistry revealed that students' knowledge of evidence-based dentistry was inadequate to critically evaluate clinical research findings.

CONCLUSION

Most students seem to lack knowledge of key methodological evidence-based terms. The present curricula in dental schools fail to encourage the students to search and acquire knowledge wider than their patients themselves do. Universities have the responsibility to teach dentists various methods of critical appraisal to cope with scientific information.

Does dental hygienist professional education meet the needs of working life? Educators' views

OBJECTIVE

The aim of this study was to describe the compatibility of dental hygienist education with working life from the perspective of their educators.

METHODS

We conducted a qualitative study among principal educators of dental hygienists in Finland in 2012-2013. The participants were leading educators of dental hygienists (n = 13) from the four Finnish education units. We used semi-structured interviews based on previous Nordic studies to collect the data and analysed them using inductive content analysis.

RESULTS

According to the educators, dental hygienists' skills at work are neither fully nor effectively utilized, even though their education meets the needs of working life quite well. The educators felt that hygienists' professional competence would prove more useful in health promotion and orthodontic measures and that the division of labour should be clearer. Clarifying this distinction in periodontal therapy could be improved.

CONCLUSION

Fully utilizing dental hygienists' competence in clinical work would benefit from further development. The content of dental hygienists' clinical work should be reassessed so as to utilize their skills more fully. The compatibility of dental hygienist education corresponds largely to the needs of future working life.

Oral health care-related beliefs among Finnish geriatric home care nurses

OBJECTIVES

The aim was to investigate beliefs about oral health care tasks among nursing staff caring for home-dwelling older people using the Nursing Dental Coping Beliefs (nursing DCBS) index.

METHODS

The study population comprised nursing staff working at the homes and sheltered accommodations of older people in Ylivieska, Finland (N = 141). The data were collected using the nursing DCBS index (five-point Likert scale).

RESULTS

On average, the nurses held moderate to high Oral health care beliefs, Internal locus of control beliefs and External locus of control beliefs, but low beliefs about Self-efficacy. The nurses with an earlier adjunct education scored lower for Oral health care beliefs on the factor Knowledge about preventing gum diseases (OR = 0.3, 95% CI: 0.1-0.9) than did the others. Regarding beliefs about External locus of control, the age group 31-49 years scored lower on the factor Retaining teeth as one ages (OR = 0.2, 95% CI: 0.1-0.7), but scored higher on the factor How to prevent dental diseases (OR = 5.6, 95% CI: 1.1-29.3) than did younger nurses (≤30 years). The nurses with only a nursing education showed significantly higher mean scores on the Self-efficacy factor Confidence of the need for dental knowledge than did those with an earlier adjunct education (P = 0.034).

CONCLUSIONS

The nursing staff mostly believed that oral diseases are preventable and teeth can be retained in advanced age, but failed to recognize the value of dental knowledge and had little confidence in their ability to manage oral diseases. Improving the oral health-related knowledge and self-efficacy beliefs of nursing staff will require additional oral health education.

Knowledge of and attitudes towards periodontal health among adults in Tehran

Determining what people know and believe about periodontal health and disease is important in order to establish prevention practices. This study aimed to assess knowledge of and attitudes towards periodontal health among adults in Tehran, Islamic Republic of Iran. We conducted a cross-sectional face-to-face interview survey in 2011 of 791 adults aged 18-50 years using a stratified, multistage sampling method. We recorded demographic characteristics including age, sex, education, marital status, employment and economic status (housing density). The lowest percentage of correct answers was related to the definition of dental plaque (11.6%) and the highest was for the role of the dental visit in prevention (92.8%). Female sex, university education and higher economic status were significantly associated with a higher mean score on periodontal health knowledge. The regression analysis showed that positive attitudes were associated with higher periodontal health knowledge and having university education. In this study positive attitudes towards prevention were related to better knowledge.

Tobacco use among Iranian dental students: a national survey

A national survey was conducted to provide up-to-date data on current and ever use of tobacco among Iranian dental students. All 4th-year students of 8 randomly selected dental schools were surveyed anonymously in December 2010 using the Global Health Professions Student Survey questionnaire. Of 325 participants, 54.2% were ever users of tobacco products (73.0% of males versus 44.4% of females); 50.8% had used waterpipes, 34.2% cigarettes and 9.3% other products. The most common age at first use was 20-24 years for both sexes. Current tobacco use was reported by 20.6% of respondents, cigarette smoking by 10.8% and waterpipe smoking by 15.8%. Regression models showed that current cigarette and waterpipe smoking were significantly associated with male sex but not with type of dental school (state/private). Current waterpipe smoking was also associated with age at first experience. In view of the important role of dentists in tobacco control, the prevention of tobacco use should be stressed among Iranian dental students.

Common Perceptions of Periodontal Health and Illness among Adults: A Qualitative Study

Objective. Our aim was to explore perceptions of periodontal health and illness and to examine attitudes and beliefs regarding prevention of gum diseases among Iranian adults. Methods. Our qualitative approach included focus-group discussions among adults aged 18 and above based on convenient and purposive sampling in Tehran. Transcripts of the four focus-group discussions were analyzed by two independent reviewers using a content analysis method. Results. Two major themes in the analyses emerged: the common perception of periodontal health and illness and the attitude towards prevention. The study demonstrated the subjects' good understanding of prevention of periodontal disease, but their lack of knowledge of the aetiology of the diseases, and an inability to differentiate aetiology, symptoms, and prevention of dental caries and periodontal disease. Conclusion. This study revealed a need for oral health education among Iranian adults to improve their knowledge and change their attitudes to achieve deeper understanding of the aetiology and prevention of periodontal disease. Health promotion programs should address misconceptions about prevention of gum disease.

Attitude towards preventive dentistry among Iranian senior dental students

OBJECTIVE

To investigate attitudes of Iranian senior dental students towards preventive dentistry in relation to their background factors and self-perceived competency in providing preventive care.

MATERIALS AND METHODS

In spring 2008, a questionnaire survey was conducted with all the senior dental students of seven randomly selected state dental schools in Iran. In addition to the respondents' age and gender, the voluntary questionnaire assessed the students' attitudes towards preventive dentistry by means of a seven-point semantic differential scale of nine qualities and their opposites, and their self-perceived competency in providing preventive care by five separate questions. To identify the underlying dimensions for attitude, a factor analysis with principle component method and varimax rotation was applied. Independent sample t-test served for statistical analysis. Of the 242 students receiving the questionnaire, 182 students (75%) responded. The mean age of the participants was 26 years and 42% of them were men.

RESULTS

Based on the factor analysis, which explained 60% of the total variance, two attitude dimensions were identified; the profession-related dimension and the health service-related dimension. Competency in giving preventive care in all the five specified areas was reported by 44% of the students with no significant gender differences. The mean for the dentist-related dimension was significantly higher among the students who reported competency in giving preventive care (P=0.005).

CONCLUSION

There is room for improvement in senior dental students' attitudes towards preventive dentistry. In order to create more positive attitudes for future dental professionals, there should be an early and sufficient exposure to preventive aspects of dentistry in the dental curricula.

Smoking and its determinants among Iranian dental students

OBJECTIVE

The objective of the present study was to investigate smoking habits of Iranian dental students in relation to their background characteristics and oral self-care (OSC).

SUBJECTS AND METHODS

A survey in the form of a questionnaire was conducted of 327 senior dental students in seven randomly selected state dental schools in Iran. In addition to smoking habits and background characteristics, the students were asked about OSC. A recommended level of OSC was defined as a combination of brushing at least twice a day, frequent use of fluoridated toothpaste, and eating sugary snacks less than daily. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). A total of 263 students (113 males and 150 females) completely answered the questions and were included in the analyses.

RESULTS

Of the 263 students, 59 (23%, 37 males and 22 females) reported current smoking (cigarette, pipe, or water pipe). Current smoking was associated with male gender (OR = 2.9, 95% CI = 1.4-5.6), level of father's education (OR = 1.4, 95% CI = 1.1-1.8), and OSC (OR = 4.4, 95% CI = 1.3-14.9).

CONCLUSION

Smoking among Iranian dental students is similar to their socioeconomic group, and is associated with the characteristics of their background, such as gender and father's level of education, as well as the quality of OSC. The results indicate a need to include smoking cessation education and public health activities in the dental curriculum to provide future health care professionals and role models for patients with adequate training in up-to-date patient management to control smoking.

Effect of directorial intervention on web-based student feedback

The Medical Faculty of the University of Helsinki decided to employ a web-based evaluation system as an integral and essential part of all courses beginning in the autumn term of 2006.

OBJECTIVES

To analyse the effects of the intervention on dental students' web-based responses at the University of Helsinki, Finland.

SUBJECTS AND METHODS

A previously developed web-based tool was used for all preclinical and clinical courses from the beginning of the 2006-2007 academic year. We analysed data sets of student feedback for all courses before (2005-2006) and after (2006-2007) the intervention. We then compared the quantity and quality of the students' feedback for the six standardised questions used in the evaluation, and calculated the means and standard deviations of values obtained with a Likert scale. The students' assessments in the open questions were categorised according to key issues.

RESULTS

Implementation of the system resulted in a considerable increase in student feedback: the mean response rate for the preclinical phase rose from 59% (SD 15.0; range 25-80) before the intervention to 90% (SD 9.6; range 72-100) after it. In the clinical phase, the response rates more than doubled from 34% (SD 15.9; range 9-69) to 73% (SD 12.9; range 45-100). The students' assessments showed no significant change despite the marked rise in response rates. The educators' positive attitude towards the students was appreciated (4.2-4.3) whereas the general goals for the courses in the clinical phase seemed unclear to the students (3.4) (P < 0.05).

CONCLUSIONS

Web-based evaluation as an integral part of all courses in the dental curriculum proved successful: shortly after the intervention, we observed a considerable increase in student feedback with no significant change in quality.

School-based intervention to promote preadolescents' gingival health: a community trial

OBJECTIVES

Evaluation of the effectiveness of a school-based oral health promotion intervention on preadolescents' gingival health.

METHODS

A community trial designed for a 3-month intervention study in a representative sample of 9-year-olds (n = 457) in 16 schools in Tehran, Iran. The schools were randomly assigned to three intervention groups and one control group, each group comprising two boys' and two girls' schools. The first group of children (n = 115) received intervention via class work, solving a set of puzzles containing oral health messages, under supervision of their health counsellor. The second group (n = 114), intervention via parents, included an oral health education leaflet and a brushing diary for supervising the child's tooth-brushing; the third group (n = 111) received a combination of both these interventions. The control group (n = 117) had no intervention. Effects of the intervention were assessed as changes in dental plaque and gingival bleeding. Improvements in gingival health were recorded when half of the index teeth with plaque at baseline became clean (acceptable oral hygiene) or when all index teeth with bleeding at baseline became healthy (healthy gingiva). Statistical analysis included chi square, anova, t-test, Number Needed to Treat (NNT) and generalized estimating equations (GEE).

RESULTS

At baseline, none of the children were free of plaque and all except for three boys had bleeding. After the trial, acceptable oral hygiene was more frequent in the parental-aid (P < 0.001) and the combined groups (P < 0.05), and healthy gingiva in both groups (P < 0.001) in comparison with the control group. Outcomes in the class-work group did not differ from those in the control group. The GEE models confirmed a strong intervention effect on healthy gingiva in both groups where parents were involved: parental-aid group (OR = 7.7, 95% CI: 2.2-27.7) and combined group (OR = 6.6, 95% CI: 2.0-22.1). In all intervention groups more girls than boys achieved healthy gingiva (OR = 2.5-2.6). Parents' education showed no impact on the outcome.

CONCLUSIONS

When a school-based oral health intervention involves parents it may result in a significant improvement in the gingival health of preadolescents with poor gingival health at baseline.

A cluster randomised trial of effectiveness of educational intervention in primary health care on early childhood caries

Early childhood caries (ECC) remains a serious problem in several developing and developed countries. This cluster randomised trial evaluated the impact of a 6-month educational intervention on ECC. The trial targeted 12- to 15-month-old children (n = 242) and their mothers in Tehran, Iran, visiting 18 public health centres, randomly selected and assigned to two intervention groups and one control group. At baseline, each mother was interviewed and each child underwent a dental examination of all teeth for the number of decayed teeth (dt) and of upper central incisors for the number of teeth with enamel caries (de). All mothers in the two intervention groups (A and B) received oral health instructions from the vaccination staff. In addition, group A received extra reminders. The outcome was defined as increments in the number of teeth with dt or de, as percentages of children developing new dt or de, and as the number needed to treat (NNT). No new de appeared in group A, the mean de increment in group B was 0.2 (SD = 0.6), and in the controls, it was 0.4 (SD = 0.7) (p < 0.05). The percentages of children developing new de were 0, 14, and 26%, respectively. No differences in dt increments were found. Regarding de, NNT for group A was 4 and for B 9; the figures for dt were 13 and 17, respectively. In conclusion, oral health education given to mothers by general health staff is a valuable tool to prevent caries in infants and toddlers.

Feeding habits as determinants of early childhood caries in a population where prolonged breastfeeding is the norm

OBJECTIVES

To investigate the impact of feeding habits and daytime sugar intake on the prevalence of early childhood caries in a population where prolonged breastfeeding is a norm.

METHODS

A cross-sectional study was carried out at 18 of 102 public health centers in Tehran. During a 4-day period at each center, between 20 and 35 children aged 1-3 years were enrolled, resulting in a sample of 504 children. In structured interviews, mothers were asked to give information about their child's feeding habits, daytime sugar intake, and their family's background. Sugar intake during the night was operationalized as separately calculated burdens of nighttime breastfeeding and bottle-feeding. Clinical dental examinations followed the World Health Organization criteria. Data analysis included chi-square test, t-test, ANOVA, and logistic regression modeling.

RESULTS

Of the children, 56% were solely breastfed (mean duration 16.6 months; 95% CI 16.0-17.2), 42% were both breastfed and bottle-fed, and 2% were solely bottle-fed. Mean duration of breastfeeding for the solely breastfed 24- to 36-month olds was 22.8 months (95% CI 21.8-23.9). At bedtime, 69% were breastfed, 11% bottle-fed, and 20% were not fed at all. With respect to feeding during the night, 72% of children were breastfed, 12% were bottle-fed with milk, 1% received a bottle with water, while 15% were not fed. Early childhood caries (ECC) occurred in 3-26% of the children, depending on age group (P < 0.001). The burden of milk-bottle feeding at night was a clear determinant for ECC (OR = 5.5) whereas breastfeeding per se, its duration, the burden of breastfeeding at night, and daytime sugar intake were not.

CONCLUSION

On account of its association with ECC, milk-bottle feeding at night should be limited, whereas prolonged breastfeeding appears to have no such negative dental consequences.

Influence of mothers' oral health knowledge and attitudes on their children's dental health

AIM

This was to evaluate the influence of mothers' oral health-related knowledge and attitudes on the tooth-brushing behaviour and dental health of their children and to compare the effect of these maternal aspects on child's oral health.

STUDY DESIGN AND METHODS

In 2005, an oral health study conducted among a random sample of 457 mother and child pairs in Tehran, Iran, used self-administered questionnaires to provide data on mothers' oral health-related knowledge and attitudes and children's tooth-brushing behaviour. Clinical data allowed assessment of dental status of the primary and permanent dentition.

STATISTICS

Chi-square test and binary logistic regression models were employed.

RESULTS

Generally, mothers had extensive knowledge of and positive attitudes towards oral health. Mothers' higher level of oral health knowledge and better attitude scores were associated with children's sound dentition (p<0.05), while only mothers' better attitude was associated with children's twice-daily tooth brushing (p=0.001). The multivariate analyses showed that children of mothers with higher attitude scores were more likely to brush their teeth twice daily (OR = 2.1; 95% CI 1.2 - 3.7) and have sound dentition (OR = 12.4; 95% CI 1.8 - 85.9). The models revealed that mother's knowledge per se had no effect on children's sound dental health, but showed an additive effect with mother's attitudes.

CONCLUSIONS

Because twice-daily tooth-brushing behaviour and sound dentition in 9-year-olds were associated with their mothers' positive oral health-related attitudes, in developing oral health promotion programs for children and adolescents, the considerable potential of mothers should be a major focus of oral health professionals.

Study motives and career choices of Iranian dental students

OBJECTIVES

To investigate the study motives and career choices of Iranian senior dental students in relation to their background factors.

SUBJECTS AND METHODS

During the spring term 2005, a questionnaire survey was administered to 327 senior dental students in seven randomly selected state dental schools in Iran. The questionnaire requested information on age, gender, parents' employment in dentistry, previous education and employment in dental hygiene, study motives, and career choices. Statistical analyses were made using independent sample t test, factor analysis, and binary logistic regression model.

RESULTS

Based on the factor analysis, which explained 73% of the total variance, five motive dimensions were identified: altruism and intellectual challenges, characteristics of the profession, social status and security, other person's recommendation, and failure to be admitted to other study programmes. The mean for the 'characteristics of the profession' dimension was lower among the students with at least one parent employed in dentistry (p = 0.03). The 'altruism and intellectual challenges' dimension was reported to be more influential by the students with background in dental hygiene (32 students) compared to the others (p < 0.001). Engaging in postgraduate studies was the first career preference of 189 (70%) of the respondents. Those with a background in dental hygiene were less inclined to enter postgraduate courses (p < 0.001), but more eager to be employed in either the public or the private sector (p < 0.001), and to enter the community oral health and research field (p < 0.001) than the others.

CONCLUSION

Personal characteristics and motives of the students play a major role in shaping their career preferences.

Disparities in oral health of children in Tehran, Iran

AIM

This was to investigate the association between parents' educational level and oral health of Iranian primary school children.

METHODS

Data came from the voluntary clinical examination in 2005 of a random sample of 459 third-year primary school children in the 16 schools in Tehran, together with a self-administered questionnaire regarding information on the educational level of the parents. The study used the dmft/DMFT values for dental status, and the CPI, and PI to assess periodontal condition.

STATISTICS

One-way ANOVA, Kruskal-Wallis and Mann-Whitney U tests were used.

RESULTS

The mean dmft value was 4.2 (SD+2.9) in boys and 3.4 (SD+2.6) in girls for the whole study group. The children of the low education parents had more dental caries than those of high education parents in both primary (p<0.01) and in permanent teeth (p<0.05). A strong association was found between high parental education and restorations in primary teeth (p<0.001), but only a trend for restorations in permanent teeth. Mean number of sextants with a CPI score 0 was significantly associated with parents' educational level (p<0.01).

CONCLUSION

The disparities in the oral health of children need to be considered when developing oral health promotion programmes.

Oral health behaviour of Iranian mothers and their 9-year-old children

PURPOSE

The present study examined associations between the oral health behaviour (OHB) of Iranian mothers and the OHB and oral health status of their children.

MATERIALS AND METHODS

In 2005, two self-administered questionnaires provided data on the OHB of a random sample of 9-year-old children (n = 459) and their mothers in Tehran, Iran. Brushing frequency, use of fluoridated toothpaste and number of sugary snacks between meals served as oral self-care (OSC) assessment criteria for both. A clinical examination was performed for children at school. DMFT/dmft values, the restoration index (RI) and the unmet treatment needs index (UTN) facilitated an assessment of children's dental status and treatment. Chi-square test, bivariate correlation, and binary logistic regression model were employed in these analyses.

RESULTS

Mother's OSC correlated with child's OSC (r = 0.18; p < 0.01). The reported children's brushing frequency correlated with mothers' brushing frequency (r = 0.2; p < 0.01). High maternal OSC levels were associated with lower dental treatment (DT) values in children (p < 0.01). Children's RI was positively and UTN negatively associated with mothers' OSC (p < 0.01). In the model, mothers' OSC (OR = 2.1) and female gender (OR = 2.1) were associated with children's OSC, while mothers' OSC was strongly associated with DT (OR = 11.0) and RI (OR = 34.0) in children.

CONCLUSIONS

Higher OSC levels of the surveyed mothers were reflected positively in the oral health status and behaviour of their offspring. The potential of mothers to play a significant role in the oral health of their children should be kept in mind when developing oral health promotion programmes.

Children's use of general practitioner services in the five Nordic countries

OBJECTIVE

To compare socioeconomic, sociodemographic, and living area differences in children's use of GP services in five Nordic countries from the 1980s to the 1990s and to analyse trends during the period.

DESIGN

Cross sectional population surveys using random samples comprising 3000 children aged 2-17 years were conducted in 1984 and 1996 in five Nordic countries. Time trends in use of GP services were studied in each country by age, sex, parents' highest level of education, and living area.

SETTING

Five Nordic countries, Denmark, Finland, Iceland, Norway, and Sweden in 1984 and 1996.

PARTICIPANTS

A total sample of 15 000 children aged 2-17 years. Altogether 3000 children were selected at random from the national population registers of the national bureaus of statistics in each country.

MAIN OUTCOME

Health services utilisation on the basis of responses to a questionnaire item asking whether the parents had consulted a GP with regard to their children's health during the previous three months.

MAIN RESULTS

The prevalence of children's utilisation of GP services varied from 14% in 1984 in Sweden to 28% in 1996 in Iceland. A clear time trend towards increasing utilisation of GP services (p<0.05) was found in all countries except in Denmark. Odds ratios for time trends (1984 = 1.00) varied from 1.22 (1.02 to 1.46) in Sweden to 1.92 (1.62 to 2.30) in Norway. After adjusting for independent variables, a statistically borderline significant declining utilisation trend (OR = 0.85 (0.70 to 1.03)) was found for Denmark.

CONCLUSION

Children's use of GP services has increased significantly in four of the five Nordic countries.

Changes and trends in attack distributions and progression of dental caries in three age cohorts in Finland

BACKGROUND

Several factors are claimed to have contributed to the decline in dental caries that has occurred over recent decades in many industrialised countries.

METHODS

A retrospective cohort design follow-up study of trends in dental caries in three age cohorts born a decade apart is reported from Finland. Subjects born in the 1960s, 1970s and 1980s (n = 1275) were monitored annually through their patient records, and changes in the distribution, extent and rate of caries attack (caries leading to restorations or extractions) were analysed. Logistic and Poisson regression techniques were employed to detect trends and Kaplan-Meier survival methods were used for the rate analyses.

RESULTS

A marked decrease in caries was observed and the proportion of disease-free subjects increased gradually towards the younger cohorts. Logistic regression analysis showed clear trends, in that the odds ratios (ORs) for the cohort effect were 8.93 [95% confidence interval (CI) = 7.95-10.04] and 4.32 (95% CI = 3.92-4.75) in the 1960 and 1970 cohorts, respectively, relative to the 1980 cohort, and that for the age (year) effect was 1.44 (95% CI = 1.42-1.46). Similar types of cohort and age effects (p < 0.0001) were found in the disease progression analyses. The rate analyses showed statistically highly significant differences between the three cohorts (p < 0.001) for both sexes. The caries decline was a lasting one, in spite of the delay in restorations observed in the youngest cohort.

DISCUSSION

The results indicate a vast and continuous trend in the incidence of dental caries leading to restorations and extractions. Significant changes in the rate and extent of disease progression have taken place, which will inevitably affect the future public health agenda.

Applying modern survival analysis methods to longitudinal dental caries studies

Before the 1960s, tooth-specific caries risk was reported to be highest at 2 to 4 years after eruption. We studied the tooth-specific caries risk in three contemporary age cohorts in Finland. All together, 4072 boys and girls were followed annually from age 6 to age 18+ years in three age cohorts born in the 1960s, 1970s, and 1980s. We used a survival model and Bayesian inferential methods in the statistical analyses to establish the secular changes during this period. The analysis was based on the caries risk in individual teeth as a function of tooth age instead of summary measures, such as DMFS values. Our first finding was a marked overall decrease of caries. Moreover, analyses of the 1960 and 1970 cohorts revealed that the risk in molar teeth was highest immediately after eruption; in the youngest cohort, however, the risks of individual teeth were so low that no such dependencies on tooth age could be established.

Timing of first fillings in the primary dentition and permanent first molars of asthmatic children

The aim of this study was to analyze the timing of first fillings posteruptively in a cohort comprising 51 asthmatic children receiving inhaled corticosteroids and living in three communities in Ostrobothnia, Finland. They had all been born in the 1980s and had had asthma check-ups in the local asthma policlinic. A group of 102 healthy age- and sex-matched children served as controls. A longitudinal survival analysis of the timing of the first filling in the primary teeth and first permanent molars was conducted retrospectively using data from the annual dental health records. The timing of the first fillings in permanent first molars showed no statistically significant differences between asthmatic and healthy children, but the filling increments in the primary molars were consistently higher in the asthmatic group; the difference for the upper first primary molars was, for instance, statistically significant (risk ratio = 2.565; 95% confidence interval = 1.333-4.935). More extractions because of caries were also performed on primary molars in the asthmatic children. The findings support the hypothesis that factors related to the asthmatic condition might increase the risk of caries. A longer surveillance time would be needed to evaluate the effect of asthma on the permanent dentition.

Effect of early restorations of permanent molars on filling increments of individual teeth

OBJECTIVES

The purpose of this work was to analyse longitudinally whether the placement of restorations on permanent molar teeth immediately after their eruption results in (a cohort with) higher filling increments in all individual teeth thereafter. The patient documents of 937 subjects born either in 1970-1971 or in 1980-1981 were analysed.

METHODS

The methods of survival analysis were employed. If any of the first permanent molar teeth had been restored in the course of tooth emergence, the person was assigned to the experimental group, and all the others were placed in the control group. Those in whom all the first permanent molar teeth had been restored at the time of emergence were compared with all the others.

RESULTS

Early restoration of any permanent molar indicated higher filling increments in all the other molar teeth. The differences between the groups with regard to the first and second molar teeth were statistically highly significant (e.g. D.17 for the girls: log-rank chi 2 = 32.8, p = 0.0001 and Wilcoxon chi 2 = 28.7, p = 0.0001). The differences were greater among the girls than among the boys. Early restoration of the first permanent molar teeth did not indicate high filling increments in the incisors, canines or the smooth surfaces of any tooth.

CONCLUSION

Fissure caries and smooth surface caries are different entities. The present method can be of help as an additional tool to help the clinician identify "risk" patients, in that an early restoration in any first molar is a powerful indicator of a risk of restorations in the other first molar teeth and also the second molar teeth.

Timing of first restorations before, during, and after a preventive xylitol trial

An independent longitudinal retrospective analysis of the timing, number, and cost of tooth restorations was conducted for all subjects (n = 313) in the age cohort of a municipal health center, in which two consecutive field trials of up to 3 years on the caries-preventive effect of the use of xylitol chewing gum were conducted (Ylivieska study, 1982-85). A computer program calculated the post-eruptive timing of the first restorations on each permanent tooth surface, and survival analysis methods were applied before, during, and after the trials. The cost of restorations was then calculated. The total number of new restored surfaces was 4.0 per child in the xylitol group and 9.3 in the controls during the decade after onset of the trial. The number of restorations on the occlusal surfaces of the first molars leveled off at 40-50% in the xylitol group and at about 60-70% in the control group. Plateaus for the second molars were at 30-40% and 60-70%, respectively. The time lag for the first restorations was longer in the xylitol group for the proximal and other smooth surfaces. A marked difference in favor of the xylitol group was observed in the proximal surfaces of the upper incisors (for example, the mesial surface of the upper mesial incisor for girls: log-rank chi-square = 11.1, p < 0.001). The preventive effect was most pronounced in teeth that had erupted during the trial. This analysis indicated that participation of subjects in the xylitol chewing gum trials resulted in a significant reduction in the number of first restorations and hence in costs during the decade after the onset of gum use.

Effect of early or late eruption of permanent teeth on caries susceptibility

OBJECTIVES

The aim of this study was to analyse the possible effect of early or late eruption of permanent teeth on the placement of first restorations on the different surfaces. The oral health records, of a total of 486 children born in 1970 and 1971 living in three rural communities in Finland, were analysed.

METHODS

Caries susceptibility was determined indirectly by a new method. The study groups were defined as falling outside one standard deviation either side of the mean value for the timing of the eruption of first permanent molar teeth.

RESULTS

No statistically significant differences in restoration increments between the early and late eruption cohorts were found at the end of the study period. For the occlusal surfaces of the first molar teeth, the restoration placement curves plateaued at about 60-70%, while for the second molar teeth, the plateaus occurred at 50-60% for both study cohorts. In girls with 'late eruption', the height of the post-eruptive step (i.e. the number of teeth filled on the year of their eruption) was higher (50-100%) compared to boys and girls with 'early eruption'. The difference was statistically significant. For example, for the occlusal surface of D. 36, the 95% confidence interval for the difference between proportions was 12-53%.

CONCLUSION

No consistent effect of early or late eruption of permanent teeth was found on caries susceptibility measured post-eruptively by the placement rate of first restorations in a follow-up study of more than 10 years among Finnish children born in 1970-1971.

Timing of first restorations in permanent teeth: a new system for oral health determination

OBJECTIVES

A system of oral health determination in which times between eruption of teeth and first restorations because of caries is measured is applied in a retrospective analysis of oral health data relating to rural health centres in Finland.

METHOD

The retrospective analysis was carried out using data relating to three health centres in different parts of Finland. The times between eruption and the placement of the first restorations in subjects up to 18 years of age were investigated.

RESULTS

Between 10% and 25% of all permanent molar teeth were filled in the year of tooth emergence--the 'immediate posteruptive step'. A steadily increasing restoration placement rate--the 'ascending growth phase'--was observed after the 'posteruptive step'. The restoration rate was found to plateau 5-8 years after eruption--the 'retardation phase'.

CONCLUSIONS

Restoration increment curves with longitudinal measurements are believed to be a sensitive indication of oral health at both individual and population levels.

Timing of first fillings on different permanent tooth surfaces in Finnish schoolchildren

The timing of the placement of first fillings because of caries on different permanent tooth surfaces was determined at three health centers in Finland. The 927 subjects analyzed were born either in 1970-71 o4 in 1980-81. Basically, two different types of filling placement site were identified: 1) fissures and pits and 2) proximal and smooth surfaces. In some fissures and pits a 'post-eruptive'--that is, fillings placed in the year of emergence--was observed. This step had decreased markedly in the cohort born in 1980-81. The curves plateaued (retardation phase) at 50-60% for the occlusal surfaces in first molars for the children born in 1970-71 and at 20-30% for the younger cohort. The time without any filling varied from 1 to 7 years on smooth surfaces, and some surfaces remained totally filling-free. The filling placement curves followed the pattern of caries attack and can thus be used as an indicator of dental health.

Timing of eruption of permanent teeth: standard Finnish patient documents

Current standards for the eruption of teeth are constructed mostly on the basis of cross-sectional data. The aim here was to analyze the suitability of the standard patient documents created for health center dental care purposes for the collection of longitudinal data on tooth emergence. Copies of the oral health records of the 911 children born in 1970 and 1971 and in 1980 and 1981 living in three rural communities in Finland were re-examined and analyzed using a specially compiled computer program. The means and standard deviations are in line with previous results. The sex difference in emergence timing ranged from 0.1 to 1.0 years for the various teeth. The emergence of the teeth of the second phase of the mixed dentition was later in the children living in an endemic fluoride area, this difference being statistically greater for the boys than for the girls (95% Cl for differences between means was used to evaluate statistical significance). A secular trend in the eruption of permanent teeth was found between 1970 and 1980. Patient documents are shown to be suitable for the collection of longitudinal data on dental emergence.