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.
Approximal surfaces are a focal point for caries prevention among adolescents in Sweden and the aims of this study were therefore to evaluate approximal caries incidence and caries progression among adolescents with and without a three-year school-based fluoride varnish programme in relation to approximal caries prevalence at baseline.
In all, 758 (89%) 13-year-olds completed the three-year randomised controlled trial. They all used fluoride toothpaste at home and had regular dental check-ups at the public dental clinics.
The mean approximal caries incidence for the adolescents who were caries free on these surfaces at baseline was 0.13 (SD 0.54) in the fluoride varnish group and 0.79 (1.93) in the control group. The corresponding values for those who had caries at baseline in these groups were 1.29 (2.21) and 2.62 (3.22) respectively. The latter two groups also had 0.34 (1.00) and 0.70 (1.13) approximal enamel lesions that progressed. All differences were statistically significant (p?0.001). Among those individuals who had approximal caries at baseline, double the number of early approximal enamel lesions in the control group progressed compared with the fluoride varnish group.
The school-based fluoride varnish programme inhibited new approximal lesions to a great extent and effectively kept approximal enamel lesions within the enamel among 13-16-year-olds. It is therefore recommended that such a programme is warranted when the approximal surfaces are still caries free in order to keep these surfaces free from caries and keep upcoming approximal enamel lesions within the enamel.
Cavitation of enamel lesions probably represents a significant step regarding further progression of the caries process. The primary objective of this study was to examine in adolescents the macroscopical appearance of approximal surfaces with radiographic lesions and relate this to the caries activity of the individual. A second objective was to establish the clinical feasibility of a modified technique for inspection of approximal contact surfaces. The material consisted of 46 enamel lesions selected on the basis of routine bite-wing radiographs of 140 patients aged 17-18 years, available from the Public Dental Service of Lillehammer, a non-fluoridated town. Lesions close to or approaching the AD junction were classified as D2 lesions, whereas those demonstrating a shadow not more than 1 mm into the dentine were designated D3 lesions. Based on recorded treatment during the last 3 years, patients were dichotomised as caries-active (CA) if they had more than 6 new lesions involving the dentine. The remainder with little or no activity were designated modestly active (MA). A small orthodontic rubber ring was placed around the contact point of the approximal surface of interest 1 day before an impression was taken. A separation of 0.5 mm facilitated cleansing and injection of low viscosity impression material (Xantopren(R) L, Blue, Bayer Dental). Discontinuity in the approximal enamel surface, determined by visual inspection of stone dyes, prepared from the impressions, was classified as cavitation. The results demonstrated that in MA patients D2 lesions seldom had cavities while in CA patients cavitation was usually found both in D2 and D3 lesions. The feasibility of the impression/inspection method seems established. It is easily performed and should be considered as a diagnostic tool in borderline cases.
In trying to make a comprehensive caries risk profile for an individual, one faces a situation that several factors need to be considered and weighted together. Summarising these factors could be a complex process and to facilitate the practical application, a computer-based risk assessment model for caries, the Cariogram, was developed. The Cariogram program operates basically in such a way that information on a number of factors are collected about the patient, transferred to 'scores' and these scores then entered into the program. According to its built-in algorithm, the program evaluates the data and presents the summarised result expressed as one figure, a pie-diagram, illustrating the 'Chance of avoiding cavities' in the future. This thesis deals with the evaluation of the Cariogram model and, as a first step, it was important to investigate if the program was in line with how colleagues, dental students and dental hygienists would evaluate a set of cases. The first two studies (Paper I and II) confirmed that the 'opinion' on the risk profile of the risk assessment program was in line with the opinions of the majority of the responders in these groups. In the third study (Paper III), the Cariogram's assessments were tested against the "reality" for the first time. The model was used to assess risk for caries among children and to evaluate the program by comparing the caries risk assessments of the risk model with the actual caries increment of the children over a two-year period. The hypothesis was that the Cariogram should be able to sort the children into caries risk groups according to the actual caries increment and the results confirmed the theory. It was also demonstrated that the Cariogram assessed caries increment more accurately than any included single factor model. Following the evaluation of the program on the children, the aim of the fourth study (Paper IV) was to evaluate the model for risk assessment in a group of elderly individuals. Comparing the caries risk assessment of the program with the actual caries increment over a five-year period showed that the program was able to arrange this group of elderly individuals into risk groups that reflected the actual caries incidence. The aim of the fifth study was to compare the risk profiles of the children with the risk profiles of the elderly. The evaluation of caries risk among the children showed that 3% was considered having very high caries risk, while 50% appeared in the low risk group. The corresponding values for the group of elderly individuals were 26% and 2%. Overall, the risk for caries, as assessed by the Cariogram, was twice as high for the elderly as for the children (V). The present thesis also tries to explore the concept of risk, the terminology and definitions related to risk, risk management and risk assessment in dentistry.
The development of dental caries from the age of 2.5 to 3.5 years was studied longitudinally in 692 children living in the southern suburbs of Stockholm. The parents answered a structured questionnaire concerning the family's social and immigrant background as well as the dietary habits, oral hygiene and fluoride exposure of their children. Furthermore, the occurrence of mutans streptococci and lactobacilli was determined in samples taken from the tongue of the children, and the buffer capacity of the saliva was measured. At baseline examination, 11.3% of the children exhibited dental caries. At follow-up, 1 year later, decayed and/or filled surfaces were registered in 36.7% of the subjects. The majority of the new lesions were located on the occlusal surfaces of the second molar. Ninety-two percent of the children with caries at baseline developed new carious lesions during the 1-year period, compared to 29% of the children who were caries-free at baseline (p
The caries increment (filled surfaces) from the ages 7 to 15 years were compared in children with three or fewer (low prevalence group) or eight or more filled surfaces (high prevalence group) at the age of 8. The children participated in a fortnightly fluoride mouthrinsing program (10 ml of 0.2% NaF). Following 8 years of dental treatment and caries prophylaxis, the caries increments were 11.4 (s.d. = 7.7, n = 23 subjects) and 17.1 (s.d. = 9.6, n = 39 subjects) surfaces, i.e. significantly different (t = 2.376). Significantly (t = 4.034) more fillings had been required in the high than in the low prevalence group (31.1 +/- 17.1 vs. 15.5 +/- 9.6). The "risk group" could be identified at the ages of 7 to 8 by high caries prevalence and high ratio fillings/caries increment. Social class and number of teeth accounted more for the initial caries prevalence than for the caries increment. Correlation analyses revealed a significant, but not strong (r = 0.50), association between caries prevalence at the age of 7 and increment of fillings.
The main purpose was to study various factors with respect to predicting dental caries. From a population of 442 employees at a shipyard, 68 patients with an average age of 56 yr were selected for the present investigation. They were examined once a year during a 2-yr period with respect to: 1) number of new caries lesions, and 2) a series of caries related factors, i.e., DMFS, oral hygiene status, dietary habits, numbers of Streptococcus mutans and lactobacilli in saliva, and secretion rate and buffer effect of saliva. The median values of all studied variables as found at the baseline examination were more favorable in the caries inactive (n = 30) than in the caries active group (n = 38), but only DMFS (P less than 0.001), dietary score (P less than 0.05), and number of S. mutans in saliva (P less than 0.05) differed significantly between the two groups. Number of S. mutans showed the highest sensitivity value, followed by dietary score. The main conclusion from this study is, however, that in spite of a relationship between caries activity and unfavorable values, especially for DMFS, dietary score, and number of S. mutans in saliva, it would have been difficult to predict the caries active patients on an individual level.
This paper considers the question of whether, by using the currently available measures for assessing caries risk, one can identify with sufficient accuracy the high caries-risk susceptible individuals who need individual protection to avoid having an unacceptably high number of new cavities. In addition, the outline of a typical caries prediction study is presented with an example, Finally, the accuracy of an actual caries prediction is compared with the accuracy of predicting the onset of acute myocardial infarction in order to point out the fact that the risk of any disease is difficult to assess accurately.