Caries incidence in adolescents with low caries prevalence after cessation of weekly fluoride rinsing.

The aim of this study was to determine whether cessation of weekly fluoride rinsing leads to an increase in caries incidence in a group of adolescents with low caries prevalence. Sixty randomly selected 12- to 14-year-olds were asked to stop rinsing at school (test group). After 3 years caries increment and caries progression were compared with an age- and sex-matched control group (n = 60), who continued to rinse weekly with a 0.2% sodium fluoride solution. All children in both groups had followed a school-based fluoride rinsing program from the age of 6 years. The mean (standard deviation) caries increment, including only open lesions, during the 3 years was 1.58 (1.73) in the test group and 1.48 (1.80) in the control group. The corresponding figures for incipient lesions were 3.13 (3.63) and 4.03 (4.23), respectively. The mean caries progression was 0.92 (1.34) in the test group and 0.72 (1.03) in the control group. None of these differences were statistically significant. Thus, this study showed that a cessation of weekly fluoride rinsing did not lead to an increase of caries incidence in a group of adolescents with low caries prevalence.

Disease activity and need for dental care in a capitation plan based on risk assessment.

This article describes a capitation model of care which would stimulate both dentists and patients to apply existing preventive knowledge.

Differences in caries recording with and without bitewing radiographs. A study on 5-year old children in the County of Bohuslän, Sweden.

In Sweden, when caries prevalence was much higher, bitewing radiographs (bwg's) were taken on all school children at their annual examination. It has been argued that bwg's should also be taken on 4- to 6-year-olds, with approximal surfaces in the molar area in contact (Stecksén-Blicks & Wahlin 1983). However, discussion about radiation-risk in combination with low caries prevalence seem to have made Swedish dentists reluctant to take radiographs on pre-school children. The aim of this study was to find out if there was a difference in caries recording when information from bwg's was added to that from clinical examination. Therefore 180 5-year-old children were randomly selected to constitute a test group examined both by the dentists who see the patients at the annual examination and do not use bwg's and by two of the authors, who had access to bwg's. No statistically significant difference in carries prevalence was noted from the registrations made by the clinicians and the authors when bwg's were not used (x = 1.8 versus 2.0). When the authors had access to bwg's they considered 1.8 more surfaces to be carious compared to when bwg's were not used (x = 3.8 versus 2.0). Of these, 1.0 surfaces were open lesions and 0.8 were incipient lesions. The difference was statistically significant (p < 0.001) as tested by paired t-test. Extreme differences were noted in single cases. It was concluded that clinical examination only, underestimates the correct caries status.

Is caries prevalence underestimated in today's caries examination? A study on 16-year-old children in the county of Bohuslän, Sweden.

When caries prevalence was higher than today incipient lesions constituted 70% of carious lesions. Incipient lesions were often neglected in caries recordings and hence the true caries prevalence was underestimated. Moreover, it has been shown that there were evident differences in caries status between different areas in the same county though the preventive measures were supposed to be the same (Moberg Sköld et al 1984). To find out if the conditions were the same when caries prevalence has decreased a total number of 240 16-year-old children were examined concerning caries in 1987 and 1990. The results showed that the caries prevalence was still underestimated. Incipient lesions constituted 80% of the total number of carious lesions which was approximately the same as when caries prevalence was higher. The difference in caries status within the country had decreased compared with the study in 1984 (Moberg Sköld et al 1984).

Dental caries, mutans streptococci, lactobacilli, and saliva secretion rate in adults.

In 718 Swedish patients, equally divided into four age groups (19-25, 26-45, 46-60, greater than 60 yr), salivary levels of mutans streptococci and lactobacilli, saliva secretion rate, and DMFS were registered. No significant differences were found between the various age groups either in salivary factors or in caries (D). Number of missing (M) and filled (F) surfaces increased with age. Prevalence of root caries, which increased with age, was significantly correlated to number of exposed root surfaces independent of age. Of the total study group, 50% had greater than or equal to 10(6) mutans streptococci and 40% had greater than or equal to 10(5) lactobacilli per mL saliva. Three percent had a saliva secretion rate of less than or equal to 0.5 mL/min. Correlation analyses showed that both mutans streptococci and lactobacilli significantly correlated to the caries prevalence but the r-value never exceeded 0.34.

Prediction of caries activity in children with today's low caries incidence.

One hundred 14-yr-old children were observed over 1 yr to find out if caries incidence and caries progression could be predicted in a low prevalence child population by means of well-known caries related factors. The mean caries incidence was low (0.45, SD 0.70) but, on the other hand, 32% of the children developed at least one new lesion during the test period. In only eight out of 35 children progressing lesions were demonstrated. Independent variables at baseline examination were caries prevalence, sucrose intake, fluoride exposure, oral hygiene, saliva secretion rate, and salivary concentrations of mutans streptococci and lactobacilli. A weak but statistically significant correlation was demonstrated between caries incidence and caries prevalence. No other significant correlations were shown. It was concluded that caries activity could not be predicted in this population. Low disease prevalence was a major reason for the weak correlations.

Microbial flora associated with presence of root surface caries in periodontally treated patients.

Examination of saliva and dental plaque was carried out in 35 adults who had been treated for periodontal disease 3 yr earlier. Plaque samples were collected from approximal and buccal sound and carious root surfaces. The samples were analyzed for the presence and proportions of members of Streptococcus, Lactobacillus and Actinomyces. The results showed a low prevalence of root surface caries and a low level of salivary mutans streptococci and lactobacilli. From subjects with root caries there was a not statistically significant tendency to higher proportional levels of mutans streptococci in plaque from carious root surfaces than from caries-free surfaces. An inverse significant relationship between noncarious and carious root surfaces was noted for S. sanguis. The population of A. viscosus and A. naeslundii was similar in plaque samples from sound and carious sites but showed elevated levels in the subjects with five or more new root surface lesions.

Differences in caries status and caries recording within and between two counties in Sweden.

One-hundred and seventy-six randomly selected 16-year-old children from six clinics in two neighbouring counties were examined by the dentists who see the patients every year, as well as by two calibrated examiners (two of the authors). Compared to the dentists, working in the dental clinics, the authors consistently noted a higher total caries score (DMFS + incipient lesions). The differences were statistically significant in four of the six clinics and most pronounced on incipient lesions. Furthermore, there was a significant difference in caries prevalence between the two counties. Possible explanations for the difference are resources available and efforts put into preventive dentistry.

Caries status and microbial conditions in children in 1973 and 1984.

In 1973 all 9-12-yr-old children in a county in Sweden were examined with regard to caries prevalence, salivary Streptococcus mutans and lactobacilli. Eleven years later the same parameters were analyzed in 250 randomly selected children of the same age and from the same county. Both the number of cariogenic microorganisms and the caries prevalence were significantly lower in 1984 than in 1973 (P less than 0.001). The lower number of S. mutans and lactobacilli could be due to several factors and is probably one of the reasons for the low caries prevalence in the children in the present study.

Comparison of effect of SnF2 and NaF mouthrinses on caries incidence, salivary S. mutans and gingivitis in high caries prevalent adults.

The effect of SnF2 and NaF mouthrinses were compared in subjects initially selected because of their high caries prevalence and high levels of salivary S. mutans. Subjects rinsed twice a day with either SnF2 or NaF (200 ppm F-). Subjects in both groups continued to be caries active during the course of the study. However, at the first year examination subjects rinsing with SnF2 had less S. mutans/ml saliva, a lower caries incidence and less gingivitis. After 2 yr the S. mutans levels in the SnF2 rinsing group remained significantly less. Both caries incidence and gingivitis were lower in the SnF2 group after 2 yr but the difference was not significant.

Long-term effect of intensive caries prophylaxis.

The purpose of the present study was to examine the long-term effect of intensive caries prophylaxis. A preventive program mainly based on professional toothcleaning was demonstrated to be highly effective against caries incidence over a 2-yr period. Five years after the termination of the test period 519 subjects, 17-21 yr of age, were reexamined. The results showed that 1) the smooth surface caries prevalence was very low, 2) a high number of the carious lesions became arrested with time, 3) a long-term effect seemed to be obtained in subjects at a high caries risk, and 4) salivary S. mutans and lactobacilli could be used for caries prediction over a 7-yr period.

Microbiologic effects of SnF2 and NaF mouthrinses in subjects with high caries activity: results after one year.

Twenty-two adults, considered to have high caries activity, rinsed for one yr with either SnF2 or acidulated NaF mouthrinses. Total colony-forming units and numbers of S. mutans and lactobacilli were estimated from saliva samples. Large reductions were found in the number of recoverable S. mutans in subjects rinsing with SnF2 but not in the NaF group.

Economic aspects of a caries preventive program.

Cost-benefit and cost-effectiveness analyses (CBA and CEA) have been done on a preventive program. The program included professional toothcleaning, dietary and oral hygiene instruction, topical fluoride application and sealing of pits and fissures in 9--12-year-old children over 2 years. All measures were delivered by a specially trained dental nurse. In spite of a marked reduction in caries activity both CBA and CEA indicated that the preventive program was highly uneconomic compared to traditional dental care (3.73/1). However, when comparing the cost per completely treated child and year in the trial clinic continuing to use the preventive measures described, with that in dental clinics with no special preventive programs the cost seemed to be lower in the trial clinic now markedly interested in prophylaxis.

A comparison between different methods for prediction of caries activity.

The aim of the study was to find out if any of the following factors, alone or in combination, could be used for prediction of caries activity: salivary S. mutans, salivary lactobacilli, buffer capacity, saliva secretion rate, salivary pH, the amount of plaque and the caries frequency. The patient material consisted of 300 children between 9 and 12 years old. The increment of caries after 1 and 2 years was compared with all the above factors registered at baseline. Only the factors caries frequency and S. mutans showed a significant correlation to caries activity. In one of the tests the lactobacillus count approached significance. The combination of high numbers of incipient smooth surface lesions, S. mutans and lactobacilli gave a mean value of caries activity almost three times that of the whole group (8.4 versus 3.1).

Microbial and salivary conditions in 9- to 12-year-old children.

The prevalence of S. mutans and lactobacilli, the salivary secretion rate, and salivary pH and buffer capacity were examined in 655 children 9-12 years old. Some of these factors were correlated with the frequency of caries. Positive correlations were observed between for example S. mutans and lactobacilli, between S. mutans and incipient smooth surface caries, and between lactobacilli and open carious lesion. A high proportion of the children showed large numbers of S. mutans and lactobacilli.