Fluoride in plaque following use of dentifrices containing sodium monofluorophosphate.

Previous work showed that plaque fluoride increased with increasing NaF content of mouthwashes following daily use. The main aim of this study was to test whether a similar relationship was detectable after regular use of dentifrices containing amounts of sodium monofluorophosphate equivalent to 1000, 1500, and 2500 micrograms F/g. Plaque was collected from three groups, each consisting of approximately 80 children, who had each used one of the dentrifrices for one year. Plaque fluoride increased significantly with increasing Na2FPO3 content of the dentifrices. For the 1000-micrograms-F/g group, plaque fluoride also increased significantly with increasing frequency of dentifrice use, but did not correlate with amount of dentifrice applied per brushing. The inverse correlation observed between mean plaque fluoride concentrations and mean three-year caries increments suggests that oral fluoride measurements may prove valuable in estimating the likely anti-caries efficacy of fluoride-containing dental products.

Improved sensitivity in caries clinical trials by selection on the basis of baseline caries experience.

As caries prevalence in some countries declines, and panel sizes for discriminating anti-caries clinical trials inevitably increase, the need for participant pre-selection grows to avoid escalating cost and manpower problems. Hence, retrospective analyses of data were undertaken, from a 3-yr double-blind caries clinical trial where a linear fluoride dose-response had been obtained. As a result, it was demonstrated that the eruption status of permanent second molars, in 3005 participants aged 11-12 yr at outset, when coupled with their baseline clinical DMFT values, provided a sound basis for panellist size prediction without loss of sensitivity. Thus, had only those subjects with DMFT greater than 4, with at least three of their permanent second molars erupted been selected following clinical baseline examination, the same sensitivity would have been achieved with 52% fewer subjects. Furthermore, using these criteria, selection can be made on site, in real time, and a child informed whether its immediate participation in a trial is possible.

Comparison of fibre optic transillumination with clinical and radiographic caries diagnosis.

Fibre optic transillumination (FOTI) has been employed during the course of a 3-yr clinical dentifrice trial which initially involved 3003 children. At the initial examination, a subgroup of 813 13-yr-olds, and at the following annual visit, 2247 14-yr-olds, were examined using a 150 W lamp and 0.5 mm diameter probe. Routine clinical and radiographic examinations were performed separately. Compared to the clinical scores for anterior teeth, FOTI detected an additional 64% of interproximal lesions at the first visit while, for the larger number of children at the second visit, the increase in lesion detection level using FOTI was 37%. For the posterior teeth the comparable figure at the second examination was 92%. When FOTI data were compared to radiographic data for more than 52,000 posterior interproximal surfaces, FOTI could only detect 17% of radiographic Grade 2 lesions and 48% Grade 3 lesions. Thus any assumption that FOTI diagnoses may be a substitute for bitewing radiography appears premature.

Salivary levels of mutans streptococci, Lactobacillus, Candida, and Veillonella species in a group of Scottish adolescents.

Salivary levels of mutans streptococci, Lactobacillus, Candida, and Veillonella species were investigated on three occasions at annual intervals in a group of 372 Scottish adolescents. Counts of the micro-organisms studied were logarithmically distributed, with Candida spp. being isolated from approximately half the subjects. Counts of lactobacilli, mutans streptococci, and candida were significantly intercorrelated, while veillonella were associated consistently with mutans streptococci alone. Levels of each of the four micro-organisms were significantly correlated over the three examinations, with levels of the Candida spp. being the most stable over the period studied.

Caries prevalence and microbiological and salivary caries activity tests in Scottish adolescents.

Salivary and microbiological caries activity tests were investigated on three occasions in a group of 372 Scottish adolescents. Counts of lactobacilli, mutans streptococci, and candida were consistently and significantly associated with caries prevalence, as either DS or DMFS score, and buffering capacity was consistently inversely related to DMFS score. However, veillonella counts and salivary flow rate were not correlated with caries prevalence. Significant improvements in the associations were obtained when the results of more than one test were included using stepwise regression analysis. On an individual basis, at most, stepwise discriminant analysis identified the DMFS group correctly in 49% of all subjects, and the DS group in 47%.

Prediction of caries increment in Scottish adolescents.

Salivary, clinical, and microbiological factors were compared with subsequent 2-yr caries increment in a group of 372 Scottish adolescents. The caries increment was significantly correlated with previous caries experience, salivary buffering capacity and counts of lactobacilli, mutans streptococci and candida. Veillonella levels and salivary flow rate were not correlated with caries increment. Significant improvements in the predictions were obtained when the results of more than one test were included using stepwise regression analysis. On an individual basis, using stepwise discriminant analysis, the caries increment group (low, medium, or high) was identified correctly in 49% of all subjects, but this was reduced to 45% if previous caries experience was excluded from the analysis.

A 3-year oral health dose-response study of sodium monofluorophosphate dentifrices with and without zinc citrate: anti-caries results.

A 3-yr clinical trial has been conducted on 3000 12-yr-old children in Lanarkshire, Scotland, with the aim of investigating the effects on oral health of toothpastes containing both sodium monofluorophosphate and zinc citrate, the former being present at fluoride levels of 1000, 1500, and 2500 ppm F. No significant difference in caries increments was found between the group of children using toothpastes incorporating zinc citrate and their counterparts using zinc-free pastes. However, a significant anti-caries dose-response was demonstrated over the SMFP range used. This dose-response was evident for boys and girls and also for the various types of teeth and tooth surfaces.

The prevalence of clinically undetected occlusal dentine caries in Scottish adolescents.

During the third examination of a 3-year anti-caries dentifrice study, bitewing radiographs were read to detect occlusal, as well as approximal caries lesions in 2623 subjects aged 14-15 years. These analyses showed that 1.4% of 2107 upper molars and 7.2% of 2288 lower molars (P less than 0.001), previously scored as clinically 'sound', were carious at a radiographic Grade '3' score (dentinal involvement), and 0.2% had radiographic pulpal lesions. However, for teeth which had been deemed as having a 'suspicion' of caries clinically, but which a 0.6 mm blunted probe would not enter, 29.1% of lower molars had definite radiographic evidence of dentinal caries as compared to only 7.6% of upper molars (P less than 0.001), and a further 0.5% exhibited pulpal extension. In addition, 23.9% of lower premolars also showed dentinal involvement in this group. Overall, 12.1% of lower molars and 3.1% of upper molars showed definite radiographic evidence of occlusal caries in the absence of a firm clinical indication. Thus, the use of bitewing radiographs would appear to be a most helpful adjunct to clinical caries diagnosis, not only of approximal lesions, but also for the detection of early occlusal caries, in these days of generally available topical fluoride.

The prevalence of fissure sealants in Lanarkshire, Scotland. A 3-year study.

Fissure sealant presence was recorded at baseline and annually during a 3-year, double-blind clinical caries trial which involved 3005 children aged 12-13 years at outset. At baseline, initially, 2002 sealants were noted in 431 subjects (14.3%), a figure not dissimilar to that found for Scottish 12-year-olds in the UK National Survey completed in the same year. By the fourth examination, 400 (17.3%) children had 2209 surfaces sealed. After one year, 14%, and at 3 years, 26% of baseline sealants were missing. Overall, at the last examination, 25% of baseline unsealed surfaces were carious compared to 15% of those originally sealed (P less than 0.001), although for molars, the equivalent figures were 49% and 24% (P less than 0.001). Finally, analysis showed that at baseline, as few as 15% of sealants had been placed by general dental practitioners, and this low proportion was maintained throughout the study period. While sealant placement in the Scots' age group was low, nevertheless the prevalence recorded was greater, at least by a factor of three, than has been reported elsewhere in the UK.

Effect of oral care habits on caries in adolescents.

Data on toothbrushing habits were collected during a 3-year caries clinical trial of sodium monofluorophosphate toothpastes in Lanarkshire, Scotland, involving 3,005 schoolchildren of mean age 12.5 years at baseline. Stated normal brushing frequency and oral rinsing method after brushing were recorded. Half the panel indicated they rinsed their mouths after toothbrushing using a beaker. The proportion of the panel brushing once per day or more increased during the trial. Differences in oral habits were observed between the sexes, with 42% of girls and 52% of boys being non-beaker rinsers and 73% of girls, but only 44% of boys, brushing their teeth at least twice per day. Twice-a-day brushers had a consistently lower caries increment than less frequent brushers. This was also seen in the baseline prevalence data, but did not account for all incremental differences noted. Subjects using beakers had consistently higher increments than non-beaker rinsers. Again, this difference could not be explained by variations in baseline prevalence. Differences in the caries increment were also observed between boys and girls, these appearing to be linked both to the cumulative effect of male/female habit variations plus a difference in the baseline caries prevalence. A dose response to the three fluoride levels, i.e 1,000, 1,500, and 2,500 ppm F, was seen for the different habit combinations which again could not be explained by differences in the baseline caries prevalence.