Caries Research

Mukai, Y.; Lagerweij, M.D.; ten Cate, J.M.

doi: 10.1159/000047469pmid: 11641566

A root dentin single–section model was developed to compare the efficacy of different fluoride treatments on the remineralization of lesions. Shallow (∼170 µm) and deep (∼400 µm) lesions were produced in acetic acid buffer solutions (pH 5.0) with 0.1– and 0.5–ppm fluoride for 3 days and 2 weeks, respectively. Next, the sections were pH–cycled for 4 weeks. Following the pH cycling, all sections were first remineralized for 5 weeks, then subjected to 10 days of demineralization. The treatments were (1) no treatment (control), (2) daily 1,450–ppm NaF toothpaste, (3) weekly 4,000–ppm fluoride solution, (4) a combination of treatments 2 and 3. In the shallow lesions, the 4,000–ppm fluoride solution and the combination treatment enhanced mineral deposition at the lesion front, producing a second, slightly hyperremineralized layer. Similarly, in the deep lesions a second remineralized layer was detected. In all lesions, the fluoride solution treatment showed significantly more remineralization compared to the control and the toothpaste treatment (p<0.05), most of which was formed during the pH cycling. In the demineralization period, the control showed significantly higher mineral loss than all other treatments. These results indicate that a 4,000–ppm fluoride solution might be effective for remineralization of root dentin lesions even over 400 µm depth.

Ganss, C.; Klimek, J.; Schäffer, U.; Spall, T.

doi: 10.1159/000047470pmid: 11641567

The aim of the present study was to evaluate the effect of fluoride on the progression of erosive demineralisation in human enamel and dentine using a cyclic de– and remineralisation model in vitro. The mineral content expressed in micrometres was determined daily by longitudinal microradiography (LMR) and presented as cumulative mineral loss over 5 days. For erosive demineralisation, all samples were immersed in 0.05 M citric acid (pH 2.3) for 6×10 min/day and stored in a remineralisation solution. Fluoridation measures were performed as follows: group 1: control, no fluoridation; group 2: toothpaste fluoridation 3×5 min/daily (NaF, 0.15% F^–); group 3: toothpaste fluoridation as group 2 and additionally application of a fluoride mouthrinse (Olaflur/SnF₂, 0.025%F^–) 3×5 min/daily and on days 1 and 3 gel fluoridation (Olaflur/NaF; 1.25% F^–) for 1×5 min. After the first experimental day, no significant differences were found between the groups. However, after 5 days the erosive mineral loss values for enamel were 147.5±18.7 µm in the control group, 128.1±15.0 µm in group 2 (p≤0.05) and 116.1±12.4 µm in group 3 (p≤0.001). In dentine, the respective values were 136.7±16.4, 111.8±26.9 (p≤0.001) and 60.3±17.8 (p≤0.001). The intensive fluoridation significantly reduced erosion progression in enamel but had a more pronounced effect on dentine. The results suggest that subjects with erosive lesions should use an intensive fluoridation measure.

Davis, B.A.; Raubertas, R.F.; Pearson, S.K.; Bowen, W.H.

doi: 10.1159/000047471pmid: 11641568

The decline in prevalence of dental caries in some segments of the population has been attributed mainly to extensive exposure to fluoride. Over the past decades, the use of fluoridated products has increased. During the same period, the consumption of food preservatives such as benzoates and sorbates has also increased substantially. Benzoates, in vitro, possess antibacterial properties similar to those of fluoride and in combination with fluoride could affect caries development. In the present study we explored the effects of sodium benzoate and fluoride in combination and alone on dental caries in our animal model. The results showed a combination of benzoate and fluoride reduced caries activity more effectively in rodents fed a cariogenic diet ad libitum than fluoride alone (p = 0.038).

Hata, S.; Mayanagi, H.

doi: 10.1159/000047472pmid: 11641569

The cariogenic potential of lactosylfructoside [O–β–D–galactopyranosyl–(1→4)–O–α–D–glucopyranosyl–(1↔2)–β–D–fructofuranoside] was estimated by experiments on oral streptococci in vitro and human dental plaque in situ. Lactosylfructoside was unable to support growth of the strains of Streptococcus mutans and S. sobrinus used in this study. However, it was able to support growth of strains of S. sanguis, S. mitis and S. oralis. Acid was produced rapidly by cell suspensions of S. oralis ATCC 10557 incubated with lactosylfructoside. Application of 5% w/v solution decreased the pH of human dental plaque. The minimum pH value was below 5.3. The results suggest that lactosylfructoside is as acidogenic as lactose and could be cariogenic if it is consumed frequently and retained for a long period in the mouth.

Dawes, C.; Dibdin, G.H.

doi: 10.1159/000047473pmid: 11641570

The objectives were to: (1) determine the salivary concentrations of urea during 20 min chewing of a sugar–free gum containing 30 mg of urea; (2) measure the degree to which this urea would diffuse into a gel–stabilized plaque; (3) study the effect of the urea on the fall and subsequent rise in pH (Stephan curve) on exposure to 10% sucrose for 1 min; (4) model the measurements 2 and 3 mathematically. In point 1, the salivary urea concentration of the 12 subjects peaked at 47 mmol/l in the first 2 min of gum chewing, falling within 15 min to the unstimulated salivary concentration of 3.4 mmol/l. Recovery of urea from the saliva averaged 81.5%. ‘Plaques’ of 1% agarose or 67% dead bacteria in agarose accumulated urea from the saliva roughly as expected, whereas those plaques containing 8% live and 59% dead Streptococcus vestibularis showed negligible accumulation. Computer modelling showed this difference to be due to urease of live bacteria breaking down the urea as rapidly as it entered the plaque. Simulation of the effect of gum chewing subsequent to initiation of a Stephan curve in the latter type of plaque showed a rapid rise in pH but then a fall again on return to unstimulated conditions. This fall had not been seen in previous studies, with Streptococcus oralis, nor was it predicted by the computer modelling. Neither experimental simulation nor computer modelling suggested that chewing urea–containing gum before exposure to sucrose would have any effect on a subsequent Stephan curve. Thus chewing gum is only likely to inhibit caries when it is chewed after consumption of fermentable carbohydrate, rather than before.

Nair, M.K.; Nair, U.P.

doi: 10.1159/000047474pmid: 11641571

This study compared the diagnostic efficacy of Kodak Ektaspeed Plus film, Kodak Insight film, a newly introduced E/F–speed film, and Schick CMOS–APS digital sensor, with respect to caries detection in 92 proximal surfaces of extracted unrestored teeth, 51 of which were carious. Ground truth was evaluated histologically and the lesions classified as enamel or dentinal. Eight observers read the radiographs using a five–point confidence rating scale to record their diagnoses. Analyses using receiver operating characteristic curves revealed the areas under each curve that indicated the diagnostic accuracy (Ektaspeed Plus – 0.760, Insight – 0.778 and CMOS–APS sensor – 0.732). ANOVA revealed significant differences with respect to caries depth (p<0.031) and observers (p<0.0001). Weighted kappa analyses indicated moderate to substantial inter– and intra–observer agreement (0.42 and 0.66, respectively). The results suggest that none of the imaging modalities evaluated in this study differed in their diagnostic capabilities with respect to proximal decay detection and that the Insight film which was used with 20% less radiation exposure than Ektaspeed Plus film was as good as the other two sensors for this purpose.

Hausen, H.; Kärkkäinen, S.; Seppä, L.

doi: 10.1159/000047475pmid: 11641572

Collecting data for dental caries studies is costly. In countries where uniform patient records are available for virtually the whole population, it is tempting to use them as a data source. Our aim was to compare data collected from patient records to those obtained by trained examiners. In 1992 and 1995, dentists who were specially trained and calibrated examined random samples of 12– and 15–year–olds living in two towns in Finland. The dental record of each child was obtained from public dental clinics, the dental status was entered into a computer file, and the DMFS value was calculated. Data were available for 824 children. In the two data sets, 1.3% of the tooth surfaces were recorded differently (DMF vs. sound) with the related ĸ value being 0.70. In two thirds of the discrepancies, the reason was that a filling was marked in only one of them, which confirms the known difficulty in discerning a white filling. For 48% of the subjects, the DMFS values calculated from the two sets of data were equal. The difference was 1 and 2 surfaces for 28 and 11%, respectively. Public health dentists had almost equally often registered more and less DMF surfaces compared to trained examiners. The results suggest that data collected from public health records are not decisively inferior to those obtained from examinations by trained examiners. In large enough settings, data obtained from patient records could possibly be used as a replacement for separate surveys.

Gilbert, G.H.; Duncan, R.P.; Dolan, T.A.; Foerster, U.

doi: 10.1159/000047476pmid: 11641573

Objectives: (1) Describe for a diverse sample the 24–month incidence of root caries, and (2) test its association with a broad range of clinical, behavioral, financial, and sociodemographic factors. Methods: The Florida Dental Care Study was a cohort study of randomly selected subjects who had at least 1 tooth and were 45 years or older at baseline. In–person interviews and clinical examinations were conducted at baseline and 24 months, with 6–monthly telephone interviews between those times; 723 subjects participated for both examinations. A multinomial logistic regression was done to predict whether the subject was in one of four mutually exclusive groups [new root decay only (NDO); new root filling(s) only (NFO); both new decay and new filling(s) (BOTH), or had neither (NONE)]. Results: Thirty–six percent of subjects had at least 1 new root decayed and/or filled surface (DFS); 17% were in the NDO group, 14% in the NFO group, and 5% in the BOTH group. When limited to participants who had a nonzero increment, the mean (SD) DFS was 2.7 (2.9). Baseline clinical condition (presence of root decay, root filling(s), coronal decay, noncarious root defects, number of teeth present, percent of teeth with at least 4 mm of attachment loss) was predictive of moving from the NONE group into the NDO, NFO, or BOTH groups. The addition of behavioral, financial, and sociodemographic factors improved model fit. For example, regular dental attenders were significantly more likely to move from the NONE group into the NFO group, but regular attendance was not associated with a lower probability of moving from the NONE group into the NDO or BOTH groups. Conclusions: Root caries is a substantive dental health problem in this diverse sample of adults. These analyses demonstrate the utility of disaggregating caries incidence into four mutually exclusive groups for predictive models.

Quiñonez, R.B.; Keels, M.A.; Vann Jr., W.F.; McIver, F.T.; Heller, K.; Whitt, J.K.

doi: 10.1159/000047477pmid: 11641574

The influences that link social factors and caries development are not well understood, although mediation by stress has been suggested. The association between caregiver stress and early childhood caries (ECC), in particular, remains unclear. The purpose of this study was to examine the relationships between parenting stress and ECC while controlling for behavioral and biological factors in a high–risk population. One hundred and fifty healthy children aged 18–36 months were examined in a cross–sectional study design. Parental interviews were conducted to obtain demographic, oral health behavior and parenting stress data. Clinical data included parent and child bacterial measures, fingernail fluoride analyses, caries prevalence and presence of child enamel hypoplasia. Bivariate analyses revealed that parenting stress predicted caries. Multivariate analyses demonstrated that a combination of psychosocial, behavioral, temporal and biological variables predicted ECC outcomes. Total parenting stress did not contribute independently to the best prediction model. Our findings suggest the need for the development of a multidimensional stress model that considers the parent–child dyad to elucidate further the link between psychosocial factors and ECC.

Nadanovsky, P.; Cohen Carneiro, F.; Souza de Mello, F.

doi: 10.1159/000047478pmid: 11641575

The aim of this study was to evaluate the efficacy, comfort and efficiency of removing dentin caries using only hand instruments. The Carisolv™ system for caries removal consisting of a solvent gel and a set of specially designed hand instruments (chemo–mechanical) was compared to the use of conventional spoon excavators (mechanical). This was a clinical randomised controlled trial where the two techniques were compared in the same individual. The outcome variables were: complete caries removal; pain during caries removal; anaesthesia requested by the patient during caries removal; time taken to remove caries. Sixty–six individuals, each with a pair of similar cavities in permanent teeth were selected. After caries removal, a ‘blinded’ evaluator assessed the clinical status of the cavity, with the use of a probe. The times for caries removal of the chemo–mechanical and mechanical methods were respectively: 9.2±3.8 and 8.6±3.8 min (p>0.05). There were 4 cavities arguably presenting signs of caries after cavity preparation in the 66 cavities treated with the mechanical method and 7 in the 66 chemo–mechanical cavities (p>0,05). Some pain/discomfort was reported by 21 (32%) participants when the chemo–mechanical method was used, compared with 43 (65%) when the mechanical method was used (p<0.05). During the chemo–mechanical and the mechanical treatment, 2 (3%) and 5 (8%) patients, respectively, requested local anaesthesia (p>0.05). The chemo–mechanical method appeared to be more comfortable for most patients.