Caries prevalence on the buccal surfaces of teeth in orthodontic patients was determined with QLF and visual examination immediately after removal of fixed appliances. The number of lesions found by QLF far outnumbered that found by visual examination, but the distribution pattern was similar. 97% of all subjects and on average 30% of the buccal surfaces in a person were affected. On average, in males 40% of surfaces and in females 22% showed white spots (p < 0.01). Caries prevalence was lower (p < 0.01) in incisors and cuspids than in molars and premolars. A positive correlation with caries prevalence was found for the bleeding scores 6 weeks after debonding and lactobacillus counts before debonding. Mutans streptococci counts, age, treatment duration, socioeconomic status and dietary habits showed no correlation with caries prevalence.

A dysbiotic state is believed to be a key factor in the onset of oral disease. Although oral diseases have been studied for decades, our understanding of oral health, the boundaries of a healthy oral ecosystem and ecological shift toward dysbiosis is still limited. Here, we present the ecobiological heterogeneity of the salivary ecosystem and relations between the salivary microbiome, salivary metabolome and host-related biochemical salivary parameters in 268 healthy adults after overnight fasting. Gender-specific differences in the microbiome and metabolome were observed and were associated with salivary pH and dietary protein intake. Our analysis grouped the individuals into five microbiome and four metabolome-based clusters that significantly related to biochemical parameters of saliva. Low salivary pH and high lysozyme activity were associated with high proportions of streptococcal phylotypes and increased membrane-lipid degradation products. Samples with high salivary pH displayed increased chitinase activity, higher abundance of Veillonella and Prevotella species and higher levels of amino acid fermentation products, suggesting proteolytic adaptation. An over-specialization toward either a proteolytic or a saccharolytic ecotype may indicate a shift toward a dysbiotic state. Their prognostic value and the degree to which these ecotypes are related to increased disease risk remains to be determined.

WHO data suggest that all over the world the prevalence of caries has declined at the end of the previous and in the first decade of the present century. This decline started wherever the use of effective fluoride toothpaste became commonplace. Even though the decline is considerable with a 90 % reduction in DMFT for 12-year-olds in Western Europe and the USA, caries still affects 60–90 % of the children throughout the world. In the high- and middle-income countries, the nature of caries has changed from a rapid progressing disease of childhood to a slowly progressing disease throughout adulthood and even old age. However, throughout the world, the circumstances for caries differ, e.g., low-income countries experience more caries with higher sugar consumption, while between high-income countries this correlation is reversed. In high-income countries, fluoride is widely used and preventive programs in dental offices are in place. These programs, if effective, may not be a realistic option in low-income countries. In order to reduce caries in the world even further, the use of effective and affordable fluoride toothpaste should be encouraged and enabled.

The aim of this study was to determine maximum attainable protection of enamel from erosion and erosion abrasion using a highly fluoridated gel with and without additional fluoride from toothpaste. Thirty-six bovine enamel specimens were subjected to six erosive attacks per day (1% citric acid with pH 2.3 for 30 s), while the rest of the day the specimens were in artificial saliva. There were four treatment groups (9 specimens in each group): fluoride-free toothpaste/saliva slurry twice daily (group T0), fluoride-containing toothpaste/saliva slurry twice daily using 1,250 ppm F toothpaste (group TF), fluoride-containing toothpaste/saliva slurry twice per day plus application of a highly fluoridated gel (12,500 ppm F) twice a day for 120 s (group 2F) and a group with gel application 8 times a day (group 8F). Additionally, half of each specimen in all groups was subjected to brushing abrasion during application of the toothpaste/saliva slurry. Brushing abrasion alone led to no observable enamel loss measured with profilometry. After 14 days of cycling of erosion without toothbrushing abrasion, high-fluoride gel application 2 or 8 times daily showed significantly less enamel loss (median 24/19 µm) than with toothpaste with or without fluoride (41/45 µm). After 14 days of cycling of erosion and toothbrushing abrasion, gel application 2 or 8 times daily (33/29 µm) showed significantly less enamel loss than toothpaste with or without fluoride (57/62 µm). We conclude that a highly fluoridated acidic gel is able to protect enamel from erosion and toothbrushing abrasion while fluoridated tooth paste provides little protection.

The inhibition of enamel demineralisation and the enhancement of remineralisation are positively but not linearly related to the concentration of fluoride, especially when high fluoride concentrations are used. The aim of this in situ experiment was to determine the maximum amount of enamel remineralisation that can be achieved with daily applications of very high concentrations of fluoride. For this purpose we compared the efficacy of a daily application of fluoridated topical gel (12,500 ppm F, partly as NaF, Olafluor and Dectafluor, pH 4.5) in combination with a fluoridated toothpaste (1,450 ppm F as NaF), with fluoridated toothpaste alone. Participants (n = 26, with partial dentures) were fitted with a demineralised enamel specimen (mean mineral loss of 1,674 vol%·µm) and were instructed to use one of the two fluoride treatments. After 4 weeks of treatment, the specimens were retrieved, a section was cut and analysed with microradiography. The remainder of each of the specimens was used for analysis of the ‘loosely bound’ and ‘bound’ fluoride. Fluoride was measured with gas-liquid chromatography. After 4 weeks in the mouth, the original lesion was reduced in size by 54% in the toothpaste + gel group (n = 14) and by 44% in the toothpaste-only group (n = 12), but the difference between the groups was not statistically significant. The mineral content profiles showed remineralisation of the lesions throughout the depth of the lesion. The enhancement of remineralisation by the high amounts of fluoride was most pronounced in the surface layer. For both the ‘loosely bound’ and ‘bound’ fluoride, a statistically significant increase in fluoride concentration could be found in the toothpaste + gel group. In the 4-week in situ period the use of high amounts of fluoride resulted in a maximum remineralisation rate. This is illustrated by an increase in remineralisation and higher fluoride concentrations in the toothpaste + gel group compared to the toothpaste-only group.

Objective To comparatively evaluate the effectiveness of three different methods involving end-users for detecting usability problems in an EHR: user testing, semi-structured interviews and surveys. Materials and methods Data were collected at two major urban dental schools from faculty, residents and dental students to assess the usability of a dental EHR for developing a treatment plan. These included user testing (N=32), semi-structured interviews (N=36), and surveys (N=35). Results The three methods together identified a total of 187 usability violations: 54% via user testing, 28% via the semi-structured interview and 18% from the survey method, with modest overlap. These usability problems were classified into 24 problem themes in 3 broad categories. User testing covered the broadest range of themes (83%), followed by the interview (63%) and survey (29%) methods. Discussion Multiple evaluation methods provide a comprehensive approach to identifying EHR usability challenges and specific problems. The three methods were found to be complementary, and thus each can provide unique insights for software enhancement. Interview and survey methods were found not to be sufficient by themselves, but when used in conjunction with the user testing method, they provided a comprehensive evaluation of the EHR. Conclusion We recommend using a multi-method approach when testing the usability of health information technology because it provides a more comprehensive picture of usability challenges.

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.

The results suggest that FFB is important for performance in a VLE and essential for satisfaction.