[Dental health in German and Turkish school children--a 10-year comparison]. / Zahngesundheit deutscher und türkischer Schüler--Ein 10-Jahresvergleich.

The purpose of this cross-sectional study was to assess the changes in dental health in 12- and 15-year-old Turkish immigrants and German students who were included in a school-based caries-preventive programme for ten years (1993-2003). In 1993 352 and 402 12- and 15-year-olds and in 2003 352 and 402 12- and 15-year-olds were investigated, respectively. 23.6% of the 12-year-olds and 21.5% of the 15-year-olds were of Turkish origin. The clinical examination was performed with support of artificial light at school. Caries was diagnosed according to the WHO standard using the DMFT Index for permanent dentition. Within the ten-year period the highest increment of caries-free dentitions was found in 12- and 15-year old Germans attending grammar schools with 41,5% and 27% and secondary modern schools with 22,3% and 17%, respectively. The proportion of caries-free Turkish students attending secondary modern schools, only increased imperceptible in both age groups (1.2%). A significant caries decline of 1.5 DMFT was observed in 12-year old Germans at grammar schools, only. In 15-year olds caries declined in German students at secondary modern schools (2.5 DMFT), and at Grammar schools (2.2 DMFT), significantly, however caries experience in Turkish students remained nearly unchanged (0.3 DMFT). A strong polarisation of dental caries was found in 2003. Among the 12-year-olds 23% of those at secondary modern school accumulated 70% of the total caries experience (>3 DMFT) and at grammar school 9% of students accumulated 76% of the whole amount of caries (>1 DMFT). Among the 15-year-olds 73% of the total caries experience (>3 DMFT) was concentrated in 32% of the students at secondary modern schools, while 25% of the students at grammar schools exhibited 84% of the whole amount of caries (>1 DMFT). Intended concepts in caries prevention in the future should aim to improve dental health especially in Turkish students at secondary modern schools while taking social inequality of this risk group into account.

An in vitro comparison between two methods of electrical resistance measurement for occlusal caries detection.

Because of different measurement techniques and the easier design of the CRM prototype, this in vitro study aimed to compare the diagnostic performance and reproducibility of two electrical methods (Electronic Caries Monitor III, ECM and Cariometer 800, CRM) for occlusal caries detection, and to evaluate the effect of staining/discoloration of fissures on diagnostic performance. Hundred and seventeen third molars with no apparent occlusal cavitation were selected. Six examiners inspected all specimens independently, using the CRM, and a subgroup of 4 using the ECM. Histological validation using a stereomicroscope was performed after hemisectioning. Intra- and interexaminer reproducibility was assessed by Lin's concordance correlation coefficient (CCC) and Bland and Altman analysis. Diagnostic performance parameters included sensitivity (SE), specificity (SP) and area under the ROC curve (Az). The CCC yielded an intra- and interexaminer reproducibility of 0.69/0.62 (ECM) and of 0.79/0.74 (CRM). The mean intra- and interexaminer 95% range of measurements (range between Bland and Altman limits of agreement) given in percentages of the instrument reading were 67%/65% for the ECM and 28%/33% for the CRM. Az at the D3-4 level was 0.74 (ECM) and 0.78 (CRM). The CRM showed at least equivalent diagnostic performance to the ECM. However, improvement is still desirable. Diagnostic performance appeared to be enhanced in discolored lesions; however, this may be related to sample lesion distribution characteristics.

Comparison of the efficacies of disinfectants to control microbial contamination in dental unit water systems in general dental practices across the European Union.

Water delivered by dental unit water systems (DUWS) in general dental practices can harbor high numbers of bacteria, including opportunistic pathogens. Biofilms on tubing within DUWS provide a reservoir for microorganisms and should be controlled. This study compared disinfection products for their ability to meet the American Dental Association's guideline of <200 CFU x ml(-1) for DUWS water. Alpron, BioBlue, Dentosept, Oxygenal, Sanosil, Sterilex Ultra, and Ster4Spray were tested in DUWS (n = 134) in Denmark, Germany, Greece, Ireland, The Netherlands, Spain, and the United Kingdom. Weekly water samples were tested for total viable counts (TVCs) on yeast extract agar, and, where possible, the effects of products on established biofilm (TVCs) were measured. A 4- to 5-week baseline measurement period was followed by 6 to 8 weeks of disinfection (intermittent or continuous product application). DUWS water TVCs before disinfection ranged from 0 to 5.41 log CFU x ml(-1). Disinfectants achieved reductions in the median water TVC ranging from 0.69 (Ster4Spray) to 3.11 (Dentosept) log CFU x ml(-1), although occasional high values (up to 4.88 log CFU x ml(-1)) occurred with all products. Before treatment, 64% of all baseline samples exceeded American Dental Association guidelines, compared to only 17% following commencement of treatment; where tested, biofilm TVCs were reduced to below detectable levels. The antimicrobial efficacies of products varied (e.g., 91% of water samples from DUWS treated with Dentosept or Oxygenal met American Dental Association guidelines, compared to 60% of those treated with Ster4Spray). Overall, the continuously applied products performed better than those applied intermittently. The most effective products were Dentosept and Oxygenal, although Dentosept gave the most consistent and sustained antimicrobial effect over time.

Does irradiation affect the protein composition of saliva?

The purpose of this study was to compare the relative amount of low molecular weight salivary proteins in patients with head and neck tumours treated with radiotherapy and healthy subjects. Reverse-phase high-pressure liquid chromatography was used for protein separation. Nine protein fractions (including acidic and basic proline-rich proteins (PRPs), cystatins, histatins and statherin) were identified in saliva from irradiated patients as well as healthy subjects. However, compared with non-irradiated healthy subjects, the fraction of acidic PRPs was significantly reduced in irradiated patients. These data indicate an alteration of the relative amount of low molecular weight salivary proteins in irradiated patients besides the reduction of salivary flow.

Microbiological evaluation of dental unit water systems in general dental practice in Europe.

A range of opportunistic pathogens have been associated with dental unit water systems (DUWS), particularly in the biofilms that can line the tubing. This study therefore aimed to assess the microbiology of DUWS and biofilms in general dental practices across seven European countries, including the United Kingdom (UK), Ireland (IRL), Greece (GR), Spain (ES), Germany (D), Denmark (DK) and the Netherlands (NL). Water supplied by 51% of 237 dental unit water lines exceeded current American Dental Association recommendations of < or = 200 colony-forming units (CFU) ml(-1). Microbiological loading of the source waters was between 0 (Denmark, the Netherlands and Spain) and 4.67 (IRL) log CFU ml(-1); water line samples from the DUWS ranged from 1.52 (ES) to 2.79 (GR) log CFU ml(-1); and biofilm counts ranged from 1.49 (GR) to 3.22 (DK) log CFU.cm(-2). Opportunistic pathogens such as legionellae (DK and ES), including Legionella pneumophila SG1 (DK and GR), and Mycobacterium spp. (DK, NL, GR, D and ES) were recovered occasionally. Presumptive oral streptococci (ES and NL), oral anaerobes (GR), Candida spp. (UK, NL and ES) and blood (GR and IRL) were detected at relatively low frequencies, but their presence indicated a failure of the 3-in-1 antiretraction valve, leading to back siphonage of oral fluids into the water and biofilm phase. These findings confirm that a substantial proportion of DUWS have high levels of microbial contamination, irrespective of country, type of equipment and source water. The study emphasizes the need for effective mechanisms to reduce the microbial burden within DUWS, and highlights the risk of occupational exposure and cross-infection in general dental practice.

Comparison of different DIAGNOdent cut-off limits for in vivo detection of occlusal caries.

This study tested recently recommended cut-off limits for the laser fluorescence based device DIAGNOdent (KaVo) for detection of occlusal caries. Two hundred and forty-eight permanent molars from 94 patients (mean age 19.2 years) of a general dental practice were included. After professional tooth cleaning, the teeth were examined visually and by the laser fluorescence method. The extent of occlusal lesions (gold standard) was determined after minimal operative intervention. Upon fissure opening, 24 teeth had enamel caries and 224 teeth revealed dentin caries, of which 58 and 166, respectively, were up to or beyond half the dentin. The optimal cut-off limits based on the highest kappa-values (0.51 and 0.54) were > 18 for superficial dentinal caries (D3) and > 37 for deep dentinal caries (D4). The comparison with DIAGNOdent cut-offs given by the manufacturer (n = 4) and those based on clinical trials with in vivo validation (n = 4) and in vitro studies with histological validation (n = 3) revealed a considerable variation in performance. Recommended cut-offs between 17 and 21 for superficial dentin lesions were in the same order of magnitude (0.48-0.51). On the D4 level, only the manufacturer's cut-off of > 34 achieved the best performance (0.51). According to the highest kappa-values and the area under the ROC curves (D3: A(z) = 0.903; D4: A(z) = 0.830), the agreement between the extent of validated caries and laser fluorescence value is still unsatisfactory.

Peroxidase reaction as a parameter for discrimination of Streptococcus mutans and Streptococcus sobrinus.

425 strains of mutans streptococci and 12 reference strains were investigated by membrane fatty acid spectra (MFAS) and peroxidase reaction (PR) after aerobic and anaerobic incubation. 423 strains were identified as Streptococcus mutans. The remaining 2 strains were identified as Streptococcus sobrinus. The PR of 29 strains was doubtful; immediately after anaerobic incubation a negative PR changed into a slightly positive PR. To test the diagnostic value of PR the strains were additionally investigated by means of species-specific polymerase chain reactions (PCR). The species-specific PCRs were developed on the basis of the respective genes of 16S rRNA of the pathogens S. mutans and S. sobrinus. Specificity and sensitivity were tested on reference strains (n = 17) and negative control strains (n = 39). The results of this investigation showed that an anaerobic incubation regime could lead to false-positive (S. mutans) or false-negative (S. sobrinus) PR. The 425 MS strains were classified as either S. mutans (n = 420) or S. sobrinus (n = 5). The findings on the reference strains required a reclassification of S. mutans V 100 into S. sobrinus V 100. Summarising, it is possible now to differentiate strains of mutans streptococci by MFAS and PR after aerobic incubation.

Differences in acidogenicity of S. sobrinus and S. rattus are linked to the catalytic efficiency of the glycolytic key enzyme phosphofructokinase.

This contribution describes the biochemical properties of two catalytically different phosphofructokinases (PFKs) purified from Streptococcus rattus LB 2 (PFK-rat) and Streptococcus sobrinus OMZ 65 (PFK-sob), respectively. Steady-state kinetics revealed K(M) = 0. 8 mM for PFK-rat and K(M) = 0.08 mM for PFK-sob for F-6-P as the substrate. The enzymes also differ in their pH profiles: whereas the highest activity of PFK-rat was measured at pH = 8.0, the optimum pH of PFK-sob was at pH = 7.0. In addition, compared to PFK-sob, PFK-rat was more sensitive against the allosteric inhibitor ATP. PFK catalyzes a committed step of glycolysis, the main acid producing catabolic pathway. Thus, the catalytically more efficient enzyme isolated from S. sobrinus OMZ 65, especially at low pH, could explain the comparably high acidogenicity of this strain.

The effects of non-fluoridated and fluoridated milk on experimental caries in rats.

The aim of the present investigation was to determine the caries-protective potential of non-fluoridated and fluoridated milk and to compare the efficacy of different compounds of fluoride as additives to milk. OM rats were maintained in three experiments in a frequency-controlled feeding machine of König et al. (1968) or, during one study, in metabolic cages with diet MIT 200 for three weeks. They received (1) milk with Ca-Fluoride [solubilized by KA1-Sulfate], (2) NaF, (3) NaMFP, and (4) Na-Silicofluoride. Controls were supplied with water or NaF solution of the same concentration of 10 or 15 ppm F. In addition, raw milk was provided ad libitum for the rats in a preliminary test. At the beginning and the end of the experiments, the pH of milk, its fluoride concentration, the body weight gain, the caries score, the fluoride concentration of the outermost enamel surface, the percentage of the interproximal bacteria, and the fluoride ingestion and excretion were determined. The raw milk significantly reduced the animal caries score by around 40%. This effect was lower but reproducible under programmed feeding with milk of a reduced fatty content (1.5%). The addition of Ca-Fluoride, which was not totally ionized (6.5 ppm F), reduced the caries score again by around 40%. Increasing concentrations of NaF (5, 10, 15 ppm F), Na-Silicofluoride, or NaMFP showed similar caries-inhibiting effects without remarkable influence of the fluoride dosage used. The percentage of streptococci ranged from 30 to 60 in the fluoridated milk and control groups as well. The increasing fluoride deposition in the enamel reflected the various fluoride dosages offered. The rats receiving non-fluoridated milk or distilled water had a significantly higher incidence of dental caries than those receiving fluoridated milk. The permanent availability of fluoride during the animal tests caused a higher caries-inhibiting effect than in clinical human studies reported.

[Caries protective effectiveness of fluoride varnish in animal experiments and clinical research]. / Kariesprotektive Effektivität von Fluoridlack im tierexperimentellen und klinischen Versuch.

Fluoride containing varnishes represent clinically proved means for individual caries prevention by topical application due to their prolonged contact time between fluoride and enamel. The fluoride accumulation in vitro and in vivo, the inhibition of demineralization, the experimentally and clinically proved reduction of caries and the toxicological safety during varnish application are reviewed. A reduction of caries between 20-50 per cent may be registered after semiannual application of such varnishes due to their high caries protective properties.

[Caries protective effect of a NaF containing toothpaste with and without calcium carbonate polishing agent]. / Kariesprotektiver Effekt einer NaF-haltigen Zahnpaste bei gleichzeitiger Anwesenheit eines Kalziumkarbonat-Putzkörpers.

A caries preventive effect depending on the free fluoride concentration was registrated on rats using dentifrices with NaF or MFP (alone or in combination) despite the presence of CaCO3 as abrasive material because the composition of these dentifrices was changed. The free fluoride concentration of dentifrices had induced the accumulation of fluoride into enamel. The ionized fluoride content of NaF-dentifrices was unchanged for 3 years. MFP was hydrolized and had continuously released fluoride ions. The caries preventive effect which was increased by HCO3- was reproducible in correspondence with the fluoride concentration after the storage for two years.

[Plaque and gingivitis reduction by an amine fluoride/stannous fluoride combination]. / Plaque- und Gingivitisreduktion durch eine Aminfluorid/Zinnfluorid-Kombination.

A clinical study on children has demonstrated that the accumulation of plaque and the development of experimental gingivitis can be reduced by a daily mouthrinse with AmF/SnF2. Low, reversible yellowish tooth staining can almost be prevented by mechanical oral hygiene. The efficacy of AmF/SnF2 was nearly the same as chlorhexidine and the F combination can be recommended for preventive plaque control, especially on high-risk patients.

[The establishment efficiency of S. sobrinus OMZ 176 in a model caries experiment on the Osborne-Mendel rat]. / Etablierungseffizienz von S. sobrinus OMZ 176 im Kariesmodellversuch an der Osborne-Mendel Ratte.

S. sobrinus OMZ 176 was inoculated in young OM rats during tooth eruption in two experiments and the microbial composition of dental plaque as well as the caries decay was estimated after 25 days on cariogenic sucrose rich diet. Germs were reproducibly established in the oral cavity by such way. The resulting caries decay correlated with the streptococci in the dental plaque. Due to this fact it seems to be necessary to identify not only the inoculated microorganisms at the end of each animal experiment but also to estimate the qualitative composition of the whole dental flora which may have an essential cariogenic effect.

[Intraoral pH measurement by determination of acidogenic potentials of dietary materials]. / Intra-orale pH-Messung zur Bestimmung des azidogenen Potentials von Nahrungsmitteln.

The intra-oral production of acid by plaque bacteria from sucrose, glucose and sorbitol and test products with sugar substitutes as well was estimated by pH-telemetry which permits the digital registering and collection of data. A pH-drop was not observed when sorbitol or xylitol were offered as a substrate to the dental plaque. The small differences of intensity and duration of the telemetric estimated acid production by dental plaque due to the test products (with sucrose or sorbitol/glucose) exhibited different cariogenic challenge in the animal experiment and in the intra-oral cariogenicity test, but with high probability they have not any practical significance for the preventive dietetic recommendations.

[Oral Streptococci - a scheme for the identification of Streptococcus mutans]. / Orale Streptokokken - Ein Beitrag zur Identifizierung von Streptococcus mutans.

A reliable simple scheme for the rapid identification of certain species of oral streptococci has been developed and compared with biochemical and physiological results of 45 well known clinical isolates and stock strains. Moreover, a method for the determination of H2O2 production was tested. With selected reactions as for instance acid formation in mannitol and raffinose broth, hydrolysis of arginine and esculin, the production of peroxidase, and the resistance of bacitracin the species S. rattus, S. sobrinus, S. mutans, S. cricetus, S. ferus, S. milleri, S. mitis, S. sanguis, S. mitior, and S. salivarius were differentiated.

[The plaque- and caries-inhibiting efficacy of an amine fluoride/tin fluoride combination in an animal experiment on rats]. / Plaque und Karies inhibierende Wirksamkeit einer Aminfluorid/Zinnfluorid-Kombination im Tierversuch an der Ratte.

A similar plaque inhibition by was found after daily topical application of CHX or AmF/SnF2 in comparison with a placebo on rats. The fluoride combination exhibited a significant caries protective influence which was equal to AmF when the last was used in the same concentration. More concentrated AmF has shown a higher caries reducing effect and higher fluoride accumulation in the enamel surface layer of teeth. AmF/SnF2 could been recommended to individual plaque control with parallel caries protective effect.

[The spectrum of S. mutans OMZ 176 products from different mono- and disaccharides]. / Das Produktspektrum von S. mutans OMZ 176 aus verschiedenen Mono- und Disacchariden.

S. mutans OMZ 176 produced from mono-, disaccharides and hexitols in microbiological culture up to the log. growth phase different amounts of acid. Lactate was the gas chromatographically analyzed prevailing end product. Microbial suspensions of the same living mass prepared from the cultures produced homofermentatively lactate from glucose and sucrose whereas all other substrates (galactose, lactose, sorbitol, mannitol) were turned over partial heterofermentatively.

[Gas chromatographic analysis of the S. mutans product spectrum from glucose turnover]. / Gaschromatographische Analyse des Produktspektrums von S. mutans aus Glucose.

In addition to other acids lactate was detected as prevailing end product in glucose containing broth of 8 S. mutans strains. The total acid amounts differed depending on the microbial origin. Further quantitative and qualitative differences existed between acidic products of the pH-stat controlled reaction with glucose as substrate and defined germ suspensions. S. mutans LM 7 showed the most strongly heterofermentative pathway.