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As the thick biofilm in the presence of fermentable carbohydrates is the main etiological factor of dental caries, the frequent and systematic removal of this colony by means of an effective biofilm control should result in the prevention of caries lesions or in the arrest of the local carious process. However, the role of biofilm control in the management of dental caries has been questioned. This chapter will discuss the biofilm control and oral hygiene practices on root surfaces. Laboratory and clinical studies describing the effect of biofilm control and oral hygiene practices on the arrestment of root carious lesions are described. Epidemiological surveys evaluating the association between oral hygiene and root caries are discussed. Finally, some aspects on chemical biofilm control are also presented., (© 2017 S. Karger AG, Basel.)

Objectives: The present study aimed, using a questionnaire, to assess and compare behaviour, attitudes and beliefs of French, German and Norwegian dentists regarding deep carious lesion management., Materials and Methods: A mail survey was applied to simple random national samples of dentists. Descriptive analysis and logistic regression analysis were performed., Results: Sample size was 661 (response rate, 33 %) in France, 622 (25 %) in Germany and 199 (33 %) in Norway. Hardness was the criterion used most often for assessing carious tissue removal in all three countries (>95 %), with most dentists aiming for only hard dentine remaining at the pulpal wall (>66 %); dentine colour was not found relevant by most respondents. The majority of French and German practitioners (>66 %) would perform complete excavation even for deep lesions, while most Norwegian dentists (84 %) opted for stepwise excavation. Most dentists thought complete removal was required to avoid lesion progression and were uncertain if remaining sealed bacteria would harm the pulp. Treatment decisions were guided by prior experience and familiarity. For example, stepwise removal was performed less often by dentists who were male, French, German or those in the private sector., Conclusions: Less invasive strategies for managing deep lesions have not widely entered clinical practice in France and Germany. Underlying beliefs shape decision-making., Clinical Relevance: The present study is the first of its nature to analyse and compare deep carious lesion management between three European countries. It shows that there is an urgent need to practically educate dentists in less invasive strategies.

Variations in organic and inorganic composition and morphology may determine different susceptibilities of root surfaces to caries. Subsequent to gingival recession, root surfaces become exposed and those areas where Sharpey's fibers system was once inserted into the cementum are converted into canals for microbial penetration. In the presence of a cariogenic root biofilm, the fermentable carbohydrate from diet is converted into organic acid, and the root caries lesion is initiated in the exposed root site. We will revisit here the structural, biochemical, and histopathological specificities of root caries. Likewise enamel, the root surface exchange minerals with oral fluids, resulting in a subsuperficial root caries lesion. After mineral loss, the collagen is degraded and the lesion progresses. The specificities regarding the critical pH for demineralization of root hard tissues, the influence of cementum loss for lesion progression, and the organic matrix degradation will be discussed in this chapter. The tissue-related phenomena would create lesion with a unique histopathology. Active and arrested root carious lesions will be discussed through the gradual development from the cementum to dentin., (© 2017 S. Karger AG, Basel.)

Background: The studies of the distribution of Actinomyces spp. on carious and non-carious root surfaces have not been able to confirm the association of these bacteria with root caries, although they were extensively implicated as a prime suspect in root caries., Objective: The aim of this study was to observe the gene expression of Actinomyces spp. in the microbiota of root surfaces with and without caries., Design: The oral biofilms from exposed sound root surface (SRS; n=10) and active root caries (RC; n=30) samples were collected. The total bacterial RNA was extracted, and the mRNA was isolated. Samples with low RNA concentration were pooled, yielding a final sample size of SRS=10 and RC=9. Complementary DNA (cDNA) libraries were prepared and sequenced on an Illumina(®) HiSeq 2500 system. Sequence reads were mapped to eight Actinomyces genomes. Count data were normalized using DESeq2 to analyse differential gene expression applying the Benjamini-Hochberg correction (false discovery rate [FDR]<0.001)., Results: Actinomyces spp. had similar numbers of reads (Mann-Whitney U-test; p>0.05), except for Actinomyces OT178 (p=0.001) and Actinomyces gerencseriae (p=0.004), which had higher read counts in the SRS. Genes that code for stress proteins (clp, dnaK, and groEL), enzymes of glycolysis pathways (including enolase and phosphoenolpyruvate carboxykinase), adhesion (Type-2 fimbrial and collagen-binding protein), and cell growth (EF-Tu) were highly - but not differentially (p>0.001) - expressed in both groups. Genes with the most significant upregulation in RC were those coding for hypothetical proteins and uracil DNA glycosylase (p=2.61E-17). The gene with the most significant upregulation in SRS was a peptide ABC transporter substrate-binding protein (log2FC=-6.00, FDR=2.37E-05)., Conclusion: There were similar levels of Actinomyces gene expression in both sound and carious root biofilms. These bacteria can be commensal in root surface sites but may be cariogenic due to survival mechanisms that allow them to exist in acid environments and to metabolize sugars, saving energy.

Objectives: To assess the association between gingival recession (GR) and oral health-related quality of life (OHRQoL) in a Brazilian population of adults., Methods: A representative sample from Porto Alegre city was drawn in 2011 using a multistage probability sampling strategy. For this study, 740 individuals, 35-59 years of age and with ≥6 teeth, were included. GR was assessed by two calibrated examiners at four sites in all present teeth. The Oral Health Impact Profile (OHIP-14) was used to assess OHRQoL. OHIP-14 was dichotomized using 'fairly often' as the cutoff point for a negative impact. Multiple logistic regression models were fitted to define which descriptors of GR were associated with the dichotomous outcome of OHIP-14, including dentine hypersensitivity in separate models, adjusting for age, gender, socioeconomic status, smoking, dental care, and missing teeth., Results: Mean OHIP was significantly higher for individuals with ≥1 tooth with GR ≥2, ≥3, ≥4, and ≥5 mm. Individuals with ≥1 tooth with GR ≥2 mm had approximately two times higher chance of having a negative impact than individuals without GR of this threshold [odds ratio (OR) = 1.99, 95% confidence interval (CI) 1.05-3.78]. When buccal and proximal sites were analyzed separately, the presence of GR was significantly associated with worst quality of life only in anterior and not in posterior teeth. GR in the lower arch had no impact on OHRQoL. GR ≥2 mm affected only physical pain (OR = 2.61; 95% CI 1.06-6.42), whereas GR ≥4 mm affected functional limitation, physical pain, psychological discomfort, physical and psychological disabilities, with ORs ranging from 1.43 to 1.91. Dentine hypersensitivity alone was not associated with OHRQoL, but it modified the association between GR and OHIP when present concomitantly with GR, mainly in buccal sites., Conclusions: OHRQoL is poorer in this adult population in the presence of GR, mainly in upper and anterior teeth. Dentine hypersensitivity and esthetics were found to be factors linking GR to OHRQoL., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The International Caries Consensus Collaboration undertook a consensus process and here presents clinical recommendations for carious tissue removal and managing cavitated carious lesions, including restoration, based on texture of demineralized dentine. Dentists should manage the disease dental caries and control activity of existing cavitated lesions to preserve hard tissues and retain teeth long-term. Entering the restorative cycle should be avoided as far as possible. Controlling the disease in cavitated carious lesions should be attempted using methods which are aimed at biofilm removal or control first. Only when cavitated carious lesions either are noncleansable or can no longer be sealed are restorative interventions indicated. When a restoration is indicated, the priorities are as follows: preserving healthy and remineralizable tissue, achieving a restorative seal, maintaining pulpal health, and maximizing restoration success. Carious tissue is removed purely to create conditions for long-lasting restorations. Bacterially contaminated or demineralized tissues close to the pulp do not need to be removed. In deeper lesions in teeth with sensible (vital) pulps, preserving pulpal health should be prioritized, while in shallow or moderately deep lesions, restoration longevity becomes more important. For teeth with shallow or moderately deep cavitated lesions, carious tissue removal is performed according toselective removal to firm dentine.In deep cavitated lesions in primary or permanent teeth,selective removal to soft dentineshould be performed, although in permanent teeth,stepwise removalis an option. The evidence and, therefore, these recommendations support less invasive carious lesion management, delaying entry to, and slowing down, the restorative cycle by preserving tooth tissue and retaining teeth long-term., (© International & American Associations for Dental Research 2016.)

The management of occlusal caries still remains a major challenge for researchers as well as for general practitioners. The present paper reviews and discusses the most up-to-date knowledge and evidence of the biological principles guiding diagnosis, risk assessment, and management of the caries process on occlusal surfaces. In addition, it considers the whole spectrum of the caries process on occlusal surfaces, ranging from the molecular ecology of occlusal biofilms to the management of deep occlusal caries lesions. Studies using molecular methods with focus on biofilms in relation to occlusal caries should explore the relationship between the function and the structural composition of these biofilms to understand the role of occlusal biofilms in caries development. State-of-the-art measures to evaluate risk for occlusal caries lesion activity, caries incidence, and progression should include the assessment of the occlusal biofilm and the stage of tooth eruption. Careful clinical examination of non-cavitated lesions, including assessment of the lesion activity status, remains the major tool to determine the immediate treatment need and to follow on the non-operative treatment outcome. Even medium occlusal caries lesions in the permanent dentition may be treated by non-invasive fissure sealing. By extending the criteria for non-invasive treatments, traditional restoration of occlusal surfaces can be postponed or even avoided, and the dental health in children and adolescents can be improved. Selective removal (incomplete) to soft dentin in deep carious lesions has greater success rates than stepwise excavation. Selective (complete) removal to firm dentin has a lower success rate due to increased pulp exposure., (© 2016 S. Karger AG, Basel.)

Objective: To assess the epidemiology and risk indicators for dental erosion among 12-year-old schoolchildren in South Brazil., Methods: A population-based cross-sectional survey was conducted in Porto Alegre, Brazil, using a representative sample of 12-year-old schoolchildren (n = 1,528). Dental erosion was recorded according to the Basic Erosive Wear Examination (BEWE) index. Parents answered questions on socio-economic status, brushing frequency and general health. Schoolchildren answered questions on dietary habits. Anthropometric data were collected. Statistical analysis included logistic and Poisson regression models., Results: The prevalence of dental erosion was 15% [95% confidence interval (95% CI): 13.6-16.5], being mainly mild erosion. Boys [odds ratio (OR) = 1.57, 95% CI: 1.17-2.10], private school attendees (OR = 1.45, 95% CI: 1.01-2.06) and schoolchildren reporting the daily consumption of soft drinks (OR = 5.04, 95% CI: 1.17-21.71) were more likely to have at least one tooth with dental erosion. Gender [boys, rate ratio (RR) = 1.66, 95% CI: 1.28-2.17], type of school (private, RR = 1.89, 95% CI: 1.53-2.35), the consumption of soft drinks (sometimes: RR = 5.27, 95% CI: 1.46-19.05; daily: RR = 6.82, 95% CI: 1.39-33.50) and the daily consumption of lemon (RR = 1.49, 95% CI: 1.11-2.00) were significantly associated with the number of affected surfaces., Conclusions: The present study found a moderate prevalence of dental erosion among young schoolchildren, with mild erosion being the most prevalent condition. Socio demographic variables and dietary habits were associated with dental erosion in this population., (© 2015 FDI World Dental Federation.)

Objective: To evaluate the effectiveness of a treatment for non-cavitated occlusal lesions on erupting permanent molars and to verify whether initial eruption stage and final biofilm accumulation are associated with lesions activity after the treatment., Methods: Forty-eight patients aged from 5 to 13 years old were selected. Molars with active non-cavitated lesions on the occlusal surface were classified according to eruption stage. Patients received a treatment for 4 weeks based on oral health instructions and fluoride applications. Three weeks after the end of the treatment, 39 patients were reassessed and lesion activity status and biofilm accumulation were recorded. Odds ratios were obtained using generalized estimating equations with logistic link function., Results: Partially erupted molars were more prone to remain caries-active than molars in full occlusion (E1: OR = 301.1; E2: OR = 49.0 and E3: OR = 1107.3). High biofilm accumulation was associated with the presence of active lesions., Conclusions: Biofilm accumulation and eruption stage strongly influenced the effectiveness of a treatment for dental caries., (© 2014 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: This study aimed to evaluate the effect of fluoridated dentifrice (FD) and mouthwash (FM) under different treatment regimens on root caries (RC) inhibition., Methods: Dual-species biofilms formed by Streptococcus mutans and Lactobacillus casei were grown on the surface of bovine root dentine slabs which were exposed during 3 consecutive days to one of the following treatments: T1-distilled and deionized water 3×/day; T2-FD (1450ppmF) 2×/day; T3-FD 2×/day+FM (226ppmF) 1×/day; T4-FD 3×/day. Viable microorganisms counts were performed after 4 days of biofilm formation. Percentage of surface microhardness change (%SMC), lesion depth (LD; μm), integrated mineral loss (IML; vol%×μm) and the percentages of change (Δ%) in the ratio of fluorapatite (FAp/amide) and hydroxiapatite (HAp/amide) were calculated., Results: Minor changes were found on microbial counts in response to different treatments (p<0.05). %SMC in T4 was statistically lower compared with T2, but with no significant difference compared with T3. LD of slabs treated with T4 was statistically lower compared with T2 and T3, which were not significantly different between them. No significant differences were found for IML, FAp and HAp among the fluoridated treatments (p>0.05)., Conclusion: The use of FD 3×/day may be more effective than the use of FD 2×/day or the tested association between FD and FM on RC inhibition., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Purpose: To determine the correlation between the presence of radiolucent areas (RA) beneath composite restorations and gaps and remaining demineralized tissue (RDT)., Methods: 50 extracted teeth (sound and carious) were studied. After caries removal, cavities were filled. Artificial cavities were created and filled in the sound teeth. Samples were sectioned and analyzed with stereomicroscopy., Results: Gap/RDT was observed in 38.9% [95% confidence interval (CI) =28.2-50.5] and 68.9% (95% CI = 57-78.6) of sound and carious teeth, respectively, (P = 0.001). Gap/RDT was associated with RA (P < 0.001). Sensitivity, specificity, predictive positive values (PPV), predictive negative value, and accuracy for carious teeth were 77.1% (95% CI = 63.7-87.3), 54.5% (95% CI = 33.8-74.1), 78.7% (95% CI = 65.3- 88.7), 52.2% (95% CI = 32.1-71.7), and 70% (95% CI = 58.5-79.8), and for sound teeth were 73.7% (95% CI = 62.9-82.6), 59.1% (95% CI = 47.0-70.4), 67.5% (95% CI = 56.9-76.9), 66.1% (95% CI = 53.4-77.3), and 66.9% (95% CI = 58.9-74.3). Only the PPV differed between the sound and carious teeth (P = 0.024).There was a correlation between radiolucency and gap/RDT, but a high number of false positives were found.

It is known that many pathogens produce high-affinity iron uptake systems like siderophores and/or proteins for utilizing iron bound to heme-containing molecules, which facilitate iron-acquisition inside a host. In mutualistic digestive-tract associations, iron uptake systems have not been as well studied. We investigated the importance of two iron utilization systems within the beneficial digestive-tract association Aeromonas veronii and the medicinal leech, Hirudo verbana. Siderophores were detected in A. veronii using chrome azurol S. Using a mini Tn5, a transposon insertion in viuB generated a mutant unable to utilize iron using siderophores. The A. veronii genome was then searched for genes potentially involved in iron utilization bound to heme-containing molecules. A putative outer membrane heme receptor (hgpB) was identified with a transcriptional activator, termed hgpR, downstream. The hgpB gene was interrupted with an antibiotic resistance cassette in both the parent strain and the viuB mutant, yielding an hgpB mutant and a mutant with both iron uptake systems inactivated. In vitro assays indicated that hgpB is involved in utilizing iron bound to heme and that both iron utilization systems are important for A. veronii to grow in blood. In vivo colonization assays revealed that the ability to acquire iron from heme-containing molecules is critical for A. veronii to colonize the leech gut. Since iron and specifically heme utilization is important in this mutualistic relationship and has a potential role in virulence factor of other organisms, genomes from different Aeromonas strains (both clinical and environmental) were queried with iron utilization genes of A. veronii. This analysis revealed that in contrast to the siderophore utilization genes heme utilization genes are widely distributed among aeromonads. The importance of heme utilization in the colonization of the leech further confirms that symbiotic and pathogenic relationships possess similar mechanisms for interacting with animal hosts.

Three anaerobic bacterial strains were isolated from the digestive tract of the medicinal leech Hirudo verbana, using mucin as the primary carbon and energy source. These strains, designated M3(T), M4 and M6, were Gram-stain-negative, non-spore-forming and non-motile. Cells were elongated bacilli approximately 2.4 µm long and 0.6 µm wide. Growth only occurred anaerobically under mesophilic and neutral pH conditions. All three strains could utilize multiple simple and complex sugars as carbon sources, with glucose fermented to acid by-products. The DNA G+C contents of strains M3(T), M4 and M6 were 44.9, 44.8 and 44.8 mol%, respectively. The major cellular fatty acid of strain M3(T) was iso-C15 : 0. Phylogenetic analysis of full-length 16S rRNA gene sequences revealed that the three strains shared >99 % similarity with each other and represent a new lineage within the family Rikenellaceae of the order Bacteroidales, phylum Bacteroidetes. The most closely related bacteria to strain M3(T) based on 16S rRNA gene sequences were Rikenella microfusus DSM 15922(T) (87.3 % similarity) and Alistipes finegoldii AHN 2437(T) (87.4 %). On the basis of phenotypic, genotypic and physiological evidence, strains M3(T), M4 and M6 are proposed as representing a novel species of a new genus within the family Rikenellaceae, for which the name Mucinivorans hirudinis gen. nov., sp. nov. is proposed. The type strain of Mucinivorans hirudinis is M3(T) ( = ATCC BAA-2553(T) = DSM 27344(T))., (© 2015 IUMS.)

The aim of this study was to assess the prevalence, extent, severity, intraoral distribution and risk indicators for erosive tooth wear (ETW) among 12-year-old schoolchildren from Montevideo, Uruguay. A population-based, cross-sectional survey was conducted using a representative sample of 1,136 12-year-old schoolchildren attending public and private schools. Parents answered questions on socioeconomic status and general health. Schoolchildren answered questions on dietary and oral hygiene habits. Two calibrated examiners recorded ETW on permanent teeth according to the Basic Erosive Wear Examination (BEWE) score system. Logistic regression models were performed to assess the association between the predictor variables and the prevalence of ETW (overall and severe ETW). Odds ratios (OR) and the respective 95% confidence intervals (CI) were estimated. The prevalence of ETW was 52.9%, being mild erosion (BEWE = 1) in the vast majority of cases (48.5%). Severe erosion (BEWE ≥2) was detected in 4.4% of schoolchildren. The overall prevalence of ETW differed significantly between categories of gender and socioeconomic status, but only between gender in the severe ETW analysis. The overall extent of ETW was significantly different between categories of gender, socioeconomic status, and swish before swallow. The extent of severe ETW differed between categories of swish before swallow and brushing frequency. In the logistic regression analysis, no association was found between the studied variables and the overall prevalence of ETW. Males were more likely to have severe ETW than females (OR = 3.22, 95% CI = 1.50-6.89). ETW may be considered a public health problem among 12-year-old-Uruguayan schoolchildren.

Aim: To describe estimates and determine risk indicators of gingival recession in the urban population of Porto Alegre, Brazil., Materials and Methods: A representative sample of 1023 adults 35 years and older was obtained using a multistage probability sampling strategy. A structured questionnaire was applied and a clinical examination was performed at four sites of all teeth present. Complex survey commands were used for the estimation of gingival recession (GR) and during risk assessment., Results: GR ≥1 mm affected 99.7% of subjects. The percentage of subjects with ≥1 tooth with GR ≥3 mm and ≥5 mm was 75.4% and 40.7%, respectively. 67.6%, 27.8% and 9.5% of teeth per subject showed GR ≥1 mm, ≥3 mm and ≥5 mm, respectively. Older age, male gender, smoking exposure, poor self-reported oral hygiene, history of periodontal treatment and high percentage of calculus were significant risk indicators for GR found after multivariable risk assessment. When buccal GR was analysed separately, only gender, age, smoking and high education were significant risk indicators for GR, whereas variables related to oral hygiene were not associated., Conclusion: GR is highly prevalent in this Brazilian population. Preventive strategies for GR may target a variety of socio-demographic, behavioural and clinical risk indicators., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Dentin hypersensitivity (DH) is a clinical condition with potential implications for patients. However, little is known about its occurrence and determinants in the general population. The aim of this study is to assess the prevalence and risk indicators of DH in Porto Alegre, Brazil., Methods: A representative multistage probability sample of 1,023 adults aged ≥ 35 years was obtained. Individuals were interviewed and clinically examined in their homes. DH was assessed dichotomously in all present teeth by a blast of air and a manual probe. Teeth restored with crowns and presenting with carious cavitation were excluded. Survey logistic regression using sampling weights was applied to assess demographics and behavioral and clinical determinants., Results: Overall prevalence estimates for DH diagnosed by air and probe were 33.4% and 34.2%. DH affected ≈ 1 tooth per individual, and approximately 10% of teeth with gingival recession (GR) had DH. In a multivariable model for DH diagnosed with air, females had increased chance of DH (odds ratio [OR] = 2.14; 95% confidence interval [CI] = 1.57 to 2.91). Smoking, periodontal treatment, and GR were also associated with increased DH risk. The chance of DH was lower (OR = 0.47, 95% CI = 0.29 to 0.76) among individuals ≥ 60 than among those aged 35 to 49 years. Oral hygiene practices, socioeconomic and education status, dental visits, and gingival inflammation were not associated with DH., Conclusions: DH may be considered a concern in a Brazilian general population. Reduction of DH may be achieved by smoking cessation and periodontal health improvements.

Background: There are at least three distinct European leech species used medicinally: Hirudo medicinalis, H. orientalis, and H. verbana. Infection caused by leech microbiota is the most widely reported complication. Few studies have reported the culturable and unculturable bacteria and examined the antibiotic resistances in H. orientalis., Methods: Following stratified random sampling from a major worldwide leech supplier, Hirudo orientalis leeches were identified by visual comparison and amplification and sequencing the cox1 locus. Combined culture and culture-independent approaches were used to characterize the microbiota of the midgut, and bacterial gyrB sequences from distinct colonies were used to identify the Aeromonas isolates. Nonculturable studies involved clone libraries of 16S rRNA genes, and Etests were used to investigate antibiotic sensitivities., Results: Analysis of 16S rRNA gene clone libraries revealed the presence of several species in the intraluminal fluid of the crop, including a new finding of Morganella morganii, with Rikenella-like (35 percent) and Aeromonas veronii (38 percent) dominant members. The intestinum contained bacteria not previously isolated from the leech: Magnetospirillium species and Roseospira marina. Etests showed all A. veronii isolates were sensitive to ciprofloxacin, with either a complete or intermediate resistance to Augmentin., Conclusions: The authors show diverse microbiota in the leech digestive tract. The pathogenic potential of the additional gut symbionts isolated in this study is yet to be elucidated; however, M. morganii, which is a known human pathogen, is a new finding. In addition to adding to the knowledge base regarding antibiotic sensitivities, this article serves as an update to the reconstructive surgeon regarding leech therapy.

The aim of this study was to compare the genotypic diversity and virulence traits of Streptococcus mutans isolated from carious dentin before and after partial dentin caries removal (PDR) and sealing. Carious dentin samples were obtained three months before and after the PDR and cavity sealing. Up to seven isolates of each morphological type of S. mutans were selected and strain identity was confirmed using gtfB primer. Genotyping was performed by arbitrary primer-PCR (AP-PCR). Acidogenesis and acidurance of the genotypes were evaluated as virulence traits. A paired t-test and a Wilcoxon test were used to compare the virulence of genotypes. A total of 48 representative S. mutans isolates were genotyped (31 before and 17 after the sealing). At least one of the genotypes found before the sealing was also found on dentin after the sealing. The number of genotypes found before the sealing ranged from 2 to 3 and after the sealing from 1 to 2 genotypes. No difference was observed in the acidogenesis and acidurance between genotypes isolated before and after the sealing. In conclusion, genotypic diversity of S. mutans decreased after the PDR and sealing, but the virulence traits of S. mutans remained unchangeable.

This single-blind, randomized, crossover study aimed at assessing the long-term fluoride concentrations in saliva and in dental biofilm after different home-use fluoride treatments. The study volunteers (n = 38) were residents of an area with fluoridated drinking water. They were administered four treatments, each of which lasted for one week: twice-daily placebo dentifrice, twice-daily fluoride dentifrice, twice-daily fluoride dentifrice and once-daily fluoride mouthrinse, and thrice-daily fluoride dentifrice. At the end of each treatment period, samples of unstimulated saliva and dental biofilm were collected 8 h after the last oral hygiene procedure. Fluoride concentrations in saliva and dental biofilm were analyzed using a specific electrode. The fluoride concentrations in saliva and dental biofilm 8 h after the last use of fluoride products did not differ among treatments. The results of this study suggest that treatments with home-use fluoride products have no long-term effect on fluoride concentrations in saliva and in dental biofilm of residents of an area with a fluoridated water supply.

The aim of this study was to evaluate the effect of a commercial lactose-containing stevioside sweetener on biofilm acidogenicity in vivo. Nine volunteers refrained from brushing their teeth for 3 days in five phases. On the 4th day of each phase, the pH of the biofilm was measured by the "Strip method". Interproximal plaque pH was measured before and up to 60 minutes after a 10 mL mouthrinse for 1 minute with the test solutions: I - sweetener with 93% lactose and 7% stevioside; II - sweetener with 6.8% saccharin, 13.6% cyclamate, and 0.82% stevioside; III - 18% sucrose solution (positive control); IV - mineral water (negative control); and V- 93% lactose solution. The results revealed that the most pronounced pH fall was found with sucrose (positive control), followed by the 93% lactose solution, the sweetener with lactose + stevioside, the sweetener with saccharin + cyclamate + stevioside, and finally water (negative control). According to the area under the curve, the two sweeteners containing stevioside were significantly different, and the sweetener with lactose + stevioside was significantly different from water but not from sucrose. The critical pH for dentin demineralization (pH ≤ 6.5) was reached by all volunteers after rinsing with sucrose solution, lactose solution, and the stevioside + lactose sweetener. Analysis of the data suggests that lactose-containing stevioside sweeteners may be cariogenic, especially to dentin.

This population-based cross-sectional study aimed to assess the prevalence and risk indicators for tooth loss due to dental caries among 12-year-old schoolchildren from South Brazil. 1,528 out of 1,837 (participation rate = 83.17%) schoolchildren were included. Tooth loss prevalence was 5.81% (95% CI = 3.71-8.98) and 0.08 (95% CI = 0.04-0.12) teeth were missing. Schoolchildren with low socioeconomic status (OR = 2.28, 95% CI = 1.23-4.21), who repeated years in school (OR = 1.56, 95% CI = 1.01-2.42), and with gingivitis (OR = 1.81, 95% CI = 1.33-2.45) were more likely to have missing teeth. Schoolchildren brushing 2 times/day (OR = 0.78, 95% CI = 0.64-0.96) or more (OR = 0.49, 95% CI = 0.33-0.74), and those with dental insurance or private dentists (OR = 0.60, 95% CI = 0.39-0.93) were less likely to present missing teeth. © 2014 S. Karger AG, Basel., (© 2014 S. Karger AG, Basel.)

Article Title and Bibliographic Information: Incomplete caries removal: a systematic review and meta-analysis. Schwendicke F, Dörfer CE, Paris S. J Dent Res 2013;92(4):306-14., Reviewers: Marisa Maltz, DDS, MSc, Luana Severo Alves, DDS, MSc, PhD PURPOSE/QUESTION: The authors conducted a meta-analysis of randomized controlled trials comparing incomplete and complete caries removal on the management of caries lesions in primary and permanent teeth, Source of Funding: The study was funded by the authors and their institutions, Type of Study/design: Systematic review with meta-analysis, Level of Evidence: Level 1: Patient-oriented evidence, Strength of Recommendation Grade: Grade A: Consistent, patient-oriented evidence., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Article Title and Bibliographic Information: Prognostic factors for clinical outcomes according to time after direct pulp capping. Cho SY, Seo DG, Lee SJ, Lee J, Lee SJ, Jung IY. J Endod 2013 Mar;39(3):327-31., Reviewers: Marisa Maltz, DDS, MSc, Odontology Doctor,Luana Severo Alves, DDS, MSc, PhD PURPOSE/QUESTION: Permanent teeth with cariously exposed pulps were treated with direct pulp capping and monitored over time in order to assess the treatment outcome and the potential factors contributing to the pulpal survival, Source of Funding: The study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0005090 and 2011-0028067) TYPE OF STUDY/DESIGN: Retrospective cohort study, Level of Evidence: Level 2: Limited-quality patient-oriented evidence (cohort study), Strength of Recommendation Grade: Not applicable., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Traumatic dental injury (TDI) has been considered a significant problem in youth, not only because of its consequences to the craniofacial structures but also for its potential impact on the quality of life of affected individuals., Aim: The aim of this study was to investigate the impact of TDI with treatment needs on the oral health-related quality of life (OHRQoL) of South Brazilian schoolchildren., Design: A cross-sectional study was performed in Porto Alegre, Brazil, using a multistage probability sampling strategy. Of 1837 eligible 12-year-old schoolchildren attending public and private schools, 1528 were examined. OHRQoL was assessed by the Brazilian version of the Child Perceptions Questionnaire for 11-to 14-year-old children (CPQ11-14) - 16-item short form. Clinical examination was conducted to assess the presence of TDI in permanent incisors (Children's Dental Health Survey criteria), malocclusion, and dental caries. Parents/legal guardians answered questions on socioeconomic status. Statistical analyses were performed using Poisson regression models., Results: The overall CPQ11-14 score was not associated with TDI. In the functional limitations domain, individuals presenting TDIs with treatment needs experienced significantly higher mean CPQ11-14 than individuals with no TDI or without treatment needs (RR = 1.21; 95% CI = 1.05-1.39), after adjusting for malocclusion, dental caries, gender, and socioeconomic status. No other domains were associated with TDI., Conclusions: This study revealed that TDI with treatment needs negatively affects the OHRQoL in this population of 12-year-old schoolchildren and that this impact is related to oral functions., (© 2012 John Wiley & Sons Ltd, BSPD and IAPD.)

Objectives: To assess the association between weight status and dental caries among 12-year-old Brazilian schoolchildren., Methods: This cross-sectional study was carried out in Porto Alegre using a multistage probability sampling strategy to draw a representative sample of schoolchildren attending public and private schools. Data on demographics, socioeconomic status, oral hygiene habits, anthropometrics, and dental caries were collected. Overweight and obesity were defined according to WHO categories for BMI (body mass index)-for-age Z-scores. Survey Poisson regression models were used to assess the association between weight status and dental caries. Estimates were adjusted for gender, socioeconomic status, and brushing frequency. Prevalence ratios (PR), rate ratios (RR) and 95% confidence intervals (95% CI) were reported., Results: One thousand five hundred and twenty-eight of 1837 eligible schoolchildren were examined. Prevalence of overweight and obesity were 22.15% (95% CI = 20.59-23.72) and 13.61% (95% CI = 11.44-15.78), respectively. Caries experience was observed in 55.23% (95% CI = 45.26-65.19) of children. Schoolchildren presented, on average, 1.39 (95% CI = 1.07-1.71) decayed, missing or filled teeth. No significant differences in caries experience or extent were observed among BMI groups. After adjusting for important cofactors, weight status was not associated with caries prevalence (overweight, PR = 0.99; 95% CI = 0.89-1.10; obese, PR = 1.00; 95% CI = 0.87-1.16) or caries extent (overweight, RR = 0.91; 95% CI = 0.74-1.12; obese, RR = 0.86; 95% CI = 0.72-1.04)., Conclusions: Our findings indicate that overweight and obese adolescents should not be regarded as at higher risk of dental caries in this population., (© 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

An increasing prevalence of traumatic dental injury (TDI) has been reported in the last few decades. The aim of this study was to assess the prevalence and severity of TDI and its association with socio-demographics and physical characteristics in the anterior permanent teeth of 12-year-old Brazilian schoolchildren. A cross-sectional study was carried out in a population-based sample of 1528 subjects attending 33 public and nine private schools (response rate of 83.17%). A single calibrated examiner performed the clinical examinations at the schools and recorded the TDI index (Children's Dental Health Survey criteria), overjet and lip coverage. Height and weight were measured to calculate the body mass index (BMI). Parents/legal guardians answered a questionnaire containing socio-demographic questions. The relationships among TDI, socio-demographic variables and physical characteristics were assessed by survey Poisson regression models. The prevalence of TDI was 34.79% (mild trauma = 24.37%; severe trauma = 10.43%). Male schoolchildren (RR = 1.41, 95% CI = 1.23-1.61, P = 0.002) and schoolchildren from low socioeconomic status (RR = 1.32, 95% CI = 1.07-1.64, P = 0.021) were more likely to present at least one tooth with TDI, whereas students attending 7th grade (advanced students) were less likely to experience TDI (RR = 0.59, 95% CI = 0.43-0.82, P = 0.012). Regarding the severity analysis, students of mid-high (RR = 1.46, 95% CI = 1.09-1.94, P = 0.022), mid-low (RR = 1.68, 95% CI = 1.01-2.77, P = 0.045) and low (RR = 1.78, 95% CI = 1.11-2.85, P = 0.027) socioeconomic status were more likely to have mild trauma when compared with schoolchildren of high socioeconomic status. No significant association between severe trauma and socioeconomic status was observed. In conclusion, this study showed a high prevalence of TDI in 12-year-old Brazilian schoolchildren. Socio-demographic data and school achievement were associated with TDI., (© 2012 John Wiley & Sons A/S.)

Objectives: To assess the association between dental caries treatment, intraoral distribution and oral health-related quality of life (OHRQoL) of 12-year-old South Brazilian schoolchildren., Methods: This crosssectional survey used a multistage probability sampling strategy to select a representative sample of schoolchildren from Porto Alegre, southern Brazil. Data were collected from September 2009 to December 2010, and 1528 of 1837 eligible schoolchildren attending public and private schools participated. Clinical examination was conducted to assess dental caries experience (DMFT). OHRQoL was assessed by a self-reported 16-item Child Perception Questionnaire (CPQ11–14). Parents/legal guardians answered questions on socio-economic status. Survey negative binomial regression models were used to assess the association between CPQ11–14 scores and caries treatment status (treated/untreated) and intraoral distribution (anterior/posterior). Estimates were controlled for gender and socioeconomic status., Results: Compared to schoolchildren without treatment needs, individuals with treated caries presented an improved OHRQoL (overall CPQ11 –14, adjusted RR = 0.90, 95%CI = 0.85–0.96; functional limitations, adjusted RR = 0.86, 95%CI = 0.75–0.99; emotional well-being, adjusted RR = 0.89, 95% CI = 0.80–0.99), whereas those with untreated caries presented a poorer OHRQoL (oral symptoms, adjusted RR = 1.06, 95%CI = 1.02–1.10; emotional well-being, adjusted RR = 1.09, 95%CI = 1.01–1.20). Individuals with caries in anterior teeth experienced greater negative impact on oral symptoms (adjusted RR = 1.11, 95%CI = 1.05–1.18) and social well-being (adjusted RR = 1.30; 95% CI = 1.14–1.47) domains than caries-free students., Conclusions: Treated caries was positively associated with OHRQoL; untreated caries and caries affecting anterior teeth were negatively associated with OHRQoL of 12-year-old Brazilian schoolchildren.

The aim of this study was to evaluate the concentrations of calcium (Ca), inorganic phosphate (Pi) and fluoride (F) in carious dentin and in different layers of sound dentin. The samples examined were 52 permanent teeth (26 sound and 26 carious), which were subjected to two experiments to assess the mineral content of: 1) two layers (internal and external) of sound dentin and 2) sound and carious dentin. Ca and Pi were analyzed using a colorimetric method with arsenazo III (C22H18As2N4O14S2) and molybdate reagents, and F was analyzed using a specific electrode. A non-parametric test, the Mann-Whitney test, was used to verify differences between groups. Sound dentin showed a higher concentration of fluoride in the internal layer than in the external layer (P = 0.03), but no inter-layer differences in Ca or Pi concentration were evident. Lower concentrations of Ca, Pi and F were observed in carious dentin than in sound dentin (P < 0.05). The results of this study suggest that the internal layer of sound dentin has a higher fluoride content than the external layer, and that carious dentin has lower concentrations of Ca, Pi and F than sound dentin.

Aim: The aim of this study was to evaluate the effectiveness of partial removal of carious dentine and restoration in a single session (PDR) and stepwise excavation (SW), both of which are treatments for deep carious lesions, in Public Health Services in Brazil., Inclusion Criteria: patients ≥6 years old, permanent molars with deep caries lesions (having a radiolucency halfway or more into dentine) and pulp vitality but absence of spontaneous pain, positive percussion test, and periapical alterations. The subjects received either PDR (test group) or SW (control group). The radiological and clinical exams were performed after a mean time of 18 months., Outcomes: success was defined as pulp sensitivity to cold test and absence of periapical alterations., Results: Of the 299 treatments performed, 146 were SW and 153 were PDR; 122 were amalgam restorations and 168 resin-composite restorations. There were no differences between the groups regarding the baseline characteristics (i.e. age, gender and family income). After 18 months, 212 evaluations were performed, which indicated 99 and 86% success rates in the PDR and SW groups, respectively (p = 0.016). Reasons for failure were: PDR - 1 pulpitis; SW - 8 pulpitis; 1 osteitis; 4 necrosis; 1 endodontic treatment. None of the baseline variables were significantly associated with the outcomes., Conclusion: The retention of carious dentine does not interfere in pulp vitality. Data from this 18-month study suggest that the procedure of reopening the cavity to remove the residual infected dentine is not necessary., (Copyright © 2012 S. Karger AG, Basel.)

This study investigated the radiographic pattern of underlying dark shadow from dentin (ICDAS 4) in permanent molars and assessed the association between enamel breakdown and radiographic features. Ninety-five teeth (54 patients) were clinically and radiographically assessed. The majority of ICDAS 4 caries lesions presented enamel breakdown (n = 78, 82.1%) and no radiographic image (n = 64, 67.4%) or a radiolucent zone restricted to the enamel-dentin junction (n = 17, 17.9%). No association was found between enamel breakdown and radiographic features. This study suggests that a radiographic examination is needed prior to the decision making process for underlying dark shadows from dentin., (Copyright © 2013 S. Karger AG, Basel.)

We evaluated the effect of calcium hydroxide cement (CHC) and glass ionomer cement (GIC) on carious dentin and bacterial infections after partial caries removal and sealing. Sixty permanent teeth with deep lesions underwent partial caries removal, the application of CHC, GIC or wax, i.e. negative control (NC), and were then sealed for 3-4 months. After the partial caries removal and the sealing period, the dentin was clinically assessed (colour and consistency) and analysed by scanning electron microscopy to assess dentin organization and bacterial infections. The effect of the treatment in each group was assessed by the Wilcoxon and χ2 tests, differences among groups by the Kruskal-Wallis test and the correlations between variables by Spearman correlation. No clinical symptoms or radiographic signals of pulpits or pulp necrosis were observed during the study. Dentin darkening was observed after the sealing period in the CHC and NC groups (p < 0.05). However, there was no difference in the colour after treatment among the 3 groups (p > 0.05). Dentin hardening occurred in all groups after treatment (p < 0.05), also with no differences (p > 0.05). Dentin samples showed better organization after the sealing period than after partial caries removal, with total or partial obliteration of dentinal tubules (CHC p < 0.03, GIC p < 0.05, NC p < 0.01) and a reduction of bacterial infections (CHC p < 0.03, GIC p < 0.05, NC p < 0.03). No differences were observed. Correlations between the different criteria, except for colour and bacterial infection, were detected in all cases. Partial caries removal and sealing resulted in dentin hardening, decreased bacterial numbers and dentin reorganization, irrespective of the dentin protection used., (Copyright © 2013 S. Karger AG, Basel.)

Background: It has been suggested that the widespread use of fluorides could interfere in the prevalence of clinically undetected occlusal dentine caries., Aim: The objective of this study was to determine the role of public water fluoridation and fluoride dentifrice on the prevalence of hidden caries in 8-10-year-old children., Design: Clinical and radiographic data on schoolchildren collected in an epidemiologic study in Porto Alegre, Brazil, at two moments, 1975 (n = 228) and 1996 (n = 213), were analysed. Only the first permanent molars were studied. Only children of the 1996 examinations had benefited from fluoridated water soon after birth and had regular access to fluoride dentifrices. The criterion applied for hidden caries, when data from 1975 to 1996 were compared, was clinical sound surfaces that presented a radiolucent zone in the dentine., Results: The prevalence of clinically sound surfaces and percentage of hidden caries was 0.51 and 26.4% in 1975 and 2.67 and 12.9% in 1996, respectively. The prevalence of hidden caries differed statistically between the two periods (P < 0.05)., Conclusions: The results do indicate that the widespread use of fluoride via public water supply and dentifrices decreases the prevalence of hidden caries., (© 2012 The Authors. International Journal of Paediatric Dentistry 2012 BSPD, IAPD and Blackwell Publishing Ltd.)

The aim of this study was to estimate the independent effects of biofilm accumulation and eruption stage on the occurrence of active caries lesions on occlusal surfaces of permanent molars. The sample consisted of 298 schoolchildren (6-15 years) who were examined by a calibrated examiner at a dental unit, using artificial light, a dental mirror and a WHO probe. The occurrence of visible biofilm on occlusal surfaces and the eruption stage of each permanent molar were recorded. After professional prophylaxis and air drying, the occlusal surfaces were classified as sound, caries-inactive or caries-active. To evaluate the association of eruption stage and biofilm accumulation with active caries lesions, a logistic regression model was used. Since data were clustered, odds ratios were obtained using generalized estimating equations with a logistic link function. 1,779 permanent molars were examined. All eruption stages were associated with active caries lesions. After adjustment for biofilm accumulation and type of molar, molars with occlusal surfaces partially exposed to the oral cavity were 63.6 times more susceptible to caries activity than molars with full occlusion (95% CI = 22.0-183.7). After adjustment for eruption stage and type of molar, teeth with a high degree of biofilm accumulation were 14.5 times more susceptible to caries activity than those without visible biofilm accumulation (95% CI = 6.5-32.4). No association between active caries and hardly detectable biofilm was found in this population. The present study found that the eruption stage of permanent molars is strongly associated with active caries lesions, adjusted for biofilm accumulation and type of molar., (Copyright © 2012 S. Karger AG, Basel.)

Objectives: The aim of this study was to compare microbiological infection after conventional carious dentine removal with incomplete carious dentine removal and sealing., Methods: Eighty-seven patients (12-50 years of age) under treatment at the Dental Clinics of the Federal University of Rio Grande do Sul (UFRGS), Brazil, participated in the study. The patients presented 90 posterior permanent teeth with primary caries. The lesions were coronal, active, and reached at least the middle third of the dentine. None of the teeth exhibited spontaneous pain, sensitivity to percussion or apical pathology (detected through radiographic exams). Pulp sensibility was confirmed by the cold test. The lesions were divided into 2 experimental groups: complete caries removal (CCR) based on hardness criteria (n=60 lesions) and incomplete caries removal (ICR) and sealing (n=32 lesions). Microbiological samples were obtained from the initial demineralized dentine, after CCR and after ICR-Seal., Results: The number of anaerobic and aerobic bacteria, lactobacilli, and mutans streptococci decreased at the end of treatment (p<0.05). Significantly less anaerobic bacteria (p<0.01), aerobic bacteria (p=0.02), and mutans streptococci (p<0.01) growth was observed after ICR-Seal compared to CCR. The difference in lactobacilli was insignificant (p=0.08). The amount of bacteria detected after conventional caries removal was higher than that which remained in sealed caries lesions., Conclusions: The results suggest it is not necessary to remove all carious dentine before the restoration is placed because over time, sealing of carious dentine results in lower levels of infection than traditional dentine caries removal., Clinical Significance: The results of this study indicate that sealed carious dentine was less infected than the remaining dentine left after conventional caries removal and sealing. Our results support treatment of deep carious lesions in one session with incomplete removal of carious dentine., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Many insects rely on the presence of symbiotic bacteria for proper immune system function. However, the molecular mechanisms that underlie this phenomenon are poorly understood. Adult tsetse flies (Glossina spp.) house three symbiotic bacteria that are vertically transmitted from mother to offspring during this insect's unique viviparous mode of reproduction. Larval tsetse that undergo intrauterine development in the absence of their obligate mutualist, Wigglesworthia, exhibit a compromised immune system during adulthood. In this study, we characterize the immune phenotype of tsetse that develop in the absence of all of their endogenous symbiotic microbes. Aposymbiotic tsetse (Glossina morsitans morsitans [Gmm(Apo)]) present a severely compromised immune system that is characterized by the absence of phagocytic hemocytes and atypical expression of immunity-related genes. Correspondingly, these flies quickly succumb to infection with normally nonpathogenic Escherichia coli. The susceptible phenotype exhibited by Gmm(Apo) adults can be reversed when they receive hemocytes transplanted from wild-type donor flies prior to infection. Furthermore, the process of immune system development can be restored in intrauterine Gmm(Apo) larvae when their mothers are fed a diet supplemented with Wigglesworthia cell extracts. Our finding that molecular components of Wigglesworthia exhibit immunostimulatory activity within tsetse is representative of a novel evolutionary adaptation that steadfastly links an obligate symbiont with its host.

Objectives: The aim of the present study was to assess Public Health Service clinicians' treatment decisions about deep carious lesions in the city of Porto Alegre, Brazil., Methods: Treatment decisions were assessed with a structured questionnaire (open/discursive and containing information about gender, university and year of college graduation, and college major) and three simulated clinical cases composed of teeth with primary deep carious lesion. All professionals working for the Public Health Service in the city were addressed., Results: Out of 122 professionals, 54 participated in the study (response rate of 44 percent). There was no difference between respondents and non-respondents regarding gender, year of college graduation, or college major. The most commonly indicated procedure was direct complete excavation (71.1 percent), followed by stepwise excavation (17.6 percent), partial caries removal (8.8 percent), and pulp therapies (direct pulp capping, partial or complete pulpotomy, and endodontics) (2.5 percent). Year of college graduation was the only variable influencing treatment decision. Logistic regression analysis showed that professionals who had graduated after the year 2000 were significantly more likely to indicate a conservative treatment than were dentists who graduated through 1979 (odds ratio = 5.5)., Conclusions: The most commonly proposed treatment is the one with the highest risk of pulp exposure, and consequently the poorest prognosis. Younger dentists tended to indicate more conservative approaches, compared with those indicated by older dentists., (© 2011 American Association of Public Health Dentistry.)

Purpose: To follow-up teeth with deep caries lesions submitted to incomplete caries removal over a 10-year period., Methods: 27 subjects (32 permanent posterior teeth) with deep caries lesions composed the sample. In this single-arm long-term prospective study, the inclusion criteria were risk of pulp exposure during caries excavation, positive response to the cold test, absence of spontaneous pain or sensitivity during percussion, and radiographic absence of a periapical lesion. Subjects were submitted to the following procedures: complete caries removal from the surrounding cavity walls, incomplete caries removal from the pulpal wall, capping with a calcium hydroxide cement, and sealing with a modified zinc oxide-eugenol cement. After 6-7 months, the temporary sealing was removed for methodological purposes (no further excavation was performed), and teeth were capped with a calcium hydroxide cement and filled with resin composite. Clinical and radiographic assessments were conducted after 6-7 months, 1.5, 3, 5 and 10 years. Success was defined as clinical and radiographic signs and symptoms of pulp sensitivity while failure was defined as endodontic treatment need., Results: Over 10 years, one tooth was excluded from the sample (pulp exposure during treatment), five were lost to recall, 10 had therapy failure (five fractures and four necroses leading to endodontic treatment need, and one extraction) and 16 had therapy success (pulp sensitivity). Overall survival rates were 97%, 90%, 82% and 63% at 1.5-, 3-, 5- and 10-year follow-ups, respectively. Teeth with two or more restored surfaces failed significantly more than teeth with one restored surface (P= 0.01).

Aim: To determine the genetic diversity and possible origin of Lactobacillus paracasei found in the oral biofilm., Methods and Results: Lactobacilli were isolated from a biofilm model, formed in situ prior to and during a period of exposure to 20% sucrose solution (28 days), using Rogosa Agar. The lactobacillus colonies were randomly selected (n = 222) and subcultured. The isolates were identified using pheS or rpoA gene sequence analysis. Lactobacilli identified as Lact. paracasei (n = 75) were subjected to multilocus sequencing typing (MLST) analysis by determining partial sequences of seven housekeeping genes fusA, ileS, lepA, leuS, pyrG, recA and recG. An increase recovery of lactobacilli after sucrose phase compared with nonsucrose period was observed (31 prior to and 191 following a sucrose exposure period). Seven subjects harboured Lact. paracasei and these represented 14 sequence types (ST). Comparison of the STs showed that unrelated subjects may harbour the same ST and that individuals harbour multiple STs. Three subjects harboured STs previously isolated from dairy products., Conclusion: The present data supports the hypothesis that oral lactobacilli may be of exogenous origin., Significance and Impact of the Study: The study allow us to gain insight into the genetic diversity of Lact. paracasei in oral biofilm., (Journal of Applied Microbiology © 2011 The Society for Applied Microbiology. No claim to Brazilian Government works.)

Unlabelled: The vast majority of bacterial species remain uncultured, and this severely limits the investigation of their physiology, metabolic capabilities, and role in the environment. High-throughput sequencing of RNA transcripts (RNA-seq) allows the investigation of the diverse physiologies from uncultured microorganisms in their natural habitat. Here, we report the use of RNA-seq for characterizing the metatranscriptome of the simple gut microbiome from the medicinal leech Hirudo verbana and for utilizing this information to design a medium for cultivating members of the microbiome. Expression data suggested that a Rikenella-like bacterium, the most abundant but uncultured symbiont, forages on sulfated- and sialated-mucin glycans that are fermented, leading to the secretion of acetate. Histological stains were consistent with the presence of sulfated and sialated mucins along the crop epithelium. The second dominant symbiont, Aeromonas veronii, grows in two different microenvironments and is predicted to utilize either acetate or carbohydrates. Based on the metatranscriptome, a medium containing mucin was designed, which enabled the cultivation of the Rikenella-like bacterium. Metatranscriptomes shed light on microbial metabolism in situ and provide critical clues for directing the culturing of uncultured microorganisms. By choosing a condition under which the desired organism is rapidly proliferating and focusing on highly expressed genes encoding hydrolytic enzymes, binding proteins, and transporters, one can identify an organism's nutritional preferences and design a culture medium., Importance: The number of prokaryotes on the planet has been estimated to exceed 10(30) cells, and the overwhelming majority of them have evaded cultivation, making it difficult to investigate their ecological, medical, and industrial relevance. The application of transcriptomics based on high-throughput sequencing of RNA transcripts (RNA-seq) to microorganisms in their natural environment can provide investigators with insight into their physiologies under optimal growth conditions. We utilized RNA-seq to learn more about the uncultured and cultured symbionts that comprise the relatively simple digestive-tract microbiome of the medicinal leech. The expression data revealed highly expressed hydrolytic enzymes and transporters that provided critical clues for the design of a culture medium enabling the isolation of the previously uncultured Rikenella-like symbiont. This directed culturing method will greatly aid efforts aimed at understanding uncultured microorganisms, including beneficial symbionts, pathogens, and ecologically relevant microorganisms, by facilitating genome sequencing, physiological characterization, and genetic manipulation of the previously uncultured microbes.

Hemolysin and the type II secretion system (T2SS) have been shown to be important for virulence in many pathogens, but very few studies have shown their importance in beneficial microbes. Here, we investigated the importance of the type II secretion pathway in the beneficial digestive-tract association of Aeromonas veronii and the medicinal leech Hirudo verbana and revealed a critical role for the hemolysis of erythrocytes. A mutant with a miniTn5 insertion in exeM, which is involved in forming the inner membrane platform in the T2SS, was isolated by screening mutants for loss of hemolysis on blood agar plates. A hemolysis assay was used to quantify the mutant's deficiency in lysing sheep erythrocytes and revealed a 99.9% decrease compared to the parent strain. The importance of the T2SS in the colonization of the symbiotic host was assessed. Colonization assays revealed that the T2SS is critical for initial colonization of the leech gut. The defect was tied to the loss of hemolysin production by performing a colonization assay with blood containing lysed erythrocytes. This restored the colonization defect in the mutant. Complementation of the mutant using the promoter region and exeMN revealed that the T2SS is responsible for secreting hemolysin into the extracellular space and that both the T2SS and hemolysin export by the T2SS are critical for initial establishment of A. veronii in the leech gut.

The effect of a combination of topical fluoridation methods for inhibition of enamel demineralization in the face of a cariogenic challenge has not been clearly established. This in situ crossover study aimed to assess whether the addition of daily use of fluoride mouthrinse (FR) to that of fluoride dentifrice (FD) is equivalent to increasing the frequency of FD application in terms of the effect on enamel demineralization and fluoride content. Over 3 phases of 14 days each, 12 volunteers wore appliances containing enamel blocks exposed to a 20 % sucrose solution 8 times/day. During each phase the blocks underwent one of the following treatments: 2x/day FD, 2x/day FD + 1x/day FR, and 3x/day FD. The blocks were assessed for hardness and fluoride content. Three x/day FD did not differ from 2x/day + 1x/day FR, however it enhanced demineralization protection when compared to 2x/day FD. All treatments produced an increase in enamel fluoride content compared to no treatment (sound blocks) (p < 0.05), but the differences between them were not significant. The results of this study suggest that the daily use of fluoride mouthrinse combined with that of fluoride dentifrice has similar effects on enamel demineralization and fluoride content when compared to increasing the frequency of fluoride dentifrice use.

Streptococcus mutans, consisting of serotypes c, e, f and k, is an oral aciduric organism associated with the initiation and progression of dental caries. A total of 135 independent Streptococcus mutans strains from caries-free and caries-active subjects isolated from various geographical locations were examined in two versions of an MLST scheme consisting of either 6 housekeeping genes [accC (acetyl-CoA carboxylase biotin carboxylase subunit), gki (glucokinase), lepA (GTP-binding protein), recP (transketolase), sodA (superoxide dismutase), and tyrS (tyrosyl-tRNA synthetase)] or the housekeeping genes supplemented with 2 extracellular putative virulence genes [gtfB (glucosyltransferase B) and spaP (surface protein antigen I/II)] to increase sequence type diversity. The number of alleles found varied between 20 (lepA) and 37 (spaP). Overall, 121 sequence types (STs) were defined using the housekeeping genes alone and 122 with all genes. However pi, nucleotide diversity per site, was low for all loci being in the range 0.019-0.007. The virulence genes exhibited the greatest nucleotide diversity and the recombination/mutation ratio was 0.67 [95% confidence interval 0.3-1.15] compared to 8.3 [95% confidence interval 5.0-14.5] for the 6 concatenated housekeeping genes alone. The ML trees generated for individual MLST loci were significantly incongruent and not significantly different from random trees. Analysis using ClonalFrame indicated that the majority of isolates were singletons and no evidence for a clonal structure or evidence to support serotype c strains as the ancestral S. mutans strain was apparent. There was also no evidence of a geographical distribution of individual isolates or that particular isolate clusters were associated with caries. The overall low sequence diversity suggests that S. mutans is a newly emerged species which has not accumulated large numbers of mutations but those that have occurred have been shuffled as a consequence of intra-species recombination generating genotypes which can be readily distinguished by sequence analysis.

Objective: The objective of this study was to assess radiographic outcomes after partial carious dentin removal performed in deep caries lesions over a 10-year period., Study Design: Baseline image was compared to 3 follow-up radiographs (at 6-7 months, 3 years, and 10 years). Tertiary dentin deposition and lesion depth were qualitatively assessed. Radiographic density changes in the radiolucent zone (RZ) beneath the restoration were quantitatively compared to the control areas (CA) using digital subtraction radiography (Friedman repeated-measures analysis of variance)., Results: A total of 13 teeth were evaluated. In most cases, lesion depth remained unchanged or decreased (12/13) and tertiary dentin formation was observed (10/13) after the 10-year follow-up. Differences between RZ and CA at the 6- to 7-month and 3-year follow-up periods were similar but significantly lower than those at the 10-year assessment., Conclusions: Sealing of carious dentin arrested the caries process, promoted deposition of tertiary dentin, and induced mineral gain in the radiolucent zone., (Copyright 2010 Mosby, Inc. All rights reserved.)

The central idea of the Brazilian health system is to prevent the establishment of disease or detect it as early as possible. Prevention and treatment of dental caries are related to behavioral factors, including dietary and oral hygiene habits, which are related to many chronic diseases. Dental health promotion therefore should be fully integrated into broadly based health-promoting strategies and actions such as food and health policies, and general hygiene (including oral hygiene), among others. For decades, a linear relationship between sugar consumption and caries has been observed. Recent data has indicated that this relationship is not as strong as it used to be before the widespread use of fluoride. However, diet is still a key factor acting in the carious process. Oral hygiene is a major aspect when it comes to caries, since dental biofilm is its etiological factor. Oral hygiene procedures are effective in controlling dental caries, especially if plaque removal is performed adequately and associated with fluoride. An alternative to a more efficient biofilm control in occlusal areas is the use of dental sealants, which are only indicated for caries-active individuals. If a cavity is formed as a consequence of the metabolic activity of the biofilm, a restorative material or a sealant can be placed to block access of the biofilm to the oral environment in order to prevent caries progress. The prevention of dental caries based on common risk-factor strategies (diet and hygiene) should be supplemented by more disease-specific policies such as rational use of fluoride, and evidence-based dental health care.

The European medicinal leech, Hirudo verbana, harbors simple microbial communities in the digestive tract and bladder. The colonization history, infection frequency, and growth dynamics of symbionts through host embryogenesis are described using diagnostic PCR and quantitative PCR. Symbiont species displayed diversity in temporal establishment and proliferation through leech development.

This literature review reports the history and the current market of oral home-care products. It provides information extending from the products used by our ancestors to those currently available, as well as on the changes in the supply and consumption of these products. Although the scientific knowledge about oral diseases has improved greatly in recent years, our ancestors had already been concerned with cleaning their teeth. A variety of rudimentary products and devices were used since before recorded history, like chewing sticks, tree twigs, bird feathers, animal bones, tooth powder and home-made mouth rinses. Today, due to technological improvements of the cosmetic industry and market competition, home-use oral care products available in the marketplace offer a great variety of options. An increase in the consumption of oral care products has been observed in the last decades. Estimates show that Latin America observed a 12% increase in hygiene and beauty products sales between 2002 and 2003, whereas the observed global rate was approximately 2%. A significant increase in the per capita consumption of toothpaste, toothbrush, mouthrinse and dental floss has been estimated from 1992 to 2002, respectively at rates of 38.3%, 138.3%, 618.8% and 177.2%. Pertaining to this increased supply and consumption of oral care products, some related questions remain unanswered, like the occurrence of changes in disease behavior due to the use of new compounds, their actual efficacy and correct indications, and the extent of the benefits to oral health derived from consuming more products.

Purpose: To evaluate in a randomized controlled study the effect of different 1% chlorhexidine (CHX) varnish regimens on levels of mutans streptococci (MS) in saliva and dental biofilm., Methods: Subjects with MS < or = 10(5) CFU/ml saliva, 11-16 years old, were allocated into four groups: Group A (n = 14): one 1% CHX varnish application; Group B (n = 14): 1% CHX varnish was applied once daily on 3 consecutive days; Group C (n = 15): 1% CHX varnish was applied three times with an interval of 4 days between each application; and Group D (n = 12): placebo varnish was applied once daily on 3 consecutive days. Saliva and dental biofilm samples were collected at baseline and 1, 4, and 8 weeks after the final varnish application., Results: After 1 week, a slight reduction in salivary levels of MS in Groups A, B, and C (-0.70, -0.90, and -0.41 log10 CFU/ml saliva, respectively) was observed, significant only in Groups A and B (P < 0.05). No difference in salivary levels of MS was observed between the experimental groups in the different experimental periods. After 1 week in the dental biofilm a significant increase in total bacterial counts was observed in all experimental groups while a significant decrease in the levels of MS was observed only in Group A.

Objectives: To evaluate whether the topical fluoride application (acidulated phosphate fluoride, APF) at high concentration has an additional effect on the control of enamel lesions compared to fluoride dentifrice (FD; low concentration). The frequency of APF treatment on the arrestment of caries lesions and the amount of fluoride deposited on enamel after application of high and low fluoride concentrations were also evaluated., Methods: Five subjects wore partial dentures with in vitro demineralized blocks during 35 days. All specimens (5p/subject) were brushed three times daily for 1 min with FD (1100 ppmF). Besides the FD treatment, four specimens were submitted to APF gel topical applications (12,300 ppmF) on weekly intervals (one to four applications). The enamel blocks were analyzed at baseline, after demineralization and after intraoral procedures regarding: surface roughness (SR), clinical aspects (brightness and texture), surface microhardness (SMH) and enamel fluoride content. Friedman's test was used to compare SMH and SR among the treatments. Analysis of variance, followed by Tukey's studentized range test, was used to evaluate fluoride content and SR among the groups. The significance level used was 5%., Results: Changes in surface brightness, texture and SR were not detected. FD+3 APF and FD+4 APF were the only treatments capable of increasing SMH values and fluoride content compared to demineralized blocks (p < 0.001), although no differences could be observed within the treatments., Conclusions: This study showed that > or = 3 APF in addition to FD enhance enamel rehardening and produce a larger reservoir of fluoride.

The aim of the present study was to evaluate the effect of two chlorhexidine rinsing solutions (0.12% and 0.2%) on plaque and gingival bleeding. Ten dental students participated in this double-blind, cross-over study, rinsing twice a day, for one minute, with each one of the tested solutions for fourteen days. A wash-out period of one week between treatments was observed. In order to assess gingival bleeding, the van der Weijden et al.(1) (1994) index was used. The plaque indexes used were those of Quigley, Hein(2) (1962) and Silness, Löe(3) (1964). In the pre-experimental period, subjects received oral hygiene instructions and dental prophylaxis. The results revealed no significant differences between both concentrations in relation to plaque and gingival bleeding. Mean values (+/- standard deviation) of the Quigley & Hein index were 0.25 +/- 0.16 for the 0.12% solution and 0.23 +/- 0.26 for the 0.2% solution (p = 0.4838). Mean values (+/- standard deviation) of the Silness-Löe index were 0.12 +/- 0.10 for the 0.12% solution and 0.11 +/- 0.11 for the 0.2% solution (p = 0.7592). The bleeding index mean values at the end of the study were not different for both concentrations with mean values (+/- standard deviation) of 14.93% +/- 6.68% and 13.95 +/- 9.24% for the 0.12% and 0.2% solutions, respectively. Although an increase in gingival bleeding was observed, both concentrations were able to control dental plaque.