Publications - Organisation-1978-shortlist

Salivary fluoride levels after daily brushing with 5000 ppm fluoride toothpaste

Staun Larsen, L., Nyvad, B., Baelum, V. — Thu, 01 Jun 2023 15:40:30 +0200

This study explored salivary fluoride levels following toothbrushing with 5000 and 1450 ppm fluoride toothpaste and determined the decline in salivary fluoride levels following the return from 5000 to 1450 ppm fluoride toothpaste. The study was a randomised, controlled double-blind parallel clinical trial (n = 24/group) measuring salivary fluoride five times during a 3-week trial phase involving 2×/day use of 5000 or 1450 ppm fluoride toothpaste, and five times during an ensuing 2-week wash-out phase where all participants used 1450 ppm toothpaste. Salivary fluoride was measured using a fluoride electrode and data were analysed using multilevel mixed-effects linear regression. Baseline salivary fluoride geometric means were 0.014 and 0.016 ppm for the 1450 and 5000 ppm groups, while the values at the end of the trial phase were 0.023 and 0.044 ppm, respectively. During the trial phase, except at baseline, differences between groups were statistically significant. The salivary fluoride levels for the 5000 ppm group remained statistically significantly higher than for the 1450 ppm group only at the first measurement in the wash-out phase (≈30 h after the last 5000 ppm brushing), indicating that higher salivary fluoride levels resulting from use of 5000 ppm are sustained only as long as the brushing habit continues.

Effect of 5,000 ppm fluoride toothpaste on salivary fluoride: a randomized, controlled clinical trial

Staun Larsen, L., Nyvad, B., Bælum, V. — Wed, 01 Jun 2022 15:40:30 +0200

Embracing multi-causation of periodontitis

Lau, E. F., Peterson, D. E., Manzolli Leite, F. R., et al. — Sun, 01 May 2022 15:40:30 +0200

Epidemiology of Periodontal Diseases

Bælum, V., Lopez, R. — Fri, 01 Jan 2021 15:40:30 +0100

Effect of Sample Storage Conditions on Measurements of Salivary Cotinine Levels

Manzolli Leite, F. R., Bælum, V., Pajaniaye, J., Abildtrup, L. A., Lopez, R. — Wed, 01 Jan 2020 15:40:30 +0100

Abstract: Information on smoking exposure obtained with self-reports may be inaccurate. Cotinine
has a large half-life and its salivary levels correlate well with plasmatic levels. The influence of storage
conditions on the validity and precision of salivary cotinine assessments has rarely been evaluated.
Here, smokers donated saliva samples, which were sent for immediate analysis, mail posting, storage
at 4 ◦C for 30 or 90 days, or storage at −20 ◦C for 30 or 90 days. Cotinine levels were determined using
enzyme-linked immune-sorbent assay. Agreement of cotinine level measurements was assessed using
Bland-Altman analyses. Average age (years), duration of smoking (years) and number of cigarettes
smoked (/day) were 55.4 (±SD 9.4), 35.1 (±SD 11.3), and 15.3 (±SD 7.6). The mean immediate cotinine
level was 457 ng/mL (range 11.3 to 1318 ng/mL). Mean cotinine levels in samples analyzed after
delay ranged between 433 ng/mL (−20 ◦C 30 days) and 468 ng/mL (4 ◦C 30 days). A dose-response
gradient was observed in the relationship between salivary cotinine level and self-reported smoking
status. A good agreement between cotinine levels for all storage conditions compared with immediate
analysis was observed, with average differences ranging from −11 to 24 ng/mL. Cotinine levels
remained stable regardless of the tested condition. The stability of salivary cotinine may enable
samples to be obtained in difficult-to-reach areas, reduce study costs, and improve the validity of the
information on exposure to smoking.

Periodontitis phenotypes and clinical response patterns to non-surgical periodontal therapy

Nascimento, G. G., Dahlén, G., López, R., Baelum, V. — Sat, 01 Feb 2020 15:40:30 +0100

We aimed to identify response patterns to non-surgical periodontal therapy and to investigate whether the new classification system for periodontitis reflects response to treatment after 1 yr. At baseline, data on sociodemographic status, smoking, and diabetes were obtained from participants with periodontal disease. Clinical periodontal data and subgingival plaque were also collected. Participants underwent non-surgical periodontal therapy, and after 3 and 12 months, clinical data were reassessed. Factor analyses, group-based-trajectory modeling, and mixed-effects regression models were used for data analysis. Factor analysis of the baseline periodontal parameters revealed two different periodontitis dimensions: 'moderate' and 'severe'. Two response patterns for each of these periodontitis dimensions were identified. Periodontal therapy had a beneficial effect on both 'moderate' and 'severe' periodontitis; however, individuals with higher levels of disease at baseline experienced greater treatment effect. Regarding the new classification system, while the staging component distinguished different levels of 'moderate' and 'severe' periodontitis before and after treatment, the grading component did not. This study shows the beneficial effect of non-surgical periodontal therapy on both 'moderate' and 'severe' periodontitis. However, the benefit was limited among individuals with low levels of disease. The new classification system did not adequately reflect the periodontal response to therapy in this patient group.

Fluoride in Saliva and Oral Mucosa after Brushing with 1,450 or 5,000 ppm Fluoride Toothpaste

Staun Larsen, L., Baelum, V., Richards, A., Nyvad, B. — Tue, 01 Jan 2019 15:40:30 +0100

The aim was to measure and compare fluoride concentrations in oral mucosa and saliva following a single brushing with either 1,450 or 5,000 ppm fluoride toothpaste. Fourteen healthy participants provided saliva and oral mucosa samples in the morning before tooth brushing. Then participants brushed their teeth with 1,450 ppm fluoride toothpaste, and saliva and mucosa samples were collected after 1, 2, 4, and 6 h. The experiment was repeated 3–7 days later with 5,000 ppm fluoride toothpaste. All samples were analyzed for fluoride using an ion-selective electrode adapted for microanalysis. Pre-brushing fluoride concentrations were higher in mucosa (mean_1,450 0.26 ppm and mean_5,000 0.20 ppm) than in saliva (mean_1,450 0.08 ppm and mean_5,000 0.07 ppm). The mean fluoride concentrations increased in both mucosa and saliva following a single brushing with both 1,450 ppm (mean_{muc1,450 (1 h)} 1.15 ppm, mean_{sal1,450 (1 h)} 0.33 ppm) and 5,000 ppm fluoride toothpaste (mean_{muc5,000 (1 h)} 3.21 ppm and mean_{sal5,000 (1 h)} 0.90 ppm). At 6 h, the fluoride concentrations had returned to pre-brushing levels. Across the 6-h sampling period the fluoride concentration in saliva was statistically significantly 1.4 times higher following brushing with 5,000 ppm compared with 1,450 ppm fluoride toothpaste. For mucosa, this ratio was only 1.1 and not statistically significant. In conclusion, the fluoride level in oral buccal mucosa is higher than in saliva and follows the same fluoride clearance pattern as in saliva. Over the initial 6-h period following a single tooth brushing, the ratio of the fluoride concentration in mucosa to that in saliva is independent of the fluoride concentrations in the toothpastes used.

Oral hygiene phase revisited: How different study designs have affected results in intervention studies

Preus, H. R., Maharajasingam, N., Rosic, J., Bælum, V. — Tue, 01 Jan 2019 15:40:30 +0100

Every periodontal researcher have been taught, and every textbook in periodontics have advocated, that a phase in which the patient is meticulously motivated and instructed in proper oral hygiene - the oral hygiene phase - must be included in any periodontal intervention. However, how is this oral hygiene phase actually portrayed in periodontal intervention studies, and how much space have this important phase received in the planning and carry-through of intervention studies? The purpose of this letter to the editor was to review current literature in the period 1975/01/01 - 2017/12/31 on periodontal, mechanical intervention studies in order to see what focus the oral hygiene phase had received in these articles. The result showed that the oral hygiene phase is variable in length and content, variable in claimed result, insufficiently described, and invariably amalgamated with the scaling and root planing which is the intervention or part of an intervention. The consequences of these findings are discussed and suggestions proposed for more harmonized and calibrated oral hygiene phase introduced to avoid biased and inflated results of interventions. This article is protected by copyright. All rights reserved.

An IgY-based immunoassay to evaluate the biomarker potential of the Tannerella forsythia virulence factor karilysin in human saliva

Skottrup, P. D., López, R., Ksiazek, M., et al. — Tue, 01 Jan 2019 15:40:30 +0100

Tannerella forsythia is a gram-negative anaerobic bacterium that is associated with the development of destructive periodontal disease. T. forsythia secretes the metalloprotease-like enzyme karilysin. Using in vitro systems karilysin has been shown to modulate the host immune response by degradation of complement system proteins and by inactivation of the antimicrobial peptide LL-37 by proteolytic cleavage. This makes karilysin a highly interesting virulence factor to study in the framework of drug development and diagnostics. However, to date the presence of karilysin in clinical samples has not been demonstrated due to the lack of specific probes. In the present work, a high titer and stable affinity-purified avian IgY antibody against karilysin was developed. By surface plasmon resonance imaging the IgY affinity was found to be in the low nanomolar range. The antibody could be used to detect karilysin in saliva samples by immuno-blotting and was specific when tested towards human MMP-3. Furthermore, an avian IgY-based immunoassay was developed, which demonstrated low intra- and interday assay variability (CV's below 10%). Application of the immunoassay on a well-characterized set of saliva samples from adolescents with or without signs of periodontitis showed that it was possible to detect karilysin in saliva. A significant difference in karilysin concentration was found between saliva from participants with signs of periodontitis and saliva from healthy controls (p = .0024). The median of karilysin levels among periodontitis cases was 957 pg/ml (IQR, 499-2132 pg/ml) and the median for controls was 569 pg/ml (IQR, 210-1343 pg/ml). Collectively our data confirm the presence of karilysin in clinical samples. The described IgY-based immunoassay may prove useful as part of protein-based biomarker screenings in the clinic or in point-of care settings.

Salivary levels of MPO, MMP-8 and TIMP-1 are associated with gingival inflammation response patterns during experimental gingivitis.

Sun, 06 Jan 2019 15:40:30 +0100

Aim: This study aimed to investigate the association between salivary levels of myeloperoxidase (MPO), neutrophil elastase (NE), soluble urokinase-type plasminogen activator receptor (suPAR), matrix metalloproteinase (MMP)-8 and tissue inhibitor of matrix metalloproteinases (TIMP)-1 and gingival inflammation development during an experimental gingivitis study. Methods: A three-week experimental gingivitis study was conducted. Clinical recordings of dental plaque biofilm (Modified Quigley Hein Plaque Index, TQHPI) and gingival inflammation (Modified Gingival Index, MGI) were made at specific time points for each of the 42 participants. Salivary levels of MPO, NE, suPAR, MMP-8 and TIMP-1 at the same time points were measured using distinct immunoassays. For data analysis growth curve modelling was employed to account for the time-varying outcome (MGI score) and the time-varying covariates (salivary marker levels, and TQHPI score). Analyses were stratified according to the MGI-score trajectory groups previously identified as ‘fast’, respectively 'slow’ responders. Results: Overall, higher MGI scores were statistically significantly positively associated with higher levels of MPO, MMP-8 and TIMP-1. Stratified analysis according to inflammation development trajectory group revealed higher levels of salivary MPO, MMP-8 and MMP-8/TIMP-1 ratio among the ‘fast’ responders than among 'slow’ responders. None of the investigated salivary protein markers was associated with a 'slow’ inflammation development response. Conclusions: Salivary levels of MPO, MMP-8 and TIMP-1 were associated with the extent and severity of gingival inflammation. While the ‘fast’ gingival inflammation response was associated with increased levels of MPO, MMP-8 and MMP-8/TIMP-1 ratio, the 'slow’ response was not associated with any of the salivary protein markers investigated in this study. Neutrophil activity seems to orchestrate a ‘fast’ gingival inflammatory response among participants previously primed to gingival inflammation.

Pattern recognition receptor polymorphisms in early periodontitis

Leite, F. R. M., Enevold, C., Bendtzen, K., Baelum, V., López, R. — Sat, 01 Jun 2019 15:40:30 +0200

BACKGROUND: Even though bacteria trigger inflammation, most of the tissue destruction in periodontitis is due to the host inflammatory response. In addition to immunological events that drive development of early periodontitis, numerous environmental factors like genetics and smoking play a role. We investigated whether the carriage of selected single nucleotide polymorphisms (SNP) of toll-like receptors (TLR), NOD-like receptors (NLR) and RIG-I-like receptors (RLR) was associated with the diagnosis of early periodontitis in a case-control study.

METHODS: Adolescents with positive (n = 87) and negative (n = 73) diagnosis for periodontitis had blood samples taken. All participants were genotyped for 42 SNP in the genes encoding TLR1-10, NOD1-2, DDX58, and IFIH1 using multiplex assays. Associations between SNP and periodontitis diagnosis were tested.

RESULTS: TLR1-rs5743611 showed protective effect for periodontitis (CC vs. GG and GC, P = 0.01, OR 0.10, 95%CI 0.01-0.78). Carriage of the TLR4-rs7873784 was associated with higher odds for periodontitis (GG vs. CC and GC, P = 0.05, OR 2.30, 95% CI 1.00-5.63; GG vs. GC, P = 0.05, OR 2.46, 95% CI 1.01-5.99). In male participants, reduced susceptibility to periodontitis was observed in carriers of TLR7-rs3853839 (CC vs. GG and CG, P = 0.02, OR 0.30, 95% CI 0.11-0.85) and TLR8-rs3764879 (CC vs. GG and CG, P = 0.02, OR 0.31, 95% CI 0.12-0.82). Associations were maintained after adjustments for sex, smoking habits and mother´s education.

CONCLUSIONS: This study demonstrated an association between TLR1-rs5743611, TLR4-rs7873784, TLR7-rs3853839 and TLR8-rs3764879 and susceptibility to periodontitis in adolescents. This article is protected by copyright. All rights reserved.

Identification of inflammatory response patterns in experimental gingivitis studies

Nascimento, G. G., Danielsen, B., Baelum, V., Lopez, R. — Fri, 01 Feb 2019 15:40:30 +0100

We used novel analytical approaches to identify inflammatory response patterns to plaque accumulation in experimental gingivitis studies in humans. Data from two experimental gingivitis studies [Dataset I (n = 40) and Dataset II (n = 42)], which differed in design and recording methods, were used. Both studies comprised a three-phase program as follows: pre-induction period (oral hygiene as usual for Dataset I; professional tooth cleaning for Dataset II); induction period (plaque accumulation); and resolution period (oral hygiene as usual). Clinical recordings of plaque and gingival inflammation were made on days 0, 4, 9, and 14 for Dataset I and on days -14, 0, 7, 21, and 35 for Dataset II. Group-based-trajectory and growth curve modeling were used for data analysis. In Dataset I, gingival response to plaque accumulation was found to be lagged in time. Different group-based response patterns for gingival inflammation were not identified. However, in Dataset II, 'fast' and 'slow' gingival inflammation responders were identified. 'Slow' responders had lagged inflammation responses, whereas 'fast' responders seemed to respond immediately to plaque. The findings show that analytical approaches which consider the data structure allow investigation of the dynamics of the relationship between plaque accumulation and gingival inflammation and facilitate the identification of differential patterns of gingival inflammation development.

Ratiometric analysis of pH in different layers of 48-h and 120-h dental biofilms

Schlafer, S., Bælum, V., Dige, I. — Thu, 05 Jul 2018 15:40:30 +0200

Nyvad Criteria for Caries Lesion Activity and Severity Assessment: A Validated Approach for Clinical Management and Research

Nyvad, B., Bælum, V. — Mon, 05 Mar 2018 15:40:30 +0100

The Nyvad classification is a visual-tactile caries classification system devised to enable the detection of the activity and severity of caries lesions with special focus on low-caries populations. The criteria behind the classification reflect the entire continuum of caries, ranging from clinically sound surfaces through noncavitated and microcavitated caries lesions in enamel, to frank cavitation into the dentin. Lesion activity at each severity stage is discriminated by differences in surface topography and lesion texture. The reliability of the Nyvad criteria is high to excellent when used by trained examiners in the primary and permanent dentitions. The Nyvad criteria have construct validity for lesion activity assessments because of their ability to reflect the well-known caries-controlling effect of fluoride. Predictive validity was demonstrated by showing that active noncavitated lesions are at higher risk of progressing to a cavity or filled state than do inactive noncavitated lesions. Lesion activity assessment performed successfully as a screening tool to identify individuals with a poor caries prognosis. Because of their predictive validity, the Nyvad criteria are superior to other current caries lesion descriptors for the detection of changes in the lesion activity status over time. The Nyvad criteria fulfill all the formal requirements for a robust caries lesion classification and are recommended for evidence-based caries management in clinical practice and in research.

Fluoride in saliva and dental biofilm after 1,500 and 5,000 ppm fluoride exposure

Larsen, L. S., Bælum, V., Tenuta, L. M.A., Richards, A., Nyvad, B. — Sat, 08 Jul 2017 15:40:30 +0200

Fluoride in Dental Biofilm and Saliva After Use of 1,500 and 5,000 ppm Fluoride (NaF) Mouth Rinses

Larsen, L. S., Bælum, V., Tenuta, L. M.A., Richards, A., Nyvad, B. — Sun, 01 Jan 2017 15:40:30 +0100

Osteopontin adsorption to Gram-positive cells reduces adhesion forces and attachment to surfaces under flow

Kristensen, M. F., Zeng, G., Neu, T. R., Meyer, R. L., Baelum, V., Schlafer, S. — Wed, 11 Oct 2017 15:40:30 +0200

The bovine milk protein osteopontin (OPN) may be an efficient means to prevent bacterial adhesion to dental tissues and control biofilm formation. This study sought to determine to what extent OPN impacts adhesion forces and surface attachment of different bacterial strains involved in dental caries or medical device-related infections. It further investigated if OPN's effect on adhesion is caused by blocking the accessibility of glycoconjugates on bacterial surfaces. Bacterial adhesion was determined in a shear-controlled flow cell system in the presence of different concentrations of OPN, and interaction forces of single bacteria were quantified using single-cell force spectroscopy before and after OPN exposure. Moreover, the study investigated OPN's effect on the accessibility of cell surface glycoconjugates through fluorescence lectin-binding analysis. OPN strongly affected bacterial adhesion in a dose-dependent manner for all investigated species (Actinomyces naeslundii, Actinomyces viscosus, Lactobacillus paracasei subsp. paracasei, Staphylococcus epidermidis, Streptococcus mitis, and Streptococcus oralis). Likewise, adhesion forces decreased after OPN treatment. No effect of OPN on the lectin-accessibility to glycoconjugates was found. OPN reduces the adhesion and adhesion force/energy of a variety of bacteria and has a potential therapeutic use for biofilm control. OPN acts upon bacterial adhesion without blocking cell surface glycoconjugates.

Fluoride in saliva and dental biofilm after 1500 and 5000 ppm fluoride exposure

Staun Larsen, L., Baelum, V., Tenuta, L. M. A., Richards, A., Nyvad, B. — Sun, 01 Apr 2018 15:40:30 +0200

OBJECTIVES: The aim of this randomized, double-blind, crossover study was to measure fluoride in saliva and 7-day-old biofilm fluid and biofilm solids after rinsing three times per day for 3 weeks with 0, 1500, or 5000 ppm fluoride (NaF).

MATERIALS AND METHODS: Following the 3-week wash-in/wash-out period, including 1 week of biofilm accumulation, saliva and biofilm samples were collected from 12 participants immediately before (background fluoride), and 10, 30, and 60 min after a single rinse. Biofilm samples were separated into fluid and solids, and samples were analyzed using a fluoride electrode (microanalysis).

RESULTS: The background fluoride concentration was statistically significantly higher in the 5000 compared to the 1500 ppm F rinse group in all three compartments (22.3 and 8.1 μM in saliva, 126.8 and 58.5 μM in biofilm fluid, and 10,940 and 4837 μmol/kg in biofilm solids). The 1-h fluoride accumulation for the 5000 ppm F rinse was higher than for the 1500 ppm F rinse in all three compartments, although not statistically significant for saliva and biofilm solids.

CONCLUSION: Regular exposure to 5000 ppm fluoride elevates background fluoride concentrations in saliva, biofilm fluid, and biofilm solids compared to 1500 ppm fluoride. Increasing the fluoride concentration almost 3.5 times (from 1500 to 5000 ppm) only elevates the background fluoride concentrations in saliva, biofilm fluid, and biofilm solids twofold.

CLINICAL RELEVANCE: Even though fluoride toothpaste may be diluted by saliva, the results of the present study indicate that use of 5000 ppm fluoride toothpaste might lead to improved caries control.

A double-masked Randomized Clinical Trial (RCT) comparing four periodontitis treatment strategies: 5-year clinical results

Preus, H. R., Gjermo, P., Baelum, V. — Sun, 01 Oct 2017 15:40:30 +0200

AIM: To test the hypothesis of no difference in the 5-year clinical outcome of therapy between groups of patients treated with conventional over-weeks scaling and root planing or same-day full-mouth-disinfection, with or without adjunctive metronidazole.

MATERIALS AND METHODS: Following a three-month oral hygiene phase, 184 periodontitis patients were randomly allocated to one of four treatment regimens 1) full mouth disinfection+metronidazole, 2) full mouth disinfection+placebo, 3) scaling and root planing+metronidazole, 4) scaling and root planing+placebo. Following active treatment, patients received biannual maintenance. 161 patients completed the five-year follow-up maintenance and examination, where clinical attachment level, probing pocket depth, presence of plaque and bleeding were registered.

RESULTS: Metronidazole increased the highest clinical attachment level recording statistically insignificantly by an average of 0.17 mm while full mouth disinfection decreased it by an average of 0.12 mm. The corresponding values for the highest probing pocket depth were 0.00 mm and 0.05 mm, respectively.

CONCLUSION: While single-level analyses showed statistically significant differences, they could not be confirmed with more appropriate analyses, and were too small to recommend metronidazole, with its risk of patient side effects and environmental consequences, for the treatment of patients with severe periodontitis. Clinical Trials Registry number - http://www.clinicaltrials.gov - is NCT01318928.

Fluoride in dental biofilm fluid varies across regions and is higher than salivary fluoride

Staun, L., Bælum, V., Tenuta, L. M.A., Cury, J., Richards, A., Nyvad, B. — Sat, 09 Jul 2016 15:40:30 +0200

Fluoride Concentrations in Dental Biofilm Fluid Vary Across Regions and Are Higher Than in Saliva

Staun, L., Bælum, V., Tenuta, L. M.A., Cury, J., Richards, A., Nyvad, B. — Thu, 28 Apr 2016 15:40:30 +0200

A Randomized, Double-masked Clinical Trial Comparing Four Periodontitis Treatment Strategies: 5-year Tooth Loss Results

Preus, H. R., Gjermo, P., Baelum, V. — Wed, 01 Feb 2017 15:40:30 +0100

BACKGROUND: Tooth loss is the ultimate negative consequence of periodontitis, and reports of the extent to which different treatment strategies may influence the loss of teeth in the long run are hard to find.

AIM: To test the hypothesis that there is no difference in the 5-year clinical outcome of therapy in terms of tooth mortality between groups of patients treated with conventional over-weeks scaling and root planing (SRP) or same-day full-mouth disinfection (FDIS), with or without adjunctive metronidazole.

MATERIALS AND METHODS: 184 patients with moderate to severe periodontitis were randomly allocated to one of four treatment groups 1) FDIS+metronidazole, 2) FDIS+placebo, 3) SRP+metronidazole, 4) SRP+placebo. A total of 161 patients (88%) completed the five-year follow-up examination, and data on the number and timing of tooth extractions as well as the pre-extraction diagnoses and reasons for extractions, were analysed.

RESULTS: No differences were observed between groups in the number of -, reasons for - or time of extractions in the four groups at baseline, 1-, 3 - or 5 years post-treatment.

CONCLUSION: If regarding extractions, or retention of teeth, as a measure for failure or success 5 years following completion of periodontal therapy, none of the 4 strategies produced a better end result than the other.

Parodontal diagnostik efter den nye overenskomst

López, R., Kaarup-Christensen, M., Bælum, V. — Fri, 01 Jul 2016 15:40:30 +0200

Monitoring of extracellular pH in young dental biofilms grown in situ in the presence and absence of sucrose

Dige, I., Bælum, V., Nyvad, B., Schlafer, S. — Fri, 01 Jan 2016 15:40:30 +0100

pH in dental biofilms is of central importance for the development of caries. We used the ratiometric pH-sensitive dye C-SNARF-4 in combination with digital image analysis to monitor extracellular pH in dental biofilms grown in situ with and without sucrose supply. 48-h dental biofilms from 10 individuals were collected on glass slabs mounted on intra-oral appliances. During growth, appliances were immersed extra-orally in either physiological saline or 4% sucrose for 2 min eight times per day. For each individual, eight biofilm specimens were analyzed for each experiment, yielding a total of 160 biofilms. Fluorescence emissions of C-SNARF-4 in deep layers of each biofilm were recorded ex-vivo with confocal microscopy for 15 min (3 sites) or for 1 h (6 sites) after exposure to a 100 µl salivary solution with 0.4% glucose in custom-made wells. The ratiometric pH data were analyzed using a mixed-effects linear regression procedure. Extracellular pH dropped rapidly in most examined sites after addition of glucose. Distinct pH microenvironments were observed within single biofilms. Variance components analyses showed similar variation between sites within the same biofilm (var=0.02-0.04 (se=0.014-0.025)) and sites from different individuals (var=0.017-0.053 (se=0.003-0.006)). The analysis indicated similar values of all variance components between the two treatment groups. pH drop patterns did not differ significantly between biofilms exposed to sucrose-free and sucrose-rich environments (sucrose-free group: pH3-4min=6.39 (95% CI: 6.28-6.50), pH59-60min=5.63 (95% CI: 5.50-5.77); sucrose group: pH3-4min=6.38 (95% CI: 6.25-6.52); pH59-60min=5.59 (95% CI: 5.45-5.73)).The present study is the first to apply the combination of pH ratiometry and digital image analysis to systematically record extracellular pH in intact dental biofilms from several individuals for up to 1 h. We observed heterogeneous pH landscapes and the presence of highly acidogenic microenvironments within the biofilms. The data suggest that pH drops in young dental biofilm are independent of the sucrose supply during growth.

Subgingival bacterial clusters and serum antibody response as markers of extent and severity of periodontitis in adult Chinese

Dahlén, G., Luan, W., Dahlgren, U., Papapanou, P. N., Baelum, V., Fejerskov, O. — Fri, 01 Apr 2016 15:40:30 +0200

This study evaluated the associations between clinical, microbiological, and antibody activity manifestations of periodontitis in 123 adult rural Chinese subjects with no dental intervention. All participants were registered for full-mouth clinical attachment level (CAL) and pocket probing depth (PD) measurements, and microbial samples were taken from four sites and analyzed for 18 different bacterial species using the 'checkerboard'. Serum from each individual was analyzed to determine the antibody activity against the same 18 species. Exploratory factor analysis disclosed two microbial factors - Factor 1, consisting of seven species associated with periodontal health ('early colonizers'); and Factor 2, consisting of eight species associated with periodontitis ('putative periodontopathogens') - which explained 87% of the variation among the microbial variables. Factor 2 was consistently associated with disease-severity measures, whereas the 'early colonizer' factor was not. The antibody response showed weak or no correlations with bacterial load or with disease severity. We conclude that the bacteria investigated are resident in the subgingival plaque; that their load and proportions in the pocket may be ecologically driven; and that the antibody response is based on bacterial carrier state rather than on disease. The different antibody-response pattern found between the individuals may suggest that each individual could be classified as a good or a weak immune responder.

Monitoring of extracellular pH in young dental biofilms grown in vivo in the presence and absence of sucrose

Dige, I., Baelum, V., Nyvad, B., Schlafer, S. — Fri, 01 Jan 2016 15:40:30 +0100

BACKGROUND AND OBJECTIVE: pH in dental biofilms is of central importance for the development of caries. We used the ratiometric pH-sensitive dye C-SNARF-4 in combination with digital image analysis to monitor extracellular pH in dental biofilms grown in situ with and without sucrose supply.

DESIGN: Dental biofilms (48 h) from 10 individuals were collected on glass slabs mounted on intra-oral appliances. During growth, appliances were immersed extra-orally in either physiological saline or 4% sucrose for 2 min, eight times per day. Fluorescence emissions of C-SNARF-4 in deep layers of the biofilms were recorded ex vivo with confocal microscopy for 15 min or for 1 h after exposure to 0.4% glucose. Extracellular pH was determined ratiometrically using digital image analysis.

RESULTS: Extracellular pH dropped rapidly in most examined sites after addition of glucose. Distinct pH microenvironments were observed within single biofilms. The variation in pH was similar between sites within the same biofilm and sites from different individuals. pH drop patterns did not differ between biofilms exposed to sucrose-free and sucrose-rich environments.

CONCLUSION: The present study is the first of its kind to apply the combination of pH ratiometry and digital image analysis to systematically record extracellular pH in intact dental biofilms from several individuals for up to 1 h. We observed highly heterogeneous pH landscapes and the presence of acidogenic microenvironments - 'acidogenic hotspots' - within the biofilms. The data suggest that pH drops in young (48 h) dental biofilms are independent of the sucrose supply during growth.

Defining and predicting outcomes of non-surgical periodontal treatment: a 1-yr follow-up study

Baelum, V., López, R. — Mon, 01 Feb 2016 15:40:30 +0100

This study reports on 1-yr outcomes of non-surgical periodontal therapy and compares predictive models resulting from different definitions of treatment success. A total of 149 participants, 30-70 yr of age, provided clinical periodontal data and data on sociodemographic status, health status, symptoms, and oral health-care behaviors at baseline. One week later, clinical attachment level and probing pocket depth were recorded again in 148 patients. Participants underwent non-surgical periodontal therapy, including scaling and root planing, during three to four clinical sessions. Three and 12 months later, clinical attachment level, probing pocket depth, and bleeding on probing (BOP) were recorded in 141 and 137 participants, respectively. Using test-retest data, patients were classified as having 'downhill', 'stable', or 'improved' results on three clinical attachment level and three probing pocket depth outcomes, and their classification was found to vary considerably according to outcome. Although the predictors of treatment outcome varied depending on the variable chosen to represent the treatment outcome, some predictors were more commonly noted as predicting improvement, namely a high baseline percentage of sites with subgingival calculus and the presence of suppuration at baseline. The latter was, however, also predictive for tooth loss during the study. Our findings underline the need for uniformity in defining the outcomes in trials of periodontal therapy.

Editorial

Baelum, V. — Mon, 01 Feb 2016 15:40:30 +0100

Periodontal disease classifications revisited

López, R., Baelum, V. — Tue, 27 Oct 2015 15:40:30 +0100

An American Academy of Periodontology Task Force has recently published a report on the Update to the 1999 Classification of Periodontal Diseases and Conditions, which is a focused update outlining changes to be included in a comprehensive update planned for 2017. We discuss the proposed changes, and their rationales, and conclude that the periodontal classification carousel will continue to spin until it is realized that the only way forward is a profound reconsideration of what we hope to achieve with classifications.

Fluorose dentária - um manual para profissionais da Saúde

Fejerskov, O., Manji, F., Bælum, V., Møller, I. J. — Sat, 01 Jan 1994 15:40:30 +0100

Tandskader hos arbejdere på en akkumulatorfabrik

Bertram, U., Birn, H., Bollerup, J., Bælum, V. — Tue, 01 Jan 1985 15:40:30 +0100

Har de ændrede tandsygdomsmønstre i befolkningen konsekvenser for fremtidens tandpleje?

Bælum, V., Scheutz, F. — Sun, 01 Jan 1995 15:40:30 +0100

Implantatoverlevelse hos patienter med reduceret parodontium

Ellegaard, B., Bælum, V. — Thu, 01 Jan 1998 15:40:30 +0100

Implantater med sinusslimhindeløft hos parodontitispatienter. Et alternativ til friendeproteser

Ellegaard, B., Petersen, J. K., Bælum, V. — Thu, 01 Jan 1998 15:40:30 +0100

Oral Health in Uganda.

Tirwomwe, F. J., Ekoku, Y., Manji, F., Bælum, V., Fejerskov, O. — Fri, 01 Jan 1988 15:40:30 +0100

Voksentandplejen. Udredning om omfordeling af tilskuddet i voksentandplejen

Petersen, P. E. ., Holmstrup, P., Twetman, S., Karring, T., Bælum, V. — Wed, 01 Aug 2007 15:40:30 +0200

Methodological issues in the quantification of subgingival microorganisms using the checkerboard technique

Dahlen, G., Preus, H. R., Bælum, V. — Sun, 01 Mar 2015 15:40:30 +0100

The reproducibility and reliability of quantitative microbiological assessments using the DNA-DNA hybridization "checkerboard method" (CKB) were assessed. The data originated from 180 chronic periodontitis patients, who were enrolled in a clinical trial and sampled at baseline, and 3 and 12m post-therapy. The samples were divided into two portions allowing evaluation of reproducibility. In total, 531 samples were analyzed in a first run, using standard bacterial preparations of cells and 513 samples were accessible for analysis in the second, using standards based on purified DNA from the species. The microbial probe panel consisted of periodontitis marker bacteria as well as non-oral microorganisms. Three different ways of quantifying and presenting data; the visual scoring method, VSM, the standard curve method, SCM, and the percent method, PM, were compared. The second set of analyses based on the use of standard preparations of pure DNA was shown to be more consistent than the first set using standards based on cells, while the effect of storage time per se up to 2.5y seemed to be marginal. The best reproducibility was found for Tannerella forsythia, irrespective of quantification technique (Spearman's rho=0.587, Pearson's r≥0.540). The percent method (PM) based on percent of High Standard (10(6) cells) was more reliable than SCM based on a linear calibration of the High Standard and a Low Standard (10(5) cells). It was concluded that the reproducibility of the CBK method varied between different bacteria. High quality and pure specific DNA whole genomic probes and standards may have a stronger impact on the precision of the data than storage time and conditions.

A Critical Comment to the Practice of Article "Analysis and Evaluation" Faveri et al. J Evid Base Dent Pract 2014;14:70-72

Preus, H. R., Gjermo, P., Bælum, V. — Mon, 01 Jun 2015 15:40:30 +0200

Børne- og ungdomstandplejen i Hvorslev Kommune. En beskrivelse og forslag til udviklingsmuloigheder

Antoft, P., Bælum, V., Fejerskov, O., Rambusch, E. — Wed, 01 Jan 1992 15:40:30 +0100

En tand per barn - myte eller virkelighed? Kommentar til en dansk undersøgelse

Bælum, V., Scheutz, F., Poulsen, S. — Fri, 01 Jan 1999 15:40:30 +0100

Et kritisk blikk på dokumentasjonen for bruk af (Amoxicillin + Metronidazol) i periodontien

Preus, H. R., Malik, S. A., Afzal, J., Scheie, A. A. ., Bælum, V. — Wed, 01 Jan 2014 15:40:30 +0100

Changes in Prevalence an Incidence of the Major Oral Diseases

Fejerskov, O., Bælum, V. — Fri, 01 Jan 1999 15:40:30 +0100

Disease concepts and clinical decision making - some consequences for diagnosis and treatment

Bælum, V., Fejerskov, O. — Wed, 01 Jan 2003 15:40:30 +0100

Modelling data that exhibit an excess number of zeros: zero-inflated models and generic mixture models.

Gilthorpe, M. S., Frydenberg, M., Cheng, Y., Bælum, V. — Sun, 01 Jan 2012 15:40:30 +0100

How big is the problem? Epidemiological features of dental caries

Bælum, V., Fejerskov, O. — Thu, 01 Jan 2015 15:40:30 +0100

Epilogue. Controlling the global burden of dental caries: The evidence calls for a reorganization of the oral health-care system

Fejerskov, O., Bælum, V., Nyvad, B., Kidd, E. A. M. — Thu, 01 Jan 2015 15:40:30 +0100

Visual-tactile caries diagnosis

Nyvad, B., Machiulskiene, V., Soviero, V., Bælum, V. — Thu, 01 Jan 2015 15:40:30 +0100

The foundations of good diagnostic practice

Bælum, V., Nyvad, B., Gröndahl, H., Fejerskov, O. — Thu, 01 Jan 2015 15:40:30 +0100

How accurately can we assess the risk for developing caries lesions?

Hausen, H., Bælum, V. — Thu, 01 Jan 2015 15:40:30 +0100

Dose-response and dental fluorosis

Fejerskov, O., Bælum, V., Richards, A. — Mon, 01 Jan 1996 15:40:30 +0100