Monique H. van der Veen

Comparative Study to Quantify Demineralized Enamel in Deciduous and Permanent Teeth Using Laser– and Light–Induced Fluorescence Techniques

Caries is a disease that affects both deciduous and permanent dentitions. Caries progresses more rapidly in deciduous enamel than in permanent enamel. Therefore, new caries diagnostic methods need to be tested on the deciduous teeth as well. Quantitative laser–induced fluorescence (QLF I) as well as the quantitative light–induced fluorescence (QLF II) seem promising for the quantification of mineral loss from dental caries but have only been tested on the permanent dentition. The objective of this study was to determine and compare the ability of QLF I and QLF II to quantify mineral loss from carious lesions in both deciduous and permanent teeth. Thirty sound deciduous and 30 sound permanent teeth were cleaned and divided into three groups each containing 10 deciduous and 10 permanent teeth. Windows on the buccal or labial enamel surfaces were demineralized for 48, 72, or 96 h. Images of demineralized enamel were captured using QLF I and QLF II. The images were analyzed to determine the mean change in fluorescence radiance (ΔF, %). The teeth were then sectioned for assessment of lesion depth (µm) and integrated mineral loss (IML, vol% ×µm) using transverse microradiography (TMR), as the ‘gold standard’ for lesion analysis. The results indicated a good correlation for ΔF between QLF I and QLF II in both deciduous (r = 0.96) and permanent teeth (r = 0.98). There was a good correlation between ΔF and TMR (lesion depth and IML) in deciduous teeth (r = 0.76 and 0.84 with QLF I, r = 0.81 and 0.88 with QLF II). In permanent teeth, the correlation between ΔF and TMR (lesion depth and IML) was lower than in deciduous teeth (r = 0.07 and 0.53 with QLF I, r = 0.15 and 0.62 with QLF II). From these results it can be concluded that either QLF method is capable of quantifying mineral loss in early carious lesions in deciduous teeth. Moreover, under the conditions of this study, the use of either QLF method to quantify mineral loss in early carious lesions in deciduous teeth is slightly more accurate than in permanent teeth.

Quantified light-induced fluorescence, review of a diagnostic tool in prevention of oral disease

Diagnostic methods for the use in preventive dentistry are being developed continuously. Few of these find their way into general practice. Although the general trend in medicine is to focus on disease prevention and early diagnostics, in dentistry this is still not the case. Nevertheless, in dental research some of these methods seem to be promising for near future use by the general dental professional. In this paper an overview is given of a method called quantitative light-induced fluorescence or (QLF) in which visible and harmless light excites the teeth in the patients mouth to produce fluorescent images, which can be stored on disk and computer analyzed. White spots (early dental caries) are detected and quantified as well as bacterial metabolites on and in the teeth. An overview of research to validate the technique and modeling to further the understanding of the technique by Monte Carlo simulation is given and it is shown that the fluorescence phenomena can be described by the simulation model in a qualitative way. A model describing the visibility of red fluorescence from within the dental tissue is added, as this was still lacking in current literature. An overview is given of the clinical images made with the system and of the extensive research which has been done. The QLF™ technology has been shown to be of importance when used in clinical trials with respect to the testing of toothpastes and preventive treatments. It is expected that the QLF™ technology will soon find its way into the general dental practice.

Prevention and control of dental caries and periodontal diseases at individual and population level: consensus report of group 3 of joint EFP/ORCA workshop on the boundaries between caries and periodontal diseases

BACKGROUND The non-communicable diseases dental caries and periodontal diseases pose an enormous burden on mankind. The dental biofilm is a major biological determinant common to the development of both diseases, and they share common risk factors and social determinants, important for their prevention and control. The remit of this working group was to review the current state of knowledge on epidemiology, socio-behavioural aspects as well as plaque control with regard to dental caries and periodontal diseases. METHODS Discussions were informed by three systematic reviews on (i) the global burden of dental caries and periodontitis; (ii) socio-behavioural aspects in the prevention and control of dental caries and periodontal diseases at an individual and population level; and (iii) mechanical and chemical plaque control in the simultaneous management of gingivitis and dental caries. This consensus report is based on the outcomes of these systematic reviews and on expert opinion of the participants. RESULTS Key findings included the following: (i) prevalence and experience of dental caries has decreased in many regions in all age groups over the last three decades; however, not all societal groups have benefitted equally from this decline; (ii) although some studies have indicated a possible decline in periodontitis prevalence, there is insufficient evidence to conclude that prevalence has changed over recent decades; (iii) because of global population growth and increased tooth retention, the number of people affected by dental caries and periodontitis has grown substantially, increasing the total burden of these diseases globally (by 37% for untreated caries and by 67% for severe periodontitis) as estimated between 1990 and 2013, with high global economic impact; (iv) there is robust evidence for an association of low socio-economic status with a higher risk of having dental caries/caries experience and also with higher prevalence of periodontitis; (v) the most important behavioural factor, affecting both dental caries and periodontal diseases, is routinely performed oral hygiene with fluoride; (vi) population-based interventions address behavioural factors to control dental caries and periodontitis through legislation (antismoking, reduced sugar content in foods and drinks), restrictions (taxes on sugar and tobacco) guidelines and campaigns; however, their efficacy remains to be evaluated; (vii) psychological approaches aimed at changing behaviour may improve the effectiveness of oral health education; (viii) different preventive strategies have proven to be effective during the course of life; (ix) management of both dental caries and gingivitis relies heavily on efficient self-performed oral hygiene, that is toothbrushing with a fluoride-containing toothpaste and interdental cleaning; (x) professional tooth cleaning, oral hygiene instruction and motivation, dietary advice and fluoride application are effective in managing dental caries and gingivitis. CONCLUSION The prevention and control of dental caries and periodontal diseases and the prevention of ultimate tooth loss is a lifelong commitment employing population- and individual-based interventions.

Dynamics of red fluorescent dental plaque during experimental gingivitis-A cohort study

OBJECTIVES The dynamics of red fluorescent plaque (RFP) in comparison to clinical plaque and bleeding scores were studied during an experimental gingivitis protocol in a cohort of healthy participants. METHODS Forty-one participants were monitored for RFP before (24h plaque), during 14 days plaque accumulation (days 2, 5, 9, 14) and after 7 days recovery (24h plaque). RFP was assessed on fluorescence photographs of the vestibular aspect of the anterior teeth (cuspid to cuspid) in the upper and lower jaw. Clinical plaque and bleeding were assessed at days -14, 0, 14 and 21. RESULTS RFP of 24h plaque was reproducible (days -14, 0), then increased during 14 days plaque accumulation and returned to baseline after 7 days recovery. Groups of low, moderate and high RFP formers were statistically significantly different at all times even already at baseline. The individual RFP response during 14 days plaque accumulation correlated well with RFP of 24h plaque (days -14, 0). RFP correlated moderate to well with clinical plaque at days -14, 0, 14 and 21. From day 2 of the gingivitis challenge RFP correlated with bleeding at day 14. CONCLUSIONS RFP provided an objective measure of oral hygiene status. Given the correlation with clinical parameters found, the amount of RFP after 24h plaque accumulation was indicatory for the inflammatory response during a prolonged period of no oral hygiene. This trial was registered at the public trial register ​of the Central Committee on Research Involving Human Subjects (CCMO) under number NL51111.029.14 CLINICAL SIGNIFICANCE: This paper shows the association between RFP after 24h plaque accumulation and inflammatory response after a prolonged period of no oral hygiene. Red plaque fluorescence can be used to identify subjects at risk for developing gingival inflammation.

The effect of fixed orthodontic appliances and fluoride mouthwash on the oral microbiome of adolescents: a randomized controlled clinical trial

While the aesthetic effect of orthodontic treatment is clear, the knowledge on how it influences the oral microbiota and the consequential effects on oral health are limited. In this randomized controlled clinical trial we investigated the changes introduced in the oral ecosystem, during and after orthodontic treatment with fixed appliances in combination with or without a fluoride mouthwash, of 10–16.8 year old individuals (N = 91). We followed several clinical parameters in time, in combination with microbiome changes using next-generation sequencing of the bacterial 16S rRNA gene. During the course of our study, the oral microbial community displayed remarkable resilience towards the disturbances it was presented with. The effects of the fluoride mouthwash on the microbial composition were trivial. More pronounced microbial changes were related to gingival health status, orthodontic treatment and time. Periodontal pathogens (e.g. Selenomonas and Porphyromonas) were highest in abundance during the orthodontic treatment, while the health associated Streptococcus, Rothia and Haemophilus gained abundance towards the end and after the orthodontic treatment. Only minor compositional changes remained in the oral microbiome after the end of treatment. We conclude that, provided proper oral hygiene is maintained, changes in the oral microbiome composition resulting from orthodontic treatment are minimal and do not negatively affect oral health.

A prospective, randomized placebo‐controlled clinical trial on the effects of a fluoride rinse on white spot lesion development and bleeding in orthodontic patients

Demineralizations around orthodontic brackets are a main disadvantage of orthodontic treatment. Several methods have been advocated to prevent their development, such as fluoride rinses or varnishes. In this randomized clinical trial, a fluoride rinse (a combination of sodium fluoride and amine fluoride) was compared with a placebo rinse, to be used every evening after toothbrushing. A total of 81 participants (mean age: 13.3 yr) completed the study (mean treatment period: 24.5 months). Demineralizations, measured using quantitative light‐induced fluorescence and the decayed, missing, and filled surfaces (DMFS) index, were assessed before treatment (baseline) and around 6 wk after debonding (post treatment). Bleeding scores were measured at baseline, and during and post treatment. The incidence rate ratio for demineralizations was 2.6 (95% CI: 1.1–6.3) in the placebo group vs. the fluoride group. In the fluoride group, 31% of participants developed at least one demineralization, compared with 47% in the placebo group. Relative to baseline, gingival bleeding increased significantly in the placebo group 1 yr after the start of treatment and onwards. For the fluoride group, bleeding scores during treatment were not different from those at baseline. In conclusion, using a fluoride rinse helps to maintain better oral health during fixed appliance treatment, resulting in fewer demineralizations.

A Monte Carlo simulation of the influence of sound enamel scattering coefficient on lesion visibility in light-induced fluorescence

Quantitative light-induced fluorescence (QLF) is based on the dark appearance of a white spot in otherwise highly fluorescent enamel. This can be explained by the increased scattering coefficient in the white spot compared with that of sound enamel. The aim of this study was to estimate the effect of different sound enamel scattering coefficients (s_SE) and enamel thickness d, caused by developmental enamel differences, on the fluorescence appearance of white-spot lesions. We ran a Monte Carlo simulation of a 4 × 4 mm² illuminated enamel slab on a highly fluorescent background. The slab had a 0.7 × 0.7 mm², 100-µm-deep, white spot in the center. Fluorescent and back-scattered photons re-emitted from the central 2 × 2 mm² were recorded. We found that the fluorescence photon excitance from the white spot (F_WS) was less than that of sound enamel (F_SE), with an optimum difference for S_SE between 20 and 80/mm. For s_SE <20/mm, both F_SE and F_WS decreased with d. We found no relation with d for s_SE >20/mm. The results indicate that for small s_SE, we are suffering from edge losses, which explains why the optimum for lesion visibility is not found at s_SE = 0/mm, as would be expected.

Red fluorescent biofilm: the thick, the old, and the cariogenic.

Background Some dental plaque fluoresces red. The factors involved in this fluorescence are yet unknown. Objective The aim of this study was to assess systematically the effect of age, thickness, and cariogenicity on the extent of red fluorescence produced by in vitro microcosm biofilms. Design The effects of biofilm age and thickness on red fluorescence were tested in a constant depth film fermentor (CDFF) by growing biofilms of variable thicknesses that received a constant supply of defined mucin medium (DMM) and eight pulses of sucrose/day. The influence of cariogenicity on red fluorescence was tested by growing biofilm on dentin disks receiving DMM, supplemented with three or eight pulses of sucrose/day. The biofilms were analyzed at different time points after inoculation, up to 24 days. Emission spectra were measured using a fluorescence spectrophotometer (λexc405 nm) and the biofilms were photographed with a fluorescence camera. The composition of the biofilms was assessed using 454-pyrosequecing of the 16S rDNA gene. Results From day 7 onward, the biofilms emitted increasing intensities of red fluorescence as evidenced by the combined red fluorescence peaks. The red fluorescence intensity correlated with biofilm thickness but not in a linear way. Biofilm fluorescence also correlated with the imposed cariogenicity, evidenced by the induced dentin mineral loss. Increasing the biofilm age or increasing the sucrose pulsing frequency led to a shift in the microbial composition. These shifts in composition were accompanied by an increase in red fluorescence. Conclusions The current study shows that a thicker, older, or more cariogenic biofilm results in a higher intensity of red fluorescence.

Red fluorescence of dental plaque in children —A cross-sectional study

OBJECTIVES The relation between the presence of red fluorescent plaque and the caries status in children was studied. In addition, the microbial composition of dental plaque from sites with red fluorescent plaque (RFP) and from sites with no red fluorescent plaque (NFP) was assessed. METHODS Fluorescence photographs were taken from fifty children (6-14 years old) with overnight plaque. Full-mouth caries scores (ICDAS II) were obtained. The composition of a saliva sample and two plaque samples (RFP and NFP) was assessed using 16S rDNA sequencing. RESULTS At the site level, no clinically relevant correlations were found between the presence of RFP and the caries status. At the subject level, a weak correlation was found between RFP and the caries status when non-cavitated lesions were included (rs=0.37, p=0.007). The microbial composition of RFP differed significantly from NFP. RFP had more anaerobes and more Gram-negative bacterial taxa. The most discriminative operational taxonomic units (OTUs) for RFP were Corynebacterium, Leptotrichia, Porphyromonas and Selenomonas, while the most discriminative OTUs for NFP were Neisseria, Actinomyces, Streptococcus and Rothia. CONCLUSIONS There were no clinical relevant correlations in this cross-sectional study between the presence of RFP and (early) caries lesions. There were differences in the composition of these phenotypically different plaque samples: RFP contained more Gram-negative, anaerobic taxa and was more diverse than NFP. CLINICAL SIGNIFICANCE The study outcomes provide more insight in the possibilities to use plaque fluorescence in oral health risk assessments.

Microbial profile of dental plaque associated to white spot lesions in orthodontic patients immediately after the bracket removal

OBJECTIVE Denaturing Gradient Gel Electrophoresis (DGGE) is suggested to predict caries risk in young children. Such a tool would be valuable in orthodontic patients undergoing treatment with fixed appliances. In this cross-sectional study the applicability of DGGE and conventional microbiology for caries risk assessment in orthodontic patients were assessed. DESIGN Dental plaque was obtained from orthodontic patients immediately prior to bracket removal. Presence of white spot lesions (WSL) was assessed immediately post debracketing. DGGE-patterns and band counts were assessed using varying automated band detection settings and compared to visually detected bands to determine optimum settings. Optimum settings were used to compare band patterns in subjects with or without WSL. Microbiological samples were assessed for total colony forming units (CFUs) and percentages of aciduric flora, Streptococcus mutans, Lactobacillus spp. and Candida albicans. RESULTS Thirty-seven subjects were included with a mean age of 15.4yr (SD 1.6yr; 28 with WSL; 9 without WSL). Depending on settings, DGGE outcomes were different. Optimum minimum profiling absolute to the most intense band of 4% showed no significant difference in band numbers for subjects with or without WSL (p=0.845). Optimum settings for minimum profiling relative to the most intense band of 15% showed significant lower band numbers for subjects with WSL than those without (p=0.007). No differences between groups were observed for microbiological parameters. CONCLUSION The analysis of DGGE-patterns is ambiguous. Software settings significantly affected outcomes. DGGE-patterns and band numbers like CFU counts were not predictive with respect to WSL formation in these orthodontic patients.