RESUMO
The present study evaluated the effect of high-fluoride dentifrice on dentine demineralization and bacterial composition in a multispecies biofilm model in vitro. A seven-organism bacterial consortium was grown on bovine dentine discs in a high-throughput active attachment model. The biofilms were submitted twice per day to the following dentifrices treatments: 5,000 ppm F, 1,100 ppm F, with placebo as a negative control. After 5 days of biofilm growth, dentine samples were assessed by transversal microradiography, the biofilm was collected for bacterial counts and the pH of the media was determined. Lower integrated mineral loss values were observed when 5,000 ppm F-treatment was used compared to the other treatments. Overall microbiological counts decreased with increasing F-concentration as well the pH of the media throughout the experiment. The 5,000 ppm F-treatment caused a shift in microbial composition and reduced dentine demineralization in the in-vitro experimental model.
Assuntos
Dentifrícios , Desmineralização do Dente , Animais , Bactérias , Biofilmes , Cariostáticos/farmacologia , Bovinos , Dentifrícios/química , Dentifrícios/farmacologia , Dentifrícios/uso terapêutico , Dentina/microbiologia , Fluoretos/farmacologia , Desmineralização do Dente/tratamento farmacológico , Desmineralização do Dente/microbiologia , Desmineralização do Dente/prevenção & controleRESUMO
BACKGROUND: A quantitative light-induced fluorescence digital (QLF-D) camera is able to assess demineralizations adjacent to orthodontic brackets. Rotations of teeth during and the presence of the orthodontic appliances may influence the longitudinal follow-up of such lesions over time. METHODS: Brackets were bonded on extracted teeth: 54 incisors and 31 canines. Demineralizations were formed in vitro directly cervical of the bracket. Images were captured using a QLF-D camera mounted on an optical bench, equipped with a goniometer on a turntable. The teeth were placed in the goniometer simulating buccolingual rotation (0°, 10°, 20°), the turn-table was used for mesiodistal rotations (0°, 10°, 20°). Standardized QLF-D images were made before (with and without a wire) and after debonding at combinations of aforementioned angles of rotation. The image after debonding at 0° buccolingual and 0° mesiodistal rotation served as a control. RESULTS: The presence of a bracket resulted in a significantly higher fluorescence loss, yet a smaller lesion area (p < 0.05) in comparison to the control. A significant higher fluorescence loss was seen for rotations towards lingual relative to the 0° buccolingual and 0° mesiodistal rotation, while the effect was less explicit towards buccal. CONCLUSIONS: Fluorescence loss and lesion size are influenced by the angle of rotation under which the demineralization is photographed. The full extent of demineralizations is only apparent after debonding when photographed at rotations of 0° mesiodistal and up to 20° buccal. Precaution must be taken into account assessing demineralizations of patients undergoing treatment with fixed appliances when using a QLF-D camera.
Assuntos
Braquetes Ortodônticos/efeitos adversos , Descoloração de Dente/etiologia , Humanos , Técnicas In Vitro , Fotografia Dentária , Fluorescência Quantitativa Induzida por Luz/métodos , Reprodutibilidade dos Testes , Dente/patologia , Descoloração de Dente/diagnóstico , Descoloração de Dente/patologiaRESUMO
Background: Casein-phosphopeptide-amorphous-calcium-fluoride-phosphate (CPP-ACFP) can remineralize subsurface lesions. It is the active ingredient of MI-Paste-Plus® (MPP). The long-term remineralization efficacy is unknown. Objective: To evaluate the long-term effect of MPP versus a placebo paste on remineralization of enamel after fixed orthodontic treatment over a 12-month period. Design: This trial was designed as a prospective, double-blinded, placebo-controlled RCT. Methods: Patients with subsurface lesions scheduled for removal of the appliance were included. They applied either MPP or control paste once a day at bedtime for 12 months, complementary to normal oral hygiene. Main outcome measures: Changes in enamel lesions (primary outcome) were fluorescence loss and lesion area determined by quantitative light-induced fluorescence (QLF). Secondary outcomes were Microbial composition, by conventional plating, and acidogenicity of plaque, by capillary ion analysis (CIA), and lesion changes scored visually on clinical photographs. Randomization: Participants [age = 15.5 years (SD = 1.6)] were randomly assigned to either the MPP or the control group, as determined by a computer-randomization scheme, created and locked before the start of the study. Participants received neutral-coloured concealed toothpaste tubes marked A or B. Blinding: The patients and the observers were blinded with respect to the content of tube A or B. Results: A total of 51 patients were analysed; MPP (n = 25) versus control group (n = 26); data loss (n = 14). There was no significant difference between the groups over time for all the used outcome measures. There was a significant improvement in enamel lesions (fluorescence loss) over time in both groups (P < 0.001 and P < 0.001), with no differences between groups. Limitations: Being an in vivo study, non-compliance of the subjects could have influenced the result. Conclusion: The additional use of MPP in patients with subsurface enamel lesions after orthodontic fixed appliance treatment did not improve these lesions during the 1 year following debonding. Registration: This trial is registered at the medical ethical committee of the VU Medical Centre in Amsterdam (NL.199226.029.07).
Assuntos
Cariostáticos/uso terapêutico , Caseínas/uso terapêutico , Cárie Dentária/tratamento farmacológico , Aparelhos Ortodônticos Fixos/efeitos adversos , Remineralização Dentária/métodos , Adolescente , Cárie Dentária/etiologia , Esmalte Dentário/efeitos dos fármacos , Placa Dentária/tratamento farmacológico , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Cremes Dentais , Adulto JovemRESUMO
OBJECTIVES: Galla chinensis water extract (GCE) has been demonstrated to inhibit dental caries by favorably shifting the demineralization/remineralization balance of enamel and inhibiting the biomass and acid formation of dental biofilm. The present study focused on the comparison of composition and anticaries effect of Galla chinensis extracts with different isolation methods, aiming to improve the efficacy of caries prevention. METHODS: The composition of water extract (GCE), ethanol extract (eGCE) and commercial tannic acid was compared. High performance liquid chromatography coupled to electrospray ionization-time of flight-mass spectrometry (HPLC-ESI-TOF-MS) analysis was used to analyze the main ingredients. In vitro pH-cycling regime and polymicrobial biofilms model were used to assess the ability of different Galla chinensis extracts to inhibit enamel demineralization, acid formation and biofilm formation. RESULTS: All the GCE, eGCE and tannic acid contained a high level of total phenolics. HPLC-ESI-TOF-MS analysis showed that the main ingredients of GCE were gallic acid (GA), while eGCE mainly contained 4-7 galloylglucopyranoses (GGs) and tannic acid mainly contained 5-10 GGs. Furthermore, eGCE and tannic acid showed a better effect on inhibiting enamel demineralization, acid formation and biofilm formation compared to GCE. CONCLUSIONS: Galla chinensis extracts with higher tannin content were suggested to have higher potential to prevent dental caries.
RESUMO
BACKGROUND: Alkali production via arginine deiminase system (ADS) of oral bacteria plays a significant role in oral ecology, pH homeostasis and inhibition of dental caries. ADS activity in dental plaque varies greatly between individuals, which may profoundly affect their susceptibility to caries. OBJECTIVE: To investigate the effect of arginine on the growth and biofilm formation of oral bacteria. METHODS AND RESULTS: Polymicrobial dental biofilms derived from saliva were formed in a high-throughput active attachment biofilm model and l-arginine (Arg) was shown to reduce the colony forming units (CFU) counts of such biofilms grown for various periods or biofilms derived from saliva of subjects with different caries status. Arg hardly disturbed bacterial growth of Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis and Streptococcus gordonii in BHI medium, but only inhibited biofilm formation of S. mutans. Scanning electron microscope (SEM) showed S. mutans biofilms harboured fewer cells grown with Arg than that without Arg, even in the initial 2h and 8h phase. Confocal laser scanning microscope (CLSM) images of poly-microbial dental and S. mutans biofilms revealed the biofilms grown with Arg had lower exopolysaccharide (EPS)/bacteria ratios than those without Arg (P=0.004, 0.002, respectively). Arg could significantly reduce the production of water-insoluble EPS in S. mutans biofilms (P<0.001); however, quantitative real-time PCR (qRT-PCR) did not show significantly influence in gene expression of gtfB, gtfC or gtfD (P=0.32, 0.06, 0.44 respectively). CONCLUSIONS: Arg could reduce the biomass of poly-microbial dental biofilms and S. mutans biofilms, which may be due to the impact of Arg on water-insoluble EPS. Considering the contribution to pH homeostasis in dental biofilms, Arg may serve as an important agent keeping oral biofilms healthy thus prevent dental caries.
Assuntos
Arginina/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Saliva/microbiologia , Streptococcus mutans/efeitos dos fármacos , Cárie Dentária/microbiologia , Humanos , Técnicas In Vitro , Microscopia Confocal , Microscopia Eletrônica de Varredura , Reação em Cadeia da Polimerase em Tempo Real , Células-Tronco , Streptococcus gordonii/efeitos dos fármacos , Streptococcus sanguis/efeitos dos fármacos , Streptococcus sobrinus/efeitos dos fármacosRESUMO
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 (CFU's) 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.
Assuntos
Eletroforese em Gel de Gradiente Desnaturante , Placa Dentária/microbiologia , Braquetes Ortodônticos , Desmineralização do Dente/microbiologia , Adolescente , Estudos Transversais , Remoção de Dispositivo , Feminino , Humanos , Masculino , Medição de Risco , Células-TroncoRESUMO
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.
Assuntos
Bactérias/classificação , Cárie Dentária/microbiologia , Placa Dentária/microbiologia , Corantes Fluorescentes , Adolescente , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias Anaeróbias , Criança , Colorimetria/métodos , Estudos Transversais , Cárie Dentária/diagnóstico , Placa Dentária/diagnóstico , Feminino , Humanos , Masculino , Microbiota/genética , RNA Ribossômico 16S/genética , Saliva/microbiologiaRESUMO
OBJECTIVE: Bacterial metabolism of arginine in the oral cavity has a pH-raising and thus, potential anti-caries effect. However, the influence of arginine on the oral microbial ecosystem remains largely unresolved. DESIGN: In this pilot study, nine healthy individuals used toothpaste containing 8% arginine for eight weeks. Saliva was collected to determine arginolytic potential and sucrose metabolic activity at the Baseline, Week 4, Week 8 and after a two weeks Wash-out period. To follow the effects on microbial ecology, 16S rDNA sequencing on saliva and plaque samples at Baseline and Week 8 and metagenome sequencing on selected saliva samples of the same time-points was performed. RESULTS: During the study period, the arginolytic potential of saliva increased, while the sucrose metabolism in saliva decreased. These effects were reversed during the Wash-out period. Although a few operational taxonomic units (OTUs) in plaque changed in abundance during the study period, there was no real shift in the plaque microbiome. In the saliva microbiome there was a significant compositional shift, specifically the genus Veillonella had increased significantly in abundance at Week 8. CONCLUSION: Indeed, the presence of arginine in toothpaste affects the arginolytic capacity of saliva and reduces its sucrose metabolic activity. Additionally, it leads to a shift in the salivary microbiome composition towards a healthy ecology from a caries point of view. Therefore, arginine can be regarded as a genuine oral prebiotic.
Assuntos
Arginina/farmacologia , Microbiota/efeitos dos fármacos , Boca/efeitos dos fármacos , Boca/microbiologia , Cremes Dentais/farmacologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Concentração de Íons de Hidrogênio , Masculino , Projetos Piloto , RNA Ribossômico 16S/genética , Saliva/microbiologia , Análise de SequênciaRESUMO
Red and green autofluorescence have been observed from dental plaque after excitation by blue light. It has been suggested that this red fluorescence is related to caries and the cariogenic potential of dental plaque. Recently, it was suggested that red fluorescence may be related to gingivitis. Little is known about green fluorescence from biofilms. Therefore, we assessed the dynamics of red and green fluorescence in real-time during biofilm formation. In addition, the fluorescence patterns of biofilm formed from saliva of eight different donors are described under simulated gingivitis and caries conditions. Biofilm formation was analysed for 12 hours under flow conditions in a microfluidic BioFlux flow system with high performance microscopy using a camera to allow live cell imaging. For fluorescence images dedicated excitation and emission filters were used. Both green and red fluorescence were linearly related with the total biomass of the biofilms. All biofilms displayed to some extent green and red fluorescence, with higher red and green fluorescence intensities from biofilms grown in the presence of serum (gingivitis simulation) as compared to the sucrose grown biofilms (cariogenic simulation). Remarkably, cocci with long chain lengths, presumably streptococci, were observed in the biofilms. Green and red fluorescence were not found homogeneously distributed within the biofilms: highly fluorescent spots (both green and red) were visible throughout the biomass. An increase in red fluorescence from the in vitro biofilms appeared to be related to the clinical inflammatory response of the respective saliva donors, which was previously assessed during an in vivo period of performing no-oral hygiene. The BioFlux model proved to be a reliable model to assess biofilm fluorescence. With this model, a prediction can be made whether a patient will be prone to the development of gingivitis or caries.
Assuntos
Biofilmes/crescimento & desenvolvimento , Cárie Dentária/microbiologia , Placa Dentária/microbiologia , Fluorescência , Gengivite/microbiologia , Boca/microbiologia , Feminino , Humanos , Masculino , Microscopia de Fluorescência , Microscopia de Vídeo , Saliva/microbiologiaRESUMO
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.
RESUMO
OBJECTIVES: The aim of this cross-sectional study was to assess the correlation between dental plaque scores determined by the measurement of red autofluorescence or by visualization with a two-tone solution. Clinical photographs were used for this study. MATERIALS AND METHODS: Overnight plaque from the anterior teeth of 48 participants was assessed for red fluorescence on photographs (taken with a QLF-camera) using a modified Quigley & Hein (mQH) index. A two-tone disclosing solution was applied. Total disclosed plaque was clinically assessed using the mQH index. In addition, total and blue disclosed plaque was scored on clinical photographs using the mQH index. RESULTS: A strong correlation was observed between the total disclosed plaque scored on photographs and the clinical scores (r = 0.70 at site level; r = 0.88 at subject level). The correlation between red fluorescent plaque and total plaque, as assessed on the photographs, was moderate to strong and significant (r = 0.50 at the site level; r = 0.70 at the subject level), with the total plaque scores consistently higher than the red fluorescent plaque scores. The correlation between red fluorescent plaque and blue disclosed plaque was weak to moderate and significant (r = 0.30 at the site level; r = 0.50 at the subject level). CONCLUSIONS: Plaque, as scored on white-light photographs, corresponds well with clinically assessed plaque. A weak to moderate correlation between red fluorescing plaque and total disclosed plaque or blue disclosed plaque was found. CLINICAL RELEVANCE: What at present is considered to be matured dental plaque, which appears blue following the application of a two-tone disclosing solution, is not in agreement with red fluorescent dental plaque assessment.
Assuntos
Placa Dentária/diagnóstico , Corantes Fluorescentes , Fotografia Dentária/métodos , Adulto , Cor , Colorimetria/métodos , Estudos Transversais , Índice de Placa Dentária , Feminino , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
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 âof 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.
Assuntos
Índice de Placa Dentária , Placa Dentária/diagnóstico , Gengivite/diagnóstico , Adolescente , Adulto , Biofilmes/crescimento & desenvolvimento , Estudos de Coortes , Placa Dentária/diagnóstico por imagem , Feminino , Gengivite/diagnóstico por imagem , Humanos , Incisivo/patologia , Masculino , Pessoa de Meia-Idade , Higiene Bucal , Índice Periodontal , Estudos Prospectivos , Coloração e Rotulagem/métodos , Adulto JovemRESUMO
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.
Assuntos
Fluoretos/administração & dosagem , Microbiota , Boca/microbiologia , Antissépticos Bucais , Aparelhos Ortodônticos , Adolescente , Criança , Gengiva/microbiologia , Humanos , PlacebosRESUMO
Developing experimental models to understand dental caries has been the theme in our research group. Our first, the pH-cycling model, was developed to investigate the chemical reactions in enamel or dentine, which lead to dental caries. It aimed to leverage our understanding of the fluoride mode of action and was also utilized for the formulation of oral care products. In addition, we made use of intra-oral (in situ) models to study other features of the oral environment that drive the de/remineralization balance in individual patients. This model addressed basic questions, such as how enamel and dentine are affected by challenges in the oral cavity, as well as practical issues related to fluoride toothpaste efficacy. The observation that perhaps fluoride is not sufficiently potent to reduce dental caries in the present-day society triggered us to expand our knowledge in the bacterial aetiology of dental caries. For this we developed the Amsterdam Active Attachment biofilm model. Different from studies on planktonic ('single') bacteria, this biofilm model captures bacteria in a habitat similar to dental plaque. With data from the combination of these models, it should be possible to study separate processes which together may lead to dental caries. Also products and novel agents could be evaluated that interfere with either of the processes. Having these separate models in place, a suggestion is made to design computer models to encompass the available information. Models but also role models are of the utmost importance in bringing and guiding research and researchers.
Assuntos
Cárie Dentária/etiologia , Antibacterianos/uso terapêutico , Biofilmes , Cariostáticos/farmacologia , Cariostáticos/uso terapêutico , Simulação por Computador , Comportamento Cooperativo , Cárie Dentária/metabolismo , Cárie Dentária/prevenção & controle , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/metabolismo , Placa Dentária/microbiologia , Pesquisa em Odontologia , Dentina/efeitos dos fármacos , Dentina/metabolismo , Comportamento Alimentar , Fluoretos/farmacologia , Fluoretos/uso terapêutico , Humanos , Concentração de Íons de Hidrogênio , Mentores , Microbiota , Boca/microbiologia , Remineralização Dentária , Cremes Dentais/uso terapêuticoRESUMO
During the last century, dental research has focused on unraveling the mechanisms behind various oral pathologies, while oral health was typically described as the mere absence of oral diseases. The term 'oral microbial homeostasis' is used to describe the capacity of the oral ecosystem to maintain microbial community stability in health. However, the oral ecosystem itself is not stable: throughout life an individual undergoes multiple physiological changes while progressing through infancy, childhood, adolescence, adulthood and old age. Recent discussions on the definition of general health have led to the proposal that health is the ability of the individual to adapt to physiological changes, a condition known as allostasis. In this paper the allostasis principle is applied to the oral ecosystem. The multidimensionality of the host factors contributing to allostasis in the oral cavity is illustrated with an example on changes occurring in puberty. The complex phenomenon of oral health and the processes that prevent the ecosystem from collapsing during allostatic changes in the entire body are far from being understood. As yet individual components (e.g. hard tissues, microbiome, saliva, host response) have been investigated, while only by consolidating these and assessing their multidimensional interactions should we be able to obtain a comprehensive understanding of the ecosystem, which in turn could serve to develop rational schemes to maintain health. Adapting such a 'system approach' comes with major practical challenges for the entire research field and will require vast resources and large-scale multidisciplinary collaborations.
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Adaptação Fisiológica/fisiologia , Alostase/fisiologia , Saúde Bucal , Envelhecimento/fisiologia , Nível de Saúde , Homeostase/fisiologia , Humanos , Microbiota/fisiologia , Boca/microbiologia , Puberdade/fisiologiaRESUMO
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.
Assuntos
Cariostáticos/uso terapêutico , Cárie Dentária/prevenção & controle , Fluoretos/uso terapêutico , Hemorragia Gengival/prevenção & controle , Antissépticos Bucais/uso terapêutico , Braquetes Ortodônticos , Adolescente , Cariostáticos/administração & dosagem , Criança , Índice CPO , Diaminas/administração & dosagem , Diaminas/uso terapêutico , Combinação de Medicamentos , Feminino , Fluorescência , Fluoretos/administração & dosagem , Seguimentos , Humanos , Masculino , Placebos , Estudos Prospectivos , Método Simples-Cego , Fluoreto de Sódio/administração & dosagem , Fluoreto de Sódio/uso terapêutico , Escovação Dentária/métodosRESUMO
BACKGROUND: Gallic acid (GA) has been shown to inhibit demineralization and enhance remineralization of enamel; however, GA solution is highly acidic. This study was to investigate the stability of GA solutions at various pH and to examine the resultant effects on enamel demineralization. METHODS: The stability of GA in H2O or in phosphate buffer at pH 5.5, pH 7.0 and pH 10.0 was evaluated qualitatively by ultraviolet absorption spectra and quantified by high performance liquid chromatography with diode array detection (HPLC-DAD). Then, bovine enamel blocks were subjected to a pH-cycling regime of 12 cycles. Each cycle included 5 min applications with one of the following treatments: 1 g/L NaF (positive control), 4 g/L GA in H2O or buffered at pH 5.5, pH 7.0 and pH 10.0 and buffers without GA at the same pH (negative control), followed by a 60 min application with pH 5.0 acidic buffers and a 5 min application with neutral buffers. The acidic buffers were analysed for dissolved calcium. RESULTS: GA was stable in pure water and acidic condition, but was unstable in neutral and alkaline conditions, in which ultraviolet spectra changed and HPLC-DAD analysis revealed that most of the GA was degraded. All the GA groups significantly inhibited demineralization (p < 0.05) and there was no significant difference of the inhibition efficacy among different GA groups (p > 0.05). CONCLUSIONS: GA could inhibit enamel demineralization and the inhibition effect is not influenced by pH. GA could be a useful source as an anti-cariogenic agent for broad practical application.
Assuntos
Cariostáticos/uso terapêutico , Esmalte Dentário/efeitos dos fármacos , Ácido Gálico/uso terapêutico , Desmineralização do Dente/prevenção & controle , Animais , Soluções Tampão , Cálcio/análise , Bovinos , Cromatografia Líquida de Alta Pressão , Esmalte Dentário/química , Concentração de Íons de Hidrogênio , Fosfatos/química , Fluoreto de Sódio/uso terapêutico , Espectrofotometria Ultravioleta , Remineralização Dentária , Água/químicaRESUMO
OBJECTIVE: White spot lesions (WSL) are an important side-effect of orthodontic multi-bracket (MB) treatment. Standardized monitoring of such WSL may help in caries management. MATERIALS AND METHODS: In this retrospective study the discriminatory power of caries assessment on routine digital oral photographs was compared to quantitative light-induced fluorescence (QLF) imaging in monitoring WSL development after debonding of orthodontic appliances. Oral and QLF photographs captured directly after debond (T1) and 1 year thereafter (T2) of 51 subjects, treated with full MB orthodontic appliances were used. Oral photographs were assessed by use of The International Caries Detection and Assessment System (ICDAS) at both time points independently and by side-by-side comparison to assess visual transition (VT). QLF photographs were categorized based on integrated fluorescence loss at T1 and T2. RESULTS: At T1 433 and 384 lesions on 918 buccal surfaces were detected using ICDAS and QLF, respectively. For both methods these numbers were reduced at T2. Changes within ICDAS scores were recorded by VT and showed mainly lesion improvement within ICDAS score 2. CONCLUSION: The oral and QLF photographs both showed regression of WSL after debonding of MB orthodontic appliances. The VT evaluation was found to have higher discriminatory power in comparison to ICDAS.
Assuntos
Cárie Dentária/diagnóstico , Braquetes Ortodônticos , Fotografia Dentária/métodos , Adolescente , Cárie Dentária/prevenção & controle , Suscetibilidade à Cárie Dentária , Progressão da Doença , Diagnóstico Precoce , Feminino , Fluorescência , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Medição de Risco , Desmineralização do Dente/diagnóstico , Desmineralização do Dente/prevenção & controleRESUMO
Dysbiosis induced by low pH in the oral ecosystem can lead to caries, a prevalent bacterial disease in humans. The amino acid arginine is one of the pH-elevating agents in the oral cavity. To obtain insights into the effect of arginine on oral microbial ecology, a multi-plaque "artificial mouth" (MAM) biofilm model was inoculated with saliva from a healthy volunteer and microcosms were grown for 4 weeks with 1.6 % (w/v) arginine supplement (Arginine) or without (Control), samples were taken at several time-points. A cariogenic environment was mimicked by sucrose pulsing. The bacterial composition was determined by 16S rRNA gene amplicon sequencing, the presence and amount of Candida and arginine deiminase system genes arcA and sagP by qPCR. Additionally, ammonium and short-chain fatty acid concentrations were determined. The Arginine microcosms were dominated by Streptococcus, Veillonella, and Neisseria and remained stable in time, while the composition of the Control microcosms diverged significantly in time, partially due to the presence of Megasphaera. The percentage of Candida increased 100-fold in the Control microcosms compared to the Arginine microcosms. The pH-raising effect of arginine was confirmed by the pH and ammonium results. The abundances of sagP and arcA were highest in the Arginine microcosms, while the concentration of butyrate was higher in the Control microcosms. We demonstrate that supplementation with arginine serves a health-promoting function; it enhances microcosm resilience toward acidification and suppresses outgrowth of the opportunistic pathogen Candida. Arginine facilitates stability of oral microbial communities and prevents them from becoming cariogenic.
Assuntos
Arginina/farmacologia , Bactérias/efeitos dos fármacos , Candida/crescimento & desenvolvimento , Boca/microbiologia , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida/efeitos dos fármacos , DNA Bacteriano/genética , Cárie Dentária/tratamento farmacológico , Cárie Dentária/microbiologia , Genes Bacterianos , Humanos , Concentração de Íons de Hidrogênio , Hidrolases/genética , Hidrolases/metabolismo , Neisseria/efeitos dos fármacos , Neisseria/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , Saliva/microbiologia , Análise de Sequência de DNA , Streptococcus/efeitos dos fármacos , Streptococcus/crescimento & desenvolvimento , Veillonella/efeitos dos fármacos , Veillonella/crescimento & desenvolvimentoRESUMO
Tea polyphenols (TP) are not only potent antimicrobial and antioxidant agents but also effective modifiers in the formation of nanosized crystals. Since nano-hydroxyapatite (n-HA) is known to enhance remineralization of dental hard tissue, our aims were to synthesize nanosized calcium phosphate particles incorporating TP and to test their potential as caries preventive agent. An ammonia water diffusion method was used to synthesize nanosized calcium phosphate particles (TP-CaP) in the presence of various amounts of TP. The resultant products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The remineralization potential of the nano TP-CaP was then investigated in a 12-day pH-cycling model. Nano TP-CaP slurries, at pH 7.0 and pH 5.5, were applied onto preformed enamel lesions 4 × 3 min per day. n-HA slurries at pH 7.0 and pH 5.5 were used as positive controls, and deionized water was served as a negative control. SEM showed nanosized particles were only formed at 27 mg/mL of TP. Further characterization of the nanosized particles revealed the components were amorphous calcium phosphate, HA, and TP. Both surface microhardness and transverse microradiography analyses showed that nano TP-CaP at pH 5.5, but not at pH 7.0, significantly enhanced remineralization, to the same extent as the n-HA controls. Furthermore, significantly higher amount of TP was found in the supernatant of TP-CaP at pH 5.5 than those at pH 7.0. Since TP can inhibit bacterial growth and enzyme activities, the novel nanosized TP-CaP particle, at low pH, is a potential dual-functional-remineralization and antibacteria-product.