RESUMEN
OBJECTIVE: Purpose of this research was to examine the onset, progression and wear rates of dental erosion in an established mouse model. MATERIAL AND METHODS: Dental erosion in mice was experimentally induced, and the acidic effects of cola drink on their teeth after 2, 4 and 6-weeks were closely analysed by scanning electron microscopy. The tooth height and enamel or dentin loss were established. Results: The dental erosion on the molars showed clear progression from 2 to 6 weeks. By the 2-week mark, a significant portion of enamel was already eroded, revealing the dentin on the lingual cusps. When adjusted for attritional wear, molars exposed to cola for 2 weeks showed a 35% drop in lingual tooth height compared to controls (533 µm vs. 818 µm). At 4 and 6 weeks, the cola-exposed group continued to display decreased lingual tooth heights by 40% (476 µm vs. 799 µm) and 43% (440 µm vs. 767 µm), respectively. CONCLUSION: This study revealed significant acidic effects of cola drink on mouse molars as early as 2 weeks. These findings highlight the challenge of monitoring dental erosion clinically and underscore the importance of early preventive and intervention measures.
Asunto(s)
Modelos Animales de Enfermedad , Progresión de la Enfermedad , Erosión de los Dientes , Animales , Erosión de los Dientes/etiología , Erosión de los Dientes/patología , Ratones , Microscopía Electrónica de Rastreo , Bebidas Gaseosas/efectos adversos , Diente Molar , Masculino , Esmalte Dental/efectos de los fármacos , Esmalte Dental/patologíaRESUMEN
Circadian rhythms are self-sustaining oscillations within biological systems that play key roles in a diverse multitude of physiological processes. The circadian clock mechanisms in brain and peripheral tissues can oscillate independently or be synchronized/disrupted by external stimuli. Dental enamel is a type of mineralized tissue that forms the exterior surface of the tooth crown. Incremental Retzius lines are readily observable microstructures of mature tooth enamel that indicate the regulation of amelogenesis by circadian rhythms. Teeth enamel is formed by enamel-forming cells known as ameloblasts, which are regulated and orchestrated by the circadian clock during amelogenesis. This review will first examine the key roles of the circadian clock in regulating ameloblasts and amelogenesis. Several physiological processes are involved, including gene expression, cell morphology, metabolic changes, matrix deposition, ion transportation, and mineralization. Next, the potential detrimental effects of circadian rhythm disruption on enamel formation are discussed. Circadian rhythm disruption can directly lead to Enamel Hypoplasia, which might also be a potential causative mechanism of amelogenesis imperfecta. Finally, future research trajectory in this field is extrapolated. It is hoped that this review will inspire more intensive research efforts and provide relevant cues in formulating novel therapeutic strategies for preventing tooth enamel developmental abnormalities.
Asunto(s)
Ameloblastos , Amelogénesis , Relojes Circadianos , Esmalte Dental , Humanos , Relojes Circadianos/fisiología , Amelogénesis/fisiología , Ameloblastos/fisiología , Animales , Ritmo Circadiano/fisiologíaRESUMEN
OBJECTIVE: The objective of this study was to evaluate the shear bond strength of metal brackets bonded with indirect bonding, under different surface treatment protocols. MATERIAL AND METHODS: 40 bovine teeth were randomly divided into four groups (n = 10), according to the type of surface treatment: G1 = 70% alcohol, G2 = air/water spray, G3 = 100-µm aluminum oxide blasting, G4 = direct boning. After drying, the standard Edgewise central incisor brackets were bonded with light-cured resin. The brackets were moved from the plaster models by means of a transfer tray made with condensation silicone, and bonded to the surface of the enamel with self-curing adhesive. The samples were submitted to shear tests by a universal test machine. Data were analyzed with SPSS 20.0 by the one-way ANOVA test and the Tukey post-test. RESULTS: No statistically significant difference (p=0.174) was observed between the mean forces measured between the group for shear strength values of the groups during the test: G1 (5.33 MPa), G2 (3.52 MPa) and G3 (4.58 MPa). CONCLUSION: The bracket surface treatment protocols presented similarities in shear bond strength test. However, alcohol 70% and oxide blasting presented higher absolute values of resistance than the water group.
Asunto(s)
Recubrimiento Dental Adhesivo , Esmalte Dental , Soportes Ortodóncicos , Resistencia al Corte , Propiedades de Superficie , Animales , Bovinos , Esmalte Dental/efectos de los fármacos , Recubrimiento Dental Adhesivo/métodos , Óxido de Aluminio/química , Análisis del Estrés Dental , Ensayo de Materiales , Cementos de Resina/química , Etanol , Agua/química , Distribución AleatoriaRESUMEN
This study aimed to evaluate chitosan (CS)-based formulations loaded with 5% sodium fluoride (NaF) and/or 10% nanohydroxyapatite (nHA) to remineralize the demineralized primary tooth enamel surface. Ninety enamel blocks were demineralized and were divided into six groups (n = 15): (1) CS-based hydrogel, (2) CS-based hydrogel loaded with NaF, (3) CS-based hydrogel loaded with nHA, (4) CS-based hydrogel loaded with NaF and nHA, (5) 5% NaF varnish, and (6) negative control with no intervention. After intervention, the specimens were pH cycled by 2 h immersion in demineralizing solution and 22 h immersion in remineralizing solution for 8 days. The remineralization effects were evaluated by Vickers microhardness measurements and field emission scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (FESEM-EDS). The best mean ± SD percentage microhardness recovery in remineralized enamel (%REMH) was found in group 4 (56.90 ± 5.49). The %REMH of groups 2 (30.74 ± 3.51) and 5 (29.23 ± 5.65) were statistically the same (p = 0.943). FESEM images confirmed partial coverage of the porous demineralized enamel with a newly formed mineralized layer. Based on EDS findings, the Ca/P ratio values of the treated enamel surfaces with CS-based hydrogels ranged between 1.71 and 1.87, and the highest F content was noticed in group 2 (1.02 ± 0.03). Although, all tested CS-based hydrogels demonstrated the potential to repair demineralized enamel, nHA- and NaF-containing CS-based hydrogel showed the highest remineralization effect. We infer that this new hybrid hydrogel is a potentially useful dental material for tooth biomineralization.
Asunto(s)
Quitosano , Esmalte Dental , Fluoruro de Sodio , Quitosano/química , Quitosano/farmacología , Fluoruro de Sodio/farmacología , Esmalte Dental/efectos de los fármacos , Esmalte Dental/química , Concentración de Iones de Hidrógeno , Humanos , Remineralización Dental/métodos , Fluoruros Tópicos/farmacología , Fluoruros Tópicos/administración & dosificación , Durapatita/química , Durapatita/farmacología , Hidrogeles/química , Biomineralización/efectos de los fármacos , Desmineralización Dental/prevención & control , Microscopía Electrónica de Rastreo , Geles/químicaRESUMEN
BACKGROUND: Understanding the role of cytokines in tooth development is critical for advancing dental tissue engineering. Fibroblast growth factor 9 (FGF9) is the only FGF consistently expressed throughout dental epithelial tissue, from the initiation of tooth bud formation to tooth maturation. However, mice lacking Fgf9 (Fgf9-/-) surprisingly show no obvious abnormalities in tooth development, suggesting potential compensation by other FGFs. Here we report findings from an Fgf9S99N mutation mouse model, a loss-of-function mutation with a dominant negative effect. Our study reveals that Fgf9 is crucial for dental epithelial stem cell (DESC) survival and enamel formation. METHODS: To dissect the role of Fgf9 in tooth development, we performed the micro-CT, histomorphological analysis and gene expression assay in mice and embryos with S99N mutation. In addition, we assessed the effect of FGF9 on the DESC survival and dental epithelial differentiation by DESC sphere formation assay and tooth explant culture. Cell/tissue culture methods, gene expression analysis, specific inhibitors, and antibody blockage analysis were employed to explore how Fgf9 regulates enamel differentiation and DESC survival through both direct and indirect mechanisms. RESULTS: The Fgf9S99N mutation in mice led to reduced ameloblasts, impaired enamel formation, and increased apoptosis in the cervical loop (CL). DESC sphere culture experiments revealed that FGF9 facilitated DESC survival via activating ERK/CREB signaling, without affecting cell proliferation. Furthermore, in vitro tissue culture experiments demonstrated that FGF9 promoted enamel formation in a manner dependent on the presence of mesenchyme. Interestingly, FGF9 stimulation inhibited enamel formation in isolated enamel epithelia and DESC spheres. Further investigation revealed that FGF9 supports DESC survival and promotes amelogenesis by stimulating the secretion of FGF3 and FGF10 in dental mesenchymal cells via the MAPK/ERK signaling pathway. CONCLUSIONS: Our study demonstrates that Fgf9 is essential for DESC survival and enamel formation. Fgf9 performs as a dual-directional regulator of the dental enamel epithelium, not only inhibiting DESC differentiation into ameloblasts to preserve the stemness of DESC, but also promoting ameloblast differentiation through epithelial-mesenchymal interactions.
Asunto(s)
Esmalte Dental , Células Epiteliales , Factor 9 de Crecimiento de Fibroblastos , Células Madre , Animales , Factor 9 de Crecimiento de Fibroblastos/metabolismo , Factor 9 de Crecimiento de Fibroblastos/genética , Ratones , Esmalte Dental/metabolismo , Células Madre/metabolismo , Células Madre/citología , Células Epiteliales/metabolismo , Incisivo/metabolismo , Supervivencia Celular , Diferenciación CelularRESUMEN
BACKGROUND: White spot lesions (WSL) are common side effects of orthodontic treatment with fixed appliances, in which the surface layer of enamel is demineralised. Thus, remineralisation, that is a partial or complete reversal, of these lesions can occur as they affect the surface enamel. Remineralisation with low-dose fluoride, in addition to optimal oral hygiene and diet, has been recommended to manage WSL. The aim of the planned trial is to assess the effectiveness of a fluoride-containing bioactive glass toothpaste (BioMin™) in its ability to remineralise post-orthodontic demineralised WSL. METHODS: A single-centre, double-blind randomised clinical trial to assess intervention with Bio-Min toothpaste on WSL forming on the teeth of young people completing orthodontic treatment. DISCUSSION: Remineralisation of WSL can vary depending on the individual and the site of the lesion. There is a range of oral fluoride delivery methods which include toothpastes, oral rinses, and gel preparations, which can aid remineralisation of these lesions. Identifying effective methods of remineralisation to manage this common and unsightly complication of fixed appliance therapy can improve the health and aesthetics of dentition. TRIAL REGISTRATION: ISRCTN.com International Standard Randomised Controlled Trials Number (ISRCTN) 14479893 . Registered on 14 May 2020.
Asunto(s)
Fluoruros , Remineralización Dental , Pastas de Dientes , Humanos , Método Doble Ciego , Remineralización Dental/métodos , Adolescente , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento , Femenino , Cariostáticos/uso terapéutico , Caries Dental/terapia , Caries Dental/prevención & control , Masculino , Esmalte Dental/efectos de los fármacos , Aparatos Ortodóncicos Fijos , NiñoRESUMEN
BACKGROUND: Tyrosine-rich amelogenin peptide (TRAP) is the main amelogenin digestion product in the developmental enamel matrix. It has been shown to promote remineralization of demineralized enamel in our previous study. However, direct evidence of the effect of TRAP on the morphology and nanostructure of crystal growth on an enamel surface has not been reported. This study aimed to examine the effect of TRAP on the morphology of calcium phosphate crystals grown on early enamel erosion using a pH-cycling model. METHODS: Eroded lesions were produced in human premolars by 30-second immersion in 37% phosphoric acid. Forty-five samples of eroded human premolar enamel blocks were selected and randomly divided into 3 groups: deionized water (DDW, negative control); 100 µg/mL TRAP, and 2 ppm sodium fluoride (NaF, positive control group). For 14 days, the specimens were exposed to a pH-cycling model. Using scanning electron microscopy (SEM) and atomic force microscopy (AFM) methods, the surface morphology, calcium-phosphorus ratio, and enamel surface roughness were examined. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to assess crystal characteristics. RESULTS: After pH-cycling, compared to the two control groups, the surface of the eroded enamel of the peptide TRAP group shows a large number of new, densely arranged rod-like crystals, parallel to each other, regularly arranged, forming an ordered structure, with crystal morphology similar to that of natural enamel. The crystals are mostly hydroxyapatite (HA). CONCLUSION: This study demonstrates that the peptide TRAP modulates the formation of hydroxyapatite in eroded enamel and that the newly formed crystals resemble natural enamel crystals and promote the remineralization of enamel, providing a promising biomaterial for remineralization treatment of enamel lesions.
Asunto(s)
Amelogenina , Esmalte Dental , Microscopía Electrónica de Rastreo , Erosión de los Dientes , Remineralización Dental , Difracción de Rayos X , Humanos , Remineralización Dental/métodos , Esmalte Dental/efectos de los fármacos , Erosión de los Dientes/patología , Concentración de Iones de Hidrógeno , Amelogenina/uso terapéutico , Amelogenina/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Microscopía de Fuerza Atómica , Fosfatos de Calcio/farmacología , Propiedades de Superficie , Diente Premolar , CristalizaciónRESUMEN
BACKGROUND: White spot lesions are a widespread undesirable effect, especially prevalent during fixed orthodontic treatments. The study compared the in vitro enamel remineralization potential of undemineralized dentin matrix (UDD) versus chicken eggshell powder (CESP) for artificially induced enamel lesions. METHODS: 100 caries-free and sound maxillary premolars were randomly divided into four groups each contain 25 teeth: Group I (Baseline): No treatment was done to the enamel surface. Group II (Negative control ): The enamel surface of the teeth underwent demineralization using demineralizing solution to create artificial carious lesions then kept in artificial saliva. Group III (CESP treated): After demineralizing the tooth surface, the teeth have been suspended in the CESP remineralizing solution. Group IV (UDD treated): After enamel demineralization, the teeth were suspended in UDD remineralizing solution. The remineralization potential was assessed by Vickers microhardness testing, scanning electron microscopic examination (SEM), and energy dispersive X-ray (EDX). RESULTS: The current study demonstrated an increase in the mean microhardness of CESP and UDD-treated groups; however, It was nearer to the baseline level in the UDD group. SEM imaging revealed greater enamel remineralization in the UDD group compared to the remaining groups. The UDD group disclosed complete coverage for the prismatic enamel compared to the CESP group, which revealed a partially remineralized enamel surface. Interestingly, the Ca/P ratio increased significantly in the CESP group compared to the negative control group. In contrast, a higher significant increase in the mean Ca/P ratios was recorded in the UDD group compared to the test groups. CONCLUSION: biomimetic UDD and CESP powder should be utilized to treat enamel early carious lesions. However, UDD demonstrated the most significant remineralization potential.
Asunto(s)
Pollos , Caries Dental , Esmalte Dental , Dentina , Cáscara de Huevo , Dureza , Microscopía Electrónica de Rastreo , Remineralización Dental , Animales , Remineralización Dental/métodos , Caries Dental/terapia , Humanos , Esmalte Dental/efectos de los fármacos , Dentina/efectos de los fármacos , Polvos , Técnicas In Vitro , Desmineralización Dental , Espectrometría por Rayos X , Diente Premolar , Saliva Artificial , Calcio/análisis , Calcio/uso terapéuticoRESUMEN
The phylogenetic relationships of the small-bodied catarrhine Pliobates cataloniae (â¼11.6 Ma, NE Iberian Peninsula) have been controversial since its original description. However, the recent report of additional dentognathic remains has supported its crouzeliid pliopithecoid status. Based on the available hypodigm, the molar enamel-dentine junction (EDJ) shape of P. cataloniae is compared with that of other pliopithecoids from the same basin as well as both extinct and extant hominoids to further evaluate its pliopithecoid affinities. We also quantitatively compare the EDJ shape among these taxa by means of landmark-based three-dimensional geometric morphometrics using principal component analysis (PCA), canonical variate analysis, and between-group PCA. Permutation tests are performed to test whether Pliobates variation exceeds that of extant hominoid genera. Results indicate that Pliobates is similar in molar EDJ shape to other pliopithecoids, particularly crouzeliids. The variation displayed by Pliobates upper molars is less marked at the EDJ level than at the outer enamel surface, probably owing to differential enamel wear and intraspecific differences in enamel thickness. Multivariate analyses of EDJ shape show that all pliopithecoids (including Pliobates) cluster together in the PCAs, canonical variate analyses, and between-group PCAs and occupy a different portion of the morphospaces from extinct and extant hominoids. Posterior and typicality probabilities strongly support the classification of Pliobates as a pliopithecoid, wheras permutation tests fail to reject the single-genus hypothesis for the P. cataloniae hypodigm. We conclude that P. cataloniae is a crouzeliid pliopithecoid, as recently supported by cladistic analyses of craniodental characters, and that previous cladistic results that supported a stem hominoid status are attributable to postcranial convergences with crown hominoids. Our results further highlight the potential of three-dimensional geometric morphometrics analyses of the EDJ shape for better informing fossil primate alpha-taxonomy by means of quantitatively testing hypotheses about tooth shape variation.
Asunto(s)
Esmalte Dental , Fósiles , Diente Molar , Animales , Diente Molar/anatomía & histología , Esmalte Dental/anatomía & histología , Fósiles/anatomía & histología , España , Dentina/anatomía & histología , Catarrinos/anatomía & histología , Catarrinos/clasificación , Análisis de Componente Principal , Filogenia , Hominidae/anatomía & histología , Hominidae/clasificaciónRESUMEN
OBJECTIVES: Dental caries result from a microbial imbalance in the oral cavity. Probiotics ecologically modulate the oral microflora to prevent caries. This study evaluated the anti-cariogenic effects of two Lacticaseibacillus rhamnosus strains in vitro and in vivo to provide a more theoretical basis for its clinical applications in caries prevention. METHODS: In the study, cariogenic biofilms were grown with L. rhamnosus (LGG) or L. rhamnosus ATCC 7469 and analyzed. Quantitative real-time PCR (qPCR), Scanning Electron Microscope (SEM), and Confocal laser scanning microscope (CLSM) were used to detect the changes in the composition and architectures; cariogenic activity was measured by the lactic acid production and Transverse Microradiography (TMR). The effects of LGG on the 12 Sprague-Dawley rat caries model were assessed using Keyes scores and micro-CT analysis. Oral microbiome changes were evaluated through 16S rRNA gene high-throughput sequencing. RESULTS: L. rhamnosus can reduce cariogenic bacteria in biofilm by 14.7 % to 48.9 %, with LGG exhibiting more potent inhibitory effects. Both strains of L. rhamnosus can adhere to the surface of biofilms, reduce the extracellular polysaccharides (EPS) matrix, and loosen the biofilm structure. L. rhamnosus inhibited cariogenic activity by reducing the lactic acid production in biofilms. The bovine enamel blocks presented lower mineral loss values and lesion depth values in the group Core+L.rh and Core+LGG. LGG-ingested rats had significantly lower levels of moderate dentin lesions and higher mineral density than the control group. The 16 s rRNA gene sequencing revealed that LGG regulated the beta diversity of the oral microbial community in the rat dental caries model. CONCLUSIONS: This study revealed the promising potential of L. rhamnosus, especially the LGG strain, in the ecological prevention of dental caries. CLINICAL SIGNIFICANCE: Probiotics may provide a strategy for preventing caries by regulating the oral microecological balance. The study revealed the promising anti-caries potential of the LGG probiotic strain in vivo and in vitro. It is expected that LGG could be used as an oral probiotic for the clinical prevention and treatment of caries.
Asunto(s)
Biopelículas , Caries Dental , Modelos Animales de Enfermedad , Lacticaseibacillus rhamnosus , Probióticos , Ratas Sprague-Dawley , Animales , Caries Dental/microbiología , Caries Dental/prevención & control , Biopelículas/efectos de los fármacos , Probióticos/uso terapéutico , Ratas , Ácido Láctico/metabolismo , ARN Ribosómico 16S , Microscopía Electrónica de Rastreo , Microtomografía por Rayos X , Esmalte Dental , Reacción en Cadena en Tiempo Real de la Polimerasa , Microbiota , Boca/microbiología , Microscopía Confocal , Microrradiografía , MasculinoRESUMEN
OBJECTIVES: In this study, we used atomic force microscopy (AFM) to quantify the size of surface pore apertures of enamel white spot lesions and then demonstrated the penetration of fluorapatite nanocrystals (nFA) into the subsurface of these lesions. METHODS: For the porosity study, enamel lesions were created on three sound human teeth using a demineralizing gel for 8 days. The interface between sound enamel and the artificial lesion was analyzed by AFM. To visualize the penetration of nFA tagged with a calcium-binding fluorophore (Fluo-4) into the subsurface of white spot lesions, we used two-photon microscopy. Sixteen extracted human teeth with either active, natural, or in vitro-created carious lesions in enamel were randomly divided into three groups. The teeth were treated for 2 min with either a suspension of tagged nFA crystals, Fluo-4 alone, or deionized water, and left for 30 min before being washed with distilled water and examined microscopically. RESULTS: A greater concentration of surface pores with larger areas was observed on the in vitro demineralized enamel (29â¯% of pores greater than 1.0 µm2) when compared with the adjacent sound enamel (8â¯% of pores greater than 1.0 µm2) (p=0.012, Fisher exact test). In vitro and natural lesions treated with tagged nFA showed fluorescence at depths ranging from 50 to 170 µm, demonstrating penetration of the nFA into the lesion subsurface. The lesions treated with Fluo-4 alone with no crystals showed mostly surface fluorescence (restricted to the outer 25 µm), while those treated with deionized water showed minimal (restricted to the outer 20 µm) to no fluorescence. CONCLUSION: We have demonstrated the use of AFM to quantify the surface pore apertures and two-photon microscopy to visualize nFA crystals in the subsurface of non-cavitated enamel lesions. CLINICAL SIGNIFICANCE: The restoration of the subsurface of non-cavitated caries lesions is a clinical challenge. This study demonstrated that a 2 min application of nFA could penetrate through the surface apertures of non-cavitated enamel lesions into their subsurface.
Asunto(s)
Apatitas , Caries Dental , Esmalte Dental , Microscopía de Fuerza Atómica , Nanopartículas , Humanos , Esmalte Dental/efectos de los fármacos , Esmalte Dental/metabolismo , Nanopartículas/química , Apatitas/química , Porosidad , Caries Dental/patología , Propiedades de Superficie , Prueba de Estudio Conceptual , Desmineralización DentalRESUMEN
OBJECTIVE: This study aims to synthesize, characterize, and assess the penetration of hydrogen peroxide (HP), color change (CC), and surface morphology changes after the application of two distinct nano-hydroxyapatite (nano-HAp). METHODS: Two nano-HAp were previously synthesized by co-precipitation: one with rod-shaped particles (RS) and the other with spherical-shaped particles (SS). The surface charge of the nano-HAp particles was determined at varying pH levels and characterized by X-ray diffraction patterns and Fourier transform infrared spectroscopy. The morphology of the samples was assessed using scanning electron microscopy (SEM). The nano-HAp particles were applied before the dental bleaching procedure. Forty teeth were divided into four groups (n = 10) according to the bleaching treatment: no treatment, bleaching with 35 % HP only, RS application and bleaching with 35 % HP, and SS application and bleaching with 35 % HP. HP concentration (µg mL-1) was measured using UV-Vis, while CC was evaluated with a digital spectrophotometer (ΔEab, ΔE00 and WID). Additionally, four teeth from each group were selected for SEM analysis. Statistical analysis encompassed one-way ANOVA, Tukey's, and Dunnet's tests. RESULTS: RS and SS were successfully synthesized by coprecipitation, primarily differing in pH during synthesis. Both variations of nano-HAp morphology significantly reduced HP diffusion into the pulp chamber (p < 0.001). Regarding enamel morphology, groups analyzed post dental bleaching exhibited greater HAp deposition on the enamel surface. Notably, this deposition did not impede CC. SIGNIFICANCE: The utilization of different nano-HAp morphologies prior to dental bleaching appears to be a promising strategy for mitigating adverse effects associated with dental bleaching procedures.
Asunto(s)
Esmalte Dental , Peróxido de Hidrógeno , Microscopía Electrónica de Rastreo , Propiedades de Superficie , Blanqueadores Dentales , Blanqueamiento de Dientes , Difracción de Rayos X , Blanqueamiento de Dientes/métodos , Esmalte Dental/efectos de los fármacos , Humanos , Blanqueadores Dentales/química , Blanqueadores Dentales/administración & dosificación , Espectroscopía Infrarroja por Transformada de Fourier , Concentración de Iones de Hidrógeno , Color , Nanopartículas/química , Hidroxiapatitas/química , Durapatita/química , Ensayo de MaterialesRESUMEN
BACKGROUND: Post-mortem toxicology constantly deals with the research of reliable alternative matrices to be applied in case of highly damaged corpses (such us carbonized, skeletonized, human remains, etc.). Teeth represent a promising alternative matrix since dental tissues are endowed by different features, resistance and stability after death. SCOPE: Since scant literature reported on the pharmacokinetics and mechanism of incorporation of xenobiotics into dental tissues, this pilot research aims to investigate whether in the pulp can be detected the same substances found in blood in drug related death cases. Secondly, the study is addressed to disclose the possible deposit of drugs in dental hard tissues (dentine and/or enamel), thus contributing to reconstruct the drug abuse history (timing, e.g.). MATERIALS AND METHODS: The study experimented with a novel method to separately analyse dental enamel, dentin, and pulp, applied to 10 teeth collected during autopsies of drug-related deaths along with blood and hair samples for classic toxicological analyses. Each tooth was prepared by "pulverization technique" and then analysed by gas chromatography paired with mass spectrometry (GC-MS) and ultra high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC/HR-MS) for searching cocaine, opiates, and metabolites. The results were then compared with those obtained from blood and hair samples. RESULTS: Preliminary results demonstrated that teeth differ from any other classic matrix (blood and hairs) since the qualitative correspondence of the detected substances between pulp and blood as well as dental hard tissues and hair suggests that they can be useful in post-mortem evaluation as a unique matrix for both acute and chronic assumptions of drugs. The mechanism of accumulation of substances in mineralized dental tissues emerged the most significant result, being influenced by the type of molecule and the method of assumption. The main limitation of this study is the limited availability of the sample and the absence of anamnestic information of the time, rates and method of drug assumption during life. Further research is necessary to systematically investigate the distribution of different substances within the different tissues of the tooth.
Asunto(s)
Esmalte Dental , Pulpa Dental , Dentina , Toxicología Forense , Cromatografía de Gases y Espectrometría de Masas , Detección de Abuso de Sustancias , Trastornos Relacionados con Sustancias , Humanos , Proyectos Piloto , Esmalte Dental/química , Dentina/química , Pulpa Dental/química , Pulpa Dental/patología , Detección de Abuso de Sustancias/métodos , Masculino , Adulto , Femenino , Toxicología Forense/métodos , Cabello/química , Persona de Mediana Edad , Narcóticos/análisis , Cocaína/análisis , Adulto Joven , Cromatografía Líquida de Alta Presión , Analgésicos Opioides/análisis , Espectrometría de MasasRESUMEN
OBJECTIVE: To investigate caries preventive effects of 38 % silver diamine fluoride (SDF) pretreatment on neighboring tooth proximal to glass ionomer cement (GIC), including conventional GIC (CGIC) and resin-modified GIC (RMGIC) restorations in an in vitro model. METHODS: HUMAN TOOTH BLOCKS WERE RESTORED WITH: SDF+CGIC (Group 1), CGIC (Group 2), SDF+RMGIC (Group 3) or RMGIC (Group 4). Enamel specimen simulating proximal surface of neighboring tooth was placed in proximity to the restorations. The specimen underwent cariogenic challenge with cross-kingdom biofilm of Streptococcus mutans, Lacticaseibacillus casei and Candida albicans. After cariogenic challenge, the biofilm's growth kinetics, viability, and morphology were evaluated by propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR), confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), respectively. The enamel lesion depth, surface morphology and crystal characteristics were determined by micro-computed tomography (micro-CT), SEM and X-ray diffraction (XRD), respectively. RESULTS: PMA-qPCR demonstrated lower microbial growth in Group 1 and 3 compared with Group 2 and 4 (p < 0.05). CLSM showed the dead-to-live ratio in Groups 1-4 were 1.15±0.12, 0.53±0.13, 1.10±0.24 and 0.63±0.10, respectively (Group 1,3 > 2,4, p < 0.05). SEM revealed Groups 1 and 3 had scattered biofilm whereas Group 2 and 4 had confluent biofilm. Micro-CT showed the enamel lesion depths (µm) were 98±9, 126±7, 103±6 and 128±7 for Group 1 to 4, respectively (Group 1,3 < 2,4, p < 0.05). SEM revealed oriented and ordered enamel prismatic patterns in Group 1 and 3, not in Group 2 and 4. XRD showed the reflections of hydroxyapatite in Groups 1 and 3 were sharper than Groups 2 and 4. CONCLUSION: SDF pretreatment enhances the preventive effect of GIC on proximal enamel surface on neighboring tooth through inhibiting cariogenic biofilm, reducing enamel demineralization and promoting enamel remineralization. CLINICAL SIGNIFICANCE: SDF pretreatment of GIC restorations can help prevent caries on neighboring teeth, particular for patients with high caries risk.
Asunto(s)
Biopelículas , Cariostáticos , Caries Dental , Esmalte Dental , Fluoruros Tópicos , Cementos de Ionómero Vítreo , Microscopía Electrónica de Rastreo , Compuestos de Amonio Cuaternario , Compuestos de Plata , Streptococcus mutans , Compuestos de Plata/uso terapéutico , Compuestos de Plata/farmacología , Humanos , Cementos de Ionómero Vítreo/uso terapéutico , Cementos de Ionómero Vítreo/farmacología , Caries Dental/prevención & control , Caries Dental/microbiología , Compuestos de Amonio Cuaternario/farmacología , Compuestos de Amonio Cuaternario/uso terapéutico , Biopelículas/efectos de los fármacos , Fluoruros Tópicos/uso terapéutico , Fluoruros Tópicos/farmacología , Cariostáticos/uso terapéutico , Cariostáticos/farmacología , Esmalte Dental/efectos de los fármacos , Streptococcus mutans/efectos de los fármacos , Restauración Dental Permanente/métodos , Microtomografía por Rayos X , Candida albicans/efectos de los fármacos , Difracción de Rayos X , Microscopía ConfocalRESUMEN
OBJECTIVES: This study assessed the effect of NaF/Chit suspensions on enamel and on S. mutans biofilm, simulating application of a mouthrinse. METHODS: The NaF/Chit particle suspensions were prepared at molar ratio [NaF]/Chitmon]≈0.68 at nominal concentrations of 0.2 % and 0.05 % NaF and characterized by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering and zeta potential. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured. The S. mutans biofilm was formed for 7 days on eighty human enamel blocks that were divided into eight groups (n = 10/group): i) 0.05 % NaF solution; ii) 0.31 % Chit solution; iii) NaF/Chit(R=0.68) suspension at 0.05 % NaF; iv) 1.0 % HAc solution (Control); v) 0.2 % NaF solution; vi) 1.25 % Chit solution; vii) NaF/Chit(R=0.68) suspension at 0.2 % NaF; viii) 0.12 % chlorhexidine digluconate. The substances were applied daily for 90 s. S. mutans cell counts (CFU/mL) were performed, and the Knoop microhardness (KHN) of enamel samples were measured before and after biofilm formation. The KHN and CFU/mL data were analyzed by repeated measure ANOVA and Tukey's test (α = 0.05). RESULTS: Interactions between NaF and Chit were evidenced in solid state by FTIR spectra. The NaF/Chit complexes showed spontaneous microparticle formation and colloidal stability. The MIC and MBC ranged from 0.65 to 1.31 mg/mL. The NaF/Chit(R=0.68) suspension at 0.2 %NaF Group showed lower CFU/mL values than other groups. The NaF/Chit(R=0.68) suspensions Groups had the highest KHN values after biofilm formation. CONCLUSIONS: The NaF/Chit(R=0.68) complexes exhibited an antibacterial effect against S. mutans biofilm and reduced the enamel hardness loss. CLINICAL SIGNIFICANCE: The NaF/Chit(R=0.68) suspensions showed potential to be used as a mouthrinse for caries prevention.
Asunto(s)
Antibacterianos , Biopelículas , Quitosano , Esmalte Dental , Pruebas de Sensibilidad Microbiana , Fluoruro de Sodio , Streptococcus mutans , Biopelículas/efectos de los fármacos , Streptococcus mutans/efectos de los fármacos , Esmalte Dental/efectos de los fármacos , Esmalte Dental/microbiología , Humanos , Antibacterianos/farmacología , Fluoruro de Sodio/farmacología , Quitosano/farmacología , Quitosano/química , Espectroscopía Infrarroja por Transformada de Fourier , Antisépticos Bucales/farmacología , Antisépticos Bucales/química , Coloides , Cariostáticos/farmacología , Cariostáticos/químicaRESUMEN
OBJECTIVE: To investigate the anticaries effects of graphene oxide (GO) and graphene quantum dots (GQDs) combined with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on enamel in a biofilm-challenged environment. MATERIAL AND METHODS: GO and GQDs were synthesised using citric acid. The antibiofilm and biofilm inhibition effects for Streptococcus mutans were evaluated by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and colony-forming units (CFU). Remineralisation ability was determined by assessing mineral loss, calcium-to-phosphorus ratio, and surface morphology. To create a biofilm-challenged environment, enamel blocks were immersed in S. mutans to create the lesion and then subjected to artificial saliva/biofilm cycling for 7 days. Anticaries effects of GO, GQDs, GQDs@CPP-ACP, GO@CPP-ACP, and CPP-ACP were determined by broth pH and mineral changes after 7-day pH cycling. Biocompatibility was tested using a Cell Counting Kit-8 (CCK8) assay for human gingival fibroblasts (HGF-1). RESULTS: GQDs and GO presented significant antibiofilm and biofilm inhibition effects compared to the CPP-ACP and control groups (P < 0.05). The enamel covered by GQDs and GO showed better crystal structure formation and less mineral loss (P < 0.05) than that covered by CPP-ACP alone. After 7 days in the biofilm-challenged environment, the GO@CPP-ACP group showed less lesion depth than the CPP-ACP and control groups (P < 0.05). GO and GQDs showed good biocompatibility compared to the control group by CCK8 (P > 0.05) within 3 days. CONCLUSION: GO and GQDs could improve the anti-caries effects of CPP-ACP, and CPP-ACP agents with GO or GQDs could be a potential option for enamel lesion management. CLINICAL SIGNIFICANCE: GO and GQDs have demonstrated the potential to significantly enhance the anticaries effects of CPP-ACP. Incorporating these nanomaterials into CPP-ACP formulations could provide innovative and effective options for the management of enamel lesions, offering improved preventive and therapeutic strategies in dental care.
Asunto(s)
Biopelículas , Caseínas , Caries Dental , Esmalte Dental , Grafito , Puntos Cuánticos , Streptococcus mutans , Grafito/química , Grafito/farmacología , Biopelículas/efectos de los fármacos , Caseínas/farmacología , Esmalte Dental/efectos de los fármacos , Streptococcus mutans/efectos de los fármacos , Humanos , Caries Dental/microbiología , Caries Dental/prevención & control , Microscopía Electrónica de Rastreo , Remineralización Dental/métodos , Cariostáticos/farmacología , Cariostáticos/química , Microscopía Confocal , Concentración de Iones de Hidrógeno , Ácido Cítrico/farmacología , Fibroblastos/efectos de los fármacos , Saliva Artificial/químicaRESUMEN
This comprehensive literature review examines the use of silver diamine fluoride (SDF) for the prevention and treatment of enamel carious lesions. SDF has been approved by different international drug associations as a caries-preventing agent to be used on deep carious lesions (dentin). However, SDF can cause staining of exposed tooth structures. Furthermore, the effect of SDF on the bond of adhesives to the tooth structure is still being determined. This review explores various studies on the use of SDF to treat enamel carious lesions, highlighting its effectiveness and preventive action. The literature suggests that SDF inhibits bacterial growth, promotes remineralization, and does not negatively affect adhesive retentions. Potassium iodide (KI) or glutathione (GSH) can reduce staining and discoloration. However, the reviewed studies have limitations. Further research, including well-designed clinical trials, is necessary to validate the findings and evaluate the long-term implications of SDF treatment. Conclusion: Despite the above-mentioned limitations, SDF shows potential as a therapy for enamel caries prevention, remineralization, and use as an adjuvant to other dental treatments, warranting further investigation and the refinement of application methods.
Asunto(s)
Cariostáticos , Caries Dental , Fluoruros Tópicos , Compuestos de Amonio Cuaternario , Compuestos de Plata , Compuestos de Plata/uso terapéutico , Humanos , Compuestos de Amonio Cuaternario/uso terapéutico , Compuestos de Amonio Cuaternario/farmacología , Caries Dental/prevención & control , Fluoruros Tópicos/uso terapéutico , Fluoruros Tópicos/administración & dosificación , Cariostáticos/uso terapéutico , Cariostáticos/farmacología , Remineralización Dental/métodos , Esmalte Dental/efectos de los fármacos , Esmalte Dental/patologíaRESUMEN
It is not clear whether different radiation methods have different effects on enamel. The purpose of this study was to compare the effects of single and fractionated radiation on enamel and caries susceptibility and to provide an experimental basis for further study of radiationrelated caries. Thirty-six caries-free human third molars were collected and randomly divided into three groups (n = 12). Group1 (control group) was not exposed to radiation. Group 2 received single radiation with a cumulative dose of 70 Gy. Group 3 underwent fractionated radiation, receiving 2 Gy/day for 5 days followed by a 2-day rest period, for a total of 7 weeks with a cumulative dose of 70 Gy. Changes in microhardness, roughness, surface morphology, bacterial adhesion and ability of acid resistance of each group were tested. Scanning electron microscope revealed that the enamel surface in both radiation groups exhibited unevenness and cracks. Compared with the control group, microhardness and acid resistance of enamel decreased, while roughness and bacterial adhesion increased in both the single radiation and fractionated radiation groups. Compared with the single radiation group, the enamel surface microhardness and acid resistance decreased in the fractionated radiation group, while roughness and bacterial adhesion increased. Both single radiation and fractionated radiation resulting in changes in the physical and biological properties of enamel, with these changes being more pronounced in the fractionated radiation group. Therefore, fractionated radiation is recommended as a more suitable method for constructing a radiationrelated caries model in vitro.
Asunto(s)
Adhesión Bacteriana , Caries Dental , Esmalte Dental , Propiedades de Superficie , Humanos , Esmalte Dental/efectos de la radiación , Esmalte Dental/microbiología , Caries Dental/microbiología , Caries Dental/patología , Adhesión Bacteriana/efectos de la radiación , Propiedades de Superficie/efectos de la radiación , Microscopía Electrónica de Rastreo , Susceptibilidad a Caries Dentarias , DurezaRESUMEN
OBJECTIVE: The present systematic review with a network meta-analysis (NMA) aimed to evaluate the effect of high-power lasers, associated or not with fluoride compounds, to control and prevent Erosive Tooth Wear (ETW). METHODS: The review was registered in the PROSPERO (CRD42021242547) and followed the PICO question: P (population): enamel and dentin substrate; I (Intervention): high-power laser irradiation, associated or not with fluoride compounds; C (Control): no-treatment; and O (Outcomes): prevention/control of ETW. The electronic databases PubMed, Scopus, and EMBASE were searched. Two independent reviewers evaluated in vitro and in situ studies. The risk of bias was assessed using the RoBDEMAT tool. The estimated treatment effect derived from direct and indirect comparisons were analyzed and the difference between these effects was calculated based on the data of enamel and dentin surface loss (in µm). RESULTS: A total of 179 studies were retrieved and after the exclusion of duplicates, 103 studies had their titles and abstracts evaluated. Thirty-nine studies had their full text analyzed for data extraction (Cohen Kappaâ¯=â¯0.88). For sound enamel, the laser irradiation (L), fluoride application (F) and, the association of treatments (Lâ¯+â¯F) promoted higher protection than No-Treatment (NT). For eroded enamel, Lâ¯+â¯F and F did not differ, but both treatments reduced surface loss compared to NT and L. For sound and eroded dentin, treatments with laser increased surface loss. CONCLUSIONS: Although a high-power laser has some potential to prevent erosive tooth wear, this effect is not better than that of standard fluoride. The use of laser in the management of dentin erosive wear can be harmful.
Asunto(s)
Fluoruros , Erosión de los Dientes , Humanos , Erosión de los Dientes/prevención & control , Metaanálisis en Red , Desgaste de los Dientes/prevención & control , Desgaste de los Dientes/etiología , Esmalte Dental/efectos de la radiación , Esmalte Dental/efectos de los fármacos , Dentina/efectos de los fármacos , Dentina/efectos de la radiación , Terapia por Luz de Baja Intensidad/métodos , Terapia por LáserRESUMEN
BACKGROUND: Patients tend to favor the whitening mouthwashes as they are easily applied and affordable. This study aimed to evaluate the effect of hydrogen peroxide versus charcoal-based whitening mouthwashes on color, surface roughness, and color stability of enamel. In the current study, the whitening mouthwashes used have the ability to stop future stains due to their white seal technology. METHODS: A total of 21 permanent central incisor teeth extracted for periodontal reasons were used in the present study. Teeth roots were sectioned and crowns were mounted in self-cured acrylic resin blocks. The specimens were randomly divided into three groups (n = 7) according to the tested whitening mouthwash: Control group ? DW" (Distilled water), ?OW" group: Peroxide-based mouthwash (Colgate Optic White) and ?CP" group: Charcoal-based mouthwash (Colgate® Plax Charcoal). Regarding ?OW" and ?CP" groups, the specimens were immersed in 20 ml of the tested mouthwash in each corresponding group for 1 min twice daily (morning and evening) for a total of 12 uninterrupted weeks. Color change was assessed using VITA Easyshade spectrophotometer and surface roughness (Ra) was measured using a white light interferometer. The specimens were stained using black tea solution and color was measured after 24 h of immersion for assessment of color stability. RESULTS: Color change results revealed that both whitening mouthwashes were able to restore color comparable to the control group with no significant difference between them. Regarding surface roughness, the control group showed the highest mean Ra value, followed by ?OW" group while ?CP" group showed the lowest mean Ra value. While color stability after staining, the control group showed a significantly higher value than the ?CP" and ?OW" groups. CONCLUSION: Hydrogen peroxide and charcoal-based whitening mouthwashes improve the color of enamel with no adverse effect on the surface roughness. Both whitening mouthwashes were beneficial to maintain the color after staining and prevent future enamel stains.