Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.507
Filtrar
1.
J Comp Pathol ; 185: 8-17, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34119235

RESUMO

Histopathological changes in tooth structures in dogs with calculus have not been described. The aim of this study was to evaluate the frequency of various histopathological changes in the dentine of teeth that had been surgically extracted from dogs with calculus. Data including breed, sex, age, reason for tooth extraction and dental history were obtained for each animal. A total of 158 teeth (45 incisors, 31 canines, 35 premolars and 47 molars) with calculus were extracted from 74 dogs of various ages and breeds. The teeth were decalcified, processed in paraffin wax and stained with haematoxylin and eosin for histopathological analysis. Of the 158 analysed teeth, 71 had dentinal changes, including 45 with external resorption cavities, 11 with osteodentine, six with internal resorption cavities, four with tertiary dentine, four with dentinal degeneration or fragmentation, and one with predentine degeneration or fragmentation. Canine teeth were the least commonly affected. Areas of dentinal degeneration or fragmentation unrelated to resorption cavities were only seen in the incisor and molar teeth. Dentinal changes and their frequencies were similar among the incisor, premolar and molar teeth. The presence or extension of dental calculus was not associated with the type or frequency of dentinal changes.


Assuntos
Cálculos Dentários , Dentina/patologia , Doenças do Cão , Dente , Animais , Cálculos Dentários/veterinária , Cães , Dente/patologia
2.
PLoS One ; 16(5): e0250429, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34038418

RESUMO

Dentin Sialoprotein (DSP) and phosphophoryn (PP) are two most dominant non-collagenous proteins in dentin, which are the cleavage products of the DSPP (dentin sialophosphoprotein) precursor protein. The absence of the DSPP gene in DSPP knock-out (KO) mice results in characteristics that are consistent with dentinogenesis imperfecta type III in humans. Symptoms include thin dentin, bigger pulp chamber with frequent pulp exposure as well as abnormal epithelial-mesenchymal interactions, and the appearance of chondrocyte-like cells in dental pulp. To better understand how DSPP influences tooth development and dentin formation, we used a bacterial artificial chromosome transgene construct (BAC-DSPP) that contained the complete DSPP gene and promoter to generate BAC-DSPP transgenic mice directly in a mouse DSPP KO background. Two BAC-DSPP transgenic mouse strains were generated and characterized. DSPP mRNA expression in BAC-DSPP Strain A incisors was similar to that from wild-type (wt) mice. DSPP mRNA expression in BAC-DSPP Strain B animals was only 10% that of wt mice. PP protein content in Strain A incisors was 25% of that found in wt mice, which was sufficient to completely rescue the DSPP KO defect in mineral density, since microCT dentin mineral density analysis in 21-day postnatal animal molars showed essentially identical mineral density in both strain A and wt mice. Strain B mouse incisors, with 5% PP expression, only partially rescued the DSPP KO defect in mineral density, as microCT scans of 21-day postnatal animal molars indicated a reduced dentin mineral density compared to wt mice, though the mineral density was still increased over that of DSPP KO. Furthermore, our findings showed that DSPP dosage in Strain A was sufficient to rescue the DSPP KO defect in terms of epithelial-mesenchymal interactions, odontoblast lineage maintenance, along with normal dentin thickness and normal mineral density while DSPP gene dosage in Strain B only partially rescued the aforementioned DSPP KO defect.


Assuntos
Dentina/metabolismo , Proteínas da Matriz Extracelular/genética , Fosfoproteínas/genética , Sialoglicoproteínas/genética , Dente/crescimento & desenvolvimento , Animais , Cromossomos Artificiais Bacterianos/genética , Colágeno Tipo II , Dentina/diagnóstico por imagem , Dentina/patologia , Proteínas da Matriz Extracelular/deficiência , Proteínas da Matriz Extracelular/metabolismo , Incisivo/metabolismo , Incisivo/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Minerais/análise , Fosfoproteínas/deficiência , Fosfoproteínas/metabolismo , RNA Mensageiro/metabolismo , Sialoglicoproteínas/deficiência , Sialoglicoproteínas/metabolismo , Dente/metabolismo , Microtomografia por Raio-X
3.
Sci Rep ; 11(1): 6083, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727650

RESUMO

This in vitro study evaluated the protective effect of titanium tetrafluoride (TiF4) varnish and silver diamine fluoride (SDF) solution on the radiation-induced dentin caries. Bovine root dentin samples were irradiated (70 Gy) and treated as follows: (6 h): 4% TiF4 varnish; 5.42% NaF varnish; 30% SDF solution; placebo varnish; or untreated (negative control). Microcosm biofilm was produced from human dental biofilm (from patients with head-neck cancer) mixed with McBain saliva for the first 8 h. After 16 h and from day 2 to day 5, McBain saliva (0.2% sucrose) was replaced daily (37 °C, 5% CO2) (biological triplicate). Demineralization was quantified by transverse microradiography (TMR), while biofilm was analyzed by using viability, colony-forming units (CFU) counting and lactic acid production assays. The data were statistically analyzed by ANOVA (p < 0.05). TiF4 and SDF were able to reduce mineral loss compared to placebo and the negative control. TiF4 and SDF significantly reduced the biofilm viability compared to negative control. TiF4 significantly reduced the CFU count of total microorganism, while only SDF affected total streptococci and mutans streptococci counts. The varnishes induced a reduction in lactic acid production compared to the negative control. TiF4 and SDF may be good alternatives to control the development of radiation-induced dentin caries.


Assuntos
Cárie Dentária , Dentina , Compostos de Amônio Quaternário/farmacologia , Lesões Experimentais por Radiação , Protetores contra Radiação/farmacologia , Compostos de Prata/farmacologia , Titânio/farmacologia , Raios X/efeitos adversos , Animais , Bovinos , Cárie Dentária/metabolismo , Cárie Dentária/patologia , Cárie Dentária/prevenção & controle , Dentina/metabolismo , Dentina/patologia , Fluoretos Tópicos/farmacologia , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/prevenção & controle
4.
Am J Phys Anthropol ; 174(1): 20-34, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33017861

RESUMO

OBJECTIVES: To study pre- and early postnatal tooth formation and to analyze the effects of physiological disturbances on enamel and dentin formation in deciduous teeth of infants from the Late Epipaleolithic (Natufian) site Shubayqa 1. MATERIALS AND METHODS: Ten deciduous teeth from six infants (ages at death between 21 and 239 days) were analyzed by light and scanning electron microscopy. RESULTS: Marked prism cross-striations and an abnormal wavy course of the prisms were recorded in pre- and postnatal enamel of all analyzed teeth. Single or multiple accentuated incremental lines were observed in prenatal enamel of nine teeth and in postnatal enamel of eight teeth. Accentuated Andresen lines and broader zones exhibiting an enhanced calcospheritic pattern were recorded in the pre- and postnatally formed dentin of nine teeth. DISCUSSION: The structural abnormalities in the pre- and postnatally formed enamel of the infants are considered indicative of chronic stress that negatively affected the activity of secretory ameloblasts. The structural aberrations in pre- and postnatal dentin denote that odontoblasts were also affected by this stress. The presence of single or multiple accentuated incremental lines in pre- and postnatal enamel is interpreted as reflecting (short-term) impacts of higher intensity superimposed on the chronic stress. Our findings suggest compromised maternal health affecting the late fetus and compromised health in newborns. Although limited by the small number of analyzed individuals, the present study contributes to the knowledge of maternal and early infant health conditions in Late Epipaleolithic populations.


Assuntos
Dente Decíduo , Antropologia Física , Esmalte Dentário/diagnóstico por imagem , Esmalte Dentário/crescimento & desenvolvimento , Esmalte Dentário/patologia , Dentina/diagnóstico por imagem , Dentina/crescimento & desenvolvimento , Dentina/patologia , Feminino , História Antiga , Humanos , Lactente , Recém-Nascido , Jordânia , Exposição Materna/história , Gravidez , Estresse Fisiológico , Dente Decíduo/diagnóstico por imagem , Dente Decíduo/crescimento & desenvolvimento , Dente Decíduo/patologia
5.
Am J Phys Anthropol ; 174(1): 144-148, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32914865

RESUMO

The histological identification of interglobular dentine (IGD) in archeological human remains with macroscopic evidence of rickets has opened a promising new avenue for the investigation of metabolic disease in the past. Recent paleopathological studies have shown that histological analysis of archeological human teeth may allow the identification of periods of vitamin D deficiency occurring within very narrow developmental windows, yielding new information on the seasonality or even maternal-fetal transmission of this disease. However, currently available techniques for recording IGD rely on subjective scoring systems or visual estimations, potentially leaving them open to inter and intra-observer error and rendering comparisons of datasets difficult. Here we describe a new imaging protocol that utilizes open access software and may yield more objective and quantitative data on the amount of IGD present within a dentinal region of interest. We demonstrate that grayscale histograms in FIJI®/ImageJ® might be used to provide less subjective estimates of the percentage of a region of interest affected by IGD. Application of this technique may enable more accurate comparison of datasets between researchers.


Assuntos
Dentina/diagnóstico por imagem , Dentina/patologia , Processamento de Imagem Assistida por Computador/métodos , Software , Antropologia Física , Técnicas Histológicas , Humanos , Dente/diagnóstico por imagem , Deficiência de Vitamina D
6.
J Photochem Photobiol B ; 210: 111989, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32818768

RESUMO

New strategies are necessary for the prevention of endodontic infections caused by Enterococcus faecalis, a common resistant pathogen and biofilm producer. Aim of the present study was to compare the effects of Near-Infrared (NIR) Light-Emitting Diode (LED) irradiation and different concentrations of sodium hypochlorite (NaOCl) alone or combined to each other on the E. faecalis biofilm, on artificial and human dentin surfaces. E. faecalis ATCC 29212 preformed biofilms, on polystyrene wells and on dentin discs, were treated with 880 nm NIR irradiation and NaOCl at 4%, 2.5%, 1% and 0.5% alone and combined to each other (NIR irradiation plus NaOCl 1% or 0.5%) at 5 and 10 min. Treated biofilms were compared to the controls for (i) biofilm biomass evaluation, (ii) CFU count for the quantification of cultivable cells and (iii) cells viability. All the detected experimental conditions displayed a significant reduction of biofilm biomass (p < 0.001) and CFUs/mL (p < 0.01) in respect to the controls on both tested surfaces. The effects on the E. faecalis biomass, colony count and cell viability were not time-dependent except for NaOCl 2.5% and 1% in the biofilm biomass reductions on human dentin discs. NIR-LED irradiation alone showed a reduction of E. faecalis aggregates without interfering with cell viability whereas NaOCl alone expressed a killing effect in a concentration dependent way. The combination of NIR-LED irradiation with NaOCl 1% and 0.5% displayed a double effect of cluster disaggregation and cell killing. In particular, NIR-LED irradiation combined with NaOCl 0.5% displayed an anti-biofilm activity major than those expressed by NaOCl 0.5% alone (p = 0.001) with a reduction of biomass 93% vs 71% and 97% vs 25% after 10 min, on polystyrene wells and human dentin discs, respectively. The innovative use of NIR-LED irradiation combined at short times with low concentration of NaOCl (1% and 0.5%) is capable to reach a significant effect on E. faecalis biofilm, especially on human dentin discs.


Assuntos
Biofilmes/efeitos dos fármacos , Enterococcus faecalis/fisiologia , Raios Infravermelhos , Hipoclorito de Sódio/farmacologia , Biofilmes/efeitos da radiação , Dentina/citologia , Dentina/microbiologia , Dentina/patologia , Enterococcus faecalis/efeitos dos fármacos , Humanos , Técnicas In Vitro , Microscopia de Fluorescência , Poliestirenos/química
7.
Folia Med (Plovdiv) ; 62(2): 352-357, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32666763

RESUMO

INTRODUCTION: The full decontamination and disinfection of the root canal system is essential for the success of regenerative endodontic procedures. The current literature does not have information regarding mechanical cleaning of immature teeth with contemporary endodontic instuments. AIM: To compare the thickness and volume of the dentin removed from the roots of immature teeth after endodontic preparation using XP-endo Finisher, GentleFile Brush and a standard H-file scraping technique through micro-computed tomography. METHODS: The study included 51 immature permanent molars. Endodontic access was prepared and without performing preliminary extirpation of the pulp, the teeth were divided into three groups. The first group of teeth were instrumented for two minutes with XP-endo Finisher, the second - two minutes with Gentlefile Brush, in the third group the root canals walls were scraped with a No. 40 H-file. The thickness and the volume of the removed dentin was assessed using micro-CT imaging before and after the use of the instruments. RESULTS: There is no statistically significant difference in the mean values of thickness of dentin removed between the teeth, prepared with XP-endo finisher and Gentlefile Brush. When comparing the mean values of volume of dentin removed between the separate groups, a statistically significant difference was discovered for every compared pair with the highest volume of removed dentin in the group prepared with a hand instrument. CONCLUSION: The endodontic systems tested when used in immature permanent teeth remove significantly less quantity of hard dental structures compared to a hand file for scraping the root canal.


Assuntos
Instrumentos Odontológicos , Dentina/diagnóstico por imagem , Dentição Permanente , Preparo de Canal Radicular/instrumentação , Adolescente , Dentina/patologia , Feminino , Humanos , Técnicas In Vitro , Masculino , Microtomografia por Raio-X
8.
Acta Odontol Latinoam ; 33(1): 27-32, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32621596

RESUMO

The aim of this study was to assess the influence of different pre-treatment approaches on glass ionomer cement (GIC) bond strength (BS) to dentine. Sixty bovine incisors were allocated into six groups according to substrate - sound or caries-affected dentine; and substrate pre-treatment approach - no conditioning (control), polyacrylic acid for 10 s and phosphoric acid for 7 s. Teeth in the caries-affected dentine group were previously submitted to cariogenic pH-cycling challenge. After dentine pre-treatment, according to experimental groups, polyethylene tubes were placed on flat dentine surfaces and filled with GIC. Teeth were stored in distilled water for 24 h at 37 °C and then submitted to microshear test (0.5 mm/min). Failure pattern analysis was performed under stereomicroscope (400x). Data were analysed using two-way ANOVA and Tukey's test (α=5%). Statistically significant differences were found for the pre-treatment approach, regardless of substrate (p<0.001). The polyacrylic acid group and control group had similar BS values, and were both better than the phosphoric acid group. In general, GIC had better bonding performance in sound dentine than in caries-affected dentine. In conclusion, dentine pre-treatment with polyacrylic acid did not improve the performance of GIC restoration on clinically relevant substrates.


Assuntos
Resinas Acrílicas/farmacologia , Colagem Dentária/métodos , Dentina/efeitos dos fármacos , Cimentos de Ionômeros de Vidro/química , Animais , Bovinos , Infiltração Dentária/prevenção & controle , Dentina/diagnóstico por imagem , Dentina/patologia , Teste de Materiais
9.
Ann N Y Acad Sci ; 1475(1): 52-63, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32519363

RESUMO

Cracked teeth are the third most common cause of tooth loss, but there is no reliable imaging tool for the diagnosis of cracks. Here, we demonstrate the feasibility of indocyanine green near-infrared fluorescence (ICG-NIRF) dental imaging for the detection of enamel cracks and enamel-dentin cracks in vitro in the first (ICG-NIRF-I, 700-950 nm) and second (ICG-NIRF-II, 950-1700 nm) imaging windows with transmission excitation light, and compared ICG-NIRF with conventional NIR illumination-II (NIRi-II) and X-ray imaging. Dentin cracks were detected by CT scan, while most enamel cracks, undetectable under X-ray imaging, were clearly visible in NIR images. We found that ICG-NIRF-II detected cracks more effectively than NIRi-II, and that light orientation is an important factor for crack detection: an angled exposure obtained better image contrast of cracks than parallel exposure, as it created a shadow under the crack. Crack depth could be evaluated from the crack shadow in ICG-NIRF and NIRi-II images; from this shadow we could determine crack depth and discriminate enamel-dentin cracks from craze lines. Cracks could be observed clearly from ICG-NIRF images with 1-min ICG tooth immersion, although longer ICG immersion produced images with greater contrast. Overall, our data show that ICG-NIRF dental imaging is a useful tool for diagnosing cracked teeth at an early stage.


Assuntos
Esmalte Dentário/diagnóstico por imagem , Esmalte Dentário/patologia , Verde de Indocianina/química , Espectroscopia de Luz Próxima ao Infravermelho , Dentina/diagnóstico por imagem , Dentina/patologia , Fluorescência , Humanos , Lasers , Raios X
10.
Sci Rep ; 10(1): 9130, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32499552

RESUMO

We aimed to compare subjective (S) vs. objective (O) selective carious tissue removal using hand-excavation versus a self-limiting polymer bur, respectively. A community-based single-blind cluster-randomized controlled superiority trial was performed. This is a 1-year-interim analysis. 115 children (age 7-8 years) with ≥1 vital primary molar with a deep dentin lesion (>1/2 dentin depth) were included (60 S/55 O). The cluster was the child, with eligible molars being treated identically (91 S/86 O). Cavities were prepared and carious tissue on pulpo-proximal walls selectively removed using hand instruments (S), or a self-limiting polymer bur (Polybur P1, Komet). Cavities were restored using glass-hybrid material (Equia Forte, GC). Treatment times and children's satisfaction were recorded. Generalized-linear models (GLM) and multi-level Cox-regression analysis were applied. Initial treatment times were not significantly different between protocols (mean; 95%CI S: 433; 404-462 sec; O: 412; 382-441 sec; p = 0.378/GLM). There was no significant difference in patients' satisfaction (p = 0.164). No pulpal exposures occurred. 113 children were re-examined. Failures occurred in 22/84 O-molars (26.2%) and 26/90 S-molars (28.9%). Pulpal complications occurred in 5(6%) O and 2(2.2%) S molars, respectively. Risk of failure was not significantly associated with the removal protocol, age, sex, dental arch or tooth type (p > 0.05/Cox), but was nearly 5-times higher in multi-surface than single-surface restorations (HR: 4.60; 95% CI: 1.70-12.4). Within the limitations of this interim analysis, there was no significant difference in treatment time, satisfaction and risk of failure between O and S.


Assuntos
Cárie Dentária/cirurgia , Preparo da Cavidade Dentária/métodos , Criança , Preparo da Cavidade Dentária/instrumentação , Dentina/patologia , Feminino , Humanos , Modelos Lineares , Masculino , Dente Molar/patologia , Satisfação do Paciente , Polímeros/química , Modelos de Riscos Proporcionais , Método Simples-Cego
11.
Mater Sci Eng C Mater Biol Appl ; 113: 110956, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32487378

RESUMO

A thermo-responsive injectable bioactive glass (BAG) that has the ability to set at body temperature was prepared using pluronic F127 and hydroxypropyl methylcellulose as the carrier. The injectable composite has the advantage to fill irregular shape implantation sites and quick setting at body temperature. The structural and morphological analysis of injectable BAG before and after setting was done by using Fourier Transform Infrared spectroscopy (FTIR), and Scanning Electron Microscope (SEM). The effect of an ultrasonic scaler for a quick setting of injectable BAG was also investigated. The ultrasonic scaler sets the BAG formulation three-folds faster than at body temperature and homogenized the dispersion. The in vitro bio-adhesion was studied in the bovine tooth in both artificial saliva and deionized water for periodic time intervals, i.e., day 7, 30, 90, and 180, which confirmed the apatite layer formation. The mineral density analysis was used to differentiate the newly formed apatite with tooth apatite. In the MTT assay, the experimental material showed continuous proliferation and cell growth. This indicated that injectable hydrogel promoted cell growth, facilitated proliferation, and had no cytotoxic effect. The SEM and micro-CT results (performed after in vitro bioactivity testing) showed that the injectable BAG had the ability to regenerate dentin, hence this material has the potential to be used for dental and biomedical applications including tooth and bone regeneration in minimally invasive procedures in future.


Assuntos
Cerâmica/química , Implantes Dentários , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cerâmica/farmacologia , Dentina/química , Dentina/patologia , Vidro/química , Camundongos , Nanopartículas/química , Saliva Artificial/química
12.
Mol Genet Genomic Med ; 8(8): e1307, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32495503

RESUMO

BACKGROUND: Matrix metallopeptidase 20 (MMP20) is an evolutionarily conserved protease that is essential for processing enamel matrix proteins during dental enamel formation. MMP20 mutations cause human autosomal recessive pigmented hypomaturation-type amelogenesis imperfecta (AI2A2; OMIM #612529). MMP20 is expressed in both odontoblasts and ameloblasts, but its function during dentinogenesis is unclear. METHODS: We characterized 10 AI kindreds with MMP20 defects, characterized human third molars and/or Mmp20-/- mice by histology, Backscattered Scanning Electron Microscopy (bSEM), µCT, and nanohardness testing. RESULTS: We identified six novel MMP20 disease-causing mutations. Four pathogenic variants were associated with exons encoding the MMP20 hemopexin-like (PEX) domain, suggesting a necessary regulatory function. Mutant human enamel hardness was softest (13% of normal) midway between the dentinoenamel junction (DEJ) and the enamel surface. bSEM and µCT analyses of the third molars revealed reduced mineral density in both enamel and dentin. Dentin close to the DEJ showed an average hardness number 62%-69% of control. Characterization of Mmp20-/- mouse dentin revealed a significant reduction in dentin thickness and mineral density and a transient increase in predentin thickness, indicating disturbances in dentin matrix secretion and mineralization. CONCLUSION: These results expand the spectrum of MMP20 disease-causing mutations and provide the first evidence for MMP20 function during dentin formation.


Assuntos
Amelogênese Imperfeita/genética , Metaloproteinase 20 da Matriz/genética , Mutação , Alelos , Amelogênese Imperfeita/patologia , Animais , Esmalte Dentário/patologia , Dentina/patologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Linhagem
13.
Biosci Rep ; 40(6)2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32495822

RESUMO

Dental pulp stem cells (DPSCs) regenerate injured/diseased pulp tissue and deposit tertiary dentin. DPSCs stress response can be activated by exposing cells to the monomer triethyleneglycol dimethacrylate (TEGDMA) and inducing the DNA-damage inducible transcript 4 (DDIT4) protein expression. The goal of the present study was to determine the impact of TEGDMA on the ability of DPSCs to maintain their self-renewal capabilities, develop and preserve their 3D structures and deposit the mineral. Human primary and immortalized DPSCs were cultured in extracellular matrix/basement membrane (ECM/BM) to support stemness and to create multicellular interacting layers (microtissues). The microtissues were exposed to the toxic concentrations of TEGDMA (0.5 and 1.5 mmol/l). The DPSCs spatial architecture was assessed by confocal microscopy. Mineral deposition was detected by alizarin red staining and visualized by stereoscopy. Cellular self-renewal transcription factor SOX2 was determined by immunocytochemistry. The microtissue thicknesses/vertical growth, surface area of the mineralizing microtissues, the percentage of area covered by the deposited mineral, and the fluorescence intensity of the immunostained cells were quantified ImageJ. DDIT4 expression was determined by a single molecule RNA-FISH technique and the cell phenotype was determined morphologically. DDIT4 expression was correlated with the cytotoxic phenotype. TEGDMA affected the structures of developing and mature microtissues. It inhibited the deposition of the mineral in the matrix while not affecting the SOX2 expression. Our data demonstrate that DPSCs retained their self-renewal capacity although their other functions were impeded. Since the DPSCs pool remained preserved, properties effected by the irritant should be restored by a proper rescue therapy.


Assuntos
Autorrenovação Celular/efeitos dos fármacos , Resinas Compostas/toxicidade , Polpa Dentária/efeitos dos fármacos , Dentina/efeitos dos fármacos , Dentinogênese/efeitos dos fármacos , Polietilenoglicóis/toxicidade , Ácidos Polimetacrílicos/toxicidade , Células-Tronco/efeitos dos fármacos , Adulto , Linhagem Celular , Polpa Dentária/metabolismo , Polpa Dentária/patologia , Dentina/metabolismo , Dentina/patologia , Humanos , Fenótipo , Cultura Primária de Células , Fatores de Transcrição SOXB1/metabolismo , Transdução de Sinais , Células-Tronco/metabolismo , Células-Tronco/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Adulto Jovem
14.
Arch Oral Biol ; 117: 104815, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32585446

RESUMO

AIM: To investigate the chemical and mechanical properties of teeth affected by a 1-bp deletion (c.2688delT) in the DSPP gene. METHODS AND MATERIALS: Maxillary first premolars were extracted from the affected individual at age 9 years due to the orthodontic reason for crowding. A sample was imbedded in epoxy resin and sectioned buccolingually, after micro-computerized tomography (µCT) images were taken. Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometry (EDS) and Vickers microhardness testing were also performed. RESULTS: µCT reconstruction and analysis showed an irregularly obliterated pulp chamber and an extremely small pulpal volume in the DGI-II sample. The mineral density and microhardness scores were smaller in the dentin of the DGI-II sample compared to the wild-type. Mg content was lower in the dentin of the DGI-II sample compared to the wild-type. CONCLUSION: This study shows that dentin affected by a 1-bp deletion in DSPP has a reduced mineral density, diminished microhardness and reduced Mg content.


Assuntos
Dentinogênese Imperfeita , Proteínas da Matriz Extracelular/genética , Fosfoproteínas/genética , Sialoglicoproteínas/genética , Criança , Dentina/patologia , Dentinogênese Imperfeita/diagnóstico por imagem , Dentinogênese Imperfeita/genética , Humanos , Mutação , Linhagem , Deleção de Sequência
15.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(5): 316-322, 2020 May 09.
Artigo em Chinês | MEDLINE | ID: mdl-32392973

RESUMO

Developmental disorders of dental hard tissues are important components of non-carious diseases, which mainly include amelogenesis imperfecta and hereditary dentin disorders with various subtypes. In the absence of effective intervention, these disorders would lead to tooth sensitivity, defects of tooth structure or even loss of tooth, affecting the masticatory function and facial aesthetic configuration. At present, many dental clinicians may not have sufficient understanding of the diseases, and it is urgent to pay attention to the diseases per se and the patients affected. Based on the summary of the current research progresses, this article focuses on the clinical classification, the disease phenotype and the pathogenesis of gene mutations, in order to provide reference and help for the dental clinicians as well as the patients.


Assuntos
Mutação , Doenças Dentárias/genética , Dente/patologia , Amelogênese Imperfeita , Dentina/patologia , Humanos
16.
Int J Nanomedicine ; 15: 2829-2839, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32368057

RESUMO

Objective: To investigate the remineralizing and staining effects of sodium fluoride (NaF) solution with polyethylene glycol-coated silver nanoparticles (PEG-AgNPs) on artificial dentine caries. Materials and Methods: Demineralized human dentine blocks were allocated to three groups. The blocks in group 1 underwent a topical application of a 12% silver diamine fluoride (SDF, 14,150 ppm fluoride) solution. The blocks in group 2 received a topical application of a 2.5% NaF (11,310 ppm fluoride) with PEG-AgNPs (400 ppm silver). The blocks in group 3 received deionized water. All blocks were subjected to pH cycling for 8 days. The surface morphology and cross-sectional features were investigated using scanning electron microscopy (SEM). The color parameters, crystal characteristics, lesion depth, and collagen degradation of the blocks were assessed using digital spectrophotometry, X-ray diffraction (XRD), micro-computed tomography, and spectrophotometry with a hydroxyproline assay, respectively. Results: The SEM showed that dentine collagen was exposed in group 3 but not in groups 1 and 2. The mean lesion depths in groups 1 to 3 were 118±7 µm, 121±14 µm, and 339±20 µm, respectively (groups1,2<3; p<0.001). The data indicated that fluoridated PEG-AgNPs introduced no significant color effect on dentine, but SDF caused distinct discoloration. The XRD indicated that silver chloride was formed in group 1, and fluorapatite was detected in groups 1 and 2. The concentration of hydroxyproline liberated from collagen was significantly less in groups 1 and 2 than in group 3. Conclusion: The use of NaF solution with PEG-AgNPs can remineralize artificial dentine caries and inhibit collagen degradation without causing significant tooth staining.


Assuntos
Cárie Dentária/tratamento farmacológico , Dentina/efeitos dos fármacos , Nanopartículas Metálicas/uso terapêutico , Fluoreto de Sódio/farmacologia , Remineralização Dentária/métodos , Colágeno , Cor , Dentina/metabolismo , Dentina/patologia , Fluoretos/farmacologia , Fluoretos Tópicos/química , Fluoretos Tópicos/farmacologia , Humanos , Hidroxiprolina/metabolismo , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Microscopia Eletrônica de Varredura , Dente Serotino/efeitos dos fármacos , Dente Serotino/patologia , Dente Serotino/ultraestrutura , Polietilenoglicóis/química , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologia , Prata , Compostos de Prata/química , Compostos de Prata/farmacologia , Fluoreto de Sódio/administração & dosagem , Difração de Raios X , Microtomografia por Raio-X
17.
Lasers Med Sci ; 35(7): 1621-1628, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32333336

RESUMO

The aim of this study was to compare the clinical performance of clinical-visual examination using the International Caries Detection and Assessment System (ICDAS) II, digital bitewing radiography, near-infrared light transillumination (NIR-LT), and laser fluorescence (LF) for the detection of non-cavitated proximal enamel and dentin caries. The study included 335 patients, aged 12-18 years, with no cavities in the posterior teeth. Clinical-visual inspections of 335 non-cavitated proximal caries were performed by two examiners. For enamel caries, clinical validation included a combination of clinical-visual and digital bitewing radiography assessments. For dentin caries, the clinical validation was opening the cavity. The accuracy rate, sensitivity, specificity, predictive values, and areas under receiver operating characteristic curves were determined. The agreement between the examiners' measurements was calculated using the kappa coefficient. The sensitivity, specificity, and accuracy of the methods were compared using the McNemar test. The significance level was set at p < 0.05. Digital bitewing radiography had the highest sensitivity (0.96) and accuracy (0.96), and LF had the lowest sensitivity (0.38) and accuracy (0.39). After separation of the lesions into enamel and dentin caries, clinical-visual examination had the highest sensitivity (0.98) and accuracy (0.98) for enamel caries, while digital bitewing radiography had the highest sensitivity (0.97) and accuracy (0.97) for dentin caries. The NIR-LT method had a higher sensitivity for enamel caries (0.86). Each method also differed significantly from the others (p < 0.001). Digital bitewing radiography gave the best prediction of proximal enamel and dentin caries. NIR-LT showed good potential for detection of proximal caries.


Assuntos
Cárie Dentária/diagnóstico por imagem , Cárie Dentária/diagnóstico , Esmalte Dentário/efeitos da radiação , Dentina/efeitos da radiação , Raios Infravermelhos , Lasers , Radiografia Interproximal , Transiluminação , Cárie Dentária/patologia , Esmalte Dentário/diagnóstico por imagem , Dentina/diagnóstico por imagem , Dentina/patologia , Fluorescência , Humanos , Valor Preditivo dos Testes , Curva ROC , Reprodutibilidade dos Testes , Adulto Jovem
18.
Sensors (Basel) ; 20(6)2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32192069

RESUMO

Detecting the extent of occlusal caries is a clinically important but challenging task required for treatment decision making. The aim of this study was to assess the diagnostic power of 3D swept-source optical coherence tomography (OCT) for evaluation of occlusal caries in comparison with X-ray radiography. Extracted human molars not exhibiting American Dental Association (ADA) criteria advanced caries were mounted in a silicone block and digital dental radiographs were captured from the buccal side. Subsequently, occlusal surfaces were scanned with a prototype Yoshida Dental OCT. Thirteen examiners evaluated the presence and extent of caries on radiographs and dynamically sliced 3D OCT video images, using a 4 level scale-0: intact; 1: enamel demineralization without cavitation; 2: enamel caries with cavitation; 3: dentin caries with or without cavitation. Sensitivity, specificity and area under operating characteristic curves (Az) were statistically analyzed (α = 0.05). Reliability analysis showed an excellent agreement among the 13 examiners for both methods. The OCT presented a significantly higher sensitivity and Az value for the detection of caries compared to radiographs (p < 0.05). Radiography showed especially low sensitivity for dentin caries (0-2 versus 3). Dynamic slicing of 3D OCT volumes is a powerful adjunct tool to visual inspection to diagnose the dentin occlusal caries in vitro.


Assuntos
Cárie Dentária/diagnóstico , Diagnóstico Bucal/métodos , Imageamento Tridimensional/métodos , Tomografia de Coerência Óptica/métodos , Cárie Dentária/patologia , Esmalte Dentário/diagnóstico por imagem , Esmalte Dentário/patologia , Dentina/diagnóstico por imagem , Dentina/patologia , Diagnóstico Bucal/instrumentação , Humanos , Imageamento Tridimensional/instrumentação , Curva ROC , Radiografia Dentária/instrumentação , Radiografia Dentária/métodos , Distribuição Aleatória , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia de Coerência Óptica/instrumentação
19.
Vet J ; 255: 105421, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31982081

RESUMO

Fissures on the occlusal surface of equine cheek teeth are commonly encountered during oral examination. Generally, their presence is considered abnormal but their aetiopathogenesis and clinical impact on pulp disease is still undetermined. The aims of this research were to study the extent of occlusal cheek teeth fissures using high-resolution X-ray computed tomography (µCT) imaging and their histological characteristics. Twenty-seven teeth (of 15 horses) were scanned using µCT imaging to analyse fissure extent. Histological examination of a subset of teeth (n=7) was performed. Forty-three type 1 fissures (35 type 1a, eight type 1b) were identified. The mean length of the fissure of type 1a and type 1b on the occlusal surface was 3.47+/-1.60mm and 13.64+/-7.40mm, respectively. Their mean depth was 13.22+/-10.76mm and 7.42+/-6.42mm, respectively. Potential risk factors associated with fissure depth were identified using a multivariable mixed model The location of the fissure and Triadan number were significantly associated with fissure depth. Fissures could be identified on histological sections with the presence of organic material inside the fissure, microorganisms in the continuation of the fissure extending into the dentinal tubules and the presence of reactionary dentine. This study suggests that fissures can provide a pathway for microorganisms to enter the dentinal tubules, potentially resulting in local pulpal inflammation. It appears that in healthy teeth, vital odontoblasts react by producing reactionary (tertiary) dentin, which lacks patent tubules and thus provides a proper seal.


Assuntos
Fissuras Dentárias/veterinária , Doenças dos Cavalos/patologia , Dente Molar/patologia , Animais , Fissuras Dentárias/diagnóstico por imagem , Fissuras Dentárias/epidemiologia , Fissuras Dentárias/microbiologia , Dentina/patologia , Doenças dos Cavalos/epidemiologia , Cavalos , Tomografia Computadorizada por Raios X/veterinária
20.
J Endod ; 46(2): 252-257, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31831180

RESUMO

INTRODUCTION: This study evaluated 4 different light-emitting diode (LED) transilluminators and the impact of operator experience in the detection of dentinal defects through an ex vivo TRUEJAW surgical model (Dental Engineering Laboratories, Santa Barbara, CA). METHODS: Forty-four extracted and endodontically treated mandibular premolar teeth were evaluated. Teeth were mounted in the models followed by surgical flaps and osteotomies to expose the apical third of the roots. After apical resection, the root-end surfaces were randomly inspected for the presence or absence of dentinal defects using a dental operating microscope (DOM) at ×19.4 magnification by experienced and novice LED evaluators. The assessment was made with the DOM light and 4 masked LED transilluminators of different diameters and luminous flux. The teeth were examined outside the models to establish the ground truth. The sensitivity, specificity, and kappa and McNemar test values of each light source by examiner were calculated. RESULTS: The use of LED transilluminators improved the diagnostic sensitivity of dentinal defects when compared with the DOM light alone for both examiners. For the LED-experienced evaluator, the medium-low transilluminator had statistically significant higher sensitivity than the DOM light and the small-low and small-high transilluminators (P < .05). For the novice LED evaluator, the medium-high transilluminator had the highest sensitivity. There was a statistically significant difference between the sensitivities of the medium-low transilluminator between the examiners (P < .05). CONCLUSIONS: Within the limitations of this ex vivo surgical study, dentinal defects were more often detected with the LED transilluminators with a larger diameter and increased lumens. The operator's LED transilluminator experience was found to have a positive effect on the detection of dentinal defects using transillumination.


Assuntos
Dentina , Microcirurgia , Transiluminação , Dente Pré-Molar , Equipamentos Odontológicos , Dentina/patologia , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...