RESUMO
Oral health problems may occur as a result of the ingestion of acid drinks. The objective of this in vitro study was to quantify and screen the concentration of potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), manganese (Mn), zinc (Zn), iron (Fe), copper (Cu), barium (Ba), lead (Pb), arsenic (As), cadmium (Cd), aluminum (Al), cobalt (Co), chromium (Cr), molybdenum (Mo), sodium (Na), nickel (Ni), selenium (Se), and vanadium (V) released from bovine incisors during an erosive challenge at different times of exposure when immersed in Coca-Cola™, orange juice, and grape juice. A total of 240 samples of bovine incisor teeth were used for the erosive challenge and allocated in groups. Digestion of drinks was performed using microwave-assisted digestion. The content in acidic drinks was monitored before and after the erosive challenge at exposure times of 1, 5, and 60 min using inductively coupled plasma optical emission spectrometry (ICP OES). The drinks' pH varied slightly during the erosive challenge but remained below the critical value of pH 5 to cause tooth demineralization. The concentrations of elements released from the bovine incisors during the in vitro erosive challenge depend on exposure times when immersed in acidic beverages. For some elements such as Ca, Mn, Zn, Fe, Cu, Ba, Pb, As, and Cd, quantified in acidic drinks, grape juice had greater erosive potential than Coca-Cola™ and orange juice. Quantification and monitoring of chemical elements in bovine teeth can be performed considering a longer erosive time and other types of acidic drinks. Further analysis using human teeth is still not available and must be conducted. The demineralization of teeth not only occurs in acidic beverages; physical and chemical factors play other roles and should be investigated.
Assuntos
Bebidas Gaseificadas/efeitos adversos , Sucos de Frutas e Vegetais/efeitos adversos , Minerais/análise , Desmineralização do Dente/metabolismo , Animais , Bovinos , Modelos Animais de Doenças , Concentração de Íons de Hidrogênio , Incisivo/química , Incisivo/efeitos dos fármacos , Micro-Ondas , Espectrofotometria Atômica , Desmineralização do Dente/induzido quimicamenteRESUMO
The reduced hardware design of narrow implants increases the risk of fracture not only of the implant itself but also of the prosthetic constituents. Hence, the current study is aimed at estimating the probability of survival of anterior crowns supported by different narrow implant systems. Three different narrow implant systems of internal conical connections were evaluated (Ø3.5 × 10 mm): (i) Active (Nobel Biocare), (ii) Epikut (S.I.N. Implant System), and (iii) BLX (Straumann). Abutments were torqued to the implants, and standardized maxillary incisor crowns were cemented. The assemblies were subjected to step-stress accelerated life testing (SSALT) in water through load application of 30 degrees off-axis lingually at the incisal edge of the crowns using a flat tungsten carbide indenter until fracture or suspension. The use level probability Weibull curves and reliability for completion of a mission of 100,000 cycles at 80 N and 120 N were calculated and plotted. Weibull modulus and characteristic strength were also calculated and plotted. Fractured samples were analyzed in a stereomicroscope. The beta (ß) values were 1.6 (0.9-3.1) and 1.4 (0.9-2.2) for BLX and Active implants, respectively, and 0.5 (0.3-0.8) for the Epikut implant, indicating that failures were mainly associated with fatigue damage accumulation in the formers, but more likely associated with material strength in the latter. All narrow implant systems showed high probability of survival (≥95%, CI: 85-100%) at 80 and 120 N, without significant difference between them. Weibull modulus ranged from 6 to 14. The characteristic strength of Active, Epikut, and BLX was 271 (260-282) N, 216 (205-228) N, and 275 (264-285) N, respectively. The failure mode predominantly involved abutment and/or abutment screw fracture, whereas no narrow implant was fractured. Therefore, all narrow implant systems exhibited a high probability of survival for anterior physiologic masticatory forces, and failures were restricted to abutment and abutment screw.
Assuntos
Projeto do Implante Dentário-Pivô/métodos , Coroas , Dente Suporte , Falha de Restauração Dentária , Análise do Estresse Dentário/métodos , Humanos , Incisivo/química , Teste de Materiais/métodos , Maxila/química , Microscopia Eletrônica de Varredura/métodos , Probabilidade , Próteses e Implantes , Reprodutibilidade dos Testes , Estresse Mecânico , Propriedades de Superfície , Torque , Água/químicaRESUMO
Conducting research in the field of forensic sciences with methodologies that simulate situations found in the day-to-day practice of a given field of expertise is relevant insofar as this approach can produce results that are as close as possible to reality. In this context, the present study provided situations based on burial in a mangrove environment to estimate the changes in the mechanical properties (Knoop microhardness, roughness and color) of dental restorations utilizing silver amalgam, composite resin and glass ionomer cement over the time of burial. The silver amalgam showed a significant increase in surface roughness and a reduction in Knoop microhardness. Composite resin showed a statistically significant increase in color variation, and the glass ionomer cement showed significant increases in color variation and Knoop microhardness. These results allowed us to conclude that teeth restored with silver amalgam, composite resin and glass ionomer cement submitted to burial in mangrove environments produce different changes in surface roughness, Knoop microhardness and color properties depending on the time of burial to which the victims were submitted. These proprieties could help the forensic sciences to estimate time intervals for burial in mangrove environments.
Assuntos
Resinas Compostas/análise , Amálgama Dentário/análise , Restauração Dentária Permanente/métodos , Cimentos de Ionômeros de Vidro/análise , Incisivo/química , Propriedades de Superfície , Animais , Brasil , Sepultamento , Bovinos , Cor , Odontologia Legal , Mudanças Depois da Morte , Áreas AlagadasRESUMO
OBJECTIVE: This study investigated the anti-demineralizing and antibacterial effects of a propolis ethanolic extract (EEP) against Streptococcus mutans dental biofilm. DESIGN: Blocks of sound bovine enamel (n=24) were fixed on polystyrene plates. S. mutans inoculum (ATCC 25175) and culture media were added (48 h-37 °C) to form biofilm. Blocks with biofilm received daily treatment (30 µL/1 min), for 5 days, as following: G1 (EEP 33.3%); G2 (chlorhexidine digluconate 0.12%); G3 (ethanol 80%); and G4 (Milli-Q water). G5 and G6 were blocks without biofilm that received only EEP and Milli-Q water, respectively. Final surface hardness was evaluated and the percentage of hardness loss (%HL) was calculated. The EEP extract pH and total solids were determined. S. mutans count was expressed by log10 scale of Colony-Forming Units (CFU/mL). One way ANOVA was used to compare results which differed at a 95% significance level. RESULTS: G2 presented the lowest average %HL value (68.44% ± 12.98) (p=0.010), while G4 presented the highest (90.49% ± 5.38%HL) (p=0.007). G1 showed %HL (84.41% ± 2.77) similar to G3 (87.80% ± 6.89) (p=0.477). Groups G5 and G6 presented %HL=16.11% ± 7.92 and 20.55% ± 10.65; respectively (p=0.952). G1 and G4 differed as regards to S. mutans count: 7.26 ± 0.08 and 8.29 ± 0.17 CFU/mL, respectively (p=0.001). The lowest bacterial count was observed in chlorhexidine group (G2=6.79 ± 0.10 CFU/mL) (p=0.043). There was no difference between S. mutans count of G3 and G4 (p=0.435). The EEP showed pH 4.8 and total soluble solids content=25.9 Brix. CONCLUSION: The EEP seems to be a potent antibacterial substance against S. mutans dental biofilm, but presented no inhibitory action on the de-remineralization of caries process.
Assuntos
Biofilmes/efeitos dos fármacos , Esmalte Dentário/efeitos dos fármacos , Própole/farmacologia , Streptococcus mutans/efeitos dos fármacos , Desmineralização do Dente/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Carga Bacteriana/efeitos dos fármacos , Abelhas , Biofilmes/crescimento & desenvolvimento , Bovinos , Células Cultivadas , Clorexidina/farmacologia , Ácidos Cumáricos/química , Cárie Dentária/prevenção & controle , Esmalte Dentário/química , Dureza/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Incisivo/química , Incisivo/efeitos dos fármacos , Incisivo/microbiologia , Própole/química , Streptococcus mutans/fisiologia , Propriedades de Superfície , Desmineralização do Dente/prevenção & controleRESUMO
AIM: The purpose of this study was to characterise the enamel surface of sound deciduous teeth in terms of morphology, chemical composition, structure and crystalline phases. MATERIALS AND METHODS: The enamel of 30 human deciduous teeth was examined by: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). Chemical differences between incisors and canines were statistically evaluated using the Mann-Whitney U test (p ≤ 0.05). RESULTS: Three enamel patterns were observed by SEM: 'mostly smooth with some groves', 'abundant microporosities' and 'exposed prisms'. The average Ca/P molar ratios were 1.37 and 1.03 by EDS and XPS, respectively. The crystallite size determined by XRD was 210.82 ± 16.78 Å. The mean ratio between Ca bonded to phosphate and Ca bonded to hydroxyl was approximately 10:1. CONCLUSION: The enamel of sound deciduous teeth showed two main patterns: 'mostly smooth with some groves' and 'abundant microporosities'. 'Exposed prisms' was a secondary pattern. There were slight variations among the Ca/P molar ratios found by EDS and XPS, suggesting differences in the mineral content from the enamel surface to the interior. The crystalline phases found in enamel were hydroxyapatite and carbonate apatite, with major type B than type A carbonate incorporation.
Assuntos
Esmalte Dentário/ultraestrutura , Dente Decíduo/ultraestrutura , Apatitas/análise , Cálcio/análise , Cristalografia , Dente Canino/química , Dente Canino/ultraestrutura , Esmalte Dentário/química , Durapatita/análise , Humanos , Hidróxidos/análise , Incisivo/química , Incisivo/ultraestrutura , Microscopia Eletrônica de Varredura , Fosfatos/análise , Fósforo/análise , Espectroscopia Fotoeletrônica , Porosidade , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Dente Decíduo/química , Difração de Raios XRESUMO
The purpose of this study was to evaluate the shear bond strength, the adhesive remnant index scores, and etch surface of teeth prepared for orthodontic bracket bonding with self-etching primer and Er:YAG laser conditioning. One hundred and twenty bovine incisors were randomly divided into four groups. In Group I (Control), the teeth were conditioned with 35% phosphoric acid for 15 seconds. In Group II the teeth were conditioned with Transbond Plus SEP (5 sec); III and IV were irradiated with the Er:YAG 150 mJ (11.0 J/cm²), 150 mJ (19.1 J/cm²), respectively, at 7-12 Hz with water spray. After surface preparation, upper central incisor stainless steel brackets were bonded with Transbond Plus Color Change Adhesive. The teeth were stored in water at 37°C for 24 hours and shear bond strengths were measured, and adhesive remnant index (ARI) was determined. The conditioned surface was observed under a scanning electron microscope. One-way ANOVA and chi-square test were used. Group I showed the significantly highest values of bond strength with a mean value of 8.2 megapascals (MPa). The lesser amount of adhesive remnant was found in Group III. The results of this study suggest that Er:YAG laser irradiation could not be an option for enamel conditioning.
Assuntos
Condicionamento Ácido do Dente/métodos , Cimentos Dentários/química , Esmalte Dentário/química , Incisivo/química , Incisivo/efeitos da radiação , Lasers de Estado Sólido , Braquetes Ortodônticos , Adesividade/efeitos da radiação , Animais , Bovinos , Esmalte Dentário/efeitos da radiação , Análise do Estresse Dentário , Terapia a Laser/métodos , Resistência ao Cisalhamento/efeitos da radiação , Estresse Mecânico , Propriedades de Superfície/efeitos da radiação , Resistência à Tração/efeitos da radiação , Resultado do TratamentoRESUMO
This study assessed the anti-biofouling performance of an experimental adhesive system containing a naturally occurring essential vegetable oil and examined the following physical and mechanical properties: water sorption (WS) and solubility (SL), microtensile bond strength to dentin (µTBS), and degree of conversion. The following six groups were tested: a self-etching experimental adhesive containing refined essential oil from the seeds of the Butia capitata tree (EAO); an oil-free version of the experimental adhesive (EANO); one group without adhesive as the control (C); and the three following commercial self-etching adhesives: Clearfil Protect Bond (CPB), Clearfil SE Bond, and Adper SE Plus. The antibacterial effect was estimated by microbiological culture on selective/non-selective media, and the results expressed as colony-forming units per unit weight of dry biofilm (CFU mg(-1)). The data were submitted to ANOVA and Tukey's post hoc test (α = 0.05). After 24 h, pH changes were similar in the storage medium of all tested adhesive systems. EAO showed similar levels of antimicrobial activity in a model biofilm microcosm as the commercial self-etching adhesive CPB. Both were effective against total microorganisms, aciduric bacteria, lactobacilli, and Streptococcus mutans. WS and SL were not affected by the presence of the essential oil; the values of EAO were similar to or less than those of commercial equivalents. The incorporation of an essential oil into an experimental adhesive did not influence its monomer conversion result. Immediate µTBS values of EAO and EANO were similar and were greater than those of commercial equivalents. After storage for 6 months, the µTBS of the EAO decreased significantly and became similar to the values of commercial equivalents, while the strength of the EANO was not affected.
Assuntos
Biofilmes/efeitos dos fármacos , Incrustação Biológica/prevenção & controle , Cimentos Dentários/química , Óleos Voláteis/química , Resistência à Tração , Análise de Variância , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Arecaceae/química , Bovinos , Contagem de Colônia Microbiana , Cimentos Dentários/farmacologia , Dentina/química , Incisivo/química , Lactobacillus/efeitos dos fármacos , Óleos Voláteis/farmacologia , Sementes/química , Solubilidade , Streptococcus mutans/efeitos dos fármacosRESUMO
This study evaluated the effect of the systemic use of sodium alendronate in rats in vivo. Forty-five Wistar rats aged 36 to 42 days and weighing 200 to 230 g were randomly assigned to a control group (n = 20), which received distilled water, and an experimental group (n = 25), which received 2 weekly doses of 1 mg/kg of chemically pure sodium alendronate. The animals were killed after 60 days of treatment. The tibias were removed for analysis of bone mineral density by dual-energy X-ray absorptiometry (DXA). Then, the maxillary incisors were extracted for analysis of the mineralized dental tissues using fluorescence spectroscopy (FS), scanning electron microscopy (SEM), bright field microscopy (BFM), and cross-sectional microhardness (CSMH) testing. DXA and CSMH data were subjected to statistical analysis by Kruskal-Wallis test (5% significance level). The experimental group presented higher bone mineral density than the control group by DXA. FS analysis revealed presence of alendronate in the mineralized dental tissues of the specimens of the experimental group. Significant morphological differences were not found by SEM and BFM. Enamel and dentin (100 and 300 µm from the dentinoenamel junction) CSMH data did not show significant difference between the control and experimental groups. Based on the obtained results, we conclude that while alendronate increased the bone mineral density and was incorporated into the mineralized dental tissues it did not cause significant alterations in the morphology and microhardness of rat incisor enamel and dentin.
Assuntos
Alendronato/administração & dosagem , Conservadores da Densidade Óssea/administração & dosagem , Incisivo/química , Absorciometria de Fóton , Animais , Densidade Óssea , Testes de Dureza , Microscopia , Ratos , Ratos Wistar , Espectrometria de Fluorescência , Tíbia/químicaRESUMO
PURPOSE: The aim of this study was to evaluate the nanoleakage patterns between dental enamel and reinforced leucite ceramic, bonded with resin luting systems and a flowable composite resin. MATERIALS AND METHODS: Twelve crowns of bovine incisors were randomly divided into four groups (n = 3) according to the luting procedure: Excite/Variolink II, Clearfil SE Bond/Panavia F, Scotchbond Multi-PURPOSE Plus/RelyX ARC, and Single Bond 2/Filtek Z350 Flow. To evaluate the nanoleakage patterns, IPS Empress Esthetic disks (5 mm Ø and 1.2-mm thick) were bonded to enamel, and, after 24 h, the specimens were immersed in a 50% (w/v) solution of silver nitrate (24 h), fixed, dehydrated, and processed scanning electron microscopy (SEM). RESULTS: None nanoleakage on interface of the groups that Single Bond 2 followed by the flowable composite were used. The highest percentage of nanoleakage was shown by the Excite/Variolink II protocol. Also, in all conditions tested, none silver nitrate uptake was observed between the leucite-reinforced ceramic and the resin luting cement. CONCLUSIONS: The use of a two-step etch-and-rinse adhesive with flowable composite was able to promote an adequate seal of the bond interface at the enamel. Moreover, the conventional dual-cured resin cements associated with simplified and dual-cured adhesives tested are also indicated to bond thin ceramics to enamel, since all presented low silver nitrate uptake.
Assuntos
Silicatos de Alumínio/análise , Cerâmica/análise , Colagem Dentária/métodos , Esmalte Dentário/química , Incisivo/química , Cimentos de Resina/análise , Animais , BovinosRESUMO
PURPOSE: This work aims to study the erosion on restorative materials and on surrounding dentin. Fifty root dentin samples were obtained from bovine incisors. METHODS: Twenty samples were not restored and thirty received cavity preparations. Samples were assigned to five groups: G1, G2: sound dentin (D); G3: composite resin (CR); G4: resin-modified glass-ionomer cement (RMGIC); G5: glass-ionomer cement (GIC). The samples of groups 2-5 were submitted to six cycles (demineralization-remineralization). Samples were analyzed by micro energy-dispersive X-ray fluorescence spectrometry (µ-EDXRF) and by scanning electron microscopy (SEM). RESULTS: Mineral loss was greater in G2 samples than in RMGI > CR > GIC > D (control). SEM images showed pronounced dentin demineralization in groups 2 and 4. The acid erosion has a significant effect on mineral loss (Ca and P) of root dentin without restoration. CONCLUSIONS: Composite resin had the best chemical resistance to erosion among all the materials. Fluoride contained in GIC seemed to cause some protection, however, with material degradation. Chemical interaction of tooth-colored dental materials with root dentin could be assessed by µ-EDXRF.
Assuntos
Materiais Dentários/química , Dentina/química , Incisivo/anatomia & histologia , Incisivo/química , Erosão Dentária , Animais , Bovinos , Microscopia Eletrônica de Varredura , Minerais/análise , Espectrometria por Raios XRESUMO
AIM: Our aim was to test the hypothesis that co-exposure to lead and fluoride alter the severity of enamel fluorosis. MATERIALS AND METHODS: Wistar rats were allocated in four groups: control, and 3 groups that received water containing 100 ppm of fluoride (F), 30 ppm of lead (Pb), or 100 ppm of F and 30 ppm of Pb (F+Pb) from the beginning of gestation. Enamel analysis and F and Pb determinations in enamel, dentine, and bone were performed in 81-day-old animals. Fluorosis was quantified using a new fluorosis index based on the identification of incisor enamel defects (white bands and white islets, representing hypomineralization, and cavities) weighted according to their severity and quantity. Hypomineralization was validated histopathologically by polarizing microscopy and microradiography. Scores were given by two blinded calibrated examiners (intra and interexaminer kappa values were 0.8 and 0.86, respectively). RESULTS: The control and the Pb groups presented normal enamel. The F+Pb group presented more severe enamel defects compared with the F group (P<0.0001). CONCLUSIONS: This study shows that lead exacerbates dental fluorosis in rodents, suggesting that co-exposure to lead may affect the degree of fluorosis.
Assuntos
Cariostáticos/efeitos adversos , Exposição Ambiental , Fluoretos/efeitos adversos , Fluorose Dentária/etiologia , Chumbo/efeitos adversos , Animais , Cariostáticos/análise , Cárie Dentária/induzido quimicamente , Cárie Dentária/patologia , Esmalte Dentário/química , Dentina/química , Sinergismo Farmacológico , Feminino , Fêmur/química , Fluoretos/análise , Fluorose Dentária/classificação , Fluorose Dentária/patologia , Incisivo/química , Chumbo/análise , Chumbo/sangue , Masculino , Microrradiografia , Microscopia de Polarização , Fósforo/análise , Distribuição Aleatória , Ratos , Ratos Wistar , Calcificação de Dente/efeitos dos fármacos , Desmineralização do Dente/induzido quimicamente , Desmineralização do Dente/classificação , Desmineralização do Dente/patologia , Abastecimento de Água/análiseRESUMO
OBJETIVO: Investigar os fatores de risco ou de proteção para a fluorose dentária na dentição permanente de crianças de 6 a 8 anos em um bairro no Município de Fortaleza, Brasil. MÉTODOS: Este estudo de caso-controle incluiu 67 crianças com fluorose nos incisivos superiores e inferiores permanentes erupcionados, conforme o índice de Dean, e 57 controles. A presença de fluorose foi determinada como variável dependente. Os dados acerca das variáveis independentes foram obtidos através de entrevistas com os pais das crianças. O teste exato de Fisher foi utilizado para verificar a existência de associação entre fluorose e as variáveis independentes. Foi calculada a razão de chances (odds ratio, OR) para verificar a associação e a probabilidade de fluorose no grupo-caso, ambos com significância de 95 por cento. RESULTADOS: Houve associação significativa da fluorose com tipo de moradia (própria, alugada ou ocupada), mas não com fonte de água para consumo ou uso de dentifrícios fluoretados e suplementos de flúor. Na análise univariada, o risco de fluorose foi maior em crianças que iniciaram o consumo de leite em pó reconstituído com água antes dos 2 anos de idade (OR = 4,53; IC95 por cento: 1,07 a 26,74) e nas que não mamaram (OR = 6,66; IC95 por cento: 1,61 a 38,62). Na análise multivariada, somente a amamentação apresentou associação com a fluorose (4,54; IC95 por cento: 1,21 a 16,66). CONCLUSÕES: A amamentação se configurou como fator de proteção contra a fluorose. É preciso estabelecer critérios de classificação mais específicos para permitir a investigação de relações entre fluorose e classe socioeconômica.
OBJECTIVE: To investigate protection or risk factors for dental fluorosis in permanent teeth of 6 to 8 year-old children in a neighborhood of Fortaleza, Brazil. METHODS: This case-control study included 57 controls and 67 children with fluorosis affecting superior and inferior incisors teeth as determined by the Dean classification criteria. Presence of fluorosis was considered as the dependent variable. Data concerning independent variables were obtained through interviews with the parents. Fisher's exact test was used to determine associations between fluorosis and the independent variables. Odds ratios (OR) were calculated to investigate associations and likelihood of fluorosis in the case group, with 95 percent significance level. RESULTS: Fluorosis was significantly associated with type of housing (owned, rented or squatted), but not with the source of drinking water or use of fluoridated toothpaste and fluoride supplements. Univariate analysis showed that the risk of fluorosis was higher in children who began drinking powdered milk mixed with water before 2 years of age (OR = 4.53; IC95 percent: 1.07-26.74) and in those who did not breastfeed (OR = 6.66; IC95 percent: 1.61-38.62). In the multivariate analysis, only breastfeeding was associated with fluorosis (4.54; IC95 percent: 1.21-16.66). CONCLUSIONS: Breastfeeding was a protection factor against fluorosis. More specific categorization criteria must be established to investigate relationships between fluorosis and socioeconomic class.
Assuntos
Humanos , Masculino , Feminino , Criança , Fluorose Dentária/epidemiologia , Brasil/epidemiologia , Aleitamento Materno , Cariostáticos/administração & dosagem , Cariostáticos/efeitos adversos , Estudos de Casos e Controles , Suplementos Nutricionais/efeitos adversos , Fluoretação , Fluoretos/análise , Fluorose Dentária/etiologia , Fluorose Dentária/prevenção & controle , Habitação , Incisivo/química , Fatores de Risco , Fatores Socioeconômicos , Cremes Dentais/efeitos adversos , Abastecimento de Água/análiseRESUMO
Considering that blood fluoride concentration varies according to fluoride exposure and that dental fluorosis is related to the amount of enamel formed under a given fluoride dose, the present study investigated whether the fluorosis produced by an oscillating chronic fluoride dose would be similar to that caused by exposure to a constant dose, representing the mean of the oscillation during a given time. Rats received during 78 days water with fluoride concentrations of 0, 12.5, 25 or 37.5 microg F/mL, or oscillating concentrations of 12.5 and 37.5 microg F/mL every 72 h (mean exposure=25 microg F/mL). The concentrations of fluoride in the plasma, femur and incisors of the rats were determined at the end of the experimental period. Also, the enamel dental fluorosis index was determined in the incisors using a quantitative method developed by our research group named Dental Fluorosis by Image Analysis (DFIA). Fluoride concentrations in plasma, femur and teeth, and DFIA increased linearly for constant fluoride concentrations in water (p<0.0001, r values=0.87-0.98). The results of the oscillating group and the groups receiving 25 microg F/mL did not differ significantly (p>0.05). The findings of this study suggest that in animals chronically exposed to symmetrically oscillating fluoride doses, the resulting dental fluorosis reflects the metabolic effect of the mean of the oscillating doses.
Assuntos
Cariostáticos/farmacocinética , Fluoretos/farmacocinética , Fluorose Dentária/classificação , Processo Alveolar/química , Animais , Cariostáticos/administração & dosagem , Cariostáticos/análise , Esmalte Dentário/química , Relação Dose-Resposta a Droga , Feminino , Fêmur/química , Fluoretos/administração & dosagem , Fluoretos/sangue , Processamento de Imagem Assistida por Computador/métodos , Incisivo/química , Mandíbula/química , Fotografia Dentária/métodos , Distribuição Aleatória , Ratos , Ratos Wistar , Método Simples-Cego , Ápice Dentário/química , Abastecimento de Água/análiseRESUMO
Considering that blood fluoride concentration varies according to fluoride exposure and that dental fluorosis is related to the amount of enamel formed under a given fluoride dose, the present study investigated whether the fluorosis produced by an oscillating chronic fluoride dose would be similar to that caused by exposure to a constant dose, representing the mean of the oscillation during a given time. Rats received during 78 days water with fluoride concentrations of 0, 12.5, 25 or 37.5 µg F/mL, or oscillating concentrations of 12.5 and 37.5 µg F/mL every 72 h (mean exposure=25 µg F/mL). The concentrations of fluoride in the plasma, femur and incisors of the rats were determined at the end of the experimental period. Also, the enamel dental fluorosis index was determined in the incisors using a quantitative method developed by our research group named Dental Fluorosis by Image Analysis (DFIA). Fluoride concentrations in plasma, femur and teeth, and DFIA increased linearly for constant fluoride concentrations in water (p<0.0001, r values=0.87-0.98). The results of the oscillating group and the groups receiving 25 µg F/mL did not differ significantly (p>0.05). The findings of this study suggest that in animals chronically exposed to symmetrically oscillating fluoride doses, the resulting dental fluorosis reflects the metabolic effect of the mean of the oscillating doses.
Considerando que a concentração de fluoreto no sangue varia de acordo com a exposição ao fluoreto, e que a fluorose dental está relacionada com a quantidade de esmalte formado sob determinada dose de fluoreto, este estudo avaliou se a fluorose resultante da exposição a doses oscilantes de fluoreto seria semelhante àquela causada pela exposição a uma dose constante, representativa da média das oscilações durante um determinado tempo. Durante 78 dias, ratos receberam água com concentrações constantes de fluoreto de 0; 12,5; 25 ou 37,5 µg F/mL, ou concentrações oscilantes de 12,5 e 37,5 µg F/mL alternados a cada 72 h (média de exposição = 25 µg F/mL). Concentrações de fluoreto no plasma, fêmur e dentes incisivos dos ratos foram determinadas após o período experimental. O índice de fluorose, observado nos incisivos dos ratos, foi quantificado usando um método de análise de imagem desenvolvido para essa pesquisa, denominado de índice de fluorose por análise de imagem (DFIA, em Inglês). A concentração de fluoreto no plasma, fêmur e incisivo dos ratos, assim como o DFIA, aumentaram de forma linear para as concentrações constantes de fluoreto na água (p<0,0001, r=0,87-0,98). Não houve diferença significativa entre o grupo que recebeu doses oscilantes e o grupo que recebeu 25 µg F/mL (p>0,05). Os resultados sugerem a fluorose dental decorrente de exposição crônica de animais a doses de fluoreto oscilantes e simétricas reflete o efeito metabólico da média da oscilação.
Assuntos
Animais , Feminino , Ratos , Cariostáticos/farmacocinética , Fluoretos/farmacocinética , Fluorose Dentária/classificação , Processo Alveolar/química , Cariostáticos/administração & dosagem , Cariostáticos/análise , Relação Dose-Resposta a Droga , Esmalte Dentário/química , Fêmur/química , Fluoretos/administração & dosagem , Fluoretos/sangue , Processamento de Imagem Assistida por Computador/métodos , Incisivo/química , Mandíbula/química , Fotografia Dentária/métodos , Distribuição Aleatória , Ratos Wistar , Método Simples-Cego , Ápice Dentário/química , Abastecimento de Água/análiseRESUMO
OBJECTIVE: To investigate protection or risk factors for dental fluorosis in permanent teeth of 6 to 8 year-old children in a neighborhood of Fortaleza, Brazil. METHODS: This case-control study included 57 controls and 67 children with fluorosis affecting superior and inferior incisors teeth as determined by the Dean classification criteria. Presence of fluorosis was considered as the dependent variable. Data concerning independent variables were obtained through interviews with the parents. Fisher's exact test was used to determine associations between fluorosis and the independent variables. Odds ratios (OR) were calculated to investigate associations and likelihood of fluorosis in the case group, with 95% significance level. RESULTS: Fluorosis was significantly associated with type of housing (owned, rented or squatted), but not with the source of drinking water or use of fluoridated toothpaste and fluoride supplements. Univariate analysis showed that the risk of fluorosis was higher in children who began drinking powdered milk mixed with water before 2 years of age (OR = 4.53; IC95%: 1.07-26.74) and in those who did not breastfeed (OR = 6.66; IC95%: 1.61-38.62). In the multivariate analysis, only breastfeeding was associated with fluorosis (4.54; IC95%: 1.21-16.66). CONCLUSIONS: Breastfeeding was a protection factor against fluorosis. More specific categorization criteria must be established to investigate relationships between fluorosis and socioeconomic class.
Assuntos
Fluorose Dentária/epidemiologia , Brasil/epidemiologia , Aleitamento Materno , Cariostáticos/administração & dosagem , Cariostáticos/efeitos adversos , Estudos de Casos e Controles , Criança , Suplementos Nutricionais/efeitos adversos , Feminino , Fluoretação , Fluoretos/análise , Fluorose Dentária/etiologia , Fluorose Dentária/prevenção & controle , Habitação , Humanos , Incisivo/química , Masculino , Fatores de Risco , Fatores Socioeconômicos , Cremes Dentais/efeitos adversos , Abastecimento de Água/análiseRESUMO
The effects of laser etching, decontamination, and storage treatments on dentin components were studied using Fourier transform (FT)-Raman spectroscopy. Thirty bovine incisors were prepared to expose the dentin surface and then divided in two main groups based upon the decontamination process and storage procedure: autoclaved (group A, n=15) or stored in thymol aqueous solution (group B, n=15). The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control subgroup) or irradiated with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ, and total energy of 12 J). Samples were analyzed by FT-Raman spectroscopy; we collected three spectra for each area (before and after treatment). The integrated areas of five Raman peaks were calculated to yield average spectra. The areas of the peaks associated with phosphate content (P<0.001), type I collagen, and organic C-H bonds (P<0.05) were reduced significantly in group A (control). Analyses of samples irradiated with reduced laser energies did not show significant changes in the dentin components. These results suggest that thymol storage treatment is advised for in vitro study; furthermore, 12 J of Er:YAG laser energy does not affect dentin components.
Assuntos
Dentina/química , Dentina/efeitos da radiação , Lasers de Estado Sólido , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , Animais , Bovinos , Relação Dose-Resposta à Radiação , Técnicas In Vitro , Incisivo/química , Incisivo/efeitos da radiação , Doses de RadiaçãoRESUMO
The effects of laser etching, decontamination, and storage treatments on dentin components were studied by energy-dispersive X-ray fluorescence spectrometry (EDXRF). Thirty bovine incisors were prepared to expose the dentin surface and then divided into two main groups based upon the decontamination process and storage procedure: autoclaved (group A, n=15) or stored in aqueous thymol solution (group B, n=15). The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control subgroup) or irradiated with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ). Samples were analyzed by micro-EDXRF, yielding three spectra for each area (before and after treatment). Surface mappings covering an area of 80x60 points with steps of 20 mum were also performed on selected specimens. The amount of Ca and P in group A specimens decreased significantly (P<0.05) after the acid etching and the CaP ratio increased (P<0.001). Er:YAG laser-etching using lower laser energies did not produce significant changes in dentin components. The mapping data support the hypothesis that acid etching on dentin produced a more chemically homogeneous surface and thus a more favorable surface for the diffusion of adhesive monomers.
Assuntos
Dentina/química , Dentina/efeitos da radiação , Lasers de Estado Sólido , Espectrometria por Raios X/métodos , Animais , Bovinos , Relação Dose-Resposta à Radiação , Incisivo/química , Incisivo/efeitos da radiação , Doses de RadiaçãoRESUMO
AIM: To evaluate, using an experimental immature tooth model, the fracture resistance of bovine incisors submitted to different reinforcement treatments with mineral trioxide aggregate (MTA). METHODOLOGY: An immature tooth model was created by sectioning the coronal and apical portions of 40 bovine incisors 8 mm above and 12 mm below the cementoenamel junction. The root canals were irrigated with 1.0% sodium hypochlorite. They were enlarged both coronally and apically using number 703 carbide burs (ISO: 500-104-168-007-021) and their internal diameter was standardized to 2.1 mm. The specimens were assigned to four groups (n = 10): GI-control (without filling); GII-apical MTA plug + filling with gutta-percha and endodontic sealer; GIII-filling with MTA; GIV-apical MTA plug + filling with MTA + metallic post (Reforpost I). A polyether impression material was used to simulate the periodontal ligament. The specimens were submitted to a compressive load at a crosshead speed of 0.5 mm min(-1) in a servo-hydraulic universal testing machine (MTS 810) applied at 45 degrees to the long axis of the tooth until failure. Data were submitted to statistical analysis by the Kruskal-Wallis test at 5% significance level. RESULTS: GIV presented the highest fracture resistance (32.7N) and differed significantly from the other groups (P < 0.05). No statistically difference was found between GII (16.6N) and GIII (23.4N) (P > 0.05). GIII had a significantly higher fracture resistance than GI (P < 0.05). CONCLUSIONS: The use of MTA + metallic post as an intra-radicular reinforcement treatment increased the resistance to fracture of weakened bovine teeth in an experimental immature tooth model.
Assuntos
Compostos de Alumínio/uso terapêutico , Compostos de Cálcio/uso terapêutico , Incisivo/química , Óxidos/uso terapêutico , Materiais Restauradores do Canal Radicular/uso terapêutico , Silicatos/uso terapêutico , Fraturas dos Dentes , Animais , Bovinos , Força Compressiva , Combinação de Medicamentos , Incisivo/lesões , Modelos Teóricos , Resistência à TraçãoRESUMO
Se presenta un caso de un paciente masculino de 29 años de edad, quien concurrió a la Clínica de Endodoncia, Facultad de Odontología, Baurú, Brasil, para efectuarse un retratamiento endodóntico del incisivo lateral superior izquierdo. Por medio de la evaluación clínica y radiográfica se diagnosticó una perforación radicular lateral a nivel cervical. Radiográficamente, el diente presentaba un perno, tratamiento del conducto radicular con lesión periapical crónica, una perforación lateral con sobreobturación de gutapercha a nivel cervical lateral de la raíz. El tratamiento consistió en la remoción de la gutapercha, retratamiento del conducto radicular y el sellado de la perforación radicular con trióxido mineral agregado (CPM). A los 12 meses la pieza dentaria retornó asintomática y radiográficamente con reparación de los tejidos periodontales en el lugar de la perforación y en la región periapical (AU)
Assuntos
Adulto , Humanos , Masculino , Guta-Percha/química , Doenças Periapicais/diagnóstico , Óxidos/química , Brasil , Incisivo/química , Incisivo/diagnóstico por imagem , Técnica para Retentor IntrarradicularRESUMO
Se presenta un caso de un paciente masculino de 29 años de edad, quien concurrió a la Clínica de Endodoncia, Facultad de Odontología, Baurú, Brasil, para efectuarse un retratamiento endodóntico del incisivo lateral superior izquierdo. Por medio de la evaluación clínica y radiográfica se diagnosticó una perforación radicular lateral a nivel cervical. Radiográficamente, el diente presentaba un perno, tratamiento del conducto radicular con lesión periapical crónica, una perforación lateral con sobreobturación de gutapercha a nivel cervical lateral de la raíz. El tratamiento consistió en la remoción de la gutapercha, retratamiento del conducto radicular y el sellado de la perforación radicular con trióxido mineral agregado (CPM). A los 12 meses la pieza dentaria retornó asintomática y radiográficamente con reparación de los tejidos periodontales en el lugar de la perforación y en la región periapical (AU)