RESUMO
This study aimed to evaluate the effect of desensitizing and conventional mouth rinses on dentin tubule occlusion. Dentin hypersensitivity was simulated by EDTA application for five minutes. The specimens were randomly allocated into the following groups: desensitizing mouth rinses (Colgate Sensitive, Elmex Sensitive Professional, Listerine Advanced Defense Sensitive, Sensodyne Cool Mint); conventional mouth rinses (Colgate Plax, Elmex Caries Protection, Listerine Anticaries, Sensodyne Pronamel); a negative control (C-: distilled water); and Clinpro XT Varnish was the positive control (C+). Subsequently, the specimens were submitted to an erosive or abrasive challenge (performed separately) and to an erosive/abrasive cycling for five days (n=10 for each challenge). After treatment, challenges, and cycling, the specimens were analyzed in an environmental scanning electron microscope to verify the number of open dentin tubules (ODTs), counted by using Image J software (National Institutes of Health, Bethesda, MD, USA). Data were analyzed by the Kruskal-Wallis, Friedman and Dunn tests, with Bonferroni correction (α=0.05). Groups did not differ at baseline (p>0.05). At the post-treatment, erosion and abrasion stages, C+ was the only group that showed a reduction in ODTs compared to C-(p<0.05). In the other groups, numbers did not differ significantly from C- (p>0.05). After cycling, none of the groups exhibited significant reduction in ODTs other than C- (p>0.05); however, C+, Listerine Anticaries, and Colgate Plax had a lower number of ODTs than Listerine Sensitive and Sensodyne Pronamel. No mouth rinse was able to promote significant occlusion of the dentin tubules after treatment and the challenges. C+ was the only product that effectively promoted tubular occlusion, but this effect did not withstand several erosive and abrasive challenges.
Assuntos
Dessensibilizantes Dentinários , Benzoatos , Dentina , Dessensibilizantes Dentinários/farmacologia , Dessensibilizantes Dentinários/uso terapêutico , Diaminas , Ácido Edético , Fluoretos , Microscopia Eletrônica de Varredura , Antissépticos Bucais/farmacologia , Antissépticos Bucais/uso terapêutico , Dodecilsulfato de Sódio , Fluoreto de Sódio , ÁguaRESUMO
BACKGROUND: Port-Wine Stains (PWS) are vascular malformations of the dermis, whereas hemangiomas are vascular tumors usually present at birth. Early non-invasive diagnosis of the vascular lesion would greatly increase treatment efficiency. We propose to use optical coherence tomography (OCT), a morphological imaging technique, coupled with functional blood-flow Doppler modality. METHODS: We imaged lesions from five patients: one with PWS, four with hemangiomas, using a Thorlabs Swept-Source OCT system at 1325 nm. Additional Doppler images allow for distinguishing blood vessels from empty cavities that appear similar on conventional OCT images. RESULTS: We are able to distinguish between normal skin and vascular lesions. The PWS lesion presents blood vessels of mean diameter 114 µm with a standard deviation of 92 µm, and mean depth 304 µm with a standard deviation of 99 µm. The hemangiomas present blood vessels of mean diameter 39 µm with a standard deviation of 19 µm, and mean depth 298 µm with a standard deviation of 133 µm. CONCLUSION: We show a significant difference between the vascular characteristics of the studied PWS and hemangiomas lesions. We believe that OCT complemented by Doppler OCT could be a promising method for future non-invasive diagnosis and monitoring of some vascular lesions.
Assuntos
Hemangioma Capilar/diagnóstico por imagem , Imagem Multimodal/métodos , Mancha Vinho do Porto/diagnóstico por imagem , Pele/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Ultrassonografia Doppler/métodos , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
In this study, a comprehensive investigation on the temperature increase at the light guide tip of several commercial light-emitting diode (LED) light-curing units (LCUs) and the associated thermal variation (ΔT) at the pulpal floor of dental cavities was carried out. In total, 15 LEDs from all generations were investigated, testing a quartz-tungsten-halogen (QTH) unit as a reference. The irradiance level was measured with a power meter, and spectral distribution was analyzed using a spectrometer. Temperature increase at the tip was measured with a type-K thermocouple connected to a thermometer, while ΔT at the pulpal floor was measured by an infrared photodetector in class V cavities, with a 1-mm-thick dentin pulpal floor. The relationship among measured irradiance, ΔT at the tip, and ΔT at the pulpal floor was investigated using regression analyses. Large discrepancies between the expected and measured irradiances were detected for some LCUs. Most of the LCUs showed an emission spectrum narrower than the QTH unit, with emission peaks usually between 450 and 470 nm. The temperature increase at the tip followed a logarithmic growth for LCUs with irradiance ≥1000 mW/cm(2), with ΔT at the tip following the measured irradiance linearly (R(2)=0.67). Linear temperature increase at the pulpal floor over the 40-second exposure time was observed for several LCUs, with linear association between ΔT at the pulpal floor and measured irradiance (R(2)=0.39) or ΔT at the tip (R(2)=0.28). In conclusion, contemporary LED units show varied irradiance levels that affect the temperature increase at the light guide tip and, as a consequence, the thermal variation at the pulpal floor of dental cavities.
Assuntos
Temperatura Corporal/efeitos da radiação , Lâmpadas de Polimerização Dentária/classificação , Preparo da Cavidade Dentária/classificação , Polpa Dentária/efeitos da radiação , Animais , Bovinos , Dentina/efeitos da radiação , Raios Infravermelhos , Doses de Radiação , Radiometria , Análise Espectral , Temperatura , Termografia/métodos , Termômetros , Fatores de TempoRESUMO
This study evaluated the effect of Er,Cr:YSGG laser irradiation and professional fluoride application on enamel demineralization and on fluoride formation and retention. In a blind in vitro study, 264 human enamel slabs were distributed into 8 groups: G1--untreated; G2--treated with acidulated phosphate fluoride gel (APF gel, 1.23% F) for 4 min; G3, G4 and G5--irradiated with Er,Cr:YSGG at 2.8, 5.6 and 8.5 J/cm2, respectively; G6, G7 and G8--preirradiated with Er,Cr:YSGG at 2.8, 5.6 and 8.5 J/cm2, respectively, and subjected to APF gel application. Twenty slabs of each group were submitted to a pH-cycling regimen, and enamel demineralization was evaluated in 10 slabs of each group. In the other 10 slabs, CaF2-like material was determined. To evaluate F formed, 10 additional slabs of each group, not subjected to the pH cycling, were submitted to analysis of CaF2-like material and fluorapatite, while the other 3 slabs of each group were evaluated by scanning electron microscopy. The F content was also measured in all pH-cycling solutions. Laser at 8.5 J/cm2 and APF treatment reduced enamel demineralization compared to the control (p < 0.05), but the combination of these treatments was not more efficient than their isolated effect. A higher concentration of retained CaF2-like material was found in laser groups followed by APF in comparison with the APF gel treatment group. The findings suggest that laser treatment at 8.5 J/cm2 was able to decrease hardness loss, even though no additive effect with APF was observed. In addition, laser treatment increased the formation and retention of CaF2 on dental enamel.
Assuntos
Cariostáticos/uso terapêutico , Esmalte Dentário/efeitos da radiação , Fluoretos/uso terapêutico , Lasers de Estado Sólido/uso terapêutico , Desmineralização do Dente/prevenção & controle , Fluoreto de Fosfato Acidulado/análise , Fluoreto de Fosfato Acidulado/uso terapêutico , Apatitas/análise , Apatitas/efeitos da radiação , Fluoreto de Cálcio/análise , Fluoreto de Cálcio/efeitos da radiação , Cariostáticos/análise , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/ultraestrutura , Fluoretos/análise , Dureza , Humanos , Concentração de Íons de Hidrogênio , Eletrodos Seletivos de Íons , Microscopia Eletrônica de Varredura , Método Simples-Cego , Desmineralização do Dente/metabolismo , Remineralização DentáriaAssuntos
Terapia a Laser/métodos , Estomatite/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/efeitos adversos , Feminino , Fluoruracila/efeitos adversos , Humanos , Raios Infravermelhos , Terapia a Laser/instrumentação , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Projetos Piloto , Estomatite/induzido quimicamente , Resultado do TratamentoRESUMO
Applications of Cu-HyBrID laser (copper laser with Hydrogen Bromide In Discharge) in Dentistry and AFM (atomic force microscopy) evaluations of dental tissues irradiated by laser are seldom reported in the literature. This work presents an AFM investigation of the cross-section of a cavity generated in human dental enamel by laser thermal evaporation using the Cu-HyBrID laser. The results exposed the structural and morphological differences between the fused and non-fused dental enamel, provide qualitative information about the susceptibility of these tissues to abrasive polishing, and revealed the extension of the thermal damage. Quantitative information concerning the wall thickness and the dimensions of the cross-section of non-fused enamel rod were also obtained.
Assuntos
Preparo da Cavidade Dentária/métodos , Esmalte Dentário/cirurgia , Esmalte Dentário/ultraestrutura , Terapia a Laser/métodos , Dente Serotino/cirurgia , Dente Serotino/ultraestrutura , Esmalte Dentário/efeitos da radiação , Humanos , Técnicas In Vitro , LuzRESUMO
Laser irradiation on hard tissue has produced a resistant surface that is likely to prevent caries. In this study, human enamel and dentine were exposed to nanosecond pulsed Nd:YAG laser with energy densities of 20-40 J/cm(2) and pulse width of 6 ns inducing chemical changes in these tissues. Infrared analysis of human dental enamel and dentine was performed using the KBr method (2mg sample/300 mg KBr). A correlation between non-lased and lased spectra was performed that gives an indication of the changes in organic and inorganic compounds after laser-tissue interaction. Spectra of teeth simultaneously show the inorganic and organic parts of the tissue. The principal bands: amide bands A, I, II, and III from the collagen-matrix, phosphate from the mineral content, and carbonate bands were identified. The normalized area of peak versus peak position was determined. Changes of the bands attributed to the collagen matrix were verified after Nd:YAG irradiation. The present results suggest a chemical modification of organic and mineral compounds by laser. The spectral results indicated an alteration in the absorption bands relative to, essentially, organic compounds.
Assuntos
Esmalte Dentário/química , Esmalte Dentário/efeitos da radiação , Dentina/química , Dentina/efeitos da radiação , Lasers/efeitos adversos , Humanos , Espectrofotometria Infravermelho/métodosRESUMO
Evaluation of molar dental restorations on enamel is performed using optical coherence tomography (OCT) with 10 microm resolution. Images of approximately 50 microm failure gaps in the restorations are demonstrated and the OCT images are compared with x-ray and optical microscopy pictures. The results demonstrate the potential of the technique for clinical evaluation of dental restorations.
Assuntos
Esmalte Dentário/patologia , Esmalte Dentário/cirurgia , Desgaste de Restauração Dentária , Análise de Falha de Equipamento/métodos , Interpretação de Imagem Assistida por Computador/métodos , Dente Molar/patologia , Dente Molar/cirurgia , Algoritmos , Diagnóstico Bucal/métodos , Estudos de Viabilidade , Humanos , Técnicas In Vitro , Prognóstico , Resultado do TratamentoRESUMO
Failure of apicectomies is generally attributed to dentine surface permeability as well as to the lack of an adequate marginal sealing of the retrofilling material, which allows the percolation of microorganisms and their products from the root canal system to the periodontal region, thus compromising periapical healing. The purpose of this study was to evaluate dentine and the marginal permeability after apicectomy and surface treatment with 9.6 micro m TEA CO(2) or Er:YAG 2.94 micro m laser irradiation. Sixty-five single rooted human endodontically treated teeth were divided into five experimental groups: group I (control), apicectomy with high speed bur; group II, similar procedure to that of group I, followed by dentinal surface treatment with 9.6 micro m CO(2) laser; group III, similar procedure to group I followed by dentinal surface treatment with Er:YAG laser 2.94 micro m; group IV, apicectomy and surface treatment with CO(2) 9.6 micro m laser; and group V, apicectomy and surface treatment with Er:YAG laser 2.94 micro m. The analysis of methylene blue dye infiltration through the dentinal surface and the retrofilling material demonstrated that the samples from the groups that were irradiated with the lasers showed significantly lower infiltration indexes than the ones from the control group. These results were compatible with the structural morphological changes evidenced through SEM analysis. Samples from groups II and IV (9.6 micro m CO(2)) showed clean smooth surfaces, fusion, and recrystallized dentine distributed homogeneously throughout the irradiated area sealing the dentinal tubules. Samples from groups III and V (Er:YAG 2.94 micro m) also presented clean surfaces, without smear layer, but roughly compatible to the ablationed dentine and without evidence of dentinal tubules. Through the conditions of this study, the Er:YAG 2.94 micro m and the 9.6 micro m CO(2) laser used for root canal resection and dentine surface treatment showed a reduction of permeability to methylene blue dye.
Assuntos
Apicectomia , Permeabilidade da Dentina/efeitos da radiação , Terapia a Laser , Dióxido de Carbono , Corantes/farmacocinética , Dentina/ultraestrutura , Humanos , Incisivo/ultraestrutura , Azul de Metileno/farmacocinéticaRESUMO
The purpose of this study is to evaluate the possibility of using a pulsed Ho:YLF laser for endodontic surgery access, preparation of cavities, etching of dental enamel, and treatment of dental caries. Specimens were irradiated with a prototype of pulsed Ho:YLF laser (2,065 microns). Laser energies in the range of 120-750 mJ per pulse were used. The study of morphological changes on enamel and dentine was conducted on light and scanning electron microscopes. Perforation of approximately 4 mm depth with homogeneous and smooth aspect of its wall surfaces was obtained. There was no carbonization. Irradiation with low energy results in melted and recrystalized surface with small and shallow pits. In accordance with our results the Ho:YLF laser produces surfaces that are white in appearance in contrast to the Nd:YAG modified enamel and dentine surfaces, that were darkened. These are indications that the holmium laser may be useful for dentistry in the future.