RESUMEN
This paper aimed to assess the influence of adhesive restoration interface on the diffusion of hydrogen peroxide (H2O2), indirect toxicity, and pro-inflammatory mediators expression by odontoblast-like cells, after in-office tooth whitening. Dental cavities prepared in bovine enamel/dentin discs were adhesively restored and subjected or not to hydrolytic degradation (HD). A whitening gel with 35% H2O2 (WG) was applied for 45 min onto restored and non-restored specimens adapted to artificial pulp chambers giving rise to the groups: SD- intact discs (control); SD/HP- whitened intact discs; RT/HP- restored and whitened discs; and RT/HD/HP- restored and whitened discs subjected to HD. The extracts (culture medium + WG components diffused through enamel/dentin/restoration interface) were collected and applied to odontoblast-like MDPC-23 cells. The study evaluated the amount of H2O2 in the extracts, as well as the cell viability (CV), cell morphology (CM), and gene expression of inflammatory mediators (TNF-α and COX-2) by the pulp cells exposed to the extracts (ANOVA and Tukey tests; 5% significance). All whitened groups presented lower CV than SD (control; p<0.05). The highest CV reduction and gene expression of TNF-α and COX-2 was observed in the RT/HD/HP group in comparison with SD/HP and RT/HP (control; p<0.05). CM alterations occurred in all whitened groups. The intensity of these cell side effects was directly related with the amount of H2O2 in the extracts. We concluded that adhesive restoration of dental cavity increases the H2O2 diffusion after in-office whitening, enhancing the indirect toxicity of this therapy and trigger pro-inflammatory overexpression by MDPC-23 cells.
Asunto(s)
Blanqueadores Dentales , Blanqueamiento de Dientes , Animales , Bovinos , Ciclooxigenasa 2 , Esmalte Dental , Peróxido de Hidrógeno/toxicidad , Mediadores de Inflamación , Blanqueadores Dentales/toxicidad , Factor de Necrosis Tumoral alfaRESUMEN
Abstract This paper aimed to assess the influence of adhesive restoration interface on the diffusion of hydrogen peroxide (H2O2), indirect toxicity, and pro-inflammatory mediators expression by odontoblast-like cells, after in-office tooth whitening. Dental cavities prepared in bovine enamel/dentin discs were adhesively restored and subjected or not to hydrolytic degradation (HD). A whitening gel with 35% H2O2 (WG) was applied for 45 min onto restored and non-restored specimens adapted to artificial pulp chambers giving rise to the groups: SD- intact discs (control); SD/HP- whitened intact discs; RT/HP- restored and whitened discs; and RT/HD/HP- restored and whitened discs subjected to HD. The extracts (culture medium + WG components diffused through enamel/dentin/restoration interface) were collected and applied to odontoblast-like MDPC-23 cells. The study evaluated the amount of H2O2 in the extracts, as well as the cell viability (CV), cell morphology (CM), and gene expression of inflammatory mediators (TNF-α and COX-2) by the pulp cells exposed to the extracts (ANOVA and Tukey tests; 5% significance). All whitened groups presented lower CV than SD (control; p<0.05). The highest CV reduction and gene expression of TNF-α and COX-2 was observed in the RT/HD/HP group in comparison with SD/HP and RT/HP (control; p<0.05). CM alterations occurred in all whitened groups. The intensity of these cell side effects was directly related with the amount of H2O2 in the extracts. We concluded that adhesive restoration of dental cavity increases the H2O2 diffusion after in-office whitening, enhancing the indirect toxicity of this therapy and trigger pro-inflammatory overexpression by MDPC-23 cells.
Resumo Este trabalho teve como objetivo avaliar a influência da interface de uma restauração adesiva na difusão do peróxido de hidrogênio (H2O2), toxicidade indireta e expressão de mediadores pró-inflamatórios por células odontoblastóides, após clareamento dental em consultório. Cavidades dentárias preparadas em discos de esmalte / dentina foram restauradas com adesivo e submetidas ou não à degradação hidrolítica (HD). Um gel clareador com 35% H2O2 (WG) foi aplicado por 45 min em discos restaurados e não restaurados adaptados às câmaras pulpares artificiais dando origem aos grupos: SD- discos intactos (controle); SD / HP - Discos intactos clareados; RT / HP - discos restaurados e clareados; e RT / HD / HP - discos restaurados, clareados e submetidos a HD. Os extratos (meio de cultura + componentes WG difundidos através da interface esmalte/dentina/restauração) foram coletados e aplicados em células odontoblastóides MDPC-23. Foi avaliada a quantidade de H2O2 nos extratos, bem como a viabilidade (CV), morfologia (CM) e expressão gênica de mediadores inflamatórios (TNF-α e COX-2) pelas células pulpares expostas aos extratos (ANOVA e testes de Tukey; 5% de significância). Todos os grupos clareados apresentaram menor CV do que SD (controle; p <0,05). A maior redução CV e expressão gênica de TNF-α e COX-2 foi observada no grupo RT / HD / HP em comparação com SD / HP e RT / HP (controle; p <0,05). Alterações na CM ocorreram em todos os grupos clareados. A intensidade desses efeitos celulares teve relação direta com a quantidade de H2O2 nos extratos. Concluímos que a presença de uma cavidade contendo restauração adesiva aumenta a difusão de H2O2 após o clareamento em consultório, o que, por sua vez, aumenta a toxicidade indireta dessa terapia e desencadeia a expressão de mediadores pró-inflamatórios pelas células pulpares MDPC-23.
RESUMEN
BACKGROUND: Sleep bruxism (SB) is a masticatory muscle activity that affects children. Parents' knowledge is important for its identification and report to dentists. AIM: To investigate parents' knowledge about SB among their children. DESIGN: A cross-sectional study included 1325 parents of children from dental clinics of seven institutions from all regions of Brazil. Parents answered questions about child's sleep, knowledge about SB and its occurrence among children and parents. SB definition given by parents was dichotomized as "correct"/"incorrect", based on the American Academy of Sleep Medicine definition. Descriptive, bivariate and multivariate analyses were performed (P < 0.05). RESULTS: Most parents (57.3%) did not know what SB is and 88.9% would like to receive more information. SB prevalence among parents was 15.4% and 24.0% among children. Between parents who correctly defined SB, its prevalence increased to 27.5% among parents and 40.6% among children. Parents whose children had/have SB, who would like to receive more information about SB and were from the North, Central-West, Southeast, and South regions were more likely to define SB correctly (P > 0.05). CONCLUSION: There is a lack of knowledge of parents about SB. SB among children, parents' interest in receiving more information and their location were factors associated to their knowledge.
Asunto(s)
Bruxismo del Sueño , Brasil , Cuidadores , Niño , Estudios Transversales , Humanos , Padres , Encuestas y CuestionariosRESUMEN
Oral mucositis (OM) is the most common debilitating complication among patients undergoing hematopoietic stem cell transplantation (HSCT). Photobiomodulation therapy (PBM) has shown beneficial effects in the treatment of OM, but few studies have evaluated its biological effects. This study evaluated the effect of PBM on the reduction of OM severity in patients undergoing HSCT and its relation to the modulation of the inflammatory response. Fifty-one patients were randomly assigned to two groups: PBM [submitted to PBM from admission (AD) to D+7] (n = 27) and control (n = 24) [received oral hygiene]. OM severity was assessed daily using the WHO scale. Saliva samples were collected on AD, D+7, and hospital discharge (HD) to measure CXCL8/interleukin 8, using cytometric bead array analysis and nitrite (NO) and myeloperoxidase (MPO) using colorimetric methods. PBM significantly reduced the severity of OM from D+7 to D+11 (p < 0.05). All non-interventional patients (controls) who developed grade 2 or higher OM induced an increase of CXCL8 in saliva (n = 14) on D+7. PBM led to a decrease in CXCL8 on D+7 in 85% of patients, while 70.8% of patients in the control group presented an increase in this chemokine (p = 0.007). NO decreased from AD to D+7 in the PBM group (p > 0.05). MPO significantly decreased on D+7 in both groups (p < 0.05). PBM brought about a reduction in the severity of OM in patients undergoing HSCT, and this reduction was associated with a decrease in CXCL8 salivary levels.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Interleucina-8/metabolismo , Terapia por Luz de Baja Intensidad/métodos , Nitritos/metabolismo , Peroxidasa/metabolismo , Saliva/metabolismo , Índice de Severidad de la Enfermedad , Estomatitis/inducido químicamente , Estomatitis/metabolismo , Adulto , Femenino , Humanos , Mediadores de Inflamación/metabolismo , Masculino , Estomatitis/patologíaRESUMEN
OBJECTIVE: The aim of this study was to assess the impact of low-level laser therapy (LLLT) on oral mucositis (OM) and quality of life (QoL) of hematopoietic stem cell transplantation (HSCT) patients. BACKGROUND DATA: OM related to high-dose chemotherapy is often associated with increased risk of mortality and impaired QoL in HSCT patients. LLLT has shown promising effects in the prevention and treatment of chemotherapy-induced OM. There is a dearth of literature focused on subjective aspects involving OM and QoL in patients receiving LLLT. METHODS: Thirty-nine patients were randomly assigned to two groups: control (n=19) and laser (n=20). LLLT was performed from the 1st day of the conditioning regimen until day 7 post-HSCT (D+7). OM severity was evaluated in all patients [World Health Organization (WHO) scale]. A blinded observer collected subjective outcomes from patients on admission (AD), D+7 and at discharge (DC). QoL was assessed using the Oral Health Impact Profile (OHIP-14) and the Functional Assessment of Cancer Therapy-Bone Marrow Transplantation (FACT-BMT) questionnaires. Statistical analyses included descriptive, bivariate and multivariate (generalized estimating equation) tests. RESULTS: The overall FACT-BMT (p=0.074) and OHIP-14 (p=0.749) scores were not associated with the use of laser therapy. Both instruments showed a deterioration in QoL for the whole sample on D+7. The laser group presented less severe OM than the control group (p<0.001). CONCLUSIONS: LLLT did not influence the oral and general health-related QoL of patients undergoing HSCT, although it was clinically effective in reducing the severity of chemotherapy-induced OM.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Leucemia/terapia , Terapia por Luz de Baja Intensidad , Linfoma/terapia , Calidad de Vida , Estomatitis/radioterapia , Adolescente , Adulto , Método Doble Ciego , Femenino , Humanos , Leucemia/complicaciones , Linfoma/complicaciones , Masculino , Persona de Mediana Edad , Salud Bucal , Estomatitis/etiología , Encuestas y Cuestionarios , Adulto JovenRESUMEN
OBJECTIVES: To evaluate the short-term response of human pulps to ethanol-wet bonding technique. METHODS: Deep class V cavities were prepared on 17 sound premolars and divided into three groups. After acid-etching, the cavities from groups 1 (G1) and 2 (G2) were filled with 100% ethanol or distilled water, respectively, for 60 s before the application of Single Bond 2. In group 3 (G3, control), the cavity floor was lined with calcium hydroxide before etching and bonding. All cavities were restored with resin composite. Two teeth were used as intact control. The teeth were extracted 48h after the clinical procedures. From each tooth serial sections were obtained and stained with haematoxylin and eosin (H/E) and Masson's trichrome. Bacteria microleakage was assessed using Brown & Brenn. All sections were blindly evaluated for five histological features. RESULTS: Mean remaining dentine thickness was 463±65µm (G1); 425±184µm (G2); and 348±194µm (G3). Similar pulp reactions followed ethanol- or water-wet bonding techniques. Slight inflammatory responses and disruption of the odontoblast layer related to the cavity floor were seen in all groups. Stained bacteria were not detected in any cavities. Normal pulp tissue was observed in G3 except for one case. CONCLUSIONS: After 48h, ethanol-wet bonding does not increase pulpal damage compared to water-wet bonding technique. CLINICAL SIGNIFICANCE: Ethanol-wet bonding may increase resin-dentine bond durability. This study reported the in vivo response of human pulp tissue when 100% ethanol was applied previously to an etch-and-rinse simplified adhesive system.
Asunto(s)
Recubrimiento Dental Adhesivo/métodos , Preparación de la Cavidad Dental , Pulpa Dental/efectos de los fármacos , Recubrimientos Dentinarios/farmacología , Etanol/farmacología , Adolescente , Diente Premolar , Materiales Biocompatibles/uso terapéutico , Recubrimiento de la Cavidad Dental , Filtración Dental/microbiología , Pulpa Dental/microbiología , Pulpa Dental/patología , Pulpa Dental/ultraestructura , Exposición de la Pulpa Dental/terapia , Dentina/microbiología , Dentina/ultraestructura , Recubrimientos Dentinarios/química , Etanol/química , Humanos , Odontoblastos/patologíaRESUMEN
Patients undergoing hematopoietic stem cell transplantation (HSCT) are submitted to a conditioning regimen of high-dose chemotherapy, with or without radiation therapy, which usually results in oral ulcerations and mucosal barrier breakdown. Oral mucositis (OM) is a common and debilitating toxicity side effect of autologous and allogeneic HSCT. The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on the severity of OM and inflammatory mediator (TNF-α, IL-6, IL-1ß, IL-10, TGF-ß, metalloproteinases, and growth factors) levels in saliva and blood of HSCT patients. Thirty patients were randomly assigned to two groups: control (n = 15) and laser (n = 15). LLLT was applied from the first day of the conditioning regimen until day 7 post-HSCT (D + 7). Saliva and blood were collected from patients on admission (AD), D-1, D + 3, D + 7, and on marrow engraftment day (ME). Clinical results showed less severe OM in the laser group (p < 0.05). The LLLT group showed increased matrix metalloproteinase 2 (MMP-2) levels in saliva on D + 7 (p = 0.04). Significant differences were also observed for IL-10 on D + 7 and on ME in blood plasma, when compared to the control group (p < 0.05). No significant differences were seen in saliva or blood for the other inflammatory mediators investigated. LLLT was clinically effective in reducing the severity of chemotherapy-induced OM in HSCT patients, and its mechanism of action does not seem to be completely linked to the modulation of pro- or anti-inflammatory cytokines, growth factors or matrix metalloproteinases.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Láseres de Semiconductores/uso terapéutico , Terapia por Luz de Baja Intensidad , Estomatitis/radioterapia , Acondicionamiento Pretrasplante/efectos adversos , Adulto , Femenino , Humanos , Mediadores de Inflamación/metabolismo , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Leucemia/terapia , Linfoma/terapia , Masculino , Metaloproteinasa 2 de la Matriz/metabolismo , Persona de Mediana Edad , Agonistas Mieloablativos/efectos adversos , Saliva/enzimología , Estomatitis/inducido químicamente , Estomatitis/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Adulto JovenRESUMEN
OBJECTIVE: This study aimed to evaluate HLA-G expression in primary oral cavity squamous cell carcinoma (OCSCC) and potentially malignant lesions and to evaluate its relationship with clinicopathologic parameters. STUDY DESIGN: HLA-G expression in samples from patients with metastatic and nonmetastatic OCSCC (n = 60), potentially malignant lesions (n = 15), and clinically and histologically normal oral mucosa (n = 10) was characterized by immunohistochemistry. The density of CD8, CD83, and CD68 cells and Ki-67(+) and bcl-2(+) neoplastic cells were analyzed. RESULTS: HLA-G expression by neoplastic cells was significantly higher in metastatic OCSCC compared with nonmetastatic OCSCC (P = .01). Higher HLA-G expression was observed in OCSCC than in potentially malignant lesions (P = .006). Moreover, patients with lower HLA-G expression exhibited a tendency toward longer survival (22 months) compared with those with higher HLA-G expression (16 months). CONCLUSIONS: Our findings suggest that increased HLA-G expression in metastatic OCSCC may represent a tumor escape mechanism, which portends an unfavorable clinical prognosis.
Asunto(s)
Antígenos de Neoplasias/inmunología , Carcinoma de Células Escamosas/inmunología , Antígenos HLA-G/inmunología , Neoplasias de la Boca/inmunología , Antígenos de Neoplasias/metabolismo , Carcinoma de Células Escamosas/patología , Femenino , Antígenos HLA-G/metabolismo , Humanos , Inmunohistoquímica , Metástasis Linfática , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/patología , Clasificación del Tumor , Invasividad Neoplásica , Estadificación de Neoplasias , Fotomicrografía , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
The aim of this study was to compare the effect of a 16% carbamide peroxide (CP) gel and a 10% CP gel on mineralized enamel content and morphology. Enamel blocks from bovine incisors were subjected to a 14-day treatment (8 h/day) with 10% or 16% CP gels. Knoop microhardness was evaluated before bleaching and at 1, 7 or 14 days after this treatment (50 g/15 s). Mineral content (energy-dispersive x-ray spectroscopy), surface roughness and topography (atomic force microscopy) were evaluated at the 14-day period. Data were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). Significant microhardness reduction was observed at the 7 th and 14 th days for 10% CP gel, and for all bleaching times for 16% CP gel (p<0.05). At the 14-day period, a significant decrease in Ca and P content, increase on surface roughness (p<0.05) as well as on picks and valleys distance were observed when both bleaching gels were used. These enamel alterations were more intense for 16% CP gel. It was concluded that both CP-based gels promoted loss of mineral structure from enamel, resulting in a rough and porous surface. However, 16% CP gel caused the most intense adverse effects on enamel.
O objetivo do presente estudo foi comparar o efeito de um gel com 16% de peróxido de carbamida (PC) sobre a estrutura mineral e morfologia do esmalte dental com os efeitos de um gel com 10% de PC. Blocos de esmalte provenientes de incisivos bovinos foram submetidos a 14 dias de tratamento (8 h/dia) com géis com 10 ou 16% de PC. A microdureza Knoop foi avaliada antes do clareamento e 1, 7 e 14 dias pós-tratamento (50 g/15 s). O conteúdo mineral (EDX), rugosidade de superfície e topografia (MFA) foram avaliados no período de 14 dias (ANOVA a dois critérios e teste de Tukey; α=0,05). Redução significante na microdureza foi observada nos períodos de 7 e 14 dias para o gel com 10% de PC, e em todos os períodos para o gel com 16% de PC (p<0,05). No período de 14 dias, uma diminuição significante no conteúdo de Ca e P, aumento na rugosidade de superfície (p<0,05), bem como na distância entre picos e vales foram observados para ambos os agentes clareadores usados. Estas alterações foram mais intensas para o gel com 16% de PC. Pôde-se concluir que ambos os géis à base de PC promoveram perda de estrutura mineral do esmalte, resultando em superfície mais rugosa e porosa. Porém, o gel com 16% de PC causou efeitos adversos mais intensos no esmalte dental.
Asunto(s)
Humanos , Esmalte Dental/efectos de los fármacos , Peróxidos/efectos adversos , Blanqueamiento de Dientes/métodos , Desmineralización Dental/inducido químicamente , Urea/análogos & derivados , Geles , Pruebas de Dureza , Microscopía de Fuerza Atómica , Peróxidos/administración & dosificación , Espectrometría por Rayos X , Urea/administración & dosificación , Urea/efectos adversosRESUMEN
The aim of this study was to evaluate the possibility of fluoride solutions applied to enamel to protect pulp cells against the trans-enamel and transdentinal cytotoxicity of a 16% carbamide peroxide (CP) bleaching gel. The CP gel was applied to enamel/dentin discs adapted to aicial pulp chambers (8 h/day) during 1, 7 or 14 days, followed by fluoride (0.05% or 0.2%) application for 1 min. The extracts (culture medium in contact with dentin) were applied to MDPC-23 cells for 1 h, and cell metabolism (MTT assay), alkaline phosphatase (ALP) activity and cell membrane damage (flow cytometry) were analyzed. Knoop microhardness of enamel was also evaluated. Data were analyzed statistically by ANOVA and Kruskal-Wallis tests (α=0.05). For the MTT assay and ALP activity, significant reductions between the control and the bleached groups were observed (p<0.05). No statistically significant difference occurred among bleached groups (p>0.05), regardless of fluoride application or treatment days. Flow cytometry analysis demonstrated 30% of cell membrane damage in all bleached groups. After 14 days of treatment, the fluoride-treated enamel presented significantly higher microhardness values than the bleached-only group (p<0.05). It was concluded that, regardless of the increase in enamel hardness due to the application of fluoride solutions, the treated enamel surface did not prevent the toxic effects caused by the 16% CP gel to odontoblast-like cells.
Asunto(s)
Esmalte Dental/efectos de los fármacos , Pulpa Dental/efectos de los fármacos , Fluoruros/farmacología , Peróxidos/toxicidad , Sustancias Protectoras/farmacología , Blanqueadores Dentales/toxicidad , Urea/análogos & derivados , Fosfatasa Alcalina/efectos de los fármacos , Animales , Peróxido de Carbamida , Bovinos , Línea Celular , Membrana Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colorantes , Pulpa Dental/citología , Cavidad Pulpar/efectos de los fármacos , Dentina/efectos de los fármacos , Dureza , Odontoblastos/efectos de los fármacos , Odontoblastos/metabolismo , Propidio , Succinato Deshidrogenasa/efectos de los fármacos , Factores de Tiempo , Urea/toxicidadRESUMEN
The aim of this study was to evaluate the possibility of fluoride solutions applied to enamel to protect pulp cells against the trans-enamel and transdentinal cytotoxicity of a 16% carbamide peroxide (CP) bleaching gel. The CP gel was applied to enamel/dentin discs adapted to aicial pulp chambers (8 h/day) during 1, 7 or 14 days, followed by fluoride (0.05% or 0.2%) application for 1 min. The extracts (culture medium in contact with dentin) were applied to MDPC-23 cells for 1 h, and cell metabolism (MTT assay), alkaline phosphatase (ALP) activity and cell membrane damage (flow cytometry) were analyzed. Knoop microhardness of enamel was also evaluated. Data were analyzed statistically by ANOVA and Kruskal-Wallis tests (α=0.05). For the MTT assay and ALP activity, significant reductions between the control and the bleached groups were observed (p<0.05). No statistically significant difference occurred among bleached groups (p>0.05), regardless of fluoride application or treatment days. Flow cytometry analysis demonstrated 30% of cell membrane damage in all bleached groups. After 14 days of treatment, the fluoride-treated enamel presented significantly higher microhardness values than the bleached-only group (p<0.05). It was concluded that, regardless of the increase in enamel hardness due to the application of fluoride solutions, the treated enamel surface did not prevent the toxic effects caused by the 16% CP gel to odontoblast-like cells.
Resumo O objetivo do presente estudo foi avaliar o possível efeito protetor de soluções fluoretadas aplicadas sobre o esmalte dentário frente à citotoxicidade trans-amelodentinária de um gel clareador com 16% de peróxido de carbamida (PC). O gel de PC foi aplicado sobre discos de esmalte/dentina adaptados a câmaras pulpares aiciais (8 h/dia) durante períodos de 1, 7 ou 14 dias, seguido de aplicação de soluções fluoretadas (0,05% ou 0,2%) durante 1 min. Os extratos (meio de cultura em contato com a dentina) foram aplicados sobre células MDPC-23 durante 1 h, seguido de análise do metabolismo celular (teste do MTT), atividade de fosfatase alcalina (ALP) e danos à membrana celular (citometria de fluxo). A microdureza Knoop do esmalte dental foi avaliada. Os dados foram analisados pelos testes de ANOVA e Kruskal-Wallis. Para o teste do MTT e atividade de ALP, redução significante entre os grupos controle e clareados foram observados (p<0,05). Nenhuma diferença entre os grupos clareados foi observada (p>0,05), independente da aplicação das soluções fluoretadas ou tempo de tratamento. A análise por citometria de fluxo demonstrou lesão à membrana celular em torno de 30% para todos os grupos clareados. Após 14 dias de tratamento, os espécimes clareados e fluoretados apresentaram aumento significante na microdureza do esmalte (p<0,05). Pôde-se concluir que apesar do aumento na dureza do esmalte decorrente da aplicação das soluções fluoretadas, este tratamento não preveniu os efeitos tóxicos causados pelo gel com 16% de PC sobre as células odontoblastóides. .
Asunto(s)
Animales , Bovinos , Esmalte Dental/efectos de los fármacos , Pulpa Dental/efectos de los fármacos , Fluoruros/farmacología , Peróxidos/toxicidad , Sustancias Protectoras/farmacología , Blanqueadores Dentales/toxicidad , Urea/análogos & derivados , Fosfatasa Alcalina/efectos de los fármacos , Línea Celular , Membrana Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colorantes , Cavidad Pulpar/efectos de los fármacos , Pulpa Dental/citología , Dentina/efectos de los fármacos , Dureza , Odontoblastos/efectos de los fármacos , Odontoblastos/metabolismo , Propidio , Succinato Deshidrogenasa/efectos de los fármacos , Factores de Tiempo , Urea/toxicidadRESUMEN
BACKGROUND: bleaching has been widely studied, mainly due to the possible undesirable effects that can be caused by this esthetic procedure. The cytotoxicity of the bleaching agents and its components to pulp cells has been demonstrated in several researches. The aim of this study was to evaluate the toxic effects of successive applications of 10% carbamide peroxide (CP) gel on odontoblast-like cells. MATERIALS AND METHODS: Enamel-dentin discs obtained from bovine incisors were adapted to artificial pulp chambers (APCs). The groups were formed as follows: G1: Without treatment (control group); G2: 10% carbamide peroxide, CP (five applications/one per day); G3: 10% CP (one unique application); and G4: 35% hydrogen peroxide, HP (three applications of 15 min each). After treatment, cell metabolism (MTT), alkaline phosphatase (ALP) activity and plasma membrane damage (flow cytometry) were analyzed. RESULTS: Reductions in cell metabolism and alkaline phosphatase activity along with severe damage of the cytoplasmic membrane were noted in G2. In G3, no damage was observed, compared to the control group. Intermediary values of toxicity were obtained after 35% HP application. CONCLUSION: It can be concluded that one application of 10% CP did not cause toxic effects in odontoblast-like cells, but the successive application of this product promoted severe cytotoxic effects. The daily application of the bleaching agents, such as used in the at-home bleaching technique, can increase the damages caused by this treatment to the dental pulp cells.
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Odontoblastos/efectos de los fármacos , Peróxidos/toxicidad , Urea/análogos & derivados , Fosfatasa Alcalina/metabolismo , Peróxido de Carbamida , Línea Celular , Humanos , Odontoblastos/enzimología , Peróxidos/administración & dosificación , Urea/administración & dosificación , Urea/toxicidadRESUMEN
The aim of this study was to compare the effect of a 16% carbamide peroxide (CP) gel and a 10% CP gel on mineralized enamel content and morphology. Enamel blocks from bovine incisors were subjected to a 14-day treatment (8 h/day) with 10% or 16% CP gels. Knoop microhardness was evaluated before bleaching and at 1, 7 or 14 days after this treatment (50 g/15 s). Mineral content (energy-dispersive x-ray spectroscopy), surface roughness and topography (atomic force microscopy) were evaluated at the 14-day period. Data were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). Significant microhardness reduction was observed at the 7 th and 14 th days for 10% CP gel, and for all bleaching times for 16% CP gel (p<0.05). At the 14-day period, a significant decrease in Ca and P content, increase on surface roughness (p<0.05) as well as on picks and valleys distance were observed when both bleaching gels were used. These enamel alterations were more intense for 16% CP gel. It was concluded that both CP-based gels promoted loss of mineral structure from enamel, resulting in a rough and porous surface. However, 16% CP gel caused the most intense adverse effects on enamel.
Asunto(s)
Esmalte Dental/efectos de los fármacos , Peróxidos/efectos adversos , Blanqueamiento de Dientes/métodos , Desmineralización Dental/inducido químicamente , Urea/análogos & derivados , Peróxido de Carbamida , Geles , Pruebas de Dureza , Humanos , Microscopía de Fuerza Atómica , Peróxidos/administración & dosificación , Espectrometría por Rayos X , Urea/administración & dosificación , Urea/efectos adversosRESUMEN
OBJECTIVES: To evaluate: (1) the in vitro antibacterial, cytotoxic and mechanical properties of a resin-modified glass ionomer cement (RMGIC) containing different concentrations of chlorhexidine (CHX) and (2) the in vivo microbiologic action of the best concentration of CHX associated with the RMGIC applied on remaining dentine after indirect pulp treatment (IPT). METHODS: For the in vitro studies, RMGIC was associated with 0.2, 0.5, 1.25 and 2.5% CHX. Microbiologic evaluation consisted of an agar diffusion test on cariogenic bacteria for 24h. Odontoblast-like cell metabolism and morphology analyses measured the cytotoxic effects of the RMGIC groups after 24h. The same groups were submitted to compressive and diametral tensile strength. The in vivo treatment consisted of IPT using an RMGIC associated with the best CHX concentration. Clinical and microbiologic evaluations were performed before and after 3 months. RESULTS: The use of 1.25% CHX significantly improved the antibacterial effects of the evaluated RMGIC, without causing any detrimental effects to the odontoblast-like cells and on the mechanical properties. This RMGIC and CHX combination completely eliminated mutans streptococci after 3 months of IPT. CONCLUSION: The RMGIC and 1.25% CHX mixture showed great biological and mechanical behaviour and could be a good treatment against caries progression. CLINICAL SIGNIFICANCE: The association of CHX with a liner RMGIC opens a new perspective for arresting residual caries after IPT.
Asunto(s)
Antiinfecciosos Locales/química , Clorhexidina/análogos & derivados , Cementos de Ionómero Vítreo/química , Cementos de Resina/química , Actinomyces/efectos de los fármacos , Antiinfecciosos Locales/farmacología , Antiinfecciosos Locales/toxicidad , Técnicas de Cultivo de Célula , Línea Celular , Forma de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Niño , Preescolar , Clorhexidina/química , Clorhexidina/farmacología , Clorhexidina/toxicidad , Colorantes , Fuerza Compresiva , Caries Dental/microbiología , Caries Dental/terapia , Recubrimiento de la Cavidad Dental/métodos , Dentina/efectos de los fármacos , Dentina/microbiología , Dentina/patología , Cementos de Ionómero Vítreo/farmacología , Cementos de Ionómero Vítreo/toxicidad , Humanos , Lactobacillus acidophilus/efectos de los fármacos , Ensayo de Materiales , Fenómenos Mecánicos , Viabilidad Microbiana/efectos de los fármacos , Microscopía Electrónica de Rastreo , Odontoblastos/efectos de los fármacos , Cementos de Resina/farmacología , Cementos de Resina/toxicidad , Streptococcus mutans/efectos de los fármacos , Estrés Mecánico , Resistencia a la Tracción , Sales de Tetrazolio , Tiazoles , Factores de TiempoRESUMEN
O objetivo do estudo foi avaliar a citotoxicidade trans-amelodentinária de um gel clareador com 35% de H2O2 aplicado sobre dentes com ou sem restauração de resina composta e submetidos ou não a procedimento de envelhecimento. Cavidades preparadas em discos de esmalte/dentina obtidos de dentes bovinos íntegros foram restauradas com sistema adesivo autocondicionante e resina composta. Os discos foram armazenados em solução aquosa por 24 horas ou 6 meses e o procedimento de termociclagem foi realizado somente nos grupos armazenados por 6 meses. Os discos foram posicionados em câmaras pulpares artificiais e distribuídos em grupos: Íntegros 24 horas; Íntegros 24 horas clareados; Íntegros 6 meses; Íntegros 6 meses clareados; Restaurados 24 horas; Restaurados 24 horas clareados; Restaurados 6 meses; e Restaurados 6 meses clareados. O gel clareador foi aplicado sobre os discos por 15 minutos (1 aplicação) ou por 45 minutos (3 aplicações consecutivas de 15 minutos cada), sendo que os extratos (meio de cultura em contato com a dentina + componentes dos gel clareador que se difundiram através dos discos) foram recolhidos e aplicados por 1 hora sobre células odontoblastóides MDPC-23 em cultura (12.500 células/cm2). Para o experimento no qual o gel clareador foi aplicado somente uma vez, observouse redução significativa do metabolismo celular apenas para o grupo de dentes restaurados quando comparado ao controle (íntegros 24 horas não clareados) e ao grupo restaurado não clareado, independente do tempo de armazenamento (Tukey, p<0,05). Quando o gel clareador foi aplicado por três vezes consecutivas, houve diminuição do metabolismo celular estatisticamente significante em todos os grupos clareados (Mann-Whitney, p<0,05), sendo observadas intensas alterações morfológicas das células MDPC-23. Entretanto, não houve diferença com relação a presença de restauração e o tempo... (Resumo completo, clicar acesso eletrônico abaixo).
The aim of this in vitro study was to evaluate the trans-enamel and transdentinal cytotoxic effects of a 35% hydrogen peroxide (H2O2) bleaching gel applied on non-restored or restored teeth, submitted or not to aging by water storage and thermocycling. Enamel/dentin discs were obtained from bovine central incisors and restored or not with self-etching adhesive system and composite resin. These discs were storage in water for 24 hours or 6 months (aging). Thus, the discs were adapted individually in artificial pulp chambers and distributed according to the following treatments: non-restored teeth stored for 24 hours submitted or not to bleaching procedures; non-restored teeth stored for 6 months submitted or not to bleaching procedures; restored teeth stored for 24 hours submitted or not to bleaching procedures; and restored teeth stored for 6 months submitted or not to bleaching procedures. The bleaching gel was left in contact with the enamel surface for 15 minutes (1 application) or for 45 minutes (3 applications of 15 minutes each). The extracts (culture medium in contact to the dentin surface of the discs + bleaching agents components that diffused across the discs) were collected and applied on previously cultured MDPC-23 cells (12.500 cells/cm2) for 1 hour. Cell metabolism was evaluated by the MTT assay and cell morphology by scanning electron microscopy. One application of bleaching gel in the enamel surface of the discs caused a significant decrease in cell metabolism only in the restored discs in comparison with control discs (unbleached and non-restored discs stored for 24 hours) and unbleached restored discs, regardlles of the storage time (Tukey, p<0.05). On the other hand, bleaching agent applied for three consecutive times on enamel caused a significant decreased in cell metabolism in all bleached discs (Mann- Whitney, p<0.05). However, there were no differences between... (Complete abstract click electronic access below).
Asunto(s)
Peróxido de Hidrógeno , Odontoblastos , Blanqueamiento de DientesRESUMEN
Atualmente, a busca incessante por dentes brancos tem levado muitos pacientes a realizar técnicas de clareamento dentário de forma indiscriminada. O clareamento é muito utilizado na Odontologia Estética por ser considerada uma técnica supostamente não invasiva. Entretanto, os possiveis danos causados pelos componentes dos agentes clareadores sobre as estruturas dentais não estão totalmente elucidados. Diversos efeitos deletérios têm sido relacionados ao uso abusivo dos agentes clareadores, tais como alterações na superfície do esmalte e de materiais restauradores, os quais favorecem a penetração de componentes tóxicos em direção à câmara pulpar, podendo causar sensibilidade dentinária e danos significativos à polpa. Além disso, o clareamento dental pode estar associado ao processo de reabsorção radicular cervical no caso de clareamento de dentes não-vitais. Diante das diversas técnicas existentes, torna-se um desafio para os clinicos selecionar o método de clareamento mais eficaz e que, ao mesmo tempo, não cause danos ao paciente. Portanto, o objetivo dessa revisão de literatura foi abordar os tipos de técnicas disponíveis, o mecanismo de ação dos agentes clareadores e os fatores que podem influenciar nesse mecanismo. Também foram abordados os possíveis efeitos negativos que podem acontecer quando da realização do clareamento de dentes vitais e de dentes não-vitais.
Nowadays, the search for improving the aesthetics of the natural dentition has driven clinicians and patients to use different bleaching techniques indiscriminately. Bleaching has been suggested as an efficient and conservative approach for discolored teeth. However, the biologi- cal effects of this treatment are not fully understood. Some adverse effects have been reported due to the abusive application of tooth bleaching agents, such as surface alterations of enamel and restorative materiais. These alterations facilitate the diffusion of toxic components of the bleaching agents through enamel and dentin, towards the pulp, which may result in post- treatment hypersensitivity and intense pulpal damage. Moreover, the bleaching of non-vital teeth has been associated to external cervical resorption. Due to the different bleaching tech- niques currently available, clinicians are faced with the challenge of selecting the most effective tooth-whitening systems, which should be able to promote the best esthetic results without causing pain or damage to the tooth structures. Therefore, the aim of this literature review was to analyze the currently available bleaching techniques, the mechanism of action of the bleach- ing agents and the factors that may influence this mechanism of action. Moreover, the possible adverse effects caused by the bleaching of vital and non-vital teeth were discussed.
Asunto(s)
Humanos , Masculino , Femenino , Blanqueamiento de Dientes/métodos , Odontoblastos , Peróxido de Hidrógeno/uso terapéuticoRESUMEN
Objetivo: avaliar a citotoxicidade trans-amelodentinária de um gel clareador com 100/0 de peróxido de carbamida (PC) sobre células odontoblastóides MDPC-23. Materiais e Métodos: Discos de esmalte/ dentina, obtidos de incisivos bovinos, foram adaptados em câmaras pulpares artificiais. O gel clareador em estudo foi aplicado por 8 horas diárias sobre a superfície de esmalte, pelos períodos de 1,7 ou 14 dias. Os extratos (meio de cultura contendo os produtos do gel clareador que se difundiram através do esmalte e dentina) foram aplicados por 1 hora sobre as células MDPC-23 previamente cultivadas. Meio de cultura puro foi utilizado como grupo controle. O metabolismo celular (teste de MTI) e a morfologia das células (MEV) pós-clareamento foram avaliados. Os dados obtidos foram estatisticamente analisados (Anova um critério e teste de Tukey; a=5%). Resultados: Não foi observada diferença estatisticamente significante entre o grupo controle e os grupos experimentais (p>O,051, sendo que nenhuma diferença estatisticamente significante ocorreu quando se comparou os diferentes períodos de aplicação do gel clareador (1,7 ou 14 dias) entre si (p>O,05). Conclusão: De acordo com a metodologia empregada na presente pesquisa, foi possível concluir que o gel clareador com 10% de PC não causou efeito citotóxico significante para as células MDPC-23, independente do número de aplicações do produto sobre a estrutura dental.
Aim: The purpose of this in vitro study was to evaluate the trans-enamel and trans-dentinal cytotoxic effects of a 10% carbamide peroxide bleaching on MDPC-23 cells, applied for different periods on the enamel surface. Material and Methods: Enameljdentin discs obtained from bovine incisors were adapted to artificial pulp charnbers Bleaching gel with 10% carbamide peroxide was applied for 8 hours daily on the enamel surface, for the periods of 1,7 or 14 days. The extracts (culture medium + products of bleach- ing gel that reached the pulpal space) were applied for 1 hour on previously cultured MDPC-23 cells. Cell metabolism and cell morphology were evaluated by MTI assay and SEM, respectivelv The data obtained from MTI assay were analyzed statistically (a=5%; One way anova; Tukey's testl Results: There was no statistically significant difference between control group and experimental groups submitted to bleaching procedures (p>0.05). There was not also significant difference among the different periods of gel applica- tion (1,7 or 14 days) (p>0.05). Conclusion: According to the methodology employed in this in vitro study, it was possible to conclude that the bleaching gel with 10% carbamide peroxide caused no significant cytotoxic effect to MDPC-23 cells, regardless the number of applications on the enamel surface.
Asunto(s)
Animales , Bovinos , Blanqueamiento de Dientes/métodos , Odontoblastos , Toxicidad/efectos adversosRESUMEN
OBJECTIVE: To evaluate and compare the responses of human incisor and premolar pulps after bleaching. STUDY DESIGN: A bleaching agent with 38% hydrogen peroxide (H(2)O(2)) was applied on the buccal surface of 10 sound lower teeth (G1: 6 premolars; G2: 4 incisors) for 45 minutes. Three premolars and 3 incisors that received only rubber/pumice prophylaxis were used as control groups G3 and G4, respectively. Two days after the bleaching procedure, the teeth were extracted and processed for histologic evaluation. RESULTS: Only in G2 (4 incisors) were any changes in the pulp detected. In the coronal pulp there was a large zone of coagulation necrosis. The radicular pulp showed mild inflammatory changes manifested as an accumulation of mononuclear cells around congested and dilated blood vessels. No pulpal damage was seen in either of the control groups (G3 and G4) or in group G1. CONCLUSION: Bleaching with 38% H(2)O(2) for 45 minutes causes irreversible pulp damage in lower incisors but not in premolars.
Asunto(s)
Pulpa Dental/efectos de los fármacos , Peróxido de Hidrógeno/uso terapéutico , Oxidantes/uso terapéutico , Blanqueamiento de Dientes/métodos , Adolescente , Diente Premolar/efectos de los fármacos , Profilaxis Dental , Pulpa Dental/irrigación sanguínea , Pulpa Dental/patología , Necrosis de la Pulpa Dental/inducido químicamente , Necrosis de la Pulpa Dental/patología , Dentina/efectos de los fármacos , Dentina/patología , Dentina Secundaria/inducido químicamente , Dentina Secundaria/patología , Humanos , Peróxido de Hidrógeno/administración & dosificación , Hiperemia/inducido químicamente , Hiperemia/patología , Incisivo/efectos de los fármacos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/patología , Neutrófilos/efectos de los fármacos , Neutrófilos/patología , Odontoblastos/efectos de los fármacos , Odontoblastos/patología , Oxidantes/administración & dosificación , Pulpitis/inducido químicamente , Pulpitis/patología , Factores de TiempoRESUMEN
OBJECTIVE: This study evaluated transenamel and transdentinal cytotoxic effects of a bleaching gel on the MDPC-23 cell line. STUDY DESIGN: Discs obtained from bovine incisors were placed in a metallic device to simulate an in vivo pulp chamber. Groups were formed according to the enamel surface treatment: G1: 35% H(2)O(2) bleaching gel; G2: 35% H(2)O(2) bleaching gel + halogen light; G3: halogen light; and G4: control. Cell metabolism was evaluated by the methyltetrazolium assay and cell morphology by scanning electron microscopy. RESULTS: Cell metabolism decreased by 31.7%, 41.6%, and 11.5% in G1, G2, and G3, respectively. Cytotoxic effects observed in G2 were significantly more severe compared with G3 and G4. In G1 and G2, a smaller number of viable cells with major morphologic alterations remained adhered to dentin. CONCLUSION: The bleaching gel associated with light presented transenamel and transdentinal cytotoxic effects characterised by direct damage to odontoblasts and decrease of their metabolic activity.
Asunto(s)
Peróxido de Hidrógeno/toxicidad , Odontoblastos/efectos de los fármacos , Oxidantes/toxicidad , Blanqueamiento de Dientes , Animales , Bovinos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Colorantes , Esmalte Dental/efectos de los fármacos , Dentina/efectos de los fármacos , Difusión , Geles , Luz , Microscopía Electrónica de Rastreo , Distribución Aleatoria , Sales de Tetrazolio , TiazolesRESUMEN
The aims of this study were to evaluate clinically and microbiologically the effects of two resin-modified glass-ionomer cements (RMGICs) used as liners after incomplete dentine caries removal and to identify Streptococcus mutans and Streptococcus sobrinus strains isolated from dentine samples, before and after indirect pulp treatment. Twenty-seven primary molars with deep carious lesions, but without signs and symptoms of irreversible pulpitis, were submitted to indirect pulp treatment. Treatment consisted of incomplete excavation of the carious dentine, application of one of the RMGICs (Vitrebond or Fuji Lining LC) or calcium hydroxide cement (Dycal), and sealing for 3 months. Clinical evaluation (consistency, color, and wetness of dentine) and carious dentine collects were performed before temporary sealing and after the experimental period. Microbiological samples were cultivated in specific media for subsequent counting of mutans streptococci (MS) and lactobacilli (LB). MS colonies were selected for identification of S. mutans and S. sobrinus by polymerase chain reaction. After 3 months, the remaining dentine was hard and dry, and there was a significant decrease in the number of MS and LB, in all groups, although complete elimination was not achieved in 33% and 26% of the teeth for MS and LB, respectively. From 243 MS colonies selected, 216 (88.9%) were identified as S. mutans and only 2 (0.8%) as S. sobrinus. The use of resin-modified glass-ionomer liners after incomplete caries removal, as well as a calcium hydroxide cement, promoted significant reduction of the viable residual cariogenic bacteria in addition to favorable clinical changes in the remaining carious dentine.