Cytotoxicity and Effects of a New Calcium Hydroxide Nanoparticle Material on Production of Reactive Oxygen Species by LPS-Stimulated Dental Pulp Cells

Introduction: The aim of this study was to synthesize and characterize calcium hydroxide (CH) nanoparticles [CH-NP] and compare the cytotoxicity of these materials with that of mineral trioxide aggregate (White MTA) in human dental pulp mesenchymal cells (hDPMCs) stimulated by lipopolysaccharide (LPS). Methods and Materials: The CH-NP were synthesized by the co-precipitation method, and the physical properties were investigated through X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS). LPS-stimulated hDPMCs were placed in contact with different dilutions of culture media previously exposed to CH-NP and white MTA for 24 h. The groups were tested for cell viability by MTT formazan and Alamar Blue assays, the production of nitric oxide (NO) by Griess method and the production of reactive oxygen species (ROS) by means of the fluorescent oxidant-sensing probe 2’,7’-dichlorodihydrofluorescein diacetate (DCFH-DA). Control groups for viability test were maintained in DMEM (not LPS-stimulated). For NO and ROS production, negative control group was cells in DMEM, and positive control was cells stimulated by LPS. The results were statistically analyzed by two-way ANOVA, Tukey’s test and Dunnett’s test (ɑ=0.05). Results: The results showed that the cell viability remained above 50% in all materials, independent of the dilution in MTT formazan and Alamar Blue tests. MTA showed a reduction in NO production at dilutions of 1:4 to 1:32 compared with the positive control group (P<0.05). The tested materials exhibited lower ROS production by DPMCs than that by cells in the positive control group (P<0.05), and similar ROS production to the negative control group (P>0.05). Conclusion: The outcomes of present in vitro study showed that MTA and [CH-NP] were not cytotoxic materials, with MTA closer to the results of control group (DMEM). MTA and [CH-NP] reduced ROS production at basal levels, with MTA inhibiting NO production at higher dilutions

Inibição da atividade de osteoblastos expostos ao ácido zoledrônico

INTRODUCTION: Patients treated with nitrogen-containing bisphosphonates, such as zoledronic acid (ZA), have frequently shown oral bone exposure areas, termed osteonecrosis. In addition, these patients may also present low repair and regeneration potential, mainly after tooth extractions. These side-effects caused by bisphosphonates may be due to their inhibitory effects on oral mucosa and local bone cells. OBJECTIVE: To evaluate the effects of ZA on the mineralization capacity of cultured osteoblasts. MATERIALS AND METHODS: Human immortalized osteoblasts (SaOs-2) were grown in plain culture medium (Dulbecco's Modified Eagle Medium [DMEM] + 10% fetal bovine serum [FBS]) in wells of 24-well plates. After 48-hour incubation, the plain DMEM was replaced by a solution with ZA at 5 µM which was maintained in contact with cells for seven, 14 or 21 days. After these periods, cells were evaluated regarding alkaline phosphatase (ALP) activity and mineral nodule formation (alizarin red). Data were statistically analyzed by Mann-Whitney test, at 5% of significance level. RESULTS: ZA caused significant reduction on ALP activity and mineral nodules formation by cultured osteoblasts in all evaluated periods (p < 0.05). CONCLUSION: These data indicate that ZA causes inhibition on the osteogenic phenotype of cultured human osteoblasts, which, in turn, may reduce bone repair in patients subjected to ZA therapy.INTRODUÇÃO: Pacientes em tratamento com bisfosfonatos, sobretudo com os nitrogenados, como o ácido zoledrônico (AZ), têm apresentado áreas de exposição de tecido ósseo na cavidade oral, caracterizadas como osteonecrose. Essas áreas apresentam limitada capacidade de reparo, principalmente após exodontias. Esses efeitos podem ser resultado do efeito inibitório causado por esse tipo de medicamento sobre as células da mucosa e do tecido ósseo local. OBJETIVO: Avaliar o efeito do AZ sobre a capacidade de mineralização de osteoblastos in vitro. MATERIAIS E MÉTODOS: Foi utilizada uma linhagem celular de osteoblastos humanos (SaOs-2). As células foram cultivadas em meio de cultura completo (Dulbecco's Modified Eagle Medium [DMEM] + 10% de soro fetal bovino [SFB]). Após 48 horas de incubação, o DMEM completo foi substituído por um novo DMEM sem SFB, ao qual foram adicionados 5 µM de AZ. Essa solução foi mantida em contato com as células por sete, 14 ou 21 dias. Após esse período, as células foram avaliadas quanto à atividade de fosfatase alcalina (ALP) e à produção de nódulos de mineralização (alizarin red). Os dados foram submetidos ao teste estatístico de Mann-Whitney, considerando nível de significância de 5%. RESULTADOS: A exposição das células ao AZ causou redução significativa na atividade de ALP e na formação de nódulos mineralizados em todos os períodos avaliados (p < 0,05). CONCLUSÃO: Esses resultados revelam que o AZ causa alteração inibitória no fenótipo osteogênico das células humanas em cultura, o que pode reduzir a capacidade de reparo do tecido ósseo após o contato com esse tipo de medicamento.368371Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Assessment of educational actions on the oral health of adolescents within the Family Health Strategy

OBJECTIVE: to evaluate the actions of education on the oral health of adolescents within the scope of the Family Health Strategy. METHODOLOGY: A questionnaire was applied and a clinical exam conducted evaluating biofilm and gingival inflammation in 80 adolescents before and after interventions. A qualitative study of the brushing technique was also performed on 15 adolescents in the sample. RESULTS: there was an improvement in oral hygiene of adolescents who participated in actions at school and an increase in the number of adolescents who had healthy gums or only mild inflammation in the second test in school groups and home visits. With respect to the consumption of candies, both the weekly group and the school group saw a decrease in candy consumption between the first and second tests. There was an increased frequency of brushing in the school group. CONCLUSION: considering the importance of educational activities observed in this study, the process of training and joint planning of activities among the school staff and health professionals would appear to be important.OBJETIVO: avaliar as ações de educação na saúde bucal de adolescentes dentro da Estratégia de Saúde da Família. METODOLOGIA: foi aplicado um questionário e realizado exame clínico avaliando biofilme e inflamação gengival em 80 adolescentes antes e depois das intervenções. Um estudo qualitativo da técnica de escovação também foi realizado em 15 adolescentes pertencentes à amostra. RESULTADOS: observou-se melhora na higiene oral dos que participaram das ações na escola, aumento no número daqueles que apresentaram gengiva saudável ou inflamação leve no segundo exame nos grupos escola e visita domiciliar. Com relação ao consumo de doces, o grupo semanal e da escola apresentou diminuição entre o 1º e o 2º exames. Houve um aumento na frequência de escovação no grupo escola. CONCLUSÃO: diante da importância das ações educativas verificadas neste estudo, parece-nos importante o processo de capacitação e o planejamento conjunto das ações entre os profissionais da escola e os profissionais de saúde.1841184

Efeito transdentinário do LED em diferentes comprimentos de onda sobre células odontoblastóides

Pesquisas recentes demonstraram que a irradiação transdentinária da polpa pode resultar em aumento na síntese de matriz de dentina e redução na resposta inflamatória local. Entretanto, os mecanismos que regem estes processos permanecem desconhecidos. Assim, o objetivo desta pesquisa foi investigar o efeito transdentinário do LED, em três comprimentos de onda (CO: 455nm, 630nm e 850nm) e duas doses de energia (DE: 4J/cm2 e 25 J/cm2), sobre células odontoblastóides MDPC-23 cultivadas em discos de dentina (molares humanos) com 0,2 mm de espessura. Foram realizadas análises do metabolismo celular (SDH), proteína total (PT) e fosfatase alcalina (ALP), através dos ensaios de MTT, Read Northcote e Ponto Final, respectivamente. O ensaio de RT-PCR foi aplicado para avaliação da expressão dos genes que codificam para colágeno tipo I (Col-1), fibronectina (FN) e fosfatase alcalina (ALP). Além disso, foi realizada a análise da morfologia celular em Microscopia Eletrônica de Varredura (MEV). Para a produção de PT, os resultados não apontaram diferença estatisticamente significante entre os grupos irradiados e controle (Mann-Whitney, p>0,05). Entretanto, para o metabolismo celular, o grupo irradiado com LED no CO de 630 nm, na DE de 25 J/cm2, obteve melhores resultados (aumento de 21,8 %), com diferença significante quando comparado ao grupo controle (Mann-Whitney, p0,05). Na análise por RT-PCR, houve maior expressão de Col-1 para o LED infravermelho na dose de 4 J/cm2. Um maior número de células MDPC-23 com morfologia normal aderidas aos discos de dentina, semelhante ao grupo controle, foi...Several studies have demonstrated that the transdentinal irradiation of dental pulp may increase the dentin matrix synthesis as well as decrease the local inflammatory reaction. However, the mechanisms that regulate these processes remain unknown. Therefore, the objective of this in vitro study was to investigate the transdentinal effect of LED irradiation at three different wavelengths (λ= 455, 630 and 850 nm) and two doses (4J/cm2 and 25 J/cm2) on odontoblast-like cells seeded on 0.2-mm-thick dentin disks obtained from sound human molars. Cell metabolism (MTT), alkaline phosphatase expression (ALP), total protein synthesis, and cell morphology (MEV) were evaluated. The expression of genes that encode for collagen type-1 (Col-1), fibronectin (FN) and alkaline phosphatase (ALP) was analyzed by RT-PCR. For total protein synthesis, the results showed no statistical difference among irradiated and control groups (Mann-Whitney test, p>0.05). However, for cellular metabolism, the group irradiated with 630 nm LED (dose of 25 J/cm2) showed better results (21,8% increase), with significant difference when compared to control group (Mann-Whitney test, p0.05). RT-PCR showed a higher expression of Col- 1 for the infrared LED at a dose of 4 J/cm2. A larger number of MDPC-23 cells with normal morphology adhered to the dentin discs was observed after irradiation with 25 J/cm2 when compared to 4 J/cm2, for all wavelengths evaluated. It may be concluded that LED irradiation was effective for transdentinal cell biostimulation and the cellular response was dose and wavelength-dependent.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Schwartz-Jampel Syndrome: a paediatric dentistry approach

Schwartz-Jampel syndrome (SJS) is a rare recessive disorder characterized mainly by myotonia. As the clinical signs and symptoms are manifested in the oromaxillofacial region, paediatric dentists may be first choice of parents that seek information and assistance to their children. A female patient diagnosed with SJS was brought to our clinic for dental treatment with main complain of difficulty on oral hygiene and mastication due to tooth crowding. The treatment included preventive measures, extraction of a supernumerary tooth and the maxillary primary second molars. Furthermore, the patient was referred to orthodontic treatment for correction of tooth crowding. When dealing with children with confirmed diagnosis of SSJ, paediatric dentists should be understand the need of planning the dental treatment considering the characteristics and possible complications associated with the syndrome in order to reduce the risks to patients, especially when surgical procedures are necessary.A síndrome de Schwartz Jampel (SSJ) é uma desordem autossômica recessiva rara, caracterizada principalmente pela miotonia. Desde que alguns dos sinais clínicos e sintomas são manifestados na região oromaxilofacial, o odontopediatra pode ser o primeiro profissional a se deparar com um paciente portador desta síndrome. Um paciente do sexo feminino diagnosticado com SJS procurou a nossa clínica para tratamento dental com queixa principal de dificuldade na realização da higiene oral e mastigação, devido ao mau posicionamento dentário. O tratamento incluiu medidas preventivas, extração de um dente supranumerário e dos segundos molares decíduos e encaminhamento para tratamento ortodôntico. Quando uma criança possui o diagnóstico confirmado para SSJ, o odontopediatra deve ter conhecimento específico para planejar e realizar o tratamento odontológico de forma adequada, considerando as características da síndrome e as possíveis complicações associadas, a fim de reduzir os riscos ao paciente, especialmente quando procedimentos cirúrgicos são necessários

Zoledronic Acid Inhibits Human Osteoblast Activities.

Bisphosphonates are potent inhibitors of bone resorption. These kinds of drugs, which are used for the treatment of osteolytic diseases, have been associated with the occurrence of oral osteonecrosis, especially in patients over 60 years old. Current studies have demonstrated that the cytotoxic effects of bisphosphonates on osteoblasts play an important role in oral osteonecrosis development. The aim of this study was to evaluate the effect of long-term application of a highly potent bisphosphonate - zoledronic acid (ZA) - on human osteoblasts in vitro. Human osteoblasts (MG63 cell line) were seeded for 72 h in wells of 24-well plates. The Dulbecco's modified Eagle's medium (DMEM) was then replaced by culture medium without fetal bovine serum (FBS), and the cells were incubated for an additional 24 h, after which ZA was added to the DMEM without FBS and incubated in contact with osteoblasts for 7, 14 or 21 days. Cell viability (CV), total protein production (TPP), alkaline phosphatase (ALP) activity, mineral nodule formation (MNF), and gene expression of ALP and osteocalcin (OCN), as well as cell morphology by scanning electronic microscopy, were evaluated. Data were statistically analyzed by Kruskal-Wallis and Mann-Whitney tests, with a significance level of 5%. The cytotoxic effects of ZA on osteoblasts were characterized by reduction of CV, TPP, ALP and MNF production. In addition, ZA MNF caused a decrease in gene expression of ALP and OCN, as well as intense cell morphology alterations. All these negative effects of ZA were concentration and period dependent. Both concentrations of ZA (1 and 5 μM) caused cytotoxic effects to osteoblasts which reduced the production and expression of proteins that play an important role in bone matrix synthesis and mineralization.59534-4

Inhibition of osteoblast activity by zoledronic acid

INTRODUCTION: Patients treated with nitrogen-containing bisphosphonates, such as zoledronic acid (ZA), have frequently shown oral bone exposure areas, termed osteonecrosis. In addition, these patients may also present low repair and regeneration potential, mainly after tooth extractions. These side-effects caused by bisphosphonates may be due to their inhibitory effects on oral mucosa and local bone cells. OBJECTIVE: To evaluate the effects of ZA on the mineralization capacity of cultured osteoblasts. MATERIALS AND METHODS: Human immortalized osteoblasts (SaOs-2) were grown in plain culture medium (Dulbecco's Modified Eagle Medium [DMEM] + 10% fetal bovine serum [FBS]) in wells of 24-well plates. After 48-hour incubation, the plain DMEM was replaced by a solution with ZA at 5 µM which was maintained in contact with cells for seven, 14 or 21 days. After these periods, cells were evaluated regarding alkaline phosphatase (ALP) activity and mineral nodule formation (alizarin red). Data were statistically analyzed by Mann-Whitney test, at 5% of significance level. RESULTS: ZA caused significant reduction on ALP activity and mineral nodules formation by cultured osteoblasts in all evaluated periods (p < 0.05). CONCLUSION: These data indicate that ZA causes inhibition on the osteogenic phenotype of cultured human osteoblasts, which, in turn, may reduce bone repair in patients subjected to ZA therapy.INTRODUÇÃO: Pacientes em tratamento com bisfosfonatos, sobretudo com os nitrogenados, como o ácido zoledrônico (AZ), têm apresentado áreas de exposição de tecido ósseo na cavidade oral, caracterizadas como osteonecrose. Essas áreas apresentam limitada capacidade de reparo, principalmente após exodontias. Esses efeitos podem ser resultado do efeito inibitório causado por esse tipo de medicamento sobre as células da mucosa e do tecido ósseo local. OBJETIVO: Avaliar o efeito do AZ sobre a capacidade de mineralização de osteoblastos in vitro. MATERIAIS E MÉTODOS: Foi utilizada uma linhagem celular de osteoblastos humanos (SaOs-2). As células foram cultivadas em meio de cultura completo (Dulbecco's Modified Eagle Medium [DMEM] + 10% de soro fetal bovino [SFB]). Após 48 horas de incubação, o DMEM completo foi substituído por um novo DMEM sem SFB, ao qual foram adicionados 5 µM de AZ. Essa solução foi mantida em contato com as células por sete, 14 ou 21 dias. Após esse período, as células foram avaliadas quanto à atividade de fosfatase alcalina (ALP) e à produção de nódulos de mineralização (alizarin red). Os dados foram submetidos ao teste estatístico de Mann-Whitney, considerando nível de significância de 5%. RESULTADOS: A exposição das células ao AZ causou redução significativa na atividade de ALP e na formação de nódulos mineralizados em todos os períodos avaliados (p < 0,05). CONCLUSÃO: Esses resultados revelam que o AZ causa alteração inibitória no fenótipo osteogênico das células humanas em cultura, o que pode reduzir a capacidade de reparo do tecido ósseo após o contato com esse tipo de medicamento