Effects of light-curing time on the cytotoxicity of a restorative composite resin on odontoblast-like cells

This in vitro study evaluated the cytotoxicity of an experimental restorative composite resin subjected to different light-curing regimens. METHODS: Forty round-shaped specimens were prepared and randomly assigned to four experimental groups (n=10), as follows: in Group 1, no light-curing; in Groups 2, 3 and 4, the composite resin specimens were light-cured for 20, 40 or 60 s, respectively. In Group 5, filter paper discs soaked in 5 µL PBS were used as negative controls. The resin specimens and paper discs were placed in wells of 24-well plates in which the odontoblast-like cells MDPC-23 (30,000 cells/cm²) were plated and incubated in a humidified incubator with 5% CO2 and 95% air at 37ºC for 72 h. The cytotoxicity was evaluated by the cell metabolism (MTT assay) and cell morphology (SEM). The data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (p<0.05). RESULTS: In G1, cell metabolism decreased by 86.2%, indicating a severe cytotoxicity of the non-light-cured composite resin. On the other hand, cell metabolism decreased by only 13.3% and 13.5% in G2 and G3, respectively. No cytotoxic effects were observed in G4 and G5. In G1, only a few round-shaped cells with short processes on their cytoplasmic membrane were observed. In the other experimental groups as well as in control group, a number of spindle-shaped cells with long cytoplasmic processes were found. CONCLUSION: Regardless of the photoactivation time used in the present investigation, the experimental composite resin presented mild to no toxic effects to the odontoblast-like MDPC-23 cells. However, intense cytotoxic effects occurred when no light-curing was performed.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

9-year follow-up of uncommon cleft palate in Aarskog-Scott syndrome

Aarskog-Scott syndrome (AAS) is characterized by different facial, skeletal and genital anomalies and may have oral manifestations. A 7-year-old boy was referred to the University General Hospital for treatment of speech difficulties and frequent regurgitation. Characteristics such as a triangle-shaped face, hypertelorism, low-set ears, flattened nose, shawl scrotum and partial syndactylia on hands and feet were observed. Based on these clinical features, the child was diagnosed with AAS. Upon intraoral examination, maxillary atresia and an incomplete cleft palate were observed. The mixed dentition was characterized by extensive coronary destruction of primary teeth and caries lesions on permanent teeth. Here, the case of a 9-year follow-up of this child with uncommon AAS associated with cleft palate is reported. The child was referred to a multidisciplinary team for planning and carrying out the treatment. In the follow-up visit after 9 years from the beginning of the treatment, the child showed greater sociability, with significant improvement in spontaneous speech and pronunciation of phonemes. However, the patient continues until now with articulation and spontaneous speech training. The correction of class II malocclusion, better dental alignment and canine extrusion were achieved. At the moment, the patient uses a nighttime extraoral device, and the treatment continues for dental alignment and prevention of tooth decay. The presence of cleft palate could be coincidental with AAS and may aggravate the prognosis, requiring careful patient monitoring by a multiprofessional team

Can different stages of leprosy treatment influence the profile of oral health? Oral status in leprosy

The aim of study was to evaluate the oral health status, salivary flow and halitosis among individuals diagnosed with leprosy as compared with healthy subjects. A sample of 160 individuals was allocated into four groups, as follows: (G1) individuals with complete leprosy treatment; (G2) individuals diagnosed with leprosy and under multi-drug therapy; (G3) individuals diagnosed with leprosy not yet under treatment; and (G4) healthy individuals. Then individuals were submitted to periodontal clinical examination (visible plaque index, bleeding index, depth of probing and clinical attachment level); DMFT index (decayed-missing-filled teeth index); evaluation of salivary flow and halitosis using a halimeter equipment (Interscan Corp, Chatsworth, CA, USA). The data were analyzed using Kruskal-Wallis and chi-square tests. The mean DMFT was found to be higher than 6.6, which is considered very high, with no significant difference between groups (P>0.05). As for salivary flow, 76.2% of the subjects presented normal flow rates, while 10% and 13.7% showed low and very low salivary flow rates, respectively, with hyposalivation being mostly observed in Groups 1 and 2. The highest prevalence of noticeable odor was found in healthy individuals (G4), and the most prevalent periodontal diagnosis was gingivitis (63.1%) in Group 3 (individuals with leprosy not yet under multi-drug therapy) followed by periodontitis (25%) in Group 1 (individuals who had completed leprosy treatment). It was observed that individuals with a history of leprosy present poor oral health similar to that of systemically healthy individuals

Effects of Brown and Green Propolis on Bond Strength of Fiberglass Posts to Root Canal Dentin

Introduction: The purpose of this study was to evaluate the effect of brown and green propolis on bond strength of the fiberglass posts to root canal dentin, and to compare it with conventional endodontic irrigants. Methods and Materials: Sixty bovine teeth were selected, decoronated and randomly distributed into six groups (n=10), according to the irrigation solution: 0.9% saline solution (Control); 2% chlorhexidine (CHX); 5% malic acid (MA); 0.5% ethanolic extract of brown propolis (BP); 0.25% ethanolic extract of green propolis (GP); 2.5% sodium hypochlorite (NaOCl). After root canal treatment, fiber posts were cemented into prepared root canals with a self-adhesive resin cement. The roots were cross-sectioned to obtain two discs from each third and submitted to the micro push-out test. Failure patterns were evaluated under optical microscopy. The influence of irrigants agents was analyzed using one-way ANOVA followed by Games-Howell’s test (α=0.05). Failure modes were analyzed using Fischer’s exact test (α=0.05). Results: There were statistically significant differences among the groups (P&lt;0.05). The control, NaOCl and BP groups showed the highest bond strength with no statistically significant difference between them (P&gt;0.05). Adhesive failure type was the predominant in all groups. Conclusion: Based on this in vitro study, the use of 0.5% brown propolis did not influence the bond strength of fiberglass posts to root canal dentin, while the use of 0.25% green propolis did affect it negatively

Physicomechanical Properties of Tertiary Monoblock in Endodontics: A Systematic Review and Meta-analysis

Introduction: A systematic review and meta-analysis were conducted to evaluate the physicomechanical properties of tertiary monoblock obturation with different obturation techniques. Methods and Materials: PubMed (MEDLINE), Web of Science, Scopus, the Cochrane Library, LILACS, IBECS, and BBO were searched time. PICO question was: “In extracted human teeth (Population), does tertiary monoblock obturation (Intervention) have superior physicomechanical properties (Outcome) compared to conventional obturation systems (Comparison)?”. Statistical analyses for push-out bond strength were performed with RevMan software by comparing the mean differences of each study, with a 95% confidence interval. Inverse variance was used as statistical method, random-effects models as analysis model, and heterogeneity between studies was assessed by Cochran’s Q test and I2 statistic (P &lt;0.05). Results: Of 2162 studies retrieved, 31 were included in this review for “Study Characteristics”. Ten studies were included in the meta-analysis. Analysis demonstrated that conventional obturation had significantly higher push-out bond strength than tertiary monoblock obturation (P &lt;0 .01), with a mean difference of −1.00 (95% CI, −1.41 to −0.58; I2=100%). Subgroups using single-cone and cold lateral condensation techniques showed significantly lower push-out bond strength for tertiary monoblock obturation (P &lt;0.01), respectively with a mean difference of −0.09 (95% CI, −1.13 to −0.67; I2=97%) and of −1.97 (95% CI, −3.19 to −0.75; I2=100%). The warm vertical compaction subgroup showed no statistically significant difference between tertiary monoblock and conventional systems (P =0.13), with a mean difference of 0.49 (95% CI, −0.14 to 1.12; I2=10%). Conclusion: Tertiary monoblock systems have a push-out bond strength similar to conventional systems when used with warm vertical compaction

Pleomorphic ademona of minor salivary glands in uncommon sites: a case series

Pleomorphic adenoma (AP) is the most common tumor of the salivary glands, classified as a benign mixed tumor with the involvement of epithelial, myoepithelial and mesenchymal components. This type of tumor affects primarily affects the parotid glands, with a small percentage of cases involving minor salivary glands. In this study, two cases of PA with unusual location, palate and upper lip are presented. The clinical and histopathological characteristics of the tumors as well as the therapeutic management adopted are discussed.O adenoma pleomórfico (AP) é o tumor mais comum das glândulas salivares, sendo classificado como um tumor benigno de natureza mista, com participação de componentes epiteliais, mioepiteliais e mesenquimais. Este tipo de tumor afeta primariamente as glândulas parótidas, sendo que apenas uma pequena parcela dos casos apresenta envolvimento das glândulas salivares menores. Neste estudo, são apresentados dois casos de AP com localizações atípicas: palato e lábio superior. As características clínicas e histopatológicas dos tumores, bem como os manejos terapêuticos adotados são discutidas

Efeito do tempo de fotoativação na citotoxicidade de cimentos de ionômero de vidro modificados por resina em células de linhagem odontoblástica

O objetivo deste estudo foi avaliar a citotoxicidade in vitro de cimentos de ionômero de vidro modificados por resina para forramento, quando submetidos a diferentes tempos de fotoativação, utilizando cultura de células imortalizadas de linhagem odontoblástica (MDPC-23). Foram confeccionados 40 espécimes de cada material experimental (Fuji Lining LC e Vitrebond). Filtros de papel embebidos com 5æL de PBS ou com 5æL de HEMA puro foram usados como controle negativo e positivo (n = 10), respectivamente. Quatro diferentes tempos de fotoativação foram avaliados: ausência de fotoativação, metade do tempo recomendado pelo fabricante (15s), tempo recomendado pelo fabricante (30s) e uma vez e meia o tempo recomendado pelo fabricante (45s). Os espécimes foram posicionados em compartimentos de recipientes plásticos para cultura de células e, 1 mL do meio de cultura DMEM suplementado, contendo cerca de 3 X 104 células MDPC-23/cm2 foi introduzido em cada um dos mesmos. Em seguida, estes foram mantidos por 72 horas em estufa com 100% de umidade à 37ºC, com 5% de CO2 e 95% de ar. A citotoxicidade foi avaliada por meio do teste de viabilidade celular (teste do MTT) e da análise da morfologia celular pela microscopia eletrônica de varredura. A análise estatística determinou que o Fuji Lining LC apresentou menor citotoxicidade que o Vitrebond (p<0,05) e ambos os materiais proporcionaram uma redução no metabolismo celular de 9,3% e 80,7%, respectivamente. A citotoxicidade do Fuji Lining LC aumentou acentuadamente na ausência de irradiação pela luz, entretanto o mesmo não foi observado para o Vitrebond. O tempo de fotoativação não exerceu influência na toxicidade de ambos os cimentos para forramento quando estes foram aplicados sobre a cultura de células da linhagem odontoblástica- MDPC-23.The aim of this in vitro study was to evaluate the cytotoxicity of resin-modified glass-ionomer lining cements submitted to different light-curing times, applied to an immortalized odontoblast-cell line. Forty round-shaped specimens of each experimental material (Fuji Lining LC and Vitrebond) were prepared. Sterilized filter papers soaked with either 5æL of PBS or 5æL of pure HEMA were used as negative and positive control (n = 10), respectively. Four different light-curing times were evaluated: no light activation, light activation for half of the time recommended by the manufactures (15s), manufacturersþ recommended time (30s) and light activation for 1.5 times the manufacturersþ recommended time (45s). The specimens were placed into wells of 24-well dishes and odontoblast-like cells MDPC-23 were plated at 3 X 104 cells/cm2 in each well. Culture medium (DMEM) with 10% of fetal bovine serum, supplemented with penicillin, streptomycin and glutamine was used. Finally, the well dishes were maintained for 72 hours in a humidified incubator at 37ºC, with 5% of CO2 and 95% air. The cytotoxicity was evaluated by the test of cellular viability, Methyltetrazolium assay (MTT) and the cell morphology was assessed using a scanning electron microscope (SEM). The statistical analysis determined that Fuji Lining LC was less cytotoxic than Vitrebond (p <0,05) and both materials provided a reduction in the cellular metabolism of 9,3% and 80,7%, respectively. The cytotoxicity of Fuji Lining LC remarkably increased in the absence of light activation, while the same was not observed for Vitrebond. The length of light curing (15s, 30s and 45s) did not influence the toxicity of both lining materials when applied on a odontoblast-cell line-MDPC-23.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Potencial angiogênico de células pulpares humanas em hipóxia

Luxações dentárias resultam em injúrias ao feixe vásculo-nervoso, o que pode causar redução significante no nível de oxigênio das polpas dentárias, ou mesmo morte deste tecido conjuntivo especializado. O conhecimento dos mecanismos envolvidos na resposta das células pulpares à hipóxia pode melhorar o prognóstico dos tratamentos das luxações dentárias. O objetivo deste trabalho foi avaliar o comportamento de células-tronco (DPSC) e de fibroblastos (HDPF) de polpas dentárias humanas em condições de hipóxia e a capacidade destas em estimular a proliferação e formação de tubos capilares por células endoteliais microvasculares dérmicas humanas (HDMEC). As análises do western blot e imunocitoquímica foram realizadas para avaliar o efeito da hipóxia na ativação do fator de transcrição induzido pela hipóxia 1 (HIF-1alfa). A expressão dos fatores de crescimento vascular endotelial (VEGF) e fibroblástico básico (bFGF) foi avaliada pelos testes de imunoensaio ELISA. O efeito do HIF-1alfa na expressão do VEGF foi avaliado pelo tratamento das células DPSC e HDPF com 40 μM YC-1, inibidor do HIF-1alfa. Para a avaliação da angiogênese in vitro, os testes de proliferação celular (WST-1) e de formação de tubos capilares em gel de colágeno foram realizados após tratamento das células HDMEC com os meios de acondicionamento das células DPSC ou HDPF, em condições de normóxia ou hipóxia.. A análise dos dados obtidos foi realizada por testes estatísticos não-paramétricos com nível de significância de 5%. Aumento da atividade do HIF-1alfa e da expressão de VEGF foram observados nas células DPSC e HDPF em condições de hipóxia. Entretanto, não foram observadas alterações nos níveis de expressão de bFGF. A expressão do HIF-1alfa foi inibida...Dental luxations can result in the severing of the dental pulp and the creation of a hypoxic environment that might lead to the death of the pulp tissue. Improved understanding of the mechanisms underlying the response of dental pulp cells to hypoxic conditions might lead to better treatment of dental luxations. The purpose of this work was to evaluate the behavior of Dental Pulp Stem Cells (DPSC) and Human Dental Pulp Fibroblasts (HDPF) under hypoxia and their ability to stimulate proliferation and sprouting of endothelial cells. Western blots and immunohistochemistry were used to evaluate the effect of hypoxia on the activation of the transcriptional factor HIF-1α. Vascular Endothelial Growth Factor (VEGF) and Basic Fibroblastic Growth Factor (bFGF) expression was evaluated by ELISA. The effect of HIF-1αon VEGF expression was evaluated by treating DPSC or HDPF with 40 μM YC-1, an inhibitor of HIF-1α. To evaluate the angiogenic potential of dental pulp cells in vitro, human dermal microvascular endothelial cells (HDMEC) were treated with conditioned medium from DPSC or HDPF in normoxia or hypoxia. Sprouting and WST-1 assays were used to evaluate capillaries tubes-like formation and cell proliferation rate,respectively. The statistic analysis was performed by non-parametric tests. HIF-1αactivity and VEGF expression were up-regulated in DPSC and HDPF under hypoxic conditions. However, no changes in the expression levels of bFGF were observed. YC-1 40μM was able to inhibit HIF-1alpha in both cell lines and it also reduced VEGF expression in DPSCs in hypoxia. HDPF under hypoxia increased HDMEC sprouting by 50% when compared to HDPF in normoxia, and by 30% when compared to DPSC in hypoxia. Notably, HDPF under hypoxia stimulated HDMEC proliferation by 30% when compared to DPSC in hypoxia. It was concluded... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES