The Self-assembling peptide P11-4 influences viability and osteogenic differentiation of stem cells of the apical papilla (SCAP).

OBJECTIVE: To analyze the effect of P11-4 self-assembly peptide on cell viability and osteogenic capacity of SCAPs through mineral deposition and gene expression of osteogenic markers. METHODS: SCAPs were seeded in contact with P11-4 (10 µg/ml, 100 µg/ml and 1 mg/ml) solution. Cell viability was evaluated using a colorimetric assay MTT: 3-(4,5-dimethyl-thiazolyl-2)-2,5- diphenyltetrazolium bromide) in an experimental time of 24, 48 and 72 h (n = 7). Mineral deposition and quantification provided by the cells was tested using the Alizarin Red staining and Cetylpyridinium Chloride (CPC), respectively, after 30 days (n = 4). Gene expression of Runt-related transcription factor 2 (RUNX2), Alkaline phosphatase (ALP) and Osteocalcin (OCN) was quantified using quantitative polymerase chain reaction (RT-qPCR), at 3 and 7 days with Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as the housekeeping gene, and relative gene expression was measured using the ΔΔCq method. Data were analyzed using Kruskall-Wallis followed by multiple comparisons, and T-test for gene expression with α=0.05. RESULTS: All tested concentrations (10 µg/ml, 100 µg/ml and 1 mg/ml) were not cytotoxic at time 24 and 48 h. After 72 h, a slight decrease in cell viability was observed for the lowest concentration (10 µg/ml). The concentration of 100 µg/ml P11-4 showed the highest mineral deposition. However, qPCR analysis of P11-4 (10 µg/ml) showed upregulation of RUNX2 and OCN at 3 days, with downregulation of ALP at 3 and 7d CONCLUSION: P11-4 did not affect cell viability, induced mineral deposition in SCAPs, and upregulated the expression of RUNX2 and OCN genes at 3 days, while downregulating ALP expression at 3 and 7 days. CLINICAL SIGNIFICANCE: Based on the results obtained in this study it can be stated that self-assembling peptide P11-4 is a potential candidate to induce mineralization on dental stem cells for regenerative purposes and also for a clinical use as a capping agent without compromising the cells health.

Avaliação da experiência odontológica prévia, hábitos alimentares e de higiene bucal em pacientes com paralisia cerebral / Evaluation of previous dental experience, eating habits and oral hygiene in patients with cerebral palsy

Avaliar descritivamente a experiência odontológica prévia, práticas de higiene bucal e hábitos alimentares de pacientes com Paralisia Cerebral (PC). Foi realizado um estudo observacional, do tipo transversal, com pacientes diagnosticados com PC através uma amostra de conveniência (n=27), com idade entre 3 e 14 anos, de ambos os sexos, que buscaram atendimento no ambulatório de pediatria do Hospital Universitário Materno Infantil, em São Luís ­ MA, no período de julho a outubro de 2018. Foi aplicado um questionário estruturado ao cuidador contendo história médica e odontológica da criança, avaliando também as práticas de higiene bucal e hábitos alimentares. Verificou-se que 66.67% dos pacientes eram do sexo masculino, com média de idade de 8,5 anos. Todos os acompanhantes eram do sexo feminino e a maior parte apresentou baixa escolaridade. Dentro os participantes, 92,59% não apresentavam habilidade para realizar escovação dentária e 51,85% dos cuidadores nunca receberam orientação sobre os cuidados de higiene bucal; 70,37% dos participantes fazem o consumo de alimentos açucarados e pastosos, e mais da metade já tiveram experiência de cárie. O estudo mostrou deficiência na higienização e um alto consumo de açúcar. Nesse sentido, práticas de higiene bucal e instruções dietéticas devem ser reforçadas e orientadas aos cuidadores a fim de contribuir para melhor assistência e prevenção à saúde.

Descriptively evaluate the previous dental experience, oral hygiene practices and eating habits of patients with Cerebral Palsy (CP). An observational, cross-sectional study was carried out with patients diagnosed with CP through a convenience sample (n = 27), aged between 0 and 18 years, of both sexes, who sought care at the pediatric outpatient clinic of Materno Infantile University Hospital, at Federal University of Maranhão, in São Luís - MA, from July to October 2018. A structured questionnaire was applied to the caregiver containing the child's medical and dental history, also evaluating oral hygiene practices and eating habits. It was found that 66.67% of the patients were male, with a mean age of 8.5 years. All companions were female and most had low education. Within the participants, 92.59% did not have the ability to perform tooth brushing and 51.85% of the caregivers never received guidance on oral hygiene care; 70.37% of participants consume sugary and pasty foods, and more than half have had caries experience. The study showed poor hygiene and a high consumption of sugar. In this sense, oral hygiene practices and dietary instructions should be reinforced and oriented to caregivers in order to contribute to better health care and prevention.