RESUMO
OBJECTIVES: The aim of this double-blind, randomized in situ study was to evaluate the erosion-preventive effect of a specific set of CO2 laser parameters, associated or not with fluoride. METHODS: Two hundred forty bovine enamel blocks were prepared for individual palatal appliances (n = 6 samples/appliance). The study had four phases of 5 days each, with ten volunteers and the following treatments: CO2 laser irradiation (L), fluoride treatment (F), combined fluoride and laser treatment (FL), and no treatment, control (C). Laser irradiation was performed at 0.3 J/cm2 (5 µs/226 Hz/10.6 µm) and the fluoride gel contained AmF/NaF (12'500 ppm F-/pH = 4.8-6). For erosive demineralization, the appliances were immersed extra-orally in citric acid (0.05 M/20 min/pH = 2.3) twice daily. Analysis of enamel surface loss was done using a 3D-laser profilometer on 3 days. Additionally, fluoride uptake was quantified and scanning electron microscopies were done. Data were analyzed with repeated measures ANOVA and post hoc pairwise comparisons (α = 0.05). RESULTS: At all analyzing days, both laser groups caused the lowest means of enamel loss, which were also statistically significant lower than C (p < 0.05). At day 5, FL means ± SD (33.6 ± 12.6 µm) were even significantly lower than all other groups (C 67.8 ± 15.4 µm; F 57.5 ± 20.3 µm; L 46.8 ± 14.5 µm). Significantly increased enamel fluoride uptake was observed for both fluoride-containing groups (p < 0.05) at day 1. CONCLUSION: Compared to the control, the CO2 laser irradiation with a specific set of laser parameters (0.3 J/cm2/5 µs/226 Hz) either alone or in combination with a fluoride gel (AmF/NaF) could significantly decrease enamel erosive loss up to 5 days in situ. CLINICAL RELEVANCE: Combined CO2 laser-fluoride treatment has a significant anti-erosive effect.
Assuntos
Dióxido de Carbono , Esmalte Dentário/efeitos da radiação , Erosão Dentária/prevenção & controle , Adulto , Animais , Bovinos , Método Duplo-Cego , Feminino , Humanos , Masculino , Fluoreto de Sódio/uso terapêuticoRESUMO
Aim of the present study was to investigate the neuroprotective effect of dental pulp cells (DPCs) in in vitro models of Alzheimer and Parkinson disease. Primary cultures of hippocampal and ventral mesencephalic neurons were treated for 24 h with amyloid beta (Abeta(1-42)) peptide 1-42 and 6-OHDA, respectively. DPCs isolated from adult rat incisors were previously cultured in tissue culture inserts and added to the neuron cultures 2 days prior to neurotoxin treatment. Cell viability was assessed by the MTT assay. The co-culture with DPCs significantly attenuated 6-OHDA and Abeta(1-42)-induced toxicity in primary cultures of mesencephalic and hippocampal neurons, and lead to an increase in neuronal viability in untreated cultures, suggesting a neurotrophic effect in both models. Furthermore, human dental pulp cells expressed a neuronal phenotype and produced the neurotrophic factors NGF, GDNF, BDNF, and BMP2 shown by microarray screening and antibody staining for the representative proteins. DPCs protected primary neurons in in vitro models of Alzheimer's and Parkinson's disease and can be viewed as possible candidates for studies on cell-based therapy.