Influence of disinfection with peracetic acid and hypochlorite in dimensional alterations of casts obtained from addition silicone and polyether impressions

Made available in DSpace on 2019-09-12T16:26:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2013Dental impressions disinfection is important to reduce the risk of cross contamination but this process may produce dimensional distortions. Peracetic acid is a disinfectant agent with several favorable characteristics yet underutilized in Dentistry. The aim of this paper is to compare the dimensional stability of casts obtained from addition silicone and polyether impressions that were immersed for 10 minutes in a solution of 0.2% peracetic acid or 1% sodium hypochlorite. Sixty samples in type IV gypsum were produced after a master cast that simulated a full crown preparation of a maxillary premolar. Samples were divided in 6 groups (n = 10) according to the impression material and disinfection agent: Group AC - addition silicone control (without disinfectant); Group APA - addition silicone + 0.2% peracetic acid; Group AH - addition silicone + 1% sodium hypochlorite; Group PC - polyether control (without disinfectant); Group PPA - polyether + 0.2% peracetic acid; Group PH - polyether + 1% sodium hypochlorite. Cast height, base and top diameter were measured and a mean value was obtained for each sample and group all data was statistically analyzed (ANOVA, p < 0.05). There was not a significant statistical difference between addition silicone and polyether impressions regardless of the disinfectant materials. It can be concluded that disinfection with the proposed agents did not produce significant alterations of the impressions and the peracetic acid could be considered a reliable material to disinfect dental molds.Queiroz, D.A., Department of Dentistry, University of Vila Velha, Vila Velha, Espírito Santo, BrazilPeçanha, M.M., Department of Prosthodontics, University Federal of Espirito Santo Vitória, Espírito Santo, BrazilNeves, A.C.C., Department of Prosthodontics, University of Taubaté Taubaté, São Paulo, BrazilFrizzera, F., College of Dentistry at FAESA, Vitória, BrazilTonetto, M.R., Faculty of Dentistry, University of Cuiabá, Cuiabá, Brazilda Silva-Concílio, L.R., Department of Prosthesis, University of Taubaté, Taubaté São Paulo, Brazi

Influence of acquisition parameters on the evaluation of mandibular third molars through cone beam computed tomography

CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORThe aim of the study was to assess the influence of cone beam computed tomography (CBCT) acquisition parameters on the evaluation of mandibular third molars and their relationship to the mandibular canal. Eight dry human mandibles with 13 mandibular third1242183190CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORsem informaçã

Characterization of Isomeric Cationic Porphyrins with β-Pyrrolic Substituents by Electrospray Mass Spectrometry: The Singular Behavior of a Potential Virus Photoinactivator

Electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MS/MS) have been used to differentiate the 2- and 4-methylpyridyl isomers of free-base and metallated cationic β-vinylpyridylporphyrins. The analysis by ESI-MS/MS of the deuterated analogs and semiempirical calculations of structural and electronic parameters were also undertaken. The two free-base isomers are easily differentiated by ESI-MS/MS but the presence of a metallic center renders differentiation of the metallated isomers less effective. The data acquired show that of all the studied compounds, the free-base 2-methylpyridyl isomer, which was operative in the in vitro photoinactivation of Herpes simples virus, has a different gas-phase behavior. Local distortion of the macrocycle due to the presence of the β-vinylpyridyl substituent occurs for all the compounds, but a different electron density distribution can account for the observed gas-phase behavior of this potential virus photoinactivator