title: In Vitro Analysis of Surface Roughness of Acrylic Resin Exposed to the Combined Hygiene Method of Brushing and Immersion in Ricinus communis and Sodium Hypochlorite.
abstract: OBJECTIVE
  To evaluate a solution based on Ricinus communis (Castor oil) for denture cleansing, comparing it to sodium hypochlorite (NaOCl) for the surface roughness of heat-polymerized acrylic resin.
  
  
  METHODS
  Forty polished and unpolished resin specimens (90 × 30 × 4 mm) were evaluated before and after their exposure to protocol hygiene: brushing the specimens with a specific denture brush and mild soap for 3 minutes, three times a day, and immersing them in hygiene solutions (0.25% NaOCl-S1 and 0.5% NaOCl-S2; 10% R. communis-S3; saline-S4: control) for 20 minutes. Surface roughness was evaluated by rugosimeter and scanning electron microscopy (SEM) before and after the protocol. For evaluation of surface roughness, polished and unpolished surfaces were used.
  
  
  RESULTS
  The roughness of the polished surface was not affected by time (p = 0.062), but was affected by solutions (p < 0.0001) and the interaction between factors (p = 0.005). For S1 and S4, the period did not influence the roughness. For S2, there was a change after 7 days, remaining stable after 14 days. For S3, there were changes, and stabilization occurred after 14 days. After 7 and 14 days, S2 and S3 promoted major changes, but after 21 days, there were no differences among solutions, except saline. The unpolished surface was not influenced by factors: period (p = 0.115), solution (p = 0.120), and their interaction (p = 0.382). SEM analysis showed similar results on the evaluation of surface roughness.
  
  
  CONCLUSIONS
  The polished surface of the prosthesis was more susceptible to changes when exposed to hygiene solutions, and although the 0.5% NaOCl solution promoted an increase in the surface roughness compared with the same solution at 0.25% and R. communis at 10%, the values are clinically acceptable.
authors.affiliation: School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Maurício Malheiros
authors.initials: MM
authors.lastname: Badaró
authors.affiliation: School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Marcela Moreira
authors.initials: MM
authors.lastname: Salles
authors.affiliation: School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Carolina Noronha Ferraz
authors.initials: CNF
authors.lastname: de Arruda
authors.affiliation: School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Viviane de Cássia
authors.initials: VC
authors.lastname: Oliveira
authors.affiliation: School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Raphael Freitas
authors.initials: RF
authors.lastname: de Souza
authors.affiliation: School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Helena Freitas Oliveira
authors.initials: HFO
authors.lastname: Paranhos
authors.affiliation: School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Cláudia Helena
authors.initials: CH
authors.lastname: Silva-Lovato
mesh_terms: D000180:Acrylic Resins; D002368:Castor Oil / Q000494:pharmacology*; D003764:Dental Materials; D006920:Hygiene; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D012278:Ricinus; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D013499:Surface Properties / Q000187:drug effects; D014099:Toothbrushing
chemical_list: D000180:Acrylic Resins; D003764:Dental Materials; D002368:Castor Oil; D012973:Sodium Hypochlorite
keywords: Denture cleansers; acrylic resin; scanning electron microscopy; surface properties