title: A castor oil-containing dental luting agent: effects of cyclic loading and storage time on flexural strength.
abstract: Favorable results in the use of castor oil polyurethane (COP) as pulp capping, membrane material, sealer, mouthwash and in bone repair, associated with the fact that Ricinus communis is not derived from petroleum and it is abundant in Brazil, encourage researches in the development of luting agents. Objectives This study compared the flexural strength (FS) of a castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate (COP10) with RelyX ARC (RX) after mechanical cycling (MC) and distilled water storage. Material and Methods Sixty-four specimens (25x2x2 mm) were fabricated and divided into two groups, COP10 and RX (control). Each group was divided into 4 subgroups (n=8) according to the storage time, 24 hours (24 h) or 60 days (60 d), and the performance (MC+FS) or not (only FS) of the mechanical cycling test. The FS (10 kN; 0.5 mm/min) and MC tests (10,000 cycles, 5 Hz, 0.5 mm/min) were carried out using an MTS-810 machine. The data were analyzed using ANOVA (α=0.05). Results The obtained FS (MPa) values were: COP10 24h- 19.04±2.41; COP10 60d- 17.92±3.54; RX 24h- 75.19±3.43; RX 60d- 88.77±6.89. All the RX specimens submitted to MC fractured, while the values for COP10 after MC were as follows: COP10 24h- 17.90±1.87 and COP10 60d- 18.60±1.60. Conclusions A castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate is resistant to mechanical cycling without decreases in flexural strength. However, mean COP10 showed only about 25% of the RelyX ARC mean flexural strength.
authors.affiliation: Department of Restorative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Juliana Dos Reis
authors.initials: Jdos R
authors.lastname: Derceli
authors.affiliation: Department of Dental Materials and Prosthodontics, Araraquara Dental School, Universidade Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Laiza Maria Grassi
authors.initials: LM
authors.lastname: Fais
authors.affiliation: Department of Dental Materials and Prosthodontics, Araraquara Dental School, Universidade Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Lígia Antunes Pereira
authors.initials: LA
authors.lastname: Pinelli
mesh_terms: D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D002368:Castor Oil / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D003799:Dental Stress Analysis; D007101:Immersion; D008422:Materials Testing; D018583:Pliability; D011092:Polyethylene Glycols / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry*; D012016:Reference Values; D013314:Stress, Mechanical; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003738:Dental Cements; D011109:Polymethacrylic Acids; D011140:Polyurethanes; C462240:RelyX ARC; D014867:Water; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D002368:Castor Oil; D002119:Calcium Carbonate