title: Influence of dimethyl sulfoxide used as a solvent on the physical properties and long-term dentin bonding of hydrophilic resins.
abstract: To examine the feasibility of dimethyl sulfoxide (DMSO) incorporation into relatively hydrophilic resins as a new potential method to improve the durability of resin-dentin bonds.
  
  
  
  Six experimental light-curing BisGMA/HEMA resins solvated in ethanol and DMSO with increasing concentrations of DMSO (0, 0.5, 1, 2, 4 and 10wt%) were prepared. The degree of conversion (DC) was evaluated by Fourier Transform Infrared Spectroscopy (n=8); water sorption (Wsp) and water solubility (Wso) were gravimetrically assessed (n=10); and flexural strength (FS) and elastic modulus (E) were determined by a three-point bending flexural test (n=10). Flat dentin surfaces on sound third molars (n=10/group) were bonded with resins containing 0, 2, 4 and 10wt% DMSO used as a two-step etch-and-rinse system. Dentin microtensile bond strength was determined at 24h and after two-year aging in artificial saliva at 37°C.
  
  
  
  DMSO significantly affected Wsp (p=0.0006), DC, Wso, FS, and E (p<0.0001). In general, the resins' mechanical/physical properties were not affected by 2% or lower DMSO incorporation. Incorporation of 4% or higher DMSO content significantly increased DC, Wsp and Wso, but 2% or higher DMSO concentrations significantly reduced FS and E. No influence on immediate dentin bond strength occurred up to 4% DMSO incorporation. While 4% or higher DMSO concentrations impaired bond strength over time, the resin containing 2% DMSO presented significant higher dentin bond strength compared to the control resin after two year-aging.
  
  
  
  The use of DMSO as a new solvent in adhesive dentistry improves dentin bonding of relatively hydrophilic resins over time. 2% DMSO incorporation in BisGMA/HEMA resins should be sufficient to reduce bond strength loss without compromising polymer mechanical strength and physical properties.
authors: Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Lemminkaisenkatu 2, 20520 Turku, Finland; Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Av. Limeira Piracicaba, SP 13414-903, Brazil; Dental School of Presidente Prudente, University of Western São Paulo, Rua José Bongiovani, 700 - Cidade, Presidente Prudente, 19050-920 SP, Brazil. Electronic address: thiagohs@hotmail.com.
authors: Thiago Henrique Scarabello
authors: TH
authors: Stape
authors: Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Lemminkaisenkatu 2, 20520 Turku, Finland; Department of Restorative Dentistry and Cariology, Department of Prosthetic Dentistry, Institute of Dentistry, University of Turku, Turku, Finland. Electronic address: arztez@utu.fi.
authors: Arzu
authors: A
authors: Tezvergil-Mutluay
authors: Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Lemminkaisenkatu 2, 20520 Turku, Finland; Department of Cariology, Institute of Dentistry, University of Turku, Turku, Finland. Electronic address: mmutluay@gmail.com.
authors: Mustafa Murat
authors: MM
authors: Mutluay
authors: Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Av. Limeira Piracicaba, SP 13414-903, Brazil. Electronic address: martins@fop.unicamp.br.
authors: Luís Roberto Marcondes
authors: LR
authors: Martins
authors: Dental School of Presidente Prudente, University of Western São Paulo, Rua José Bongiovani, 700 - Cidade, Presidente Prudente, 19050-920 SP, Brazil. Electronic address: rosanahb@yahoo.com.br.
authors: Rosana Leal
authors: RL
authors: do Prado
authors: Dental School of Presidente Prudente, University of Western São Paulo, Rua José Bongiovani, 700 - Cidade, Presidente Prudente, 19050-920 SP, Brazil. Electronic address: elianepizi@unoeste.br.
authors: Eliane Cristina Gava
authors: EC
authors: Pizi
authors: Department of Oral and Maxillofacial Diseases, University of Helsinki, Helsinki, Finland; Helsinki University Hospital, Helsinki, Finland; Research Unit of Oral Health Sciences, and Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland. Electronic address: leo.tjaderhane@helsinki.fi.
authors: Leo
authors: L
authors: Tjäderhane
mesh_terms: D003188:Composite Resins; D055117:Curing Lights, Dental; D001840:Dental Bonding; D003804:Dentin / Q000737:chemistry*; D017220:Dentin-Bonding Agents; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D012997:Solvents; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; D012997:Solvents; D004121:Dimethyl Sulfoxide
keywords: Adhesion; Biomechanical properties; Dentin; Durability; Hybrid layer; Hydrophilicity