title: Properties of a proline-containing glass ionomer dental cement.
abstract: BACKGROUND
  Proline-containing glass ionomers are promising fast-set dental restorative materials with superior mechanical properties; however, little information is available on other physical properties of this type of glass ionomer.
  
  
  OBJECTIVE
  The objectives of this study were to synthesize and characterize a polyacrylic acid terpolymer containing proline derivative (PD) and to investigate the physical properties of this glass ionomer cement (GIC) and its cytotoxicity in vitro.
  
  
  METHODS
  A terpolymer of AA (acrylic acid), IA (itaconic acid), and proline derivative (MP) with an 8:1:1 molar ratio was synthesized and characterized. Experimental GIC specimens were made from the synthetized terpolymer with Fuji IX (GC America, Alsip, Ill) commercial glass ionomer powder as recommended by the manufacturer. Specimens were mixed and fabricated at room temperature and were conditioned in distilled water at 37°C for 1 day and 1 week. Vickers hardness was determined with a microhardness tester. The water sorption characteristics and fluoride releasing properties of the specimens were investigated. The in vitro cytotoxicity of the experimental glass ionomer was assessed by evaluating the C2C12 cell metabolism with methyltetrazolium (MTT) assay. Commercial Fuji IX was used as a control for comparison. The data obtained for the experimental GIC (PD) were compared with the control group by using 1- and 2-way ANOVA and the Tukey multiple range test at α=.05.
  
  
  RESULTS
  Proline-modified GIC (PD) exhibited significantly higher surface hardness values (Vickers hardness number [VHN] 58 ±6.1) in comparison to Fuji IX GIC (VHN 47 ±5.3) after 1 week of maturation. Statistical analysis of data showed that the water sorption properties of the experimental cement (PD) were significantly greater than those of the control group (P<.05). The experimental GIC showed a significant increase in the amounts of initial fluoride release (P<.05) with continued fluoride release from the bulk of the material. The experimental group showed slightly reduced cell metabolism and cell number in comparison to the control group. However, the results were not statistically different (P>.05).
  
  
  CONCLUSIONS
  An amino acid-containing GIC had better surface hardness properties than commercial Fuji IX GIC. This formulation of fast-set glass ionomer showed increased water sorption without adversely affecting the amount of fluoride release. Considering its biocompatibility, this material shows promise not only as a dental restorative material but also as a bone cement with low cytotoxicity.
authors.affiliation: Graduate student, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, Calif.
authors.forename: Sahar
authors.initials: S
authors.lastname: Ansari
authors.forename: Maryam
authors.initials: M
authors.lastname: Moshaverinia
authors.forename: Nima
authors.initials: N
authors.lastname: Roohpour
authors.forename: Winston W L
authors.initials: WW
authors.lastname: Chee
authors.forename: Scott R
authors.initials: SR
authors.lastname: Schricker
authors.forename: Alireza
authors.initials: A
authors.lastname: Moshaverinia
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000327:Adsorption; D000818:Animals; D002327:Cariostatic Agents / Q000737:chemistry; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D055598:Chemical Phenomena; D004396:Coloring Agents; D004058:Diffusion; D005459:Fluorides / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry* / Q000633:toxicity; D006244:Hardness; D008422:Materials Testing; D051379:Mice; D008970:Molecular Weight; D032342:Muscle Cells / Q000187:drug effects; D011392:Proline / Q000737:chemistry* / Q000633:toxicity; D013386:Succinates / Q000737:chemistry; D013696:Temperature; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D002327:Cariostatic Agents; D004396:Coloring Agents; D005899:Glass Ionomer Cements; D013386:Succinates; D013778:Tetrazolium Salts; D013844:Thiazoles; C110713:fuji IX; D014867:Water; C006903:carbopol 940; D011392:Proline; C022616:thiazolyl blue; C005229:itaconic acid; D005459:Fluorides