Properties of eight methacrylated beta-cyclodextrin composite formulations.
OBJECTIVE
Methacrylated beta-cyclodextrins (MCDs) are novel candidate dental monomers if all or some of the hydroxyl groups of beta-cyclodextrin are substituted with methacrylate groups. The main objective of this study was to evaluate mechanical properties of a number of composite formulations having MCDs as novel dental comonomers. The properties determined were flexural strength (FS), volumetric shrinkage (VS), and degree of conversion (DC).


METHODS
A mass fraction of 50% of MCD monomers was mixed with a mass fraction of 50% each of a series of dimethacrylate or monomethacrylate diluent comonomers to produce consistent formulations of a workable viscosity. For comparison a resin mixture of a mass fraction of 50% Bis-GMA and a mass fraction of 50% triethyleneglycol dimethacrylate (a typical dental resin mixture) was also studied. The mixtures were activated with camphorquinone and ethyl 4-dimethylamino benzoate. One part by mass of each activated resin formulation was mixed with three parts by mass of glass filler. Samples for the FS tests were prepared in (2 x 2 x 25) mm3 molds by light-curing the composites for 2 min on each side. The cured samples were immersed in 37 degrees C water for 24 h, and FS was measured with an Instron machine at a crosshead speed of 0.5 mm/min. VS was measured by a computer-controlled mercury dilatometer. DC was measured by near-infrared spectroscopy.


RESULTS
The properties of the MCD-based composites depended on the kind of diluent used. With these MCD monomers, diluents of triethyleneglycol dimethacrylate, 1,10-decamethylenediol dimethacrylate, or benzyl methacrylate yielded the best composite properties.


CONCLUSIONS
Although not yet fully optimized, MCD-based composite formulations containing triethyleneglycol dimethacrylate, 1,10-decamethylenediol dimethacrylate, or benzyl methacrylate yielded flexural strength and volumetric shrinkage values were comparable to those of the Bis-GMA/triethyleneglycol dimethacrylate controls. These findings lend support for further development and evaluations of polymerizable cyclodextrin derivatives for use in dental materials.
Hussain
Latiff A
LA
Paffenbarger Research Center, American Dental Association Foundation, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8546, Gaithersburg, MD 20899, USA. latiff.hussain@nist.gov
Dickens
Sabine H
SH
Bowen
Rafael L
RL
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D018772:Dental Marginal Adaptation; D003799:Dental Stress Analysis; D008422:Materials Testing; D008689:Methacrylates; D044367:Phase Transition; D018583:Pliability; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D047392:beta-Cyclodextrins / Q000737:chemistry* / Q000528:radiation effects
D003188:Composite Resins; D008689:Methacrylates; D011109:Polymethacrylic Acids; D047392:beta-Cyclodextrins; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate