In-vitro investigations on suitability of light-cured resins for interocclusal splints: part I: mechanical properties.
OBJECTIVE
It was the aim of the present study to investigate the material properties of different resins and their suitability for the fabrication of occlusal and intermaxillary splints.


METHODS
We subjected auto-polymerized resins (Palapress, Orthocryl, Steady-Resin M) and light-polymerized resins (Acrylight, Primosplint, Triad TranSheet Colorless and Pink) to investigation. The Targis Power light oven was used to polymerize the light-cured resins. After the auto-polymerized resins had been mixed by hand and filled into the forms, they were polymerized for 15 minutes in a high-pressure polymerization machine (Palamat) at 2 bar. The parameters examined were flexural strength, water adsorption, and polymerization shrinkage. Tests carried out according to DIN EN ISO 1567 served to determine flexural strength, flexural modulus, and water adsorption. Polymerization shrinkage was determined via the buoyancy test.


RESULTS
The resins' flexural strength ranged from 60 to 101 MPa. Flexural moduli lay between 1.3 and 5.3 GPa. The water adsorption noted in light-cured resins amounted to 2.1-4.6 mass percent. Palapress and Steady-Resin displayed the lowest water adsorption with 2.0 mass percent. The light-polymerized resins revealed significantly less shrinkage (p < 0.05) than the autopolymerized resins tested in this study.


CONCLUSIONS
Our results demonstrate that the light-cured resins-with the exception of Acrylight -easily match and even exceed the material properties of the cold-polymerized resins regarding flexural strength, flexural modulus, water adsorption and polymerization shrinkage. The light-cured resins examined thus seem suitable for use as splint material.
Danesh
Gholamreza
G
Department of Orthodontics and Dentofacial Orthopedics, University of Münster, Münster, Germany.
Lippold
Carsten
C
Ziebura
Thomas
T
Reinhardt
Klaus-Jürgen
KJ
Schäfer
Edgar
E
Ehmer
Ulrike
U
D000042:Absorption / Q000528:radiation effects; D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects*; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects*; D004548:Elasticity / Q000528:radiation effects; D006244:Hardness / Q000528:radiation effects; D008027:Light; D008422:Materials Testing; D019563:Mechanics; D017090:Occlusal Splints; D010777:Photochemistry / Q000295:instrumentation / Q000379:methods; D013718:Tensile Strength / Q000528:radiation effects; D014867:Water / Q000737:chemistry*
D000180:Acrylic Resins; D003764:Dental Materials; D014867:Water