Conventional and high intensity halogen light effects on water sorption and microhardness of orthodontic adhesives.
OBJECTIVE
To test the null hypothesis that when the equivalent total light energy is irradiated to three orthodontic adhesive resins, there is no difference between the microhardness and water sorption values regardless of the curing light sources.


METHODS
Samples were divided into six groups according to the combination of three orthodontic adhesives (Kurasper F, Light-Bond, Transbond XT) and two light intensities (quartz tungsten halogen [QTH] and high intensity quartz tungsten halogen [HQTH]). One half of each of the 40 samples of three adhesive pastes was polymerized for 20 seconds by a QTH light source, and the other half was polymerized for 10 seconds by a HQTH light source. Water sorption was determined and Vickers hardness was established with three measurements per sample at the top, center, and bottom. Statistical analysis was performed using two-way analysis of variance (ANOVA) with multiple comparisons (Tukey-HSD).


RESULTS
Statistically significant differences were found among all adhesives for water sorption and hardness values cured with QTH and HQTH. The HQTH curing unit resulted in higher values than did the QTH. The highest water sorption values were observed for Kurasper F cured with HQTH and the lowest value was observed for Transbond XT cured with QTH. For microhardness Light-Bond cured with HQTH produced the highest values, and Transbond XT cured with QTH produced the lowest.


CONCLUSIONS
When the equivalent total light energy is irradiated to three orthodontic adhesive resins, there are significant differences between the microhardness and water sorption values cured with the QTH and HQTH light source. The null hypothesis is rejected.
Uysal
Tancan
T
Department of Orthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey. tancanuysal@yahoo.com
Basciftci
Faruk Ayhan
FA
Sener
Yagmur
Y
Botsali
Murat Selim
MS
Demir
Abdullah
A
D000042:Absorption; D000180:Acrylic Resins / Q000737:chemistry; D000327:Adsorption; D003188:Composite Resins / Q000737:chemistry; D004867:Equipment Design; D006244:Hardness; D006801:Humans; D008029:Lighting / Q000295:instrumentation*; D008422:Materials Testing; D009967:Orthodontic Appliances; D010756:Phosphoric Acids / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry* / Q000528:radiation effects; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
D000180:Acrylic Resins; D003188:Composite Resins; C472990:Kurasper F; D010756:Phosphoric Acids; D011108:Polymers; C429652:Reliance Light Bond; D019279:Resin Cements; C477790:Transbond XT; D014867:Water