Aging effect of different types of composite resin restoration on shear bond strength to different orthodontic adhesives with sapphire bracket (In vitro comparative study)


Background: This study was performed to determine the effect of aging of different types of composite materialrestorations on: Shear bond strength (SBS) to light cure and no mix chemical cure orthodontic adhesives withsapphire bracket and the debonding failure sites.Materials and methods: One hundred forty four composite disks were made from three different composite resinmaterials which are: 3M Filtek Z250, 3M filtek Z350 and 3M Valux plus, each group with (48) disks each, thenaccording to the duration of storage each group was subdivided into two equal groups one of them stored for oneday and the other was stored for one month, then each group was further subdivided into two equal subgroups with(12) disks each one bonded with light cure orthodontic adhesive and the other with no mix chemical cure adhesive.The sample was tested for bond strength using the universal testing machine and the Adhesive Remnant Index (ARI)was inspected under the stereomicroscope.Results: The results revealed that there was a highly significant difference among the three types of compositematerials bonded with light cure orthodontic adhesive as showed by ANOVA test, while the T test showed that therewas no significant difference between the two storage durations and also between the two orthodontic adhesivesfor both Filtek Z250 and Valux plus.Conclusions: The highest (SBS) values were obtained from Filtek Z350 samples than other two types of composite. Allthe samples stored for one day showed higher values of (SBS) than those stored for one month