Effect of vital bleaching on surface roughness and microhardness of nanofilled and nanohybrid composite resins
Surface roughness and Microhardness data before and after bleaching. Ceram.x® SphereTEC™ one (Dentsply, Sirona) [Group 1] and Filtek Z350 XT (3M ESPE, St. Paul, USA) [Group 2]
Steps to reproduce
A customized split mold was used to fabricate twenty disc shaped specimen of 10 mm diameter and 2 mm height of Ceram.x® SphereTEC™ one (Dentsply, Sirona) [Group 1] and Filtek Z350 XT (3M ESPE, St. Paul, USA) [Group 2]. After the composite material is packed into the mold, mylar strip was used both on top and bottom surfaces to obtain a smooth surface on the composite. Subsequently, the composite material was cured for 20 seconds on both sides using a visible light curing unit (3M ESPE Elipar, St Paul, USA). The prepared discs were subjected to in-office bleaching using 35% hydrogen peroxide (Pola office, SDI Limited, Australia) as per the manufacturer’s instructions. The procedure involved applying a bleaching agent two times with a one-week interval between the applications. The bleaching protocol involved the application of a bleaching agent three times onto the surfaces of each disc for 15mins. The discs were rinsed with distilled water for one minute between each application. After the bleaching process, all the discs were stored in distilled water. The surface hardness of the discs before and after the bleaching was measured using Vickers hardness testing machine [Matsuzawa Company, Japan] and was reported as VHN. Surface roughness before and after bleaching was measured using a surface profilometer (Surtronics 3+, Taylor Hobson, UK) in microns.