Background: The aesthetic goals of our patients in dentistry have become a major concern in today’s world. Discoloured vital anterior teeth have long been treated with different approaches including crowns, direct and indirect veneers, composite resin, and most conservatively bleaching. The use of composite resins is increasing due to minimal tooth reduction and cost effectiveness as compared to ceramic veneers to achieve the optical properties of natural teeth. But very often in daily dental practice, tooth-coloured restorations already exist in the teeth that are planned to be bleached. Materials and Methodology: 40 disc shaped composite specimens (A2 shade) were fabricated measuring 10mm in diameter and 2mm in thickness using a stainless steel mould. The mould was placed on a mylar strip using a glass slab and overfilled with composite resin. Another mylar strip was placed on top of the mould and pressured with a glass slab to eliminate possible voids and remove excess material. The light-cured composite material used in the study was Gaenial GC A2 shade (GC Corporation, Japan). The composite resin was covered with acetate matrix strips and light cured. Specimens were light-cured for 9 seconds by a light-curing unit- (LCU) based on LED (Woodpecker, China). Following light-curing, the specimens were removed from the molds and placed at 37◦C distilled water for 24 hours to assure complete polymerization. Elastomeric putty impression of the samples (10 per group) were taken in an impression tray and casts were poured. Composite of 0.5 mm thickness was placed over the cast surface which acted as a separator. Four vacuum forming trays were fabricated using vacuum forming machine for each group. Results: The variables used in this study were one restorative material with three bleaching agents and artificial saliva as the control group. Statistical analysis done using Analysis of variance (ANOVA) with ‘p’ value <0.05 showed that the results between all the groups was statistically insignificant. Conclusion: Among the bleaching agents, 9% hydrogen peroxide (ΔE=0.615) had the highest colour change when compared to 10% carbamide peroxide (ΔE=0.482) and sodium perborate (ΔE=0.425). However the results were statistically insignificant with the control group. Gaenial GC, a microfilled hybrid composite has better colour stability when exposed to 9% hydrogen peroxide, 10% carbamide peroxide and sodium perborate which is in the clinically acceptable range.
Key words: Bleaching Agents, composite Colour, hydrogen peroxide, carbamide peroxide, sodium perborate.
Received: 11 April, 2019 Revised: 12 June 2019 Accepted: 15 June 2019
Corresponding author: Dr. Ganapati Anil Kumar, Senior Lecturer, Dept. of Conservative Dentistry & Endodontics, Sibar Institute of Dental Sciences, Guntur, AP, India
This article may be cited as: Kumar GA, Mahajan SB, Salim S, ur Rahman MM, Amir BA, Raheem F. An in Vitro Evaluation of effect of Bleaching Agents on Composite Colour. J Adv Med Dent Scie Res 2019;7(7): 25-30.