The effect of cyclic immersion in cola drinks on the surface microhardness and surface roughness of different composite filling resin materials

Abstract EN

Background : The aim of this study was to evaluate the effect of two types of cola drinks (Regular and Diet) on the surface microhardness and surface roughness of three types of composite resins; Filtek P60 (Packable composite), Tetric-N-Ceram (Nanohybrid composite) and Swisstec (Conventional composite, and to measure the neutralisable acidity of cola drinks.

Materials and methods : Total number of 180 samples are prepared, 60 samples for each type of composite, were divided into two main groups 30 subjected for microhardness test (by Vickers hardness tester) and 30 subjected to surface roughness test (by profilometer).

in which composite samples were alternately immersed manually, 5 seconds each, in cola drink and artificial saliva for 10 cycles at room temperature which repeated three times a day (8am,4pm,12am) at 8hours intervals for one week.

Results : Surface microhardness results showed that both types of cola drinks affect the Filtek P60 (packable) composite resin significantly while their effect was with high significant difference for Swisstec (conventional) composite and Tetric-n-Ceram (nanohybrid) composite resin, so the influence of cola drinks was material dependent.

Surface roughness results showed that Filtek P60 (packable) composite resin non significantly affected by regular Pepsi and significantly in diet Pepsi, while Tetric-n-Ceram (nanohybrid) composite and Swisstec (conventional) composite showed a high significant difference in both cola drinks, so the influence of cola drinks was material dependent.

All types of composites tested in this study showed reduction in VHN values and increasing in means of Ra values after 7 days of immersion in artificial saliva, but the effect was a non significant.

Conclusions : Both cola drinks showed reduction in means VHN values and increasing in means Ra values for all types of composites for all groups.

Regular Pepsi is less in their erosive potential and need lesser amount of NaOH to reach the neutrality than diet Pepsi.