Color Stability of New Composite Restorative Materials Under Accelerated Aging

Abstract

The color stability of seven commercial composite restorative materials under conditions of accelerated aging was evaluated by reflection spectrophotometry at baseline and 300, 600, and 900 h. During early aging the composites generally became darker, more chromatic, and more opaque. Changes in color of the conventional composites during aging were influenced by erosion of the resin matrices and exposure of filler particles. Color stability of the microfilled composites under the in vitro conditions tested was better than that of the conventional composites and did not appear to be influenced as much by erosion.

Color and opacity variations in three different resin-based composite products after water aging

“…Such change has been previously reported in the literature 3,4,5,6,15,16 . The problem in the evaluation of the results from this type of test is the limit in the ability to detect differences.…”

The color stability of aesthetic restorative materials resulting from accelerated aging

“…11,12 It was reported that if the kinetic of dimethacrylate monomer is limited, polymerization cannot increase any more, but if temperature rises, the kinetic of dimethacrylate monomer increases and the flexibility of polymer chain in the network is enhanced, and as a result, the degree of polymerization increases by post cure. 13 Power et al 14,15 reported that after accelerated aging under xenon light and 90 percent relative humidity, the matrices of resin eroded away and the filler was exposed, and as a result, the resin showed chalky surface and the roughness of the surface increased. 16 The absorption of water by composite resin is affected by the hydrophobic of the resin matrix.…”

“…And our results of the visual examination and SEM observation of changes caused by accelerated aging were consistent with the reports of Power et al above. 14,15 Occurrence of numerous microcracks and defects on the surface of SYNERGY Duo and TESCERA ATL after accelerated aging is probably because of the erosion of the resin matrix, hydrolysis of the fillers and polymerization shrinkage related to additional polymerization involving xenon light, heat, etc. Microcracks were much wider and longer in SYNERGY Duo than in TESCERA ATL, and the surface of SYNERGY Duo had many changes including the exposure of fillers over the substrate.…”

“…As to changes resulting from accelerated aging, Powers et al 15,16 reported that color change in conventional composite resin was affected more by the surface deterioration which has been shown to increase lightness and decrease chroma of restorative resins, and in fine-particle-type composite resin showing a small color change, the color change was caused by the continuous formation of colored degradation product rather than by the erosion of surface. And Douglass 1 reported that, different from that in hybrid composite resin, color change in ceramic-polymer was mostly a chromatic change with little change in value.…”

Surface roughness and color stability of various composite resins

“…Extrinsic factors for discoloration include staining by adsorption or absorption of colorants as a result of contamination from exogenous sources such as coffee, tea, and beverages [21][22][23] . Extrinsic factors include mechanical wear, microleakage, incomplete adhesion of composite resins and teeth, and rough surface [24][25][26][27] . Barkmeier and Cooley 28) were reported that the rougher of composite resin surface, the higher chance of staining and discoloration.…”