Nanofilled and microhybrid composite restorations: Five-year clinical wear performances

ObjectivesTo compare the clinical wear performance of nanofilled restorations (Filtek Supreme) against microhybrid restorations (Z100) in a 5-year randomized clinical trial to evaluate the wear rate and the influence of subject-, operator- and restoration-related variables on wear rate.Materials and methods18 Filtek Supreme and 17 Z100 restorations were placed in human molars (split-mouth-model) and bonded with Single Bond/Scotch Bond Adhesive. Restorations were recalled at baseline, 6-, 12-months and at annual intervals until 5-years of clinical service. The gypsum replicas at each recall were used for 3D-Pro-laser scanning to quantify wear and the epoxy resin replicas were observed under SEM for microwear patterns. Linear-mixed-models were used to study the influence of the different variables on the vertical and volume loss.ResultsZ100Filtek SupremeVertical wear (μm/month)Generalised0.8700. 9250–6 m/running-in wear5.5636.9876–36 m/early stage0.9741.28836–60 m/steady state0.4860.263Volume loss (mm3/month)Generalised0.0140.0110–6 m/running-in wear0.0170.0116–36 m/early stage0.0060.00536–60 m/steady state0.0310.023Full-size tableTable optionsView in workspaceDownload as CSVVolume wear, but not the vertical wear rate of the two restorative materials were significantly influenced (p < 0.05) by the factors such as operator, cavity type, as well as combination of operator–cavity type and quadrant type. The variations in the occlusal surface microwear patterns over time reflect the effect of biomechanics of mastication on the restorative composite.ConclusionsThe rate of vertical and volume loss of both the restoratives appear, on average, not to be constant even after the early stage wear, under the influence of certain clinical variables.