Filtektm z250

Three commercial restorative materials, including nanohybrid resin composite (Filtek^TM Z250XT, 3M ESPE, St. Paul, MN, USA), microhybrid resin composite (Filtek^TM Z250, 3M ESPE, St. Paul, MN, USA), and dental amalgam (Tytin^TM, Kerr Corp., CA, USA) were tested in this study (Table 1).

A micro-hybrid composite resin [(Filtek^TM Z250; 3M ESPE, St. Paul, MN, USA)], a bulk-fill composite resin [(Filtek^TM Bulk Fill Posterior; 3M ESPE, St. Paul, MN, USA)], a giomer-based bulk-fill composite resin [(Beautifil^® Bulk Restorative; Shofu Inc., Kyoto, Japan), and a bioactive bulk-fill restorative material [(ACTIVA^TM BioACTIVE; Pulpdent Corporation, Watertown, MA, USA)] were used in the study. A light shade was selected for each material (shade A1, except for ACTIVA^TM BioACTIVE) for optimal light penetration. The curing light units used in this study were Woodpecker LED-E [Woodpecker Medical Instrument Co., Guilin, China] and CarboLED CL-01 [GCP Dental, Ridderkerk, Netherlands]. The power intensity of the light-curing units used was measured using a digital radiometer (Woodpecker LED Light Meter; Woodpecker Medical Instrument Co., Guilin, China). Details of the materials and the light-curing units are listed in Table 1 and Table 2, respectively.