Figure 2. Preparation of specimens for degree of conversion: A- Vinyl mold; B- Teflon mold; C- Teflon mold positioned around vinyl mold; D- Insertion of resin cement into vinyl mold; E- Ceramic disc positioned over the resin cement specimen; F- Teflon ring positioned around the ceramic disc; G- Light-curing of resin cement through ceramic disc using a QTH unit.