Initial reduction of the resin core by half the diameter of a 008 bur on the buccal and proximal surfaces was performed to create space for the thickness of opaque ceramic (ranging from 0.3 to 0.5 mm), which was required to conceal metallic color. Furthermore, subsequent casting and evaluation of adaptation to the dentin were carried out. Consequent stages encompassed all-ceramic restoration preparation, culminating in applying A3 ceramic opaque (Super Porcelain EX-3, Kuraray Noritake Dental Inc., Japan) to cover the core. Sintering was conducted using a furnace (VITA VACUMAT 6000 MP, Germany) [14 (link)] (Figure 1 ).
To ensure consistent cement thickness, light-body silicone was used to check post adaptation. The thickness of the silicone layer was examined under a microscope at two points: the cervical and apical areas and any dentin washes with a thickness other than 0.5 mm were removed and replaced. After confirming coordination between all posts and root canal dentin, self-cured glass ionomer cement (Luting & Lining Cement, GC, Tokyo, Japan) was utilized for cementation. Following a 24-hr interval, preparations for zirconia crowns were made [15 (link)].
To ensure consistent cement thickness, light-body silicone was used to check post adaptation. The thickness of the silicone layer was examined under a microscope at two points: the cervical and apical areas and any dentin washes with a thickness other than 0.5 mm were removed and replaced. After confirming coordination between all posts and root canal dentin, self-cured glass ionomer cement (Luting & Lining Cement, GC, Tokyo, Japan) was utilized for cementation. Following a 24-hr interval, preparations for zirconia crowns were made [15 (link)].