Resin-dentin interface with 150 days of aging by SEM. (a) Arrows show voids in the deepest portion of hybrid layer. (b) Degradation of collagen fibrils is evidenced (arrows) in the adhesive interface. (c) Loss of collagen in the intertubular dentin around the resin tags (arrows). (d) Degradation of the bonding interface with formation of water channels (arrows) and hydrolytic degradation of the resin adhesive. Bonded interfaces were created with Adper Single Bond 2 (3M ESPE, St. Paul, MN, USA). (SEM) scanning electron microscopy, (ITD) intertubular dentin, (T) dentin tubule, (DC) degraded collagen, (RT) resin tags, (HL) hybrid layer, (AL) adhesive layer. Bar corresponding to 10µm. Courtesy of Betancourt DE and Baldion PA with permission.