Purpose: This study aimed to evaluate the influence of surface sealants on the surface roughness of composite resins. Materials and Methods: The study used microfilled composite resin (Metafil CX, Sun Medical Co.) and hybrid composite resin (Aelite™ LS posterior, Bisco). Sixty specimens (8 mm in diameter and 4 mm in height) of each composite resin type were prepared and divided into 3 groups. Each specimen was ground with 600, 1000, and 2000-grit sandpaper. The Surface roughness (Ra) values were measured using a surface roughness tester (SJ-301, Mytutoyo) before and after surface sealant application. Surface sealants, BisCover™ LV (Bisco), Optiguard® (Kerr), and Seal-n-Shine™ (Pulpdent), were applied to the specimens, as instructed and observed by scanning electron microscope (JSM-7500, JEOL) and atomic force microscope (MultiMode IV, Veeco Instruments). Results: Specimens ground with 600-grit sandpaper coated with surface sealants exhibited significantly lower Ra values than the untreated group (P < 0.05).Specimens ground with 1000 and 2000-grit sandpaper showed statistically no difference. There was no significant difference in surface roughness among BisCover™ LV, Optiguard®, and Seal-n-Shine™. SEM and AFM revealed remarkably decreased microdefects on the surfaces of composite resins after surface sealant application. Conclusion Surface sealants can influence surface roughness when applied on the rough surface of composite resins but not on highly polished composite resins.

Purpose: A mismatched size in the post and post space is a common problem during post-fixation. Since this discordance affects the bonding strength of the fiber-reinforced composite resin post (FRC Post), a corresponding luting agent is required. The aim of this study was to evaluate the bonding strength of the FRC post according to the fitness of the fiber post and the type of luting agent. Materials and Methods: Thirty mandibular premolar were endodontic-treated and assigned to two groups according to their prepared post space: Fitting (F) and Mismatching (M). These groups were further classified into three subgroups according to their luting agent: RelyX Unicem (ReX), Luxacore dual (Lux), and Duolink (Duo). A push-out test was performed to measure the push-out bond strengths. The fractured surfaces of each cross-section were then examined, and the fracture modes were classified. Results In the ReX and Duo subgroups, the F group had a higher mean bond strength; however, the Lux subgroup had no significant difference between the F and M groups. In the analysis of the failure modes, the ReX subgroup had only adhesive failures between the cement and dentin. Conclusion: The result of this study showed that the bond strength of an FRC post was influenced by the type of luting agent and the mismatch between the diameter of the prepared post space and that of the post.

Dens in dente is a developmental anomaly resulting from infolding of the enamel organ into dental papilla prior to calcification of dental tissue. The pulpal tissue of the tooth can be vulnerable for bacterial invasion through direct exposure to the oral cavity or through defective enamel and dentin of the infolding part, thereby increasing the possibility of pulpal necrosis and subsequent apical periodontitis. Treatment planning of teeth with dens invaginatus may be difficult due to the complex root canal morphology. Therefore, thorough knowledge of anatomical variations of dens invaginatus is of great importance for proper treatment planning. The focus of this case report is on Oehler’s type II and III dens invaginatus. The infolding of type III dens invaginatus extends beyond the crown and CEJ. Bacterial invasion through the infolding can easily cause inflammation of the pulpal and periradicular tissue. This case report presents endodontic treatment of type II and III dens invaginatus with the aid of CBCT.