A Push-out Bond Strength Study and Interface Analysis of New Porous Titanium Dental Post Luted with Resin Cement This study aimed to compare the push-out bond strength (PBS) between a new porous titanium post (PTP) and other marketed dental posts cemented with two types of dual-cure resin cement. A total of 96 extracted single-rooted human teeth were recruited. Four types of dental posts (n = 24 each), namely: stainless steel post (SSP), commercially-pure titanium post (CTP), fibre glass post (FGP), and PTP were cemented with two types of resin cements (RelyX U200 and ParaCore) and then sectioned at coronal and middle root levels. The specimens were subjected to a PBS test at a crosshead speed of 0.5 mm/min. The interface analysis was performed using a stereomicroscope and scanning electron microscope. A p-value < 0.05 was considered significant for all statistical tests. PBS recordings showed that the highest PBS mean value in RelyX group was 2.68±1.10 MPa for PTP. The differences in PBS between PTP and SSP and FGP were not significant (p = 0.098 and p = 0.075, respectively). The null hypothesis for RelyX group at both coronal and middle sections of the root was retained (p > 0.05). No failure at the post-cement interface was found in the PTP group, which was founder superior over the other posts (no gap for this interface was observed). The PTP showed similar bonding strength and adhesion to the other tested posts when using RelyX U200 cement. The PTP can be considered a new alternative option for the dental post system.

Resin-based pit fissure sealants (RBS) are used to prevent occlusal caries in children. The success of RBS in preventing dental caries is largely influenced by its retention on the tooth surface, which is also affected by its physicomechanical properties. The physicomechanical properties of RBS can be enhanced through the addition of fillers. With the advent of nanofillers, the physicomechanical properties were improved without altering RBS flowability. The present study developed an RBS with a 70 wt% resin matrix and 30 wt% nanofillers. The resin matrix consisted of urethane dimethacrylate (55 wt%), triethylene glycol dimethacrylate (45 wt%), camphoroquinone (0.3 wt%), and 2-(dimethylamino) ethyl methacrylate (0.7 wt%). Silane-treated rice husk-derived nanosilica (20 wt%) and nanohydroxyapatite (10 wt%) were added as fillers. Clinpro, Fissurit FX, and an unfilled sealant were controls. All RBS were tested for surface roughness, Vickers hardness, flexural strength, and flowability. Statistical analysis with oneway ANOVA revealed significant differences between groups in surface roughness, hardness, flowability (p < 0.001), flexural strength, and flexural modulus (p < 0.05). Experimental sealants had higher flexural strength (78 MPa) and flow distance (29.05+1.16 mm) than commercial controls.However, the surface roughness of experimental sealants (0.25+0.08 μm) was higher than Clinpro (0.087+0.027 μm) but lesser than Fissurit FX (0.35+0.19 μm). The Vickers hardness of experimental sealants (23+1.63 VHN) was less than Fissurit FX (28.80+1.69 VHN) but higher than Clinpro (21.74+1.68 VHN). This novel RBS had physicomechanical properties comparable to commercial sealants. The use of nanosilica from rice husk makes this pit and fissure sealer sustainable and environmentally friendly in dentistry.