Graphene oxide nano-filler based experimental dentine adhesive. A SEM / EDX, Micro-Raman and microtensile bond strength analysis

Abstract

Aim: The study aimed to assess graphene oxide (GO) adhesive and its dentin interaction using scanning electron microscopy (SEM), MicroRaman spectroscopy and Microtensile bond strength (μTBS). Materials and Methods: Experimental GOA and control adhesives (CA) were fabricated. Presence of GO within the experimental adhesive resin was assessed using SEM and Micro-Raman spectroscopy. Ninety specimens were prepared, sixty teeth were utilized for μTBS, twenty for SEM analysis of interface for CA and GOA and ten were assessed using microRaman spectroscopy. Each specimen was sectioned and exposed dentine was conditioned (35% phosphoric acid) for 10 s. The surface was coated twice with adhesive (15 s) and photopolymerized (20 s). Composite build-up on specimen was photo-polymerized. Among the bonded specimens, thirty specimen were assessed using Micro-Raman spectrometer, SEM and energy dispersive X-ray spectroscopy (EDX), whereas remaining specimens were divided in to three sub-groups ( n = 10) based on the storage of 24 h, 8 weeks and 16 weeks. μTBS testing was performed at a crosshead speed of 0.5 mm/min using a microtensile tester. The means of μ-tbs were analyzed using ANOVA and post hoc Tukey multiple comparisons test. Results: No significant difference in μTBS of CA and GOA was observed. Storage time presented a significant interaction on the μTBS ( p < 0.01). The highest and lowest μTBS was evident in CA (30.47 (3.55)) at 24 h and CA (22.88 (3.61)) at 18 weeks. Micro-Raman analysis identified peaks of 1200 cm-1 to 1800 cm1, D and G bands of GO nanoparticles in the resin. Uniform distribution of graphene oxide nanoparticles was present at the adhesive and hybrid layer. Conclusion: GO showed interaction within adhesive and tooth dentin similar to CA, along with formation of hybrid layer. In ideal conditions (absence of nanoleakage), graphene oxide modified adhesive shows comparable bond strength and durability of resin dentine bond.

Synergistic effect of graphene oxide/calcium phosphate nanofiller in a dentin adhesive on its dentin bond integrity and degree of conversion. A scanning electron microscopy, energy dispersive X‐ray spectroscopy, Fourier transform infrared, micro‐Raman, and bond strength study

“…Another important issue is the loss of minerals from the resin‐dentin interface that leads to the biodegradation of the bond, ultimately leading to restorative failure (Wang, Spencer, & Yao, 2006). To improve the performance of adhesives, the addition of inorganic fillers inside adhesive's composition has been encouraged (Belli et al, 2014) as these fillers can decrease solubility of the adhesive (Itoh et al, 2010) and can also augment mechanical properties of the adhesive (Alshahrani et al, 2020). Furthermore, the addition of biomaterial‐based inorganic fillers can remineralize resin‐dentin bond, increasing longevity of the material (Niu et al, 2014).…”

Adhesive bond integrity of Y‐TZP post with calcium fluoride infiltrated resin dentin adhesive: An SEM, EDX, FTIR and micro‐Raman study

“…3 One of the approaches is to incorporate bioactive inorganic fillers in the adhesive. 4 The literature shows evidence of successfully incorporating these fillers in the adhesive with desired outcomes. 5 Previously, hydroxyapatite (HA), 6 silica, 7 and graphene oxide (GO) 8 fillers have been shown to reinforce the mechanical properties of dentin adhesives.…”

Dentin Bond Integrity of Hydroxyapatite Containing Resin Adhesive Enhanced with Graphene Oxide Nano-Particles—An SEM, EDX, Micro-Raman, and Microtensile Bond Strength Study

“…To overcome failure of adhesion over time, addition of inorganic fillers in adhesives is promoted to improve dentin interaction of adhesive resins and possibly minimize dentin-adhesive degradation [ 7 ]. Previous studies have shown that addition of fillers in adhesives can reduce water sorption and solubility [ 8 ], in addition to enhancing its mechanical properties [ 9 ]. Therefore, addition of inorganic nano-materials as fillers to develop the physical and mechanical properties of dentin adhesive’s is highly desirable.…”