Influence of adhesive-composite application modalities on their bonding to tooth structure and resistance of the performed restorations to failure

Abstract

Background/purpose The longevity of bonded composite restorations could be affected by the utilized adhesive-composite application techniques. This in vitro study aimed to evaluate the influence of adhesive-composite application modalities on their bonding values to tooth structure and on the failure resistance of the performed restorations on loading. Materials and methods Resin composite studs, 2 mm in diameter and 4 mm high, were bonded in 2 groups to flattened enamel and dentin surfaces of 80 extracted premolars using pre-cured (PC) and co-cured (CC) self-etch resin adhesive. Studs in each group were built-up in 4 subgroups using either multiple increments of nano-filled composite (IF, control) or single increment of preheated nano-filled (PH), bulk-fill (BF) and sonic-activated bulk-fill composites (SF). Another 80 premolars with standard class II cavities were also restored using the same adhesive-composite application modalities. All specimens were then stressed on a universal testing machine to assess the composite-tooth shear bond strength and the resistance of the performed restorations to failure. The modes of specimens’ failure were also assessed following each test. Results The PC adhesive provided higher bond strength to dentin (p < 0.05) and comparable bond strength to enamel in comparison to the CC one (p>0.05%). Both PH and BF composites showed lower bond strength to dentin in presence of PC adhesive (p < 0.05). Comparable bond strengths were noticed for PH, BF and SF composites to dentin in presence of CC adhesive (p > 0.05). PH and SF restorations presented the highest resistance to failure (p < 0.05). Conclusion Both incrementally and bulky-inserted composites offer clinically acceptable bond strength in presence of pre-cured resin adhesive. Both Preheated and sonic-activated composite restorations offer the highest resistance to failure on loading. The preheating procedure renders regular composite material suitable for bulk-fill applications.

An evaluation of surface roughness after staining of different composite resins using atomic force microscopy and a profilometer

“…Composite resins have become usable, not only in the anterior, but also in the posterior region due to changes in resin matrix content, and improvements in composite particle structure and size, and surface properties. (Abdelaziz & Saleh, 2018; Korkmaz, Ozel, Attar, & Aksoy, 2008) One of the most important properties of composite resins, which achieve significant cosmetic success, is surface roughness. The surface smoothness of composite resins is associated with plaque accumulation, the health of the periodontal tissues, discoloration and optical properties, water absorption, and surface damage in the restoration (Janus, Fauxpoint, Arntz, Pelletier, & Etienne, 2010).…”

Comparative Assessment of Different Pre-Treatment Bonding Strategies to Improve the Adhesion of Self-Adhesive Composites to Dentin

“…To further simplify the restorative procedure, the co-curing technique was introduced. In this technique, the polymerization of the primer/adhesive and the self-adhesive composite occurs simultaneously [ 23 , 37 , 38 ]. Notably, these groups exhibited three-fold higher bond strength values than the groups where etching was carried out as a stand-alone treatment.…”

Comparing the bond strength of fiber post cementation in the root canal using pre- and co-curing procedures with the same self-etching bonding system

“…The coronally larger cement space in group SE-pre compared with that in group SE-co also corresponds with previous findings. 5 , 6 , 7 Therefore, the pre-curing method might be an appropriate choice if the post space is more extensive.…”

“…Abdelaziz et al. 7 demonstrated that in direct composite resin restorations, the pre-curing method provided better dentin bond strength than the co-curing method. However, using the pre-curing method for cementing fiber posts may affect the fit of the post in the canal space owing to the thickness of the polymerized bond layer, and an ill-fitting post will degrade the bond strength.…”