Influence of filling technique and curing mode on the bond strengths of composite cores to pulpal floor dentin

Abstract

This study evaluated the influence of filling technique and curing mode on the microtensile bond strengths (MTBS) of composite cores to pulpal floor dentin. Access cavities of human molars with pulpal floor dentin were restored with a two-step self-etch adhesive system, Clearfil Liner Bond 2V and a composite core, Clearfil DC Core Automix, using different filling techniques and curing strategies. A flowable resin composite, Clearfil Flow FX was placed on the cured adhesive resin prior to restoration with a composite core. Packing the composite in the access cavity was performed in bulk with or without light curing or using an incremental technique with light curing. Microtensile bond strengths to pulpal floor dentin were measured after 24 hours storage in water. Light curing and incremental technique had positive effects on the MTBSs. Lining with a flowable resin composite did not significantly improve the MTBSs, however, influenced the failure mode after debonding. Non-lining and bulk filling with chemical curing strategy provided the lowest MTBS.

Repair bond strength of dual-cured resin composite core buildup materials

“…For the building of extensively damaged teeth, some clinicians currently prefer the use of dual-cured resin composites [2] . This type of resin composite is utilized to overcome the limitations of both extended chairside time [3] , and depth of cure problems [4] that can occur with incremental layering techniques [5] . Dual-cured resin composite buildup restoratives combine the advantages of light- and self-cured mechanisms, in regard to a redox initiator system and photoinitiators [6] Polymerization is mainly initiated by light activation in the superficial layers of the materials and by chemical activation in the deeper layers even when the curing light is severely attenuated [7] .…”

Evaluation of Composite Adaptation to Pulpal Chamber Floor Using Optical Coherence Tomography

“…For successful adhesive restorations in endodontically treated teeth, it is important to obtain good dentin bonding to pulpal floor dentin as the latter always remains in any non-vital tooth that requires restoration. To date, several studies have examined the bond strength of composite restorations to pulpal floor dentin (23)(24)(25), but few studies have focused on interfacial gaps. The results obtained in the present study showed that highviscosity composites adapted more poorly to the pulp chamber floor than flowable composites, either traditional or bulk-fill.…”

The effects of total-etch, wet-bonding, and light-curing of adhesive on the apical seal of a resin-based root canal filling system

“…9 The degree of conversion (DC) at the interface between the self-curing resin core material and the acidic self-etch adhesive was low, because the acidity of the oxygen-inhibited layer on the adhesive hindered the chemical cure of the core material at the interface. 10,11 For adequate polymerization of the root canal sealer in the deepest apical part of the canal, dual curing of the sealer is required because of the limited penetration depth of the curing light through the opaque dentin and the Resilon filling material. However, the presence of a high percentage of hydrophilic acidic monomers and residual water in self-etching primers including the RealSeal primer can lead to sub-optimal DC, which results in poor mechanical properties and high permeability of the adhesive joint.…”