The effect of flowable composite lining and dentin location on microtensile bond strength and internal fracture formation

Abstract

The objective of this study was to determine the effect of flowable composite lining and dentin location on internal dentin fracture formation in the microtensile bond strength (MTBS) test using swept-source optical coherence tomography (SS-OCT). MTBS test beams (1.0×1.0 mm) were prepared from human superficial and deep dentin, which was bonded with a self-etch adhesive (Clearfil SE Bond) and hybrid composite resin (Clearfil AP-X), with or without flowable lining (Clearfil Majesty ES-Flow). We tested 4 groups according to placement technique (with vs. without flowable liner) and dentin (superficial vs. deep) locations. Cross-sectional 2D images of the bonded interface were obtained before and after the MTBS test. Internal dentin fracture after MTBT was observed as a bright zone in SS-OCT. Flowable lining significantly reduced internal fracture formation in dentin (p<0.05). Dentin location significantly influenced MTBS (p<0.05), and this was reduced by flowable lining usage.

Evaluation of Micro-Tensile Bond Strength of A New Resin Composite Restorative Material at Two Different Dentin Depth After Aging (An In-Vitro Study)

“…Depth-associated variations in dentin components include tubule density, diameter and the mineral contents of the matrix influence mechanical properties, such as elastic modulus, which reduces the position moves from the DEJ to the pulp, the reduced mechanical properties of deep dentin induced a lower resistance to fracture, which resulted in lower bond strength and increased internal fracture formation when compared with superficial dentin. 16 These results corroborated those of Yang B et al (2006) 17 , who discovered that superficial dentin had a significantly higher μTBS than deep and cervical dentin due to the possibility of greater micromechanical adhesion to collagen fibrils in the hybrid layer because superficial dentin has a larger intertubular dentin area rich in collagen fibrils. Additionally in agreement with Pegado RE et al, 2010 18 , who discovered that for all adhesive systems tested, the bond strength obtained with superficial dentin was significantly higher than that of deep dentin due to the low contents of intertubular dentin and collagen fibrils as well as the high water content.…”

Toward esthetically and biomechanically reliable anterior resin composite restorations: Current clinical experiences among dental practitioners in Saudi Arabia

“…24,25 Dentists differ in their judgment regarding the necessity of using an intermediate liner beneath resin composites in anterior teeth. 26 Moreover, they differ in selecting a particular brand of resin composite material and a specific restoration technique for a particular clinical situation when restoring anterior tooth defects. This cross-sectional survey was therefore designed to investigate the current clinical practices of general dental practitioners in Saudi Arabia regarding the restoration of anterior tooth defects using resin composites.…”

Toward esthetically and biomechanically reliable anterior resin composite restorations: Current clinical experiences among dental practitioners in Saudi Arabia

“…24 , 25 Dentists differ in their judgment regarding the necessity of using an intermediate liner beneath resin composites in anterior teeth. 26 Moreover, they differ in selecting a particular brand of resin composite material and a specific restoration technique for a particular clinical situation when restoring anterior tooth defects.…”