Comparative Study on The Structure, Physical Properties and Hardness Indentation of a Bulk Fill &amp; An Incremental Composite Resin Restorative Materials

Amira Elsherbeny,Sayed Mohamed Ghorab,Rizk Mostafa Shalaby

doi:10.24297/jap.v17i.8695

Abstract

Totally 80 disk-shaped specimens of Filtek™ Bulk-Fill, 3M ESPE, and Filtek™ Z250 XT, 3M ESPE, were prepared by using split-Teflon mold (4mm×10mm). Specimen characterization XRD, Surface roughness, degree of conversion, Surface microhardness, and depth of cure of the specimens were evaluated after the specimens were stored in distilled water in darkness at 37°C for 24 h. Statistical analysis was done using t-test with a significance level at p<0.05. FiltekTM Z350 XT showed the highest mean value of Vickers microhardness either on top surface 94.94% or bottom surface 69.92% and recorded 76.51% while FiltekTM Bulk-Fill was 66.85% for depth of cure. Filtek bulk-fill recorded a lower mean value of 0.73 for Surface roughness than FiltekTM Z350 XT and the highest degree of conversion of 84.34%. Statistical analysis showed that there was a significant difference between the mean values for all tested results. Increasing the filler content proved to have ability to enhance some properties, specially the surface roughness. Incorporation of some structurally rigid monomers like Bis-DMA, UDMA, TEGDMA within the resin matrix have a great influence on the measured properties, including degree of conversion reached to 84.34%, depth of cure to a level of 76.51% and Vickers microhardness to 94.94%.

Highlights

Resin-based composites were successfully introduced to dentistry for the last few years to replace amalgam as a posterior restoration and overcome the esthetic problem rather than the functional problem of dental amalgam [1]
The results show that the tested upper surface of the FiltekTM Z350 XT group has the highest mean value of Vickers microhardness (94.94±15.51), while the lowest value was for the lower surface of the FiltekTM Bulk-Fill group (57.79±4.03) as shown in table 3
Based on the results evaluated from this study, we noted that the FiltekTM Bulk-Fill resin composite exhibits a higher degree of conversion, lower depth of cure and a lower mean value of surface roughness than the incremental resin composite

Summary

Introduction

Resin-based composites were successfully introduced to dentistry for the last few years to replace amalgam as a posterior restoration and overcome the esthetic problem rather than the functional problem of dental amalgam [1]. There may be chances of moisture contamination, the possibility of voids inc orporation or air bubble entrapment, bond failures between each incremental layer of the resin composite [6]. It has a rough surface and a high tendency to discoloration. 4mmthickness as a bulk and cured in one step unlike the incremental fill technique [7, 8] Using this type of composite resin is easier and faster than the incremental type, decreased moisture contamination and air bubbles. The ai m of this study was to evaluate the structure, degree of conversion (DC %), Vickers microhardness (HV), depth of cure and surface roughness of bulk-fill resin-based composite and compare these measurements to those of incremental resin-based composite

Methods

Results

Conclusion