Adhesives Doped with Bioactive Niobophosphate Micro-Filler: Degree of Conversion and Microtensile Bond Strength

Abstract

To evaluate the effect of incorporating niobium phosphate bioactive glass (NbG) into commercial etch-and-rinse adhesive systems, with and without silane, on their degree of conversion (DC) (%) and microtensile bond strength (μTBS). The NbG micro-filler was added to two etch-and-rinse adhesive systems: One Step (OS) and Prime & Bond (PB) at 40% concentration. The following groups were formed: control without glass addition OS; addition of unsilanized NbG (OSNbG); addition of silanized NbG (OSNbGS); control without glass PB; addition of unsilanized NbG (PBNbG); addition of silanized NbG (PBNbGS). The DC was determined using total Fourier spectroscopy reflection (FTIR/ATR). For μTBS testing, 48 human third molars (n=8) were restored and sliced to obtain specimens (0.8 mm2) and they were tested at two different time intervals: immediately and after 6 months. The fracture mode was evaluated with a stereoscopic loupe (40×) and by scanning electron microscopy (SEM). The data were subjected to ANOVA and Tukey tests (a=0.05). NbG addition did not compromise the adhesive system DC values (p>0.05). Furthermore, the NbG added to the adhesive systems did not affect μTBS values (p>0.05). Fracture occurred predominantly at the dentin-adhesive interface. NbG bioactive glass did not affect the DC or microtensile bond strength results.

A review of bioceramics-based dental restorative materials

“…A total 20 studies [92][93][94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111] was found as per the inclusion criteria, whereby seven studies 92,[94][95][96]98,106,108) were based on fluoride-based bioactive glass (F-BAG). Few studies showed doping of zinc 101,102,107) , silver 110) , and niobiophosphate 109) in BAG powders. Experimental dental adhesives were also prepared by adding mineral trioxide aggregate (MTA) in BAG powder 103,104) .…”

Glass microparticle‐ versus microsphere‐filled experimental dental adhesives

“…This could be accounted for by the high degree of conversion obtained with a high glass percent where the intensity of the CuO peak would be high. The degree of conversion of the unfilled adhesive is similar to that obtained by Carneiro et al . It is, however, lower than that obtained by Ito et al .…”

Effect of an hydrophobic layer on a universal adhesive

“…Although this proposal involves an additional step that causes an increase in clinical time, it may protect the integrity of the adhesive interface over time. Other proposals, such as the use of sonic devices [8]; application of multiple layers [9] and use of bioactive substances [10,11]; are found in the literature, but their ability to maintain bond strength (BS) longevity has not been conclusively proved.…”