Dentin pretreatment with 45S5 and niobophosphate bioactive glass: Effects on pH, antibacterial, mechanical properties of the interface and microtensile bond strength

The use of bioactive particles and biomimetic analogues for increasing the longevity of resin-dentin interfaces: A literature review

“…However, the mechanical properties at the adhesive (i.e., bonding resin) layer decreased in most of the groups, possibly due to hydrolytic degradation of the polymer 20,36) . Increases in elastic modulus of the hybrid layer after three months in PBS were also observed with suspensions containing Niobium-based glass or 45S5 BAG particles 25) or zincloaded polymeric nanoparticles 31) applied as primers on demineralized dentin, followed by the application of a commercial adhesive.…”

“…The incorporation of ion-releasing particles in experimental adhesives shows inconsistent results on the long-term bond strength to dentin. While studies evaluating adhesives containing BAG, CaSi-based or ZnO particles, as well as primers consisting of glass suspensions reported no loss in microtensile bond strength after three or six months of storage (as opposed to the control groups without particles) 19,25,28,29) , others did not find differences between adhesives containing particles and the unfilled controls 21,24,27,35,36) . A study comparing the application of BAG particles to the demineralized dentin surface before the adhesive application or added to the adhesive (30 wt%) led to different outcomes after six months in PBS.…”

“…Ion-releasing ("bioactive") particles have been tested as additives in experimental [18][19][20][21][22][23] and commercial adhesives 24) . Also, they have been applied to acid-etched dentin prior to adhesive application 19,25,26) or used in airabrasion systems for selective caries removal 27) . The purpose of adding these particles in adhesive procedures is two-fold: besides replacing the lost mineral within the collagen network, metallic ions protect the collagen fibrils from degradation by reducing collagenase activity 28) .…”

“…Among the silicabased BAG, the original 45S5 Bioglass, developed by Hench in the late 1960's 33) , is the composition most commonly tested, either unmodified 18,19) , doped with zinc 20,21) , copper 34) , fluoride 22) or treated with polyacrylic acid (PAA) 27) . Other compositions have been tested, including Niobium-based glass 24,25) and a silica-based glass with higher Ca:P molar ratio than 45S5 23) .…”

“…Several mechanisms have been proposed to explain the reduced collagen degradation observed in demineralized dentin samples infiltrated or in contact with adhesives containing ion-releasing particles, which can be briefly described as follows: 1) ions released from the glass particles can bind to specific sites on the exposed collagen fibrils and modify its spacial configuration, protecting sensitive cleavage sites 39) ; 2) Electrostatic interactions between MMP-2 or MMP-9 and CaP precipitates form high molecular weight, low-mobility aggregates, reducing enzymatic activity 40) ; 3) HA was shown to inactivate MMP-1 and MMP-3 in bone 41) ; 4) local alkalinization promoted by ion release (Ca 2+ , Na + ) 22,25) is likely to down-regulate MMP activity, normally triggered in acidic conditions 42) .…”