pH changes of self-etching primers mixed with powdered dentine

Influence of oxygen inhibition on the surface free energy and enamel bond strength of self-etch adhesives

“…A previous report focusing on the effects of self-etching primers on the continuous demineralization of dentin showed that the etching effect of the acidic functional monomer was not stopped by the polymerization of the adhesives. Residual acid could be consumed and neutralized by a reaction with hydroxyapatite from the dentin substrate 30) . The current study suggested that the presence of an oxygen-inhibited layer in single-step self-etch adhesives promoted higher enamel bond strength.…”

Influence of powdered dentin on the shear bond strength of dentin bonding systems

“…However, these acidic functional monomers that modify the smear layer and demineralize dentin are not rinsed off after application. This means prolonged contact of the acidic functional monomers with the dentin substrate, and hence prolonged demineralization of dentin 9) . Besides, incomplete resin infiltration was observed in some self-etch adhesives due to the reduced etching potential of acidic monomers toward the base of hybrid layers 24) .…”

“…Maeda et al 9) reported that dentin powder (particle size<60 µm) had a strong buffering capacity against the acidity of self-etching primers because their pH values significantly increased, ranging from 6.95 to 7.37, after mixing with dentin powder. Similarly, Iwasa et al 10) reported that after adding dentin powder to singlestep self-etch adhesives, their pH values significantly increased, ranging from 6.30 to 7.11.…”

“…Moreover, self-etch primers are not rinsed away after application -permitting further direct interaction between the acidic functional monomers and the dentin substrate, and hence continuous demineralization of dentin 3) . According to Maeda et al 9) and Iwasa et al 10) , dentin has a strong buffering capacity and modulation effect against the acidity of self-etch primers. Thus, it was proposed to incorporate powdered dentin into selfetching primers 9,10) to neutralize any continuing etching 11,12) .…”

“…According to Maeda et al 9) and Iwasa et al 10) , dentin has a strong buffering capacity and modulation effect against the acidity of self-etch primers. Thus, it was proposed to incorporate powdered dentin into selfetching primers 9,10) to neutralize any continuing etching 11,12) . To improve bonding strength, fillers have been added to adhesives to increase the thickness of the hybrid layer and to reinforce the hybrid layer against thermal and mechanical stresses [13][14][15][16][17][18][19][20] .…”