Effect of different repair methods on the bond strength of resin composite to CAD/CAM materials and microorganisms adhesion: An in situ study

Bonding performance of dispersed filler resin composite CAD/CAM blocks with different surface treatment protocols

“…Although HF does not directly affect zirconium, its peaks decreased because it was rinsed off together with the other elements which form the filler particles. These results are in agreement with the data reported for LAVA ultimate (DF-RCB) 27) . For En (PICN-RCB), both SB and HF resulted in a slight increase in carbon and oxygen peaks and no remarkable effect on aluminium, silicon and zirconium peaks.…”

“…Our results showed that the chemical pretreatment with S3 was capable to achieve higher µTBS than other chemical pretreatments. This corroborates the results of a previous study which evaluated the application of UAs to bur-roughened DF-RCBs and there was no significant difference with or without the application of a silane 27) .…”

“…It is noteworthy that the failure mode observation of the large grit size group revealed cohesive fractures in IVO block resulting from the superficial damage and the development of subsurface cracks after thermocycling 24) . In another study, roughening of DF-RCBs with a diamond bur increased the shear bond strength more than SB and HF 27) .…”

“…2). The roughening effect of HF depends on the RCBs inorganic filler size (micro/nanoscale) which can explain the insignificant change in the surface roughness resulted in previous studies when compared to the correspondent finished surface with SiC papers (#1000 and #1200 SiC) 11,27,31) . In this study, the RCBs surfaces were polished with diamond paste before the surface pretreatment for surface topographic evaluation aiming to elucidate the effect of HF etching.…”

“…SB with 50 µm alumina particles under a controlled air pressure of 0.1-0.2 MPa has been reported as the most effective method for bond durability 16) , but it may affect the fatigue strength and long-term durability of DF-RCBs 23,24) due to the development subsurface cracks (1-10 µm) 23) . To promote the chemical adhesion and bonding performance to DF-RCBs, some manufacturers and authors recommend a silane treatment prior to the cementation 17,25) , while others advocate the use of universal adhesives 26,27) . For PICN-RCBs, hydrofluoric acid (HF) is recommended as a pretreatment to roughen the surface and enhance mechanical interlocking.…”