Comparison of the shear bond strength of 3D printed temporary bridges materials, on different types of resin cements and surface treatment

Thus, purpose of this study was to compare the shear bond strength of the resin cement and the resin modified glass ionomer cement on 3D printed temporary material for crowns and bridges in combination with different surface treatment modalities. Test specimens VarseoSmile Temp material (Bego, Bremen, Germany) (n=64) in the form of rectangular blocks (n=32) and cylindrical test specimens (n=32) were printed using the Varseo S 3D printer (Bego, Bremen, Germany). The specimens were divided into 4 groups, with 8 specimens of each kind. Two groups (n=16 pairs) were blasted with Perlablast® Micro [PM] 50µm (Bego, Bremen, Germany) and two groups (n=16 pairs) were blasted with alumina [AL] 50µm. The cylindric specimen were cemented on the rectangular block with a load of 20N using a Zwick/Roell machine (Ulm, Germany), to ensure a comparable cementing process. One group (n=8) of each pre-treatment was cemented with Fuji Cem 2 [Fuji+AL & Fuji+PM] and one of each with Variolink® Esthetic [Vario+AL & Vario+PM]. The Fuji Cem 2 was chemically cured while dual curing Variolink® Esthetic was additionally light cured using LED (Bluephase II, Ivoclar Vivadent, Ellwagen, Germany; light intensity, >1,000 mW/cm2, high power modus). The shear strength was performed with Zwick/Roell universal test machine (speed, 0.8 mm/min), fracture and statistical analysis was performed (T-test, p<0.05). T-test showed a significant difference Fuji Cem 2 (Fuji+AL & Fuji&PM) and Variolink® Esthetic (Vario+AL &Vario+PM) (p=0.000). Fuji+AL & Fuji+PM showed a significant difference for surface pre-treatment (p=0.002). Vario+AL & Vario+PM no significance (p=0.872) for pre-treatment method was detectable. Variolink® Esthetic showed a higher bond strength compared to Fuji Cem 2 and an increasing bond strength for Fuji Cem 2 with alumina pre-treatment. There was no significant difference for Vario+AL and Vario+PM

Does inhibition of proteolytic activity improve adhesive luting?

Endogenous enzymes may be involved in the biodegradation of adhesive restoration-tooth interfaces. Inhibitors of matrix metalloproteinases (MMPs) have been suggested to retard the bond-degradation process. Limited data are available on whether composite cements may also benefit from MMP inhibitors. Therefore, the aim of this study was to determine the effect of two MMP inhibitors--chlorhexidine digluconate (CHX) and galardin--on the microtensile bond strength (μTBS) of two self-adhesive composite cements to dentin. Ceramic specimens were cemented to bur-cut dentin surfaces using the self-adhesive composite cements RelyX Unicem 2 (3M ESPE) or Clearfil SA (Kuraray), or the etch-and-rinse composite cement Nexus 3 (Kerr) that served as the control. The surfaces were left untreated or were pretreated with MMP inhibitors (2% CHX or 0.2 mM galardin). The μTBS was determined 'immediately' and upon ageing (water storage for 6 months). Statistical analysis revealed a significant effect of the factors 'composite cement' and 'storage', as well as all interactions, but no effect of the MMP inhibitors. After 6 months of ageing, the μTBS decreased for all cements, except for the multistep etch-and-rinse luting composite when it was applied without MMP inhibitors. The MMP inhibitors could not prevent the decrease in μTBS upon ageing and therefore do not improve the luting durability of the composite cements tested.status: publishe

Curing mode affects bond strength of adhesively luted composite CAD/CAM restorations to dentin

To determine the effect of curing mode and restoration-surface pre-treatment on the micro-tensile bond strength (μTBS) to dentin.publisher: Elsevier articletitle: Curing mode affects bond strength of adhesively luted composite CAD/CAM restorations to dentin journaltitle: Dental Materials articlelink: http://dx.doi.org/10.1016/j.dental.2013.11.016 content_type: article copyright: Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.status: publishe

Potential smear layer interference with bonding of self-etching adhesives to dentin

To evaluate the effect of smear-layer interposition on the bonding effectiveness of self-etching adhesives with different etching potential.status: publishe

Interfacial fracture toughness of aged adhesive-dentin interfaces

To assess interfacial fracture toughness of different adhesive approaches and compare to a standard micro-tensile bond-strength (μTBS) test after 6 months water storage.publisher: Elsevier articletitle: Interfacial fracture toughness of aged adhesive–dentin interfaces journaltitle: Dental Materials articlelink: http://dx.doi.org/10.1016/j.dental.2015.01.017 content_type: article copyright: Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.status: publishe

Hydrolytic stability of three-step etch-and-rinse adhesives in occlusal class-I cavities

Objectives A dental adhesive without small and hydrophilic monomers such as HEMA and TEGDMA would be beneficial in order to avoid contact allergies. However, these monomers are important to increase infiltration and polymerization of the adhesive. Therefore, the purpose of this study was to evaluate the bonding effectiveness and bond durability of a more hydrophobic and biocompatible adhesive as compared to a conventional three-step etch-and-rinse adhesive. Methods Sixteen non-carious human third molars were used to determine the micro-tensile bond strength testing (μTBS) and interfacial ultrastructure by transmission electron microscopy (TEM) of the more hydrophobic cmf adhesive system (Saremco) adhesive as compared to the control OptiBond FL (Kerr). Results The more hydrophobic and biocompatible three-step etch-and-rinse adhesive was able to produce a reasonable short-time bonding effectiveness. On the long-term, the collagen fibrils in the hybrid layer were not effectively protected and were prone to hydrolytic degradation. As a result, long-term bonding effectiveness of this novel adhesive was very low. Conclusions Application of a more hydrophobic adhesive without altering the application procedure considerably results in a reduced durability of the created bond Clinical relevance Omitting small and hydrophilic components from the adhesive formulation may impair the durability of your composite restoration.status: publishe