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

DIY Methods 2022 Conference Proceedings

As the past years have proven, the methods for conducting and distributing research that we’ve inherited from our disciplinary traditions can be remarkably brittle in the face of rapidly changing social and mobility norms. The ways we work and the ways we meet are questions newly opened for practical and theoretical inquiry; we both need to solve real problems in our daily lives and account for the constitutive effects of these solutions on the character of the knowledge we produce. Methods are not neutral tools, and nor are they fixed ones. As such, the work of inventing, repairing, and hacking methods is a necessary, if often underexplored, part of the wider research process. This conference aims to better interrogate and celebrate such experiments with method. Borrowing from the spirit and circuits of exchange in earlier DIY cultures, it takes the form of a zine ring distributed via postal mail. Participants will craft zines describing methodological experiments and/or how-to guides, which the conference organisers will subsequently mail out to all participants. Feedback on conference proceedings will also proceed through the mail, as well as via an optional Twitter hashtag. The conference itself is thus an experiment with different temporalities and medialities of research exchange. As a practical benefit, this format guarantees that the experience will be free of Zoom fatigue, timezone difficulties, travel expenses, and visa headaches. More generatively, it may also afford slower thinking, richer aesthetic possibilities, more diverse forms of circulation, and perhaps even some amount of delight. The conference format itself is part of the DIY experiment

Non-homogeneous boundary value problems for the Korteweg–de Vries and the Korteweg–de Vries–Burgers equations in a quarter plane

Attention is given to the initial-boundary-value problems (IBVPs) ut + ux + uux + uxxx = 0, for x, t ≥ 0, u(x, 0) = φ(x), u(0, t) = h(t) for the Korteweg-de Vries (KdV) equation and ut + ux + uux − uxx + uxxx = 0, for x, t ≥ 0