Bending strength of ceramic compounds bonded with silicate-based glass solder

Abstract

In the field of dental technology, the length of ceramic pontics is limited to avoid mechanical failure. To reduce thermal-induced residual stress within the ceramic, using smaller subcomponents and subsequent bonding with silicate-based glass solder may be a favorable approach. Thus, the bending strength of zirconia compounds bonded with different silicate-based glass solders was investigated. For this purpose, rectangular specimens made of zirconia were bonded by glass solder. Parameters such as the scarf angle (45° and 90°), two different glass solders, as well as the soldering process (pressure and surface treatment) were varied. All specimens were subjected to quasi-static four-point bending tests according to DIN EN ISO 843-1. Additionally, the quality of the glass solder connection was evaluated using μCT and fractography. In the present study, zirconia compounds were sucessful bonded of zirconia compounds using silicate-based glass solder was. No significant differences in terms of bending strength were observed with respect to the different bonding parameters analyzed. The highest bending strength of 130.6 ± 50.5 MPa was achieved with a 90° scarf angle combined with ethanol treatment of the specimens before soldering and an additional application of a pressure of 2 bars in a dental pressure pot before subsequent soldering. Nevertheless, the bending strengths were highly decreased when compared to monolithic zirconia specimens (993.4 ± 125.5 MPa).

Fracture strength of monolithic and glass‐soldered ceramic subcomponents of 5‐unit fixed dental prosthesis

“…However, for the diagonal joint geometry and the vertical joint geometry with an occlusal cap, some specimens fractured in the soldered joint. As described by Sass et al, 20 a high‐quality standard of the joint is necessary to achieve a high bond strength. Air voids and misalignment of the subcomponents must be prevented and the joint surfaces must be homogeneously wetted with the glass solder.…”

“…Three joint geometries were introduced: diagonal joint geometry, vertical joint geometry with an occlusal cap, and a dental attachment‐based joint geometry. The preparation of the joint was done with standard equipment of a dental laboratory and according to a previously published method for joining Y‐TZP 20 …”

“…The preparation of the joint was done with standard equipment of a dental laboratory and according to a previously published method for joining Y-TZP. 20 Several studies have investigated the mechanical strength of three-unit FDP 11,25,[28][29][30] and four-unit FDP. 17,31 To the best of the author's knowledge, no experimental study has been performed with Y-TZP based 5-unit FDP.…”

“…The manufacturing process for the glass‐soldered joint was adopted from a previous study and consisted of surface preparation, cleaning, and soldering 20 . Within that study by Sass et al, 20 the influence of different surface treatments and ambient conditions on the soldered joint of rectangular specimens was investigated. Therefore, in this study, the joint surfaces were cleaned in an ultrasonic bath with ethanol and subsequently stored in ethanol for 30 minutes.…”

“…The silicate-based glass solder used in this study has shown promising results. 17 In a recent study, Sass et al 20 described a manufacturing method for the sufficient joining of Y-TZP subcomponents, which can be performed using the standard equipment of a dental laboratory and a silicate-based glass solder. However, the investigation was restricted to rectangular bars and no complex-shaped parts have been joined with the described method yet.…”