Anin vitrostudy to evaluate the effect of storage time and application of subsequent layers on the variation in thickness of three commercially available die spacers

Abstract

There was a definite variation in the thickness of the die spacer with all the three brands and at various points on the die. Two coat thicknesses were found to be in the range of tolerance of 20-40 microns. Thickness at occlusal groove was noted to be the maximum with least at occlusoaxial line angles. Thickness also showed a very significant increase when bottles were stored for a period of three to six months and then applied.

The Effect of Milling Metal Versus Milling Wax on Implant Framework Retention and Adaptation

“…According to Hager et al, one of the factors that could improve the marginal and internal adaptation is increasing the cement space at the axio‐occlusal line angles . The recommended amount of internal relief for optimal adaptation is 25 to 40 μm . This indicates that the thickness of the cement space (within the recommended range) could be influenced by the framework fabrication method, or that the thickness of cement space could compensate for some of the shortcomings related to the fabrication process …”

“…In the first group, the abutment analogs were scanned using a laser scanner after being sprayed with reflective scan powder (VITA CEREC; Vita Zahnfabrik, Bad Sackingen, Germany), according to the manufacturer's instructions. The cement space was considered to be 30 μm on the abutment analogs, extending to within 0.5 μm of the margins . The patterns were designed (CORiTEC450i; imes‐icore GmbH, Eiterfeld, Germany), and the wax patterns were milled (Yeti; Dentalprodukte, GmbH, Engen, Germany), sprayed, and invested in phosphate‐bonded investment (Z4‐C&B investment; Neirynck & Vogt, Schelle, Belgium) at a ratio of 24 ml liquid to 100 mg powder.…”

“…The frameworks were designed (imes‐icore GmbH) and milled from sintered Co‐Cr metal blocks (4all). The milling process was performed using a milling machine with 5 axes (Cori TEC 450i) using a 30 μm cement space 0.5 mm coronal to the abutment analog margins . Additionally, a ring‐like process (5 mm diameter) was cast and soldered in the center of the occlusal surface on all frameworks in groups 1 and 2, to allow attachment to the universal testing machine to test their tensile resistance.…”

Fracture Resistance of Lithium Disilicate Ceramics Bonded to Enamel or Dentin Using Different Resin Cement Types and Film Thicknesses

“…As a result of the manufacturing process, mean cement film thicknesses of 106.74 μm for the pressable technique and 340.35 μm for the machinable CAD/CAM technique were observed . Further, variations in finger pressure during cementation procedures, coupled with die spacer application, could generate a layer thickness of more than 100 μm …”

Clinical Acceptability of the Internal Gap of CAD/CAM PD-AG Crowns Using Intraoral Digital Impressions

“…The luting space of CAD/CAM Pd-Ag crowns was set at 25  μ m. For fabrication of gold crowns, two coats of die spacer (Pico-Fit; Renfert) were applied on the casts. The mean thickness of the die spacer was expected to be about 25  μ m [24]. The wax pattern was created by the convention method of using a dipping wax (elaflex, Brident).…”