Comprehensive analysis of laserscanner validity used for measurement of wear

Abstract

Summary Objectives The aims of this study were to test the hypotheses that (a) a laserscanner used for measuring maximum depth and volume loss will yield the same results as a surface profilometer; (b) the surface roughness will affect the maximum depth and volume loss measured with the laserscanner; (c) analytical results using the laserscanner from multiple operators have no more than 10% inter‐rater difference and; (d) replicating samples using either stone or impression material is an accurate method for measuring wear using the laserscanner. Materials and Methods The volume and maximum depth of indentations from fine, medium and rough burs on glass‐ceramic disks were measured using two devices, a surface profilometer (Dektak II, Veeco) and a 3D Laserscanner (LAS‐20, SD Mechatronik). Replicates of the indentations made from polyvinysiloxane impression material and gypsum were also measured. Results Comparison of profilometer and laserscanner readings using ceramic disks demonstrated a mean error of 13.61% for depth and 25.32% for volume. Replication errors were minimal (2.6% for impression, 2.5% for stone). Surface profilometer data for volume measurements revealed a difference of 6.1% for impression and 6.5% for stone compared with ceramics. However, when measurements for replicates were compared between laserscanner and surface profilometer, depth had a mean error of 74% for impression and 51% for stone. Volume differences of 78% for impression and 44% for stone were recorded. Conclusion This work demonstrated that the laserscanner was a convenient device for measuring wear but there is a need to validate the accuracy of the measurements.

Novel methodology for measuring intraoral wear in enamel and dental restorative materials

“…More recently, the assessment of in vivo wear has been conducted using laser scanner technology or profilometry with tooth replicates either in acrylic resin or stone (Heintze, Cavalleri, Forjanic, Zellweger, & Rousson, 2006;Mehl, Gloger, Kunzelmann, & Hickel, 1997;Pintado, Anderson, DeLong, & Douglas, 1997;Rodriguez & Bartlett, 2010;Rodriguez, Curtis, & Bartlett, 2009;Schlueter, Ganss, Sanctis, & Klimek, 2005). While this has proven to be effective, there are some errors involved in the replication process with the impression and the replicating materials (Hsu et al, 2019;Rodriguez & Bartlett, 2010;Segerström, Wiking-Lima de Faria, Braian, Ameri, & Ahlgren, 2018). Also, the resolution accuracy of the laser scanners varies from 5 to 20 μm and can affect the quantification of wear.…”

Measurement of Tooth Wear by Means of Digital Impressions: An In-Vitro Evaluation of Three Intraoral Scanning Systems

“…After all scans at t0 were accomplished, wear areas were manually simulated using a diamond-bur (Ø1.2 mm, grit size 46 µm) [11]. In total, three stages of wear (t1-t3) were created successively at tooth 26 mesio-oral and tooth 27 disto-buccal (Figure 2).…”