Mimicking and Measuring Occlusal Erosive Tooth Wear with the "Rub&Roll" and Non-contact Profilometry

Summary

The Rub&Roll can mimic the chewing cycle, allowing variation of chewing force, sliding distance, chewing velocity, number of cycles, and frequency, and with a combination of erosive and abrasive challenges can result in a complex simulation of oral ageing.

Abstract

Chewing, drinking, and occasional tooth grinding will result in physiological tooth wear during a lifetime. Extreme challenges, such as bruxism or habitual chewing on foreign objects, may lead to excessive wear. Recently, the role of erosion in accelerating mechanical tooth wear has been recognized, but the interplay between chemical and mechanical wear processes has not been extensively studied. Our laboratory recently introduced a novel oral wear simulation device, the Rub&Roll, that enables the user to perform wear and loading studies separately or simultaneously in an erosive and/or abrasive environment. This manuscript describes an application of the device: the combined mechanical and erosive loading of extracted human (pre)molars in a simulated chewing movement, with a controlled application of force, velocity, fluid, and time, and the application of non-contact profilometry in visualizing and measuring the resulting wear pattern. The occlusal morphology that was created in the experiment with the highest loading level is very similar to the clinical presentation of erosive wear.

Introduction

The oral cavity could be considered a harsh environment: humidity, temperature changes due to hot and cold food intake, and mechanical loading with some of the strongest muscles in the human body. Teeth, however, are eminently equipped to withstand these challenges. The enamel is very hard, and the dentin underneath prevents the relatively brittle enamel from fracturing. The mineral component of both materials, hydroxyapatite is of very low solubility and in equilibrium with the supersaturated saliva. Chewing, drinking, and occasional tooth grinding will result in physiological tooth wear during a lifetime^1,2<....

Protocol

Collection of the teeth used in this experiment was performed in accordance with the guidelines of the regional Medical Ethics Committee.

1. Specimen Collection and Sample Preparation

1. Collect 24 sound extracted human (pre)molars from dental practices, and brush with pumice in a low-speed handpiece to a clean (no debris, no gingival remnants) and smooth tooth surface, and finally rinse for 15 s under running tap water.
2. Embed the samples to make them fit into the recesses (12 mm x 15 mm x 27.5 mm) of the cylinder of the device.
   1. Melt the impression compound (one stick of 113 g) on a hotplate (50 °C) for a....

Results

We exposed human molar teeth (n = 8 per group) to an acidic aqueous solution at pH 4.8 in the Rub&Roll, for 3 months. This corresponds to a clinical functioning time of about 6 years. The mechanical load applied was: no load (0 N), 30 N, or 50 N.

Mean occlusal surface height loss for the three groups was: 76 ± 20 µm for 0 N; 161 ± 40 µm for 30 N; and 266 ± 101 µm for 50 N (Figure 2). The erosive.......

Discussion

The application presented here gives a good impression of the clinical relevance of the Rub&Roll. The occlusal morphology that was created in the experiment with the highest loading level is very similar to the clinical presentation of erosive tooth wear (Figure 5)^11,12.

The versatility of the set up lies first of all with the solutions used. In the simplest model, water may be used. Loading samples in.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Low speed handpiece	KAVO, Leutkirch imm Allgau, Germany		Dental equipment
Brush for handpiece	KAVO, Leutkirch imm Allgau, Germany		Dental equipment
Pumish			Dental equipment
Human third molars
Impression compound green	Kerr, Bioggio, Switzerland	Art.nr. 00444
Microscope slide	Menzel, Braunschweig, Germany		76 x 26 mm
Autoplast Cold curing denture base material	Candulor, Wangen, Switzerland
Silicone mold with inside dimensions of 12 x 15 x 27.5	3M Espe Neuss, Germany	Express STD
Pressure vessel	Al Dente, Meckenbeuren, Germany	581-009-024/25
Milling cutter ø16mm	Format, Germany	HSSCo8 nr. 21691600
Milling machine	Weiss Machine Tools	WMD 20 LV
Rub&Roll	UMCN , Nijmegen The Netherlands		Technical workshop
Rub&Roll container	UMCN , Nijmegen The Netherlands		Technical workshop
Rub&Roll cylinder sample holder	UMCN , Nijmegen The Netherlands		Technical workshop
Rub&Roll motor	UMCN , Nijmegen The Netherlands		Technical workshop
Shim: Silicone plate massive 1 mm/ 1,5mm, 60 ± 5° Shore A, red	Peter van den Berg afdichtingstechniek, Barendrecht
Lactid acid extra pure 88%	Boom, The Netherlands	CAS nummer: 79-33-4
Calcium Chloride dihydrate CaCL2 .2H2O	Merck, Darmstadt, Germany	CAS nummer: 10043-52-4
Pottassium dihydrogen Phosphate KH2PO4	Merck, Darmstadt, Germany	CAS nummer: 7778-77-0
Chloramine T (sodium salt) trihydrate for synthesis CH3C6H4SO2NClNa·3H2O	Merck, Darmstadt, Germany	CAS nummer: 7080-50-4
Natriumfluoride standard solution 1000mg/L F Certipur	Merck, Darmstadt, Germany	CAS nummer: 7681-49-4
Deionized water
Kaliumhydroxide, pellets EMSURE analytical reagent KOH	Merck, Darmstadt, Germany	CAS nummer: 1310-58-3
PVC tube(Hardness73 Shore A)outer diameter 14mm inner diameter 10mm	DEUTSCH & NEUMANN, Germany	Art.nr. 3501014
Insert of a stainless steel 316 (Hardness 130–150 HB) diameter 9mm	UMCN , Nijmegen The Netherlands		Technical workshop
pH glass electrode	WTW, Weilheim, Germany	Sentix 61 103640
Non contact Profilometer Proscan 2100	Scantron Industrial Products Ltd, Taunton, UK		http://www.scantronltd.co.uk
Software version Proscan 2100 2.1.1.15A+ Sensor S29 / 10-10000 microns	Scantron Industrial Products Ltd, Taunton, UK
Software version Proform	Scantron Industrial Products Ltd, Taunton, UK
Stereomicroscope Leica	www.leica-microsystems.com	M50
Photocamera Canon	Canon Japan	EOS 50D
Syringe	BD Plastipak, Spain	20 ml.
Hotplate	Schott instruments Mainz	SLK1
Silone impression material (Vinyl Polysiloxane Expres)	3M Espe , USA	Regular
Stirring Plate	IKA Werke, Germany	KMO2 Basic