Dental abrasion as a cutting process
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2016-04-22 |
| Journal | Interface Focus |
| Authors | Peter W. Lucas, Mark Wagner, Khaled J. AlâFadhalah, Abdulwahab S. Almusallam, Shaji Michael |
| Institutions | Max Planck Institute for Evolutionary Anthropology, University of Reading |
| Citations | 11 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Dental Abrasion as a Cutting Process
Section titled âTechnical Documentation & Analysis: Dental Abrasion as a Cutting ProcessâThis document analyzes the research paper âDental abrasion as a cutting processâ (Lucas PW et al. 2016) to identify key technical requirements and demonstrate how 6CCVDâs specialized MPCVD diamond materials and services can support and advance research in biomechanics, tribology, and biomaterials wear testing.
Executive Summary
Section titled âExecutive Summaryâ- Core Finding: Dental abrasion is fundamentally analyzed as a micro-cutting process, allowing the application of fracture mechanics theory to estimate material toughness.
- Material Property Measured: The toughness (R) of human enamel in cutting was determined to be exceptionally high, estimated at 244 J m-2, suggesting significant inherent resistance to abrasive wear.
- Methodology: Experiments relied on highly controlled scratch testing using ultra-hard indenters, specifically a Berkovich diamond tip and a tungsten carbide blade, coupled with multi-axial load sensing.
- Damage Analysis: Atomic Force Microscopy (AFM) confirmed that damage mechanisms include both plastic deformation (prowing) and brittle fracture (lateral microcracks).
- Tribological Impact: The presence of polyphenolic compounds (tannins) significantly increased friction against the enamel surface, indicating a potential mechanism for increased wear in natural diets.
- 6CCVD Relevance: The research necessitates the use of ultra-precision, ultra-hard materials (diamond) for tooling and reference substrates, directly aligning with 6CCVDâs expertise in MPCVD Single Crystal Diamond (SCD) and Polycrystalline Diamond (PCD).
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results and discussion:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Enamel Toughness (R) | 244 | J m-2 | Estimated via cutting mechanics using Berkovich diamond. |
| Maximum Vertical Load (Ft) | 4000 | ”N | Largest fixed normal force applied during scratch test. |
| Minimum Vertical Load (Ft) | 250 | ”N | Lowest fixed normal force applied during scratch test. |
| Maximum Cutting Force (Fc) | 1750 | ”N | Measured sliding force corresponding to 4000 ”N load. |
| Berkovich Tip Half-Angle | 65.3 | ° | Geometry of the primary diamond indenter used. |
| Tungsten Carbide Rake Angle | 22 | ° | Geometry of the blade used for comparative cutting. |
| Estimated Shear Yield Stress (Ïy) | 1.48 | GPa | Derived from cutting analysis of enamel. |
| Enamel Hardness (Reference) | 5.5 | GPa | Referenced value for nanoindentation hardness. |
| Friction Modifier Concentration | 0.1 | M | Epigallocatechin gallate (polyphenolic compound) concentration. |
| Groove Depth Elastic Recovery | ~50 | % | Observed elastic recovery of the groove depth post-load. |
Key Methodologies
Section titled âKey MethodologiesâThe experimental approach focused on highly controlled, small-scale cutting tests using specialized instrumentation:
- Sample Preparation: Human enamel samples were embedded in resin and polished to a 1 ”m finish to ensure a smooth, consistent testing surface.
- Instrumentation: A custom-built, multi-axial load peripheral tester was utilized, incorporating a Nano 17 Multiaxial Load Cell (ATI Industrial Automation) for precise force measurement (down to 0.01 N).
- Cutting Tooling:
- Berkovich Diamond Indenter: Used for consistent groove cutting, featuring a 65.3° half-angle.
- Tungsten Carbide Blade: Used in initial experiments, featuring a 22° rake angle.
- Cutting Protocol: Fixed vertical loads (Ft) were applied, and the tip was translated across the surface at a constant speed (not explicitly stated, but implied by time plots) to create grooves.
- Tribological Testing: Experiments were conducted under three conditions to assess friction: dry, with a salivary coating, and with saliva plus a polyphenolic compound (0.1 M epigallocatechin gallate).
- Data Acquisition: Displacement and cutting forces (Fc) were recorded against time.
- Surface Metrology: Post-test analysis relied heavily on Atomic Force Microscopy (AFM) to image the resulting grooves, measure groove depth, and characterize damage (prowing, microcracks).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research highlights the critical need for materials with extreme hardness, precision geometry, and superior surface finishâareas where 6CCVD excels. We provide the necessary components to replicate, calibrate, and extend this cutting-edge tribology research.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate the ultra-hard tooling used in this study or to establish the ultimate reference standard for wear resistance, 6CCVD recommends the following MPCVD diamond materials:
- Single Crystal Diamond (SCD) Tooling Blanks:
- Application: Ideal for manufacturing next-generation Berkovich or custom-geometry indenters, offering hardness and thermal stability far exceeding tungsten carbide.
- Specifications: Available in thicknesses from 0.1 ”m up to 500 ”m, providing the highest possible material purity and consistency for metrology standards.
- Optical Grade SCD Substrates:
- Application: For use as ultra-low wear reference surfaces in tribology rigs, ensuring that any measured wear is solely attributable to the counter-material or lubricant.
- Polishing: 6CCVD guarantees an ultra-smooth surface finish of Ra < 1 nm, essential for high-resolution AFM imaging of micro-scale wear tracks.
- Polycrystalline Diamond (PCD) Wafers:
- Application: For large-area wear studies or creating custom, inch-sized tribological test platforms where high hardness and large dimensions are required.
- Specifications: Available in plates/wafers up to 125 mm diameter, with polishing down to Ra < 5 nm.
Customization Potential
Section titled âCustomization PotentialâThe precision required for micro-cutting experiments often demands unique material integration and geometry. 6CCVD offers comprehensive customization services:
| Requirement from Research | 6CCVD Custom Solution | Benefit to Researcher |
|---|---|---|
| Custom Indenter Geometry | Supply of SCD blanks for custom laser cutting and shaping of non-standard cutting tips (e.g., specific rake angles beyond 22°). | Enables precise control over attack angle and tip radius for advanced cutting mechanics modeling. |
| Sensor Integration | Custom metalization services (Au, Pt, Ti, W, Cu) on diamond substrates. | Allows integration of diamond wear surfaces with micro-sensors or heating elements for in situ monitoring of friction and temperature effects. |
| Precision Substrates | Custom thickness SCD/PCD substrates (0.1 ”m to 10 mm) cut to exact dimensions required by specialized multi-axial load cells. | Ensures seamless integration into existing nano-tribology and scratch testing equipment. |
Engineering Support
Section titled âEngineering SupportâThe analysis of wear mechanisms, fracture toughness (R), and the transition between plastic deformation and brittle fracture requires deep expertise in materials science.
6CCVDâs in-house PhD team specializes in the mechanical and electronic properties of CVD diamond and can assist researchers with material selection and experimental design for similar Tribology and Biomechanics projects. We offer consultation on:
- Optimizing diamond material grade for specific hardness or thermal requirements.
- Designing custom diamond tooling for high-load or high-speed cutting applications.
- Interpreting results where diamond is used as a reference standard for ultra-low wear.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We offer global shipping (DDU default, DDP available) to ensure your research materials arrive quickly and reliably.
View Original Abstract
A mammalian tooth is abraded when a sliding contact between a particle and the tooth surface leads to an immediate loss of tooth tissue. Over time, these contacts can lead to wear serious enough to impair the oral processing of food. Both anatomical and physiological mechanisms have evolved in mammals to try to prevent wear, indicating its evolutionary importance, but it is still an established survival threat. Here we consider that many wear marks result from a cutting action whereby the contacting tip(s) of such wear particles acts akin to a tool tip. Recent theoretical developments show that it is possible to estimate the toughness of abraded materials via cutting tests. Here, we report experiments intended to establish the wear resistance of enamel in terms of its toughness and how friction varies. Imaging via atomic force microscopy (AFM) was used to assess the damage involved. Damage ranged from pure plastic deformation to fracture with and without lateral microcracks. Grooves cut with a Berkovich diamond were the most consistent, suggesting that the toughness of enamel in cutting is 244 J m â2 , which is very high. Friction was higher in the presence of a polyphenolic compound, indicating that this could increase wear potential.