surface & subsurface damage in ceramic restorations - in
TRANSCRIPT
Ling Yin
Presented at the Department of Engineering Research Forum
June 6, 2007 ANU, Canberra
Surface & Subsurface Damage in Ceramic Restorations - In Vitro Study & Numerical Modeling
Intra-oral Conditions
Applied Load Ranges
Mastication 6 – 130 NMaximum 200 – 800 N
Cycles/day 1000 – 1400
Temperature Range 65°C
PH range 0.5 – 8.0
J R Kelly, Annu Rev Mater Sci 1997, 27, 443.
Why BioceramicsAestheticsBiocompatibilityChemical Durability
RequirementsEase of fabricationSufficient mechanical & corrosion resistance durabilityAppropriate aesthetic appeal
Restorative Processes for Dental Ceramics
Dental CeramicsAesthetics
BiocompatibilityChemical Durability
Dental CAD/CAMData Acquisition
Modeling & DesignCNC Machining
Handpiece FinishingMatching & Fitting
Surface IntegrityReplacement
Performance FatigueWear
Longevity
L Yin, X Song, Y Song, T Huang, J Li, Int J Machine Tool Manufact 2006, 46, 1013.
Dental Bioceramics Enamel MGC-C MGC-M MGC-Fine Macor Dicor Porcelain Empress 1Empress 2 Alumina Zirconia
Har
dnes
s (G
Pa)
0
2
4
6
8
10
12
14
16
Machinable Bioceramics
Difficult-to-Machine Bioceramics
L Yin, X Song, Y Song, T Huang, J Li, Int J Machine Tool Manufact 2006, 46, 1013.
Dental Bioceramics & Machinability
Tooth Feature-Based Posterior Crown DesignMesiodistal
Ridge
Dental Cusp
Dental Fossas
Ridge
Marginal Ridge
Grooves
Buccal Surface
Lingual Surface
Distal Surface
Mesial Surface
Central Groove
Marginal Ridge
Dental Cusp
Groove
Groove
Facio-lingual
(a)
Faciolingual Size
Bulge
Contact Area
Ridge
Contour
Distal Surface
Mesial Surface
Occlusal Surface
Cervico-occlusal
(b)
CervicalMargin
Length
Width
Feature of the Lower First Molar (J. B. Woelfel 1990)
(a) (b)
Scanned Points
Feature Points
Initial Data Points
Feature Point
Profile Feature Curve of Contour(a) (b)
Y Song, J Li, L Yin, T Huang, P Gao, Int J Adv Manufact Technol 2007, 31, 1058.
Intraoral Resurfacing Using Dental Handpieces
JADA
JADAhttp://www.ceramco.com/prod_cerconz_aacd.shtml
2-DOF Tester for In Vitro Dental Resurfacing
L Yin, X Song, S Qu, T Huang, J Mei, Z Yang, J Li, IMechE/H J Eng Med 2006, 220, 929.
In Vitro Dental Resurfacing Testing
L Yin, Y Han, X Song, H Wang, J Li, J Biomed Mater Res B, 2007, in press.
Surface Damage
L Yin, X Song, S Qu, Y Han, H Wang, J Biomed Mater Res 2006, 79B, 365.
(a) (b)
(c) (d)
Fracture
Smooth
Smeared
DebrisFracture
SmoothSmeared
Debris
Fracture
Smooth
Smeared
Debris
Fracture
Smooth
Smeared
Debris
Subsurface Damage
X Song, L Yin, Y Han, J Li, J Biomed Mater Res 2007, 79B, accepted.
FEA Modeling
X Song, L Yin, Y Han, J Li, J Biomed Mater Res 2007, 79B, accepted.
Summary 1. Computer-aided tooth feature-based posterior crown design
was developed. 2. A computer-assisted in vitro dental resurfacing apparatus
with 2-DOF was built, which enables the performance of precision-movement control of the dental handpiece and in-process measurement of force-related signals.
3. In vitro study of surface and subsurface damage was conducted, together with other intraoral resurfacing characteristics including handpiece rotational speed, force, torque, and energy.
4. FEA was applied for evaluation of stress distribution and for prediction of subsurface damage degrees.
