Thermal Properties in Dental Biomaterials & Zirconia Ceramic.pptx

Discusses thermal properties in dental biomaterials, their importance, zirconias strengths and clinical implications

1. Thermal Properties in Dental Biomaterials & Zirconia Ceramic Dental Biomaterials |BIOM221|CRN:10838 Doctor Ahmed Abyad By Rami Farhat| ID:202601520

2. What are Thermal Properties? They are physical properties of a material based on laws of thermodynamics that are related to how that material (dental biomaterial) responds upon receiving or losing heat. [1] ( Buck, W., Rudtsch, S., 2011)

3. Thermal Conductivity (k) A material's ability to transfer heat throughout itself Its Heat transfer rate Q( cal or j) past a thickness d (cm) along area( cm² ) A for a temperature change Δ T(1°C) from one point to the other Polymers<Ceramics<Metals [3](Anusavice , K. J., Shen, C., & Rawls, H. R.,2013, p. 39) [2] (Osman , n.d , p.10) [2] (Osman, n.d , p.10)

4. Specific Heat (Capacity) It refers to how much heat is needed to increase the temperature of 1g of the material by 1 °C The lower the specific heat , the easier it can gain or lose heat Examples: [2] (Osman , n.d , p.10) [2] (Osman, n.d , p.10) [4] (Tec-Science,2020 ) High Specific Heat Low Specific Heat

5. Thermal Diffusivity It is how fast a temperature change can go throughout a material Higher Conductivity → Higher Diffusivity Higher Density & Specific H eat →Lower Diffusivity D etermines the heat transferred to pulp and oral tissue [2] (Osman , n.d , p.10) [ 3](Anusavice, K. J., Shen, C., & Rawls, H. R.,2013, p. 39)

6. Thermal Expansion ( α ) Materials contract upon cooling and expand upon heating Temperature ↑ →Kinetic energy ↑ → Interatomic bond distance ↑ → Volume ↑ Described by its coefficient α which is the difference/change of length per original length when heated by 1 °C [2] (Osman , n.d , p.10) [ 3](Anusavice, K. J., Shen, C., & Rawls, H. R.,2013, p. 40)

7. Criteria for Dental Material Conductivity: Low Specific Heat : High Diffusivity: Low Thermal Expansion Coeff .: Close to enamel’s & dentin’s [ 3](Anusavice, K. J., Shen, C., & Rawls, H. R.,2013, p. 39-40) Property Thermal Conductivity (W.m⁻¹.k⁻¹) Specific Heat (J.kg⁻¹.k⁻¹) Thermal Diffusivity ( x10⁻⁶ m ² /s) Thermal Expansion (x10⁻⁶.K⁻¹) Desired Range 0.2-2 ≥700 0.1-1 8-17 Zirconia Ceramic 2-3 400-600 0.4-0.6 10-11 Comparative Table of Zirconia Ceramic [5] (Lancaster et al, 2017) [6] ( Niu et al,2016) [7] ( An, K. J. ,2013) [8] (Limarga,2012) [9] Coefficient of Thermal Expansion in Ceramics. Dimensional Stability Under Heat , n.d. )

8. What is Zirconia Ceramic? 8 Zirconium Dioxide (ZrO2) is a ceramic stabilized with Y2O3 used as an indirect restoration Great in Thermal and other physical & mechanical properties Examples in Dentistry: Crowns Bridges Implants Veneers [10](Bona et al,2015)

9. What If Materials Used D on’t Meet the Criteria https://www.dentsplysirona.com/en-ae/discover/discover-by-topic/by-category/restorative/microleakage.html [11] ( Themes,2015) [ 12] ( Cencei et al,2008) [13] ( Manjot et al,2015)

10. Restoration Failure & Patient Dissatisfaction [ 10] ( Themes,2015) [11] ( Cencei et al,2008) [12] ( Manjot et al,2015)

11. References [1] Buck , W., Rudtsch , S. (2011). Thermal Properties. In: Czichos , H., Saito, T., Smith, L. ( eds ) Springer Handbook of Metrology and Testing. Springer Handbooks. Springer, Berlin, Heidelberg. https:// doi.org/10.1007/978-3-642-16641-9_8 [2] Essam Osman, Essentials of Dental Materials, N.D, Faculty of Dentistry- University of Alexandria [3] Anusavice , K. J., Shen, C., & Rawls, H. R. (2013). Phillips' science of dental materials (12th ed.). Saunders . [4] Tec-Science. (2020, December 14). tec -science. https:// www.tec-science.com/thermodynamics/heat/specific-heat-capacity-of-selected-substances [ 5 ] Lancaster, P., Brettle , D., Carmichael, F., & Clerehugh , V. (2017). In-vitro thermal maps to characterize human dental enamel and dentin. Frontiers in Physiology, 8. https://doi.org/10.3389/fphys.2017.00461 [6] Niu , L., Dong, S., Kong, T., Wang, R., Zou, R., & Liu, Q. (2016). Heat Transfer Behavior across the Dentino -Enamel Junction in the Human Tooth. PLoS ONE, 11(9), e0158233. https:// doi.org/10.1371/journal.pone.0158233 [7] An, K. J. (2013). Assessment of the thermal conductivity of Yttria -Stabilized Zirconia coating. MATERIALS TRANSACTIONS, 55(1), 188–193. https:// doi.org/10.2320/matertrans.m2013172 [8] Limarga , A. M., Shian , S., Baram , M., & Clarke, D. R. (2012). Effect of high-temperature aging on the thermal conductivity of nanocrystalline tetragonal yttria -stabilized zirconia. Acta Materialia , 60 (15), 5417–5424. [9] Coefficient of thermal expansion in ceramics. Dimensional stability under heat. ( n.d. ). https://www.morgantechnicalceramics.com/en-gb/ceramics-101/thermal-properties-of-ceramics/coefficient-of-thermal-expansion / [10] Bona, A., Pecho , O., & Alessandretti , R. (2015). Zirconia as a dental biomaterial. Materials, 8(8), 4978–4991. https:// doi.org/10.3390/ma8084978 [11] Themes, U. (2015, January 1). 2. Properties of materials. Pocket Dentistry. https://pocketdentistry.com/2-properties-of-materials / [12] Cenci, M. S., Pereira-Cenci, T., Donassollo , T. A., Sommer , L., Strapasson , A., & Demarco, F. F. (2008). Influence of thermal stress on marginal integrity of restorative materials. Journal of Applied Oral Science, 16(2), 106–110. https:// doi.org/10.1590/s1678-77572008000200005 [13] Mainjot , A. K., Najjar , A., Jakubowicz -Kohen, B. D., & Sadoun , M. J. (2015). Influence of thermal expansion mismatch on residual stress profile in veneering ceramic layered on zirconia: Measurement by hole-drilling. Dental Materials, 31(9), 1142–1149. https:// doi.org/10.1016/j.dental.2015.06.017