Experimental and Numerical Comparison of Stresses Level between Titanium and Novel Composite Single Tooth Implant

Transcription

1 International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:06 84 Experimental and Numerical Comparison of Stresses Level between Titanium and Novel Composite Single Tooth Implant Adawiya Ali Hamzah M. Sc. (Applied Mechanics) Baghdad University/Engineering College/Mechanical Department Abstract-- This work represents a comparison study between using the convenient titanium alloy used to manufacturing tooth implant with a novel material (eggshell powder with polyester). Total tooth implant model was analyzed through using finite elements analyzer ANSYS software (workbench) V.14 and with applying load and boundary condition it is easy to get all important design specification. Three percentages of volume fractions (represents percentage of eggshell powder to polyester) for the novel material (eggshell powder with polyester) had been studied where it was 0.3, 0.4, and 0.5 with mechanical properties measured by experimental tests. All the materials are assumed to be homogenous isotropic and experimental tests had been done for the novel material (eggshell with polyester) with different values of volume fraction 0.3, 0.4, and 0.5 in order to specify its mechanical properties. Results show high degree of agreement in stresses level between the convenient and the new material (at 0.5 volume fraction) for effective stress, Maximum principle stress (at 0.4 volume fraction) and equivalent elastic strain (at 0.3 volume fraction). Index Term-- Tooth implant, ANSYS software, Finite elements, novel material, Volume fraction, Effective stress. 1. INTRODUCTION Tooth loss, particularly loss of posterior teeth, leads to insufficient masticatory performance [1]. Masticatory represents an important factor for general health of human and where it can directly affect the nutritional status, life's quality, and overall health, specifically in the elderly [2, 3]. Several prosthetic treatments are used to replace the missing dentition. Many techniques for replacing the missing or posterior teeth one of these is implant-supported fixed dental prosthesis (FDP) [4]. Loads type and direction of [5], the quality and quantity of the supporting bone,[6] dental implant, and prosthetic material types [7], represent the most important factors which can affect directly on the sseointegration and prognosis of implant-supported [8,9]. The influences of Prosthetic material type on stress distribution in dental implants and consequently effect on morphology of bone, may lead to the Osseo integration loss [10]. Currently, porcelain is according to new tests presents an accepted level of fracture resistance, aesthetics and fit, so that most clinicians recommend it [11, 12]. But the work is in progress in order to produce a novel material which can be used for manufacturing tooth implant. Due to significant role of prosthetic material with different physical and mechanical properties, it is necessary to show its effect and produced pattern of stress through mastication. Hence, the present work analyzes stress distribution tooth implant when occlusal load was applied with different framework materials. 2. FINITE ELEMENTS MODEL In the present study, a three-dimensional (3D) finite elements model of tooth implant was modeled and used with ANSYS V.14 software, where the total implant was modeled with its parts as shown in figure.1 based on Wheeler s dental anatomy textbook [13]. SOLID 45 element type used in order to calculate the stress distribution. Based on this FEA modeling, all stress components can be obtained. In particular, the Von Mises stress was the major interest. 3. MATERIALS PROPERTIES As mentioned previously two types of materials were used the first one is the titanium alloy and second one is a novel material of eggshell powder with different values of volume fraction (0.3, 0.4, and 0.5) where its mechanical properties had been calculated experimentally at room temperature (25C )where specimens cutting to get the final dimensions flat specimens according to ASTM D638 [14], specimens were tested by using the universal instruments for flexural and tensile tests in the Laboratories of materials as shown in figure 2, also to find the Young's modulus, maximum bending stress and Poisson's ratio, according to ASTM F1717 [15], were tested by torsion test device as shown in figure 3 to find modulus of rigidity and maximum shear stress. In table 1 the mechanical properties had been shown for these materials. All materials were assumed to be isotropic, homogeneous, time-independent, and linear elastic.

2 International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No: LOADING AND BOUNDARY CONDITION To simulate the model during loading case for example while eating the load was considered to be static load of N applied normally on the upper surface of the tooth implant without any horizontal or torsional load. To apply the boundary condition, all nodes of root region is considered to firmly fixed in all direction [16]. Load and boundary condition is shown in figure.4. After finishing the experimental results for each materials test, Von Mises equation is used to calculate maximum stress, and comparing these results with the numerical results of maximum stress. 5. RESULTS The stress distribution for tooth implant can be considered as an important factor for designing it or any mechanical system so in this study the stress distribution was used to investigate the strength of implant under special load case. In figure 5 the effective stress distribution was shown for titanium alloy implant where the left shape shows the stress distribution contour. The same contours were shown in figure 6 but with implant made from eggshell powder with polyester (at 0.5 volume fraction). Results in these two implants shows that effective stress of eggshell powder with polyester (at 0.4 volume fraction) implant is very near to the effective stress of titanium alloy implant, and equivalent elastic stress results of eggshell powder with polyester ( 0.3 volume fraction) is similar to the titanium alloy results. Similarly for maximum principle stress and equivalent elastic strain as shown in figures 7 & 8 respectively. 6. DISCUSSION AND CONCLUSIONS FEA modeling was presented in this work for modeling tooth implant under static load focused on implant but in different side of view where to avoid all the problems that may appear starting from design process until the manufacturing, producing, cost and so on. So that seeking for an alternative biomedical materials can solve these problems. A comparison had been done between the results (stresses) of titanium alloy and eggshell powder with polyester, it was found that volume fraction of 0.5 leads to converge results for effective stress but at 0.4 and 0.3 leads to converge the results for maximum principle stress and equivalent elastic strain respectively. In static analysis the stress distribution along a tooth implant is presented and from the contours of stress the position of maximum stress concentration had been shown where the point of junction between the neck end and head had the maximum value of stress due to sudden change in cross sectional area of implant where that is noticed for all studied sizes and for all materials types, so it is important to take into account this position during the designing in order to reduce the concentration of stress. As mentioned previously there is very small difference in overall results while comparing between the two materials used. This work may open the door to introduce new materials types that could be used to manufacture a novel tooth implant made from eggshell powder with polyester which is cheaper than titanium. This study it is possible to introduce a new technic can improve the strength of dental implants in general by changing manufacturing material. Fig. 1. 3D Model of tooth implant.

3 International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:06 86 a- Tensile test b- Flexural test Fig. 2. Tensile and flexural static tests device stress [17]. Fig. 4. Boundary conditions.

4 International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:06 87 Fig. 3. Torsion static stress test device [17]. Fig. 5. Effective stress of titanium tooth implant.

5 International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:06 88 Fig. 6. Effective stress of eggshell powder with eggshell polyester (at 0.5 volume fraction) tooth implant. Titanium alloy implant. Eggshell powder with polyster (at 0.4 volume fraction) tooth implant. Fig. 7. Maximum principle stress.

6 International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:06 89 Titanium alloy implant. Eggshell powder with polyster (at 0.3 volume fraction) tooth implant. Fig. 8. Equivalent elastic stress. Material Young's modulus [Gpa] Table I Material properties at room temperature (25 c ). Poisson's ratio Max. bending stress[mpa] Modulus rigidity[gpa] Titanium alloy Eggshell powder with polyester (at 0.3 volume fraction) Eggshell powder with polyester (at 0.4 volume fraction) Eggshell powder with polyester (at 0.5 volume fraction) of Maximum shear stress[mpa] REFERENCES [1] Kh. S, K. AH, Feizi A, S. O, Adibi P. "Epidemiology and risk factors of tooth loss among Iranian adults: Findings from a large community-based study". Biomed Res Int 2013;2013: [2] Ma.s W, Steele JG, Sh. A, Walls AW. "The relationship between dental status, food selection, nutrient intake, nutritional status, and body mass index in older people". Cad Saude Publica 2003;19: [3] Ka. S, Savabi G, Kha.S, Savabi O, Esmail. A, Keshteli AH, et al. "Association between food intake and oral health in elderly: SEPAHAN systematic review no. 8". Dent Res J (Isfahan) 2011;8:S [4] M. CE. "Dental implant prosthetics". St louis, Missouri: Elsevier Mosby; p [5] Holm. EP, S. RJ, Kilgren LM, Mante F." Evaluating parameters of osseointegrated dental implants using finite element analysis a two-dimensional comparative study examining the effects of implant diameter, implant shape, and load direction." J Oral Implant ol 1998;24:80-8. [6] F. J, G. T, Proff P." Bone quality, quantity and metabolism in terms of dental implantation. Biomed Tech " 2008;53: [7] De A.F, M.A, Vitalone LM, Carl. F, Vadini M, Paolantonio M, et al. "Bond strength evaluation of three self adhesive luting systems used for cementing composite and porcelain". Oper Dent 2011;36: [8] Ciftci Y,.S. "Stress distribution on the metal framework of the implant-supported fixed prosthesis using different veneering materials". Int J Prosthodont 2001;14: [9] D. Jager N, de K. M, van der JM. "The influence of different core material on the FEA-determined stress distribution in dental crowns". Dent Mater 2006;22: [10] O B. WJ. "Dental materials and their selection: Quintessence Publishing "Co.; 4th edtion. 2008; Chapter 9, p [11] Co. HJ, S.WJ, P. IJ. "Current ceramic materials and systems with clinical recommendations: A systematic review". J Pr. Dent 2007;98: [12] D. Bona A, K. JR." ". J Am Dent Assoc 2008;139 Suppl:8-13S.

7 International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:06 90 [13] SJ, Ash M." Dental anatomy", Physiology and Occlusion 9th edition. St Louis, Missouri 63148: Elsevier: Saunders 2010, 151-5, [14] American Society for Testing and Materials Information, Handing Series, "Standard Test Method for Tensile Properties", [15] ASTM standard, Fatigue Torsion F1717, [16] İ. H, Akça K. "Comparative evaluation of the effect of diameter, length and number of implants supporting three unit fixed partial prostheses on stress distribution in the bone". [17] Dr. Majid H. Faidh-Allah, Mahmood Wael Saeed, Adawiya A. Hamzah. "Experimental and Numerical Study the Effect of Materials Changing on Behavior of Dental Bur (Straight Fissure) under Static Stress Analysis. Innovative Systems Design and Engineering", Vol.6, No.2, 2015.