The mechanical properties of an orthodontic wire pultruded from S2-glass-reinforced polyethyleneterephthalate glycol (PETG) were measured using two experimental devices simulating clinical conditions. A comparison of moduli measured in the clinically relevant devices with those measured in a standard flexural test reveals that data obtained using small cross-section, short span length clinical specimens require corrections associated with clamping and shearing effects. The clamping effect dominates and is caused by the softening of the material near the clamps. The shear effect becomes important at high fibre volume fractions and small span/thickness ratios. With adoption of these corrections, good agreement between moduli calculated using rule of mixtures and those measured in clinical tests is achieved. The analytical base developed for prediction of the stiffness of the orthodontic wire for different span/thickness ratios improves the procedure for design of dental appliances.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
A. J. GOLDBERG and C. J. BURSTONE, J. Dent. Mater. in press (1992).
A. J. GOLDBERG, C. J. BURSTONE and H. A. KOENIG, J. Dent. Res. 62 (1983) 1016.
P. J. HENRY, B. M. BISHOP and R. M. PURT, Quint. Dent. Technol. 1990/1991 (1991) 110.
S. TIMOSHENKO, “Strength of materials”, vol. 1, 2nd Edn (van Nostrand, New York, 1940) p. 170.
Y. HADZIINIKOLAU PhD Thesis (1992).
D. A. ROLLINS, Research paper, Department of Orthodontics, University of Conn. Health Center, Farmington (1989).
Y. C. KU, “Deflections of beams for all spans and cross sections” (McGraw-Hill, New York, 1986) p. 136.
P. P. BENHAM and R. J. CRAWFORD, “Mechanics of engineering materials”, Ch. 7 (J. Wiley & Sons, New York, 1987) p. 172.
P. P. BENHAM and R. J. CRAWFORD, “Mechanics of engineering materials”, Ch. 7 (J. Wiley & Sons, New York, 1987) p. 216.
L. J. BROUTMAN and B. D. AGARWAL, “Analysis and performance of fiber composites” (J. Wiley & Sons, New York, 1980) p. 22.
A. KELLY and W. R. TYSON, J. Mech. Phys. Solids 13 (1965) 329.
A. T. DIBENEDETTO, Composite Sci. Technol. 42 (1991) 103.
F. L. SINGER, “Strength of materials”, Ch. 10 (Harper & Bros., New York, 1951) p. 329.
J. HALPIN and J. L. KARDOS, Polym. Eng. Sci. 16 (1976) 344.
J. G. WILLIAMS, “Stress analysis of polymers”, Ch. 4 (J. Wiley & Sons, New York, 1973) p. 113.
T. V. PARRY and A. S. WRONSKI, J. Mater. Sci. 16 (1981) 439.
L. J. BROUTMAN and B. D. AGARWAL, “Analysis and performance of fiber composites” (J. Wiley & Sons, New York, 1980) p. 58.
D. HULL, “An introduction to composite materials”, Ch. 7 (Cambridge University Press, Cambridge, 1981) p. 125.
S. TIMOSHENKO and J. N. GOODDIER, “Theory of elasticity”, 2nd Edn (McGraw-Hill, New York, 1951) p. 39.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Jancar, J., Dibenedetto, A.T., Hadziinikolau, Y. et al. Measurement of the elastic modulus of fibre-reinforced composites used as orthodontic wires. J Mater Sci: Mater Med 5, 214–218 (1994). https://doi.org/10.1007/BF00121091
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00121091