JBiSE  Vol.6 No.4 , April 2013
Investigation of the torsional deformation of the complete upper denture: A pilot study
ABSTRACT

The aim of this research is to clarify whether the midline axis of the complete upper denture (CUD) is the axis of its torsion during loading, apart from the known bending deflection. Furthermore the present study is intended to estimate the influence of the anterior notches on the torsional deformation of the CUD. Using commercial edentulous molds and standardized procedures, six identical CUDs were fabricated with an initial fraenal notch of 5 mm. Two additional notch conditions were produced by deepening the notch to a total depth of 9 mm and by creating an incisal diastema of 7 mm. Five biaxial (also known as “fish bone”) strain gauges were cemented onto the palatal section of the dentures so that their middle axis coincided with the midline axis of the outer surface of the denture. For the denture specimen used in this study, the specific point of torsion was detected 2 cm from the point of contact of the two artificial central incisors. The presence of a deep fraenal notch and the combination of the deep fraenal notch with the presence of an incisal diastema increased the torsion of the CUD to a significant level (P = 0.006 and P = 0.05, respectively). It was shown that the midline can be the CUD’s axis of torsion. Biaxial strain gauges could be a reliable method of measuring the torsional deformation of the CUD.


Cite this paper
Prombonas, A. , Paralika, M. and Poulis, N. (2013) Investigation of the torsional deformation of the complete upper denture: A pilot study. Journal of Biomedical Science and Engineering, 6, 443-448. doi: 10.4236/jbise.2013.64055.
References
[1]   Beyli, M.S. and Fraunhofer, J.A. (1981) An analysis of causes of fracture of acrylic resin dentures. Journal of Prosthetic Dentistry, 46, 238-241. doi:10.1016/0022-3913(81)90206-7

[2]   Prombonas, A. and Vlissidis, D. (2002) Effects of the position of artificial teeth and load levels on the stress in the complete maxillary denture. Journal of Prosthetic Dentistry, 8, 415-422. doi:10.1067/mpr.2002.128174

[3]   Prombonas, A. and Vlissidis, D. (2009) Analysis of stresses in complete upper dentures with flat teeth at differing inclinations. Medical Engineering and Physics, 31, 314- 319. doi:10.1016/j.medengphy.2008.06.008

[4]   Prombonas, A., Vlissidis, D., Paralika, M.A. and Poulis, N.A. (2012) The stress state of the fraenal notch region in the complete upper dentures. Medical Engineering and Physics, 34, 1477-1482. doi:10.1016/j.medengphy.2012.02.009

[5]   Taylor, D. (2007) The theory of critical distances. A new perspective in fracture mechanics. Elsevier, London.

[6]   Smyd, E.S. (1961) The role of torque, torsion and bending in prosthetic failures. Journal of Prosthetic Dentistry, 11, 95-111. doi:10.1016/0022-3913(61)90116-0

[7]   Liu, Y. and Mahadevan, S. (2007) A unified multiaxial fatigue damage model for isotropic and anisotropic materials. International Journal of Fatigue, 29, 347-359. doi:10.1016/j.ijfatigue.2006.03.011

[8]   Wang, Y.Y. and Yao, W.X. (2006) A multiaxial fatigue criterion for various metallic materials under proportional and nonproportional loading. International Journal of Fatigue, 28, 401-408. doi:10.1016/j.ijfatigue.2005.07.007

[9]   Ahmadi, A. and Zenner, H. (2006) Lifetime simulation under multiaxial random loading with regard to the microcrack growth. International Journal of Fatigue, 28, 954-962. doi:10.1016/j.ijfatigue.2005.09.015

[10]   Meggiolaro, M.A., Castro, J.T.P. and Miranda, A.C.O. (2009) Evaluation of multiaxial stress-strain models and fatigue life prediction methods under proportional loading. Proceedings of the Second International Symposium on Solid Mechanics, Rio De Janeiro, 28-30 April 2009, 365-384.

[11]   Timoshenko, S.P. and Goodier, J.N. (1981) Theory of elasticity. McGraw-Hill, New York.

[12]   Cordey, J. (2000) Introduction: Basic concepts and definitions in mechanics. Injury, 31, 1-13. doi:10.1016/S0020-1383(00)80039-X

[13]   Ravi, N., Krishna, D.P., Manoj, S. and Chethan, H. (2010) A functional stress analysis in the maxillary complete denture influenced by the position of artificial teeth and load levels: An in-vitro study. Journal of Indian Prost- hodontic Society, 10, 219-225. doi:10.1007/s13191-011-0046-0

[14]   Zarb, G.A., Bolender, C.L. and Carlsson, G.E. (1997) Bouchers’s prosthetic treatment for edentulous patients. Mosby, St. Louis.

[15]   Muftah, M.H. and Haris, S.M. (2011) A strain gauge based system for measuring dynamic loading on a rotating shaft. International Journal of Mechanics, 5, 19-26.

[16]   Turvey, G.J. (1998) Torsion tests on pultruded GRP sheet. Composites Science and Technology, 58, 1343-1351. doi:10.1016/S0266-3538(98)00003-7

[17]   Dally, J. and Riley, W. (1991) Experimental stress analysis. College House Enterprises LLC, Knoxville.

[18]   Sorensen, R.E. and Ryge, G. (1962) Flow and recovery of denture plastics. Journal of Prosthetic Dentistry, 12, 1079- 1088. doi:10.1016/0022-3913(62)90163-4

[19]   Prombonas, A., Vlissidis, D. and Molyvdas, P. (1994) The effect of altering the vertical dimension of occlusion on biting force. Journal of Prosthetic Dentistry, 71, 139- 143. doi:10.1016/0022-3913(94)90021-3

 
 
Top