Abstract
Objective
There are no detailed reports of three-dimensional measurement of abutment teeth in mastication, because it is knotty to observe the rotation in chewing directly, and inexact to estimate indirectly. This work studies the three-dimensional stability of rigidly fixed bridge under the stresses of distributed loads and concentrated loads by optical method that gives the tip angle and rotation angle calculated directly based on measurement data.
Methods
The specimen, taken from a 25-year-old male, was a left mandible without the second premolars and the first molars. As abutments, first premolar and second molar have complete periodontium. The specimen was soaked in formaldehyde solution. The bridge was fixed between two abutment teeth (first premolars and second molars), and the mandible was cemented in a steel box. The load was increased from 0 kg to 23 kg. Laser holographic technique was used to measure the three-dimensional bit shift of the dens, both buccolingual bit shift and mesiodistal bit shift, and determine tip angle and rotation angle.
Results
The effects of stress distribution on the rigidly fixed bridge were evaluated, and stabilization of the bridge under the stresses of distributed loads and concentrated loads, respectively, were analyzed. The results showed that the tips of two abutments were very similar, and no distinct difference was observed between the distributed load and the concentrated load. However, the maximum rotation angle for the distributed load was two to four times as large as that for the concentrated load. In the experiment, the tip angle of the abutment teeth was no more than 0.65 degree, and the rotation angle was no more than 0.60 degree. All maximum angles occurred in the second molar.
Conclusion
The fixed bridge is considered to be safe. In addition, a method for measuring the rotation angle was provided effectively.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ante, I.H., 1926. The fundamental principles of abutments. Mich. State Dent. Soc. Bull., 8(14):232–257.
Craig, R.G., Peyton, F.A., 1967. Measurement of strains in fixed bridges with electronic strain gauges. J. Dent. Res., 46(3):615–619.
de Pauw, G., Dermaut, L., de Bruyn, H., 2003. The value of the centre of rotation in initial and longitudinal tooth and bone displacement. Eur. J. Orthodontics, 25(3):285–291. [doi:10.1093/ejo/25.3.285]
Farah, J.W., Craig, R.G., 1988. Finite element analysis of a mandibular model. J. Oral. Rehabil., 15(6):615–624.
Glikeman, I., Rober, F.M., Brion, M., Pameijer, J.H., 1970. Photoelastic analysis of internal stresses in the periodontium created by occlusal forces. J. Periodontol. Res., 41(1):30–35.
Hayashi, K., Araki, Y., Uechi, J., Ohno, H., Mizoguchi, I., 2002. A novel method for the three-dimensional (3-D) analysis of orthodontic tooth movement-calculation of rotation about and translation along the finite helical axis. J. Biomech., 35(1):45–51. [doi:10.1016/S0021-9290(01)00166-X]
Liu, D.X., Wang, C.L., Zhang, X.Y., Zheng, X.Z., 2004. FEM study on displacement, position of rotation center and distribution of PDL under various loading force systems. West China J. Stomatol., 22(3):192–195 (in Chinese).
Young, J.M., Altschuler, B.R., 1977. Laser holography in dentistry. The Journal of Prosthetic Dentistry, 38(2):216–220. [doi:10.1016/0022-3913(77)90289-X]
Zhu, X.T., Bai, X., Zhou, X.G., 1985. Laser holographic analysis on force distribution of rigid and nonrigid fixed bridges. Chin. J. Biomed. Eng., 4(1):58–62 (in Chinese).
Author information
Authors and Affiliations
Corresponding author
Additional information
Project supported by the Science Research Foundation of Ministry of Health of China (No. WKJ2006-2-003), the Department of Education of Zhejiang Province (No. 20010505) and the Science and Technology Department of Zhejiang Province (No. 2003C30044), China
Rights and permissions
About this article
Cite this article
Zhang, Yz., Zhou, Yc., Liu, L. et al. Stabilization of an abutment under a rigidly fixed bridge by holographical-speckle interferometry. J. Zhejiang Univ. - Sci. B 8, 416–421 (2007). https://doi.org/10.1631/jzus.2007.B0416
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1631/jzus.2007.B0416