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Endodontically treated teeth are though to be more susceptible to fracture as a result
of the loss of tooth vitality and tooth structure. This study was designed to compare
the contributions of endodontic and restorative procedures to the loss of strength
by using nondestructive occlusal loading on extracted intact, maxillary, second bicuspids.
An encapsulated strain gauge was bonded on enamel just above the cementoenamel junction
on both the buccal and lingual surfaces, and the teeth were mounted in nylon rings
leaving 2 mm of root surface exposed. Under load control, each tooth was loaded at
a rate of 37 N per s for 3 s and unloaded at the same rate in a closed loop servo-hydraulic
system to measure stiffness. A stress-strain curve was generated from each gauge prior
to alteration of the tooth and after each procedure performed on the tooth. Cuspal
stiffness, as a measure of tooth strength, was evaluated on one of two series of sequentially
performed procedures: 1. (a) unaltered tooth, (b) access preparation, (c) instrumentation,
(d) obturation, and (e) MOD cavity preparation; or 2. (a) unaltered tooth, (b) occlusal
cavity preparation, (c) two-surface cavity preparation, (d) MOD cavity preparation,
(e) access, (f) instrumentation, and (g) obturation. Results on 42 teeth indicate
that endodontic procedures have only a small effect on the tooth, reducing the relative
stiffness by 5%. This was less than that of an occlusal cavity preparation (20%).
The largest losses in stiffness were related to the loss of marginal ridge integrity.
MOD cavity preparation resulted in an average of a 63% loss in relative cuspal stiffness.
The results indicate that endodontic procedures do not weaken teeth with intact marginal
ridges.
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References
- Fracture susceptibility of endodontically treated teeth.J Endodon. 1980; 6: 560-565
- Intracoronal reinforcement and coronal coverage: a study of endodontically treated teeth.J Prosthet Dent. 1984; 51: 780-784
- Endodontically treated teeth as abutments.J Prosthet Dent. 1985; 53: 631-636
- Determination of the moisture content of vital and pulpless teeth.Oral Surg. 1972; 34: 661-670
- Root dentin hardness of endodontically treated teeth.J Endodon. 1981; 7: 421-422
- Punch shear testing of extracted vital and endodontically treated teeth.J Biomech. 1983; 16: 841-848
- Fracture strength of human teeth with cavity preparations.J Prosthet Dent. 1980; 43: 419-422
- Effect of prepared cavities on the strength of teeth.Oper Dent. 1981; 6: 2-5
- Resistance to cusp fracture in endodontically treated teeth.Dent Mater. 1987; 3: 232-235
- (Symposium sponsored by 3M, St. Paul, MN)Methods to improve fracture resistance of teeth.in: Vanherte G Smith DC International Symposium on posterior composite resin dental restorative materials. 1985: 443-450
- (Symposium sponsored by 3M, St. Paul, MN)Methods to improve fracture resistance of teeth.in: Vanherte G Smith DC International Symposium on posterior composite resin dental restorative materials. 1985: 433-441
- Biophysical stress analysis of restored teeth: experimental strain measurement.Dent Mater. 1988; 4: 41-48
- Cusp reinforcement with the acid-etch technique.J Dent Res. 1984; 63: 1075-1078
- Functional occlusal forces: an investigation by telemetry.J Prosthet Dent. 1978; 40: 326-333
- Restoration of endodontically treated posterior teeth.J Endodon. 1976; 2: 374-375
Article info
Footnotes
*This research was supported in part by a Grant-In-Aid of Research from the Endowment and Memorial Foundation of the American Association of Endodontists. The opinions, assertions, materials, and methodologies herein are private ones of the authors and are not to be construed as official or reflecting the views of the American Association of Endodontists or the Endowment and Memorial Foundation. This research was presented at the 45th Annual Meeting of the American Association of Endodontists, Anahelm, CA, where it won first place in the Graduate Student Presentations. This work was based on a thesis submitted to the Graduate School of the University of Minnesota in partial fulfillment of requirements for the MS degree. This study was also supported by Grant DE 08732 from the National Institute for Dental Research, Bethesda, MD.
**Composite resin restorative material and dentin bonding agent were supplied by Minnesota Mines, Metals, and Manufacturing (3M).
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Copyright
© 1989 The American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
