Tags

Type your tag names separated by a space and hit enter

Effect of crown lengthening and ferrule placement on static load failure of cemented cast post-cores and crowns.
J Prosthet Dent. 2000 Aug; 84(2):169-79.JP

Abstract

STATEMENT OF PROBLEM

Restoration of mandibular second premolars with completely missing clinical crowns in the Kennedy Class I and II arches is costly and the risk of failure is high. Should the dentist choose crown-lengthening to allow the addition of a ferrule, despite incurring the disadvantage of an increased crown/root ratio?

PURPOSE

This in vitro study determined the combined effect of crown lengthening and placement of a ferrule on the failure resistance to static load of decoronated and restored mandibular second premolar analog teeth.

MATERIAL AND METHODS

An extracted mandibular second premolar of average dimensions was selected to form molded composite root analogs and metal crowns. Ten specimens prepared with no-ferrule root and negligible axial wall lengths and 10 specimens with ferrule root, apically repositioned finish lines, were made. Cast gold alloy post and cores and complete crowns were made and cemented. Each root was placed in bone-simulating resin located 3 mm from the finish line. Crown lengthened/ferrule and no-crown lengthened/no-ferrule groups were equally subdivided, whereby 5 crowns were compressively loaded on the buccal cusp tip and 5 were compressively loaded on the mesial marginal ridge. A testing machine applied force until failure occurred. Failure loads were examined with 2-way ANOVA. Significant differences were accepted at P </=.05.

RESULTS

Mean failure loads for the crown lengthened/ferrule and no-crown lengthened/no-ferrule groups were as follows: buccal load, 0.61 kN (SD +/- 0.11) and 0.83 kN (SD +/- 0.08); mesial load, 0.70 kN (SD +/- 0.08) and 1.00 kN (SD +/- 0.15), respectively. Crown lengthened/ferrule and no-crown lengthened/no-ferrule groups were significantly different (P <.001).

CONCLUSION

The combination of simulated surgical crown-lengthening and more apical crown margin placement to provide a 2-mm crown ferrule on a decoronated mandibular second premolar analog resulted in a reduction of static load failure for the restored analog tooth.

Authors+Show Affiliations

The Ohio State University College of Dentistry, Columbus, Ohio 43210, USA. gegauff.1@osu.edu

Pub Type(s)

Journal Article

Language

eng

PubMed ID

10946334

Citation

Gegauff, A G.. "Effect of Crown Lengthening and Ferrule Placement On Static Load Failure of Cemented Cast Post-cores and Crowns." The Journal of Prosthetic Dentistry, vol. 84, no. 2, 2000, pp. 169-79.
Gegauff AG. Effect of crown lengthening and ferrule placement on static load failure of cemented cast post-cores and crowns. J Prosthet Dent. 2000;84(2):169-79.
Gegauff, A. G. (2000). Effect of crown lengthening and ferrule placement on static load failure of cemented cast post-cores and crowns. The Journal of Prosthetic Dentistry, 84(2), 169-79.
Gegauff AG. Effect of Crown Lengthening and Ferrule Placement On Static Load Failure of Cemented Cast Post-cores and Crowns. J Prosthet Dent. 2000;84(2):169-79. PubMed PMID: 10946334.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effect of crown lengthening and ferrule placement on static load failure of cemented cast post-cores and crowns. A1 - Gegauff,A G, PY - 2000/8/18/pubmed PY - 2000/10/21/medline PY - 2000/8/18/entrez SP - 169 EP - 79 JF - The Journal of prosthetic dentistry JO - J Prosthet Dent VL - 84 IS - 2 N2 - STATEMENT OF PROBLEM: Restoration of mandibular second premolars with completely missing clinical crowns in the Kennedy Class I and II arches is costly and the risk of failure is high. Should the dentist choose crown-lengthening to allow the addition of a ferrule, despite incurring the disadvantage of an increased crown/root ratio? PURPOSE: This in vitro study determined the combined effect of crown lengthening and placement of a ferrule on the failure resistance to static load of decoronated and restored mandibular second premolar analog teeth. MATERIAL AND METHODS: An extracted mandibular second premolar of average dimensions was selected to form molded composite root analogs and metal crowns. Ten specimens prepared with no-ferrule root and negligible axial wall lengths and 10 specimens with ferrule root, apically repositioned finish lines, were made. Cast gold alloy post and cores and complete crowns were made and cemented. Each root was placed in bone-simulating resin located 3 mm from the finish line. Crown lengthened/ferrule and no-crown lengthened/no-ferrule groups were equally subdivided, whereby 5 crowns were compressively loaded on the buccal cusp tip and 5 were compressively loaded on the mesial marginal ridge. A testing machine applied force until failure occurred. Failure loads were examined with 2-way ANOVA. Significant differences were accepted at P </=.05. RESULTS: Mean failure loads for the crown lengthened/ferrule and no-crown lengthened/no-ferrule groups were as follows: buccal load, 0.61 kN (SD +/- 0.11) and 0.83 kN (SD +/- 0.08); mesial load, 0.70 kN (SD +/- 0.08) and 1.00 kN (SD +/- 0.15), respectively. Crown lengthened/ferrule and no-crown lengthened/no-ferrule groups were significantly different (P <.001). CONCLUSION: The combination of simulated surgical crown-lengthening and more apical crown margin placement to provide a 2-mm crown ferrule on a decoronated mandibular second premolar analog resulted in a reduction of static load failure for the restored analog tooth. SN - 0022-3913 UR - https://www.unboundmedicine.com/medline/citation/10946334/Effect_of_crown_lengthening_and_ferrule_placement_on_static_load_failure_of_cemented_cast_post_cores_and_crowns_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0022-3913(00)60140-3 DB - PRIME DP - Unbound Medicine ER -