Tags

Type your tag names separated by a space and hit enter

Influence of cyclic loading and luting agents on the fracture load of two all-ceramic crown systems.
J Prosthet Dent. 2004 Dec; 92(6):551-6.JP

Abstract

STATEMENT OF PROBLEM

Inherent mechanical properties, fabrication techniques, luting agents, and intraoral conditions are primary factors attributing to longevity of all-ceramic crowns. Before doing time-consuming and costly clinical studies, preclinical in vitro studies should be conducted to evaluate the durability of these crowns. Purpose This study investigated the influence of different luting agents and cyclic loading under wet conditions on the fracture load of CAD-CAM and pressable all-ceramic crowns.

MATERIAL AND METHODS

Ninety-six human premolars were prepared for all-ceramic crowns with the following preparation criteria: 6-degree axial taper, 1.5-mm shoulder finish line placed 0.5 mm occlusal to the CEJ, 2-mm occlusal reduction, and occluso-gingival height of 5 mm. Sixteen unprepared premolars served as controls. Forty-eight crowns were laboratory fabricated from a lithium disilicate glass-ceramic (IPS-Empress 2), while 48 CAD-CAM crowns were directly fabricated using a leucite-reinforced glass-ceramic (ProCAD) and the Cerec 3 CAD-CAM system. Three luting agents (Panavia F, Superbond C&B and ProTec CEM) were used for cementation (n = 16). After 1 week storage in water, half of the specimens of each subgroup (n = 8) were cyclically loaded and thermal cycled under wet conditions for 600,000 masticatory cycles and 3500 thermal cycles (58 degrees C/4 degrees C; dwell time 60 seconds) in a masticatory simulator. All specimens were loaded in a universal testing machine with the compressive load (N) applied along the long axis of the specimen at a crosshead speed of 1 mm/min until fracture. Fracture load was recorded for each specimen. The Kruskal-Wallis test was used first to detect overall significance, followed by Mann-Whitney U tests to identify which pairs of groups had significant differences (P =.05).

RESULTS

Cyclic loading significantly decreased the median fracture load of ProCAD crowns luted using Superbond from 987.2 to 786.0 N (P =.014) and those luted using ProTec CEM from 914.4 to 630.7 N (P =.007). Also, the median fracture load of Empress 2 crowns luted using ProTec CEM decreased significantly from 977.3 to 622.9 N (P =.013). However, cyclic loading did not decrease the median fracture load of crowns luted using Panavia F, Empress 2 (P =.431) and ProCAD (P =.128). With the same loading conditions and luting agents, there were no significant differences in the fracture loads of ProCAD and Empress 2 crowns (P >.05).

CONCLUSIONS

Cyclic loading reduced the fracture load of ProCAD crowns luted with Superbond C&B and ProTec CEM and of Empress 2 crowns luted with ProTec CEM.

Authors+Show Affiliations

Department of Conservative Dentistry and Fixed Prosthodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt. aattia@mans.edu.egNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15583561

Citation

Attia, Ahmed, and Matthias Kern. "Influence of Cyclic Loading and Luting Agents On the Fracture Load of Two All-ceramic Crown Systems." The Journal of Prosthetic Dentistry, vol. 92, no. 6, 2004, pp. 551-6.
Attia A, Kern M. Influence of cyclic loading and luting agents on the fracture load of two all-ceramic crown systems. J Prosthet Dent. 2004;92(6):551-6.
Attia, A., & Kern, M. (2004). Influence of cyclic loading and luting agents on the fracture load of two all-ceramic crown systems. The Journal of Prosthetic Dentistry, 92(6), 551-6.
Attia A, Kern M. Influence of Cyclic Loading and Luting Agents On the Fracture Load of Two All-ceramic Crown Systems. J Prosthet Dent. 2004;92(6):551-6. PubMed PMID: 15583561.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Influence of cyclic loading and luting agents on the fracture load of two all-ceramic crown systems. AU - Attia,Ahmed, AU - Kern,Matthias, PY - 2004/12/8/pubmed PY - 2005/2/23/medline PY - 2004/12/8/entrez SP - 551 EP - 6 JF - The Journal of prosthetic dentistry JO - J Prosthet Dent VL - 92 IS - 6 N2 - STATEMENT OF PROBLEM: Inherent mechanical properties, fabrication techniques, luting agents, and intraoral conditions are primary factors attributing to longevity of all-ceramic crowns. Before doing time-consuming and costly clinical studies, preclinical in vitro studies should be conducted to evaluate the durability of these crowns. Purpose This study investigated the influence of different luting agents and cyclic loading under wet conditions on the fracture load of CAD-CAM and pressable all-ceramic crowns. MATERIAL AND METHODS: Ninety-six human premolars were prepared for all-ceramic crowns with the following preparation criteria: 6-degree axial taper, 1.5-mm shoulder finish line placed 0.5 mm occlusal to the CEJ, 2-mm occlusal reduction, and occluso-gingival height of 5 mm. Sixteen unprepared premolars served as controls. Forty-eight crowns were laboratory fabricated from a lithium disilicate glass-ceramic (IPS-Empress 2), while 48 CAD-CAM crowns were directly fabricated using a leucite-reinforced glass-ceramic (ProCAD) and the Cerec 3 CAD-CAM system. Three luting agents (Panavia F, Superbond C&B and ProTec CEM) were used for cementation (n = 16). After 1 week storage in water, half of the specimens of each subgroup (n = 8) were cyclically loaded and thermal cycled under wet conditions for 600,000 masticatory cycles and 3500 thermal cycles (58 degrees C/4 degrees C; dwell time 60 seconds) in a masticatory simulator. All specimens were loaded in a universal testing machine with the compressive load (N) applied along the long axis of the specimen at a crosshead speed of 1 mm/min until fracture. Fracture load was recorded for each specimen. The Kruskal-Wallis test was used first to detect overall significance, followed by Mann-Whitney U tests to identify which pairs of groups had significant differences (P =.05). RESULTS: Cyclic loading significantly decreased the median fracture load of ProCAD crowns luted using Superbond from 987.2 to 786.0 N (P =.014) and those luted using ProTec CEM from 914.4 to 630.7 N (P =.007). Also, the median fracture load of Empress 2 crowns luted using ProTec CEM decreased significantly from 977.3 to 622.9 N (P =.013). However, cyclic loading did not decrease the median fracture load of crowns luted using Panavia F, Empress 2 (P =.431) and ProCAD (P =.128). With the same loading conditions and luting agents, there were no significant differences in the fracture loads of ProCAD and Empress 2 crowns (P >.05). CONCLUSIONS: Cyclic loading reduced the fracture load of ProCAD crowns luted with Superbond C&B and ProTec CEM and of Empress 2 crowns luted with ProTec CEM. SN - 0022-3913 UR - https://www.unboundmedicine.com/medline/citation/15583561/Influence_of_cyclic_loading_and_luting_agents_on_the_fracture_load_of_two_all_ceramic_crown_systems_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0022391304005852 DB - PRIME DP - Unbound Medicine ER -