International Poster Journal of Dentistry and Oral Medicine



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Int Poster J Dent Oral Med 11 (2009), No. 4     15. Dec. 2009

Int Poster J Dent Oral Med 2009, Vol 11 No 4, Poster 467

Evaluation of modern post and core systems by testing the mechanical fatique resistance

Language: English

Assoc. Prof. Dr. Anca Mihaela Vitalariu,
University of Medicine and Pharmacy "Grigore T. Popa" Iasi, School of Dental Medicine, Romania
Assoc. Prof. Radu Comaneci,
Technical University "Gheorghe Asachi" Iasi, Faculty of Materials Science and Engineering, Romania

October 22-25th, 2008
The 19th International DAAAM Symposium
Trnava, Slovakia


Prosthetic treatment failures related to the mechanical deficiencies of post and core systems still represent a problem of clinical significance and justify the researches orientated through the increasing of their performances and clinical longevity. The fatigue resistance tests represent an essential research instrument because they simulate the repetitive cyclic pattern of the occlusal forces and replace the clinical tests that are time consuming and thus contribute to decrease of clinical evaluation costs and time.


The aim of the present study was to evaluate the fatigue resistance of the teeth restored with different posts (carbon fiber post, zirconium post, titanium post) when subjected to a cyclic loading test.

Material and Methods

We used forty human maxillary incisors having similar dimensions and without cracks, decay or abrasion. After anatomic crowns were removed, the teeth were endondontically treated and reconstructed with carbon fiber, ceramic and titanium posts. In the control group, no posts were used. The crown build-up was made with composite resin and covered with metal crowns. After that, teeth were mounted in acrylic resin blocks with a simulated periodontal ligament (fig. 1). The samples were divided into three experimental groups and one control group:
• group C - teeth restored with prefabricated carbon fibre reinforced posts;
• group Z - teeth restored with prefabricated zirconium posts;
• group T - teeth restored with prefabricated titanium posts;
• group M (control) - endodontically treated teeth with no posts.

Each test specimen was intermittently loaded to a maximum level of 25 daN at an angle of 45 degrees to the long axis of the tooth, at a frequency of 1.3 Hz until failure (fig. 2 and 3).

Fig. 1: The prepared sample Fig. 2: The sample mounted in the testing device
Fig. 3: The testing device and the data acquisition system


The testing device was stopped after 400 000 cyclic loads if no failure had occurred. Root fractures, post fractures and post and crown decementation were considered causes of failure.
The results obtained after 400.000 impacts are shown in the Table 1. Only one fracture was observed in the control group (teeth with no post) and three in carbon fiber group, while in zirconium and titanium groups were recorded six fractures in each group (fig. 4-7).
The survival rates of the groups were statistically compared with a Kaplan-Meier analysis (fig. 8).

Fig. 4: The fracture recorded in the control group (M) Fig. 5: The modes of failure recorded in group Z
Fig. 6: Fractures recorded in group C Fig. 7: Fractures recorded in group T
Fig. 8: Kaplan Meier curves of the experimental groups

The survival rates recorded in the experimental groups (C, Z and T) were lower than that of the control group. The differences between the experimental groups were significant, the teeth reconstructed with posts reinforced with carbon fibers had a higher survival rates than the teeth reconstructed with titanium and zirconium posts.

M (control)   Z (zirconia)   C (carbon)   T (titanium)  
92.794   26.171   251.123   18.763  
400.000   28.419   258.434   81.109  
> 400.000   149.762   262.257   90.981  
> 400.000   182.143   > 400.000   95.012  
> 400.000   241.112   > 400.000   101.448  
> 400.000   272.018   > 400.000   117.674  
> 400.000   > 400.000   > 400.000   > 400.000  
> 400.000   > 400.000   > 400.000   > 400.000  
> 400.000   > 400.000   > 400.000   > 400.000  
> 400.000   > 400.000   > 400.000   > 400.000  
Tab. 1: The results after 400.000 cyclic loads


Teeth reconstructed with fibre reinforced posts exhibit a higher fatigue resistance than teeth reconstructed with rigid posts (titanium or zirconium posts).
Fiber posts reduce the risk of root fracture and are the best choice in reconstruction of endodontically treated teeth. Knowing the advantages and disadvantages of different type of post, the dentist will be able to avoid a post that predispose to irreparable tooth fractures.


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  2. Heydecke G., Butz F., Hussein A., Strub J. R. Fracture strength after dynamic loading of endodontically treated teeth restored with different post-and-core systems. J Prosthet Dent 2002; 87: 438-445
  3. Hochman N., Zalkind M. New all-ceramic indirect post-and-core system. J Prosthet Dent 1999; 81: 625-629
  4. Maccari P. C., Conceicao E. N., Nunes M. F. Fracture resistance of endodontically treated teeth restored with three different prefabricated esthetic posts. J Esthet Restor Dent 2003;15 (1):25-30
  5. Rosentritt M., Furer C., Behr M., Lang R., Handel, G. Comparison of in vitro fracture strength of metallic and tooth-coloured posts and cores. J Oral Rehabil 2000;27(7):595-601

This Poster was submitted by Assoc. Prof. Dr. Anca Mihaela Vitalariu.

Correspondence address:
Assoc. Prof. Dr. Anca Mihaela Vitalariu
University of Medicine and Pharmacy "Grigore T. Popa" Iasi
School of Dental Medicine
16, University Street
700115 Iasi, Romania