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Author Spotlight: Establishing an Accurate Microhardness Testing Protocol for Craniofacial Tissues
Published on: April 26, 2024
Influence of different irrigation protocols on microhardness and flexural strength values of young and aged crown
Nurab Deniz Pedersen1, Emel Uzunoglu-Özyürek1, Hatice Dogan Buzoglu1
1Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
Objective:
To investigate the effect of different irrigation protocols on microhardness (MH) and flexural strength (FS) values of young and aged crown dentin.
Background:
In addition to ageing, root canal irrigation might also affect the mechanical properties of coronal dentin walls.
Materials And Methods:
One hundred and twenty dentin bars (2 mm × 2 mm × 8 mm) were obtained from the crowns of extracted, non-caries, human molars of young and older patients (n = 60 bars; average patient ages: 16.7 and 65.4, respectively). Subgroups were formed as follows: 2.5%NaOCl(sodium hypochlorite)+5%EDTA(ethylenediaminetetraacetic acid), 2.5%NaOCl + 15%EDTA, 2.5%NaOCl, 5%EDTA, 15%EDTA and Saline. NaOCl and saline were used for 20 minutes and EDTA solutions for 1 minute. MH values of each sample were measured before and after the irrigation protocols. The same samples were also submitted for FS analysis. The data were statistically analysed.
Results:
Young samples had lower MH values at pre- and post-treatment compared to aged samples (P < .05). A significant decrease was observed in MH values of aged samples exposed to 2.5%NaOCl and both NaOCl + EDTA combinations (P < .05). FS values of the young saline-treated group were statistically higher than aged ones (P < .05). Both NaOCl + EDTA combinations caused a significant decrease in FS values of young samples compared to saline (P < .05).
Conclusion:
Ageing has a significant effect on the MH and FS values of crown dentin samples. 5% EDTA solutions revealed similar results to 15%EDTA regarding MH and FS values of crown dentin in both age groups. The NaOCl + EDTA combination had a prominent effect than EDTA alone, on MH values of young-, and FS values of aged dentin samples.
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