PMID- 38418282
OWN - NLM
STAT- MEDLINE
DCOM- 20240415
LR  - 20240415
IS  - 1879-0097 (Electronic)
IS  - 0109-5641 (Linking)
VI  - 40
IP  - 4
DP  - 2024 Apr
TI  - Comparison of subcritical growth parameters of a Y-TZP obtained via cyclic or 
      dynamic fatigue tests.
PG  - 747-755
LID - S0109-5641(24)00024-1 [pii]
LID - 10.1016/j.dental.2024.02.005 [doi]
AB  - OBJECTIVE: The objective of this study was to 1) compare the stress corrosion 
      coefficient (n) of a Y-TZP obtained by two fatigue tests: cyclic and dynamic and 
      2) evaluate the effect of frequency in the characteristic lifetime and the 
      existence of interaction between the cyclic fatigue and slow crack growth. 
      METHODS: A total of 145 Y-TZP specimens were produced in accordance with the 
      manufacturer's instructions. These specimens, measuring 4.0 x 3.0 x 25.0 mm, were 
      used for dynamic (n = 70) and cyclic fatigue tests (n = 75). The specimens were 
      obtained from CAD/CAM blocks, sectioned, and sintered in a furnace at 1530  degrees C 
      with a heating rate of 25  degrees C/min. They were tested in their "as-sintered" form 
      without any additional surface treatment. The fatigue tests were conducted using 
      a four-point bending to obtain the slow crack growth parameters (n). The cyclic 
      fatigue test was also conducted in two frequencies (2 and 10 Hz), using stress 
      levels between 350 and 600 MPa. Data from these tests were analyzed using ASTM C 
      1368-00 formulas and Weibull statistics. Scanning electron microscope (SEM) was 
      used for fracture surface analysis to identify the origin of the fracture. 
      Critical defect size was measured and used, along with flexural strength values, 
      to estimate fracture toughness. Dynamic fatigue test data were used to obtain 
      subcritical crack growth (SCG) parameters and perform Weibull statistical 
      analysis. The cyclic fatigue data were used in the General Log-linear Model 
      equation using the ALTA PRO software. Data were analyzed using one-way ANOVA 
      followed by Tukey post-hoc tests and Student's t-test at a significance level of 
      p </= 0.05. RESULTS: In the dynamic fatigue test, the values obtained for sigma(fo) and 
      n were 667 and 54, respectively. This parameter indicates how the strength of the 
      material diminishes over time due to internal cracks. The Weibull parameters 
      obtained from the same test results were m = 7.9, sigma(0) = 968, 9 and sigma(5%) = 767, 
      which indicates the reliability of the material. The Weibull parameters obtained 
      by cyclic fatigue were statistically similar for the two frequencies used, the 
      m* was 0.17 (2 Hz) and 0.21 (10 Hz); characteristic lifetimes (eta) were 
      1.93 x 10(6) and 40,768, respectively. The n values obtained by cyclic fatigue 
      were 48 and 40 at frequencies of 2 and 10 Hz, respectively. There was no effect 
      of the frequency, the stress level or the interaction of the two in the Y-TZP 
      lifetime, when analysed by General Log Linear Model. SIGNIFICANCE: the n values 
      obtained by cyclic and dynamic fatigue tests showed no statistically significant 
      difference and the effect of frequency in the characteristic lifetime and the 
      existence of interaction between the cyclic fatigue and subcritical growth were 
      not observed in the tested specimens.
CI  - Copyright (c) 2024 Elsevier Inc. All rights reserved.
FAU - Fukushima, Karen Akemi
AU  - Fukushima KA
AD  - Department of Biomaterials and Oral Biology, School of Dentistry, University of 
      Sao Paulo, Av. Prof. Lineu Prestes, 2227, Cidade Universitaria, Sao Paulo, SP 
      05508-000, Brazil.
FAU - Alhotan, Abdulaziz
AU  - Alhotan A
AD  - Dental Health Department, College of Applied Medical Sciences, King Saud 
      University, Riyadh 11454, Saudi Arabia.
FAU - Riman, Sahar Ganz
AU  - Riman SG
AD  - Department of Biomaterials and Oral Biology, School of Dentistry, University of 
      Sao Paulo, Av. Prof. Lineu Prestes, 2227, Cidade Universitaria, Sao Paulo, SP 
      05508-000, Brazil.
FAU - Joshi, Gaurav
AU  - Joshi G
AD  - Department of Biomedical Materials Science, University of Mississippi Medical 
      Center, 2500 North State Street, Room D528, Jackson, MS 39216-4505, USA.
FAU - Duan, Yuanyuan
AU  - Duan Y
AD  - Department of Biomedical Materials Science, University of Mississippi Medical 
      Center, 2500 North State Street, Room D528, Jackson, MS 39216-4505, USA.
FAU - Griggs, Jason A
AU  - Griggs JA
AD  - Department of Biomedical Materials Science, University of Mississippi Medical 
      Center, 2500 North State Street, Room D528, Jackson, MS 39216-4505, USA.
FAU - Cesar, Paulo Francisco
AU  - Cesar PF
AD  - Department of Biomaterials and Oral Biology, School of Dentistry, University of 
      Sao Paulo, Av. Prof. Lineu Prestes, 2227, Cidade Universitaria, Sao Paulo, SP 
      05508-000, Brazil. Electronic address: paulofc@usp.br.
LA  - eng
PT  - Journal Article
DEP - 20240227
PL  - England
TA  - Dent Mater
JT  - Dental materials : official publication of the Academy of Dental Materials
JID - 8508040
RN  - 12001-21-7 (Dental Porcelain)
RN  - C6V6S92N3C (Zirconium)
RN  - 58784XQC3Y (Yttrium)
SB  - IM
MH  - *Dental Porcelain
MH  - Reproducibility of Results
MH  - Materials Testing
MH  - Dental Stress Analysis
MH  - *Flexural Strength
MH  - Zirconium
MH  - Surface Properties
MH  - Ceramics
MH  - Yttrium
OTO - NOTNLM
OT  - Chipping
OT  - Dental ceramics
OT  - Fatigue
OT  - Flexural strength
OT  - Weibull
EDAT- 2024/02/29 00:43
MHDA- 2024/04/15 06:42
CRDT- 2024/02/28 21:53
PHST- 2023/05/15 00:00 [received]
PHST- 2024/01/30 00:00 [revised]
PHST- 2024/02/09 00:00 [accepted]
PHST- 2024/04/15 06:42 [medline]
PHST- 2024/02/29 00:43 [pubmed]
PHST- 2024/02/28 21:53 [entrez]
AID - S0109-5641(24)00024-1 [pii]
AID - 10.1016/j.dental.2024.02.005 [doi]
PST - ppublish
SO  - Dent Mater. 2024 Apr;40(4):747-755. doi: 10.1016/j.dental.2024.02.005. Epub 2024 
      Feb 27.