Janice A Townsend1, Patrick Knoell2, Qingzhao Yu3, Jian-Feng Zhang4, Yapin Wang4, Han Zhu5, Sean Beattie6, Xiaoming Xu7. 1. Department of Pediatric Dentistry, School of Dentistry, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, La., USA. jtown2@lsuhsc.edu. 2. Private practice, Lawrenceburg, Tenn., USA. 3. School of Public Health, Louisiana State University Health Sciences Center, New Orleans, La., USA. 4. School of Dentistry, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, La., USA. 5. Biostatistics Program, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, La., USA. 6. Private practice, London, Ontario, Canada. 7. Department of Comprehensive Dentistry and Biomaterials, School of Dentistry, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, La., USA.
Abstract
PURPOSE: The purpose of this study was to measure the fracture resistance of primary mandibular first molar zirconia crowns from three different manufacturers-EZ Pedo (EZP), NuSmile (NSZ), and Kinder Krowns (KK)-and compare it with the thickness of the zirconia crowns and the measured fracture resistance of preveneered stainless steel crowns (SSCs). METHODS: The thickness of 20 zirconia crowns from three manufacturers were measured. The mean force required to fracture the crowns was determined. Preveneered NuSmile (NSW) SSCs were tested as a control. RESULTS: EZP crowns were significantly thicker in three of the six measured locations. The force required to fracture the EZP crown was significantly higher than that required for NSZ and KK. There was a positive correlation between fracture resistance and crown thickness in the mesial, distal, mesioocclusal, and distoocclusal dimensions. None of the zirconia crowns proved to be as resistant to fracture as the preveneered SSCs. CONCLUSIONS: Statistically significant differences were found among the forces required to fracture zirconia crowns by three different manufacturers. The increase in force correlated with crown thickness. The forces required to fracture the preveneered stainless steel crowns were greater than the forces required to fracture all manufacturers' zirconia crowns.
PURPOSE: The purpose of this study was to measure the fracture resistance of primary mandibular first molar zirconia crowns from three different manufacturers-EZ Pedo (EZP), NuSmile (NSZ), and Kinder Krowns (KK)-and compare it with the thickness of the zirconia crowns and the measured fracture resistance of preveneered stainless steel crowns (SSCs). METHODS: The thickness of 20 zirconia crowns from three manufacturers were measured. The mean force required to fracture the crowns was determined. Preveneered NuSmile (NSW) SSCs were tested as a control. RESULTS: EZP crowns were significantly thicker in three of the six measured locations. The force required to fracture the EZP crown was significantly higher than that required for NSZ and KK. There was a positive correlation between fracture resistance and crown thickness in the mesial, distal, mesioocclusal, and distoocclusal dimensions. None of the zirconia crowns proved to be as resistant to fracture as the preveneered SSCs. CONCLUSIONS: Statistically significant differences were found among the forces required to fracture zirconia crowns by three different manufacturers. The increase in force correlated with crown thickness. The forces required to fracture the preveneered stainless steel crowns were greater than the forces required to fracture all manufacturers' zirconia crowns.
Authors: Mebin George Mathew; Korishettar Basavaraj Roopa; Ashu Jagdish Soni; Md Muzammil Khan; Afreen Kauser Journal: J Family Med Prim Care Date: 2020-03-26
Authors: Sharat Chandra Pani; Abdulrahman Al Saffan; Sultan AlHobail; Fares Bin Salem; AlBara AlFuraih; Mohammad AlTamimi Journal: Int J Dent Date: 2016-06-29