Statement Of Problem: Fracture of veneering ceramics in zirconia-based restorations has frequently been reported. Investigation of the fracture mode of implant-supported ceramic restorations by using clinically relevant laboratory protocols is needed.
Purpose: This study compared the mode of fracture and number of cyclic loads until veneering fracture when ceramic and metal ceramic restorations with different veneering ceramics were supported by implants.
Material And Methods: Thirty-two implant-supported single-tooth restorations were fabricated. The test group was composed of 16 ceramic restorations of zirconia abutment-retained crowns with zirconia copings veneered with glass-ceramics (n=8) and feldspathic ceramics (n=8). The control group was composed of 16 metal ceramic restorations of titanium abutment-retained crowns with gold alloy copings veneered with glass (n=8) and feldspathic ceramics (n=8). The palatal surfaces of the crowns were exposed to cyclic loading of 800 N with a frequency of 2 Hz, which continued to 4.2 million cycles or until fracture of the copings, abutments, or implants. The number of cycles and the fracture modes were recorded. The fracture modes were analyzed by descriptive analysis and the Mann-Whitney test (α=.05). The differences in loading cycles until veneering fracture were estimated with the Cox proportional hazards analysis.
Results: Veneering fracture was the most frequently observed fracture mode. The severity of fractures was significantly more in ceramic restorations than in metal ceramic restorations. Significantly more loading cycles until veneering fracture were estimated with metal ceramic restorations veneered with glass-ceramics than with other restorations.
Conclusions: The metal ceramic restorations demonstrated fewer and less severe fractures and resisted more cyclic loads than the ceramic restorations, particularly when the metal ceramic crowns were veneered with glass-ceramics.
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http://dx.doi.org/10.1016/S0022-3913(12)60110-3 | DOI Listing |
Materials (Basel)
January 2025
Division of Biomaterials, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL 35209, USA.
Two 3D-printed crown materials (Crown and Ceramic Crown) were examined to determine the best surface treatment and primers for bonding. Discs of the two materials were printed and mounted with their "intaglio" surfaces untouched. Half the specimens from each group were sandblasted with 50 µm alumina.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100101, China.
To assess the biomechanical behaviors of endodontically treated molars (ETMs) restored with endocrowns composed of different materials, forty mandibular molars were assigned to five groups (n = 8 each). Untreated molars constituted the control group (group C); the rest of the teeth that underwent root canal therapy were restored with endocrowns composed of polycrystalline ceramics (ST zirconia, UPCERA) in group ZR, lithium disilicate glass ceramics (UP.CAD, UPCERA) in group LD, resin-based nanoceramics (Hyramic, UPCERA) in group NC, and feldspathic ceramics (CEREC Blocs, Sirona) in group FC.
View Article and Find Full Text PDFBiomolecules
January 2025
Department of Prosthodontics and Periodontics, Bauru School of Dentistry, University of São Paulo, Bauru 17012-901, Brazil.
This study evaluated the osteogenic potential of the bioactive glasses SinGlass (45S5) and SinGlass High (F18) in regenerating critical bone defects in rat calvaria. Both biomaterials promoted new bone formation around the particles, with the SinGlass High (F18) group exhibiting a higher rate of bone maturation. Histomorphological and birefringence analyses revealed better organization of the newly formed bone in the biomaterial-treated groups, and immunohistochemistry indicated the expression of osteogenic markers such as osteocalcin, immunostaining for bone morphogenetic protein 2 (BMP 2), and immunostaining for bone morphogenetic protein 4 (BMP 4).
View Article and Find Full Text PDFBeijing Da Xue Xue Bao Yi Xue Ban
February 2025
Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
Adolescence is defined as a population ranging from ten to nineteen years old. Permanent teeth in adolescents are of critical significance as they are actively involved in mastication, contribute to aesthetic appearance, play a role in pronunciation, and are integral to the growth and development of the stomatognathic system. Specifically, permanent teeth in adolescents comprise those with incomplete root development and those with complete root development but unstable gingival margin positions.
View Article and Find Full Text PDFInt J Paediatr Dent
January 2025
Pediatric Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
Background: The growing demand for esthetic restorative materials highlights the need to evaluate their marginal accuracy and fracture resistance to ensure optimal clinical outcomes for primary molars.
Aim: The aim was to assess the vertical marginal gap distance and fracture resistance of esthetic restorative materials after cyclic loading.
Design: Forty extracted primary molars were randomly divided into four groups: Group I, stainless steel veneered crowns with tooth-colored material; Group II, prefabricated monolithic zirconia crowns; Group III, yttria-partially stabilized zirconia computer-aided design/computer-aided manufacturing (CAD/CAM) crowns; and Group IV, hybrid ceramic CAD/CAM crowns.
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