Objective: To determine if a recent bioactive cement provides acceptable lithium disilicate crown retention after long-term aging with monthly thermocycling.
Materials And Methods: Extracted molars prepared with flat occlusal, 20° taper, ~4 mm axial. Prepared teeth assigned to two groups for equal mean surface areas per group. Lithium disilicate crowns fabricated with occlusal bar to facilitate removal. Crowns etched with 9.5%HF and cleaned. Cements were Ceramir Crown & Bridge QuikCap (CM) and Ketac Cem Maxicap (KC). Before cementation, specimens stored in 37°C water. Crowns cemented with 196 N force, placed in 37°C, 100% humidity oven for setting. Specimens thermocycled (5-55°C) 5000 cycles monthly for 6 months; otherwise stored in phosphate buffered saline solution. Crowns removed axially at 0.5 mm/min. Removal forces recorded and stresses calculated using areas. Independent t-test (α = 0.05).
Results: Levene test not significant (P = 0.649). CM removal stresses and forces (P < 0.001) were higher (1.93 MPa, 261.4 N) compared to KC (1.06 MPa, 139.4 N). CM cement found principally on crown intaglio, KC found with most cement on prepared tooth. Chi-square significant (P < 0.001).
Conclusions: Following long-term aging with monthly thermocycling, lithium disilicate crowns were best retained by CM cement, however both cements are capable of retaining lithium disilicate crowns with preparations of ideal taper and length.
Clinical Significance: Results serve as a basis for bioactive cement selection for retaining lithium disilicate crowns. Without optimal axial length, taper of preparation or retentive features, Ceramir Crown and Bridge QuikCap offers a bioactive cement with improved long-term retention when compared to Ketac Cem Maxicap for lithium disilicate crowns.
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http://dx.doi.org/10.1111/jerd.12718 | DOI Listing |
Oral Health Prev Dent
January 2025
Purpose: This in-vitro study was conducted to assess the fracture resistance of resin-bonded ceramic endocrowns with different designs at varying intracoronal depths.
Materials And Methods: Forty-eight (n = 48) extracted mandibular first molar teeth were randomly divided into four groups (n = 12). In the control group, the specimens remained untreated.
J Prosthodont
January 2025
Division of Prosthodontics, Department of Restorative Sciences, University of Minnesota, Minneapolis, Minnesota, USA.
Purpose: This pilot study aimed to compare the flexural strength of Amber Mill CAD to IPS e.max CAD and to determine the impact of different crystallization protocols on the flexural strength of Amber Mill CAD ceramics.
Materials And Methods: Amber Mill CAD ceramic blocks of a known Vita Classic shade were selected for testing against control IPS e.
J Prosthet Dent
January 2025
Associate Professor and Director of Student Research, Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus, OH. Electronic address:
Statement Of Problem: Currently there is no regulatory requirement or international standard for the wear resistance of dental materials and therefore no need to test prior to market launch.
Purpose: The purpose of this in vitro study was to evaluate and compare the total volumetric wear characteristics of milled polymer infiltrated ceramic network (MPICN) and printed polymer resin (PPR) as substrates opposing five antagonists, human enamel (EN), lithium disilicate (LD), zirconia (ZR), MPICN, and PPR, and to evaluate and compare the volumetric wear of these same materials as antagonists.
Material And Methods: Ten of each antagonist for a total of 50 EN, LD (IPS e.
J Mech Behav Biomed Mater
January 2025
Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT, 06269, USA. Electronic address:
This study aims to investigate the effects of material compatibility, variable cooling rates, and crown geometry on thermal stress development in porcelain-veneered lithium disilicate (PVLD) and porcelain-veneered zirconia (PVZ) dental crown systems, and subsequently anticipate parameters for their optimum performance. An anatomically correct 3D crown model was developed from STL files generated using 3D scans of the experimental crown sample. Next, the viscoelastic finite element model (VFEM) based on the 3D crown model was developed and validated for anatomically correct bilayer PVLD and PVZ crown systems.
View Article and Find Full Text PDFBMC Oral Health
January 2025
Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8549, Japan.
Background: Resin cements often require substrate-specific pretreatment. Recently, universal adhesive systems have been introduced, simplifying procedures by eliminating the need for multiple adhesives and offering options that do not require light curing. This study investigated the bonding performance of universal adhesive systems combined with dual-polymerising resin cements on enamel, dentin, zirconia, lithium disilicate ceramics (LDS), and resin blocks.
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