Objectives: This study compared the influence of different inner crown surfaces on the fracture resistance and marginal adaptation of adhesively fixed glass fibre-reinforced molar crowns.
Materials And Methods: Vectris/Targis crowns were constructed with an inner framework of glass fibres (directly on the tooth) or an inner veneering composite layer between the fibre-framework and the tooth-substance. Both groups were sandblasted inside using Al(2)O(3); 50 microm grain size (200 kPa, 20 s) and silane coated. A control group had the inner fibre framework, but was neither sandblasted nor silane coated. The crowns were adhesively cemented on extracted human teeth, and thermally cycled and mechanically loaded (TCML: 6000 x 5 degrees C/55 degrees C; 1.2 x 10(6) x 50 N, 1.66 Hz). The marginal adaptation before and after TCML was evaluated and the fracture resistance was investigated using a Zwick universal testing machine.
Results: After TCML the proportion of 'perfect margin' of the control group decreased significantly at the interface crown/cement. For the variations with an inner fibre framework or inner composite layer the marginal adaptation or fracture resistance did not decrease significantly after ageing. The fracture resistance values were control: 1509N+/-486; inner fibre framework: 1896N+/-342; inner composite layer: 1754N+/-340.
Conclusions: In the case of the investigated fibre framework and veneering composite, the inner surface of glass fibre-reinforced molar crowns can be covered with a composite layer or with a glass fibre framework. Both methods achieve comparable high fracture strengths and reliable marginal adaptation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0300-5712(03)00072-1 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The Status of Wild Grapevine ( L. subsp. (C.C. Gmel.) Hegi) Populations in Georgia (South Caucasus).
Plants (Basel)
January 2025
National Wine Agency of Georgia, Tbilisi 0159, Georgia.
Repeated expeditions across various regions of Georgia in the early 2000s led to the identification of 434 wild grapevine individuals ( L. subsp. (C.
View Article and Find Full Text PDFPreheated and Injected Bulk-Fill Resin Composites: A Micro-CT Analysis of Internal Voids and Marginal Adaptation in Class II Restorations.
Materials (Basel)
January 2025
Department of Restorative Dentistry, School of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90619-900, Brazil.
The aim of this study was to evaluate, in vitro, the void formation and marginal adaptation in Class II cavities restored with preheated and injected bulk-fill resin composites. Eighty third molars received Class II cavities on their mesial and distal surfaces and were randomly distributed into eight groups (n = 10) according to material (Filtek Universal-control, incremental technique; Filtek One Bulk-Fill; Admira Fusion X-tra Bulk-Fill; VisCalor Bulk-Fill) and the temperature of the material (24 °C or 68 °C). The restored teeth were scanned using a SkyScan 1173 microtomograph.
View Article and Find Full Text PDFFarming of Indigenous Crayfish in Russia: A Mini-Review of Recent Studies.
Animals (Basel)
January 2025
Murmansk Marine Biological Institute of the Russian Academy of Sciences (MMBI RAS), 183038 Murmansk, Russia.
Natural populations of crayfish in Europe have experienced significant declines due to the spread of crayfish plague, overfishing, competition with invasive crayfish species, and habitat degradation. Consequently, crayfish farming has gained importance in meeting the increasing demand for crayfish products. Although Russia boasts abundant water resources, the development of crayfish aquaculture remains nascent.
View Article and Find Full Text PDFGenotype x environment interaction effect on grain yield of cowpea (Vigna unguiculata (L.) Walp) in Deciduous forest and Sudan savanna ecologies of Ghana.
PLoS One
January 2025
Department of Botany, University of Ghana, Legon, Ghana.
Cowpea is deemed as a food security crop due to its ability to produce significant yields under conditions where other staples fail. Its resilience in harsh environments; such as drought, heat and marginal soils; along with its nitrogen-fixing capabilities and suitability as livestock feed make cowpea a preferred choice in many farming systems across sub-Saharan Africa (SSA). Despite its importance, Cowpea yields in farmers' fields remain suboptimal, primarily due to biotic and abiotic factors and the use of either unimproved varieties or improved varieties that are not well-suited to local conditions.
View Article and Find Full Text PDFMarginal Gap Distance and Dynamic Fatigue Performance of Esthetic Crowns for Primary Teeth.
Int 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.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!