Abstract
The present study aimed to determine the influence of adhesive luting on the fatigue mechanical properties of simplified lithium disilicate crowns luted to dentin analogues preparations, and to compare two different approaches of simulation of a non-adhesive luting procedure. To this end, 30 prosthetic preparations of glass fiber-filled epoxy resin used as dentin analogues were milled and lithium disilicate crowns were pressed (1.5 mm thickness), which were allocated into three different groups: resin cement (RC), resin cement isolated by paraffin oil (RCI) and zinc phosphate cement (ZP). For luting procedures, the ceramic crowns of the RC and RCI groups had their internal surface treated with 5% hydrofluoric acid and universal primer. Afterwards, a thin layer of paraffin oil was applied onto the ceramic crown intaglio surface in the RCI group. The dentin analogues were treated with 10% hydrofluoric acid, followed by primer application and luting as recommended by the manufacturer. No previous surface treatments were performed for the ZP group, and the cement was applied as recommended. The fatigue test was run under cyclic fatigue (load 400–2000 N, step-size 100 N, 15,000 cycles/step, frequency 20 Hz) until failure detection (radial crack) by transillumination. The fatigue failure load (FFL), number of cycles until failure (CFF), and survival rate in each testing step were recorded. The RC group presented a higher FFL, CFF and survival rate compared to the other groups (p < 0.001), which were statistically equal to each other (p > 0.05). Weibull analysis detected no difference between groups for the Weibull module. Therefore, loss of adhesion between the evaluated substrates induces a significant reduction in load-bearing capacity under fatigue of the lithium disilicate crowns, strengthening the strong-importance of long-lasting adhesion for crown's survival. In addition, different methods for the simulation of non-adhesive conditions induce the same performance in the explored outcomes, confirming that both are valid approaches for laboratory studies.
| Original language | English |
|---|---|
| Article number | 105373 |
| Pages (from-to) | 1-7 |
| Number of pages | 7 |
| Journal | Journal of the Mechanical Behavior of Biomedical Materials |
| Volume | 134 |
| Early online date | 19 Jul 2022 |
| DOIs | |
| Publication status | Published - Oct 2022 |
Bibliographical note
Funding Information:This study was partly financed by the Brazilian Federal Agency for Coordination of Improvement of Higher Education Personnel ( CAPES ) (Finance code 001) and by the Foundation to Research Support of the Rio Grande do Sul State ( FAPERGS ARD October 2020 – Finance code 21/2551-0000679-0 ). We especially thank Ivoclar Vivadent for donating part of research materials. Finally, we emphasize that those institutions had no role in the study design, data collection or analysis, decision to publish or in preparing the manuscript.
Publisher Copyright:
© 2022 Elsevier Ltd
Funding
This study was partly financed by the Brazilian Federal Agency for Coordination of Improvement of Higher Education Personnel ( CAPES ) (Finance code 001) and by the Foundation to Research Support of the Rio Grande do Sul State ( FAPERGS ARD October 2020 – Finance code 21/2551-0000679-0 ). We especially thank Ivoclar Vivadent for donating part of research materials. Finally, we emphasize that those institutions had no role in the study design, data collection or analysis, decision to publish or in preparing the manuscript.
Keywords
- Adhesion
- Ceramics
- Crowns
- Dental cements
- Fatigue
- Reinforcement