Kuiper, M.C.F.M. (2013) Shear bond strength (SBS) of two resin composite luting cements to a new indirect CAD/CAM material and two ceramics. thesis, Dentistry.
![[img]](https://umcg.studenttheses.ub.rug.nl/style/images/fileicons/text.png) |
Text
Kuijperde.pdf Restricted to Registered users only Download (41MB) |
Abstract
Objectives: The main objective of this master thesis is to evaluate surface treatment modalities for the new CAD/CAM composite material Lava Ultimate using two dualcuring resin composite cements and compare this to a leucite-reinforced and lithium disilicate ceramic. The null hypothesis tested: there is no difference in bond strength between Lava Ultimate and the control. The following hypotheses will also be tested: 1. Conditioning with silica-coated aluminiumoxide particles will perform with higher bond strength values than using aluminiumoxide particles. 2. There will be no significant difference between bond strengths of Variolink II and Rely X Ultimate for the ceramic and Lava Ultimate material. Materials & Methods: Seventy CAD/CAM blocks were prepared (24 Lava Ultimate, 6 IPS e.max CAD and 6 IPS Empress CAD). Lava Ultimate blocks were randomly assigned to 1 of the 4 experiment groups: 1. Al203 airborne particle abrasion (50 IJm, 15 seconds), 2. bur-roughening, 3. CoJet (30 IJm, 15 seconds) and 4.hydrofluoric acid etching (5o/o, 20 seconds). IPS e.max CAD (group 5; 20s etching) and IPS Empress CAD (group 6; 60s etching) served as controls. Per study group, Variolink II (a) and RelyX Ultimate (b) were used as luting cements. Four cement cylinders were adhered per block to the conditioned surface via transparent polyethylene molds (internal diameter 3mm, height 5mm), with a total of 12 per study group. Notch-edge shear testing was applied with a cross head spead of 1 mm/min in a universal test machine. Modes of failures were examined under 25x magnification in a 4-point scale (1. cohesive substrate, 2. mixed, 3. cohesive cement and 4. adhesive). In all tests, a p-value of 0.05 was considered significant. Results: Specimens which contained air bubbles at the adhesive interface were excluded from the results (n=10). For the Variolink II specimens, a significant effect was obtained for the type of substrate on the bond strength (one-way ANOVA). The mean bond strength of group 6a, Empress CAD (20.61 ±4.10 MPa), was significantly higher than group 2a (11.61 ±3.39 MPa) and 4a (15.21 ±4.29 MPa), however not compared to groups 1a (18.68 ±3.81 Mpa) and 3a (17.09 ±3.40 MPa). For the RelyX Ultimate specimens, bond strength was significantly influenced by the substrate type (Kruskai-Wallis test). Stepwise step-down analysis revealed that all experiment groups performed with higher bond strength than group 5b, e.max CAD (0. 78 ±0.89 MPa). Compared to group 6b, Empress CAD (12.31 ±1.87 MPa), significant differences were noted for group 1b (18.12 ±2.84 MPa) and 4b (15.57 ±2.31 MPa), but not compared to groups 2b (12.34 ±1.72 MPa) and 3b (11.54 ±2.45 MPa). Group 1 b performed significantly better than all study groups. Failure mode analysis showed a significant association between bond strength values and mode of failure (chisquare), with a general increase in bond strength for type 1 and 2 failures. Groups 1 a, 3a, 6a and 1 b showed only type 1 and 2 failures, whereas group 5b failed exclusively at the adhesive interface (type 4). Conclusion: The null hypothesis cannot be supported or rejected solely on the aforementioned evidence. Combination of bond strength results and failure mode analysis suggests a comparable bond for surface treatment 1 and 3 compared to the controls in case of Variolink II. For RelyX Ultimate, treatment 1 showed a significant better bond compared to the controls. The second hypothesis is not substantiated by the findings of this thesis. As for the third hypothesis, evidence of this thesis suggest an influence of cement type on groups 1, 5 and 6.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Gresnigt, M.M.M. and Department of Oral Function and Biomaterials and Faculty of Dentistry and Dental Hygiene |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 10:56 |
| Last Modified: | 25 Jun 2020 10:56 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/1680 |
Actions (login required)
 |
View Item |