Lee, T.N. (2015) Reiniging van gecontamineerd lithium disilicaat. thesis, Dentistry.
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Abstract
Objectives: The try-in procedure of a ceramic restoration is an important step before it can be permanently cemented. The ceramic surface after etching can be contaminated by saliva during the try-in phase. There are little independent studies on the cleaning efficacy of Ivoclean. This study evaluated the bond strength of lithium disilicate to a composite resin with and without saliva contamination and with and without cleaning using Ivoclean or water. Materials and Methods: Fifteen lithium disilicate discs (diameter: 17mm, thickness: 2mm) were divided at random in five groups, etched using 4.9% hydrofluoric acid and ultrasonic cleaned in demineralized water. Discs of group 1, 3 and 5 were contaminated with human saliva whereas groups 2 and 4 were left uncontaminated. The discs were cleaned with Ivoclean (G1-2), rinsed with water (G3) or underwent no cleaning (G4-5). All discs were treated with silane (Monobond Plus) followed by heat treatment and application of an unfilled resin (Adhese Universal). Tubes (N=60 and n=12 per group) filled with composite resin cement (Variolink Esthetic) were applied on each disk. All specimens underwent thermocycling (10.000 times, 5ºC to 55ºC). The shear bond strength (μSBS) was measured in a universal testing machine (1mm/min). The failure type was analyzed using a light microscope (x25). The results (MPa ± SD) were statistically analyzed with the one-way ANOVA and the post hoc analysis of Bonferroni. P-values smaller than 0.05 were considered significant. Results: Significant effects among the groups (p < 0.05) were observed on the bond strength (one-way ANOVA). Interaction terms were not significant (p > 0.05) for all groups (Bonferroni’s test). The bond strength of the group which was cleaned with Ivoclean after contamination (G1) showed a significant difference (p < 0.05) from the group which was not contaminated and cleaned with Ivoclean (G2). The group which was not cleaned after contamination (G5) showed a significant difference (p < 0.05) from the group which was not contaminated and cleaned with Ivoclean (G2). The group that was cleaned with Ivoclean after contamination (G1) showed no significant difference with the control group (G4) or the group that was not cleaned after contamination (G5). Adhesive failures between the cement and the substrate were observed in 63% of all specimens. Specimens that were not cleaned after the contamination with saliva, showed only adhesive failures (G5). Conclusion: A residual layer of saliva after cleaning with Ivoclean led to a significant reduction of the bond strength. Cleaning with Ivoclean after saliva contamination of lithium disilicate did not lead to comparable bond strengths as uncontaminated lithium disilicate.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Gresnigt, Dr. M.M.M. |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 11:06 |
| Last Modified: | 25 Jun 2020 11:06 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2562 |
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