Höller B, Belli R, Petschelt A, Lohbauer U, Zorzin JI (2022)
Publication Type: Journal article
Publication year: 2022
Book Volume: 24
Pages Range: 57-66
Journal Issue: 1
Purpose: The present study investigated the influence of simulated intraoral conditions (increased temperature and humidity) on two different surface pretreatment methods to repair a lithium-disilicate glass-ceramic (LDS).Materials and Methods: A total of 540 rectangular lithium-disilicate glass-ceramic bars were manufactured (3×7×9 mm; IPS e.max CAD, Ivoclar Vivadent). Further specimen preparation was performed in an incubator with controlled relative humidity (RH) and temperature to simulate three different environmental settings: laboratory conditions (LC, n = 180, 23°C, 50% RH), rubber-dam conditions (RC, n = 180, 30°C, 50% RH) or oral conditions (OC, n=180, 32°C, 95±5% RH). One-third of the bars under each condition (n=60) were grit blasted (GBL) with alumina (35 μm at 1 bar pressure for 10 s and a working distance of 4±1cm) and primed (60 s, Monobond Plus, Ivoclar Vivadent). Another third (n=60) were pretreated with a self-etching glass-ceramic primer (MEP, Monobond Etch & Prime, Ivoclar Vivadent). One group without surface pretreatment (n=60, NoPT) served as a control. All pre treated surfaces were coated with Heliobond (Ivoclar Vivadent). Two bars from the same pretreatment method were luted perpendicular to each other with a resin composite to form a square adhesion area of 9 mm2(TetricEvo Ceram, Ivoclar Vivadent), and light cured for 20 s on each side (1200 mW/cm2, Bluephase 20i, Ivoclar Vivadent). All specimens were stored for 24 h in distilled water at 37°C. Half of the specimens from each environmental set ting and pretreatment method (n=15) were thermocycled (TC, 5000 cycles, 5/55°C, 30-s dwell time), and tensile bond strength (TBS) testing was performed for all groups using an x-bar rope-assisted set-up. Data were statisti cally analyzed using two-way ANOVA (α=0.05) with Bonferroni adjustment.Results Regardless of the environmental and storage conditions (24 h or TC), MEP showed a significantly higher mean TBS than GBL. A decrease in TBS was recorded in specimens under OC compared to RC and LC for both pre treatment methods independent of the storage condition. No significant difference in mean TBS was found be tween RC and LC within the MEP pretreatment group for the 24 h stored and thermocycled specimens. For all MEPs and GBLs, TC reduced the mean TBS in all environmental conditions. The NoPT groups showed no adhesion regardless of environmental or storage conditions.Conclusions: Increased temperature and high humidity significantly reduced TBS. However, MEP was less sensitive to environmental influences than GBL, which makes it a promising candidate for intraoral ceramic repair. These findings suggest that clinical intraoral repair of lithium-disilicate glass-ceramics should be performed using a rub ber-dam, primarily when using GBL.
APA:
Höller, B., Belli, R., Petschelt, A., Lohbauer, U., & Zorzin, J.I. (2022). Influence of Simulated Oral Conditions on Different Pretreatment Methods for the Repair of Glass-Ceramic Restorations. Journal of Adhesive Dentistry, 24(1), 57-66. https://doi.org/10.3290/j.jad.b2701717
MLA:
Höller, Benedikt, et al. "Influence of Simulated Oral Conditions on Different Pretreatment Methods for the Repair of Glass-Ceramic Restorations." Journal of Adhesive Dentistry 24.1 (2022): 57-66.
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