OCT evaluation of the internal adaptation of ceramic veneers depending on preparation design and ceramic thickness

• Published in: Dental materials Vol. 37; no. 3; pp. 423 - 431
• Main Authors: Haak, Rainer, Siegner, Juliane, Ziebolz, Dirk, Blunck, Uwe, Fischer, Sabine, Hajtó, Jan, Frankenberger, Roland, Krause, Felix, Schneider, Hartmut
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.03.2021; Elsevier BV
• Subjects: Adhesives; Ceramic; Ceramic bonding; Ceramic thickness; Ceramics; Composite materials; Defects; Dental Porcelain; Dental restorative materials; Dental Veneers; Dentin exposure; Dentistry; Design; Exposure; In vitro; Incisors; Interfaces; Internal adaptation; Laminate veneer; Materials Testing; Mechanical loading; OCT; Optical Coherence Tomography; Preparation design; Resin Cements; Teeth; Telesto; Thermal cycling; Thickness; Tomography, Optical Coherence; Veneers; Water storage; Preparation design; OCT; Ceramic thickness; Internal adaptation; Optical coherence tomography; Laminate veneer; Ceramic; Dentin exposure; In vitro
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/j.dental.2020.11.021

•Preparation design and veneer thickness influence the bond of ceramic veneers.•Leucite reinforced ceramic veneers should have a thickness of at least 0.5 mm.•If possible, the dentin should not be exposed during veneer preparation.•OCT permits non-destructive evaluation of the interfacial bond of ceramic veneers. In-vitro evaluation of the influence of preparation design and thickness of ceramic veneers on the interfacial bond using optical coherence tomography (OCT). Sixty-four central incisors were randomly assigned to four preparation designs differing from no to complete dentine exposure (n = 16 each): non-prep (NP), minimal-invasive (MI, no dentine exposure), semi-invasive (SI, 50% dentine) and invasive (I, 100% dentine). Ceramic veneers (IPS InLine Veneer) of two thicknesses (0.2−0.5 mm (T1) and > 0.5–1.2 mm (T2)) were etched, silanized, and adhesively luted (Optibond FL, Variolink Veneer). After water storage (37 °C, 21d), thermocycling (2000 cycles, 5°-55 °C), and mechanical loading (2 + 1 million cycles, 50 + 100 N) specimens were imaged by spectral-domain OCT (Telesto II, Thorlabs). Adhesive defects at the ceramic-composite and tooth-composite interfaces were quantified on 35 equidistantly distributed OCT B-scans (length, %). Statistical differences were verified with Wilcoxon-/Mann-Whitney-U-test (α = 0.05). Adhesive defects appeared in all groups at both interfaces, albeit to differing extents (0.1 – 31.7%). NP and MI veneers showed no significant differences at the interfaces (pi > 0.05). In groups, SI and I, significantly more adhesive defects appeared at the tooth-composite compared to the veneer-composite interface (pi ≤ 0.039). The following preparation designs and veneer thicknesses showed differences (pi ≤ 0.021): Veneer-composite: NP-T1 < I-T1, MI-T1 < I-T1, I-T1 > I-T2; Tooth-composite: NP-T1 < SI-T1, NP-T1 < I-T1, NP-T2 > MI-T2, MI-T1 < SI-T1, MI-T1 < I-T1, SI-T1 < I-T1, MI-T2 < SI-T2, MI-T2 < I-T2. The interface adhesion of ceramic veneers was influenced by the preparation design and the veneer thickness. A ceramic thickness of at least 0.5 mm and a preparation without exposing dentine is advantageous for the interfacial bond.