IADR Abstract Archives
Veneer preparation and thickness influence the ceramic-composite-tooth interfaces – An OCT-evaluation
Objectives: Evaluation of the influence of the veneer preparation design and veneer thickness on the ceramic-composite and tooth-composite interfacial bond using optical coherence tomography (OCT) in vitro.
Methods: Sixty-four central incisors were randomly assigned to four groups (n=16 each) according to one of four preparation designs: non-prep (NP), minimally-invasive (MI, no dentin exposed), semi-invasive (SI, 50% dentin) and invasive (I, labial preparation, 100% dentin). Veneer restorations were fabricated from leucite-containing ceramic (Ceramic IPS InLine) in two subgroups of veneer thickness: 0.2-0.5 mm (T1) and 0.5-1.2 mm (T2). The veneers were etched (5% HF), silanized and adhesively luted using Optibond FL and the composite cement Variolink Veneer. After water storage (37°C, 21d), thermal cycling (2000 cycles, 5°-55°C) and mechanical loading (2+1 million cycles, 50+100N) specimens were imaged by spectral-domain OCT (Telesto II, Thorlabs; 1310 nm). Adhesive defects at the ceramic-composite (CC) and tooth-composite (TC) interfaces were quantified (length, %) per specimen on 35 equidistantly distributed B-scans of the OCT-image stack. Differences between interfaces (A) and (sub)groups (B) were assessed (Wilcoxon-/Mann-Whitney U-test, α=0.05).
Results: In all groups at both interfaces adhesive defects appeared with different degree [0.1% (MI-T2-TC) - 31.7% (I-T1-TC)]. A) In groups NP and MI for both thicknesses no significant differences between the interfaces could be found (all p>0.05). In groups SI and I significant more adhesive defects appeared at the tooth-composite interface compared to the ceramic-composite interface (all p≤0.039). B) Between the following preparation designs and veneer thicknesses different proportions of defects appeared (p≤0.021): Veneer-composite: NP-T1I-T2; Tooth-composite: NP-T1MI-T2, MI-T1Conclusions: The preparation design and the ceramic veneer thickness influence the interfacial bonding. By using leucite-containing ceramic veneers a minimally-invasive preparation combined with a ceramic thickness of at least 0.5 mm should be suggested.
Methods: Sixty-four central incisors were randomly assigned to four groups (n=16 each) according to one of four preparation designs: non-prep (NP), minimally-invasive (MI, no dentin exposed), semi-invasive (SI, 50% dentin) and invasive (I, labial preparation, 100% dentin). Veneer restorations were fabricated from leucite-containing ceramic (Ceramic IPS InLine) in two subgroups of veneer thickness: 0.2-0.5 mm (T1) and 0.5-1.2 mm (T2). The veneers were etched (5% HF), silanized and adhesively luted using Optibond FL and the composite cement Variolink Veneer. After water storage (37°C, 21d), thermal cycling (2000 cycles, 5°-55°C) and mechanical loading (2+1 million cycles, 50+100N) specimens were imaged by spectral-domain OCT (Telesto II, Thorlabs; 1310 nm). Adhesive defects at the ceramic-composite (CC) and tooth-composite (TC) interfaces were quantified (length, %) per specimen on 35 equidistantly distributed B-scans of the OCT-image stack. Differences between interfaces (A) and (sub)groups (B) were assessed (Wilcoxon-/Mann-Whitney U-test, α=0.05).
Results: In all groups at both interfaces adhesive defects appeared with different degree [0.1% (MI-T2-TC) - 31.7% (I-T1-TC)]. A) In groups NP and MI for both thicknesses no significant differences between the interfaces could be found (all p>0.05). In groups SI and I significant more adhesive defects appeared at the tooth-composite interface compared to the ceramic-composite interface (all p≤0.039). B) Between the following preparation designs and veneer thicknesses different proportions of defects appeared (p≤0.021): Veneer-composite: NP-T1