Influence of Pre-Treatment and Artificial Aging on the Retention of 3D-Printed Permanent Composite Crowns

Abstract

The aim of this in vitro study is to investigate the bonding properties of a 3D-printable permanent composite material in comparison to milled composite materials. The tested materials are 3D-printed BEGO VarseoSmile Crown plus (VA1_ab, VA1_nt, VA2_ab, VA2_nt), Vita Enamic (EN1, EN2), and 3M Lava Ultimate (UL1, UL2) (N = 64; n = 8). For this purpose, all crowns are luted to polymer tooth stumps #46 (FDI) using dual-curing luting composite, strictly according to the manufacturer’s instructions. VA1_ab and VA2_ab are additionally airborne-particle abraded. 4 groups (VA2_ab, VA2_nt, EN2, UL2) are artificially aged (1,200,000 cycles, 50 N, 10,000 thermocycles), whereby no specimen has failed. All 64 specimens undergo pull-off testing until retention loss. The mean forces of retention-loss is 786.6 ± 137.6 N (VA1_nt, *), 988.6 ± 212.1 N (VA2_nt, *, Ɨ), 1223.8 ± 119.2 N (VA1_ab, Ɨ, ǂ), 1051.9 ± 107.2 N (VA2_ab, *, Ɨ), 1185.9 ± 211.8 N (EN1, Ɨ, ǂ), 1485.0 ± 198.2 N EN2, ǂ), 1533.8 ± 42.4 N (UL1, ǂ), and 1521.8 ± 343.4 N (UL2, ǂ) (one-way ANOVA (Scheffé method); p < 0.05; *, Ɨ, ǂ: group distribution). No characteristic failure modes can be detected. In conclusion, all of the pull-off forces reflect retention values that seem to be sufficiently high for clinical use. Additional airborne-particle abrasion of VA does not result in significantly better retention but can be recommended.

Bond strength of additively manufactured composite resins to dentin and titanium when bonded with dual-polymerizing resin cements

“…The better bond strength to dentin of EN over that of more composite resin-like materials was also reported by Cekic-Nagas et al, 11 who attributed this difference to microstructural differences among the tested materials. Graf et al 6 compared the pull-off bond strengths of EN and VS crowns bonded to a glass fiber-reinforced highperformance polymer with dentin-like behavior and reported the significantly higher bond strengths of EN, which was consistent with the findings of the present study. One possible explanation for the better bonding performance of EN over CT and VS in the present study would be a higher degree of conversion from the controlled and optimized polymerization of the blocks from which the specimens were manufactured.…”

“…2,5 Manufacturers categorize these materials either as composite resins 2,3 or hybrid composite resins that comprise ceramic particles. 6 Hybrid materials are also among those that can be subtractively manufactured. One such material, containing 86 wt% ceramic and 14 wt% acrylate polymer network (urethane dimethacrylate and triethylene glycol dimethacrylate), [7][8][9][10] combines the advantages of composite resins and ceramics.…”

“…19 Dualpolymerizing resin cements were introduced to overcome the difficulty of light polymerizing beneath thick indirect restorations 20 and combine the advantages of light polymerizing and autopolymerizing resin cements. 21 Among the studies on the properties of additively manufactured definitive composite resins, 2,3,5,6,[22][23][24][25][26][27][28][29] only Graf et al 6 focused on their bonding properties. They investigated the effect of different surface treatments on the pull-off bond strength of crowns fabricated by using an additively manufactured definitive composite resin.…”

Evaluation of the Mechanical and Adhesion Characteristics of Indirect Restorations Manufactured with Three-Dimensional Printing

“…VarseoSmile Crown Plus (VSCP) was used as the 3D printing material in our study. This material is approved for use in single-tooth restorations, such as full crowns, inlays, and onlays [ 36 ]. The chemical content is as follows.…”

“…The average bond strengths of the 3D group were lower than those of the CS and SG groups. Notably, for objects produced by 3D printing, the likelihood of residual monomer retention is greater than that for subtractive resin matrix ceramics and composite resins [ 36 ]. As the number of monomers constituting the organic matrix decreases, the number of residual monomers decreases [ 51 ].…”