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Purpose: To investigate the effect of tooth age on dentin adhesion of different luting systems to the root canal. Materials and Methods: 180 root canals of extracted teeth were divided into three age-specific groups (n = 60): young 20–35 (y), middle-aged 45–60 (m), and older 70–85 (o) years. Ten teeth of each age group were assigned to a luting system: Panavia 21 with ED Primer (P21, Kuraray); Core X Flow with Prime&Bond active and Self-Cure Activator (CXF, Dentsply Sirona); Multilink Automix with Multilink Primer (ML, Ivoclar Vivadent); Panavia SA Cement Plus (PSA, Kuraray); Smart Cem 2 (SM2, Dentsply Sirona); Speed CEM Plus (SCP, Ivoclar Vivadent). The root canals of decoronated teeth were instrumented with F360 (Komet) and BR7 (FKG) up to a working length of 8 mm (Ø0.6mm, taper 0.02) and filled with standardized steel spreaders and the selected material. The intracanal bond was determined by a pull-out test. The failure modes were categorized as an adhesive to dentin (AD), adhesive to spreader (AS), cohesive within the composite (C), and mixed (M). Statistical analysis was performed using non-parametric ANOVA, Tukey, and Chi-square test at a significance level of α ≤ 0.05. Results: The study showed significant differences for the various luting systems (ANOVA, P 0.05). PSA showed significant differences in bond strength to SM2, CXF, SCP, and ML, as did SM2 to P21 and SCP (Tukey, P 0.05). M (46%) occurred 53% in y and 70% in SCP. Conclusions: No adhesive strategy can yet be recommended for tooth age. Clinically available luting systems show significant differences in their adhesion values. Keywords: luting systems, post adhesion, root canal dentin, tooth age

Mit dem geplanten „Phase out“ von Dentalamalgam in der EU und der damit verbundenen, zum 1. Januar 2025 wirksamen neuen Behandlungsrichtlinie stellt sich in der Praxis nun eine konkrete Frage: Welches Material kommt für eine zuzahlungsfreie, plastische Restauration im Seitenzahnbereich infrage? Mit diesem Papier soll diese Frage beantwortet werden und es wird deutlich: Nicht alle „selbstadhäsiven“ Materialien sind auch wirklich für diese Indikation geeignet. Beim Blick auf die klinischen Daten zeigen sich Glashybride im Vorteil.

Purpose: The aim of this study was to evaluate the marginal quality and wear of bulk-fill composite resins (BFs) for Class-II restorations of primary and permanent molars in comparison to a conventionally layered composite resin (RC) and to compare the results of the two dentitions. Materials and Methods: Eighty (40 primary and 40 permanent) extracted molars received standardized Class-II cavity preparations and were restored with either one of two flowable BFs, one of two high viscous BFs, or a composite resin (RC). Thermomechanical loading (TML; 2,500 cycles +5°C/+55°C; 100,000 cycles, 50N, 1.67Hz) followed. A quantitative marginal analysis using SEM images and a profilometric quantification of two-body wear were carried out using replicas. ANOVA, Kruskal–Wallis, Mann–Whitney U, and Wilcoxon signed-rank tests were used for statistical analysis (P < 0.05). Results: For both dentitions, a significant reduction of perfect margins was observed after TML (P < 0.02). For the primary dentition, the flowable BFs showed significantly less perfect margins than all high viscous materials (P < 0.005). For the permanent dentition, RC showed significantly fewer gaps than the flowable BFs (P < 0.04). Regarding wear, within the dentitions, no significant differences could be computed between groups with regard to the maximum height loss (P < 0.05). Conclusion: All of the investigated bulk-fill composite resins showed satisfactory in-vitro results for both tested parameters in primary and permanent teeth, with a superiority of the high-viscosity materials in terms of marginal quality. Keywords: bulk-fill composite resins, marginal quality, permanent teeth, primary teeth, restoration materials, wear