Although pre-treatment parameters for subtractive computer-aided design/computer-aided manufacturing (CAD/CAM) materials have been thoroughly investigated, data regarding additive restorative materials designed for permanent use in the oral cavity are scarce. This study investigated the effects of abrasive materials and blasting pressure on the bond strength of 3D-printed resins used in permanent restorations. A total of n = 44 test specimens additively manufactured from Formlabs' `Permanent Crown Resin' were prepared. Three groups with n = 11 specimens were airborne-particle abraded with 50 µm aluminium oxide at 1 bar, 2 bar or 3 bar. The control group did not receive any further airborne-particle abrasion after post-processing with 50 µm glass beads. Cylindrical superstructures were bonded to the prepared surfaces using RelyX Unicem 2. The bonded specimens were then subjected to artificial ageing via thermocycling. Subsequently, shear bond strength (sbs) tests were conducted. Data were analysed with the Kruskal-Wallis test (α = 0.05). After post-processing with glass beads, average shear bond strength values of 10.13 ± 7.62 MPa were achieved. When using aluminium oxide and 1 bar blasting pressure, significantly higher average sbs values of 25.57 ± 7.04 MPa were revealed (p = 0.009). The bond strength increased with higher blasting pressures (28.14 ± 6.35 MPa at 2 bar (p = 0.005); 30.15 ± 6.46 MPa at 3 bar (p < 0.001)). However, the shear tests revealed increased failure within the specimen base at higher blasting pressures. Bond strength significantly improved when airborne-particle abrasion with aluminium oxide was applied. However, increased airborne-particle abrasion pressure led to more failures at the base plate level of the specimens. Aluminium oxide increases the adhesive strength of 3D-printed dental restorative materials. Although the adhesive bond increased slightly with increasing airborne-particle abrasion pressure, the 3D restorative materials also exhibited an increased failure rate within the restorative material in the shear bond strength test with increasing blasting pressure.

Objective: To investigate the effectiveness of individual oral health care training (IndOHCT) on dental plaque removal and denture cleaning in hospitalized geriatric inpatients. Background: The literature reveals neglect of hygiene and oral care in people aged over 65 years, especially in persons in need of care. Hospitalized geriatric inpatients have poorer dental health than those non-hospitalized. Furthermore, the existing literature reporting on oral healthcare training interventions for hospitalized geriatric inpatients is scarce. Materials and Methods: This pre-post-controlled intervention study dichotomized 90 hospitalized geriatric inpatients into an intervention group (IG) and a control group (CG). Inpatients in the IG received IndOHCT. Oral hygiene was assessed using the Turesky modified Quigley–Hein index (TmQHI) and the denture hygiene index (DHI), at baseline (T0), at a second examination (T1a), and after supervised autonomous tooth brushing and denture cleaning (T1b). The influence of the Mini Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Barthel Index (BI) scores on oral hygiene was examined. Results: There was no significant plaque reduction on teeth or dentures between T0 and T1a in either group. Between T1a and T1b, plaque reduction on the teeth was more effective in the IG than in the CG (p < 0.001). Inpatients with 1–9 remaining teeth removed significantly more dental plaque than inpatients with 10 or more remaining teeth. Inpatients with lower MMSE scores (p = 0.021) and higher age (p = 0.044) reached higher plaque reduction on dentures. Conclusions: IndOHCT improved oral and denture hygiene in geriatric inpatients by enabling them to clean their teeth and dentures more effectively.

Polyetheretherketone (PEEK) is considered one of the most innovative prosthetic materials of the last few decades. Its chemically inert behavior and high biocompatibility make it a promising material in many areas of dentistry. The aim of this study was to test whether PEEK with different TiO₂ filler contents achieves comparable bond strength values when using different resin cements. N = 70 PEEK samples each with different TiO₂ filler content (20 wt.% TiO₂ vs. 5 wt.% TiO₂ vs. no filler as a control group) were divided into seven groups and cemented with various conventional (ResiCem, RelyX Ultimate, Variolink Esthetic DC) and self-adhesive resin cements (RelyXUnicem 2, Bifix SE, Panavia SA Cement Plus, SpeedCem). The shear strength of the bond was assessed after 24 h and after 25,000 thermal loading cycles. Mann-Whitney U and Wilcoxon tests were used for statistical analysis (significance level: α = 0.05). PEEK without filler showed the highest mean shear strength (24.26 MPa using RelyX Ultimate), then high-filled PEEK (22.90 MPa using ResiCem) and low-filled PEEK (21.76 MPa using RelyX Ultimate). Conventional resin cements generally achieved slightly higher adhesive strengths than self-adhesive resin cements. It appears that the filler content does not affects the adhesive bond strengths.

Ensuring a secure bond between a framework structure and layering composite resin veneer is essential for a long-lasting dental restoration. A variety of primer systems are available to facilitate the adhesive bonding. Nevertheless, the growing preference for efficiency and simplicity in dentistry has made the one-bottle universal primers a desirable option. This study aims to compare the effectiveness of universal primers on the shear bond strength (SBS) of base metal alloy (BMA) and zirconia to layering composite resin. Each 160 BMA and zirconia 20 × 10 × 5 mm test specimen was fabricated. Eight different primers (SunCera Metal Primer, Metal Primer Z, Reliance Metal Primer, Alloy Primer, MKZ Primer, Monobond Plus, ArtPrime Plus, and Clearfil Ceramic Primer Plus) were applied to 20 specimens in each group. Subsequently, a 5 × 2 mm composite resin build-up was applied. SBS tests were performed after 24 h of water storage and after thermocycling (25,000 cycles, 5–55 °C). On BMA, after water storage for 24 h, the bond strength values ranged from 26.53 ± 3.28 MPa (Metal Primer Z) to 29.72 ± 2.00 MPa (MKZ Primer), while after thermocycling, bond strength values ranged from 25.19 ± 1.73 MPa (MKZ Primer) to 27.69 ± 2.37 MPa (Clearfil Ceramic Primer Plus). On a zirconia base, after 24 h, the bond strengths values ranged from 22.63 ± 2.28 MPa (Reliance Primer) to 29.96 ± 2.37 MPa (MKZ Primer) and from 23.77 ± 3.86 MPa (Metal Primer Z) to 28.88 ± 3.09 MPa (Monobond Plus) after thermocycling. While no significant difference in bond strength was found between the primers on the BMA base, five primer combinations differed significantly from each other on zirconia (p = 0.002–0.043). All primers achieved a bond strength greater than 23 MPa on both framework materials after thermocycling. Thus, all primers tested can be applied to both framework materials with comparable results.