Unexpected early loosening of rectangular straight femoral Zweymüller stems with an alumina-reduced surface after total hip arthroplasty-a prospective, double-blind, randomized controlled trial.

BACKGROUND: Alumina particles from the grit blasting of Ti-alloy stems are suspected to contribute to aseptic loosening. An alumina-reduced stem surface was hypothesized to improve osseointegration and show comparable short-term outcomes to those of a standard stem. METHODS: In this prospective, double-blind, randomized trial, 26 standard (STD) and 27 experimental new technology (NT) stems were implanted. The latter were additionally treated by acid etching and ice blasting to remove alumina particles from the grit-blasting process. Follow-up occurred at 12 and 24 months. Bone mineral density (BMD) around the stem was measured by a dual-energy x-ray absorptiometry device (DEXA). Radiographs were reviewed for alterations. Clinical scoring comprised the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Harris Hip Score (HHS). Survival rates were calculated up to 50 months. RESULTS: Lower mean BMD and more severe cortical hypertrophies were found in the NT group. At 12 months, radiolucent lines were observed mostly in the metaphyseal zone for both groups, with a progression tendency in the NT group at 24 months. At 12 months, pain scores and the WOMAC total and physical activity scores were significantly lower in the NT group, without any differences thereafter. The number of NT stem revisions amounted to 6 (24%) and 11 (41%) at 24 and 50 months, respectively. CONCLUSION: In the NT group, unexpected catastrophic failure rates of 41% caused by early aseptic loosening were noted within 50 months. Compared with the STD stems, NT stems lead to poor clinical and radiographic results. LEVEL OF EVIDENCE: II. TRIAL REGISTRATION: NCT05053048.

Robust and nanoparticle-free superhydrophobic cotton fabric fabricated from all biological resources for oil/water separation.

Traditional superhydrophobic cotton fabrics (SCFs) for oil/water separation were usually fabricated by surface coating with inorganic nanoparticles combined with nonrenewable and nonbiodegradable or even toxic fossil-based chemicals, which would lead to secondary environmental pollution after their lifetime. In this study, we report robust, nanoparticle-free, fluorine-free SFC, which was prepared by acid etching followed by surface coating with epoxidized soybean oil resin (CESO) and subsequent modification with stearic acid (STA). No toxic compound and no nanoparticle were included within the SCF and all the raw materials including cotton fabric, CESO and STA are biodegradable and derived from biological resources. The SCF showed excellent mechanical stability and chemical/environmental resistances. The superhydrophobicity of the SFC survived from mechanical abrasion, tape peeling, ultrasonication, solvent erosion and low/high temperature exposure. The SCF also exhibited good acid/alkali resistance with contact angle over 150° toward different pH water droplets. Moreover, the SCF could efficiently separate oil/water mixtures with efficiency above 97.9% and the superhydrophobicity remained after reusing for at least 10 times. The fully biological-derived SCF with excellent mechanical and chemical resistances exhibit great potential for separation of oil/water mixtures.

Effect of grape seed extract-containing phosphoric acid formulations on bonding to enamel and dentin

Abstract The aim was to evaluate the effect of 2% grape seed extract (GSE) containing phosphoric acid (PhA) on the bond strength to enamel and dentin. The control group was 37% PhA. The following three PhA formulations with 2% GSE and 20% ethanol were obtained: GSE5 = 5% PhA; GSE10 = 10% PhA; and GSE20 = 20% PhA. The enamel and dentin surfaces of molars were etched with the acid solutions, followed by Scotchbond Multi-Purpose adhesive and composite resin application. The tensile bond strength (TBS) test evaluated the bond to enamel after 24 h, and the microtensile bond strength (μTBS) test evaluated the bond to dentin after 24 h and 12-month water storage. Etched enamel and dentin were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The TBS data were submitted to one-way ANOVA, while µTBS data were submitted to two-way ANOVA and Tukey's test (α = 0.05). The TBS (MPa) to enamel did not significantly differ among the control (48.1 ± 15.7), GSE5 (46.1 ± 9.6), GSE10 (49.8 ± 13.6) and GSE20 (44.1 ± 11.9) groups (p = 0.537). The µTBS (MPa) to dentin of the control (28.4 ± 14.4) and GSE20 (24.1 ± 8.1) groups were significantly higher than those of the GSE5 (16.8 ± 7.4) and GSE10 (17.5 ± 6.6) groups at 24 h (p < 0.006). After 12-month storage, only GSE5 (21.0 ± 7.8) and GSE10 (17.6 ± 8.0) did not show significantly decreased μTBS (p > 0.145). SEM micrographs showed a shallower enamel etching pattern for GSE5. AFM images showed the formation of collagenous globular structures for GSE5 and GSE10. The different acid solutions did not influence the TBS to enamel, and the µTBS to dentin was stable over time when dentin was etched with GSE5 and GSE10.

Deproteinizing Agents as an Effective Enamel Bond Enhancer-An in Vitro Study.

OBJECTIVE: The aim of this study was to compare the effect of different deproteinizing agents on shear bond strength of composite to primary teeth enamel. STUDY DESIGN: Forty sound primary molars divided in 4 groups of 10 teeth each. In control group 1, enamel was etched for 60 seconds with 37% phosphoric acid and rinsed with water. Group 2: after acid etching deproteinizing agent 5 % sodium hypochlorite was applied for 60 seconds and rinsed. Group 3: after acid etching deproteinizing agent papain gel was applied for 60 seconds and rinsed. Group 4: after acid etching deproteinizing agent bromelain gel applied for 60 seconds and rinsed. Following this, bonding agent was applied to treated enamel surface and composite resin disc were build. Samples were then tested for shear bond strength using Universal Testing Machine. RESULTS: Mean SBS was highest for group 4 and lowest for group 1. No statistically significant difference (p value >0.05) was found between all the four groups. CONCLUSION: Among deproteinizing agents, deproteinization when carried out with bromelain gel and sodium hypochlorite showed effective bond strength as compared to papain.

Enhancement of osseointegration by direct coating of rhBMP-2 on target-ion induced plasma sputtering treated SLA surface for dental application.

Owing to the excellent bioactive properties of recombinant human bone morphogenetic proteins (rhBMPs), dentistry considers them as a fascinating adjuvant alternative for enhancing bone regeneration and bone-to-implant junction in the early implantation stages. However, stable loading and delivery efficiency of rhBMPs on the implant surfaces involve major concerns because of the harsh wearing condition under load during implantation. In this study, to achieve successful rhBMP-2 delivery, a nanoporous surface structure is introduced on the sandblasting with large grit and acid-etching (SLA)-treated titanium (Ti) surface via the tantalum (Ta) target-ion induced plasma sputtering (TIPS) technique. Unlike oxidation-induced surface nanoporous fabrications on a Ti surface, TIPS-treated surfaces provide excellent structural unity of the nanoporous structure with the substrate due to their etching-based fabrication mechanism. SLA/TIPS-treated Ti exhibits distinct nanoporous structures on the microscale surface geometry and better hydrophilicity compared with SLA-treated Ti. A sufficiently empty nanoporous surface structure combined with the hydrophilic property of SLA/TIPS-treated Ti facilitates the formation of a thick and uniform coating layer of rhBMP-2 on the surface without any macro- and microcoagulation. Compared with the SLA-treated Ti surface, the amount of coated rhBMP-2 increases up to 63% on the SLA/TIPS-treated Ti surface. As a result, the in vitro pre-osteoblast cell response of the SLA/TIPS-treated Ti surface, especially cell adhesion and differentiation behaviors, improves remarkably. A bone-regenerating direct comparison between the rhBMP-2-coated SLA-treated and SLA/TIPS-treated Ti is conducted on a defective dog mandible model. After 8 weeks of implantation surgery, SLA/TIPS-treated Ti with rhBMP-2 exhibits a better degree of contact area for the implanted bone, which mineralizes new bones around the implant. Quantitative results of bone-in-contact ratio and new bone volume also show significantly higher values for the SLA/TIPS-treated Ti with the rhBMP-2 specimen. These results confirm that an SLA/TIPS-treated surface is a suitable rhBMP-2 carrier for a dental implant to achieve early and strong osseointegration of Ti dental implants.

Micromorphology and bond strength evaluation of adhesive interface of a self-adhering flowable composite resin-dentin: Effect of surface treatment.

This study evaluated the effect of dentin surface treatment on the micromorphology and shear bond strength (SBS) of a self-adhering flowable composite, Vertis Flow (VF). Flat dentin surfaces obtained from sixty extracted human molars were divided into six groups (n = 10) according to the following surface treatments: (G1) control, no treatment; (G2) self-etching adhesive, Optibond All-in-One; (G3) phosphoric acid etching for 15 s; (G4) polyacrylic acid for 10 s; (G5) EDTA for 60 s; and G6) sodium hypochlorite (NaOCl) for 15 s. After restoration using VF, SBS was measured in MPa. Data were analyzed using one-way ANOVA and Tamhane test (α = 0.05). Six additional specimens were prepared for scanning electron microscopy analysis. SBS was significantly affected by surface treatment (P < 0.001). SBS of six groups from the highest to the lowest were as follows: (G3) 13.5(A); (G5) 8.98(AB); (G2) 8.85(AB); (G4) 8.21(AB); (G1) 7.53(BC); and (G6) 4.49(C) (groups with the same superscript letter were statistically similar). Morphological analysis revealed numerous long resin tags at the adhesive interface for acid-etched group, with a few short resin tags for the control group and small gap formation for NaOCl-treated group. In conclusion, dentin surface treatments tested differently affected bonding performance of VF; only acid-etching effectively improved this.

Addition of Grape Seed Extract Renders Phosphoric Acid a Collagen-stabilizing Etchant.

Previous studies found that grape seed extract (GSE), which is rich in proanthocyanidins, could protect demineralized dentin collagen from collagenolytic activities following clinically relevant treatment. Because of proanthocyanidin's adverse interference to resin polymerization, it was believed that GSE should be applied and then rinsed off in a separate step, which in effect increases the complexity of the bonding procedure. The present study aimed to investigate the feasibility of combining GSE treatment with phosphoric acid etching to address the issue. It is also the first attempt to formulate collagen-cross-linking dental etchants. Based on Fourier-transformed infrared spectroscopy and digestion assay, it was established that in the presence of 20% to 5% phosphoric acid, 30 sec of GSE treatment rendered demineralized dentin collagen inert to bacterial collagenase digestion. Based on this positive result, the simultaneous dentin etching and collagen protecting of GSE-containing phosphoric acid was evaluated on the premise of a 30-second etching time. According to micro-Raman spectroscopy, the formulation containing 20% phosphoric acid was found to lead to overetching. Based on scanning and transmission electronic microscopy, this same formulation exhibited unsynchronized phosphoric acid and GSE penetration. Therefore, addition of GSE did render phosphoric acid a collagen-stabilizing etchant, but the preferable phosphoric acid concentration should be <20%.

Effect of lingual enamel sandblasting with aluminum oxide of different particle sizes in combination with phosphoric acid etching on indirect bonding of lingual brackets.

OBJECTIVE: To compare bond strength and bond failure location of lingual brackets indirectly bonded after lingual enamel sandblasting with 27-, 50-, and 90-µm aluminum oxide particles followed by 37% phosphoric acid etching. MATERIAL AND METHODS: Eighty maxillary premolars were randomly divided into four equal groups according to the method of lingual enamel surface conditioning: Group 1 (control) was etched with 37% phosphoric acid, and group 2, group 3, and group 4 were sandblasted with 27-, 50-, and 90-µm aluminum oxide particles, respectively, prior to acid etching. Lingual brackets were indirectly bonded using the same protocol and adhesive (Sondhi) in all groups. The maximum shear bond strength required to debond the brackets was measured using a testing machine, and the bond failure location was classified according to the adhesive remnant index (ARI). Analysis of variance was used to compare the mean bond strength between groups. The differences between ARI scores were evaluated using the Kruskal-Wallis test. RESULTS: There were no statistically significant differences in mean shear bond strength or ARI scores between the four enamel-conditioning procedures. CONCLUSION: Lingual enamel sandblasting using different particle sizes of aluminum oxide prior to phosphoric acid etching did not increase the shear bond strength of indirectly bonded brackets and did not affect the amount of adhesive remnant on the enamel.

Micro-morphological changes prior to adhesive bonding: high-alumina and glassy-matrix ceramics

The aim of this study was to qualitatively demonstrate surface micro-morphological changes after the employment of different surface conditioning methods on high-alumina and glassy-matrix dental ceramics. Three disc-shaped high-alumina specimens (In-Ceram Alumina, INC) and 4 glassy-matrix ceramic specimens (Vitadur Alpha, V) (diameter: 5 mm and height: 5 mm) were manufactured. INC specimens were submitted to 3 different surface conditioning methods: INC1 - Polishing with silicon carbide papers (SiC); INC2 - Chairside air-borne particle abrasion (50 µm Al2O3); INC3 - Chairside silica coating (CoJet; 30 µm SiOx). Vitadur Alpha (V) specimens were subjected to 4 different surface conditioning methods: V1 - Polishing with SiC papers; V2 - HF acid etching; V3 - Chairside air-borne particle abrasion (50 µm Al2O3); V4 - Chairside silica coating (30 µm SiOx). Following completion of the surface conditioning methods, the specimens were analyzed using SEM. After polishing with SiC, the surfaces of V specimens remained relatively smooth while those of INC exhibited topographic irregularities. Chairside air-abrasion with either aluminum oxide or silica particles produced retentive patterns on both INC and V specimens, with smoother patterns observed after silica coating. V specimens etched with HF presented a highly porous surface. Chairside tribochemical silica coating resulted in smoother surfaces with particles embedded on the surface even after air-blasting. Surface conditioning using air-borne particle abrasion with either 50 µm alumina or 30 µm silica particles exhibited qualitatively comparable rough surfaces for both INC and V. HF acid gel created the most micro-retentive surface for the glassy-matrix ceramic tested.