Surface Treatment Research Articles

Effect of Various Surface Treatments of Zirconia on its Adhesive Properties to Dentin: An In Vitro Study.

To assess the effectiveness of various surface treatments and adhesives on the bond strength of zirconia-based ceramic to dentin. Eighty samples of zirconia were subjected to the four-surface treatment protocols (sandblasting, 48% hydrofluoric acid (HF), 48% hydrofluoric acid + 70% nitric acid (HNO3) and no treatment (control) following which the samples from each group were subdivided into two subgroups (n = 10) based on the resin cement employed for cementation (RelyX U200 and G-Cem Linkforce). The bonded specimens were subjected to shear stress to measure the bond strength using Universal testing machine. To test the difference in bond strength among the eight study groups, the Kruskal-Wallis ANOVA test was applied and for comparison between cements in each group, Mann-Whitney U test was applied. The highest bond strength values were observed for 48% HF group cemented with G-Cem Linkforce resin cement (16.220 ± 1.574) and lowest for control group-RelyX (4.954 ± 0.972). G-Cem cement showed higher bond strength than RelyX for all surface treatments except 48% HF + 70% nitric acid. It can be inferred that 48% HF can etch zirconia and generate a porous structure that proves to be beneficial for bonding. The increasing demand for esthetics has led to the replacement of metal-ceramic materials with zirconia-based ceramics. However, the chemical inertness of zirconia to various conventional surface treating agents has continuously challenged researchers to discover a new surface treatment protocol that could enhance the bond strength of zirconia. How to cite this article: Yenamandra MS, Joseph A, Singh P, et al. Effect of Various Surface Treatments of Zirconia on its Adhesive Properties to Dentin: An In Vitro Study. J Contemp Dent Pract 2024;25(3):226-230.

Evaluation of Fibrin Clot Interaction with Dental Implant after Different Surface Treatments: An In Vitro Study.

The current study was carried out to assess the interaction between fibrin clots and dental implants following various surface treatments. In this investigation, 45 dental implants with dimensions of 16 mm in length and 5 mm in diameter were utilized. They were divided up into three groups, each consisting of fifteen samples. Group I: Control; Group II: Ultraviolet (UV) light treated; and group III: Sandblasted and acid-etching (SLA) treated. Healthy volunteers' venous blood samples were drawn into vacutainer tubes without the use of anticoagulants. The samples were centrifuged for 3 minutes at 2700 rpm in a table centrifuge. The entire implant was submerged in room-temperature liquid fibrinogen for 60 minutes. Then, scanning electronic microscopy (SEM) was used to examine each sample. The inter- and intragroup assessments were obtained using the Mann-Whitney U test and the Kruskal-Wallis test; p-values less than 0.05 were regarded as statistically significant. The maximum adhesion of fibrin clot was found in SLA treated group (2.42 ± 0.10) followed by the UV light-treated group (2.18 ± 0.08) and control group (1.20 ± 0.02). There was a statistically significant difference found between the three surface-treated groups (p < 0.001). All surface-treatment methods exhibit adhesion between the implant surface and the fibrin clot. However, the highest adherence of fibrin clot was found in SLA treated group compared to the UV light-treated and control group. The physical and chemical characteristics of an implant's surface have a significant impact on the way blood clots organize. At the interface between the implant and the bone, blood clot production can initiate and facilitate the healing process. How to cite this article: Jalaluddin M, Ramanna PK, Swain M, et al. Evaluation of Fibrin Clot Interaction with Dental Implant after Different Surface Treatments: An In Vitro Study. J Contemp Dent Pract 2024;25(3):276-279.

Impact of ZrO2 Content on the Formation of Sr-Enriched Phosphates in Al2O3/ZrO2 Nanocomposites for Bone Tissue Engineering.

This study investigates the profound impact of the ZrO2 inclusion volume on the characteristics of Al2O3/ZrO2 nanocomposites, particularly influencing the formation of calcium phosphates on the surface. This research, aimed at advancing tissue engineering, prepared nanocomposites with 5, 10, and 15 vol% ZrO2, subjecting them to chemical surface treatment for enhanced calcium phosphate deposition sites. Biomimetic coating with Sr-enriched simulated body fluid (SBF) further enhanced the bioactivity of nanocomposites. While the ZrO2 concentration heightened the oxygen availability on nanocomposite surfaces, the quantity of Sr-containing phosphate was comparatively less influenced than the formation of calcium phosphate phases. Notably, the coated nanocomposites exhibited a high cell viability and no toxicity, signifying their potential in bone tissue engineering. Overall, these findings contribute to the development of regenerative biomaterials, holding promise for enhancing bone regeneration therapies.

UVC Irradiation as a Surface Treatment of Polycarbonate to Generate Adhesion to Liquid Silicone Rubber in an Overmolding Process.

This study investigates the adhesion properties of polycarbonate (PC) and liquid silicone rubbers (LSR) through surface activation using ultraviolet C (UVC) radiation. While self-adhesive LSRs adhere easily to certain thermoplastic composites such as polybutylene terephthalate (PBT) and polyamides (PAs), bonding to PC typically requires surface treatment due to the lack of compatible functional groups. Previous methods like plasma or flame treatment have been effective, but the use of UVC radiation for surface activation remains unexplored. Through experiments, it was found that UVC surface activation, particularly with ozone-generating lamps, significantly enhances the peel strength between PC and self-adhesive LSRs. The study evaluates the impact of different irradiation times and lamp configurations on peel resistance, surface energy, and composite stability. Results show that UVC/ozone (wavelengths 254 nm and 185 nm) activation increases peel resistance, with distinct differences observed between LSR types. Additionally, the study examines the stability of UVC activation over time and under various storage conditions, highlighting its effectiveness for up to 36 months at room temperature. Furthermore, the relationship between surface energy and peel strength is analyzed, finding that UVC/ozone activation increases surface energy but does not consistently correlate with improved adhesion. The study concludes with a comparison of UVC/ozone activation to alternative surface treatment methods, emphasizing its advantages such as cost-effectiveness and stability while considering limitations regarding substrate compatibility and occupational safety aspects. Overall, UVC/ozone surface activation presents a promising approach for enhancing adhesion in PC-LSR composite systems and holds potential for applications across various industries.

Antibacterial Activity of Oregano (Origanum vulgare L.) Essential Oil Vapors against Microbial Contaminants of Food-Contact Surfaces.

The antimicrobial effect of eight essential oils' vapors against pathogens and spoilage bacteria was assayed. Oreganum vulgare L. essential oil (OVO) showed a broad antibacterial effect, with Minimum Inhibitory Concentration (MIC) values ranging from 94 to 754 µg cm-3 air, depending on the bacterial species. Then, gaseous OVO was used for the treatment of stainless steel, polypropylene, and glass surfaces contaminated with four bacterial pathogens at 6-7 log cfu coupon-1. No viable cells were found after OVO treatment on all food-contact surfaces contaminated with all pathogens, with the exception of Sta. aureus DSM 799 on the glass surface. The antimicrobial activity of OVO after the addition of beef extract as a soiling agent reduced the Sta. aureus DSM 799 viable cell count by more than 5 log cfu coupon-1 on polypropylene and glass, while no viable cells were found in the case of stainless steel. HS-GC-MS analysis of the headspace of the boxes used for the antibacterial assay revealed 14 different volatile compounds with α-Pinene (62-63%), and p-Cymene (21%) as the main terpenes. In conclusion, gaseous OVO could be used for the microbial decontamination of food-contact surfaces, although its efficacy needs to be evaluated since it depends on several parameters such as target microorganisms, food-contact material, temperature, time of contact, and relative humidity.

Evaluation of shear bond strength of labial veneers after sandblasting/micro-abrasion of prepared teeth by aluminum oxide particles. An in-vitro study

ObjectivesTo explore the feasibility and effectiveness of using sandblasting with aluminum oxide particles to improve the shear bond strength of labial veneer restorations in dentistry. Materials and MethodsA sample size of 50 extracted teeth was divided into five groups, with each group containing ten teeth (n = 10) subject to different treatment protocols. Group 1the control group, underwent conventional surface treatment for labial veneer restorations, including the application of phosphoric acid etchant and bonding protocols. Groups 2 and 3 underwent micro-abrasion using aluminum oxide particles alone for durations of 30 and 45 s, respectively. Groups 4 and 5 experienced a combined approach of micro-abrasion for 30 and 45 s, respectively, followed by conventional surface treatment. The shear bond strength test was performed on each specimen. The resulting modes of failure and surface characteristics were then examined under a digital microscope.The data was analyzed statistically using a one-way analysis of variance (ANOVA) and a post hoc test. ResultsSignificant differences were observed in shear bond strength among the five groups (p < 0.05). The group that underwent conventional + 45-second micro-abrasion treatment exhibited the highest mean shear bond strength (25.69 MPa), while the conventional (controlled) group had the lowest (9.01 MPa). ConclusionFusing sandblasting and aluminum oxide particles could improve the bond strength of labial veneer restorations. Yet, more research is needed to refine this technique for practical application. This includes a broad array of cement types, particle sizes, and clinical situations to ensure the long-term success of veneer restorations.

How do different intraoral scanners and milling machines affect the fit and fatigue behavior of lithium disilicate and resin composite endocrowns?

The aim of this in vitro study was to evaluate the effect of the combinations of two different intraoral scanners (IOS), two milling machines, and two restorative materials on the marginal/internal fit and fatigue behavior of endocrowns produced by CAD-CAM. Eight groups (n= 10) were considered through the combination of TRIOS 3 (TR) or Primescan (PS) IOS; 4-axes (CR; CEREC MC XL) or 5-axes (PM; PrograMill PM7) milling machines; and lithium disilicate (LD; IPS e.max CAD) or resin composite (RC; Tetric CAD) restorative materials. Specific surface treatments were applied to each material, and the bonding to its corresponding Endocrown-shaped fiberglass-reinforced epoxy resin preparations was performed (Variolink Esthetic DC). Computed microtomography (μCT) was performed to assess the marginal/internal fit, as well as a mechanical fatigue test (20 Hz, initial load = 100 N/5000 cycles; step-size = 50 N/10,000 cycles until a threshold of 1500 N, then, the step-size was increased if needed to 100 N/10,000 cycles until failure or a threshold of 2800 N) to evaluate the restorations long-term behavior. Complementary analysis of the fracture features and surface topography in scanning electron microscopy was performed. Three-way ANOVA and Kaplan-Meier test (α = 0.05) were performed for marginal/internal fit, and fatigue behavior data, respectively. PS scanner, CR milling machine, and RC endocrowns resulted in a better marginal fit compared to their counterparts. Still, the PM machine resulted in a better pulpal space fit compared to the CR milling machine. Regardless of the scanner and milling machine, RC endocrowns exhibited superior fatigue behavior than LD ones. LD endocrowns presented margin chipping regardless of the milling machine used. Despite minor differences in terms of fit, the ‘IOS’ and ‘milling machine’ factors did not impair the fatigue behavior of endocrowns. Resin-composite restorations resulted in a higher survival rate compared to glass-ceramic ones, independently of the digital devices used in the workflow.

Assessment of a novel electrochemically deposited smart bioactive trabecular coating (SBTC®): a randomized controlled clinical trial

ObjectivesA randomized controlled clinical trial of dental implants was conducted to compare the clinical properties of a novel electrochemically deposited calcium phosphate coating to those of a common marketed surface treatment.Material and methodsForty implants of the same brand and type were placed in 20 fully edentulous participants requiring mandibular implantation. The two study groups were defined by the surface treatment of the implants. 20 implants in the control group were coated via a commercial electrochemical surface treatment that forms a mixture of brushite and hydroxyapatite, while the remaining 20 in the test group were coated with a novel electrochemical Smart Bioactive Trabecular Coating (SBTC®). A split-mouth design was employed, with each participants receiving one control implant in one mandibular side and a test implant in the other. To mitigate potential operator-handedness bias, control and test implants were randomly assigned to mandibular sides. All cases underwent digital planning, implant placement with a static surgical guide, and participants received locator-anchored full-arch dentures. The primary outcome was implant stability (measured using Osstell ISQ) assessed at insertion, loading, and then 3 months, 9 months, and 2 years post-insertion. The secondary outcome was bone level change (in millimeters) over the 2-year observation period. Oral health-related quality of life (OHRQL) was monitored using the OHIP-14 questionnaire. Complications and adverse events were recorded.ResultsSuccessful osseointegration and implant stability were achieved in all cases, allowing loading. ISQ values steadily increased throughout the observation period. While no significant differences were observed between the SBTC® and control coatings, the test group exhibited a higher ISQ gain. Bone resorption was somewhat lower in the SBTC® but not significantly so. Patients' OHRQL significantly improved after denture delivery and remained stable throughout the follow-up. No complications or adverse events were observed.ConclusionsBased on the study results, we conclude that the new surface treatment is a safe alternative to the widely used control surface, demonstrating similar osseointegrative properties and time-dependent bone level changes. Further research may explore the broader implications of these findings.Trial registrationThe study is registered on clinicaltrials.gov under the identifier ID: NCT06034171.

An experimental approach to the study of amber processing in the Neolithic: technical analysis of the Siliņupe amber assemblage, 4 th mill. BC, Latvia

Abstract Amber appears in the archaeological material of the Eastern Baltic region in the Middle Neolithic and continues in intensive use until the end of the Neolithic. Four major amber-working centres are known in the Eastern Baltic, the least studied of which is the settlement of Siliņupe (4th mill. BC). Not yet widely applied in research on Stone Age amber technologies, but very promising, is an analytical approach combining experimental archaeology and traceology to study processing choices made in specific production stages (i. e., individual technological elements), revealing that fine-grained sandstone was favoured for surface grinding, while flint tools were most widely used for shaping and surface treatment, distinguishing three techniques, namely shaving, scraping and pressure flaking, each identifiable by characteristic features. The study suggests that amber and flint processing were largely intertwined, as pressure flaking along with indirect percussion (used for splitting amber) derive from flint processing, and in the case of pressure flaking, required specific know-how.

Hardly water-soluble pseudo-polyrotaxane nanosheets comprising polyethylene-oxide-modified polydimethylsiloxane and gamma-cyclodextrin

Abstract We have successfully prepared hardy water-soluble pseudo-polyrotaxane nanosheets composed of carboxy group-terminated polyethylene oxide (PEO)-modified polydimethylsiloxane and γ-cyclodextrin (CD). These pseudo-polyrotaxane nanosheets are more water-insoluble than previously reported pseudo-polyrotaxane nanosheets composed of pluronic—a triblock polymer comprising PEO, polypropylene oxide (PPO), and PEO—and β-CD, and have potential applications as surface treatment agents.

Progress of research on the bonding-strength improvement of two-layer adhesive-free flexible copper-clad laminates.

The arrival of the 5G era has placed high demands on the electronic products. Developing thin, light, and portable electronic products capable of simultaneously improving the transmission rate and reducing the signal delay and transmission loss is necessary to meet such demands. The traditional three-layer, adhesive, flexible copper-clad laminate (3L-FCCL) cannot satisfy these demands because of its adhesive component. The large thickness and poor heat resistance disadvantages of 3L-FCCL can be avoided with a two-layer, adhesive-free, flexible copper-clad laminate (2L-FCCL). However, 2L-FCCL has low bonding strength. This work introduces the selection of conductor materials and insulating base films for flexible copper-clad laminates. Modification studies aimed at increasing the bonding performance of 2L-FCCL are summarized based on three aspects. These modification techniques include the surface treatment of copper foils, modification and surface treatment of polyimide films, and surface treatment of liquid-crystal polymers. Prospects are further provided.

Enhancing bonding of fresh concrete to steel through Laser Surface Texturing

In this work, we investigated the adhesion between surface-treated stainless-steel samples and a standard cement mixture. Laser surface treatments such as Direct Laser Writing (DLW) and Laser-Induced Periodic Surface Structures (LIPSS) were employed, which resulted effective to reach up to 16-fold increase of adhesion compared to the untextured. A comparison with mechanical surface treatments, i.e., sandblasting, revealed that, although an increase of adhesion was achieved probably ascribable to the higher surface roughness, such improvement in terms of bonding strength was significantly lower than the one obtained with the laser surface texturing.

Effect of surface modification on the high temperature low cycle fatigue performance of LPBF 316L austenitic steel

In this study, high temperature low cycle fatigue (LCF) tests at 550 °C were conducted on LPBF (Laser powder bed fusion) 316L with three different surface states, including the As-built surface (AB), fill contour (FC) manufacturing surface, and the surface combining FC and electropolishing (FC + EP). The effect of surface treatment on the high temperature LCF performance of LPBF 316L was investigated. Experimental results showed that the FC + EP surface treatment had the most significant effect on enhancing life. The difference in enhancing the fatigue life behavior was mainly attributed to the various crack initiation mechanisms with different surface states. The cracks on the surfaces of AB and FC mostly originate from the powder adhesion areas and the boundaries of the melt pool, while FC + EP surface treatment weaken the damage induced by powder adhesion. Furthermore, a parameter representing the fatigue crack propagation driving force that considers the surface condition has been defined, and a proposed life prediction model can provide guidance for surface modification and post-treatment of additive manufacturing materials as well as other metal materials.

Suppression of Ag dewetting in submicron Cu@Ag particles in paste for improving sinter bondability through surface modification

Operating temperature of a wide-bandgap semiconductor-based power device can reach 300 °C, which requires a next-generation die-attach sinter material. Ag-coated Cu (Cu@Ag) particles have been considered as a low-cost filler material in pastes for sinter bonding, replacing pure Ag particles. However, there are two main problems: out-diffusion of core Cu and Ag dewetting. Although the Ag shell is sufficiently thick, Ag dewetting induces accelerated out-diffusion of the core Cu and the resultant Cu oxidation through the formation of thin Ag coating parts. Accordingly, a surface-modification method using stearic acid was developed to suppress Ag dewetting and improve the sinterability of Cu@Ag particles. Sinter-bonding characteristics were examined using pastes containing surface-modified submicron Cu@Ag particles. Sinter bonding was conducted at 250 °C under 10 MPa for 1–10 min with N2 blowing using eight types of initial and surface-modified submicron Cu@Ag particles with Ag contents of 10, 20, 30, and 40 wt% (A10, A20, A30, and A40). The shear strength of the bondline containing surface-modified A10 exhibited 17.56 MPa when bonded for 3 min, compared with 11.67 MPa of the initial A10. After a bonding time of 10 min, the shear strength increased to 20.41 MPa. Surface-modified A10 (low Ag content), with the highest efficiency in Ag dewetting suppression, exhibited sinter-bonding characteristics similar to those of Cu@Ag particles with higher Ag contents without surface treatment. Surface-modified A20 provided a sufficient strength of 20.83 MPa after 3 min of bonding.

Reagent‐Free Covalent Immobilization of Biomolecules in a Microfluidic Organ‐On‐A‐Chip

AbstractMicrofluidic systems have become integral for lab‐on‐a‐chip and organ‐on‐a‐chip applications across numerous disciplines. These systems, typically fabricated using polydimethylsiloxane (PDMS) chips on glass substrates, lack the bioactivity required for such applications. To overcome this, biomolecules are immobilized using either oxygen (O2) plasma treatment or chemical reagents like amino silanes. However, O2 plasma treatments are unstable and cannot covalently immobilize biomolecules, while wet‐chemistry approaches are toxic, time‐consuming, and expensive. A novel microfluidic platform that combines two plasma surface treatments: Plasma‐activated coating (PAC) and atmospheric pressure plasma jet (APPJ), to enable reagent‐free covalent immobilization of biomolecules is described here. These surface treatments, unlike O2 plasma, covalently immobilized fibronectin on PDMS and glass, and significantly improved endothelial cell attachment and proliferation. By combining PAC and APPJ, a hybrid microfluidic platform with equivalent bond strength to standard O2 plasma devices, but with significantly enhanced endothelial cell growth in and artery‐on‐a‐chip model, is developed. This platform is also amenable to high‐shear applications such as coronary shear, with endothelial cells aligning with flow, as seen in human arteries. By providing reagent‐free covalent immobilization of biomolecules within a microfluidic system, this technology has the potential to radically improve organ‐on‐a‐chip development as well as lab‐on‐a‐chip systems, point‐of‐care diagnostics, and sensors.

A Vision for LLZO Carbonate Formation: Perspectives on Surface Treatment Approaches and Characterization Techniques

AbstractLi7La3Zr2O12 garnets are among the most promising materials for solid‐state electrolytes thanks to their high electrochemical stability and ionic conductivity. However, they are unstable in air and easily undergo a Li+/H+ exchange reaction, forming a lithiophobic and poorly Li‐conducting surface layer composed of LiOH and Li2CO3 upon further reaction with CO2. Despite a simple reaction mechanism, protonation of LLZO is a complex phenomenon. The thickness and composition of the secondary phases on the surface depend on many parameters both in the LLZO properties and in the storage atmosphere. Due to this complexity, proposing a universal procedure for removing the secondary phases is not simple. However, understanding the role of different parameters and rational selection of characterization techniques makes it possible to find the optimal conditions for removing the LiOH/Li2CO3 layer and further processing each material. This work compares some of the main approaches for cleaning the LLZO surface and describes their advantages and shortcomings. Additionally, the strengths and limitations of the most common characterization techniques for analyzing the (de)protonation of LLZO (XRD, XPS, Raman, NMR, TGA) are explained to help researchers design their experiments more accurately.

Effect of Hybrid Surface Treatment Composed of Plasma Nitriding and DLC Coating on Friction-Wear Properties and Fatigue Strength of Alloy Tool Steel SKD11

Effect of Hybrid Surface Treatment Composed of Plasma Nitriding and DLC Coating on Friction-Wear Properties and Fatigue Strength of Alloy Tool Steel SKD11

Plasma surface treatment of bacterial cellulose to increase hydrophobicity

Plasma surface treatment of bacterial cellulose to increase hydrophobicity

Enhancing surface integrity in friction stir welding through deep rolling and post-weld heat treatment

This study aimed to investigate mechanical surface treatment through deep rolling (DR) and post-weld heat treatment (PWHT) to enhance the surface integrity of an AA7075-T651 aluminum alloy welded through friction stir welding (FSW). The surface integrity of the welded joint was evaluated by analyzing residual stress, microhardness, surface roughness, microstructure, and fatigue life. The experimental design comprised three sets: one set exclusively applied FSW, another set applied FSW followed by DR (FSW-DR), and the last set applied FSW followed by PWHT (FSW-PWHT). Fatigue testing (screening) was performed through a four-point bending test with a bending stress of approximately 300 MPa, test frequency of 2.5 Hz at room temperature, and stress ratio (R) of 0. The FSW parameters included a tool rotational speed of 1600 rpm, welding speed of 30 mm/min, immersion depth of 0.1 mm, dwell time of 15 s, and tool tilt angle of 0°. The DR parameters included a rolling pressure of 150 bar and rolling speed of 1400 mm/min. The results revealed that the residual stress significantly influenced fatigue life. The fatigue test demonstrated that FSW workpieces treated with the DR process (FSW-DR) exhibited the highest fatigue life, showing a remarkable increase of 33.5 % compared with that of untreated FSW workpieces. Moreover, the residual stress changed from tensile to compressive, accompanied by noticeable enhancements in microhardness and surface roughness. These results highlight that FSW followed by the DR process (FSW-DR) positively affects weld surface integrity, resulting in an extended service life for welded components.

Improved charge extraction in inverted perovskite solar cells with dual-site-binding ligands.

Inverted (pin) perovskite solar cells (PSCs) afford improved operating stability in comparison to their nip counterparts but have lagged in power conversion efficiency (PCE). The energetic losses responsible for this PCE deficit in pin PSCs occur primarily at the interfaces between the perovskite and the charge-transport layers. Additive and surface treatments that use passivating ligands usually bind to a single active binding site: This dense packing of electrically resistive passivants perpendicular to the surface may limit the fill factor in pin PSCs. We identified ligands that bind two neighboring lead(II) ion (Pb2+) defect sites in a planar ligand orientation on the perovskite. We fabricated pin PSCs and report a certified quasi-steady state PCE of 26.15 and 24.74% for 0.05- and 1.04-square centimeter illuminated areas, respectively. The devices retain 95% of their initial PCE after 1200 hours of continuous 1 sun maximum power point operation at 65°C.