Mechanical Roughening Research Articles

Biocompatible Composite Protective Thin Layer Containing Cellulose Fibers and Silica Cryogel

The aim of the present research was to synthesize protective composite layers from biodegradable cellulose and biocompatible, sol–gel-derived silica cryogel. An important task in the present work was to achieve good applicability on distinct (smooth and rough) surfaces of various materials (from metallic to ceramic). The aim was to utilize the composite layers as thermal and electric insulation coating. The investigation put some effort into the enhancement of mechanical strength and the elasticity of the thin layer as well as a reduction in its water solubility. The removal of the alkali content leads successfully to a significant reduction in water solubility (97 wt% → 1–3 wt%). Adhesion properties were measured using a specialized measurement technique developed in our laboratory. Treatments of the substrate surface, such as alkaline or acidic etching (i.e., Na2CO3, HF, water glass), mechanical roughening, or the application of a thin alkali-containing primer layer, strongly increase adhesion. SEM analyses revealed the interactions between the matrix and the reinforcement phase and their morphology.

Advanced Reclaimed Asphalt Pavement Treatment for Sustainable Pervious Concrete: Optimizing Strength, Hydraulic Performance and Long-Term Durability

The increasing depletion of natural aggregates and escalating construction waste necessitate the implementation of environmentally friendly substitutes in concrete production. This study explores the incorporation of treated Reclaimed Asphalt Pavement (RAP) as an eco-efficient alternative to traditional coarse aggregates in pervious concrete (PC) matrices by evaluating its structural integrity, permeability, durability, and microstructural characteristics. A comprehensive multi-stage treatment process involving solar heating, natural oxidation, and mechanical roughening was employed to enhance aggregate bonding and bitumen reduction. The treatment of RAP was conducted for three treatment durations: 0-month, 12 months, and 24 months. Coarse aggregates were substituted with 0%, 25%, 50%, 75%, and 100% RAP by weight, and all mixtures were cured for 90 days. The investigation focused on evaluating essential functional characteristics, including density, porosity, hydraulic conductivity, compressive and flexural responses, as well as durability under abrasion and chemical exposure to sulphate and chloride environments. Microstructural analysis utilizing Energy Dispersive X-ray Analysis (EDAX) demonstrated a substantial reduction in bitumen content, as evidenced by a declining carbon peak with increased treatment duration. Additionally, Scanning Electron Microscopy (SEM) micrographs revealed fewer voids, increased C-S-H formation, and improved bonding, with minor Interfacial Transition Zone (ITZ) variations across 12-month and 24-month treatments. The findings highlight that extended RAP treatment significantly improves density, reduces porosity, enhances compressive and flexural strength, and lowers permeability. Furthermore, 24-month treated RAP demonstrated superior durability, exhibiting enhanced abrasion and chemical resistance due to improved aggregate cohesion and matrix integration. This study establishes that pervious concrete with more than 50% RAP content, previously considered unviable, is structurally feasible when suitable treatment and gradation techniques are used, thereby advancing sustainable construction materials. Doi: 10.28991/CEJ-2025-011-04-019 Full Text: PDF

In Vitro Investigation of the Effect of Silanizing on the Repaired Bond Strength of Short-Fiber Composites Subjected to Surface Treatment with an Er;Cr:YSGG Laser, Sandblasting, or Bur

Background: This study aimed to evaluate the effect of various interfacial surface treatments on the repair micro shear bond strength (μSBS) of aged short fiber-reinforced composite (SFRC). Methods and Materials: The substrate and repair composite material used in the fabrication of eighty samples were SFRC (Ever-X posterior, GC). Based on the mechanical roughening method, the samples were divided into four categories: diamond bur, sandblasting, laser treatment, and a control group. Then, they were split into two groups using the chemical conditioning method: those using a universal glue that contains silane and those using a separate silane step before the universal adhesive that contains silane. After 40 days of immersion in distilled water at 37°C, the specimens were removed. Universal testing equipment was used to implement SBS testing. Using field emission scanning electron microscopy (FESEM), the surface topography of the composite material was examined after the roughening procedures. Results: Although the laser group had the highest μSBS value, there was no statistically significant difference in μSBS across the groups (P > 0.05). The results for μSBS were also not significantly different when using universal adhesive with or without an extra silanizing step (P > 0.05). Conclusion: Based on the results, the other groups' μSBS values were lower than those of the laser group. Incorporating a distinct silanization process before applying the universal adhesive that contained silane did not improve the μSBS either.

Functional organic adlayers for controlling the adhesion strength of electrolessly deposited copper on super-engineering plastics

Functional organic adlayers for controlling the adhesion strength of electrolessly deposited copper on super-engineering plastics

Comparative Analysis of Shear Bond Strength in Orthodontic Brackets Between Milled and 3D-Printed Definitive CAD/CAM Restorations

Objective: The objective of this study was to evaluate the effect of different surface treatment methods on the shear bond strength (SBS) of metal brackets bonded to two types of CAD/CAM composite restorations: milled and 3D-printed. Materials and Methods: A total of 160 flat-shaped specimens (10 × 10 × 2 mm3) were prepared from four different CAD/CAM composites; two milled (Lava Ultimate™ [LU] and Grandio™ [GR]) and two 3D-printed (Crowntec™ [CT] and C&B Permanent™ [CB]). These specimens underwent thermocycling (5000 cycles at 5–55 °C), then were categorized based on the surface treatment into four groups (n = 10): Group C (control, no surface treatment), Group HF (treated with 9.6% hydrofluoric acid), Group DB (mechanical roughening by a diamond bur), and Group SB (sandblasting using aluminum oxide). Metal brackets were bonded using Transbond XT Primer and universal adhesive, stored in artificial saliva for 24 h, then thermocycled again. Shear bond strength (SBS) was tested using a universal testing machine until bracket debonding occurred. The adhesive remnant index (ARI) was assessed using a stereomicroscope to quantify the residual adhesive following debonding. Result: Regarding material, GR and LU restorations had significantly higher SBS values compared to CT and CB, ranging from 13.90 MPa to 20.35 MPa. Regarding surface treatment, SB and HF groups showed significantly higher SBS values. The ARI scores showed different adhesive modes of failure, with higher instances of scores 0 and 1, which indicate no or minimal adhesive remaining. Conclusions: Both milled and 3D-printed materials had adequate SBS for clinical use, with milled materials showing superior results. Surface treatments like sandblasting and HF significantly improved bond strength, with adhesive failure being common.

Effect of adhesives and mechanical surface treatments on the hard relining of CAD-CAM denture bases.

Effect of adhesives and mechanical surface treatments on the hard relining of CAD-CAM denture bases.

High‐Speed Laser Surface Structuring for Thermal Spray Coating Preparation

The preparation of surfaces for coating processes is indispensable for maximal adhesion and good coating results. These technical surfaces can be treated by chemical, mechanical, or physical procedures. In thermal spray coating, grit blasting is a standard process for surface preparation. This mechanical roughening and activation of the surfaces is fast and easy to handle. On the negative side, the grit gets wasted and the generated pattern is inflexible. Therefore, attempts to substitute grit blasting with a laser application is discussed in this article. Herein, a theoretical evaluation of high‐speed laser surface texturing (LST) is performed to find limits and points for the optimization of these processes. To estimate the surface processing rates, continuous wave, nanosecond, and ultrashort pulse laser machined dimples and grooves are investigated, and results of the spray coatings are presented afterward. The steel substrates are coated with Stellite 6 and tungsten. Adhesion tests and coating structures are analyzed. In terms of the optimization of the laser texturing, in situ temperature measurements show the influence of the laser process speed on the thermal load of the substrate. The influence of the number of scanning repetitions on heat accumulation during LST is also analyzed.

Silanizing Effectiveness on the Bond Strength of Aged Bulk-Fill Composite Repaired After Sandblasting or Bur Abrasion Treatments: An in vitro Study

ObjectiveTo measure the repair shear bond strength (SBS) of an aged bulk-fill composite after different mechanical (diamond bur vs sandblasting) and chemical (universal adhesive with or without a previous silanization) surface treatments.Materials and MethodsBulk-fill composite (Filtek One Bulk Fill, 3M ESPE) was used to construct seventy-two specimens aged through 10,000 thermal cycles. The specimens were allocated into two groups (n = 36 each) according to the mechanical roughening: Db, treated with a diamond bur, and Sb, treated by sandblasting. Each group was further subdivided into three subgroups (n = 12 each) according to the chemical conditioning: Db-only and Sb-only, unconditioned specimens; Db-U and Sb-U, specimens were conditioned with silane-containing universal adhesive (Scotchbond Universal adhesive, 3M ESPE); and Db-S-U and Sb-S-U, specimens were conditioned with a silane agent (Prosil, FGM) before employing the universal adhesive. The same composite material was used for repair. An additional reference group was constructed to measure the cohesive strengths of the bulk-fill composite. SBS testing was performed using a universal testing machine at a crosshead speed of 1 mm/min, and the failure modes were evaluated by stereomicroscope. The surface topography of resin composite after roughening was assessed by scanning electron microscopy. SBS data were statistically analyzed by ANOVA, Tukey’s test and independent t-test.ResultsThe significantly highest SBS was recorded in the reference group (P ≤ 0.05). Sb-only obtained significantly higher SBS than Db-only (P < 0.001). No significant difference in SBS was noted between Db-U and Sb-U or Db-S-U and Sb-S-U. Likewise, no significant difference was observed between the subgroups treated with or without silane (P > 0.05).ConclusionThe sandblasted specimens demonstrated a higher repair SBS than the diamond bur-treated specimens. The use of an additional silanizing step before applying silane-containing universal adhesive did not enhance the SBS of the repaired composite.

Repair of Bulk-Fill and Nanohybrid Resin Composites: Effect of Surface Conditioning, Adhesive Promoters, and Long-Term Aging

The aim of the study was to investigate the effect of different repair procedures on the repair bond strength of bulk-fill and nanohybrid resin composites after different aging periods. The resin composite blocks (8 × 8 × 4 mm3) were prepared from a bulk-fill (reliaFIL Bulk) and a nanohybrid (reliaFIL LC) resin composite and grouped according to aging duration (6 months, 1 year, and 2 years). Following aging, the blocks were assigned to different surface treatments; air-abrasion with aluminum oxide powder, roughening with a diamond bur, and no treatment. After cleansing with phosphoric acid, a silane layer (Porcelain Primer) was applied on the surface of half of the specimens in each group. The specimens were subdivided into two groups (n = 5): Scotchbond Universal (3M Oral Care) and All-Bond Universal (Bisco). The blocks were repaired with the nanohybrid composite (8 × 8 × 8 mm 3). The repaired specimens were stored in distilled water (37 °C/24 h) and segmented into beams. Half of the beams were immediately subjected to microtensile μTBS testing (1 mm/min), while the other half was stored in distilled water (37 °C) for 6 months before testing. Failure modes were analyzed using stereomicroscope and SEM. Statistical analyses were performed with ANOVA and least significant difference tests (LSD) tests (p = 0.05). The extension of aging periods (6 months, 1 year, and 2 years) reduced the repair bond strength in some groups for both resin composites (p < 0.05). The air-abrasion and bur roughening improved the repair bond strength (p < 0.05). The silane application did not influence the repair bond strength and durability (p > 0.05). There was no difference among the universal adhesives in the same surface treatment groups (p > 0.05). The mechanical roughening treatments are necessary for the repair of resin composite. The universal adhesives might be used for the repair of resin composites regardless of silane content without prior silane application.

Effects of different universal adhesives and surface treatments on repair bond strength between resin composites.

This study aimed to evaluate the effects of different universal adhesives and surface treatments on the repair bond strength between resin composites. A total of 220 composite samples were divided into three groups according to the adhesive resin to be applied: 1) Scotchbond Universal, 2) G-Premio Bond, and 3) Peak Universal Bond. They were then divided into seven subgroups according to surface treatments (n=10): A) air abrasion, B) air abrasion+silane, C) hydrofluoric acid, D) hydrofluoric acid+silane, E) air abrasion+hydrofluoric acid+silane, F) silane, and G) no surface treatment (negative control). After surface treatment, a repair composite was applied. Samples aged in the thermocycle were subjected to micro-tensile bond strength testing. Cohesive strength values of 10 non-aged composite blocks were used as a positive control. Kruskal-Wallis and one-way ANOVA tests were used for statistical evaluation. Fractured surfaces were evaluated using a scanning electron microscope. In Scotchbond Universal and G-Premio Bond, the mean micro-tensile bond strength value of the no surface treatment subgroup was significantly lower than that of the positive control. All subgroups of Peak Universal Bond showed similar values to the positive control. While Scotchbond Universal and G-Premio Bond required mechanical roughening before adhesive application, Peak Universal Bond did not require any surface treatment. Different universal adhesives may show different repair bonding strengths with different surface treatments. Since achieving a standard in this regard can be associated with many independent factors, clinicians should determine how to apply the adhesive they use most effectively with the most appropriate surface treatment based on their own clinical experience.

Effect of surface treatments and flash-free adhesive on the shear bond strength of ceramic orthodontic brackets to CAD/CAM provisional materials.

To evaluate the effect of surface treatments and flash-free adhesive on the shear bond strength of ceramic orthodontic brackets bonded to materials used for the fabrication of CAD/CAM provisional crowns. Specimens (n = 160) from each provisional material (CAD-Temp and C-Temp) were categorized into four groups according to the surface treatment methods: C (no surface treatment), HP (37% H3PO4), DB (mechanical roughening by diamond bur), and SB (mechanical roughening by blasting). Maxillary central incisor ceramic brackets (Clarity™ Advanced ceramic brackets, 3M Unitek) were bonded to the conditioned provisional materials according to the used adhesive system (n = 20), APC PLUS or APC flash-free. All specimens were evaluated for shear bond strength testing (SBS) and the adhesive remnant index (ARI). Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests. C-Temp significantly recorded higher SBS than CAD-Temp (24.0 and 16.0MPa, respectively) (p < 0.001). DB and SB groups utilizing flash-free adhesive significantly recorded higher SBS (18.2 and 24.0MPa, respectively) (P < 0.05) compared to other groups in the tested materials. Higher ARI scores were recorded in CAD-Temp and flash-free adhesive. Mechanical surface treatments and flash-free adhesive would enhance SBS of ceramic orthodontic brackets to CAD/CAM provisional materials. The higher ARI scores reported with CAD-Temp and flash-free adhesive reduce chair time for excess removal. Bonding of orthodontic brackets to provisional restorations is a challenge for orthodontists in adult comprehensive cases that could be improved by an appropriate provisional material, surface treatments, and adhesive system.

Improvement of the adhesive capacity of SBR for footwear outsoles by surface activation and coating deposition with atmospheric pressure plasma

Abstract Looking for a cleaner alternative to halogenation in the preparation of rubber for bonding with leather in footwear, atmospheric pressure plasma treatments were applied on styrene–butadiene rubber (SBR). Its adhesive capacity was improved and the highest bond strength standards for footwear were met. Two optimal processes were identified: (1) Plasma polymerization of (3‐aminopropyl)triethoxysilane coatings on flat SBR and (2) plasma‐activation of mechanically roughened SBR. The improvement on coated, flat SBR was mainly due to its surface chemistry having greater concentrations of polar carbon–oxygen species than the untreated SBR. For plasma‐activated, mechanically roughened SBR, combined contributions of mechanical roughening and roughening by plasma irradiation were found. Coating flat SBR at 100 mm/s showed the best balance between improved bond strength and durability.

PES/PVC textile surface modification by thermo-chemical treatment for improving its hydrophilicity

PES/PVC textile surface modification by thermo-chemical treatment for improving its hydrophilicity

Atmospheric-pressure plasma treatments of NBR for the improvement of adhesion in footwear applications

Atmospheric-pressure plasma treatments of NBR for the improvement of adhesion in footwear applications

Experimental Investigations on Interface between Ordinary and Lightweight Aggregate Concretes Cast at Different Times

Experimental investigations on 12 push-off specimens with dimensions of 600 × 300 × 180 mm (200 × 180 mm shear plane) were presented. Models reflected the connection between ordinary concrete (NWC) substrate and lightweight aggregate concrete (LWAC) overlay. The main purpose of the study was to investigate behaviour of the interface between concretes cast at different times. Two different interface conditions were considered: Smooth and rough (obtained by graining). In the selected elements, additional reinforcement consisting of one ∅8 bar was injected. The elements were tested under load control. The failure of the specimens without interface reinforcement was violent and resulted from breaking of the adhesive bond. Specimens with shear reinforcement failed in a ductile manner, however, due to the low reinforcement area, the residual load capacity was much lower than the load recorded just before cracking. It was found that mechanical roughening of the surface can lead to degradation of the concrete structure. As a result, the load-carrying capacities of elements with smooth interface proved to be higher than the ultimate loads of elements with deliberately roughened contacts. Comparative analysis showed that the existing design procedures ACI 318-19, Eurocode 2, Model Code 2010, and AASHTO can lead to safe but conservative estimation of the actual resistance of the concrete interface.

Chemical and Mechanical Roughening Treatments of a Supra-Nano Composite Resin Surface: SEM and Topographic Analysis

Background: Repairing a restoration is a more advantageous and less invasive alternative to its total makeover. The aim of this study was to analyze the effects of chemical and mechanical surface treatments aimed at increasing the roughness of a supra-nano composite resin. Methods: 27 cylindrical blocks of microhybrid composite were made. The samples were randomly divided into nine groups (n = 3). The samples’ surface was treated differently per each group: acid etching (35% H3PO4, 30 s and 60 s), diamond bur milling, sandblasting and the combination of mechanical treatment and acid etching. The samples’ surface was observed by a scanning electron microscope (SEM) and a confocal microscope for observational study, and surface roughness (Ra) was recorded for quantitative analysis. Results: The images of the samples sandblasted with Al2O3 showed the greatest irregularity and the highest number of microcavities. The surfaces roughened by diamond bur showed evident parallel streaks and sporadic superficial microcavities. No significant roughness differences were recorded between other groups. The difference in roughness between the control group, diamond bur milled group and sandblasted group was statistically significant. (p &lt; 0.01). Comparison between the diamond bur milled group and the sandblasted group was also significant (p &lt; 0.01). Conclusion: According to our results, sandblasting is the best treatment to increase the surface roughness of a supra-nano composite.

Repair of defective resin composite restorations in primary teeth: current trends in Brazilian undergraduate Dental programs

Este estudo investigou o ensino do reparo de restauração direta de resina composta em dentes decíduos nos cursos de graduação em Odontologia no Brasil. Um questionário referente a este tópico foi desenvolvido e enviado por e-mail para 205 cursos de Odontologia entre maio e setembro de 2019. Os dados obtidos foram analisados descritivamente. A taxa de resposta foi de 43,4% e dos cursos respondentes, 82% incluíram esse tópico em seu currículo. As duas razões mais comumente relatadas para o ensino do reparo de restaurações de resina composta foram preservação da estrutura dentária (95,9%) e redução do risco de complicações pulpares (71,2%). No que diz respeito ao protocolo para reparo, poucos instituições (24,7%) ensinaram o desgaste mecânico da porção da resina a ser reparada com pontas diamantadas. Por outro lado, o condicionamento com ácido fosfórico da superfície preparada foi recomendado por 87,7% das instituições e 76,7% indicaram aplicação de adesivo na superfície preparada. O material mais comumente ensinado para reparo foi resina composta convencional. O ensino do reparo de restaurações de resina composta com falhas foi estabelecido dentro do currículo dos cursos de graduação em Odontologia no Brasil. No entanto, não há consenso sobre o protocolo clínico para reparo.

Silane Effect of Universal Adhesive on the Composite-Composite Repair Bond Strength after Different Surface Pretreatments.

This study investigated the impact of a separate silanization step on the repair bond strength of composite substrates using a universal adhesive after various mechanical surface treatments. Composite specimens were aged and exposed to the following mechanical roughening treatments: diamond bur abrasion, aluminum oxide sandblasting, or silica coating. The specimens were then either left untreated or conditioned with universal adhesive (Scotchbond Universal), or a silane coupling agent was applied before the use of the universal adhesive or a conventional adhesive (Optibond FL). The conditioned surfaces and fresh substrate (positive control group) were covered with repair composite, and microtensile bond strength testing was performed. The significantly highest bond strength was obtained in the positive control group. Repair bond strength of the universal adhesive applied after a separate silanization step was similar to that without prior silanization, independent of the mechanical surface treatment. Moreover, after silica coating, no significant differences in the repair bond strength were detected among the different adhesive treatments. In conclusion, a separate silanization step before surface conditioning with the universal adhesive does not enhance the repair bond strength. On silica-coated composite substrates, repair bond strength values of the universal adhesive were similar to those of the conventional adhesive.

Adhesive bonding of alumina air-abraded Ag-Pd-Cu-Au alloy with 10-methacryloyloxydecyl dihydrogen phosphate.

The aim of this paper is to study changes in the Ag-Pd-Cu-Au alloy surfaces by alumina air-abrasion process and effect of those changes on the adhesive bonding characteristic. Surface roughness, surface composition and chemical state of the alumina air-abraded alloys were analyzed by a confocal laser scanning microscope, an energy dispersive X-ray spectroscopy and an X-ray photoelectron spectroscopy. The results showed that the alumina air-abrasion changed the alloy surface by mechanical roughening, alumina remain and copper oxidation. Effect of the changes in the alloy surface on the adhesive bonding characteristic was examined by using a methyl methacrylate/tri-n-butylborane derivative (MMA/TBB) resin cement with the 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer. The shear bond strength test results indicated that the surface oxidation by the abrasion is the main contributor that improved the adhesive bonding rather than other effects such as mechanical roughening or alumina remain.

Adhesive bonding of FDM-manufactured parts made of ULTEM 9085 considering surface treatment, surface structure, and joint design

Additive manufacturing has become increasingly popular over the past years. One of the most commonly used additive manufacturing process is the fused deposition modeling (FDM). In FDM, components are produced by depositing a molten plastic filament layer by layer on a build platform. The deposition takes place in a heated build chamber. Despite the many positive characteristics, the process principle leads to one main disadvantage. The maximum size of FDM-manufactured parts is limited by the size of the build chamber. Bigger parts can only be realized as an assembly group. Adhesive bonding is a commonly used joining method in the industry to produce resilient parts especially for lightweight applications and to join dissimilar materials. The aim of this study is to investigate the influence of the adhesive type, the surface character of FDM parts, and the design of the bond area on the bond strength. The parts to be investigated are made of ULTEM 9085. Six different adhesives (acrylate resin, polyurethane adhesive, and epoxy resins) and their compatibility with the ULTEM 9085 parts are investigated. Considering the surface character, the influence of different pretreatments (mechanical roughening, plasma activation) and different surface structures are tested. The surface is modified by adding a positive air gap and an interface structure, and by varying the raster angle of the top layer. Regarding the design of the bond area, six different designs (finger, scarf, butt, tongue-groove, t-peel, and overlap joint) are investigated. The results show that the maximum lap shear strength can be achieved by using two-component epoxy resins. The adhesion between the ULTEM 9085 and the polyurethane as well as for the acrylate resin is insufficient but can be increased by roughening the surface mechanically or by adding a positive air gap to the surface. The investigations also show a positive effect of the plasma treatment but only for the combination of ULTEM 9085 with the polyurethane adhesive. The best results for different bond designs are reached with the scarf and the finger joint.