Acid Etching Procedure Research Articles

Adhesive Performance of Pit and Fissure Sealants on Deproteinized Enamel with Different Proteolytic Agents: In Vitro Study.

The objective of this work was to assess the efficacy of different proteolytic agents on the bond strength of pit and fissure sealants to bovine enamel. Eighty-four bovine enamel specimens were randomly assigned in groups according to the pit and fissure sealant applied (HelioSeal F or Dyad Flow). Then, the specimens were subdivided according to the proteolytic agent used (n = 7): Group 1, distilled water (control); Group 2, 10 wt.% Tergazyme®; Group 3, 10 wt.% ZYME®; Group 4, 10% papain gel; Group 5, 10% bromelain gel; and Group 6, 5.25 wt.% sodium hypochlorite. The cell viability of the proteolytic solutions was assessed through the MTT assay. The proteolytic agents were applied on the enamel surface prior to the acid-etching procedure; then, the pit and fissure sealants were placed. The micro-shear bond strength was evaluated after 24 h or 6 months of water storing at 37 °C. Representative SEM images were taken for each experimental group. The bond strength data were statistically analyzed by a three-way ANOVA test using a significance level of α = 0.05. Bromelain and papain proteolytic solutions did not exert any cytotoxic effect on the human dental pulp cells. After 24 h and 6 months of aging, for both pit and fissure sealants, sodium hypochlorite, papain, bromelain, and Tergazyme® achieved statistically significant higher bond strength values (p < 0.05). Irrespective of the deproteinizing agent used, Dyad Flow resulted in a better bond strength after 6 months of aging. The type 1 etching pattern was identified for sodium hypochlorite, papain, and bromelain. Tergazyme®, papain, and bromelain demonstrated efficacy in deproteinizing enamel surfaces prior to acid etching, leading to the improved bond strength of pit and fissure sealants. Clinically, this suggests that these proteolytic agents can be considered viable alternatives to traditional methods for enhancing sealant retention and longevity. Utilizing these agents in dental practice could potentially reduce sealant failures.

Double-size texturisation and biphasic calcium phosphate coatings obtained via laser technologies for bioactive zirconia dental implant surfaces

Commercial zirconia dental implants have a well stablished surface treatment to boost osseointegration based on grit-blasting and acid-etching procedures. Nevertheless, research studies aim to use laser surface texturing (LST) as an eco-substitute for commercial procedure. Moreover, LST allows the creation of designed patterns such as aligned grooves, cross-linked and spots. Laser technology also allows the bioactive coatings treatment, consisting in surface modification. This work designed three patterns in zirconia via LST and biphasic calcium phosphate 70HaP/30β-TCP coatings were laser treated. Analyses were performed via SEM, profilometry, XRD, and EDS to evaluate the quality of laser textures and bioactive coatings. Three different textures were successfully obtained. The cross-linked groove texture with squared ridges of 100 μm, groove width of 30 μm and 100 μm of depth. The micropit texture with aligned spots with 35 μm diameter, spaced by 15 μm and 30 μm depth. The third texture overlaps the previous textures, resulting in six spots per squared ridge. Laser treatment was found to be an expedited process for 70HaP/30β-TCP coating thermal treatment, resulting in a shaped and smooth coating.

Positive Effects of UV-Photofunctionalization of Titanium Oxide Surfaces on the Survival and Differentiation of Osteogenic Precursor Cells-An In Vitro Study.

The UVC-irradiation ("UV-photofunctionalization") of titanium dental implants has proved to be capable of removing carbon contamination and restoring the ability of titanium surfaces to attract cells involved in the process of osteointegration, thus significantly enhancing the biocompatibility of implants and favoring the post-operative healing process. To what extent the effect of UVC irradiation is dependent on the type or the topography of titanium used, is still not sufficiently established. The present study was aimed at analyzing the effects of UV-photofunctionalization on the TiO2 topography, as well as on the gene expression patterns and the biological activity of osteogenic cells, i.e., osteogenic precursors cultured in vitro in the presence of different titanium specimens. The analysis of the surface roughness was performed by atomic force microscopy (AFM) on machined surface grade 2, and sand-blasted/acid-etched surface grades 2 and 4 titanium specimens. The expression of the genes related with the process of healing and osteogenesis was studied in the MC3T3-E1 pre-osteoblastic murine cells, as well as in MSC murine stem cells, before and after exposure to differently treated TiO2 surfaces. The AFM determinations showed that the surface topographies of titanium after the sand-blasting and acid-etching procedures, look very similar, independently of the grade of titanium. The UVC-irradiation of the TiO2 surface was found to induce an increase in the cell survival, attachment and proliferation, which was positively correlated with an increased expression of the osteogenesis-related genes Runx2 and alkaline phosphatase (ALP). Overall, our findings expand and further support the current view that UV-photofunctionalization can indeed restore biocompatibility and osteointegration of TiO2 implants, and suggest that this at least in part occurs through a stimulation of the osteogenic differentiation of the precursor cells.

Collagen-depletion strategies in dentin as alternatives to the hybrid layer concept and their effect on bond strength: a systematic review

Strategies aiming to improve the longevity of resin–dentin adhesive interface developed so far have only been able to retard the problem. Different approaches are thus needed. The objective of this review was to determine whether the use of collagen-depletion strategies after acid-etching procedures may improve the bond strength of resin-based materials to dentin. A systematic review was planned following 2021 PRISMA statement guidelines, with a search strategy performed in five electronic databases: PubMed/Medline, Scopus, EMBASE, SciELO and IADR Archive (last search: 17/01/2022). Inclusion criteria encompassed studies which evaluated a collagen-depletion strategy in acid-etched human dentin and tensile/shear bond strength tests. Risk of bias assessment was carried out by two reviewers, working independently on an adapted five-domain risk of bias (RoB) checklist for laboratory studies. Results were synthesized qualitatively, as a meta-analysis was not possible due to limited number of studies and their RoB. A total of eight studies were eligible for inclusion in the systematic review after inclusion/exclusion criteria application. Out of these, two evaluated the effect of using NaOCl followed by an antioxidant, and the remaining six evaluated different enzymatic treatments (bromelain, chondroitinase ABC, papain, and trypsin). None of the studies reported a decrease of bond strength when a collagen-depletion strategy was used, in comparison to traditional hybrid layers (control). All enzymatic treatment studies which respected the inclusion criteria improved the bond strength to dentin. Some specific collagen-depletion strategies seem to play a favorable role in improving immediate bond strengths to dentin. Further research with sound methodology is required to consolidate these findings, since limitations in RoB and a low number of studies were found. The assessment of further proteolytic agents and long-term outcomes is also required.

Constructing pore arrays on nitrogen-doped carbon to boost potassium-ion storage capacity

The structural design of porous carbon materials is a research hotspot in potassium-ion batteries. More often than not, the pores are randomly distributed without intentional size regulation. In this work, we tried to construct well-defined pore arrays on nitrogen-doped carbon materials through an acid-etching procedure. In this strategy, strong acid attacked metal-oxide laden carbonous materials, leaving only carbon skeletons. The final aperture and pore alignment depended exclusively on the size and distribution of pristine metal oxides in carbon matrix. After electrochemical tests, it was found that porous carbon materials would experience an evolution process to achieve optimal pore configuration that was beneficial to the promotion of K+-storage capacity. This process was highly relevant to the initial pore configuration of carbon materials. The more ordered pore alignment and smaller aperture, the quicker pore evolution and better cycle/rate performance (e.g. 300.6 mAh g−1 at 0.1 A g−1 after 500 cycles and 218.1 mAh g−1 at 5 A g−1).

Evaluation of Class II Restoration Microleakage with Various Restorative Materials: A Comparative In vitro Study.

Background and Objectives:The quest for a suitable esthetic material for tooth restoration has resulted in significant advancements in both material properties and application technique. Composites and acid-etch procedures are two significant advancements in esthetic restorative dentistry. Further research has strengthened composites' overall wear resistance and strength, but the problem of polymerization shrinkage has persisted. To reduce polymerization shrinkage and microleakage, a variety of techniques and material modifications have been suggested. The marginal leakage of amalgam, packable composite, flowable composite with packable composite, and high-viscosity traditional glass ionomer cement (GIC) was compared in this analysis to test the mentioned hypothesis.Materials and Methods:We chose 60 freshly extracted teeth and divided them into four classes of 15 teeth each. Class II cavities were prepared in a standardized manner. Group I was treated with amalgam, Group II with packable composite (GC G-aenial Posterior), Group III with flowable composite (G-aenial Universal Flo) as a liner and then restored with packable composite (GC G-aenial Posterior), and Group IV with high-viscosity traditional GIC (EQUI FORTE FILL). After that, the restorations were put through a thermocycling process. The specimens were soaked in 0.5% methylene blue dye before being cut into mesiodistal sections to assess microleakage at the gingival margin. After that, the parts were examined under a stereomicroscope. The degree of dye penetration was used to determine the score.Results:There was no microleakage in the control group, and the gap between the control and experimental groups was statistically significant (P = 0.017).Conclusion:The glass hybrid restorative device had less gingival microleakage than the resin-based restorative material, indicating that it has a better sealing capacity. Clinical acceptability of glass hybrid restorative systems, on the other hand, must be confirmed with a larger sample size and in vivo trials.

Ni3N nanoparticles on porous nitrogen-doped carbon nanorods for nitrate electroreduction

Electrocatalytic nitrate reduction into recyclable ammonium under mild conditions provides an efficient and clean ammonium production strategy and remediation of nitrate-containing wastewater. In this work, we successfully synthesize the Ni3N nanoparticles anchored on nitrogen-doped carbon (Ni3N/N-C) nanohybrids through simple calcination and acid etching procedures using Ni-dimethylglyoxime complex (Ni-DMG) nanorods as raw material. Physical characterizations confirm that as-synthesized Ni3N/N-C nanohybrids have the high specific surface area of 665.7 m2 g−1 and the ultrafine Ni3N nanoparticles (5.3 nm) are dispersed uniformly on the surface of porous nitrogen-doped carbon nanorods. The electrochemical experiments indicate that the combination of nitrogen-doped carbon can greatly improve electroactivity of Ni3N nanoparticles for nitrate reduction reaction. Consequently, Ni3N/N-C nanohybrids possess high selectivity for ammonium production (89.5%) and high yield rate of ammonium (9.185 mmol h−1 mgNi3N−1) for nitrate electroreduction. Additionally, Ni3N/N-C nanohybrids also show excellent long-term stability due to their structural/chemical stability.

Sex estimation of teeth at different developmental stages using dimorphic enamel peptide analysis.

This study tests, for the first time, the applicability of a new method of sex estimation utilizing enamel peptides on a sample of deciduous and permanent teeth at different stages of mineralization, from nonadults of unknown sex, including perinates. A total of 43 teeth from 29 nonadult individuals aged from 40 gestational weeks to 19 years old were analyzed. The sample included pairs of fully mineralized and just developing teeth from the same individual. The individuals were from four archaeological sites in England: Piddington (1st-2nd centuries AD), Coach Lane, Victoria Gate, and Fewston (all 18th-19th centuries). A method that identifies sex chromosome-linked isoforms of the peptide amelogenin from human tooth enamel was applied. The method utilizes a minimally destructive acid etching procedure and subsequent nano liquid chromatography tandem mass spectrometry. It was possible to determine the sex of 28 of the nonadult individuals sampled (males = 20, females = 8, undetermined = 1). Only one sample failed (CL9), due to insufficient mineralization of the sampled tooth enamel. Data are available via ProteomeXchange with identifier PXD021683. Sufficient peptide material to determine sex can be recovered even from the crowns of developing perinatal teeth that are not fully mineralized. The minimally destructive and inexpensive (compared to ancient DNA) nature of this procedure has significant implications for bioarchaeological studies of infancy and childhood.

Preventive resin restoration - A narrative review

Conventional restorative dentistry methods persist predominant in the treatment of carious, even incipient carious, lesions when deterrence or remineralization must be the treatment of choice. According to preventative extension, when the tooth is prepared, all pits and fissures are eliminated with a bur to comfort the placement of amalgam. Lacking to acknowledge the significance and advantage of conservation of as much tooth structure as possible is indefensible in light of the technique options that the acid-etch procedure and the new resin materials offer the profession. The preventive resin restoration has several advantages. One of the important advantages is minimal tooth structure is removed compared with a conventional preparation, leaving a much stronger tooth. This is in contrast to the extension for prevention method by which elimination of better tooth structure to prevent repetitive decay at the same time weakens the tooth. As mentioned, the sealed restoration can eliminate recurrent caries.

Rational design of iron single atom anchored on nitrogen doped carbon as a high-performance electrocatalyst for all-solid-state flexible zinc-air batteries

Developing a cheap and high-efficiency oxygen reduction reaction (ORR) catalyst is vitally important for high-performance metal-air and full cell batteries. Non-noble iron-nitrogen-carbon materials (Fe-N-C) are reported with outstanding ORR property. However, most of them needs complex acid etching procedure during the fabrication process. Herein, we report a simple route to obtain a cost-effective Fe-N-C electrocatalyst via a facile two-step polymerization-pyrolysis process, and no acid etching is involved. Through a conjunction process of phthalocyanine iron (FePc) with polypyrrole (PPy) and a followed pyrolysis step, atomically evenly dispersed Fe-N-C species on nitrogen doped carbon can be easily obtained. Predictably, the obtained optimal catalyst delivers a half-wave potential of 0.83 V vs reversible hydrogen electrode (RHE) and better stability toward ORR test. Based on the optimal Fe single atomic catalyst as air cathode, an all-solid-state flexible Zn-air battery delivers a high open circuit voltage of 1.42 V, a high energy density of 833 Wh kg−1 and a high power density of 70 mW cm−2. The superior electrochemical energy storage properties demonstrated by the Fe-N-C electrocatalyst show a bright window for reasonable construction of cost-effective non-noble Fe single atom electrocatalysts for next-generation flexible energy storage devices.

Effect of Etching Procedures on the Adhesion of Biofilm-Coated Dentin.

Oral biofilms coat all surfaces in the oral cavity including the exposed dentin surface. This study aimed to investigate biofilm removal by acid etching procedures and the effects of the residual biofilm on dentin surfaces on composite–dentin adhesion. Dentin discs were assigned to five groups: no biofilm formation (C); biofilm formation and no surface treatment (BF); biofilm formation and acid etching (BF-E); biofilm formation and acid etching followed by chlorhexidine soaking (BF-EC); and biofilm formation and rubbing with pumice, followed by acid etching (BF-RE). Biofilms were formed on saliva-precoated dentin discs by soaking the discs in Streptococcus mutans (S. mutans) suspension. Biofilm removal from the dentin surface was evaluated quantitatively and qualitatively by confocal laser scanning microscopy and scanning electron microscopy, respectively. To compare the bond strength of the biofilm-coated dentin discs with the surface treatments, specimens were assigned to four groups: no biofilm formation and acid etching (C-E); BF-E; BF-EC; and BF-RE. Assessments of the micro-shear bond strength and subsequent failure modes were performed. BF-E and BF-EC did not remove the biofilm, whereas BF-RE partially removed the biofilm attached to the dentin (p < 0.05). The bond strength of BF-RE was significantly higher than those of BF-E and BF-EC, but lower than that of C-E (p < 0.05). In conclusion, mechanical biofilm removal is recommended before etching procedures to enhance adhesion to the biofilm-coated dentin.

Comparison of shear bond strength of traditional 3-step composite with self etch primer and composite.

The revolution in orthodontics has been due to replacement of cemented bands by orthodontic brackets. Acid etching is required to bond a bracket on tooth’s surface. Traditional three step acid etch procedure consisted of etching, sealing/priming and bonding. The self etch system (etchant and primer together) can be used without the need for surface preparation, saving chair side time and minimizing contamination. Objectives: To compare the shear bond strength (SBS) of orthodontic bracket bonded with Conventional etching primer (Transbond XT, 3M Unitek) with self etch primer (Adper Prompt L-Pop, 3M ESPE). Study Design: Prospective study Setting: Orthodontic Clinic of Ihsan Mumtaz Hospital, Lahore and PCSIR (Lahore). Period: 6 months from June 2018 to December 2018. Material and Methods: 60 human maxillary premolars were randomly divided into 2 groups of 30 each. Group-I was bonded with conventional etching primer + composite and Group-II was bonded with self etch primer + composite. Shear bond strength was measured through Ionstron force testing machine. Statistical Analysis: For each variable, shear bond strength, arithmetic mean, standard deviation, minimum and maximum values were calculated. t-test was used to compare the shear bond strength (SBS) of the two groups and P value less than and equal to 0.05 was considered significant. Results: The mean shear bond strength in group 1 and group II was10.5MPa and 7.36MPa respectively. Conclusion: The shear bond strength of Conventional etching primer + adhesive was significantly higher than the shear bond strength of self etch primer +adhesive group.

The Active Interface of Ta-Doped Li7La3Zr2O12 for Li Plating/Stripping Revealed by Acid Aqueous Etching

All-solid-state lithium batteries incorporating oxide-based solid electrolytes have attracted much attention as a promising battery system for enabling highly reversible Li metal anodes. However, the cycling stability of Li plating/stripping reactions at higher charging/discharging rates on garnet-type solid-state electrolytes must be improved to realize a practical Li metal anode for solid-state batteries. Here, we report that a short acid etching procedure performed in ambient air significantly activates the Ta-doped Li7La3Zr2O12 (LLZT) surface compared to polishing under inert gas atmosphere such as dry Ar. It has been believed that Li7La3Zr2O12 (LLZ) and related doped LLZ solid electrolyte surfaces need to be mechanically polished in dry Ar before the cell fabrication to remove Li2CO3 and LiOH that are present on the surface. However, a commonly used mechanical polishing procedure is found to form a thin electrochemically inactive layer on the LLZT surface, whereas a short acid etching procedure (e.g., HCl) removes the inactive layer, and the acid-etched LLZT exhibits excellent cycling stability.

Surface characterization of nanostructured commercially pure titanium modified by sandblasting and acid-etching for implant applications

This study investigated the surface characteristics of ultrafine-grain commercially pure titanium (UFG CP-Ti) substrates produced by equal channel angular pressing (ECAP), compared with those of coarse-grain commercially pure titanium (CG CP-Ti) and Ti–6Al–4V (Ti-64) substrates. All Ti surfaces were sandblasted and acid-etched (SLA-treated) to produce micro-rough surfaces. Tensile and microhardness tests were carried out to measure the mechanical properties of fabricated samples. Then the surface characteristics of samples including contact angle measurements, surface morphology and in vitro cell response were evaluated after polishing, sandblasting and acid etching procedures. The results showed that after applying four passes of ECAP, the average grain size of microstructure decreased from 25 µm to 170 nm, while the ultimate tensile strength increased from 545 ± 24 MPa to 971 ± 38 MPa. Investigation of surface morphologies carried out by scanning electron microscopy indicated that ECAP-processed substrate exhibits nano-topography compared with CG CP-Ti and Ti-64 substrates after applying SLA process. In addition, the contact angle of SLA-treated CG CP-Ti and UFG CP-Ti substrates decreased from 68.3° to 9.5° and 51.9° to 7.4°, respectively, indicating a significant improvement of surface wettability. The morphologies of MG63 cells cultured on the developed surfaces proved the potential superior osteoblast cell compatibility of the micro-roughened surface made of UFG CP-Ti substrates over CG CP-Ti and Ti-64 substrates.

Influence of hydrofluoric acid etching time and concentration on shear bond strength of metal brackets to ceramic surfaces

Abstract Introduction Surface treatment prior to bonding ceramic brackets with hydrofluoric acid is indicated because of its ability to promote morphological changes necessary for adhesion. Objective To evaluate the shear bond strength (RUC) of metal brackets bonded to the feldspar ceramic surface under the action of hydrofluoric acid (AF), in different concentrations (5% and 10%) and different application times (30 and 60 seconds). Material and method Four nickel-chrome metal blocks that received an application of feldspathic ceramic were used, to which 80 metal brackets (Abzil/3M) were bonded and divided into 4 Groups (n=20) according to the acid etching procedure. The blocks were etched with 5% hydrofluoric acid for 30 and 60 seconds (AF5/30 and AF5/60, respectively) and 10% hydrofluoric acid for 30 and 60 seconds (AF10/30, AF10/60, respectively). The resin composite used was Transbond XT (3M) and the presence of a glazer was maintained on the ceramic surface. The specimens were placed on a Universal test machine Instron 4411 (Instron Corp, USA) to which a chisel was adapted to perform the shear test at a speed of 1mm/min. The data were submitted to the analysis of variance (ANOVA) and the Adhesive Remnant Index was evaluated. Result In the time interval of 30 seconds, there was no significant difference for the 5% and 10% hydrofluoric acid concentrations. In the 60-second time interval, the 10% concentration showed significantly higher shear bond strength values (p&lt;0.05). The ARI showed predominance of scores 1 and 2. Conclusion It was concluded that 10% hydrofluoric acid showed higher shear bond strength values in 60 seconds of etching, while 5% hydrofluoric acid showed no significant difference between the etching times.

Shear Bond Strength of Orthodontic Brackets Luted with RMGIC After Er:YAG Laser Etching with Two Pulse Modes Using a Digitally Controlled “X-Runner” Handpiece

To compare the shear bond strength (SBS) values of orthodontic brackets luted using a resin-modified glass ionomer cement (RMGIC) on enamel surfaces etched using either an Er:YAG laser in two different working modes, or a conventional etching protocol, including phosphoric acid. Sixty healthy human premolars were randomly allocated to three experimental groups (n = 20) and etched with: Group 1: Er:YAG laser in super-short pulse (SSP) mode (100 mJ, 20 Hz, 2 W); Group 2: Er:YAG laser in quantum square pulse mode (120 mJ, 10 Hz, 1.2 W) using a digitally controlled handpiece ("X-Runner"); Group 3 (control): 5.25% sodium hypochlorite pretreatment, then 37% phosphoric acid for 15 sec. Stainless steel brackets were bonded using light-curing RMGIC for orthodontic bonding. After term cycling (1800 cycles), SBS testing was performed using a universal testing machine. After debonding, both enamel and bracket surfaces were examined to determine the amount of RMGIC still present on the surfaces. Group 3 surfaces gave the lowest mean SBS (10.6104 ± 2.66196 MPa), whereas Group 1 provided the highest 1 (13.1795 ± 3.37904 MPa), which was significantly different from the control (Group 3, p = 0.0226). Group 2 provided intermediate values (11.8486 ± 0.59832 MPa) nonsignificantly different from the control or from SSP (p = 0.4215 and p = 0.3082, respectively). Er:YAG laser treatment in SSP mode of enamel surfaces for orthodontic bonding provided higher SBS and a shear behavior of the luting material similar to the conventional acid-etching procedures, making it a viable alternative to acid etching.

Does acid-etching jeopardize dentin bonding durability?

Purpose: The purpose of the study was to evaluate the impact of the etching process on the durability of normal versus sclerotic dentin bonded interfaces.Materials & Methods: Micro-tensile bond strengths and interfacial nanoleakage, within bonded normal or sclerotic dentin interfaces created by Adper Single Bond 2, Optibond XTR, Single Bond Universal, Ketac Molar (glass ionomer) or Photac Fil (resin-modified glass ionomer), were evaluated after 24 h, 6 m and 12 m of water storage. Results: Adper Single Bond 2, Optibond XTR and Single Bond Universal exhibited higher immediate bond strengths and nanoleakage than did Ketac Molar or Photac fil. Normal dentin exhibited higher immediate bond strength and lower immediate nanoleakage when compared to sclerotic dentin, using Adper Single Bond 2, Optibond XTR and Single Bond Universal. Twelve months of water storage resulted in a significant decrease in micro-tensile bond strength in both normal and sclerotic dentin bonded by these three adhesives. However, there was no significance difference between the bond strengths and nanoleakage created by Ketac Molar and Photac Fil, used with normal or sclerotic dentin at the three storage periods. Conclusion: Compared to resin-based etching restoratives, mineral-based non-etching restoratives (Ketac Molar and Photac Fil) provided much more durable bonds, to both normal and sclerotic dentin, over a period of 12 months. It is obvious that the acid-etching procedure is the main cause of instability of resin-dentin bonded interfaces. Sclerotic dentin did not act as a bonding impediment with mineral-based non-etching restoratives as it did with resin-based etching adhesives. Clinical Significance: Although recently introduced adhesive resins have attempted to improve resin-dentin bond durability, biodegradation of resin-dentin bonds over time continues to jeopardize the durability of resin composite restorations.

Evaluation of the effect of moisture and saliva on the shear bond strength of brackets bonded with conventional bonding system and moisture insensitive primer: An in vitro study

Introduction: Bonding of orthodontic attachments with acid etching is the most commonly used orthodontic procedure. However, there are certain limitations with acid etching procedure like/moisture contamination, etching time, the concentration of adhesive, etc., Moisture insensitive primers (MIPs) were introduced to overcome these limitations. Objectives: The aim of this study is to compare the shear bond strength of orthodontic brackets bonded with a MIP (Transbond MIP, 3M Unitek) against a conventional primer (Transbond XT, 3M Unitek) when contaminated with saliva – in vitro study. Methodology: Sixty maxillary premolars extracted for orthodontic purpose or due to periodontal involvement with sound buccal surfaces were collected, cleaned thoroughly, and stored in 0.1% (wt/vol) thymol at room temperature for 2 weeks. Following materials were used: Transbond XT Light cure adhesive (3M unitek), Transbond XT primer (3m unitek), Transbond MIP primer (3M unitek), and Metal brackets (3M unitek). A commercially available artificial saliva (AQWET, CIPLA) was used for contamination purpose. Ivoclarbluephase N LED light curing unit were used for curing purpose. Results: Mean bond strength was well above the clinically acceptable bond strength values indicating the use of these hydrophilic bonding materials in contaminated environments (8.5 Mpa for Transbond XT and 9.25 Mpa for Transbond MIP). On comparison of bond strengths of MIP and XT when contaminated with saliva, statistically significant values were obtained with contamination with saliva after primer application. There was a statistically significant increase in the bond strength after primer application (P = 0.233) and before and after primer application (P = 0.027*). Transbond MIP can be used to achieve adequate bond strength in saliva contaminated condition. Conclusion: Under dry condition, the shear bond strength of conventional primer (TRANSBOND XT) was significantly increased when compared to MIP. Under wet conditions MIP (TRANSBOND MIP) showed the highest shear bond strength and hence can be considered as a material of choice in wet conditions.

The Effect of ortho-Phosphoric Acid Etching Application on Enamel Surface ATR-FTIR and SEM studies

The acid etching procedure represents a procedure that increases the bond strength between the etched enamel and the composite resin. The aim of this study was to evaluate the effect of ortho-phosphoric acid 37% on the morphology and composition of the enamel surface. The surfaces of four extracted teeth (two incisors and two premolars) were etched with 37% ortho-phosphoric acid solution for 15 seconds. The teeth were examined by ATR-FTIR spectroscopy and SEM microscopy in order to determine the degree of the enamel demineralization. A major change on teeth composition and morphology has been found. The results are discussed and compared with those of the effects of different concentrations of bleaching agent (carbamide peroxide) on the enamel surface. Etching with 37% ortho-phosphoric acid caused structural and morphological changes to the dental enamel surfaces.

Nanoporous Carbon Derived from Core-Shells@Sheets through the Template-Activation Method for Effective Adsorption of Dyes.

A novel template-activation method was used to create nanoporous carbon materials derived from core–shells@rGO sheets. The carbon materials were prepared through an acid etching and thermal activation procedure with three-dimensional Fe3O4@C@rGO composites as precursors and Fe3O4 nanoparticles as the structural template. The activation at different temperatures could provide materials with different specific surface areas. The unique nanoporous structures with large surface areas are ideal adsorbents. The nanoporous carbon materials were used as adsorbents for the removal of rhodamine B (Rh-B). C@rGO-650 illustrated better adsorption performance than the other synthesized adsorbents. It displayed good recyclability, and its highest adsorption capacity reached up to 14.8 L·g–1. The remarkable adsorption properties make nanoporous carbon a useful candidate for wastewater treatment. This template-activation method can also broaden the potential applications of core–shells@sheet structures for the construction of nanoporous carbon, which helps to resolve the related energy and environmental issues.