Adhesively-bonded joints are widely used to join structural components. The most common joint types are single-lap joints (SLJ), double-lap joints (DLJ), stepped-lap joints and scarf joints. Several factors influence the behaviour and strength of an adhesive joint, namely the type of adhesive (brittle or ductile, strong or weak) and joint geometry. One of the most important parameters that affects the joint strength is the overlap length (LO). A comparative study that involves several joint geometries and uses adhesives with different characteristics was carried out to check which type of adhesive is most suitable for a particular joint geometry. For this purpose, SLJ, DLJ, stepped-lap joints and scarf joints were chosen for testing with three adhesives. The experimental results were compared with numerical results obtained from Abaqus® using an integrated cohesive zone modelling module. Initially, a stress analysis was carried out to compare the different joint geometries. With this work, it was concluded that the optimal joint type significantly depends on the type of adhesive used, such that less strong and ductile adhesives are more suitable for joint geometries that exhibit large stress variations, while stronger but more brittle adhesives are recommended for joint geometries with more uniform stresses.

It would not be an exaggeration to say that adhesive joints have been an essential part of the construction industry for several decades now. However, a substantial disadvantage of bonded joints are the very strict requirements for adherence to the technological procedures defined by the manufacturers of assembly systems. Even a slight deviation from the recommended application steps can have a significant effect on the integrity of the entire system. In the research, five of the most common types of failure to comply with technological procedures in the realization of facade cladding were selected. The aim of the research project was to determine the extent to which a failure to adhere to technological procedures during facade construction can influence the effectiveness of the bonded joint. In construction practice, it is quite common during the implementation of a project that there are failures to comply with multiple requirements, or deviations from the prescribed procedures. For this reason, not only individual types of failure to comply with technological procedures were tested, but also their combinations. Altogether, 31 combinations of selected types of failure to comply with technological procedures were tested on one type of cladding. The adhesive joint was tested for shear strength and the adhesion of the adhesive to the substrate on a total of 352 samples. The results of the tests clearly confirm the hypothesis that failure to comply with technological procedures has a significant effect on the effectiveness of bonded joints. It is mainly the different combinations of failure to comply with technological procedures where the bonded joint loses effectiveness in the order of tens of percentage points.

This study aimed to identify diagnosis and restorative practices of non-carious cervical lesions (NCCLs) by a group of Brazilian dentists from the State of Rio de Janeiro. After ethical approval, a questionnaire was sent for a group of dentists registered at the Regional Council of Dentistry of the State of Rio de Janeiro (CRO-RJ, Brazil) and the answers were collected in a period of 15 days. The questionnaire considered training experience and attendance profile, diagnostic attitudes and restorative practices for direct restorations of NCCLs. The data were presented in a descriptive way and Chi-square tests (95% significance) were used to verify possible relations between dentists training/attendance profiles and NCCLs diagnosis/restorative attitudes. Most part of dentists considered the etiology as multifactorial and seek to distinguish the different types of NCCL, but only a minority respond to use auxiliary methods for diagnosis. Cotton-roll is the most used method for moisture control and 51.6% do not use gingival retraction/separation techniques. Two-step total-etch adhesive systems and hybrid/microhybrid composite resins were the most commonly refereed materials for direct restorations. Only 8.3% considered that restorations can last for a period of more than 5 years in clinical service. There was significant relation between remuneration and the type of isolation (p = 0.038) and also with gingival retraction/separation techniques (p = 0.043). It can be concluded that (a) the majority of the respondents revealed to seek distinguishes among the different types of NCCLs, but only a minority use auxiliary methods to diagnosis; (b) the form of remuneration influence the attitudes regarding the isolation method; (c) the two-step total-etch adhesive systems are the most used to restore NCCLs, (d) and that for the most part of the respondents the restorations of NCCLs made with resin composites do not last for more than 5 years.

Bonding of automotive glass is generally performed with 1C PUR adhesive on a primed ceramic frit or naked glass surface. The aim of this research was to replace the chemistry of the primer with an atmospheric pressure plasma treatment (APPT) with compressed air for cleaning and activation directly before bonding. Characterization of the glass surface was performed with surface energy through contact angle, XPS, TOF-SIMS and adhesive peel bead test. The results show that APPT treatment can clean the surface, improve the wetting, improve the bonding but reduce the number of non bridging oxygen for the adhesive to bond to. The highest measured spot temperature of the glass during APPT was measured up to 270 °C, but the temperature was depending on process parameters. A reduction in non bridging oxygen was also seen during heating of the reference glass at 100 °C. A further reaction was seen when measured after a 550 °C heating. A modified APPT treatment with deionized water as precursor was used. The results show that the APPT with water does not lower the level of non bridging oxygen and the bonding was further improved.

The aim of this study is to evaluate the degree of conversion of light-cured resin cement subjected to activation through the interposition of lithium disilicate ceramic produced according to two manufacturing techniques. Cylindrical specimens of RelyX™ Veneer resin cement were generated based on each manufacturing technique (CAD/CAM—computer aided design/computer assisted manufacturing, n = 5 or pressed ceramic technique, n = 5). Next, the specimens were washed in distilled water, dried with absorbent paper and stored in containers filled with distilled water at 37 °C for 24 h. Specimens from each group were subjected to attenuated total reflectance Fourier transform infrared (ATR-FTIR) in order to evaluate their degree of conversion. Data about the degree of conversion (%) were subjected to analysis of variance and to Student’s t-test (α = 0.05%). The degree of conversion of RelyX™ Veneer was statistically higher in the CAD/CAM manufacturing technique (39.83 ± 0.35%) than in the Press one (37.59 ± 0.62%). The light-cured resin cement activated through ceramic structure reinforced with lithium disilicate generated through the CAD/CAM manufacturing technique showed higher degree of conversion than the one generated through the Press manufacturing technique.

The optimization of mechanical properties of adhesive bonds is of interest especially in structural applications. Besides transferring stresses, bondlines can also provide additional functionality, such as measuring deformations in structural timber applications by electrically conductive adhesives. This study investigates the influence of a thermal postcure treatment of polyurethane bonded wood joints. Bonded beech wooden samples were manufactured with three adhesives—a commercial one-component polyurethane for structural laminated timber and two modified ones, filled with electrically conductive particles. Adhesive bonds were subjected to a subsequent postcuring at 80 and 95 °C for 1 and 48 h, respectively. Mechanical properties of the bonds were studied on the macroscopic level by tensile shear tests and the properties of the cured adhesive on the microscopic level by nanoindentation. As a result, the tensile shear strength slightly dropped with addition of filler, while all specimens still fulfilled the requirement of EN 302-1 in dry condition. Nanoindentation revealed minor decreases in mechanical properties of the cured adhesive with postcuring time for two adhesives and a different reaction of carbon black filled polyurethane, as the creep factor decreases with the thermal postcure.

Quality assured surface pre-treatment may greatly enhance adhesive interactions and, thus, the performance and durability of material joints. This holds true as well for substrates used in coating processes as for adherents introduced into bonding processes. Wettable polymeric wetting agents—shortly called polymeric interfactants—contribute to modifying surfaces and governing the properties of interphases. This is demonstrated for amphiphilic polymers directing the adsorption of graphene oxide (GO) nano-sheets from aqueous dispersion on alumina surfaces. In this contribution, contact angle measurements as well as X-ray photoelectron spectroscopy and scanning force microscopy investigations are applied for the characterization of thin films. GO is adsorbed either from a buffered dispersion on pristine aluminum oxide surfaces or on alumina modified with a few nanometers thin layer of a polymeric interfactant. Laterally extended nanoparticles and GO nano-sheets are preferentially found on interfactant layers whereas on pristine aluminum oxide smaller adsorbates dominate. The driving forces directing the GO attachment are discussed using a phenomenological model based on polymer/substrate interactions governing the sticking probabilities of GO nano-sheets with different sizes.

Gecko’s foot hairs exhibit significant frictional anisotropy that enables a strong foot grip in a specific direction and an easy detachment in the opposite direction. In this study, we fabricate adhesive devices with frictional anisotropy mimicking gecko’s foot hair based on oblique micro-beam arrays. The devices adhesion force is strongly anisotropic along the beam tilting direction and depends on the stress distribution at the contact area which, in turn, is affected by the geometry of the beam tips. This dependence is investigated by fabricating and testing micro beam arrays with various tip shapes.

Adhesively bonded joints are being widely used in the fabrication process of aircraft and automobile structures. Surface roughness is an important parameter of product quality that strongly affects the performance of mechanical parts, as wel as production costs. This parameter highly influences the mechanical properties overall of such structures. The effects of UV radiation on the single lap joints manufactured with different types of surface preparation and temperature were examined before and after UV exposure. Sandblasting, sanding and chemical cleaning were used as surface preparation and two test temperatures were used for investigation, 25 and 115 °C. The results of those tests showed that surface preparation highly influences shear strength, but does not affect the stiffness of the tested joints. Temperature also influences the shear strength and stiffness. UV radiation contributes to increase shear strength and do not degrade the tested single lap joints.

To develop an adhesion system satisfying both constant adhesion strength during use and quick debonding ability during a dismantling process. Adhesive properties were investigated for the random and block copolymers consisting of 1-isobutoxyethyl acrylate (iBEA), 2-ethylhexyl acrylate (2EHA), and 2-hydroxyethyl acrylate (HEA) as the dismantlable pressure-sensitive adhesives in the presence of a photoacid generator in response to dual external stimuli of photoirradiation and post baking. The use of LED combined with a new photoacid generator SIN-11 was enable us to achieve a rapid dismantling process during UV irradiation within several minutes. The protection of the ester alkyl group in the iBEA repeating unit to give an acrylic acid unit was suppressed by the introduction of isobornyl acrylate (IBoA) as the additional unit into the copolymer of iBEA, 2EHA, and HEA. While IBoA‐containing block copolymer showed a constant adhesive strength during photoirradiation as the single external stimulus, deprotection was immediately induced by the subsequent heating, leading to a significant decrease in the adhesive strength. The copolymer including the iBEA and IBoA units was revealed to function as the highly sensitive adhesive materials for dual-locked dismantlable adhesion.

This paper reports on the adhesion characteristics between microspheres and rubber surfaces. Silica, polystyrene, and poly(methyl methacrylate) microspheres were deposited on cis-1,4-polybutadiene (BR) films. A BR meniscus formed on the sphere surfaces when the film thickness was less than the diameters of the spheres. Additionally, the attractive forces acting on the spheres in the direction of the BR films were examined via atomic force microscopy. Sedimentation of the spheres occurred for films with thicknesses much greater than the diameters of the microspheres in all systems. Interestingly, this wetting process occurred even in the silica/BR system, despite the incompatibility of these materials. The driving force for meniscus formation is the difference between the surface free energy of BR (γ BR) and that of the spheres (γ sphere). For all systems, γ BR is lower than γ sphere, i.e., the BR surface is more stable than those of the spheres, and thus a meniscus forms to stabilize the system. Once a meniscus formed, a downward force acted on the spheres to embed them into the BR film. Sedimentation eventually ceased when the angle between the tangential line of the sphere and the rubber surface became equal to the equilibrium contact angle determined by Young’s equation. Interestingly, the sedimentation behavior was nearly identical for spheres with various surface free energy values except in terms of their final positions. The same sedimentation phenomena were studied with crosslinked BR films. In contrast to the experiments performed using various types of spheres, the sedimentation behavior varied with different rubber characteristics. The results of these studies indicate that the sedimentation behavior mainly depends on the physical properties of the rubbers used, although the physical properties of the spheres are in determining their final depth.

Adhesion hysteresis was investigated with the energy dissipation in the contact experiments between a spherical glass lens and a polydimethylsiloxane (PDMS) block. The experiments were conducted under step-by-step loading–unloading for the spontaneous energy dissipation. The force, contact radius, and displacement were measured simultaneously and the elasticity of the PDMS was confirmed. The work of adhesion was estimated in the loading process of the strain energy release rate. The total energy dissipation has been observed to be linearly proportional to the contact radius in the unloading process. The approximately constant gradient of the energy dissipation for each unloading process has been found. The result would provide how the dissipation is induced during the unloading as some interfacial phenomena. The fact has been discussed with some interfacial phenomena, e.g., the adsorbates on the surface, for the mechanism of adhesion hysteresis.

The objective of this study was to evaluate the coumarin-based iodonium hexafluoroantimonate (P3C-Sb) in the polymerization kinetics of an experimental model adhesive resin both in presence of solvent and acid monomer content. A monomer mixture based on Bis-GMA, TEGDMA and HEMA was used as a model adhesive resin. Initially a screening was performed to evaluate P3C-Sb concentrations (0.25, 0.50, 1, 2, 4 mol%). Four photoinitiator systems using P3C-Sb at 2 mol% were evaluated: CQ + EDAB (control), P3C-Sb + CQ, P3C-Sb + EDAB and P3C-Sb + EDAB + CQ. Additionally, the performance of the photoinitiator systems in the presence of ethanol and acidic monomer at four different concentrations (0, 10, 20, 40 wt%) were evaluated. Real-time Fourier transform infrared spectroscopy was used to evaluate degree of conversion (DC) and rate of polymerization (RP). The ternary initiation system P3C-Sb + CQ + EDAB showed similar DC and RP to CQ + EDAB into the model adhesive resin without ethanol, however, in the presence of solvent, P3C-Sb + CQ + EDAB showed the highest polymerization kinetics. An inhibitory polymerization effect was observed when a solvent was introduced to adhesive resin using CQ + EDAB. Polymerization reaction was affected by the presence of acidic monomer irrespective of initiation system used. Adhesive resins with CQ + EDAB and P3C-Sb + CQ + EDAB as initiation systems showed similar DC to CQ + EDAB in presence of acidic monomer. The use of P3C-Sb as a third component of the initiation system seems to be an interesting alternative to improve the polymerization kinetics of simplified dental adhesives which showed to be less sensitive to the residual presence of solvent before photoactivation and it was similar polymerization behavior to CQ + EDAB in presence of acidic monomer.

An experimental investigation was performed to study the effect of surface roughness and oxidation on the shear strength of single-lap-joints of AA6061, AA7075 aluminum alloys and an AISI 1080 steel alloy bonded with two different epoxy adhesives. An optimum surface roughness that provided the maximum shear strength was obtained for all the alloys at room temperature. The variation of the shear stress due to the different heat treatment temperatures revealed that the oxides developed on the alloy surfaces adversely affected the adhesive shear strength. The bulk concentration of magnesium of the aluminum alloys were also observed to affect the adhesive shear strength of the joints.

Adhesive bonding shows a high potential to join carbon fiber reinforced plastics (CFRP), if the adhesion between adhesive and part surface is verified. Unfortunately, this adhesion is often reduced in case of the mold-based part production and its unavoidable application of release agents. Due to the resulting presence of release agent residues on the surface of the cured CFRP-parts the adhesion is lowered. To increase the bondability and correlating production efficiency, the amount of release agent transfer should be as small as possible, to reduce the effort in terms of bonding pre-treatment. To achieve this goal, a theoretical, qualitative model about the influence of the relevant processing parameters for a thermoset CFRP-production was developed focusing the (diffusion-based) transfer reduction based on an adapted processing. Indicating the time in which the diffusion is possible, as the main criteria.

Composite materials are already being used in the mass production of structural components in the automotive industry, particularly at the BMW Group. Adhesive bonding is generally considered to be the best technique for joining CFRP (carbon fiber reinforced plastic) light-weight structures. The conventional NDT (nondestructive testing) methods currently being used focus on the detection of material defects, e.g. debonding. These methods give little information about the surface properties or bond quality. A new ENDT (extended nondestructive testing) method is the BonNDTinspect system, based on a patent held by the Fraunhofer IFAM. An ultrasonic atomizer nozzle creates a water-aerosol and the small water droplets are sprayed onto the surface. Depending on the surface properties (surface energy or contamination state), the aerosol will form wide or narrow drops on the surface. We determined a test for certain contaminations, including release agents, oil, and fingerprints, the detection of which is critical to ensure the performance of adhesively joined CFRP structures. The BonNDTinspect system is an inline-capable NDT technique that is suitable for distinguishing surface states for adhesive bonding of CFRP. We verify this statement with destructive tests, including the single-lap shear test. It was found by using an extension of the evaluation criteria that it is possible to detect contamination such as water-soluble release agent, CFRP dust and fingerprints. The investigated contamination with hydraulic oil allows only a clear differentiation between cleaned and contaminated. A contamination with corundum is not detectable by the BonNDTinspect system alone.

Since adhesive bonding becomes a popular and important technique for industry, much research has been conducted by many researchers even in the Asian region. The Asian Conference on Adhesion was established to meet the demand for communication, corroboration, and exchanging information among researchers on adhesion and adhesion related phenomena in the Asian region in 2005.The science committee of this conference consists of members from adhesion societies of Asian countries including China, Korea, and Japan. The first Asian conference took place in Jeju, South Korea, 2005, the second in Beijing, China, 2007, the third in Hamamatsu, Japan, 2009, the fourth in Pusan, South Korea, 2011, and the fifth in Beijing, China, 2013.This Special Issue of Applied Adhesion Science was conceived with the aim of offering to the interested readers an overview of the present research trends presented in the 6th Asian Conference on Adhesion, which took place at Tokyo Institute of Technology in Japan in June 2016. It gathers a collection of seven selected papers, written for this occasion by members of academia who joined the conference and made presentations.Asia is a region whose economy has been increasing quickly, and the industrial power is expanding over the world. The success is supported by the steady efforts of many researchers. In the Asian region, much research on adhesion has intensively been carried out. However, the results seem being not known worldwide. Therefore, this special issue also plays a role in introducing research on adhesion in the Asian region to the world.We really appreciate the efforts by the authors who contributed to the special issue because we did not have a plenty of time to prepare, review, and edit the special issue. Everything has been done within a short period.We also thank the reviewers for their precious critical evaluations of the manuscripts.Finally, we greatly appreciate the kindness of Prof. Silvio de Barros, Editor-in-Chief of Applied Adhesion Science. He has made this special issue possible, and given his advice and guidance during the work.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.AffiliationsDepartment of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo, JapanToshiaki OugizawaDepartment of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, JapanAkio TakemuraResearch Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, JapanChiaki SatoAuthorsToshiaki OugizawaView author publicationsYou can also search for this author in PubMed Google ScholarAkio TakemuraView author publicationsYou can also search for this author in PubMed Google ScholarChiaki SatoView author publicationsYou can also search for this author in PubMed Google ScholarCorresponding authorCorrespondence to Chiaki Sato. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Reprints and PermissionsCite this articleOugizawa, T., Takemura, A. & Sato, C. Editorial for the special issue for the 6th Asian Conference on Adhesion. Appl Adhes Sci 5, 13 (2017). http://doi.org/10.1186/s40563-017-0092-xDownload citationReceived: 05 June 2017Accepted: 29 June 2017Published: 06 July 2017DOI: http://doi.org/10.1186/s40563-017-0092-x

This special issue of Applied Adhesion Science (AAS) contains selected papers presented at the 3rd Luso-Brazilian Conference on Adhesion and Adhesives (CLBA 2016) held in Rio de Janeiro, Brazil, during January 25–27, 2016. CLBA 2016 was chaired by both of us and was co-organized by the Brazilian Association of Adhesion and Adhesives (ABAA) and the Portuguese Association of Adhesion and Adhesives (APAA). The goal of the conference was to join the Portuguese and Brazilian communities to discuss issues related to adhesive bonding research lately developed in both countries. Approximately 60 papers were presented by researchers from many universities and research centers. In order to disseminate the work presented at CLBA 2016, selected papers were prepared which resulted in the present Special Issue.Four papers deal with adhesive dentistry aspects. They were presented by colleagues from the Brazilian dental materials community. Lopes et al. evaluated the influence of the previous use of eugenol based materials to a permanent restoration on the marginal microleakage. They also investigated the influence of mechanical cleansing associated with chemical cleansing with chlorhexidine gel. It was found that eugenol, when associated with endodontic or temporary restorative material, has no influence on the microleakage of the definitive composite resin restoration. The study presented by Da Silva et al. evaluated the shear bond strength of three different composite resins to fiber posts surfaces. The influence the adhesive used as pretreatment was also investigated. The authors concluded that the use of silorane based composite resins to customize posts requires the use of adhesive as surface pretreatment. Schwertner et al. evaluated the effect of green tea on the shear bond strength of metal orthodontic brackets to human enamel after home whitening treatment. They concluded that green tea is an alternative treatment to allow bracket bonding immediately after home whitening treatment. Another study on the shear bond strength of brackets to enamel was presented by Guiraldo et al. The objective of the study was to evaluate the enamel roughness and shear bond strength of dental composite after removal of metal brackets bonded with different adhesives. The shear bond test results shown that the 4 adhesives produced adequate bond strength, however the enamel did not return to the initial conditions.Two papers focus on the use of castor oil polyurethane as adhesive applied to different substrates. Pareira et al. performed shear tests using MDF substrates. They concluded that the polyurethane derived from castor oil can be used to bind MDF panels. The results show its superior shear average resistance compared to a synthetic adhesive. Mölleken et al. evaluated the pressing time in the production of Pinus taeda edge glued panels (EGP). According to their results the optimal pressing time for the panels production is 4 h.The review process gave a deeper insight into the last developments in adhesion in Brazil and Portugal and the chance to discuss in detail the manuscripts directly with the authors. We would like to thank the authors for their patience with the process and the reviewers for providing critical evaluations of these manuscripts. This special issue was sponsored by the Brazilian Federal Agency for the Support and Evaluation of Graduate Education (CAPES).Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.AffiliationsDepartamento de Engenharia Mecânica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, PortugalLucas F. M. da SilvaDepartment of Mechanical Engineering, Federal Center of Technological Education (CEFET/RJ), Av. Maracanã 229, Rio de Janeiro, RJ, 20271-110, BrazilSilvio de BarrosAuthorsLucas F. M. da SilvaView author publicationsYou can also search for this author in PubMed Google ScholarSilvio de BarrosView author publicationsYou can also search for this author in PubMed Google ScholarCorresponding authorCorrespondence to Lucas F. M. da Silva. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Reprints and PermissionsCite this articleda Silva, L.F.M., de Barros, S. Editorial TS: Papers from the 3rd Luso-Brazilian Conference on Adhesion and Adhesives (CLBA2016), Rio de Janeiro, Brazil, 25–27 January 2016. Appl Adhes Sci 5, 12 (2017). http://doi.org/10.1186/s40563-017-0090-zDownload citationReceived: 06 June 2017Accepted: 15 June 2017Published: 23 June 2017DOI: http://doi.org/10.1186/s40563-017-0090-z

The 52nd annual meeting of the Brazilian Dental Materials Group, known by its acronym in Portuguese GBMD (Grupo Brasileiro de Materiais Dentários), was held in Uberlândia, Minas Gerais state, Brazil between July 19–22, 2016. The conference was chaired by the School of Dentistry from Federal University of Uberlândia. In total, 9 researchers lectured, 258 research posters were presented, and above 350 attendees participated in the meeting. The conference addressed significant issues related to dental biomaterials, including tools used for in vitro investigation and the clinical applicability of dental materials and techniques. Several researchers, including many undergraduate students, had the opportunity to share and discuss their research findings with the GBMD community and with experienced investigators.The oral speakers presented the following lectures during the meeting: “CAD-CAM restorations: scientific evidence and clinical performance” by Prof. Flávio Neves (UFU); “Strategies to stabilize the resin-dentin bonds” by Prof. Josimeri Hebling (UNESP-Araraquara); “Anatomy of root canals and evaluation of endodontic materials” by Prof. Manoel Sousa Neto (USP-Ribeirão Preto); “Laboratory testing of dental adhesives and its clinical relevance” by Prof. Steve Armstrong (University of Iowa College of Dentistry, USA); “Technology applied to the scientific investigation of dental materials” by Prof. Marcelo Giannini (UNICAMP-Piracicaba); “Longevity of dental restorations in anterior and posterior teeth” by Prof. Flávio Demarco (UFPel); “Use of thio-urethane additives to reduce polymerization shrinkage and improve conversion in composites” by Prof. André Faria e Silva (UFS); “Improving light-curing instruction in dental school” by Prof. Richard Price (School of Biomedical Engineering, Dalhousie University, Canada); and “Fractography studies applied to restorative materials” by Prof. Paulo Cesar (USP-São Paulo).This special issue of Applied Adhesion Science contains peer-reviewed papers submitted through the journal online submission system. The articles address relevant issues concerning the adhesive dentistry, including methods to age the bonded dentin interfaces, novel polymerization promoters for dental adhesives, and bonding to dental ceramics and root canal walls. This issue is the Fourth Special Issue with papers selected from GBMD meetings published in Applied Adhesion Science. I am delighted to share that the journal has been recently accepted for inclusion in the Scopus database, which hopefully will increase the readership of the journal and aid in consolidating the name of the journal as well as of the GBMD in the international research community. The organizing committee of the 52nd GBMD meeting thanks the sponsors and all colleagues who helped to organize the conference. We also thank to the researchers who served as reviewers for the articles published in this Special Issue. Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.AffiliationsSchool of Dentistry, Federal University of Pelotas, Rua Gonçalves Chaves 457, room 505, Pelotas, RS, 96015-560, BrazilRafael R. MoraesAuthorsRafael R. MoraesView author publicationsYou can also search for this author in PubMed Google ScholarCorresponding authorCorrespondence to Rafael R. Moraes. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Reprints and PermissionsCite this articleMoraes, R.R. Editorial: 52nd annual meeting of the Brazilian Dental Materials Group. Appl Adhes Sci 5, 11 (2017). http://doi.org/10.1186/s40563-017-0091-yDownload citationReceived: 06 June 2017Accepted: 06 June 2017Published: 09 June 2017DOI: http://doi.org/10.1186/s40563-017-0091-y

Bacterial adherence to restorative materials such as composite resin is one of the aetiology of secondary caries. This study evaluated the antibacterial efficacy of fifth generation bonding agent (BA) modified with nisin, against Streptococcus mutans based on its growth, adherence and membrane integrity. Adhesive eluents of the experimental bonding agents were obtained using 250 μl Brain Heart Infusion (BHI) broth and the groups were control (BA with 0% Nisin), bonding agent with 1 wt% (NBA 1) and 5 wt% nisin (NBA 5). To this, 10 μl S. mutans culture was added and incubated at 37 °C. Bacterial growth was estimated by changes in optical density using spectrophotometer every 20 min for 2 h. The results were statistically analysed using one way ANOVA followed by Tukey Post Hoc test. For adherence and membrane integrity test, 10 μl of BHI supplemented with 1% sucrose and 50 μl of bacterial suspension were inoculated onto the cured specimens, and incubated for 4 h. After rinsing, 1 ml of Live/Dead BacLight bacterial viability stain was added and incubated in the dark for 15 min and observed under confocal laser scanning microscope (CLSM) for intact (green/live) and damaged (red/dead) bacterial membranes. Mean optical density was significantly higher in control group at all time intervals with maximum value at 2 h (0.83 ± 0.008), while there was a concentration dependant reduction in bacterial growth with the NBA groups (0.50 ± 0.007). Correspondingly, the NBA groups showed higher amount of dead than live bacteria, while live bacteria were predominant in the control group. Addition of an antibacterial agent nisin in dentin bonding agent may render the resin dentin interface more resistant to bacterial penetration, and adherence of cariogenic bacteria like S. mutans.