The Effect of Brilliant Blue-Based Plaque-Staining Agents on Aesthetic Orthodontic Appliances

Orthodontic appliances discolour over treatment time, and a yellowish plaque builds up on the contact area of the brackets, adhesive and teeth. Brilliant Blue-based plaque-staining agents (BBPSAs), which increase tooth brushing efficiency, have the potential to support the maintenance of proper oral hygiene during orthodontic treatment. However, they exhibit strong colouring properties, and their impact on the aesthetics of braces remains unclear. Therefore, the aim of this study was to investigate the influence of commercially available BBPSAs on the colour of aesthetic orthodontic materials. A light-cured, colour-changing orthodontic adhesive and new-generation, monocrystalline, sapphire brackets were chosen for the experiments. The effect of the staining agent on the tested materials was investigated in terms of the reaction temperature and time, as well as the presence of black tea-induced impurities on the materials. The CIELAB (Commission Internationale de L’éclairage L* a* b*) colour system parameters were measured, and the colour differences (ΔE*ab and ΔE00—the Commission Internationale de L’éclairage 2000 colour-difference) were determined for the materials under several experimental conditions. The braces’ green-red colour expression was positively affected by the BBPSA. Under in vitro conditions, the regular use of the BBPSA for 90 days visibly improved the unfavourable colour change caused by the black tea.

Orthodontic materials with fluoride have an antimicrobial ability for the prevention of white spot lesions

Aim: Orthodontic brackets during their wear cause demineralization of enamel, which is the initial step in caries development. The prevention of such spots is crucial to ensure healthy teeth, but patients’ compliance is not the most optimal way. The aim of this study was to compare the antimicrobial properties of fluoride-containing orthodontic materials to the materials without additional fluoride. Materials and Methods: Antibacterial effectiveness of orthodontic materials with fluoride – Transbond Plus SEP Bonding agent, Transpond Plus Adhesive agent, Fuji I Band cement, Fuji Ortho LC Adhesive agent, Ortho Solo Bonding agent, and without antimicrobial substances – Transpond XT Bonding agent, Transbond XT Primer were tested with the inhibition on most common causes L. achidophilus (ATCC 4356) and S. mutans (ATCC 10449) and compared to negative control. Antimicrobial effectiveness of each material was measured with the agar diffusion method and expressed with the diameters of inhibition zones around the disk. Results: Materials containing fluoride showed more antimicrobial effectiveness compared to materials without fluoride or negative control (p<0.001), respectively. Materials from the group with no antibacterial substances were not statistically different compared to the negative control (P>0.05). Conclusion: Materials containing fluoride showed more significant antimicrobial effectiveness when compared to the materials without antimicrobial substance and thus might have the potential of antimicrobial properties in vivo.

Biosafety of Nanoparticles Used in Orthodontics - A Literature Review

Nanotechnology is the science of manipulating matter, measured in the billionths of a nanometer, roughly the size of two or three atoms. It is widely used in our day-today life including its use in medicine and is considered as a vital current technology of the 21st century based on its economic and scientific potential. Its application is being experimented in various domains in orthodontics, from surface coatings to the development of novel materials. Orthodontic materials must have specific characteristics such as biological safety, functionality, and adequate tissue response. They have to pass specific biocompatibility tests to meet regulatory standards. Any material used in oral cavity might encourage unnecessary disturbance due to its complex and varied environment. The nanomaterials have many advantages in the field of orthodontics, especially with improved mechanical and antimicrobial properties. Nanoparticles can easily penetrate tissues and can affect biological behaviours at different levels. The introduction of nanotechnology gives better opportunities to both patient and orthodontist to new physicochemical, mechanical, and antibacterial properties of nanosized materials and can be used in coating orthodontic wires, elastomeric ligatures, and brackets, producing shape memory polymers and orthodontic bonding materials. The present review article focuses on the application of nanoparticles in orthodontics. This article presents a brief overview of nanotechnology, types of nanoparticles, biological safety of different nanoparticles used in orthodontics and their applications in the field of dentistry and orthodontics. KEY WORDS Nanoparticles, Biocompatibility, Orthodontics, Nanoscience

In Vitro Evaluation of Structural Factors Favouring Bacterial Adhesion on Orthodontic Adhesive Resins

Bacterial adhesion to the surface of orthodontic materials is an important step in the formation and proliferation of plaque bacteria, which is responsible for enamel demineralization and periodontium pathologies. With the intent of investigating if adhesive resins used for bracket bonding are prone to bacteria colonization, the surface roughness of these materials has been analyzed, combining information with a novel methodology to observe the internal structures of orthodontic composites. Scanning electron microscopy, combined with focus ion bean micromachining and stylus profilometry analyses, were performed to evaluate the compositional factors that can influence specific pivotal properties facilitating the adhesion of bacteria to the surface, such as surface roughness and robustness of three orthodontic adhesive composite resins. To confirm these findings, contact angle measurements and bacteria incubation on resin slide have been performed, evaluating similarities and differences in the final achievement. In particular, the morphological features that determine an increase in the resins surface wettability and influence the bacterial adhesion are the subject of speculation. Finally, the focused ion beam technique has been proposed as a valuable tool to combine information coming from surface roughness with specific the internal structures of the polymers.

Elution study of acrylic monomers from orthodontic materials using high performance liquid chromatography (HPLC)

Purpose Main goal of the study was the identification and quantitative analysis of monomer elution from materials commonly used in fixed orthodontic therapy. Studies have shown severe health effects of monomers including cytotoxic, allergenic or mutagenic potential and endocrine changes. This in vitro study focusses primarily on five resins which are usually processed intraorally and remain in the oral cavity long-term. Methods We tested the elution of monomers from specimens (7.5 mm × 1.5 mm) immersed in artificial saliva at body temperature (37 °C) for 30 min to 5 weeks. The used method is in accordance with DIN EN ISO 10993-13. The five tested materials were BrackFix® (Voco GmbH, Cuxhaven, Germany), Triad®Gel (DeguDent GmbH, Hanau, Germany), and Transbond™ XT, LR and Plus (3M Unitek, Monrovia, CA, USA). All aliquots were analyzed using high performance liquid chromatography (HPLC). Data were statistically analyzed. Results All five analyzed materials eluted substances over a period of 5 weeks. Identified substances included bisphenol A (BPA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA). BPA eluted from Transbond™ Plus, XT, LR and BrackFix®. The cumulated mean values after 35 days ranged from 16.04 to 64.83 ppm, depending on the material. TEGDMA eluted with a mean of 688.61 ppm from Transbond™ LR. UDMA with a mean of 1682.00 ppm from Triad®Gel. For each material the highest concentrations of all these substances were found in the first elution period. Other substances that were not equivocally identified or of low concentration also eluted. Conclusion Using the described method, it is possible to qualitatively and quantitatively determine the in vitro elution of monomers from orthodontic materials. The concentrations of the substances identified were below the current maximum recommended intake. However, a cumulative effect and low-dose effects should be considered for both patients and dental professionals, especially for young patients. Measures to reduce exposure patients and practitioners are suggested.

Metallic Orthodontic Materials Induce Gene Expression and Protein Synthesis of Metallothioneins

Background: Due to the long-term contact with metallic elements of orthodontic appliances, the potential influence of released metal ions on living organisms and the type of induced changes was investigated. Materials and Methods: Twenty-four young domestic pigs classified in two groups (experimental and control) were chosen as the object of this study. In the experimental group of animals, two metal plates consisting of orthodontic bands representing the mass of orthodontic appliance were mounted on the internal side of the cheek for six months. The liver, lung, and brain samples were taken post mortem from animals of both groups. The gene expression of two isoforms of metallothionein (MT-1 and MT-2) were investigated using the qPCR technique. Protein expression was confirmed by the Western blot and ELISA techniques. Results: The differences in metallothionein concentrations were observed in the lung and brain in the the group of experimental animals, but not in the liver. The expression of MT-1 and MT-2 genes in the experimental vs. control group (respectively) was as follows: lung MT-1 1.04 vs. 1.11, MT-2 0.96 vs. 1.05, liver MT-1 0.89 vs. 0.91 vs. 1.12, MT-2 0.91 vs. 1.05, brain MT-1 1.24 vs. 1.20, and MT-2 0.955 vs. 0.945. These results were confirmed by gene activity, which was tested by qPCR. This increased the activity of metallothionein genes in the lungs and brain as a consequence of the release of metal ions into these tissues. The possible effects of detected change in metallothionein-2 gene expression could be the alteration of physiological functions of lung tissue. Conclusions: The effect of long-term exposure to metal orthodontic appliances on metallothioneins gene expression, as well as the induction of protein synthesis was proved.

Highly efficient antibiofilm and antifungal activity of green propolis against Candida species in dentistry materials

This study evaluated the effect of green propolis extract on the adhesion and biofilm formation of Candida species in dentistry materials. Phytochemical analysis of green propolis extract was performed by high-performance liquid chromatography. Adhesion was quantified by counting the number of yeast cells adherent to dental material fragments in a Neubauer chamber. Biofilm formation was determined by counting colony-forming units recovered from dental material fragments. The intensity of biofilm adhesion was classified as negative, weak, moderate, strong, or very strong. Fifteen compounds, mainly flavonoids, were identified in green propolis extract. All strains adhered to and formed biofilms on the surfaces of the orthodontic materials studied. On steel and resin, yeast cell adhesion intensities were weak at all incubation times, except for those of Candida parapsilosis and C. tropicalis, which were moderate at 12 h. At 24 and 48 h, C. albicans formed biofilms on steel with moderate adhesion affinities; at 24 and 48 h, C. parapsilosis formed biofilms with very strong affinities. C. tropicalis formed biofilms with strong and very strong affinities at 24 and 48 h, respectively. On resin, all species displayed strong affinity for biofilm formation at 24 and 48 h, except for C. tropicalis, which displayed very strong affinity at only 48 h. Green propolis extract displayed antifungal activity and inhibited both adhesion and biofilm formation at 2.5 μg/mL. This study reinforces the idea that green propolis has antifungal activity and interferes with the virulence of Candida species.

Surface Roughness on the Slots and Wings of Various Ceramic Self-Ligating Brackets and their Potential Concern on Biofilm Formation

Objective: The surface roughness of various orthodontic materials could affect biofilm formation and friction. The purpose of this study was to examine the surface roughness and chemical composition of the slots and wings of several ceramic self-ligating brackets. Study design: Four types of ceramic self-ligating brackets were separated into experimental groups (DC, EC, IC, and QK) while a metal self-ligating bracket (EM) was used as the control group. Atomic force microscopy and energy-dispersive x-ray spectroscope were used to examine the surface roughness and chemical composition of each bracket slot and wing. Results: The control group was made of ferrum and chrome while all the experimental groups were comprised of aluminum and oxide. There was a statistically significant difference in the roughness average (Sa) among the various self-ligating brackets (p< 0.001 in slots and p<0.01 in the wing). The slots in the EC group had the lowest Sa, followed by the DC, IC, control, and QK groups. The wings in the IC group had the lowest Sa, followed by the EC, DC, control, and QK groups. Conclusions: There is a significant difference in the surface roughness of the slots and wings among several types of ceramic self-ligating brackets.