Graphene-Based Coatings for Surface Modification and Their Applications in Fixed Orthodontics: A Scoping Review.

BACKGROUND: Surface coating technology can assist fixed appliances by reducing friction, improving antibacterial characteristics, and increasing corrosion resistance. The application of functional coatings composed of graphene onto the surfaces of orthodontic brackets and archwires has been shown to enhance their mechanical qualities. The objective of the current study was to carry out a scoping analysis of published recent evidence on the utilization of graphene as a covering material in metallic orthodontic accessories, such as brackets and archwires; Methods: A scoping review was undertaken following the PRISMA-ScR guidelines. PubMed, Embase, the Cochrane Library, Dentistry and Oral Science Source, and Google Scholar were searched between 2003 and 2023; Results: In total, 38 potential references were detected, from which 10 were selected for this review. These articles addressed the benefits of the application of graphene-oxide functional coatings onto the surface of archwires and brackets during fixed orthodontic treatment. Orthodontic graphene-oxide-based coatings provide improved surface characteristics (e.g., reduced friction and anticorrosive effects), antibacterial capabilities, and biocompatibility. These characteristics can increase the effectiveness of orthodontic therapy, improve patient comfort, and lower the likelihood of problems; Conclusion: Orthodontists should be aware of and comprehend the prerequisites for using graphene-oxide-coated archwires and brackets to fulfill needs throughout their clinical practice.

Synthesis of a PVA drug delivery system for controlled release of a Tramadol-Dexketoprofen combination.

The local administration of analgesic combinations by means of degradable polymeric drug delivery systems is an alternative for the management of postoperative pain. We formulated a Tramadol-Dexketoprofen combination (TDC) loaded in poly(vinyl alcohol) (PVA) film. Films were prepared by the solvent casting method using three different molecular weights of PVA and crosslinking those films with citric acid, with the objective of controlling the drug release rate, which was evaluated by UV-vis spectrometry. Non-crosslinked PVA films were also evaluated in the experiments. Differential scanning calorimetry (DSC) analysis of samples corroborated the crosslinking of PVA by the citric acid. Blank and loaded PVA films were tested in vitro for its impact on blood coagulation prothrombin time (PT) and partial thromboplastin time (PTT). The swelling capacity was also evaluated. Crosslinked PVA films of higher-molecular weight showed a prolonged release rate compared with that of the lower-molecular-weight films tested. Non-crosslinked PVA films released 11-14% of TDC. Crosslinked PVA films released 80% of the TDC loaded (p < 0.05). This suggests that crosslinking films can modify the drug release rate. The blank and loaded PVA films induced PT and PTT in the normal range. The results showed that the polymeric films evaluated here have the appropriate properties to allow films to be placed directly on surgical wounds and have the capacity for controlled drug release to promote local analgesia for the control of postoperative pain.

Calcium hydroxide/iodoform nanoparticles as an intracanal filling medication: synthesis, characterization, and in vitro study using a bovine primary tooth model.

The aims of this in vitro study were to synthesize, characterize, and evaluate the efficacy of a Calcium Hydroxide/Iodoform nanoparticles (CHIN) paste compared with Ultrapex as intracanal filling medication using an experimental model of bovine primary teeth. CH nanoparticle synthesis was performed via the simple hydrolysis technique of reacting calcium nitrate with sodium hydroxide. SEM-EDS and FT-IR analyses were used to characterize the obtained product. 30% of CH nanoparticles were combined with 40% of iodoform and 30% silicone oil to prepare an intracanal filling paste (CHIN). All endodontic procedures were performed on 34 uniradicular primary bovine teeth. Every root canal was instrumented with K files (up to #35) and obturated with the nanoparticle paste (experimental) or Ultrapex® (control). Three outcome variables were studied: penetration depth through the root dentinal tubules, Ca2+ ion release, and filling paste dissolution rate. The obtained data were analyzed by Student's t test. The X-ray diffraction pattern of CH nanoparticles showed characteristic peaks at CH, as confirmed by FT-IR analyses in which an intense signal was observed at 3643 cm-1, characteristic of CH. In the morphological characterization, CH particles could be detected at the nanosize scale. When applied as intracanal filling, the CHIN paste exhibited a higher level of penetration through the root dentin tubules. The global mean penetration measures were 500 µm for the experimental paste and 380 µm for the control paste (p < 0.05). The release of Ca2+ ions (up to the seventh day) and the dissolution rate were significantly higher in the experimental paste group than in the control group. No significant differences were observed between the groups regarding pH levels. The findings of this study suggest the potential suitability of CHI nanoparticles as an alternative intracanal filling medication for infected or devitalized primary teeth.

Calcium sustained release, pH changes and cell viability induced by chitosan-based pastes for apexification.

We explored chitosan-based sustained release pastes for apexification. The study aimed to formulate chitosan-based pastes loaded with calcium hydroxide (CH) or with calcium chloride (CC), and to evaluate the sustained release of Ca2+ and pH changes in deionized water as well as the effect of the pastes on cell viability. The pastes were formulated by dissolution of the chitosan in 1% or 2% acetic acid (AAC) plus the addition of CH or CC, then were suspended in deionized water for 50 days; the released Ca(II) and pH were measured with an electrode probe. The effect of the pastes on viability of human dental pulp cells was evaluated with a MTS assay. The results showed that the pastes prepared with 1% and 2% AAC and loaded with CH released a 74.9% and a 76.1% of the Ca2+ content, respectively, while the pastes prepared with 1% and 2% AAC loaded with CC released a content of Ca2+ of 90.8% and 76.6%, respectively. A control paste (CH and polyethylene glycol) released a 95.4%; significant statistical differences were found between the percentage of the experimental pastes and the control. The CH-loaded pastes caused an alkaline pH at the starting of the study, but the pH became neutral at the ending. The pH of the CC-loaded pastes was neutral at the starting and was acid at the ending. The pastes no affected on the cell viability. The chitosan-based pastes showed a suitable sustained release profile and cytocompatibility.