Detection and Identification of Various Microplastics in Different Orthodontic Adhesives.

Background Microplastics are acknowledged as significant environmental contaminants. The clinical use of dental materials, particularly adhesives containing plastic polymers, can give rise to the production of plastic micro- and nanoparticles, which subsequently find their way into the environment. The aim of the study was to detect different microplastics and identify them in various orthodontic adhesives. Materials and methods Four different light cure orthodontic adhesives, including Transbond XT (3M Unitek, Monrovia, CA), Ormco Enlight (Ormco, Orange, CA), Orthofix SPA (Orthofix, Verona, Italy), and Aqualine LC (Tomy International Inc, Tokyo, Japan), were collected and placed in separate Eppendorf tubes. Microplastics present in each adhesive were identified using scanning electron microscopy. Subsequently, each specimen was suspended in hydrogen peroxide, placed within a shaking incubator, and analyzed using Fourier transform infrared spectroscopy (FTIR) to identify the type of polymer. Results The scanning electron microscope shows the surface morphology and the most predominant types of microplastics identified were fibers, fragments, and pellets. FTIR results showed the presence of several major functional groups, including hydroxyl, amine, ester, fluoro, and halo groups. Conclusion When contrasted with the quantity of microplastic waste generated by other sectors like the textile, cosmetic, and fishing industries, the microparticulate waste stemming from dental adhesives has a minimal effect on environmental deterioration. Strategies for addressing this concern should give precedence to reducing the use of these materials and adopting effective recovery methods, which could potentially involve recycling processes.

Comparison of the effectiveness of piezocision-aided canine retraction augmented with micro-osteoperforation: a randomized controlled trial.

OBJECTIVE: To evaluate the effectiveness of micro-osteoperforation (MOP) on the rate of piezocision-aided canine retraction (CR). MATERIALS AND METHODS: The split-mouth study included 25 participants at the stage of commencing CR. The participants received flapless piezocision bilaterally at T0 (0 months) and MOP only on one side at T3 (3 months). The quadrant that received MOP at T3 served as the intervention, whereas the other quadrant served as the control. The primary outcome was the rate of CR, assessed using digital models. The angular change (AC) of the canine and the change in the buccal cortical bone thickness (BCBT) from before to after CR were also assessed using cone beam computed tomography. RESULTS: The rate of CR was 0.82 ± 0.39 mm/month in the control quadrant vs 0.75 ± 0.44 mm/month in the intervention quadrant (P > .05). The AC of the canine was 2.00° ± 0.88° in the control quadrant vs 1.98° ± 0.86° in the intervention quadrant (P > .05). The crestal bone gain was 0.50 mm in the control quadrant vs 0.28 mm of bone loss in the intervention quadrant. The bone thickness at a 3-mm height was increased by 0.11 mm in the control quadrant vs a 0.29-mm decrease in the intervention quadrant. The bone thickness at a 6-mm height was decreased by 0.12 mm in the control quadrant vs a 0.15-mm decrease in the intervention quadrant. However, none of the changes or group differences in bone height or thickness were statistically significant (P > .05). CONCLUSIONS: The periodic activation of a piezocision-aided CR site using MOP had no significant positive effect on the rate of CR, angulation of the canine, or changes in BCBT.

Green Synthesis and Characterization of Xanthium strumarium-Mediated Titanium Dioxide Nanoparticles.

Background Green synthesis of nanoparticles is a growing trend. The annual plant Xanthium strumarium L. (X. strumarium) belongs to the Asteraceae family. The herb has traditionally been used to treat a variety of ailments, including leucoderma, dangerous insect bites, epilepsy, salivation, allergic rhinitis, sinusitis, etc. Inorganic, biocompatible, and non-toxic titanium is a substance employed in the pharmaceutical and biomedical industries as well as in fields like bone tissue engineering. The aim of the study is to characterize titanium dioxide nanoparticles (TiO2NPs), which were synthesized from X.strumarium. Also, this study aims to assess the cytotoxic properties of the synthesized leaf extract and the TiO2NPs. Materials and methods In this study, the biosynthesis of TiO2NPs was made from X. strumarium leaf extract. The characterization of the green-synthesized TiO2NPs was done using the spectral analysis of an ultraviolet (UV)-visible spectrophotometer, scanning electron microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). The advantage of using TiO2NPs is that they possess antimicrobial, antibacterial, chemical stability, and catalytic properties. The leaf extract and the biosynthesized nanoparticles were tested against human fibroblast cell lines for biocompatibility using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay.  Results SEM investigation showed that TiO2NPs were crystalline in nature. FTIR confirms the presence of alkyne and amine functional groups, and the pointed vertices in the X-ray diffraction (XRD) pattern show the crystalline nature of TiO2NPs. The study found that the cell viability of TiO2NPs was 110%. Conclusion TiO2NPs were synthesized from X. strumarium leaf extract and characterized using SEM, FTIR, and XRD. The TiO2NPs were found to be crystalline in nature with various functional groups. MTT assay shows that the synthesized nanoparticles are promising biocompatible agents that can be used in future research in the medical field.

Mandibular Posterior Anatomic Limit for Distalization in Patients With Various Patterns of Third Molar Impactions: A Three-Dimensional Cone Beam CT (CBCT) Study.

AIM: The aim was to compare and evaluate the variation in the mandible's posterior anatomic limits (MPAL) stratified by different third molar impaction patterns utilizing cone-beam CT (CBCT) in individuals with skeletal Class III malocclusion. METHODOLOGY: The sample consisted of CBCT records of 80 samples of Class III patients categorized based on the pattern of their third molar impaction. The shortest linear distances from the distal root of the second mandibular molar to the inner cortex of the mandibular body were measured at the crown level, at the cementoenamel junction (CEJ), and at the depths of 4, 6, and 8mm from the CEJ, all parallel to the posterior occlusal line. The MPAL of the four groups were compared. The Shapiro-Wilk test for normality was performed. The Kruskal-Wallis test was performed to compare the MPAL distances between the groups. RESULTS: Significant differences were noted between the four groups at every level. MPAL distances decreased towards apex in all the groups and was least at the 8mm root level. The greatest MPAL distances were noted in the no-impaction group followed by the horizontal. At 8mm, the MPAL were 4.2+/-1.3 in Group 3 (Control), 3.3+/-0.9 in Group 1 and 2.7+/-0.05 mm in Group 2. Though the amount of space available for distalization was greatest for the mesioangular group at the crown level, it was least at the 8mm level compared to other groups. CONCLUSION: MPAL distances were shortest at the root level in Class III patients who had mesioangularly impacted third molars and care should be taken before attempting distalization in them.

Vacuum-Formed Retainers Versus Lingual-Bonded Retainers: A Systematic Review and Meta-Analysis of Stability of Treatment Outcomes in Orthodontically Treated Patients.

OBJECTIVE: This review aimed at analyzing the literature comparing vacuum-formed retainers and lingual-bonded retainers for maintaining treatment stability and periodontal health and evaluating retainer failure and patient satisfaction. METHODS: Electronic databases such as PubMed, Cochrane Library, Ovid, Scopus, Web of Science, and Google Scholar were searched. Only randomized controlled trials were involved. Risk of bias was evaluated using Risk of Bias 2 Tool. Meta-analysis was performed and certainty of evidence was assessed with Grading of Recommendations Assessment, Development, and Evaluation approach. RESULTS: Five randomized controlled trials were included for qualitative analysis and 2 studies were included for quantitative analysis. Two studies concluded that lingual-bonded retainers were more effective than vacuum-formed retainers in maintaining treatment stability. Two studies had a high risk of bias and 3 studies had some concerns. No statistically significant difference in Little's Irregularity Index (standard mean difference = -0.10; P value = .61), inter-canine width (standard mean difference = 0.66; P value = .09), inter-molar width (standard mean difference = 0.08; P value = .85), arch length (standard mean difference = -0.18; P value = .60) between the 2 retainers was noted. Periodontal status and retainer failure rate (odds ratio= 2.28; P value = .23) were similar in both retainers. Patient discomfort, soreness, and speech difficulty were more with vacuum-formed retainers and oral hygiene maintenance was easier with vacuum-formed retainers. CONCLUSION: A very low-level certainty of evidence suggests that both vacuum-formed retainers and lingual-bonded retainers were equally effective in maintaining treatment stability. Periodontal status and retainer failures were similar in both retainers. Vacuum-formed retainers were better for oral hygiene maintenance but were associated with discomfort, soreness, and speech difficulty than lingual-bonded retainers.

Comparative Evaluation of Two Bis-GMA Based Orthodontic Bonding Adhesives - A Randomized Clinical Trial.

INTRODUCTION: Of the various orthodontic bonding materials, orthofix is a fairly new entrant into this field. This material was exclusively introduced for orthodontic bonding purposes; however, the application of this material for orthodontic purpose has not been scientifically evaluated so far. AIM: The aim of the present study was to evaluate by an in-vivo double blinded split mouth rando mized clinical trial, the overall bond failure rates of two Bis-GMA based composite materials namely Transbond XT and Orthofix. MATERIALS AND METHODS: Thirty three participants who fulfilled the inclusion criteria were randomly allocated by lottery method into two groups. Group A participants had maxillary right and the mandibular left quadrants bonded using Orthofix and the remaining quadrants were bonded using Transbond XT. In Group B, the quadrants were reversed. Both groups were followed for a period of six months and were reviewed every 3-4 weeks. If a bond failed, the details were recorded and the duration of treatment before each breakage was calculated. Data were analyzed using Independent t-test and chi-square test. (p< 0.05) at 90% power. RESULTS: The overall bond failure rate for 263 brackets was 2.7% for Orthofix and 3.6% for Transbond XT. The mean esitmated survival time was 221.58 days for Transbond XT and for Orthofix was 220.07 days. The difference between these mean values were statistically insignificant (p>0.05). Similarly, failure rates of the anterior and posterior segment were compared and no difference was observed between the groups (p>0.05). The maxillary and mandibular teeth were compared and more failures were found in the mandibular teeth among both the groups but they were not statistically significant (p>0.05). CONCLUSION: The overall bond failure rate and mean survival time for Transbond XT was similar to Orthofix with no statistically significant difference.

Stress distribution patterns at mini-implant site during retraction and intrusion--a three-dimensional finite element study.

BACKGROUND: The purpose of this study was to evaluate the stress patterns produced in mini-implant and alveolar bone, for various implant dimensions, under different directions of simulated orthodontic force, using a three-dimensional finite element method. METHODS: Eight finite element (FE) models of mini-implant and bone were generated with insertion angles of 30° and 60°, diameters of 1 and 1.3 mm, and lengths of 6 and 8 mm. A simulated constant orthodontic force of 2 N was applied to each of these FE models in three directions simulating anterior retraction, anterior intrusion and retraction, and molar intrusion. RESULTS: Comparison of the maximum von Mises stress in the mini-implant showed that the 1-mm diameter produced significantly high stress, and the amount of stress produced was more for a mini-implant inserted at an angle of 60°. The cortical bone showed that high stresses were generated for the 1-mm-diameter mini-implant and on increasing the insertion angulation from 30° to 60°, the stress produced increased as well. The comparison of von Mises stress in the cancellous bone was insignificant as the amount of stress transmitted was very low. CONCLUSIONS: The 1-mm-diameter mini-implants are not safe to be used clinically for orthodontic anchorage. The 1.3 × 6 mm dimension mini-implants are recommended for use during anterior segment retraction and during simultaneous intrusion and retraction, and the 1.3 × 8 mm dimension mini-implant is recommended for use during molar intrusion. All mini-implants should be inserted at a 30° angle into the bone for reduced stress and improved stability.