Near-infrared laser-activated PLGA-PDA core-shell nanohybrids for synergistic photothermal antibacterial therapy and sustained ion release in orthodontic white spot lesions prevention.

Background It is essential to use orthodontic composites that possess favorable properties specifically; those that can be easily removed at the end of treatment but remain securely bonded during the course of treatment. Nanoparticles have gained attention for their antibacterial effects when incorporated into composite resins. However, the impact of nanoparticle incorporation in the adhesive and its relation with bracket failure rate has not been widely explored. Aim The aim of this study was to evaluate and compare clinical bracket failure rate of orthodontic adhesive modified with silver nanoparticles (AgNPs) with conventional orthodontic adhesive without AgNPs. Materials and Methods This in vivo study included patients aged between 15 and 35 years with mild-to-moderate crowding and healthy periodontium, requiring fixed orthodontic treatment with 0.022” × 0.028” slot metal brackets. Synthesis of colloidal AgNPs was performed using sodium tetrahydridoborate (NaBH 4 ) as the reducing agent. 0.09% w/w of AgNP were manually mixed in one syringe of orthodontic adhesive (3M Unitek Transbond XT) using mortar and pestle. Twenty patients (10 each group) were selected who met the inclusion criteria and allocated to the control and experimental groups using the lottery method. A total of 195 teeth (96 control, 99 experimental) were bonded. Brackets in the experimental group used adhesive (3M Transbond XT) modified with AgNP, while the control group used conventional adhesive (3M Transbond XT). Bracket failure rate was recorded over 4.5 months. The wire sequence used was 0.012 Niti, 0.016 Niti, 0.018 SS, 17x25 Niti, 19x25 Niti, and lastly 19x25 SS. Descriptive statistics, Kaplan–Meier plots, and log-rank tests were used to compare failure rates. Result Bracket failure rates were assessed using the Kapla–Meier plots which showed the survival (failure) rate of control and experiment group being 81.3% and 82%, respectively. There is no statistically significant difference in survival estimates of control and experimental group. Both survival curves start at 100% and show minimal decline across the 140-day period. The debonding occurred more on the initial aligning wires, that is, 0.016 Niti (control group) and 0.012 Niti (experimental group) between 24 and 75 days in average. Rate of bracket failure was higher in posterior teeth (15%) as compared to anterior teeth (3%). Conclusion The study found that orthodontic adhesive containing AgNP exhibited a 0.7% lower bracket failure rate compared to conventional adhesive. Bracket failures were more frequent in posterior teeth than anterior teeth. Further long-term studies with larger sample sizes are recommended to validate the effectiveness of AgNPs in orthodontic adhesives.

BACKGROUND:An ideal orthodontic adhesive should provide a bond strong enough to withstand the forces of orthodontic treatment and mastication without dislodging, while also being safe enough to prevent surface damage debonding. Shear bond strength (SBS) is a critical factor that determines the quality of bonding in orthodontics. Nanoparticle-enhanced adhesives have been reported to offer additional benefits such as antimicrobial properties and remineralization effects, making them worth investigating for their shear bond characteristics. Aim: This in vitro study aimed to evaluate and compare the SBS and Adhesive Remnant Index (ARI) scores of orthodontic adhesives containing copper-substituted hydroxyapatite (Cu-HA) nanoparticles with a conventional orthodontic adhesive.MATERIALS AND METHODS:Twenty-eight extracted human premolar teeth were randomly divided into two groups of 14. In Group 1, orthodontic brackets were bonded using Enlight adhesive mixed with Cu-HA nanoparticles, while Group 2 used conventional Enlight adhesive. SBS was measured using a Universal Testing Machine, and the debonded samples were evaluated for ARI scores under scanning electron microscopy (SEM). Statistical analyses were performed using independent t-tests for SBS comparison and Mann-Whitney U tests for ARI score differences. A P value < 0.05 was considered statistically significant.RESULTS:The group using Enlight adhesive with Cu nanoparticles exhibited a significantly higher mean SBS (9.03 ± 6.17 MPa) compared to the conventional adhesive group (5.51 ± 2.099 MPa, P = 0.003). The median ARI score for the Cu-HA nanoparticle group was 3, while the conventional group had a median ARI score of 2 (P = 0.022). Both SBS and ARI scores were significantly higher in the Cu-HA nanoparticle group.CONCLUSION:Copper-substituted hydroxyapatite nanoparticles enhance bond strength and adhesive retention, making them a promising alternative to conventional adhesives in orthodontics.CLINICAL RELEVANCE:The findings indicate that adhesives containing Cu-HA nanoparticles, especially when combined with the Enlight adhesive, offer superior bond strength and adhesive retention compared to conventional adhesives. This could lead to improved clinical outcomes in orthodontic bonding, potentially reducing bracket failure rates and enhancing treatment efficiency.

ABSTRACTObjective:This study aimed to compare the bond strength of orthodontic adhesives that are conventional and light-cured among 800 patients on orthodontic treatment. The research attempts to give insightful clinical information regarding the type of adhesive that produces greater bond strength and endurance.Materials and Methods:A total of 800 patients, between the ages of 12 and 40 years, needing fixed orthodontic treatment, were selected for the study. The participants were divided into two groups, each consisting of 400 participants. The participants in Group A were bonded using a chemically cured composite adhesive and those in Group B were bonded with a light-cured resin-based composite adhesive. Bonding protocols were made uniform, and shear bond strength was tested with a universal testing machine. Failure force was measured at its peak in megapascals (MPa).Results:The chemically cured adhesive group presented a mean shear bond strength of 10.5 MPa (±2.4), whereas the light-cured adhesive group presented a higher mean bond strength of 13.8 MPa (±2.0). Statistical analysis (independent t-test) indicated that there was a significant difference (P = 0.003, P < 0.01) in bond strength between the two adhesives, wherein the light-cured resin composite adhesives were superior. Age, gender, and enamel condition were also controlled in analysis, and enamel condition was found to significantly influence bond strength (P = 0.02). The teeth with improved enamel quality had improved scores of bond strength. The odds ratio for improved bond strength with light-cured adhesive was 2.41, showing an improved bonding effect.Conclusion:Light-cured adhesive was more bond-strength than conventional adhesives. The results indicate that light-cured adhesives could provide more durability and reliability for orthodontic treatment, and have potential implications for adhesive choice in clinical practice.

An umbrella review of systematic reviews/meta-analyses evaluating the antimicrobial activity of various nanoparticles on orthodontic materials & components.

Background: Orthodontic treatment with fixed appliances is frequently associated with difficulties in maintaining good oral hygiene and creation of plaque-retentive areas on tooth surfaces that are typically more prone to the development of caries; such drawbacks may result in white spot lesion (WSL) development that affects the esthetic outcome following bracket debonding. This review article focuses on orthodontic WSLs development, prevention, and remineralization potential via incorporating various remineralizing / antibacterial additives into orthodontic adhesives. Results: Unbalanced enamel demineralization and remineralization processes, along with rapid alterations in the dental plaque bacterial ecology, particularly acidogenic bacteria, are the causes of the start and progression of a carious lesion. Without significantly compromising an adhesive mechanical performance, several antibacterial and remineralizing substances have been added to orthodontic adhesives in an effort to reduce bacterial colonization and promote remineralization. Conclusions: Antibacterial and/or remineralizing substances were utilized as additives in the creation of innovative orthodontic adhesive systems to address white spot lesions (WSLs) and improve the ability of enamel remineralization. Compared to adding only one agent, including multiple agents in an orthodontic adhesive system may have a greater impact on lowering enamel demineralization and improving enamel remineralization during orthodontic therapy.

Silver nanoparticles (AgNPs) have gained significant attention in dentistry due to their potent antimicrobial properties. This scoping review aimed to assess the antimicrobial activity of AgNPs and their applications across different dental specialties. The study followed the Joanna Briggs Institute (JBI) methodology. A total of 43 studies met the inclusion criteria and were categorized based on their focus areas. The findings indicate that AgNPs exhibit strong antimicrobial activity against oral pathogens such as Streptococcus mutans and Enterococcus faecalis, with applications ranging from orthodontic adhesives and root canal disinfectants to coatings for dental implants and prostheses. The review highlights that AgNPs can prevent microbial colonization, reduce biofilm formation, and serve as an alternative to traditional antimicrobial agents, potentially mitigating antibiotic resistance. However, concerns regarding their cytotoxicity and long-term biocompatibility persist. Further in vivo research is needed to validate their efficacy and safety in clinical settings. Future studies should focus on optimizing AgNP concentrations and assessing potential side effects. This review provides an overview of the current evidence on AgNPs in dentistry and emphasizes the importance of further research for their safe and effective clinical application.

Degree of monomer conversion upon light-curing condition, biaxial flexural strength, and surface apatite formation of orthodontic adhesive containing calcium phosphate and nisin

This study was to assess the effects of nanoAg-ACP microparticles as additional fillers on the shear bond strength of Phase II Dual Cure orthodontic adhesive and the enamel demineralisation of teeth using such adhesive. Experimental adhesive was formulated by incorporating 2.5 wt% nanoAg-ACP microparticles into Phase II Dual Cure immediately before use. Brackets were bonded to extracted human premolars using Phase II Dual Cure for one group and experimental adhesive for the second. Samples in each group were randomly assigned to three sub-groups for different post-bonding treatments. Debonding force was measured after post-bonding treatments and used to calculate shear bond strength. DIAGNOdent was used to assess enamel demineralisation for sub-groups treated with acid gels. The shear bond strength for Phase II Dual Cure and experimental adhesive was 19.06 ± 2.88 and 13.90 ± 2.22 MPa, respectively, after 24-h aging, 15.98 ± 5.44 and 15.31 ± 4.22 MPa, respectively, after 5-month aging, and 14.72 ± 3.15 and 14.46 ± 4.66 MPa, respectively, after 3-week demineralisation following 5-month aging. After being aged for 5 months and demineralisedfor 3 weeks, samples bonded using Phase II Dual Cure had a higher DIAGNOdent value of 65.00 ± 14.66 compared to 49.77 ± 20.64 for samples bonded using experimental adhesive (p < 0.05). NanoAg-ACP microparticles could be added into Phase II Dual Cure as fillers to resist demineralisation without impairing the shear bond strength. The results warrant further investigation of nanoAg-ACP microparticles as fillers for orthodontic adhesives using more clinically relevant invitro models to confirm their potential clinical application in orthodontic treatments.

ObjectiveThis study evaluated enamel demineralization, shear bond strength, and failure modes associated with orthodontic adhesives containing silver nanoparticles (AgNPs).MethodsForty-eight extracted human premolar teeth were selected and evenly divided into two groups based on the intended assessments, with 28 specimens in each group: Part I focused on enamel demineralization depth, and Part II addressed shear bond strength and failure modes. Specimens were prepared, mounted, and bonded using two adhesive systems: Group A used a conventional adhesive system without AgNPs, while Group B employed a conventional adhesive system mixed with AgNPs. In Part I, specimens underwent artificial demineralization at pH 4.5°C and 37°C for 7 days, followed by buccolingual sectioning. The depth of demineralization was measured using a scanning electron microscope and analyzed with ImageJ software. In Part II, shear bond strength was assessed using a universal testing machine, followed by failure mode evaluation using a stereomicroscope.ResultsResults showed that Group A exhibited a significantly greater demineralization depth compared to Group B (p = 0.000). However, no significant difference was observed between overall location levels (p = 0.093). Additionally, Group B demonstrated significantly higher shear bond strength (p = 0.000) and a more uniform distribution of failure modes compared to Group A.ConclusionsThese findings suggest that incorporating silver nanoparticles into orthodontic adhesives reduces demineralization depth and enhances shear bond strength compared to conventional adhesive systems. In contrast, conventional adhesives were associated with a higher incidence of adhesive mode failure.

ABSTRACTBackground:Orthodontic adhesives are prone to bacterial colonization, leading to demineralization and white spot lesions during orthodontic treatment. Incorporating antimicrobial agents such as metal-organic frameworks (MOFs) into adhesives offers a novel approach to mitigate bacterial growth.Materials and Methods:A commercially available orthodontic adhesive was modified by incorporating 5% and 10% weight concentrations of a zirconium-based MOF. Samples were prepared and tested for antimicrobial efficacy against Streptococcus mutans using a zone of inhibition assay and a bacterial colony counting technique. Shear bond strength (SBS) was tested following the ISO/TS 11405 standards. The release of antimicrobial ions from the adhesive was measured over 14 days. Data were analyzed using ANOVA and post hoc tests, with statistical significance set at P < 0.05.Results:The modified adhesives showed significant antimicrobial activity, with a reduction in bacterial colony counts of 72% and 85% for 5% and 10% MOF concentrations, respectively. The zone of inhibition increased proportionally with MOF concentration. The 5% MOF adhesive exhibited a slight reduction in SBS (mean: 18.2 ± 1.5 MPa) compared to the control (mean: 20.1 ± 1.2 MPa), whereas the 10% MOF adhesive showed a more pronounced decrease (mean: 15.6 ± 1.8 MPa). Ion release profiles indicated sustained antimicrobial activity over the test period.Conclusion:The incorporation of MOFs into orthodontic adhesives effectively enhances antimicrobial properties while maintaining acceptable mechanical performance at lower concentrations. This innovative approach could help reduce the risk of enamel demineralization during orthodontic treatment.

Background:Cetylpyridinium chloride (CPC) is a quaternary ammonium compound extensively used in oral hygiene products for its potent antimicrobial and antiviral activity. Its mechanism involves disruption of microbial cell membranes through electrostatic and hydrophobic interactions. In addition to its oral applications, CPC has gained attention for integration into biomaterials and potential to mitigate SARS-CoV-2 transmission, warranting a comprehensive review of its biomedical relevance. Materials and Methods:A systematic review was conducted following PRISMA guidelines across PubMed, ScienceDirect, and Google Scholar (1990–2023), using terms related to CPC's antimicrobial, antiviral, and material- incorporation functions. Eligible studies included in vitro, in vivo, and clinical investigations assessing CPC’s efficacy, mechanisms, and integration into dental materials. Articles were screened, data extracted, and quality assessed using CONSORT and STROBE tools. Due to heterogeneity, findings were synthesized qualitatively. Results:Evidence supports CPC's significant antimicrobial efficacy in reducing plaque, gingivitis, and biofilm formation, with up to 30% improvement over controls. It exhibits broad-spectrum bactericidal action, though polymicrobial biofilms show reduced susceptibility. CPC also demonstrates &gt;99.9% inactivation of SARS-CoV-2 in vitro, indicating prophylactic potential. Its incorporation into orthodontic adhesives and resins yields sustained antimicrobial effects, though material strength may decline over time. Emerging resistance and biofilm penetration barriers highlight key limitations. Conclusion:CPC is a versatile antimicrobial with proven utility in oral care and public health. Its efficacy against bacterial and viral pathogens, including SARS-CoV-2, and potential for biomaterial integration underscore its translational value. However, long-term biocompatibility and resistance development require further research to optimize its application across clinical domains.

This study examined the degree of monomer conversion (DC) and mechanical properties of experimental orthodontic adhesives containing monocalcium phosphate monohydrate (MCPM), Sr-bioactive glass (Sr-BAG) nanoparticles, and andrographolide. Experimental adhesives were prepared with a 4:1 powder-to-liquid ratio, containing methacrylate monomers with varying formulations of glass fillers and additives. DC was measured using ATR-FTIR (n = 5) with and without bracket placement under two curing protocols: conventional LED (1200 mW/cm2, 20 s) and high-intensity LED (3200 mW/cm2, 3 s). The biaxial flexural strength and modulus were tested after 4-week water immersion (n = 8). Transbond XT was used as the commercial comparison. Transbond XT exhibited higher DC (33-38%) than the experimental materials. Conventional LED curing produced higher DC than high-intensity LED, while bracket placement reduced DC by approximately 10% in the experimental materials but minimally affected Transbond XT. Transbond XT demonstrated a superior biaxial flexural strength (188 MPa) compared to the experimental adhesives (106-166 MPa, p < 0.05). However, the experimental formulations with low additive concentrations showed a comparable biaxial flexural modulus (5.0-5.5 GPa) to Transbond XT (5.6 GPa) (p > 0.05). Although the experimental adhesives exhibited lower DC and strength than the commercial product, their values still met the ISO standards, suggesting their potential clinical viability despite their modified compositions.

Background and Objectives: The most common method for treating malocclusions today is fixed orthodontic therapy, during which brackets and tubes are bonded to the surface of the teeth, which makes oral hygiene difficult to maintain. Increased plaque retention, gingival bleeding, and gingivitis can be diagnosed in the early phases of treatment. The periodontal response to plaque accumulation can be explained by quantitative and qualitative changes in the subgingival microbiota. The aim of our research was to investigate the changes in the subgingival microbiota that occurred within 6-8 weeks after bonding when two different orthodontic adhesives were used. Materials and Methods: Thirty patients were followed; molar tubes were bonded with a composite (C) in fifteen cases, and in the other fifteen cases, they were bonded with glass ionomer cementum (GIC). A microbiological sample was taken from the gingival sulcus of the maxillary first molars at the time of appliance placement (T1) and 6-8 weeks (T2) after bonding. Bacterial DNA detection was performed using the micro-IDent®plus11 (Hain Lifescience GmbH, Germany) PCR (polymerase chain reaction) method. The statistical analysis included McNemar's test to analyze the paired binary data and Fisher's Exact Test to compare the prevalence of each of the 11 bacteria at T1 and, ultimately, T2 between the two studied groups. The Bonferroni correction was also applied. Results: When analyzing GIC vs. C at T1 and T2, none of the studied pathogens showed significant differences. Conclusions: Given the lack of statistical significance, these trends do not confirm a definitive impact of the procedure on bacterial presence. The increased presence of periodontal pathogens might suggest that bonding does not reduce the bacterial loading of subgingival microbiota. Less protective effects of the GIC intervention against Tannerella forsythia and Eubacterium nodatum bacteria were detected.

Comparative analysis of shear bond strength and debonding characteristics of bioactive versus conventional orthodontic adhesives: An in-vitro study

The Effect of Adding Luteolin Nanoparticles on the Antibacterial and Mechanical Properties of an Orthodontic Adhesive.

Assessment of Fluoridated Orthodontic Adhesive: Exploring Fluoride Release, Rechargeability, and Their Influence on Shear Bond Strength in Intact Tooth Surfaces

Introduction The success of orthodontic treatment depends on the adhesive performance of the bonding agents used to bond brackets to enamel. Conventional adhesives, such as Transbond XT (3M Unitek Corp., Monrovia, CA), have been widely utilized owing to their strong mechanical properties and clinical reliability. However, nanocomposites, such as amorphous calcium phosphate (ACP)-modified adhesives, have emerged as promising alternatives, offering potential benefits such as enhanced bond strength, remineralization properties, and better color stability. The present study aimed to compare nanocomposite and conventional adhesives in terms of bracket debonding rates and enamel discoloration over a six-month period. Materials and methods This prospective observational study was conducted in an orthodontic department between February and November 2024. Forty patients were included and divided into two groups: group 1 (n = 20 patients), where brackets (N = 400) were bonded using Transbond XT, and group 2 (n = 20 patients), where brackets (N = 400) were bonded using ACP-modified nanocomposite (Aegis Ortho, Bosworth Co. Ltd., Skokie, IL). All patients underwent the same orthodontic bonding protocol and were followed for six months. The bracket debonding time was recorded, and the change in enamel color (ΔE*) was assessed using a spectrophotometer (Vita Easyshade, Vita Zahnfabrik, Bad Säckingen, Germany). The Adhesive Remnant Index (ARI) was evaluated using a stereomicroscope at 20× magnification, and Kaplan-Meier survival analysis was used to assess bracket longevity. Statistical comparisons were conducted at p < 0.05. Results The mean debond time was 60.88 ± 20.68 days for Transbond XT and 66.58 ± 34.17 days for the nanocomposite group, with no significant difference (p = 0.876). The nanocomposite group showed lower color change (3.70 ± 0.50) compared to Transbond XT (3.95 ± 0.31), indicating better enamel color stability (p = 0.029). The nanocomposite group had more favorable failure modes, with a higher percentage of adhesive retention on enamel, reducing the risk of microleakage and enamel damage. Kaplan-Meier analysis suggested a slightly longer bracket survival in the nanocomposite group. Conclusion Nanocomposite adhesives exhibited bracket retention comparable to that of Transbond XT while demonstrating superior color stability and better ARI scores, indicating improved enamel adhesion and reduced enamel damage upon debonding. Given these advantages, nanocomposites are promising alternatives for orthodontic bonding.

Background/Objective: Many novel solutions for a range of dental problems are emerging as a result of the quick development of nanotechnology and nanocomplex synthetic techniques. The effectiveness, quality, and negative consequences of these advancements are occasionally debatable, though. This systematic review sought to better summarize the existing additions of nanoparticles to dental adhesive systems in order to improve their performance and properties, evaluate their quality, and examine the results that have been published. Materials and methods: The present systematic review was carried out according to PRISMA guidelines. The search was carried out on PubMed central, Cochrane collaboration, Science direct and Scopus scientific engines. Selected MeSH keywords (nanoparticles, adhesive resin, enamel demineralization) were used for data extraction. A total of 13 full-text original articles were included in the final analysis, and these articles were based on adding nanoparticles to the adhesive resin to evaluate their effects on enamel demineralization. Results: The literature search resulted in a total of 13 original studies/articles up until November 2024. The text articles comprised in vitro studies with robust inclusion and exclusion criteria. The review included various types of adhesives and nanoparticles, with amorphous calcium phosphate (ACP) being the most common. Other nanoparticles included polydopamine-Ag, bioactive glass, and silver. Most studies assessed the effects of nanoparticles on adhesive shear bond strength (SBS), microbial growth, and microhardness. Only three studies investigated the effects of nanoparticles on microhardness using Vickers tests. Conclusions: The review found that adding nanoparticles to orthodontic dental adhesives enhances their antibacterial and anticariogenic properties without affecting the shear bond strength. This could prevent enamel demineralization during orthodontic therapy. Future research could benefit from these positive properties, necessitating an interdisciplinary approach.

The effectiveness of adhesive materials used for bracket bonding is an important factor of orthodontic treatment that directly affects patient satisfaction and treatment success. It is important to know the advantages of various orthodontic adhesives to improve treatment results and reduce issues like enamel demineralization.To thoroughly evaluate and contrast the performance of different orthodontic adhesives in terms of enamel protection and bonding stability throughout orthodontic therapy. Following PRISMA criteria, a systematic search was carried out using several databases, including PubMed, Scopus, Web of Science, and the Cochrane Library. Medical Subject Headings (MeSH) terms and carefully chosen keywords were used in the search technique to find pertinent research published between 1989 and 2023 that included approximately 1465 total articles. The inclusion criteria covered studies that evaluated the efficacy of orthodontic adhesives for the reliability of bracket bonding and the preservation of enamel during orthodontic treatment. Six recognized papers that evaluated the efficacy of diverse orthodontic adhesives using disparate approaches. The results showed that different adhesive types varied in bonding strength, failure rates, cleanup times, and enamel protection. Significant distinctions were noted between adhesives that were chemically cured and those that were light-cured, as well as between adhesives based on resin and glass ionomer cement. While retaining a good bonding strength, compomer and composite resin adhesives shown potential benefits in lowering enamel decalcification. The significance of taking clinical results and bonding performance into account when choosing adhesive materials for orthodontic treatment is highlighted by a comparative examination of orthodontic adhesives. To improve treatment efficacy and patient care, future research efforts should concentrate on overcoming methodological constraints and further clarifying the mechanisms behind enamel protection and adhesive bonding strength.