The effects of rinsing and curing conditions on the biocompatibility of 3-dimensional-printed resin orthodontic brackets.

Orthodontic appliances increase the risk of enamel demineralization. Dental lasers have been reported to enhance enamel resistance to demineralization when applied prior to orthodontic procedures. This study aimed to evaluate the effects of Er, Cr: YSGG laser application, alone or in combination with fluoride, on enamel demineralization, surface hardness, and orthodontic shear bond strength. A total of 135 extracted human premolars were used. For Vickers hardness and ICP-OES analyses, 75 samples were divided into five groups: (1) negative control, (2) topical fluoride, (3) Er, Cr: YSGG laser, (4) laser combined with fluoride, and (5) positive control. Samples from Groups 2, 3, 4, and 5 were subjected to a demineralization procedure, and enamel hardness was subsequently measured. The demineralization solutions were analyzed using ICP-OES to determine calcium and phosphorus levels. For shear bond strength evaluation, four groups were prepared from the remaining 60 specimens. The same surface treatment protocols as those applied in Groups 1-4 of the microhardness test were used. Data were analyzed using SPSS software. The surface hardness of Groups 2, 3, and 4 was significantly higher than that of Group 5 (p < 0.05). The amounts of both calcium and phosphorus released in Group 5 were significantly higher than in the other groups. There were no statistically significant differences in calcium and phosphorus levels among Groups 2, 3, and 4. No significant differences in the shear bond strength of orthodontic brackets were observed among the groups. Within the limitations of this in vitro study, the application of Er, Cr: YSGG laser, either alone or in combination with fluoride, improved enamel resistance to demineralization compared to the demineralized control group, without adversely affecting the bond strength of orthodontic brackets. The combined application did not demonstrate a statistically significant additional benefit compared to single-modality treatments.

Segmental torque relevant orthodontic bracket tie-wing deformation in various bracket-archwire-ligature combinations.

BackgroundTo determine the impact of titanium dioxide nanotubes (nTiO2) incorporated into glass ionomer cement (GIC) on its shear bond strength (SBS) and failure pattern of orthodontic brackets bonded to enamel.MethodsSixty‐six molars were assigned to three groups (n = 22): Transbond XT (TXT) resin; GIC; and GIC + 5% nTiO2. SBS was performed using a universal testing machine, and failure patterns were assessed using the adhesive remnant index (ARI). Data were analyzed by generalized linear model and Fisher’s exact test (α = 0.05).ResultsTXT showed the highest SBS, followed by GIC and GIC + 5% nTiO2 (p < 0.05). ARI 0 was the most frequent in all groups, especially in GIC (p ≤ 0.05).ConclusionsIncorporating nTiO2 into GIC reduced the SBS and resulted in less material remaining on the enamel after debonding, suggesting a potentially reduced risk of enamel damage.Clinical RelevanceOrthodontic bracket bonding demands materials that combine reliable adhesion with enamel preservation. Incorporating nTiO2 into GIC slightly lowers bracket bond strength but reduces cement remnants on enamel, potentially minimizing enamel damage during debonding. This provides clinicians with a well‐supported alternative for orthodontic bonding that balances reliable adhesion with enhanced enamel preservation.

Background: Pain during orthodontic debonding is a common clinical concern. Although previous studies have mainly focused on mechanical approaches to reduce discomfort, the influence of emotional characteristics of patients on pain perception remains insufficiently explored. In this study, we aimed to evaluate the association between pain perception, emotional affect, and anxiety during orthodontic bracket removal using different clinical protocols. Methods: A prospective observational comparative study was conducted at Rey Juan Carlos University (Madrid, Spain). A total of 140 orthodontic patients underwent bracket removal according to four routine clinical protocols determined by clinical scheduling: ligated with interocclusal cotton rolls (used for tooth stabilization), non-ligated with cotton rolls, ligated without cotton rolls, and non-ligated without cotton rolls. Pain intensity was assessed using a Visual Analog Scale (VAS) immediately before (T0) and after (T1) bracket removal. Baseline pain (T0) was recorded to control for pre-existing discomfort. Anxiety and emotional affect were measured using the State-Trait Anxiety Inventory (STAI) and the Positive and Negative Affect Schedule (PANAS), respectively. Statistical analyses included ANOVA, factorial ANCOVA adjusted for baseline pain, and multivariable regression models. Results: No significant baseline differences were observed among groups. The highest post-debonding pain scores were found in the group without cotton rolls and without ligatures. ANCOVA revealed a significant main effect of cotton roll use, with lower adjusted pain scores in patients treated with cotton rolls, whereas ligation showed no statistically significant independent effect. In multivariable regression analyses, baseline pain, age, and negative affect were independently associated with higher post-debonding pain. Conclusions: Within the limitations of a non-randomized design, cotton roll use was associated with lower post-debonding pain, whereas ligation appeared to have a limited influence. Patient-related factors-particularly negative affect, age, and baseline pain-were also associated with pain perception, supporting a biopsychosocial perspective. These findings should be interpreted as exploratory evidence rather than causal effects.

Fixed orthodontic appliances facilitate bacterial accumulation on brackets and wires, increasing the risk of enamel demineralization and periodontal inflammation. To address this challenge, near-infrared (NIR) responsive nanofibrous mats were developed for on-demand antibacterial disinfection of orthodontic brackets by incorporating cuttlefish ink-derived melanin nanoparticles (MNPs) into a poly(vinyl alcohol)/poly(ethylene oxide) (PVA/PEO) matrix. The incorporation of MNPs improved physicochemical properties, including enhanced thermal stability (∼77 °C increase in decomposition temperature), increased swelling capacity (∼2-fold compared with melanin-free fibers), and improved wettability. After thermal cross-linking, the fibrous network remained structurally stable in aqueous conditions with morphology preserved for up to 1 month and low melanin loss. Strong antioxidant performance was observed, reaching ∼60% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging after 10 h. In vitro evaluation using L929 fibroblasts confirmed good cytocompatibility, supporting adhesion, viability, and proliferation. Under NIR irradiation at 808 nm (1.5 W/cm2, 10 min), efficient photothermal heating was achieved under wet conditions (∼55-60 °C) with stable performance across repeated cycles. Antibacterial efficacy was demonstrated, reducing Escherichia coli survival to 0.55% and disinfecting bacteria-contaminated bracket surfaces, while only minor inhibition of Lactobacillus acidophilus was detected. Overall, a biocompatible, marine-derived, and sustainable nanofibrous mat are presented for on-demand orthodontic disinfection.

Effect of different pH levels of in-office bleaching gels on teeth with orthodontic brackets bonded using two adhesive strategies: An in vitro comparative study.

BackgroundEnergy drinks are acidic beverages with recognized erosive potential, but their effect on enamel characteristics relevant to orthodontic bonding remains incompletely described. This in vitro study evaluated the effect of continuous 24-hour immersion in two commercial energy drinks, Red Bull and Code Red, on enamel surface morphology, elemental profile, surface roughness, and orthodontic bracket shear bond strength (SBS).MethodsThirty sound human lower premolars were randomly allocated to three groups (n = 10): distilled water (control), Red Bull, and Code Red. After 24 h of immersion at 37 °C, enamel was assessed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and SEM-derived surface roughness analysis. Stainless-steel premolar brackets were then bonded, and SBS was measured using a universal testing machine.ResultsUnder the accelerated laboratory exposure conditions used, both energy drinks produced evident enamel surface alterations compared with the control group. The control group showed the lowest roughness (Ra = 3.04), whereas Red Bull and Code Red increased roughness, with the highest values observed for Code Red (Ra = 24.9). Mean SBS decreased from 24.1 MPa in the control group to 17.7 MPa after Red Bull exposure and 12.7 MPa after Code Red exposure. EDX demonstrated lower calcium values after exposure to both drinks than in the control group.ConclusionsWithin the limitations of this acute in vitro immersion model, both tested energy drinks showed erosive potential and were associated with altered enamel surface characteristics and lower orthodontic bracket SBS compared with distilled water. These findings should be interpreted as laboratory evidence under accelerated exposure conditions rather than as direct evidence of the risk of clinical bracket failure.

This study evaluated and compared the accuracy of conventional alginate impressions and intraoral scans for orthodontic measurements and full-arch superimposition under clinical conditions with brackets and wires present. Intraoral scanners are increasingly used in orthodontics due to their advantages in efficiency, patient comfort, and digital workflow integration. However, concerns remain regarding their accuracy under clinical conditions, particularly in the presence of brackets and wires, which may introduce scanning artifacts. In vivo evidence evaluating their impact across sequential orthodontic stages remains limited. This in vivo study employed a within-subject comparative design, with conventional alginate models serving as the reference standard. Fifteen participants requiring orthodontic treatment were enrolled in this study. Five study models from each subject were obtained from (1) conventional alginate impression (Con), (2) intraoral scanning (Ios), (3) conventional alginate impression, (4) intraoral scanning after bonding with orthodontic brackets (ConBk and IosBk), and (5) intraoral scanning in subjects who were bonding with orthodontic brackets and wire insertion (IosBkW). The Con and ConBk models were poured and digitized using a laboratory scanner, while the intraoral scan data were exported as STL (Standard Tessellation Language) files. Linear measurements and superimposition analysis were performed in Ortho Analyzer software. Superimposition was performed using a landmark-guided registration protocol with standardized cross-sectional planes. Deviations were quantified as the maximum linear distance between corresponding cross-sectional profiles. Statistical comparisons were analyzed using Welch's analysis of variance and Games-Howell post hoc tests (p < 0.05). No statistically significant differences were observed in linear measurements between digital models obtained from intraoral scanners and conventional reference models across all orthodontic stages (p > 0.05). Intercanine and intermolar widths in both maxillary and mandibular arches showed high agreement with the conventional reference models, with minimal variations across conditions. For superimposition analysis, small but statistically significant deviations were detected in models with brackets and wires compared with the conventional reference (p < 0.001). However, these deviations were minor (-0.17 to -0.20 mm) and remained within clinically acceptable limits. Intraoral scanning can be confidently used throughout fixed-appliance therapy without removing brackets or wires when standardized scanning protocols are followed.

Tooth segmentation remains the most time-consuming task during model preparation for digital orthodontic setup. This study aimed to assess the accuracy of AI-based tooth segmentation tools of four widely used orthodontic platforms, namely Medit LINK (©Medit Corp, South Korea), DentOne (©DIORCO Co, South Korea), BlueSkyPlan (Blu Sky Bio, USA), and ArchForm, using models categorized by specific clinical characteristics. A total of 270 digital dental models were retrospectively selected and assigned to nine groups: aligned dentition, crowding, spacing, ectopia, agenesis, gingival recession, tooth wear, orthodontic brackets, and attachments. Automated labeling success and segmentation quality were evaluated for each software. Mesio-distal (MD) tooth widths were calculated using Meshmixer software (Autodesk, San Rafael, Calif) and compared with unsegmented models (ground truth). All data were statistically analyzed. BlueSkyPlan consistently outperformed the other tested software in tooth labeling, surface segmentation, and mesio-distal measurements accuracy across all model groups (P < 0.05). Labeling errors were most frequent in models with ectopic teeth (≤12.2% success) and agenesis (≤53.1% success). Surface-specific errors increased with crowding (buccal/lingual errors), spacing (mesio-distal errors), gingival recession (buccal errors), and tooth wear (occlusal errors). All software overestimated MD widths compared with ground truth with the limits of agreement considered clinically relevant (>0.30 mm) in specific software-model combinations). The software evaluated does not provide transparency regarding the AI technologies implemented. The accuracy of automatic segmentation of intra-oral scans is influenced by clinical and anatomical characteristics of the dental arches and still requires clinician supervision. BlueSkyPlan currently appears to provide the most reliable performance among the tested platforms.

Ex vivo evaluation of the antimicrobial properties, physical and mechanical characteristics, and cytotoxicity of orthodontic cement containing silibinin against Streptococcus mutans biofilm.

Shear bond strength of orthodontic metal brackets using Assure® Plus with and without Pro Seal®: An in vitro study.

The remineralization properties of two newly developed orthodontic primers.

The successful completion of orthodontic treatment largely depends on the accuracy of bracket placement. This study aimed to compare the impact of virtual simulation and traditional training on bonding, while also exploring student feedback regarding their learning journey. Twenty dental interns with no experience in orthodontics were randomly assigned either to a traditional training group (Group A) or a virtual simulation training group (Group B). Following their respective trainings, students placed orthodontic brackets on head-simulator models. Three-dimensional bracket deviations (mesiodistal, vertical, and buccolingual) from an ideal reference were quantified using the Geomagic Studio software. Participants' motivation and satisfaction were also assessed with the ARCS (Attention, Relevance, Confidence, Satisfaction) motivation and learning experience satisfaction questionnaires. Due to the non-normal distribution of the data, the Mann-Whitney U test was used to compare differences between two groups. The virtual simulation group had less deviation in bracket positioning in the mesiodistal and buccolingual directions than the traditional training group (P < .05). There was no statistically significant difference in the vertical directions (P > .05). Furthermore, the virtual simulation group scored higher in all questionnaire domains, although most of the differences were not statistically significant. Within the limitations of this pilot study, differences in selected aspects of the accuracy of bracket positioning were found to be associated with virtual simulation training. The findings suggest that virtual simulation provides learning outcomes comparable to those of traditional training without compromising technical accuracy from an educational perspective. Adoption of this technology is a great addition to modern dental educational curricula. However, more research with larger sample sizes is necessary. With the pilot nature of the study and limited statistical power, the results must be treated with caution.

Universal adhesives (UAs), introduced in 2011, are well established in restorative dentistry but remain relatively unexplored in orthodontics, where their capacity to bond to enamel and multiple restorative materials could simplify bonding protocols and reduce the need for primers. This systematic review evaluated the bond strength of UA for orthodontic applications-including bracket bonding, fixed retainers, and bonding to restorative surfaces-compared with conventional adhesives. Searches were conducted in PubMed, Embase, Scopus, Web of Science, and the Cochrane Library, supplemented by Google Scholar and reference lists. The protocol was registered in PROSPERO (ID: CRD420250654277). The search covered 2011 to 1 December 2024. Eligible studies were in vitro, in vivo, or clinical studies in English assessing UA for orthodontic bonding. Exclusion criteria were case reports, reviews, abstracts, theses, and non-orthodontic applications. Risk of bias was assessed with QUIN tool (in vitro) and RoB-2 (clinical). Of 401 records, 323 remained after removing duplicates; 248 were excluded at title/abstract and 38 at full text, leaving 37 studies (36 in vitro; 1 with an in vitro and clinical component). Seven orthodontic applications were investigated. UA generally provided sufficient bond strength, except on some metal restorations. On enamel, phosphoric-acid etching for 15s improved adhesion. On ceramics, hydrofluoric acid etching (HF) or sandblasting enhanced performance. For polymethyl-methacrylate (PMMA) and composite restorations, bur roughening or sandblasting improved results. UAs may simplify orthodontic bonding across enamel and restorative surfaces without separate primers, but more clinical studies are needed.

PurposeThe increasing use of monolithic translucent zirconia for fixed dental restora-tions in orthodontic patients has created new challenges for reliable bracket bonding. This in vitro study evaluated the influence of different surface pretreatment protocols on the shear bond strength (SBS) of metal brackets bonded to 3-mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) and 5-mol% yttria-stabilized partially stabilized zirconia (5Y-PSZ) ceramics using an adhesive resin cement.Methods and MaterialsNinety-six specimens were prepared (n = 48 per zirconia type), each providing two bonding interfaces (n = 192). Three surface pretreatment protocols were tested: pumice slurry (PS), silicon carbide burr roughening (SiB), and alumina air-particle abrasion (AP). Metal brackets were bonded using an MDP-containing self-adhesive resin cement and a custom 3D-printed bonding device, applying a standardized load of 7.4 N. Half of the specimens were tested for SBS after 3 days of water storage at 37°C; the remaining half after artificial aging (37,500 thermocycles between 5°C and 55°C) for 150 days. SBS was measured using a universal testing machine. Data were analyzed using non-parametric tests (Kruskal–Wallis; Mann–Whitney U with Bonferroni–Holm correction; α = 0.05).ResultsArtificial aging significantly affected SBS, whereas zirconia type had no significant influence. After 3 days, no significant differences were observed among surface pretreatment methods. Following artificial aging, AP and SiB pretreatments achieved significantly higher SBS values than PS for both zirconia types. AP yielded the highest bond strengths overall (up to 51.3 MPa for 5Y-PSZ after 150 days). Spontaneous debonding occurred only in the PS groups.ConclusionAlthough AP pretreatment achieved the highest bond strength values, its clinical application is limited by the risk of surface damage and uncontrollable intraoral pressures. SiB pretreatment provided clinically sufficient bond strength while preserving zirconia surfaces, representing a safer and more practical alternative. Pumice slurry alone was inadequate for reliable bonding. Thus, SiB can be recommended as a minimally invasive and effective clinical protocol for orthodontic bonding to zirconia restorations.

Background: Durable adhesion between orthodontic brackets and enamel is essential for successful fixed orthodontic therapy. Despite simplified adhesive systems being available, conventional etch-and-rinse adhesives remain widely used due to their reliable enamel bonding. Methods: This in vitro study evaluated the bonding performance of three orthodontic adhesive strategies in combination with Transbond XT composite resin for metal bracket fixation. Thirty extracted human premolars were randomly allocated to three groups according to the adhesive system applied: OptiBond Solo Plus (etch-and-rinse method), SafeBond Universal DC (selective enamel etching method) and Transbond XT primer (control method). Shear adhesion resistance, maximum force and breakout force were measured and statistically analysed. Results: No statistically significant differences were observed between the OptiBond and SafeBond groups for any of the evaluated mechanical parameters (p > 0.05), although the OptiBond group exhibited higher mean values. The Transbond XT primer group showed significantly lower adhesion resistance and debonding forces than both of the other groups (p < 0.05). SafeBond demonstrated lower variability of results compared with OptiBond. Conclusions: When used with Transbond XT composite resin, both OptiBond Solo Plus and SafeBond Universal DC provided comparable mechanical performance for metal bracket bonding. While OptiBond yielded higher mean bond strength values, SafeBond exhibited more consistent behaviour. The Transbond XT primer alone resulted in inferior bonding performance.

There is limited evidence regarding the effect of demineralization around orthodontic brackets on shear bond strength (SBS). The aim of this in vitro fatigue study was to evaluate the effect of demineralization developing around orthodontic brackets bonded with different adhesive agents on fatigue-based SBS under laboratory conditions. A total of 60 extracted human maxillary premolars bonded with Gemini metal brackets were randomly allocated into three groups (n = 20). Bracket bonding was performed using Transbond™ XT (acid etching + primer + adhesive) in Group 1, GC Ortho Connect® (acid etching + one-step adhesive) in Group 2, and Transbond™ Plus (self-etch primer + adhesive) in Group 3. The mean demineralization values of the specimens were measured using a DIAGNOdent pen before demineralization (T0) and after 28 days of exposure to an artificial cariogenic environment (T1). Fatigue-based SBS was evaluated under cyclic loading (10N, 0.5Hz) at a crosshead speed of 300mm/min using a low-cycle fatigue testing machine and expressed as the number of shear strokes to failure. The level of statistical significance was set at p < 0.05. There were no significant differences in demineralization values among the groups at either T0 or T1 (p > 0.05). However, all groups showed a significant increase in demineralization at T1 compared with T0 (p < 0.05). Group 2 (GC Ortho Connect®) had a significantly higher number of shear strokes to failure than Groups 1 (Transbond™ XT) and 3 (Transbond™ Plus) (p < 0.05). No significant difference was observed between Groups 1 and 3 (p > 0.05). A significant negative correlation was observed between demineralization and shear strokes to failure across all groups (p < 0.05). Hard tissue (enamel and dentin) damage occurred in nine specimens in Groups 1 and 3, and in seven specimens in Group 2. Increased demineralization may negatively affect fatigue-based SBS and increase the risk of hard tissue damage. Under demineralized conditions, GC Ortho Connect® may demonstrate more favorable fatigue-based bond performance compared with the other adhesive agents evaluated; however, further studies under clinically representative conditions are needed.

Background/Objectives: We evaluated whether resin infiltration treatment of demineralized enamel improves shear bond strength (SBS). Methods: Thirty permanent bovine incisor teeth were assigned randomly into three groups (n = 10 per group): control group, demineralized enamel pretreated with ICON® resin infiltrant (Exp1 group), and demineralized enamel without pretreatment (Exp2). Demineralization was induced using a pH 4.5 solution for 21 days and was monitored using swept-source optical coherence tomography on days 0, 7, 14, and 21. The lesion depth (LD) was quantified and evaluated using ImageJ software. In the Exp1 group, ICON® was applied prior to bracket bonding; no pretreatment was applied in the Exp2 group. In all groups, brackets were bonded using Super-Bond/Clear fluoride-free self-cure adhesive resin (4-META/MMA-TBB, Sun Medical) following Phosphoric acid (65%; Red Activator, Sun Medical). After debonding, enamel surfaces were evaluated to determine the adhesive remnant index (ARI). Results: No significant difference (p = 0.631) was noted in LD between Exp1 and Exp2 groups. The SBS values significantly differed (p < 0.05) between the control (4.1 ± 1.0 MPa) and Exp1 (5.5 ± 1.4 MPa) groups and between the Exp1 and Exp2 (3.8 ± 1.3 MPa) groups. However, SBS did not differ significantly between the control and Exp2 groups. Furthermore, ARI scores showed no significant difference between the control and Exp1 groups, whereas the Exp2 group recorded significantly elevated ARI scores relative to the control group (p = 0.0127). Conclusions: These findings suggest that resin infiltration with ICON® may improve bracket adhesion on demineralized enamel.

AIRC-LABDEN: A multi-modal dataset for dental plaque diagnosis of patients with fixed labial orthodontic appliances