Zhihua Li

Titanium implants are widely used in dental applications; however, their clinical application is still limited by challenges such as bacterial infection and poor osseointegration. In this study, a composite coating consisting of epigallocatechin-3-gallate (EGCG), hydroxyapatite (HAP), and silver nanoparticles (AgNPs) was fabricated on the titanium surface to improve its antibacterial activity and osteogenic potential. The coating was prepared via alkali-thermal treatment, followed by EGCG adhesion and subsequent deposition of HAP and AgNPs. Surface characterization confirmed successful construction of the coating with improved hydrophilicity. The EGCG/HAP/AgNPs coating showed gradual changes in surface morphology and elemental composition after PBS immersion, suggesting partial coating degradation while retaining detectable residual Ag, Ca, and P on the titanium surface. The coating also exhibited effective antibacterial activity against Staphylococcus aureus and significantly promoted osteogenic differentiation of MC3T3-E1 cells, as evidenced by enhanced alkaline phosphatase activity and mineralized nodule formation. These results demonstrate that the EGCG/HAP/AgNPs composite coating possesses good antibacterial capacity, osteogenic activity, and biocompatibility, showing great potential for improving the clinical performance of titanium implants. The alternative text for this image may have been generated using AI.

Skeletal Class II malocclusion with mandibular retrognathia is a common, condition that can compromise oral function and facial aesthetics. The Herbst appl

This study aimed to compare the skeletal, dentoalveolar, and dental effects of rapid (RME), slow (SME) maxillary expansion, and magnetic maxillary expansion (MME) in adolescents with transverse maxillary deficiency using cone-beam computed tomography (CBCT). A retrospective analysis was conducted on 39 patients (24 males, 15 females; mean age 12.8 ± 0.9 years), equally divided into three groups (N = 13 each) based on the expansion protocol: RME, SME using hyrax expander appliance, or MME. All patients underwent CBCT imaging at baseline (T1), post-expansion (T2), and after a three-month retention period (T3) were extracted. Skeletal, dentoalveolar, and dental parameters, including maxillary basal widths, alveolar inclination, posterior tooth inclination, vertical dental height, and maxillary molar volume, were measured. Statistical analysis was performed using paired t-tests and ANOVA with Tukey’s post-hoc test (p < 0.05). All three protocols produced significant skeletal and dental expansion from T1 to T2 (p < 0.001). RME achieved the greatest skeletal widening, particularly at the nasal floor (p = 0.013), but was associated with more buccal tipping, molar volume reduction, and significantly greater relapse at the nasal floor during retention (p = 0.006). SME provided moderate but stable outcomes with fewer side effects. MME demonstrated skeletal expansion comparable to SME and, in some parameters, to RME, while showing less relapse and smaller reductions in molar volume. Vertical dental height changes were significant across groups. All expansion methods successfully addressed maxillary constriction. RME delivers quick skeletal corrections but presents a higher risk of relapse and dentoalveolar complications. SME yields stable, gradual results, whereas MME shows promise as a viable alternative, offering effective skeletal expansion with fewer negative effects and potential biological benefits.

Objectives: This study aimed to investigate three-dimensional changes in incisive canal (IC) morphology, root–canal proximity, and root resorption following maxillary incisor (U1) retraction with clear aligners, comparing extraction and non-extraction treatment protocols. Materials and methods: A total of 100 patients (200 U1) treated with clear aligners were retrospectively analyzed using CBCT before and after treatment. The extraction group included 40 patients and the non-extraction group 60. Linear measurements of IC width, root–canal distance, cortical bone width (CBW), IC height, and root length/width were obtained at three levels above the labial cementoenamel junction (H1–H3: 2, 4, and 6 mm). Volumetric and surface area analyses of the IC and U1 were performed to evaluate morphological and structural remodeling. Group differences and predictive factors for root resorption and canal contact/invasion were assessed statistically. Results: Extraction-based retraction produced significantly greater reductions in canal width, CBW, and root–canal distance, with increased apical root resorption, most notably in patients who underwent substantial anterior retraction (all P < 0.05). The mean decreases in root–canal distance were 1.08 ± 0.92 mm, 1.10 ± 0.91 mm, and 1.02 ± 0.99 mm at H1, H2, and H3, respectively, in extraction cases, vs. 0.40 ± 0.58 mm, 0.47 ± 0.78 mm, and 0.30 ± 0.98 mm in non-extraction cases. Apical root resorption averaged 0.91 ± 0.80 mm in the extraction group and 0.32 ± 0.56 mm in the non-extraction group ( P < 0.05), correlating with closer root–canal proximity. Volumetric and surface area analyses revealed greater reductions in IC and U1 dimensions in extraction cases, indicating intensified bone remodeling. Treatment duration, incisor movement, IC height, and root–canal distance were significant predictors of canal contact, while root resorption correlated positively with treatment duration, incisor movement, and root length. Conclusion: Extraction-based aligner retraction elicits greater osseous remodeling around the incisive canal and increased root resorption, particularly in cases requiring substantial anterior retraction, reflecting a coupled bone–tooth adaptive response to orthodontic loading. These findings highlight the dynamic nature of craniofacial bone physiology and emphasize the need for biologically guided treatment planning to minimize tissue stress and iatrogenic effects.

Objectives To investigate the impact of three commonly used cleaning methods—mechanical cleaning, chemical cleaning, and ultrasonic cleaning—on the optical transmittance and surface roughness of thermoplastic orthodontic retainers following coffee-induced staining. Materials and methods Standardized thermoplastic specimens were assigned to five groups (n = 10): an unstained control group, a coffee-stained group without cleaning, and three post-staining cleaning groups treated with either mechanical cleaning, chemical cleaning using Polident tablets, or ultrasonic cleaning. Optical transmittance was measured using ultraviolet–visible (UV–Vis) spectrophotometry. Surface roughness parameters (Ra, Rz, RSm) were analyzed via surface profilometer, and surface morphology was examined using scanning electron microscopy (SEM). Results Coffee staining significantly reduced transmittance and increased surface roughness, indicating adverse effects on both optical transmittance and microstructural integrity. Ultrasonic cleaning effectively restored transmittance and surface integrity to near-control levels, with minimal surface damage. Mechanical cleaning successfully removed surface stains but introduced linear abrasions and led to a significant decrease in RSm values. Chemical cleaning achieved moderate stain removal but left visible surface residues. Conclusions Among the cleaning protocols evaluated, ultrasonic cleaning demonstrated superior performance in stain removal and preservation of surface integrity. Mechanical cleaning was effective but caused surface wear, while chemical cleaning offered limited cleaning efficacy and left undesirable deposits. Clinical relevance Cleaning strategies for orthodontic retainers should balance stain removal efficiency with material preservation. Ultrasonic cleaning provides a clinically favorable option, offering effective cleaning with minimal adverse effects on surface characteristics.

Macrophages, one of the key immune cells, are closely associated with various diseases and play critical roles in tissue regeneration via proper polarization. Mesoporous bioactive glass (MBG) has been widely used in bone tissue regeneration; thus, it is charming and beneficial to understand the interactions between MBG and the immune system. Herein, MBG particles with sizes of about 75 nm (MBG-1), 200 nm (MBG-2), and 500 nm (MBG-5) were prepared, and their size effects on macrophage polarization were investigated. The results demonstrated that small MBG particles (75 nm) promoted macrophage polarization toward the M2 phenotype while inhibiting M1 polarization at an early stage (3 days). Meanwhile, medium-sized MBG particles (200 nm) induce a mild inflammatory response in the early stage and promote a high proportion of anti-inflammatory M2 macrophages in the late stage. In contrast, large-sized MBG particles (500 nm) trigger a strong multidirectional activation of macrophages during the early stage, accompanied by a marked upregulation in the expression of both M1 and M2 phenotypic markers. This work preliminarily investigates the relationship between the particle size of MBG and polarization of macrophages, providing insights for the design and further applications of MBG-based biomaterials.

This systematic review and meta-analysis aimed to determine whether the morphology and linear dimensions of sella turcica differ by the different skeletal malocclusions. PubMed, Scopus, EMBASE, and Google Scholar were comprehensively searched for the relevant articles published until 21 May 2024 using combinations of the following terms: sella turcica, lateral cephalometric, skeletal malocclusion, and morphology. Observational studies that assessed sella turcica in different skeletal malocclusions in systemically healthy subjects were included. Data analysis was accomplished using R. Twenty-six studies were included and subjected to quantitative analysis. The length and diameter of sella turcica in Class III were higher compared to Class I [Mean Difference (MD) = 0.42, 95% CI: 0.18–0.67, p value < 0.001; and MD = 0.29, 95% CI: 0.05–0.53, p value = 0.0197, respectively], and compared to Class II (MD = 0.48. 95%CI: 0.23–0.73, p value ≤ 0.001, and MD = 0.4, 95%CI: 0.14–0.65, p value = 0.002, respectively). The depth of sella turcica in Class III was also higher than that of Class II (MD = 0.29, 95%CI: 0.03–0.56, p = 0.03. Furthermore, Class III showed the highest rates of bridge and notch shape of sella turcica compared to Class I (Risk Ratio (RR) = 1.42, 95%CI: 1.13–1.79, p value = 0.0026; and RR = 1.55, 95%CI: 1.11–2.17, p value = 0.011, respectively), and compared to Class II regarding the bridge shape (RR = 1.35, 95%CI: 1.07–1.71, p value = 0.012. The Class III malocclusion showed larger dimensions of sella turcica, and higher prevalence of bridging, notching, and double shape in sella turcica. The present findings do not provide direct diagnostic evidence for orthodontic clinical practice.

This study aimed to compare the effects of clear aligners and fixed appliances on root resorption, incisive canal (IC) morphology, and the spatial relationship between the maxillary central incisors (U1) and the IC following incisor retraction in dental/skeletal Class I and II extraction cases. Sixty-six adult patients (132 maxillary central incisors) with comparable baseline characteristics (based on the ABO Discrepancy Index) were retrospectively analyzed. Patients received either clear aligners (n = 33) or fixed appliances (n = 33) following first premolar extraction. Pre- and post-treatment CBCT measurements were recorded at three vertical reference planes (H1, H2, H3: 2 mm, 4 mm, and 6 mm above the labial cementoenamel junction), including IC width, cortical bone width (CBW), U1–IC distance, IC height, and U1 root length/width. Both groups showed reductions in IC width, CBW, and U1–IC distance, with greater changes in the fixed appliance group. U1–IC distance was significantly reduced in the fixed group at H1 (1.79 ± 0.76 mm vs. 1.24 ± 1.04 mm), H2 (1.78 ± 1.08 mm vs. 1.33 ± 0.86 mm), and H3 (1.61 ± 1.35 mm vs. 1.16 ± 0.90 mm) (P < 0.05). Root resorption was also significantly higher in the fixed group (1.81 ± 1.55 mm vs. 0.87 ± 0.77 mm, P < 0.001). Root–IC proximity patterns included 7.6% separation, 63.1% approximation, 15.9% contact, and 13.4% invasion, with contact and invasion more prevalent in the fixed group. Root resorption increased with IC proximity, peaking at 3.65 ± 1.97 mm in invasion cases. Regression analysis identified tooth movement, root length, and inter-root distance as predictors of U1–IC proximity, while root resorption was associated with treatment duration, U1 movement, IC height, and incisor inclination (U1–SN angle). These findings underscore the importance of individualized planning and appliance selection in cases requiring maximum anterior retraction to reduce the risk of root resorption and IC-related complications.

This study aims to assess morphological changes, the spatial relationship between the maxillary central incisor (U1) and the incisive canal (IC), and root resorption in non-extraction cases treated with either clear aligners or fixed appliances using 3D-CBCT. Two hundred eight maxillary central incisors from 104 patients underwent maxillary incisors retraction without extraction using clear aligners (n = 60) or fixed appliances (n = 44). Measurements, including IC width, root-IC distance, cortical bone width, IC height, and root resorption, were taken before (T1) and after (T2) treatment at specified heights (H1, H2, and H3; 2, 4, and 6 mm above the labial cementoenamel junction of U1). IC width increased with aligners but decreased with fixed appliances, particularly at H1. IC cortical bone width decreased at various levels, with more pronounced reductions at H1 and H3 in the fixed group. The U1 root-IC distance also decreased significantly in both groups, especially in the fixed group at H1 (0.73 ± 0.86 mm vs 0.40 ± 58 mm, P = 0.042), H2 (0.88 ± 0.94 mm vs 0.47 ± 0.78 mm, P = 0.024), and H3 (0.73 ± 0.92 mm vs 0.30 ± 0.98 mm, P = 0.008). Root-IC proximity patterns varied notably, with higher separation rates in the aligner group and greater approximation, contact, and invasion rates in the fixed group. Root resorption was more significant in the fixed group than in the aligner group (1.01 ± 0.74 mm vs 0.32 ± 0.56 mm, P < 0.001). Factors such as treatment duration, U1 movement, and U1-IC distance were identified as primary predictors of root-IC proximity changes. These results highlight the need for careful treatment planning to preserve root health and prevent IC-related risks. Clear aligners may be preferable in non-extraction cases, particularly when the upper incisor is near the IC or requires more retraction, as they could reduce root resorption while maintaining IC dimensions better than fixed appliances.