Search

Background Phosphate-based glass (PBG) is an attractive bioactive material for promoting the cellular regenerative response. PBG consists of glass network which contains phosphate as the main component and can be substituted into various therapeutic ions. Strontium (Sr) can stimulate osteogenic activity and inhibit the pro-inflammatory response. However, there are limited studies on the characterization and biological performance Sr-substituted PBG (PSr). In this study, PSr was characterized and its of immuno-osteogenic response potential was investigated for substituting Ca with Sr. Considering a priority for cellular activity, we compared the optimized PSr against the benchmark 45S5 bioactive glass (BG) for its effect on cellular bioactive response and regenerative hard tissue. Methods PSr groups were fabricated by a melt-quenching method; subsequently, they were characterized and their biological performance was investigated for the preference of PSr. Considering the clinically used BG as the benchmark, PSr was evaluated based on the cytotoxicity assay, osteogenic activity, pro-inflammatory response, and implantation of calvaria bone defect. Results PSr groups exhibited a glass structure and phosphate network similar to that of PBG. However, the results of ion release analysis showed that PSr6 was stable in accordance with Ca/P, Ca/Sr, and P/Sr ratios. Based on these results, the cellular response of PSr6 was the highest, which increased for the early osteogenic marker and inhibited the inflammatory response. Compared to the clinically used BG as the benchmark, PSr6 promoted osteogenic activity and suppressed inflammatory response. The results of in vivo study indicated that the new bone formation in the PSr6 was similar to that in benchmark BG. However, the limitation of this study was the four weeks of implantation. However, the results of our study suggest that PSr6 is promising for enhancing the immuno-osteogenic response and regenerating hard tissue with the optimized glass structure having Ca/Sr ratio of 2:1. Conclusions The developed PSr6 demonstrated stable physical properties, favorable cytocompatibility, and immune-osteogenic response. Compared with benchmark BG, PSr6 exhibited enhanced immuno-osteogenic response and regeneration of new bone and connective tissues. Therefore, PSr6 is a potential bone grafting material for regenerative hard tissue.

The present study aimed to compare the thickness, gap width, and translucency of 3D-printed and thermoformed clear aligners using micro-computed tomography (micro-CT). Four groups of clear aligners were tested: thermoformed with single-layer material (TS, polyethylene terephthalate glycol) or a multi-layer material (TM, copolyester-elastomer combination), and 3D-printed TC-85 cleaned with alcohol (PA) or with centrifuge (PC). Aligners (n=10) were fitted onto respective models and micro-CT was performed. Thickness and gap width were measured for different tooth type in sagittal sections on all sides. CIELab coordinates were measured (n=5) to compare the translucency. Depending on tooth type and location, thermoformed and 3D-printed clear aligners have significantly varied thicknesses and showed a clinically acceptable range of fit with differences in regions of best fit. Centrifugation in post-processing significantly improved the translucency of 3D-printed aligners.

Low dose and accessibility have increased the application of cone beam computed tomography (CBCT). Often serial images are captured for patients to diagnose and plan treatment in the craniofacial region. However, CBCT images are highly variable and lack harmonious reproduction, especially in the head's orientation. Though user-defined orientation methods have been suggested, the reproducibility remains controversial. Here, we propose a landmark-free reorientation methodology based on principal component analysis (PCA) for harmonious orientation of serially captured CBCTs. We analyzed three serial CBCT scans collected for 29 individuals who underwent orthognathic surgery. We first defined a region of interest with the proposed protocol by combining 2D rendering and 3D convex hull method, and identified an intermediary arrangement point. PCA identified the y-axis (anterioposterior) followed by the secondary x-axis (transverse). Finally, by defining the perpendicular z-axis, a new global orientation was assigned. The goodness of alignment (Hausdorff distance) showed a marked improvement (> 50%). Furthermore, we clustered cases based on clinical asymmetry and validated that the protocol was unaffected by the severity of the skeletal deformity. Therefore, it could be suggested that integrating the proposed algorithm as the preliminary step in CBCT evaluation will address a fundamental step towards harmonizing the craniofacial imaging records.

Orthodontic facemask is an extraoral orthodontic appliance used in children with skeletal Class III malocclusion to influence the maxillary and mandibular developments in a favorable direction. While the use of facemask is the most effective in patients before the growth peak, skin irritation is often observed during the treatment. Thus, the present retrospective study aimed to investigate the prevalence and pattern of such skin changes and distinguish the possible factors associated with them. Patient age and sex; orthodontic parameters, expressing the severity of malocclusion; the presence of complaints in the temporomandibular joint (TMJ) areas; and the level of patient cooperation were evaluated. Additionally, in patients with skin reactions the severity and onset time were further analyzed. The results indicated that 43.5% of the patients experienced skin changes, which were characteristic for irritant contact dermatitis. The presence of TMJ complaints, and female sex were found to have a statistically significant correlation with the occurrence of skin irritation. Furthermore, skin irritation was observed more frequently in younger patients. Clinicians should give a particular attention to the skin areas, which come in contact with the appliance at every visit in order to detect any potential problems. Moreover, patients and parents should be provided with sufficient information, regarding the possibility, prevention and management of skin problems during facemask therapy.

ObjectivesThe use of 16S ribosomal RNA gene sequencing analyses has rapidly increased in clinical oral studies. However, cohort-based clinical research has not sufficiently accounted for the periodic stability in oral microbiota. Herein, we aimed to assess the stability of the oral microbiome across time from an intervention-free “healthy” cohort. Materials and MethodsWe obtained 33 supragingival samples of 11 healthy participants from the biobank. For each participant, we processed one sample as baseline (T0) and two samples spaced at monthly (T1) and quarterly (T2) intervals for 16S ribosomal RNA gene sequencing analysis. ResultsWe observed that taxonomic profiling had a similar pattern of dominant genera, namely Rothia, Prevotella, and Hemophilus, at all-time points. Shannon diversity revealed a significant increase from T0 (pp

Colonization of auto-polymerized acrylic resin by pathogenic Candida albicans is a common problem for denture users. In this study, zinc-modified phosphate-based glass was introduced into an auto-polymerized acrylic resin at concentrations of 3, 5, and 7 wt.%. The mechanical or physical properties (flexural strength, elastic modulus, microhardness, and contact angle), surface morphology of the resultant materials, and the antimicrobial effect on C. albicans were investigated. There were no statistical differences in the mechanical properties between the control and the zinc-modified phosphate-based glass samples (p > 0.05); however, the number of C. albicans colony-forming units was significantly lower in the control group (p C. albicans tended not to adhere to the zinc-modified-phosphate-based glass samples. Thus, the zinc-modified materials retained the advantageous mechanical properties of unaltered acrylic resins, while simultaneously exhibiting a strong antimicrobial effect in vitro.

This study aimed to classify the radiographical characteristics of impacted maxillary canines that were surgically exposed followed by orthodontic traction and to investigate the correlation between these characteristics and the traction duration for impacted maxillary canines. This retrospective study enrolled 74 patients with 87 maxillary canines. Cone beam computed tomography images, panoramic radiographs, and medical records were analyzed. Cyst formation and resorption of adjacent roots were observed in 26.4% and 23.0% of cases, respectively. Impacted maxillary canines were mostly distributed in the lateral incisor area. The average traction duration for 47 teeth that met the study criteria was 13.9±8.9 months. The distance from the maxillary canines to the occlusal plane (3c-OP) and to the midline and the angle between the midline and maxillary canines showed a statistically significant correlation with traction duration (p

Background This prospective randomized clinical trial aimed to evaluate the immediate and short-term skeletal, dentoalveolar, and periodontal effects of rapid palatal expansion (RPE) and miniscrew-assisted RPE (MARPE) in adolescent and young adult patients. Methods This study followed a two-arm, parallel, randomized clinical trial design that recruited patients with transverse maxillary deficiency in a 1:1 allocation ratio. Forty patients (14 men and 26 women) requiring maxillary expansion were randomly allocated to the RPE (n = 20, age = 14.0 ± 4.5) or MARPE (n = 20, age = 14.1 ± 4.2) groups. The assignment was performed via computer-generated block randomization, with a block size of four. Upon identical (35 turns) amount of expansion, low-dose cone-beam computed tomography images were taken before treatment (T0), immediately after expansion (T1), and after a 3-month consolidation period (T2). The primary outcome of this study comprised the assessment of midpalatal suture separation. Secondary outcomes included, skeletal, dentoalveolar, and periodontal measurements, which were performed at each time point. Results The frequency of midpalatal suture separation was 90% (18/20) and 95% (19/20) for the RPE and MARPE groups, respectively. A greater increase in nasal width in the molar region (M-NW) and greater palatine foramen (GPF) was observed immediately after the expansion (T1-T0) and consolidation periods (T2-T0) in the MARPE group compared to the RPE group (P P P Conclusions Midpalatal suture separation was observed in 90% and 95% of patients in the RPE and MARPE groups, respectively. Both RPE and MARPE groups exhibited significant triangular basal bone expansion and skeletal relapse during consolidation. Under identical amounts of expansion, the MARPE group showed lower decrease in the skeletal, dentoalveolar and periodontal variables after consolidation. The reinforcement of RPE with miniscrews contributes to the maintenance of the basal bone during consolidation period. Trial registration WHO Institutional Clinical Trials Registry Platform (IRB No. KCT0006871 / Registration date 27/12/2021).

To elucidate genetic factors affecting orthodontic treatment duration, we employed targeted next-generation sequencing on DNA from the saliva of 117 patients undergoing orthodontic treatment after premolar extraction. The clinical characteristics of patients were summarized, and the association of clinical variables with treatment duration was assessed. Patients whose treatment duration deviated from the average were classified into an extreme long group or an extreme short group. We identified single nucleotide polymorphisms (SNPs) significantly enriched in the two groups via targeted sequencing. Nine SNPs (six genes) were significantly enriched in both groups. In the extreme long group, the frequency of the CC genotypes of WNT3A, SPP1 (rs4754, rs9138), and TNFSF11, the TT genotype of SPP1 (rs1126616), as well as the GG genotype of SFRP2 was significantly higher than in the short group. In the extreme short group, the TC genotype of SPP1, the AA genotype of P2RX7, the CT genotype of TNFSF11, and the AG genotype of TNFRSF11A tended to exhibit higher frequency than in the long group. Taken together, we identified genetic polymorphisms related to treatment duration in Korean orthodontic patients undergoing premolar extraction. Accurate prediction of the treatment period through further research will be of great aid to patients as well as orthodontists.