Effect of fence tray matching care on excess adhesive and bracket placement accuracy for orthodontic bonding: an in vitro study.

OBJECTIVE: This study aimed to evaluate the effect of fence tray matching care (FTMC) in bracket bonding by measuring excess adhesive, as well as linear and angular deviations, and by comparing it with the half-wrapped tray (HWT). MATERIALS AND METHODS: An intraoral scanner was used to acquire data on the maxillary dental arch of a patient with periodontitis.Furthermore, 20 maxillary dental arch models were 3D printed. Using 3Shape, PlastyCAD software, and 3D printing technology, 10 FTMC (method I) and HWT (method II) were obtained. By preoperative preparation, intraoperative coordination, and postoperative measurement, the brackets were transferred from the trays to the 3D-printed maxillary dental arch models. Additionally, the bracket's excess adhesive as well as linear and angular deviations were measured, and the differences between the two methods were analyzed. RESULTS: Excess adhesive was observed in both methods, with FTMC showing less adhesive (P< 0.001), with a statistical difference. Furthermore, HWT's vertical, tip and torque, which was significantly greater than FTMC (P< 0.05), with no statistical difference among other respects. The study data of incisors, canines, and premolars, showed that the premolars had more adhesive residue and were more likely to have linear and angular deviations. CONCLUSIONS: The FTMC had higher bracket bonding effect in comparison to HWT, and the adhesive residue, linear and angular deviations are smaller. The fence tray offers an intuitive view of the precise bonding of the bracket, and can remove excess adhesive to prevent white spot lesions via care, providing a different bonding method for clinical applications.

Study on the application of quality control circle activity in postoperative nursing of elderly dental implants.

BACKGROUND: To explore the application effect of "quality control circle" activity in postoperative nursing of elderly dental implants. METHODS: From January 2022 to December 2022, a total of 60 elderly patients were selected and divided into an experimental group and a control group, with 30 cases in each group using the random number table method. The elderly patients with dental implants received postoperative care under the supervision of a quality control circle. The control group was treated with conventional nursing methods. The success rate, postoperative complications, and satisfaction of the 2 groups were compared. RESULTS: By comparing the postoperative care effect of the 2 groups of patients, the satisfaction of the experimental group and the control group was 93.3% and 73.3%, respectively, showing the satisfaction of the experimental group was higher than the control group (P < .05). The planting success rate of the experimental and control groups were 96.7% and 66.7%, respectively, with the experimental group outperforming the control group (P < .05). The proportion of complications in the experimental was found to be fewer (6.7%) than in the control group (33.3%) (P < .05). CONCLUSION: Quality control circle activities can effectively improve the success rate of dental implants, reduce the occurrence of postoperative complications, improve patient satisfaction, and help medical staff in providing better treatment for patients.

Accuracy of Microimplant Placement Using a 3D Guide Plate for Orthodontic Anchorage.

This study aimed to design a three-dimensional (3D) guide plate using computer-aided design and a 3D printing system for precise implantation of microimplants for orthodontic treatment and investigate the accuracy and feasibility of a 3D guide plate in clinical practice. A total of 30 microimplants were placed in 15 patients in the Department of Stomatology, Affiliated Hospital of Jiangnan University. Before surgery, DICOM data from cone-beam computed tomography (CBCT) scans and STereoLithography data from the 3D model scan were imported to 3Shape Dental System. Data fitting and matching were performed, and 3D guide plates were designed primarily focusing on the thickness of guide plates, amount of concave compensation, and dimensions of the ring. Assist implantation method was used to place the microimplants, and postoperative CBCT images were used to evaluate the position and implantation angle. The feasibility of placing microimplants and precise implantation guided by the 3D guide plate. CBCT data before and after the placement of microimplants were compared. Regarding the secure positioning of microimplants based on CBCT data, 26 implants were categorized as Grade i, four as Grade ii, and none as Grade iii. No loosening of microimplants 1 and 3 months after surgery was reported. The implantation of microimplants is more accurate under the guidance of a 3D guide plate. This technology can achieve accurate implant positioning, thus ensuring safety, stability, and improved success rates after implantation.

Transhemispheric cortex remodeling promotes forelimb recovery after spinal cord injury.

Understanding the reorganization of neural circuits spared after spinal cord injury in the motor cortex and spinal cord would provide insights for developing therapeutics. Using optogenetic mapping, we demonstrated a transhemispheric recruitment of neural circuits in the contralateral cortical M1/M2 area to improve the impaired forelimb function after a cervical 5 right-sided hemisection in mice, a model mimicking the human Brown-Séquard syndrome. This cortical reorganization can be elicited by a selective cortical optogenetic neuromodulation paradigm. Areas of whisker, jaw, and neck, together with the rostral forelimb area, on the motor cortex ipsilateral to the lesion were engaged to control the ipsilesional forelimb in both stimulation and nonstimulation groups 8 weeks following injury. However, significant functional benefits were only seen in the stimulation group. Using anterograde tracing, we further revealed a robust sprouting of the intact corticospinal tract in the spinal cord of those animals receiving optogenetic stimulation. The intraspinal corticospinal axonal sprouting correlated with the forelimb functional recovery. Thus, specific neuromodulation of the cortical neural circuits induced massive neural reorganization both in the motor cortex and spinal cord, constructing an alternative motor pathway in restoring impaired forelimb function.

Melatonin prevents peri­implantitis via suppression of TLR4/NF-κB.

Peri­implantitis, which is characterized by peri­implant mucositis and alveolar bone resorption, significantly shortens the service life of dental implants. Melatonin is well-known for its anti-inflammatory and osteoprotective activities. Nevertheless, the effects and mechanisms of melatonin to prevent peri­implantitis remain unknown. In this study, the lipopolysaccharide-induced peri­implantitis model was established after the titanium implants were osseointegrated, and the rats received daily administrations of melatonin. The gingival fibroblasts and osteoclasts/osteoblasts were also co-cultured to simulate the inflammatory environment in vitro. We found that prophylactic administration of melatonin decreased proinflammatory cytokine levels and osteoclast numbers, attenuated alveolar bone resorption, and reduced the incidence of peri­implantitis in vivo. Furthermore, melatonin suppressed osteoclastic formation and function in the inflammatory co-culture environment, while melatonin promoted osteoblastic differentiation and function in the in vitro model. Mechanistically, melatonin reduced TLR4 protein levels, and inhibited activation of NF-κB to downregulate the levels of TNF, IL-1ß, and IL-6. These data showed that melatonin was a potent agent to prevent peri­implantitis through inhibiting TLR4/NF-κB signaling. Our findings provide a novel strategy to prevent peri­implantitis, and expand the applications of melatonin. STATEMENT OF SIGNIFICANCE: Dental implants have become the first choice for restoring partial and full edentulism, but its service life is seriously affected by peri­implantitis. Exploration of novel and effective approaches to prevent peri­implantitis is an important and urgent need. In the present study, we have reported for the first time that prophylactic administration of melatonin delayed the occurrence and reduced the incidence of peri­implantitis by decreasing proinflammatory cytokine levels, inhibiting osteoclastogenesis, and promoting osteogenesis. The study is expected to have an important significance on the prevention of peri­implantitis.

Expression of murine ELL-associated factor 2 (Eaf2) is developmentally regulated.

Eaf2, ELL-associated factor 2, encodes a protein that is homologous to the human EAF1, which was shown to interact with the transcriptional elongation factor MEN/ELL. During mouse embryogenesis, Eaf2 is preferentially expressed in the central nervous system and in sensory and neuroendocrine organs, including the brain, spinal cord, cranial and spinal ganglia, developing otocyst, the retina, and the pituitary. Eaf2 transcripts were also found in sites where active epithelium-mesenchymal interactions are occurring. These included the invaginating tooth buds, mammary gland anlage, submandibular glands, the lung, the pancreas, and the kidney. Other sites of expression included bladder and intestine. In the developing lens, Eaf2 transcripts were absent in the proliferating anterior lens epithelial cells but were present in the terminally differentiated primary lens fiber cells and also in nonproliferating lens fiber cells in the equatorial zone where lens epithelial cells withdraw from cell cycle and terminally differentiate into secondary lens fiber cells. This spatially restricted pattern of Eaf2 expression in the developing lens suggests that Eaf2 may play an important role in regulating lens maturation.