Assessment of the cortical bone thickness by CT-scan and its association with orthodontic implant position in a young adult Eastern Mediterranean population: A cross sectional study

Bio-high entropy alloys: Progress, challenges, and opportunities

With the continuous progress and development in biomedicine, metallic biomedical materials have attracted significant attention from researchers. Due to the low compatibility of traditional metal implant materials with the human body, it is urgent to develop new biomaterials with excellent mechanical properties and appropriate biocompatibility to solve the adverse reactions caused by long-term implantation. High entropy alloys (HEAs) are nearly equimolar alloys of five or more elements, with huge compositional design space and excellent mechanical properties. In contrast, biological high-entropy alloys (Bio-HEAs) are expected to be a new bio-alloy for biomedicine due to their excellent biocompatibility and tunable mechanical properties. This review summarizes the composition system of Bio-HEAs in recent years, introduces their biocompatibility and mechanical properties of human bone adaptation, and finally puts forward the following suggestions for the development direction of Bio-HEAs: to improve the theory and simulation studies of Bio-HEAs composition design, to quantify the influence of composition, process, post-treatment on the performance of Bio-HEAs, to focus on the loss of Bio-HEAs under actual service conditions, and it is hoped that the clinical application of the new medical alloy Bio-HEAs can be realized as soon as possible.

Evaluation of the clinical efficacy and safety of modified alveolar cleft bone graft with cone-beam CT digital imaging in children

BACKGROUND

Cone-beam computed tomography (CBCT) is used to observe the bone density and bone height in children with modified alveolar bone graft (ABG) at different times after operation. In this study, the changes of labial-palatal bone mass in the stable period of bone union and in the bone graft area were investigated to provide reference for subsequent treatment.

METHODS

A total of 140 pediatric patients with unilateral complete alveolar cleft were selected and routinely underwent iliac bone grafting. The original data obtained by ProMax 3D (Planmeca) examination were stored in DICOM format at 3 and 6 months postoperatively, and the images were reconstructed by Simplant software (Dentsply Sirona). The bone density of the healthy side was measured at 3 months and 6 months, and the results were expressed as Hounsfield units (HU). The labial and palatal bone height at the bone graft site at 3 and 6 months postoperatively was classified according to the modified Bergland classification method, and was compared with panoramic film classification.

RESULTS

Mean bone density at 3 months after surgery (385.4800±78.39770 HU) was not significantly different from that at 6 months (356.1875±73.67164 HU; P>0.05). There were significant differences between the classification of lip and palatal bone height 3 months after operation and that of the classification of panorama film in the same month (P<0.05); between the classification of lip and palatal bone height 6 months after surgery compared with that of panorama film of the same month (P<0.05); and between the classification of bone height degree in labial, palatal, and panoramic slices at 3 months after operation and that at 6 months after operation (P<0.05).

CONCLUSIONS

The labial and palatal classification is different, and the bone height classification 6 months after surgery is lower than that 3 months after surgery, indicating the persistence of bone resorption. CBCT can objectively evaluate the bone quality in the bone graft area, which has clinical application value for surgical evaluation value and posttreatment guidance.