Kappa-carrageenan based hybrid hydrogel for soft tissue engineering applications.

Biological materials such as cell-derived membrane vesicles have emerged as alternative sources for molecular delivery systems, owing to multicomponent features, the inherent functionalities and signaling networks, and easy-to-carry therapeutic agents with various properties. Herein, red blood cell membrane (RBCM) vesicle-laden methacrylate kappa-carrageenan (KaMA) composite hydrogel is introduced for soft tissue engineering. Results revealed that the characteristics of hybrid hydrogels were significantly modulated by changing the RBCM vesicle content. For instance, the incorporation of 20% (v/v) RBCM significantly enhanced compressive strength from 103 ± 26 kPa to 257 ± 18 kPa and improved toughness under the cyclic loading from 1.0 ± 0.4 kJ m-3to 4.0 ± 0.5 kJ m-3after the 5thcycle. RBCM vesicles were also used for the encapsulation of curcumin (CUR) as a hydrophobic drug molecule. Results showed a controlled release of CUR over three days of immersion in PBS solution. The RBCM vesicles laden KaMA hydrogels also supportedin vitrofibroblast cell growth and proliferation. In summary, this research sheds light on KaMA/RBCM hydrogels, that could reveal fine-tuned properties and hydrophobic drug release in a controlled manner.

Electrochemical corrosion assessment of RaCe and Mtwo rotary nickle-titanium instruments after clinical use and sterilization.

AIM: The aim of the present study was to electrochemically evaluate corrosion resistance of RaCe and Mtwo files after repeated sterilization and preparation procedures. STUDY DESIGN: A total of 450 rotary files were used. In the working groups, 72 files from each file type were distributed into 4 groups. RaCe and Mtwo files were used to prepare one root canal of the mesial root of extracted human mandibular first molars. The procedure was repeated to prepare 2 to 8 canals. The following irrigation solutions were used: group 1, RaCe files with 2.5% NaOCl; group 2, RaCe files with normal saline; group 3, Mtwo files with 2.5% NaOCl; and group 4, Mtwo files with normal saline in the manner described. In autoclave groups, 72 files from each file type were evenly distributed into 2 groups. Files were used for a cycle of sterilization without the use of files for root canal preparation. Nine new unused files from each file type were used as controls. Then the instruments were sent for corrosion assessment. Mann-Whitney U and Wilcoxon tests were used for independent and dependent groups, respectively. RESULTS: Statistical analysis indicated that there were significant differences in corrosion resistance of files associated with working and autoclave groups between RaCe and Mtwo file types (p<0.001). CONCLUSIONS: Corrosion resistance of #25, #30, and #35 Mtwo files is significantly higher than that in RaCe files with similar sizes.

[Oral surgery in hemophilia patients]. / Bloedige orale ingrepen bij patiënten met hemofilie.

Oral surgery in hemophilia patients requires special arrangements in close collaboration with a hemotologist. Minor oral surgeries in not complicated cases can be done by a dentist or an oral surgeon with aid and assistance of a hemotologist. All major oral surgeries in hemophilia patients with antibodies counteracting coagulation agents should occur in a hemophilia treatment centre.

The natural course of an ossifying fibroma. A case report.

A patient with an ossifying fibroma in the mandible is presented, with a follow-up period of 38 years. The pathological findings and recommendations for therapy are discussed.

The value of long-term follow-up of mandibular advancement surgery in patients with a low to normal mandibular plane angle.

The objective of this study was to evaluate retrospectively the stability of mandibular advancement via bilateral sagittal split osteotomies. Two fixation methods were compared: intermaxillary fixation (IMF) and rigid internal fixation (RIF). The hypothesis was that, in patients with a low to normal mandibular plane angle (MPA) in retrognathia, the bilateral sagittal split osteotomy (BSSO) to advance the mandible is a predictable and stable procedure and that no significant changes occur after 1 year. Twelve patients with mandibular deficiency with a low to normal MPA (mean 24.7 degrees, range 20.3 degrees-30.7 degrees) underwent BSSO with IMF. The follow-up period was at least 5 years (mean 6.3, range 5-9.1 years). Cephalometric analysis using a commercial software package was performed on radiographs that were taken immediately preoperatively (T0), within 6 weeks postoperatively (T1), 1 year postoperatively (T2), and at least 5 years postoperatively (T3). The average advancement at B point was 4.7 mm (range: 3-7 mm). The assessment of B point in regard to relapse showed no significant change. One patient showed a relapse due to condylar resorption. Forty-five consecutive patients were treated with RIF. Radiographs were taken preoperatively (T0), 6 weeks postoperatively (T1), and 1 year postoperatively (T2). This group had a mean MPA of 26.2 degrees, range 10 degrees-32 degrees. The average B-point advancement was 4.4 mm (range 1-10 mm). No patient showed a clinically significant relapse at T2.