SrCuSi4 O10 /GelMA Composite Hydrogel-Mediated Vital Pulp Therapy: Integrating Antibacterial Property and Enhanced Pulp Regeneration Activity

Vital pulp therapy (VPT) is considered a conservative treatment for preserving pulp viability in caries-induced dental pulp infections. However, bacterial contamination negatively affects dentine-pulp complex repair. The common capping materials show limited antimicrobial effects against some microorganisms. To improve the VPT efficacy, capping materials with increased antibacterial properties and enhanced odontogenic and angiogenic activities are needed. Herein, a SrCuSi4 O10 /gelatin methacrylate(SC/Gel) composite hydrogel has been proposed for infected dental pulp treatment. SrCuSi4 O10 (SC) is a microscale bioceramic composed of assembled multilayered nanosheets that possesses good near-infrared photothermal conversion ability and multiple bioactivities due to sustained Sr2+ , Cu2+ , and SiO3 2- ion release. It is shown that the SC/Gel composite hydrogel efficiently eliminates Streptococcus mutans and Lactobacillus casei and inhibits biofilm formation under photothermal heating, while the ion extract from SC promotes odontogenesis of rat dental pulp stem cells and angiogenesis of human umbilical vein endothelial cells. The as-designed therapeutic effect of SC/Gel composite hydrogel-mediated VPT has been proven in a rat dental pulp infection model and yielded improved dentine-pulp complex repair compared with the commercially used iRoot® BP Plus. This study suggests that the SC/Gel composite hydrogel is a potential pulp-capping material with improved effects on dentine-pulp complex repair in infected pulp.

Endodontic management of a three-rooted maxillary premolar: A case report

Maxillary premolars exhibit anatomical variations in the numbers of roots and canals, which pose a challenge during root canal therapy. In the present case report, we describe the endodontic management of a three-rooted maxillary premolar. A 47-year-old Yamani man was referred to the College of Dentistry, Taibah University for endodontic treatment of his right maxillary first premolar (#14). Periapical diagnostic radiography did not provide adequate information about the morphology of the root canal system and number of roots. Subsequently, a 3D cone-beam computed tomographic (CBCT) image was obtained, which revealed three roots in the aforementioned premolar. Root canal treatment was performed under magnification using a dental operating microscope, R25 RECIPROC blue NiTi single file system, and the Calamus dual 3-D obturation system. Clinicians should be able to predict the anatomical variations in maxillary premolars and have adequate knowledge and skills for managing such situations.

Endotracheal tube biofilm and ventilator-associated pneumonia with mechanical ventilation

OBJECTIVE

To analyze biofilm on internal and external surfaces of endotracheal tubes after their use in critical care patients, and to produce evidence of association between use of the tube, presence of biofilm, and the occurrence of pneumonia.

METHODS

This was a clinical study performed at the Intensive Care Unit of an emergency hospital in the interior of São Paulo state, Brazil. Data collection involved 30 endotracheal tubes used on adult patients for a period of ≥48 h of mechanical ventilation for scanning electron microscopy.

RESULTS

Analysis of the biofilm on the 30 tubes by scanning electron microscopy showed various abiotic and biotic structures, predominantly on the internal surface, such as: fibrin network, erythrocytes, leukocytes, cocci, bacilli, and molds, among others. The intubation period of the endotracheal tube for ≥8 days represented one of the risk factors for ventilator-associated pneumonia (RR 7.41, P < 0.001).

CONCLUSIONS

The presence of the endotracheal tube permits microbial colonization, overall contributing to the development of biofilm and the occurrence of pneumonia.