Bacteriophage Cocktail Can Effectively Control Salmonella Biofilm on Gallstone and Tooth Surfaces

Salmonellosis, which is typically distinguished by an immediate onset of fever, abdominal pain, diarrhea, nausea, and vomiting, is a bacterial infection caused by Salmonella. The rising incidence of antibiotic resistance in Salmonella Typhimurium is a major worldwide problem, and a better knowledge of the distribution of antibiotic resistance patterns in Salmonella Typhimurium is critical for selecting the best antibiotic for infection treatment. In this work, the efficiency of bacteriophage therapy of vegetative cells and biofilms of S. Typhimurium was investigated. Based on their host ranges, five Bacteriophages were chosen for therapy against 22 Salmonella isolates collected from various sources. PSCs1, PSDs1, PSCs2, PSSr1, and PSMc1 phages were found to exhibit potent anti-S. Typhimurium properties. In a 96-well microplate, the efficacy of bacteriophage therapy (105-1011 PFU/mL) against S. Typhimurium biofilm formers was first tested. A bacteriophage treatment (109 PFU/mL) was subsequently applied in the laboratory for 24 hours to minimize Salmonella adhering to the surfaces of gallstones and teeth. In 96-well microplate experiments, bacteriophage treatment inhibited biofilm development and reduced biofilm by up to 63.6% (P ≤ 0.05). When compared to controls, bacteriophages (PSCs1, PSDs1, PSCs2, PSSr1, PSMc1) demonstrated a rapid drop in the populations of S. Typhimurium biofilms generated on the surfaces of gallstones and teeth where the structure of the Salmonella bacteria in the biofilm was broken and holes were created. Clearly, this study indicated that phages might be employed to eliminate S. Typhimurium biofilms on gallstone and tooth surfaces.

Accuracy of different tooth surfaces on 3D printed dental models: orthodontic perspective

Background

Few studies have been reported regarding the accuracy of 3D-printed models for orthodontic applications. The aim of this study was to assess the accuracy of 3D-printed dental models of different tooth surfaces.

Methods

Thirty volunteers were recruited from the hospital, and then their dental models were produced by means of oral scanning and a stereolithography-based 3D printer. Each printed model was digitally scanned and compared with the oral-scanned STL file via superimposition analysis. A color map was used to assess the accuracy of different surfaces (occlusal, buccal, lingual) of anterior and posterior teeth. The Tukey test was used to evaluate the differences between the superimposition.

Results

Statistically significant differences were found in the average deviations of different tooth surfaces (P < 0.05). The mean average absolute deviations of the occlusal surfaces of posterior teeth were greater than those of other surfaces. Percentages of points beyond the upper and lower limits of different tooth surfaces displayed the same results (P < 0.05).

Conclusions

Occlusal surfaces, especially pits and fissures of posterior teeth on 3D printed maxillary dental models, showed greater distortions than those of other teeth and regions.