The Protective Role of Front-Closed and Front-Open Gowns Against Staphylococcus Aureus Contamination of Dental Students before and after Restorative Treatments

STATEMENT OF THE PROBLEM

Due to the close contact with patients during dental treatments, dentists and those affiliated to the dental profession are at higher risk for various infections. Infection prevention in dentistry is an important topic that has gained more interest in recent years.

PURPOSE

We aimed to evaluate the protective role of front-closed and front-open gowns against staphylococcus aureus contamination of dental students before and after restorative treatments.

MATERIALS AND METHOD

Sixty male dental students performed the restorative treatments on the teeth of the patients in the front-closed and front-open gowns groups. Before and after the treatment, the wet sterile swab samples were collected from the students' neck and anterior part of the chest. The samples simultaneously cultured on the blood agar and the Staphylococcus-specific medium using spread plate method. Finally, the colonies were counted within 24-48 hours.

RESULTS

The mean of the total colony count increased in both groups of front-open (787.8 ± 88.91) and front-closed gowns (630 ±122.7), but the changes were significant only in the front-open gown group (p≤ 0.001). Compared to the front-closed gown group (430±71.08), the total colony count of staphylococcus aureus in the front-open gown group (490.3±62.5) was increased significantly (p≤ 0.001).

CONCLUSION

We confirmed that dental students occupationally exposed to the bacterial agents and even simple minor changes in gown could considerably decrease the contamination. Education about bacterial transmission, as well as infection prevention and control measures is necessary for dental students, especially when they participate in clinical practice.

Comparison of two digestion strategies on characteristics and differentiation potential of human dental pulp stem cells

OBJECTIVE

This study aimed to compare the behavior of dental pulp stem cells (DPSCs) after isolation using solutions containing either collagenase/dispase or collagenase alone.

DESIGN

DPSCs were isolated by two digestion methods (collagenase/dispase or collagenase alone) from human third molars. Immunophenotypic features were confirmed by flow cytometry for cell markers STRO-1, cluster of differentiation (CD) 146, CD45, and collagen type-I. The proliferation potential of cells was evaluated by 5-bromo-2'-deoxyuridine (brdU) incorporation assay, and finally they were assessed for multi-lineage differentiation potential. Data were analyzed using one-way analysis of variance and independent t-tests.

RESULTS

DPSCs isolated by either method showed similar levels of STRO-1, CD45, and collagen type-I and similar incorporation of brdU (P > 0.05). However, DPSCs obtained by collagenase I/dispase treatment had significantly higher numbers of CD146⁺ cells and osteogenic and chondrogenic capacities compared to those obtained by treatment with collagenase I alone (P < 0.05). On the other hand, more STRO-1+/CD164-DPSCs were found in the collagenase alone group with higher adipogenic potential.

CONCLUSIONS

Different enzyme solutions gave rise to different populations of DPSCs. Dispase enhanced isolation of CD146⁺ DPSCs probably by disrupting the basement membranes of blood vessels and releasing DPCSs embedded in the perivascular niche. Furthermore, the differentiation potential of DPSCs was influenced by the change in enzyme solution.