Incidence of tacrolimus-induced gingival overgrowth in the absence of calcium channel blockers: a short-term study

AIM: The aim of this study was to determine the incidence and severity of gingival overgrowth (GO) induced by tacrolimus (Tcr) compared with ciclosporin A (CiA) in the absence of calcium channel blockers (CCB) in renal transplant recipients. METHODS: Forty patients (20 Tcr and 20 CiA) were evaluated before and 30 and 90 days after kidney transplantation. Demographic (age, gender) and periodontal parameters were recorded for all patients. Patients taking CCB at any time during the study were excluded from the investigation. RESULTS: The mean GO score was significantly lower (p=0.014) in the Tcr group (6.4%) compared with the CiA group (17.9%) after 90 days of immunosuppressive therapy. At 90 days post-transplant, clinically significant GO was observed in four patients of the CiA group and in two of the Tcr group. This difference was not statistically significant (0.66). CONCLUSION: No significant difference in the incidence of clinically significant GO was observed between the CiA and Tcr groups up to 90 days of immunosuppressive therapy.     

The influence of C-factor, flexural modulus and viscous flow on gap formation in resin composite restorations

This study analyzed the influence of C-factor, flexural modulus and viscous flow on gap formation in resin composite restorations. Two resin composites, a mini-filled hybrid (P 60) and a nanofilled (Supreme), were used. The flexural modulus was obtained from bar-shaped specimens submitted to three-point bending. Viscous flow was obtained from the difference between the initial and final diameter of resin composite disks submitted to a load of 10 N for 120 seconds. Gap analysis was conducted in three types of cylindrical cavities (C-factor of 1.8, 2.6 and 3.4) that were prepared on the occlusal surfaces of human molars. The gap width at the dentin-resin composite interface was measured using a 3D scanning system (Talyscan 150). The data were analyzed by ANOVA and Student-Newman-Keuls' test, t-test and linear regression analysis (alpha = 0.05). The cavities with C-factor 3.4 presented the highest Gap formation (p < 0.0001). The lowest Gap formation was found in cavities restored with Supreme resin composite (p < 0.0001). P 60 presented significantly higher flexural modulus and lower viscous flow than Supreme (p < 0.0001). Regression analyses detected a significant influence of flexural modulus and viscous flow on gap formation (p < 0.05).     

Effectiveness of the endotracheal tube cuff on the trachea: physical and mechanical aspects

Introduction

The inflation pressure of the endotracheal tube cuff can cause ischemia of the tracheal mucosa at high pressures; thus, it can cause important tracheal morbidity and tracheal microaspiration of the oropharyngeal secretion, or it can even cause pneumonia associated with mechanical ventilation if the pressure of the cuff is insufficient.

Objective

In order to investigate the effectiveness of the RUSCH® 7.5 mm endotracheal tube cuff, this study was designed to investigate the physical and mechanical aspects of the cuff in contact with the trachea.

Methods

For this end, we developed an in vitro experimental model to assess the flow of dye (methylene blue) by the inflated cuff on the wall of the artificial material. We also designed an in vivo study with 12 Large White pigs under endotracheal intubation. We instilled the same dye in the oral cavity of the animals, and we analyzed the presence or not of leakage in the trachea after the region of the cuff after their deaths (animal sacrifice). All cuffs were inflated at the pressure of 30 cmH₂O.

Results

We observed the passage of fluids through the cuff in all in vitro and in vivo experimental models.

Conclusion

We conclude that, as well as several other cuff models in the literature, the RUSCH® 7.5 mm tube cuffs are also not able to completely seal the trachea and thus prevent aspiration of oropharyngeal secretions. Other prevention measures should be taken.     

Cell sheets of human dental pulp stem cells for future application in bone replacement

Objectives

To analyze the potential of human dental pulp stem cells (hDPSCs) for maintaining their undifferentiated status and osteogenic differentiation capacity when arranged in cell sheets (CSs) for future application in bone replacement.

Materials and methods

CSs were formed after being induced for 10–15 days by clonogenic medium containing additional vitamin C (20 μg/ml). The cell viability of hDPSC4s in the CSs was followed until 96 h using the Live/Dead® assay. The cells of the CSs were enzymatically dissociated and then compared with the original hDPSC4s. The two cell types were characterized immunophenotypically by flow cytometry using specific mesenchymal stem cell-associated markers (CD105, CD146, CD44, STRO-1, and OCT3/4) and non-associated markers (CD34, CD45, and CD14). Osteogenic differentiation was analyzed with the Alizarin red assay.

Results

Living cells were observed until 96 h in the CSs. Both cell types exhibited osteogenic differentiation and expressed the specific undifferentiated MSC-associated markers. Cells spontaneously detached from the CSs attached and proliferated at the bottom of the culture dishes.

Conclusions

Cells in the hDPSC4s cell sheets survived for at least 96 h. Moreover, the cells in the cell sheets retained their stemness and their osteogenic differentiation potential.

Clinical relevance

Cell sheets of hDPSCs could be employed as natural tri-dimensional structures for treating bone loss. This technique would be useful particularly for critical bone defects or any type of bone defects in patients carrying diseases that impair bone regeneration, such as diabetes mellitus, medication-related osteonecrosis of the jaw (MRONJ), and osteoporosis.

     

Differences in Methylmercury and Inorganic Mercury Biomagnification in a Tropical Marine Food Web

Methylmercury (MeHg), inorganic mercury (Hg_inorg) and their biomagnification factors (BMF) were evaluated along a non-degraded Brazilian bay food web. Highly significant differences (p < 0.0001) were found between MeHg and Hg_inorg concentrations among all organisms (microplankton, shrimp, fish and dolphin). MeHg increased with increasing trophic position while Hg_inorg did not present the same pattern. BMF values for MeHg were higher than 1 for all trophic interactions from source to consumer, indicating that MeHg was transferred more efficiently and biomagnified over the entire web. Only one BMF exceeding one was observed for Hg_inorg (27) between microplankton and their consumer, planktivorous fish. BMF values for Hg_inorg were significantly different than those found for MeHg (20) at the base of the food web.