Influence of simulated microwave disinfection on complete denture base adaptation using different flask closure methods

STATEMENT OF PROBLEM: Denture microwave disinfection may result in dimensional changes that may distort the acrylic resin base, causing discomfort to the patient. PURPOSE: The purpose of this study was to determine the effect of simulated microwave disinfection on maxillary denture base adaptation using 2 different flask closure methods. MATERIAL AND METHODS: Forty stone cast-wax base sets were prepared for flasking by the traditional flask closure (TFC) and Restriction System flask closure (RSFC) methods (n=20). The RSFC consists of 2 iron plates to hold the flask during definitive flask closure, maintaining the flask in a closed position after release of pressure. Acrylic resin (Classico) was prepared according to the manufacturer's instructions. After polymerization in water at 74 degrees C for 9 hours, the bases were removed following flask cooling and submitted to conventional finishing with abrasive stones and pumice slurry. Ten bases for each TFC or RSFC method (n=10) were submitted to simulated disinfection (SD) in 150 mL distilled water in a microwave oven at 650 W for 3 minutes; control bases for each TFC or RSFC method (n=10) were not disinfected (ND). Three transverse cuts were made through each stone cast-resin base set, corresponding to the distal of canines, mesial of first molars, and posterior palatal region. Measurements were made in the bases using an optical micrometer at 5 points for each cut to determine adaptation: left and right marginal limits of the flanges, left and right ridge crests, and midline. Collected data were submitted to 3-way ANOVA followed by the Tukey HSD test (alpha=.05). RESULTS: Dimension gap values (mm) for ND denture bases prepared by the RSFC method were significantly lower (0.16 +/- 0.05) when compared to the TFC method (0.21 +/- 0.05) (P<.027). Simulated disinfection statistically improved the base adaptation in bases prepared by the TFC method (0.17 +/- 0.03), compared to the ND bases (0.21 +/- 0.05) (P<.027). Simulated disinfection statistically significantly improved base adaptation (P<.0001) only in the distal of canines (ND=0.13 +/- 0.01; SD=0.11 +/- 0.03) and the posterior palatal region (ND=0.25 +/- 0.04; SD=0.21 +/- 0.01) when bases were prepared by the TFC method. CONCLUSION: Simulated disinfection by microwave energy improved denture base adaptation when the TFC method was used, but did not statistically alter base adaptation for the RSFC method.     

Pathogenic Rickettsia in ticks of spur‐thighed tortoise (Testudo graeca) sold in a Qatar live animal market

The dissemination of vector arthropods harbouring zoonotic pathogens through the uncontrolled transboundary trade of exotic and pet animals poses an important threat to Public Health. In the present report, we describe the introduction of pathogenic Rickettsia africae and R. aeschlimanni in ticks removed from imported tortoises in Qatar. A total of 21 ticks were collected from pet spur‐thighed tortoises (Testudo graeca) from Doha, May 2018, and studied for species identification and characterization of Rickettsia spp. Morphological and molecular analysis of ticks allowed their identification as Hyalomma aegyptium. Molecular analysis of partial ompA and gltA genes showed that Rickettsia sequences found on these ticks clustered with sequences classified as R. aeschilimanii and R. africae. Since pre‐adult stages of H. aegyptium also feed on humans, this tick species may play a role in the transmission of R. aeschilimanii and R. africae. We alert for the introduction of non‐native pets as vehicles for tick importation, known vectors for animal and human pathogenic agents. Importation of exotic species into non‐autochthonous countries deserves strict control to enforce robust surveillance and mitigate potential exotic diseases epidemics.     

Marginal fit and photoelastic stress analysis of CAD-CAM and overcast 3-unit implant-supported frameworks

Statement of problem

Several studies have shown the superiority of computer-assisted design and computer-assisted manufacturing (CAD-CAM) technology compared with conventional casting. However, an advanced technology exists for casting procedures (the overcasting technique), which may serve as an acceptable and affordable alternative to CAD-CAM technology for fabricating 3-unit implant-supported fixed dental prostheses (FDPs).

Anatomical relation between nasal septum deviation and oropharynx volume in different facial patterns evaluated through cone beam computed tomography

Introduction

The objective of this study was to establish the anatomical relation between nasal septum deviation (NSD) and oropharynx volume in different facial patterns using cone beam computed tomography (CBCT).

Methods

Ninety CBCT examinations were analyzed. InVivoDental software was used to evaluate cephalometric image reconstructions in terms of facial type, determined from cephalometric measurements indicative of growth direction; the presence of NSD was also evaluated. ITK-SNAP software was employed for delimitation of the oropharynx. Intra-examiner error methods were recorded. The results were subjected to parametric and non-parametric tests using Bioestat 5.0.

Results

A comparison of facial types revealed a significantly lower prevalence of NSD in the dolichofacial group compared with the brachyfacial and mesofacial groups (P = 0.0101 and 0.0149, respectively). In the total sample, there was a very strong positive relation between the presence of NSD and oropharynx space volume (P = 0.0162). The oropharynx volume was larger in all facial patterns in the presence of NSD.

Conclusion

The presence of NSD was not associated with facial type, although the oropharynx volume in patients with NSD increased. Therefore, deviation of the septum influences oropharynx volume.

     

Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25^+/highCD127^Ø/lowFoxP3⁺, and effector T cells were defined as CD25⁺CD127⁺FoxP3^Ø. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4⁺TREG and CD28⁺TREG cells and an increased frequency of CD40L⁺TREG cells. There was a decrease in the TREG/effector-T ratio for GITR⁺, HLA-DR⁺, OX40⁺, and CD45RO⁺ cells, and an increased ratio of TREG/effector-T CD40L⁺ cells in patients with SLE. In addition, CD40L⁺TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease.     

Applicability of the Appropriate use Criteria for Myocardial Perfusion Scintigraphy

Background

Appropriateness Criteria for nuclear imaging exams were created by American College of Cardiology (ACC) e American Society of Nuclear Cardiology (ASNC) to allow the rational use of tests. Little is known whether these criteria have been followed in clinical practice.

Objective

To evaluate whether the medical applications of myocardial perfusion scintigraphy (MPS) in a private nuclear medicine service of a tertiary cardiology hospital were suitable to the criteria of indications proposed by the American medical societies in 2005 and 2009 and compare the level of indication of both.

Methods

We included records of 383 patients that underwent MPS, November 2008 up to February 2009. Demographic characteristics, patient''s origin, coronary risk factors, time of medical graduation and appropriateness criteria of medical applications were studied. The criteria were evaluated by two independent physicians and, in doubtful cases, defined by a medical expert in MPS.

Results

Mean age was 65 ± 12 years. Of the 367 records reviewed, 236 (64.3%) studies were performed in men and 75 (20.4%) were internee. To ACC 2005, 255 (69.5%) were considered appropriate indication and 13 (3.5%) inappropriate. With ACC 2009, 249 (67.8%) were considered appropriate indications and 13 (5.2%) inappropriate.

Conclusions

We observed a high rate of adequacy of medical indications for MPS. Compared to the 2005 version, 2009 did not change the results.     

Assessing Strategies for Heart Failure with Preserved Ejection Fraction at the Outpatient Clinic

Background:

Heart failure with preserved ejection fraction (HFPEF) is the most common form of heart failure (HF), its diagnosis being a challenge to the outpatient clinic practice.

Objective:

To describe and compare two strategies derived from algorithms of the European Society of Cardiology Diastology Guidelines for the diagnosis of HFPEF.

Methods:

Cross-sectional study with 166 consecutive ambulatory patients (67.9±11.7 years; 72% of women). The strategies to confirm HFPEF were established according to the European Society of Cardiology Diastology Guidelines criteria. In strategy 1 (S1), tissue Doppler echocardiography (TDE) and electrocardiography (ECG) were used; in strategy 2 (S2), B-type natriuretic peptide (BNP) measurement was included.

Results:

In S1, patients were divided into groups based on the E/E''ratio as follows: GI, E/E''> 15 (n = 16; 9%); GII, E/E''8 to 15 (n = 79; 48%); and GIII, E/E''< 8 (n = 71; 43%). HFPEF was confirmed in GI and excluded in GIII. In GII, TDE [left atrial volume index (LAVI) ≥ 40 mL/m²; left ventricular mass index LVMI) > 122 for women and > 149 g/m² for men] and ECG (atrial fibrillation) parameters were assessed, confirming HFPEF in 33 more patients, adding up to 49 (29%). In S2, patients were divided into three groups based on BNP levels. GI (BNP > 200 pg/mL) consisted of 12 patients, HFPEF being confirmed in all of them. GII (BNP ranging from 100 to 200 pg/mL) consisted of 20 patients with LAVI > 29 mL/m², or LVMI ≥ 96 g/m² for women or ≥ 116 g/m² for men, or E/E''≥ 8 or atrial fibrillation on ECG, and the diagnosis of HFPEF was confirmed in 15. GIII (BNP < 100 pg/mL) consisted of 134 patients, 26 of whom had the diagnosis of HFPEF confirmed when GII parameters were used. Measuring BNP levels in S2 identified 4 more patients (8%) with HFPEF as compared with those identified in S1.

Conclusion:

The association of BNP measurement and TDE data is better than the isolated use of those parameters. BNP can be useful in identifying patients whose diagnosis of HF had been previously excluded based only on TDE findings.