Knowledge and awareness of polycaprolactone and its applications as provisional material in prosthodontic practice: A questionnaire-based survey

Aim

The present study was done to evaluate the knowledge and awareness of different provisional materials, especially polycaprolactone (PCL) and their application in prosthodontic practice.

Setting and Design

A questionnaire based survey was carried out to assess the knowledge and awareness of PCL and its applications as provisional material in prosthodontic practice.

Materials and Method

A questionnaire-based descriptive study consisting of 10 questions related to different provisional materials and their applications in prosthodontic practice was formulated on Google Forms. The link was created and circulated among the prosthodontist faculty members of various dental institutes and private practitioners of India with the use of digital platforms such as E-mail and social media. The data were collected and examined using Microsoft Excel software for statistical evaluation.

Statistical Analysis Used

For this descriptive type of study, knowledge and awareness among prosthodontists across India was evaluated using Microsoft Excel software.

Results

The use of PCL was known only to 20.75% of prosthodontists. Moreover, its application and indications are known to only <1% of the study participants. Autopolymerizing resin was most commonly used for the custom tray and temporary base fabrication as well as temporization in crown and bridge prosthesis, while muscle deprogrammer and surgical template were commonly fabricated in heat-cure and clear acrylic resin, respectively. Pattern resin was found to be commonly used in splinting implant impression copings.

Conclusion

The use of PCL as a temporary denture base, custom tray, muscle deprogrammer, implant impression splinting, and provisional for crown and bridge and templates should be encouraged and incorporated to get benefits of its characteristic properties. Considering the overall performance of PCL, its use should be incorporated into prosthodontic research and practice.

Testing the photon-number statistics of a quantum key distribution light source

A commonly held tenet is that lasers well above threshold emit photons in a coherent state, which follow Poissonian statistics when measured in photon number. This feature is often exploited to build quantum-based random number generators or to derive the secure key rate of quantum key distribution systems. Hence the photon number distribution of the light source can directly impact the randomness and the security distilled from such devices. Here, we propose a method based on measuring correlation functions to experimentally characterize a light source's photon statistics and use it in the estimation of a quantum key distribution system's key rate. This promises to be a useful tool for the certification of quantum-related technologies.

Type 1 Diabetes Genetic Risk Score: A Novel Tool to Discriminate Monogenic and Type 1 Diabetes

Distinguishing patients with monogenic diabetes from those with type 1 diabetes (T1D) is important for correct diagnosis, treatment, and selection of patients for gene discovery studies. We assessed whether a T1D genetic risk score (T1D-GRS) generated from T1D-associated common genetic variants provides a novel way to discriminate monogenic diabetes from T1D. The T1D-GRS was highly discriminative of proven maturity-onset diabetes of young (MODY) (n = 805) and T1D (n = 1,963) (receiver operating characteristic area under the curve 0.87). A T1D-GRS of >0.280 (>50th T1D centile) was indicative of T1D (94% specificity, 50% sensitivity). We then analyzed the T1D-GRS of 242 white European patients with neonatal diabetes (NDM) who had been tested for all known NDM genes. Monogenic NDM was confirmed in 90, 59, and 8% of patients with GRS <5th T1D centile, 50-75th T1D centile, and >75th T1D centile, respectively. Applying a GRS 50th T1D centile cutoff in 48 NDM patients with no known genetic cause identified those most likely to have a novel monogenic etiology by highlighting patients with probable early-onset T1D (GRS >50th T1D centile) who were diagnosed later and had less syndromic presentation but additional autoimmune features compared with those with proven monogenic NDM. The T1D-GRS is a novel tool to improve the use of biomarkers in the discrimination of monogenic diabetes from T1D.

A comparative evaluation of bond strength of feldspathic porcelain to nickel-chromium alloy, when subjected to various surface treatments: An in vitro study

Purpose of the Study:

The purpose was to evaluate the effect of various surface treatments and sandblasting with different particle size on the bond strength of feldspathic porcelain with predominantly base metal alloys, using a universal testing machine.

Materials and Methods:

Totally, 40 specimen of nickel-chromium alloy were prepared in an induction casting machine. The groups divided were as follows: Group I-sandblasted with 50 μ Al₂O₃, Group II-sandblasted with 110 μ Al₂O₃, Group III-sandblasted with 250 μ Al₂O₃ and Group IV-sandblasted with 250 μ Al₂O_3, followed by oxidation and again sandblasted with 250 μ Al₂O₃. The dimensions of each specimen were adjusted so as to maintain the thickness of ceramic at 1 mm. The specimen were loaded on the assembly of the universal testing machine, and a cross head speed of 0.5 mm/min was used to apply a compressive force at the junction of metal and feldspathic porcelain. The force application continued until adhesive fracture occurred, and the readings of the load applied to that particular specimen were recorded.

Results:

The means for shear bond strength for Group I, II, III and IV were found to be (226.92 ± 1.67), (233.16 ± 3.85), (337.81 ± 16.97) and (237.08 ± 4.33), respectively. Means of shear bond strength among the groups were compared using one-way analysis of variance test. Comparison between individual groups were made with Tukey's Honestly Significant Difference post-hoc test.

Conclusion:

Different particle size and surface treatment have an important role on the bond strength of ceramic-metal interface. Greater particle size demonstrated higher bond strength.

Efficient decoy-state quantum key distribution with quantified security

We analyse the finite-size security of the efficient Bennett-Brassard 1984 protocol implemented with decoy states and apply the results to a gigahertz-clocked quantum key distribution system. Despite the enhanced security level, the obtained secure key rates are the highest reported so far at all fibre distances.

TCL1 shows a regulated expression pattern in chronic lymphocytic leukemia that correlates with molecular subtypes and proliferative state

Expression of the human oncogene TCL1 in transgenic mice produces B-cell tumors that resemble chronic lymphocytic leukemia (CLL) suggesting its role in B-cell tumorigenesis. To clarify the expression pattern and regulation of TCL1 in CLL, we assessed 213 primary tumors by immunohistochemistry (IHC), flow-cytometry and/or Western blot, using a new monoclonal antibody. TCL1 protein was detectable in the majority of CLL (90% by IHC) but showed marked variations across cases with virtual absence in approximately 10% of tumors. Higher TCL1 levels correlated with markers of the 'pre-germinal center' CLL subtype including unmutated VH status (P=0.005), ZAP70 expression (P=0.007), and presence of chromosome 11q22-23 deletions (P=0.04). Intratumoral heterogeneity in TCL1 levels was also prominent and explained in part by markedly lower TCL1 expression in proliferating tumor cells. In vitro exposure of CLL cells to interleukin-4 (but not other growth factors) produced progressive and irreversible decrease in TCL1 protein levels in association with the onset of proliferation. TCL1 expression patterns in CLL are complex and highly dynamic and appear to reflect both the histogenetic subtypes of the disease and the growth parameters of individual tumors. The observed regulation pattern suggests that TCL1 may exert its effects predominantly in the unmutated/ZAP70-positive tumor subset.

Increased sural nerve epineurial blood flow in human subjects with painful diabetic neuropathy

AIMS/HYPOTHESIS

The pathogenesis of painful diabetic neuropathy remains unknown. As a consequence we still do not have any effective, rational treatments and a greater understanding of the mechanisms is urgently required. Previous studies have shown no consistent morphological differences in the nerves of patients with and without painful neuropathy. The aim of this study was to compare epineurial haemodynamics in patients with chronic painful and painless neuropathy.

METHODS

The techniques of microlightguide spectrophotometry and fluorescein angiography were used to measure epineurial intravascular oxygen saturation and blood flow respectively. Eleven patients with painful and eight with painless neuropathy were studied, with the groups matched carefully in terms of severity of neuropathy and diabetes control.

RESULTS

Intravascular oxygen saturation was higher in the painful neuropathy group compared to those without pain (median 73.8% vs 67.7%, respectively; p=0.021). Fluorescein rise time was also faster in those with painful symptoms (median 18.3 s vs 53.6 s; p=0.046) indicating higher epineurial blood flow in these subjects.

CONCLUSION/INTERPRETATION

These results indicate that there are distinct differences in haemodynamics within the epineurium of the sural nerve in subjects with painful and painless neuropathy. Haemodynamic factors could therefore have an important role in the pathogenesis of neuropathic pain and might offer further insight into potential treatments for this distressing condition.

Prediction of prognosis in patients with uveal melanoma using fluorescence in situ hybridisation

BACKGROUND/AIMS

Uveal melanoma is the commonest malignancy of the eye, with a high proportion of patients dying of metastatic disease. Tumours showing a loss of chromosome 3 and gains of chromosome 8 are associated with a worse prognosis. The efficiency of fluorescence in situ hybridisation (FISH) in determining copy numbers of these chromosomes was assessed in individual tumours and related to patient survival.

METHODS

33 fresh frozen samples were analysed with centromeric probes for chromosomes 3 and 8. Patient outcomes were divided into two groups: (1) absence of genetic abnormalities (no genetic imbalance) and (2) presence of genetic abnormalities (genetic imbalance). The log rank test was used to compare survival, which was represented by Kaplan-Meier survival curves.

RESULTS

Of the 33 tumours analysed, 16 showed evidence of genetic imbalances. Of these 16 tumours, 14 patients had died by the end of the study, with 10 having died of liver metastases. Of the tumours without evidence of genetic imbalances, five patients had died by the end of the study, although none had died as a result of either liver metastases or from the primary uveal melanoma. The difference in survival between the two groups was highly significant (p<0.0001).

CONCLUSION

The authors have shown that FISH analysis for chromosome 3 and 8 is a reliable and efficient technique in the analysis of fresh frozen tumour specimens and is valuable in the prediction of prognosis in individuals with uveal melanomas.

Impact of moods and social context on eating behavior

The relationship of moods and social context to energy and nutrient intakes was examined to ascertain if these variables interact or function independently. The subjects were 78 predominantly white, obese women participating in weight-loss studies. Mean age was 36.7 (SD=7.6) and mean Body Mass Index was 32.1 (SD=3.6). Subjects completed 2-week baseline food diaries recording everything they ate, including moods and people present during the meals. Meals eaten in positive and negative moods were significantly larger than meals eaten in a neutral mood. Meals eaten with other people were significantly larger than meals eaten alone. There were no significant moods by social context interactions for total energy intake. Moods and social context functioned additively to increase the risk of over-eating. Macro nutrient analysis revealed only a main effect for social context. Percentage of calories from fat and protein were greater, whereas the percentage of carbohydrate was less in social context meals compared to meals eaten alone. Clinicians should conduct a functional analysis to assess exposure to the frequency and types of risky situations. Teaching people to cope more effectively with social situations and moods may increase the efficacy of weight loss and maintenance programs.

Preoperative localization of a parathyroid adenoma with Tc-99m sestamibi imaging in a patient with concomitant nontoxic multinodular goiter

Preoperative localization of parathyroid adenomas is useful in patients undergoing parathyroidectomy. The authors report a patient with hyperparathyroidism and an associated nontoxic nodular goiter. Technetium-99m sestamibi scintigraphy localized and differentiated the parathyroid adenoma from the multinodular goiter. Excellent correlation was found between preoperative radionuclide imaging and surgical pathology. Technetium-99m sestamibi parathyroid imaging may be a simple and helpful test in the surgical management of parathyroid adenomas, particularly in patients with nontoxic multinodular goiter.

The hot clot sign. A new finding in deep venous thrombosis on bone scintigraphy

Focal Tc-99m MDP uptake on bone scanning in regions of deep venous thrombosis (DVT) is reported in two patients with documented DVT. It is speculated that this uptake may be related to localized calcification or ossification, which is occasionally observed on radiographs of patients with chronic DVT.