Evaluation of the marginal fit of full contoured zirconia, lithium disilicate and metal crowns fabricated using CAD-CAM: An in vitro study

Introduction

The marginal fit of any dental restoration is vital to its long-term success. Lack of adequate fit is potentially detrimental to both the tooth and the supporting periodontal tissues. The purpose of this study was to evaluate the marginal fit of monolithic zirconia, monolithic lithium disilicate and monolithic metal crowns and compare the three groups.

Methods

The study was conducted by fabricating ten samples for each group, total of 30 samples. A premolar stainless steel die was used to standardize the preparation. PVS putty material was used to make impressions of the model and was poured using type IV die stone. The samples were all fabricated using CAD-CAM. The marginal gap was measured by SEM, and the results were analysed using SPSS software.

Results

The mean marginal gap of zirconia, metal and lithium disilicate crowns was 79.49 μm, 46.83 μm and 70.79 μm, respectively.

Discussion

The metal group showed the lowest marginal gap among the groups. This difference in marginal fit is due to the sintering process where the organic binders in soft metal burn out and the metallic powder particles are being sintered (caked) without creating a fused phase.

Clinical Significance

Marginal fit plays a very important role in the long-term success of a crown. Discrepancy in marginal fit results in food and plaque accumulation causing caries and periodontal breakdown, eventuating the failure of the restoration. A perfect marginal fit would enhance the longevity of any indirect restoration. Knowledge about which indirect restoration has the best marginal fit is critical.

Microbiological status of some street iftar items collected from chalk bazar in Dhaka city, Bangladesh

In Dhaka, the capital of Bangladesh and one of the most densely populated cities of the world, different categories of street foods are widely consumed by all classes of people, especially for iftar during the holy month of Ramadan. The objective of this research was to assess the microbiological quality of street iftar food items collected from a street in Chalk Bazar locality of Dhaka along with the antibiogram profile of the bacterial isolates. A total of 74 samples belong to ten different categories of street food items and 8 different types of street vended juices were collected aseptically. The bacteria were isolated by using different culture media. The antibiotic susceptibility of the bacterial isolates was determined by the disc diffusion method. In case of street food total viable bacteria (on average of 6 log10 CFU/g). On the other hand, an extended number of total viable bacteria were encountered in all juices samples which also on an average of 6 log10 CFU/mL. Fungi, Pseudomonas spp. and Staphylococcus spp. were found in the majority of the samples irrespective of the categories. Few samples were contaminated with Escherichia coli and Klebsiella spp. Most of the cultivated bacterial strains exhibited resistance against commonly used antibiotics, while several isolates were noted to be multi-drug resistant. The present study revealed a huge array of microbial load which indicates a high risk to public health. Presence of antibiotic-resistant bacteria heightened the risk by many folds and urges the need for frequent surveillance.

Evaluation of microbial contamination level and the drug susceptible pattern of the isolates cultivated from famous dessert food

Present study endeavored to evaluate the microbial contamination level along with their drug resistant pattern in some popular desert food items collected from different food shops in Dhaka city, Bangladesh. The microbial evaluation was conducted through conventional cultural methods and drug susceptibility test was executed through disc diffusion method. All the samples were found to be contaminated with heterotrophic bacteria as well as fungi within the range of 103 to 105 CFU/g. In case of specific microflora, the growth of Staphylococcus spp. was very high in sweet, faluda, milk cake and ice cream as estimated up to 105 CFU/g, halua and sweet yogurt showed 104 CFU/g while rest of the samples revealed 103 CFU/g. E. coli was found only in faluda and ice cream up to 103 CFU/g whereas Klebsiella spp. was estimated in all the samples within the range of 102 CFU/g to 105 CFU/g. Salmonella spp., Pseudomonas spp. and Bacillus spp. were totally absent in all the samples. Most of the isolates were found to be resistant against most of the antibiotics. Meanwhile, streptomycin (10 µg), gentamicin (10 µg), azithromycin (15 µg), and nalidixic acid (5 µg) were effective drug against both E. coli and Staphylococcus spp.

Comparison of commercially available food decontaminants with established methods of decontamination for household practices which are used to keep foods safe

The microbiological safety of food has been a major concern in Bangladesh following several reports of food borne outbreaks associated with contaminated food and vegetables. To minimize the outbreak, several studies suggested that decontamination is necessary before cooking. Washing with water is the most common technique for decontamination in Bangladesh. In order to ensure food safety, the use of different food washing agents is also becoming popular day by day. For this reason, this study was conducted to evaluate the efficacy of various sanitizers and treatment method for decontamination. In this study, several decontamination methods including washing with hot water, cold water, salt water, vinegar and commercially available food sanitizer to evaluate for their efficacy against different microorganisms. Here, salad vegetables were washed with various sanitizers and then microbiological analysis was done to reveal the bacterial and fungal load. This study revealed that most of the sanitizing methods were able to reduce microbial load minimum by 2 log CFU/g. Vinegar and hot water wash were the most effective method of decontamination compare to others with the former showing a 3 log CFU/g reduction. This can be concluded that common items like the use of vinegar and hot water were more effective than the commercial decontaminating agents available.

BAYESIAN ANALYSIS OF COSMIC RAY PROPAGATION: EVIDENCE AGAINST HOMOGENEOUS DIFFUSION

We present the results of the most complete scan of the parameter space for cosmic ray (CR) injection and propagation. We perform a Bayesian search of the main GALPROP parameters, using the MultiNest nested sampling algorithm, augmented by the BAMBI neural network machine-learning package. This is the first study to separate out low-mass isotopes (p, p ¯ , and He) from the usual light elements (Be, B, C, N, and O). We find that the propagation parameters that best-fit p, p ¯ , and He data are significantly different from those that fit light elements, including the B/C and 10Be/9Be secondary-to-primary ratios normally used to calibrate propagation parameters. This suggests that each set of species is probing a very different interstellar medium, and that the standard approach of calibrating propagation parameters using B/C can lead to incorrect results. We present posterior distributions and best-fit parameters for propagation of both sets of nuclei, as well as for the injection abundances of elements from H to Si. The input GALDEF files with these new parameters will be included in an upcoming public GALPROP update.

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Implementation of a mass measles campaign in central Afghanistan, December 2001 to May 2002

In Afghanistan health services have been disrupted by 23 years of conflict and 1 of 4 children die before age 5 years. Measles accounts for an estimated 35,000 deaths annually. Surveillance data show a high proportion of measles cases (38%) among those >/=5 years old. In areas with complex emergencies, measles vaccination is recommended for those aged 6 months to 12-15 years. From December 2001 to May 2002, Afghan authorities and national and international organizations targeted 1,748,829 children aged 6 months to 12 years in five provinces in central Afghanistan for measles vaccinations. Two provinces reported coverage of >90% and two >80%. Coverage in Kabul city was 62%. A subsequent cluster survey in the city found 91% coverage (95% confidence interval [CI], 0.85-0.91) among children 6-59 months and 88% (95% CI, 0.87-0.95) among those 5-12 years old. Thus, this campaign achieved acceptable coverage despite considerable obstacles.

Evaluation of female external genitalia sensitivity to pressure/touch: a preliminary prospective study using Semmes-Weinstein monofilaments

OBJECTIVES

To assess the use of pressure aesthesiometers (Semmes-Weinstein monofilaments) in the evaluation of female external genitalia. The pressure aesthesiometers are widely used to assess the pressure/touch perceptions of the hand, face, and breast dermatomes.

METHODS

Thirty-two consecutive neurologically intact women (mean age 48.7 +/- 13.8 years) and 5 neurologically impaired women referred for a routine gynecologic examination were prospectively enrolled. The monofilaments were applied to the S2-S5 vulvar dermatomes using specific anatomic landmarks. Test-retest reliability studies were performed at the same clinical session. A comparison was made between premenopausal (n = 17) and postmenopausal (n = 15) women; hypoestrogenic (n = 9) and normoestrogenic (n = 23) women; postmenopausal women with (n = 6) and without (n = 9) estrogen replacement therapy; women with normal (n = 18) and abnormal (n = 14) sexual function; and neurologically impaired (n = 5) and neurologically intact (n = 5) women, matched by age, parity, and estrogen status.

RESULTS

A clear association was found between reduced vulvar sensitivity to pressure/touch and estrogen deficiency, sexual dysfunction, and neurologic impairment. Postmenopausal women had significantly reduced sensitivity to pressure/touch compared with premenopausal women. Similar decreased sensitivity was found in hypoestrogenic compared with normoestrogenic women, with significantly reduced sensitivity in postmenopausal women not using estrogen replacement therapy. Women with sexual dysfunction and those with neurologic impairment had significantly reduced vulvar sensitivity to pressure/touch. No correlation was found between the sensitivity to pressure/touch and either levator ani muscle bulk or the levator contraction score, but significant differences were found between women with and without vulvovaginal atrophy at the time of the examination. Test-retest analysis confirmed the reliability of the monofilaments in testing vulvar sensation.

CONCLUSIONS

The Semmes-Weinstein monofilaments may be used as a valid and reliable diagnostic tool in the evaluation of vulvar sensitivity to pressure/touch. Additional studies with larger series are needed to establish the role of this clinical tool in the evaluation of various treatment outcomes.

Pretreatment of endometrial carcinoma cell lines with butyrate results in upregulation of Bax and correlates with potentiation of radiation induced cell kill

BACKGROUND

Endometrial carcinoma is the most common gynecologic malignancy. Surgery has been the standard therapy for stage I and II endometrial carcinoma and radiation therapy either before or after surgery has been used to improve local control especially for high grade lesions. We have used Sodium Butyrate (BA) in order to examine whether endometrial carcinoma cells can be rendered more sensitive to radiation therapy.

METHODS

Endometrial carcinoma cells in culture were pretreated with sodium butyrate and then irradiated. Clonogenic survival assay was used to determine percentage of surviving cells. Changes in Bax and Bcl-2 protein levels were determined by Western blot analyses. Effect of Bcl-2 overexpression on induction of Bax in response to butyrate pretreatment was studied in cells transfected with Bcl-2.

RESULTS

A 24 h pretreatment of SKUT2 and Hec-1A cells with BA has an additive effect with radiation. Analysis of pro and anti-apoptotic protein levels revealed that the 24 h pretreatment with BA resulted in increased expression of the proapoptotic protein Bax which correlated with potentiation of radiation induced cell kill. Treatment of cells over expressing Bcl-2 with BA did not show induction of Bax suggesting that higher levels of Bcl-2 can block butyrate induced increase in levels of Bax.

CONCLUSIONS

Use of BA at lower than toxic doses to upregulate the proapoptotic potential of cancer cells may be useful in an adjuvant or neoadjuvant setting but its success may depend upon the intrinsic Bcl-2 levels in the tumor.

Metastatic breast carcinoma to the abdomen and pelvis

OBJECTIVE

The role of surgical resection of metastatic breast cancer to the abdomen and pelvis is controversial. The objective of this study is to describe the characteristics, surgical management, and outcome of women with a history of breast adenocarcinoma who developed abdominal or pelvic metastases during follow-up.

METHODS

We retrospectively reviewed the medical records of 40 female patients with documented invasive breast cancer who were referred to the Gynecology Service between 1986 and 1995 and were found to have metachronous abdominal and/or pelvic metastases.

RESULTS

The median patient age at exploration by the Gynecology Service was 53.5 years (range 27-79 years), and the median interval from breast cancer diagnosis to exploration was 80 months (range 9-264 months). The majority of patients, 32 (80%), had a preoperative diagnosis of a new pelvic mass or suspected abdominal carcinomatosis. With a median follow-up of 14.2 months following the diagnosis of abdominal or pelvic metastasis, the median survival for all patients was 24.1 months. Patients who had no gross residual disease in the abdomen or pelvis after surgery had a median survival of 41.6 months, which did not significantly differ from those with gross residual < or =2 cm (16.1 months) or >2 cm (18.4 months) (P = 0.624).

CONCLUSION

Metachronous abdominal and pelvic metastases from breast cancer may appear many years following initial diagnosis and are often operated on by gynecologists because of their clinical presentation. Surgical resection may be indicated in some symptomatic patients; however, the survival advantage of surgical cytoreduction remains to be determined.