Reinforcement of Teeth Having Reenacted Perforating Internal Resorption Cavities After Repair Using Different Calcium Silicate-based Cements and Backfilling Materials: An In vitro Study.

To evaluate the fracture resistance (FR) of the teeth having reenacted perforating internal resorption cavities repaired by distinctive calcium silicate-based cements (CSCs) specifically: Endocem MTA, Biodentine, NeoMTA Plus, and backfilling materials. Ninety-six freshly extracted human mandibular premolar teeth were selected. Twelve roots were used as the negative control group. Rotary files were used to complete the final irrigation and root canal preparation on the remaining teeth. Following that, burs were used to make standardized internal resorption chambers in the middle part of the roots. Twelve of these samples were used as positive control samples. The remaining 72 root canals were obturated in the apical 4 mm using a single-cone approach, and they were separated into 6 groups based on the CSCs used to fill voids and the materials used as backfilling. Group 1: Endocem MTA (resorption) + Endocem MTA (coronal), Group 2: Endocem MTA (resorption) + Gutta-percha/sealer (coronal), Group 3: Biodentine (resorption) + Biodentine (coronal), Group 4: Biodentine (resorption) + Gutta-percha/sealer (coronal), Group 5: NeoMTA Plus (resorption) + NeoMTA Plus (coronal), and Group 6: NeoMTA Plus (resorption) + Gutta-percha/sealer (coronal). Specimens were inserted in acrylic resin and then subjected to fracture testing. Fracture strength tests were performed using a Universal Testing Machine. The force was employed vertically with a consistent speed of 1 mm/minute. The results were analyzed with Variance and Bonferrini tests at P < 0.005. The mean force of fracture values were 447.00, 201.25, 318.75, 187.50, 596.58, 258.75, 347.50, and 298.75 N for Group 1, 2, 3, 4, 5, 6, 7, and 8, respectively. "There was a significant difference (P < 0.001) between the experimental groups and the control group". Group 5 showed the highest FR as compared to other groups. Backfilling with CSCs appears to be a better material than a gutta-percha/sealer combination. Neo MTA plus furthermore appeared the highest fracture-resistant material, while Biodentine + Gutta percha/sealer showed the least FR.

Comparison of rate of canine retraction into recent extraction site with and without gingival fiberotomy: a clinical study.

AIM: Retraction of maxillary canines after first premolar extractions is a very common orthodontic task in cases of crowding or for the correction of large overjet. Many studies have been done to increase the rate of retraction. The aim is to compare the rate of canine retraction into recent extraction site with and without circumferential supracrestal fiberotomy. MATERIALS AND METHODS: The rate of movement of the canines into the recent extraction site of the first premolar with or without circumferential supracrestal fiberotomy was measured in 14 patients aged 13 to 22 years. The study was done on 9 maxillary and 5 mandibular arches. The appliance used in the present study was the preadjusted edgewise (0.022 inch Roth prescription) and retraction performed by frictionless mechanics using Composite T Loop. The distalization of canines was measured at regular intervals (T1, T2, T3 and T4). Recordings of the positions of the canines at the beginning and at different intervals were made from dental casts. RESULTS: The mean difference between the two sides for the total time span T1-T4, for maxillary arch was 0.36 mm and for mandibular arch was 0.60 mm respectively. CONCLUSION: There can be various factors that affect the rate of tooth movement. Factors like bone density, bone metabolism, and turnover in the periodontal ligament, amount of force applied may be responsible for the variation. CLINICAL SIGNIFICANCE: No clinically significant increased rate of retraction of cuspids in the recent extraction site with fiberotomy was found in comparison to the retraction in recent extraction site without fiberotomy.

Accurate distortion estimation and optimal bandwidth allocation for scalable H.264 video transmission over MIMO systems.

In this paper, we propose an optimal strategy for the transmission of scalable video over packet-based multiple-input multiple-output (MIMO) systems. The scalable extension of H.264/AVC that provides a combined temporal, quality and spatial scalability is used. For given channel conditions, we develop a method for the estimation of the distortion of the received video and propose different error concealment schemes. We show the accuracy of our distortion estimation algorithm in comparison with simulated wireless video transmission with packet errors. In the proposed MIMO system, we employ orthogonal space-time block codes (O-STBC) that guarantee independent transmission of different symbols within the block code. In the proposed constrained bandwidth allocation framework, we use the estimated end-to-end decoder distortion to optimally select the application layer parameters, i.e., quantization parameter (QP) and group of pictures (GOP) size, and physical layer parameters, i.e., rate-compatible turbo (RCPT) code rate and symbol constellation. Results show the substantial performance gain by using different symbol constellations across the scalable layers as compared to a fixed constellation.

Comparison of low-dose pegylated interferon versus standard high-dose pegylated interferon in combination with ribavirin in patients with chronic hepatitis C with genotype 3: an Indian experience.

BACKGROUND AND AIMS: In chronic hepatitis C virus (HCV) infection with genotype 3, therapy with pegylated interferon (peg-IFN) alfa-2b in a dose of 1.5 mug/kg/week and ribavirin (800-1000 mg/day) is recommended for 24 weeks. Reduced doses of peg-IFN may increase compliance and decrease cost and adverse events. This study aimed to assess the safety and efficacy of two different regimens of peg-IFN alfa-2b, in combination with ribavirin, in genotype 3 patients. METHODS: A total of 103 liver biopsy-proven chronic HCV patients with genotype 3, having alanine aminotransferase levels >1.2 x ULN and positive HCV-RNA were randomized into two groups: group I (n = 76; age, 43.1 +/- 11.4 years; male/female, 67/9) received peg-IFN 1.0 mug/kg/week + ribavirin 10.6 mg/kg/day, while group II (n = 27; age, 37.3 +/- 11.6 years; male/female, 21/6) received peg-IFN 1.5 microg/kg/week + ribavirin 10.6 mg/kg/day. Patients in both groups were treated for 24 weeks. End of treatment viral response (ETVR) and sustained viral response (SVR) after a 6-month follow-up period were assessed. RESULTS: In both groups I and II, one patient was lost to follow-up, while one patient in group II withdrew due to side-effects. ETVR was seen in 72/76 (94.7%) of patients in the low dose group and 24/27 (88.9%) of patients in the high dose group (P = 0.375). SVR was seen in 60/76 (78.9%) of patients in the low dose group and 25/27 (92.6%) of patients in the high dose group (P = 0.145). Age (Pearson correlation coefficient = 0.263; P = 0.008) and fibrosis (correlation coefficient, 0.263; P = 0.008) showed a significant correlation with the SVR. CONCLUSION: In patients with genotype 3, peg-IFN at 1.0 microg/kg/week with ribavirin is as effective as peg-IFN at 1.5 mug/kg/week with ribavirin.

Coexistence of chronic calcific pancreatitis and celiac disease.

Coexistence of celiac disease with chronic calcific pancreatitis is rare. We describe a 26-year-old woman with chronic calcific pancreatitis in whom non-response to treatment was due to celiac disease.

A wavelet-based multiresolution approach to solve the stereo correspondence problem using mutual information.

In this correspondence, we propose a wavelet-based hierarchical approach using mutual information (MI) to solve the correspondence problem in stereo vision. The correspondence problem involves identifying corresponding pixels between images of a given stereo pair. This results in a disparity map, which is required to extract depth information of the relevant scene. Until recently, mostly correlation-based methods have been used to solve the correspondence problem. However, the performance of correlation-based methods degrades significantly when there is a change in illumination between the two images of the stereo pair. Recent studies indicate MI to be a more robust stereo matching metric for images affected by such radiometric distortions. In this short correspondence paper, we compare the performances of MI and correlation-based metrics for different types of illumination changes between stereo images. MI, as a statistical metric, is computationally more expensive. We propose a wavelet-based hierarchical technique to counter the increase in computational cost and show its effectiveness in stereo matching.

Pegylated interferon alfa 2b and oral ribavirin in patients with HCV-related cirrhosis.

BACKGROUND: The treatment of hepatitis C virus (HCV)-related cirrhosis is difficult due to high frequency of adverse effects. We retrospectively reviewed the case records of patients with HCV cirrhosis to evaluate the efficacy and tolerability of pegylated (peg) interferon and ribavirin treatment in these patients. METHODS: Medical records of 28 patients with HCV-related compensated cirrhosis were reviewed. The treatment protocol was a combination therapy of peg interferon alfa-2b (1 microg/Kg/week) plus oral ribavirin (10-12 mg/Kg/day). Primary endpoint was sustained virological response, with additional endpoints of drug tolerance, clinical or biochemical worsening and death. RESULTS: End-of-treatment virlogic response was seen in 24 of 28 patients (85%) and sustained virologic response in 15 of 28 (53%) patients. Biochemical end-of-treatment response and sustained response were seen in 20 and 16 patients (71% and 57%), respectively. Treatment had to be stopped in 3 patients due to decompensation of liver status in two and drug intolerance in one, while dose modification was required in two patients. CONCLUSIONS: Combination therapy with peg interferon plus ribavirin seems effective in patients with liver cirrhosis. High relapse rate, poor biochemical recovery and possibility of decompensation are issues that need to be kept in mind.

Infliximab in patients with severe steroid-refractory ulcerative colitis: Indian experience.

INTRODUCTION: The role of infliximab in the treatment of acute severe ulcerative colitis is established. However, all the data available in the literature are from western countries. This is the first report on the use of infliximab in patients with severe steroid-refractory ulcerative colitis from India. METHODS: Retrospective analysis of 28 patients who had received infliximab therapy for induction of remission, with three doses of 5 mg/kg at 0, 2, and 6 weeks, was performed. RESULTS: Twenty-four (85.6 %) patients had shown a clinical response by week 8 and, hence, avoided urgent colectomy. In 2 years of follow up, 9/16 (56 %) patients had not required colectomy. CONCLUSION: Infliximab averted colectomy in a proportion of patients with severe steroid-refractory ulcerative colitis.

Low hygiene and exposure to infections may be associated with increased risk for ulcerative colitis in a North Indian population.

BACKGROUND: Previous studies have attempted to link hygiene hypothesis with IBD. However most of these studies come from developed countries where the level of hygiene is high and universal. Very little data is available from developing countries. The present study explores the truth of hygiene hypotheses and other risk factors for ulcerative colitis (UC) in a North Indian population where the prevalence of UC has been increasing. METHODS: A total of 518 patients diagnosed with UC and 188 age-matched controls were included in the study. A structured questionnaire concerning socio-demographics and level of hygiene was completed by all participants. Logistic regression analysis was used to study the association between hygiene-related factors and the risk for UC. Odds ratios and 95% confidence intervals were estimated. RESULTS: There was a higher proportion of females (P<0.001), and a higher educational status (P=0.01) in UC patients compared with controls. A family history of IBD was present in 7.2% of cases and non-existent in controls. On multivariate analysis, after accounting for potential confounders, having a private bed (P<0.001), and having better toilet facilities [(RCA versus none, P=0.01; Flush toilet versus none, P=0.01), (RCA LATRINE as a toilet technology used in rural areas where no flush facility exists. It was developed under RCA project)] were inversely associated with risk for UC whereas owning a pet (P=0.01) and stressful events like a death in the family (P=0.01) were associated with greater risks for UC. CONCLUSION: Our study does not provide definitive evidence to support hygiene hypothesis and rather suggests that the rising incidence of UC in North India may be attributable to inadequate sanitary measures or other as yet unidentified factors.

Perinatal transmission of hepatitis C virus in northern India.

Data on transmission of HCV infection from mother to infant in India are limited. Between July 2006 to June 2007, women attending our hospital in the third trimester of pregnancy were screened for anti-HCV. Those testing positive for anti-HCV were tested for HCV RNA. Infants of mothers with HCV infection were followed for up to 24 months. Eight of 488 pregnant women (1.6%) tested positive for anti-HCV; of these, seven had detectable HCV RNA. Two of 7 (29%) children born to HCV-infected mothers had persistently positive HCV RNA, indicating perinatal transmission; one additional child had transient HCV positivity. Passive transfer of HCV antibodies was observed in five babies. HCV infection was detected in 1.4% of pregnant women, and perinatal transmission of HCV to newborns was detected in 29% of such cases.

Prevalence of hepatitis C virus in a selected geographical area of northern India: a population based survey.

BACKGROUND AND AIM: Epidemiological data on hepatitis C virus (HCV) infection from India are scanty. We conducted a population-based seroepidemiologic survey to estimate the prevalence of hepatitis C in Punjab state of northern India. METHODS: A house-to-house survey was conducted in a defined population of 26,273 subjects. Information was gathered according to a predesigned questionnaire with socio-demographic characteristics (age, gender and substance abuse), family history of HCV infection, general health status, associated co-infection, immunization history and potential risk factors for HCV transmission. At the time of clinical evaluation, blood was tested for anti-HCV and those found positive were tested for HCV RNA. RESULTS: Among 5,258 subjects screened, 272 were found to be anti-HCV positive (prevalence rate of 5.2 %); highest prevalence being noticed in 41-60 years age group. Anti-HCV positive rate were not different among males and females. Sixty-seven subjects (1.3 %) were found to be HBsAg positive; four of these being co-infected (5.9 %). Various risk factors for acquiring HCV infection identified were history of surgery, dental treatment and unprotected sex. Other associations were strong family history of HCV positivity, alcohol consumption and diabetes mellitus. CONCLUSION: Chronic HCV infection is a major health problem in Punjab; it appears to be more common than HBV infection. Exercising safe health care related procedures should be emphasized in our country as main modes of transmission of infection identified were related to these.

Long term results of use of azathioprine in patients with ulcerative colitis in India.

AIM: To evaluate the role of azathioprine (AZA) in Indian patients with ulcerative colitis over longer duration of time. METHODS: One hundred fifty six patients with ulcerative colitis who were treated with AZA from January 1995 to December 2003 were reviewed. The indications for its use were as follows: (1) steroid dependent and steroid refractory disease; (2) Azathioprine monotherapy for naive patients with severe disease; and (3) combination therapy (AZA + sulfasalazine or 5-aminosalicylates) for naive patients with severe disease. The data included patient and disease demographics, efficacy and toxicity profile of AZA. Patients with a minimum duration of 6 mo use of AZA were included in this report. RESULTS: Of a total of 156 patients treated with AZA, 45 were excluded from analysis for the following reasons- (follow up less than 6 mo, n = 9; poor follow up, n = 18; adverse affects, n = 18). In steroid refractory/dependent group the mean number of relapses prior to and post initiation of AZA therapy were 3.28 (+/- 0.81) and 0.94 (+/- 0.29) respectively. Discontinuation of steroids could be accomplished in 12 of the 15 steroid dependent patients. The proportion of patients with sustained remission of 1, 2, 3, 4 and 5 years duration were calculated. Eighteen patients experienced adverse effects necessitating withdrawal of AZA (pancreatitis, n = 7; hepatitis, n = 3; gastrointestinal intolerance, n = 2; alopecia, n = 2; and hematological, n = 4) while 13 patients needed dose reduction or temporary withdrawal of the drug. CONCLUSION: Azathioprine is well tolerated and has therapeutic benefits lasting as long as 4 years. Adverse effects such as pancreatitis, hepatitis, cytopenias and gastrointestinal symptoms do occur but are controlled by drug withdrawal only.

A preliminary assessment of cephalometric orthodontic superimposition.

The superimposition of cephalograms is a valuable tool in orthodontics. In children this task is complicated by the fact that growth changes in the reference structures used in superimposition should be taken into consideration. In this study a new method of superimposition of cephalograms taken in the natural head position (NHP) was compared with Viazis' cranial base triangle and a reference grid was used to quantitatively assess the changes in the five selected landmarks. The material consisted of 12 pairs of cephalograms of growing subjects (mean age 11.1 years) collected with a time interval of 1 year. The results revealed no significant statistical difference between the two methods and both showed high reproducibility. Both analyses were found to be suitable for individual assessment, but the new method involving the use of NHP and easy landmark identification can be considered as a useful addition.