Effect of Hypochlorites on the Compressive Strength and Surface Hardness of Type V Dental Stone: An In Vitro Study.

AIM: The study aimed to evaluate the compressive strength and surface hardness of a type V dental stone after hypochlorite disinfection. MATERIALS AND METHODS: Two types of specimens were made according to the American Dental Association (ADA) specification no. 25 for each wet compressive strength, dry compressive strength, and surface hardness. The specimens were split into three groups with 30 samples each according to the type of disinfection. All specimens were immersed in their respective disinfecting solutions for 30 minutes at room temperature and after removal, they were left to dry for 24 hours at room temperature. Total five cycles of immersion and drying were followed. A compressive strength test was done using a universal testing machine. Wet compressive strength was tested one hour after the last cycle and dry compressive strength was tested 7 days after the last cycle. Surface hardness was measured after 48 hours using Vickers hardness test. The results were statistically analyzed. RESULTS: There was a statistical difference between the calcium hypochlorite and sodium hypochlorite groups for both dry and wet compressive strength. The mean wet compressive strength of calcium hypochlorite was higher when compared to the sodium hypochlorite group and it was statistically significant (p = 0.042). The results were similar and statistically significant (p = 0.003) for dry compressive strength. When the mean surface hardness of the sodium hypochlorite (As) group was compared to calcium hypochlorite the results were highly significant (p = 0.0001) with the mean surface hardness of the calcium hypochlorite group more than the sodium hypochlorite group. CONCLUSION: Calcium hypochlorite used as a disinfectant showed better compressive strength and surface hardness when compared to sodium hypochlorite as a disinfectant. CLINICAL SIGNIFICANCE: Dental casts poured in the contaminated impressions which might not be disinfected at all or properly. They also come in contact with the prosthesis that might be tried inside the patient's mouth and sent to a lab for corrections without disinfecting the cast causing cross-contamination between patients, dentists, and laboratory personnel. However, immersion disinfection with sodium or calcium hypochlorite might affect important properties of the cast. Any negative effect on the mechanical or physical properties of the cast will affect the final outcome of the prosthesis.

Delaying clozapine: how long is too long?

BACKGROUND: Although clozapine is the most effective drug for treatment-resistant schizophrenia, its use remains restricted in clinical practice in India. The delay in initiating treatment with clozapine and its impact on disease outcome needs evaluation. AIM: To identify the implications of delaying clozapine initiation in clinical outcomes among people with treatment-resistant schizophrenia. METHODS: Subjects with treatment-resistant schizophrenia, stabilised on clozapine monotherapy, were recruited from the outpatient clinic of a general hospital psychiatry unit offering tertiary care services in Thrissur district, Kerala, India. A retrospective cohort design was employed, and information on duration of illness, total duration of treatment and duration of treatment with clozapine was collected. Present symptom status was measured using the Positive and Negative Syndrome Scale. Factors associated with higher symptom scores were analysed using an independent sample t test, Spearman correlation and multiple linear regression. RESULTS: Forty subjects stabilised on long-term clozapine therapy formed the study sample. The mean dose of clozapine used in the study population was 200 mg. The mean duration of antipsychotic treatment before starting clozapine was 89.3 months (7.4 years). The duration of treatment before starting clozapine was found to have a significant positive association with the total Positive and Negative Syndrome Scale score (correlation coefficient 0.40; p=0.01) and negative symptom score (correlation coefficient 0.33; p=0.04). The multiple regression analysis adjusting for covariates showed that the duration of treatment before starting clozapine was an independent factor associated with a higher negative symptom score in the Positive and Negative Syndrome Scale (slope ß=0.05; p=0.02; R2=0.27). CONCLUSION: Poor treatment outcomes in treatment-resistant schizophrenia could be secondary to a delay in initiating clozapine therapy.

Flexural Strength of Surface-Treated Heat-Polymerized Acrylic Resin after Repair with Aluminum Oxide-Reinforced Autopolymerizing Acrylic Resin.

BACKGROUND: A fracture of denture base in situ often occurs through a fatigue mechanism, which over a period of time leads to the formation of small cracks, resulting in fracture. AIM AND OBJECTIVE: To evaluate the flexural strength of repaired heat-polymerized acrylic resin, with different percentage of aluminum oxide (Al2O3) added to the repair resin and effect of two different surface treatments on the flexural strength of repaired heat-polymerized acrylic resin and also to evaluate quantification of filler particles using scanning electron microscopy. MATERIALS AND METHODOLOGY: Fifty specimens of heat-polymerized acrylic resin were prepared according to the American Dental Association specification no. 12 (65 mm × 10 mm × 2.5 mm). Al2O3<50 nm particle size was silanized using metal alloy primer before incorporation in polymer. Two different percentages of Al2O3 nanoparticles, that is, 1% and 1.5% were added to autopolymerizing acrylic resin which was used as repairing material. RESULTS: The study showed that repair resin incorporated with 1.5% Al2O3 in the group surface treated with silicon carbide paper improved the flexural strength of denture base resin. A proper filler distribution and deep penetration within the polymer matrix were observed by scanning electron microscope in the same group.

A case of adrenoleukodystrophy presenting with manic symptoms in a patient on steroids for Addison's disease.

Adrenoleukodystrophy (ALD) is an X-linked disorder with diverse clinical presentations. A 30-year-old male, previously diagnosed with Addison's disease, on steroid supplementation for 18 years, presented to us with manic symptoms for 4 years. He was found to have white matter hypodensities in computed tomography head and had white matter signal changes in magnetic resonance imaging, and therefore a diagnosis of ALD was made.

In-vitro activity of saponins of bauhinia purpurea, madhuca longifolia, celastrus paniculatus and semecarpus anacardium on selected oral pathogens.

OBJECTIVE: Dental caries, periodontitis and other mucosal diseases are caused by a complex community of microorganisms. This study aimed to investigate the antimicrobial properties of saponins of four important oil yielding medicinal plant extracts on selected oral pathogens that are involved in such diseases. MATERIALS AND METHODS: Saponins were extracted from Bauhinia purpurea, Madhuca longifolia, Celastrus paniculatus and Semecarpus anacardium and purified. Antimicrobial properties of these saponins against Streptococcus mutans, Streptococcus mitis, Streptococcus salivarius, Staphylococcus aureus and Lactobacillus acidophilus were determined using well diffusion method. The minimum inhibitory concentration (MIC) was determined as the lowest concentration of saponins inhibiting bacterial growth after 14 h of incubation at 37°C. The bactericidal activity was evaluated using the viable cell count method. RESULTS: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Madhuca longifolia saponin on Streptococcus mutans MTCC 890, Streptococcus mitis and Staphylococcus aureus was 18.3 ± 0.15/34.4 ± 0.24 µg/ml, 19.0 ± 0.05/32.2 ± 0.0 µg/ml and 21.2 ± 0.35/39.0 ± 0.30 µg/ml, respectively and Bauhinia purpurea saponin on Streptococcus mutans MTCC 890, Staphylococcus aureus and Lactobacillus acidophilus was 26.4 ± 0.20/43.0 ± 0.40 µg/ml, 29.0 ± 0.30/39.6 ± 0.12 µg/ml and 20.2 ± 0.05/36.8 ± 0.23 µg/ml, respectively. CONCLUSION: The strong antimicrobial activity of Madhuca longifolia and Bauhinia purpurea may be due to the presence of complex triterpenoid saponins, oleanane type triterpenoid glycosides or atypical pentacyclic triterpenoid saponin. Hence, these extracted saponins may be used in food and oral products to prevent and control oral diseases.

Indian research on aging and dementia.

All the articles published in the Indian Journal of Psychiatry (IJP) from 1958 to 2009 on aging, dementia and other mental health issues of late life were systematically reviewed. There were only a limited number of research articles on dementia in the IJP. Most of the Indian studies on dementia were published elsewhere. People above the age of 60 years constitute about 5% of patients seen in tertiary care settings. High prevalence of psychiatric morbidity was reported among community resident older people. Depression was the commonest mental health problem in late life. We need to develop community-based interventions for management of common conditions like depression in late life. The effectiveness of these interventions needs to be established. It is important to identify risk factors for depression and dementia in our population. We could then try and modify these factors to reduce the prevalence of these conditions.