Impact of acidic beverages on composition and surface characteristics of human teeth: scanning electron microscopic, stereomicroscopic and energy dispersive x-ray analyses.

OBJECTIVES: The objective of this study was to evaluate the effect of acidic beverages on the surface topography and elemental composition of human teeth. METHODS: A total of five highly acidic beverages (Red Bull, Pepsi, Apple Cidra, Tang Mosambi, and Tang Orange) were investigated. The tooth specimens of experimental groups were submerged in each beverage and incubated at 37 °C for 7 days, whereas, the tooth specimens of control groups were placed in distilled water. Afterwards, tooth specimens were analyzed using scanning electron microscopic (SEM), stereomicroscopic, and energy dispersive x-ray (EDX) techniques. RESULTS: All experimental groups revealed a decline in the tooth elements compared to controls, however, such decline was not statistically significant. Nevertheless, comparing the experimental groups, the Red Bull beverage caused a marked reduction in the percentage of both calcium and phosphorus elements compared to the Pepsi, Apple Cidra, Tang Mosambi, and Tang Orange beverages but it was insignificant as well in contrast to its control counterpart. All five acidic beverages demonstrated erosive potential under SEM analysis; however, each group of specimens showed a diverse amount of demineralization. In addition, all experimental groups exhibited significant discoloration of tooth specimens compared to their respective control counterparts. CONCLUSIONS: Within the limitations of study, all five acidic beverages demonstrated erosive potential in the simulated in vitro conditions under SEM analysis; however, each group of specimens exhibited a different extent of demineralization. In addition, the overall effect of all beverages was insignificant under EDX analysis as no substantial difference was revealed between the elemental composition of experimental and control group specimens.

Evaluating the pH of Various Commercially Available Beverages in Pakistan: Impact of Highly Acidic Beverages on the Surface Hardness and Weight Loss of Human Teeth.

The objectives of this study were to investigate the pH of common beverages and to evaluate the effects of common acidic beverages on the surface hardness and weight loss of human tooth specimens. A total of 106 beverages were conveniently purchased from supermarkets in Karachi, Pakistan. Prior to evaluation, beverages were refrigerated or stored at room temperature in accordance with the manufacturers' recommendations. Beverages were categorized into six groups: 'Sports and Energy drinks', 'Water', 'Fruit Juices and Drinks', 'Sodas', 'Milk and Flavored Milk' and 'Teas and Coffee'. Using a pH meter, the pH of each beverage was measured in triplicate at room temperature. In addition, the influence of five highly acidic beverages on the weight loss and surface hardness of human tooth specimens was evaluated using gravimetric analysis and the Vickers hardness tester, respectively. 'Sports and Energy drinks', 'Fruits Juices and Drinks' and 'Sodas' were the most acidic beverage categories, with a pH range of 3.00−5.00. A total of 33% of beverages tested in this study were highly acidic (pH less than 4.00), 29% of beverages were moderately acidic (pH 4.00−4.99) and 31% were mildly acidic (pH 5.00−6.99). Significant weight loss was observed in all immersed specimens compared to control counterparts (p < 0.05). Similarly, for surface hardness, five highly acidic beverages (Red Bull, Pepsi, Apple Cidra, Tang Mosambi and Tang Orange) significantly decreased the surface hardness of specimens (p < 0.05). The pH levels of commonly available beverages in Pakistan are highly acidic, which may encourage loss of minerals from teeth; hence, affecting their surface hardness.

Frequency and magnetic resonance imaging patterns of tuberculous spondylitis lesions in adults.

OBJECTIVE: To find out the frequency and patterns of various lesions in tuberculous spondylitis in adults on magnetic resonance imaging (MRI). STUDY DESIGN: Case series. PLACE AND DURATION OF STUDY: Radiology Department, Military Hospital (MH) Rawalpindi, from September 2006 to March 2007. METHODOLOGY: Patients with features suggestive of tuberculous spondylitis underwent plain T1- weighted and T2 -weighted images and T1-weighted contrast enhanced images in both axial and sagittal sections. The data was analyzed in terms of frequency and patterns of various lesions of tuberculous spondylitis causing abnormal signals in spinal and paraspinal areas. Mean + standard deviation were calculated for numerical data using SPSS version 15. RESULTS: Out of 75 patients, 39 were females. The mean age was 42.4 years. Involvement occurred through SV1 vertebral levels. Most common involvement was seen in the thoracic vertebrae (40%) followed by lumbar vertebrae. The most common MRI feature was abnormal signal intensities appearing hypointense on T1W and hyperintense on T2W sequences with heterogeneous enhancement of the vertebral body in all patients. The characteristic findings of spinal tuberculosis included destruction of two adjacent vertebral bodies and opposing end plates, destruction of intervening disc, and occurrence of paravertebral and epidural abscesses. CONCLUSION: MR imaging of spinal tuberculosis, characteristically show contiguous involvement of two vertebrae along with the intervening disc, skip lesions, and paraspinal collections and provides critical information about the involvement of spinal cord and the extent of the disease.

Determination of gestational age transverse cerebellar diameter in third trimester of pregnancy.

OBJECTIVE: To assess the usefulness of transverse cerebellar diameter (TCD) as an independent parameter for gestational age assessment in third trimester of pregnancy. DESIGN: An observational study. PLACE AND DURATION OF STUDY: Diagnostic Radiology Department, PNS Shifa, Karachi between April 2002 to July 2004. PATIENTS AND METHODS: This study was performed on patients between 26-38 weeks of gestation with normal pregnancy. Grey scale antenatal ultrasonography was done with 3.5 MHz probe to measure fetal transverse cerebellar diameter and was correlated with gestational age in weeks. These cases were followed progressively at different periods of gestation throughout the pregnancy. Collected data was converted into variables which were analyzed by SPSS version 10, descriptive statistics included mean +/- standard deviation which were computed for TCD and other fetal biometry parameters. RESULTS: Transverse cerebellar diameter varied in a linear fashion in third trimester, while transverse cerebellar diameter/abdominal circumference (TCD/AC) ratio remained constant in second half of pregnancy. All the parameters were expressed by regression equations and correlation coefficients were found to be statistically significant (r=0.99 for TCD, r=0.98 for TCD/AC all p<0.0001). CONCLUSION: This study signifies that transverse cerebellar diameter and TCD/AC ratio on serial sonography give an accurate idea of gestational age. Cases with intrauterine growth restriction can be diagnosed if local, nomogram can be prepared for different ethnic groups.