Effect of screw hole filling on retention of implant crowns

The screw access channels of 15 degrees angled Esthetic Abutments (Br?nemark System) were either (a) completely filled with a vinyl polysiloxane impression material (Memosil), (b) partially filled with Memosil or (c) had lower portion filled with Memosil and the remainder with composite resin. The force required to remove a temporarily cemented restoration was measured. The removal force was significantly reduced with the channel completely filled with Memosil compared to those partially filled with Memosil (p<0.01) or with composite resin placed over Memosil (p<0.01). The method selected to fill the screw access channel of an implant abutment can be a significant factor affecting retention of a cemented restoration.     

Brightness (value) sequence for the Vita Lumin Classic shade guide reassessed

The purpose of this study was to locate the 16 shade tabs from the Vita Lumin 'Classic' shade guide within the quantitative Luminosity, R, G and B scales (0-255 scales) using Photoshop software. A new value order arranged according to the Photoshop scale demonstrated a more linear relationship between the 16 shade tabs than the order given by the manufacturer. A Brightness Index representing the percentage difference in value between pairs of reordered shade tabs is suggested as a more realistic determinant of change in shade tab value.     

Prevalence of and factors affecting post-obturation pain in patients undergoing root canal treatment

AIM: This longitudinal, prospective study (1) investigated the prevalence of post-obturation pain after root canal treatment and (2) evaluated the influence of factors affecting the pain experience. METHODOLOGY: Twenty practitioners, comprising general dental practitioners, MSc graduates and Endodontists, participated in this study. The patient sample (n = 415) was derived from consecutive patients attending the practitioners' surgeries for root canal treatment on a single tooth. Demographic, medical history, preoperative and intra-operative data as well as pain experience on day 1 and day 2 after root canal obturation were recorded. Intensity of pain experienced was recorded on a visual analogue scale (VAS) of 0-5. The data were analysed using logistic regression models. RESULTS: The prevalence of post-obturation pain within 48 h after treatment was 40.2% (n = 167) but less than 12% of patients experienced severe pain (VAS 4 or 5) on either day 1 or day 2. The factors that significantly influenced post-obturation pain experience were: gender (OR = 0.434, P < 0.001), tooth type (OR = 1.733, P = 0.007), size of periapical lesion (OR = 0.493, P = 0.004), history of post-preparation pain (OR = 4.110, P = <0.001) or generalized swelling (OR = 3.435, P = 0.005) and number of treatment visits (OR = 2.604, P < 0.001). CONCLUSIONS: The prevalence of post-obturation pain was high (40.2%). The important prognostic determinants of post-obturation pain were female, molar tooth, size of periapical lesion smaller than 3 mm, history of post-preparation pain or generalized swelling and single-visit treatment.     

肝动脉栓塞微球的研究

本文用乳化聚合法制备了明胶和聚乙烯醇两种微球,通过正交试验,确定了制备特定粒径微球的最佳工艺条件。以氟脲嘧啶和甲氨喋呤为模型药物,对明胶微球的体外溶出特性进行了探讨,结果表明,经复合交联能延缓药物的体外溶出。实验狗灌注微球前后的肝动脉造影表明术后肝动脉分枝有不同程度的减少;病理检查表明微球沉积于肝血窦前的肌性小动脉;γ-射线扫描也证实锝标记微球在肝内的特异性分布。     

肝动脉栓塞微球的研究

本文用乳化聚合法制备了明胶和聚乙烯醇两种微球,通过正交试验,确定了制备特定粒径微球的最佳工艺条件。以氟脲嘧啶和甲氨喋呤为模型药物,对明胶微球的体外溶出特性进行了探讨,结果表明,经复合交联能延缓药物的体外溶出。实验狗灌注微球前后的肝动脉造影表明术后肝动脉分枝有不同程度的减少;病理检查表明微球沉积于肝血窦前的肌性小动脉;γ-射线扫描也证实锝标记微球在肝内的特异性分布。     

A laboratory investigation of the accuracy of the repositioning impression coping technique at the implant level for single-tooth implants

This study investigated the accuracy of the repositioning impression technique at the implant level using vinyl polysiloxane impression material. Three groups each of ten senior dentists, postgraduate students and technicians were asked to use this technique to record the position of an implant in a master model. The Reflex Microscope was used to measure variations between the resulting casts and the master model. Significant difference between the casts and the master model in the X and Y-axes (p < 0.01) was recorded. Alarming inclinational and rotational errors for the implant analogue position were measured with all groups of operators. Similar distortion in the Z-axis was recorded.     

Factors affecting the bioavailability of soy isoflavones in humans after ingestion of physiologically relevant levels from different soy foods

The precise role that isoflavones play in the health-related effects of soy foods, and their potential for adverse effects are controversial. This may be due in part to a lack of basic knowledge regarding their bioavailability and metabolism, particularly as it relates to the soy source. To date, there is little information concerning possible differences in the bioavailability of isoflavones derived from natural soy foods consumed at physiologically relevant intakes and whether age- or gender-related differences influence that bioavailability. In the current study of healthy adults [premenopausal (n = 21) and postmenopausal (n = 17) women and a group of men (n = 21)], we examined the effect of age, gender, and the food matrix on the bioavailability of isoflavones for both the aglycon and glucoside forms that are naturally present in 3 different soy foods, soy milk, textured vegetable protein, and tempeh. The study was designed as a random crossover trial so that all individuals received each of the 3 foods. The dose of isoflavones administered to each individual as a single bolus dose was 0.44 mg/kg body weight. Pharmacokinetic parameters were normalized to mg of each isoflavone ingested per kilogram body weight to account for differences in daidzein and genistein content between the diets. Serum isoflavone concentrations in all individuals and groups increased rapidly after the ingestion of each soy food; as expected, genistein concentrations exceeded daidzein concentrations in serum. In this small study, gender differences in peak concentrations of daidzein were observed, with higher levels attained in women. Consumption of tempeh (mainly isoflavone aglycon) resulted in higher serum peak levels of both daidzein (P < 0.001) and genistein (P < 0.01) and the associated area under the curve (P < 0.001 and P < 0.03, respectively) compared with textured vegetable protein (predominantly isoflavone glucosides). However, soy milk was absorbed faster and peak levels of isoflavones were attained earlier than with the other soy foods. Only 30% of the subjects were equol producers and no differences in equol production with age or gender were observed.     

Effects of Colesevelam HCl on Sterol and Bile Acid Excretion in Patients with Type IIa Hypercholesterolemia

Colesevelam HC1 is a potent bile acid-binding polymer. This study's aim was to determine effects of colesevelam HCl on sterol and bile acid excretion in patients with type IIa hypercholesterolemia. Twenty-four patients (low-density lipoprotein cholesterol, 130 to 220 mg/dL) enrolled in an open-label, parallel-design study, entered an American Heart Association/National Cholesterol Education Program diet for 6 weeks and were randomized to colesevelam HCl, 2.3 or 3.8 g/day for 4 weeks. In an apparent dose-related manner, respective mean serum concentrations HCl of low-density lipoprotein cholesterol decreased by 10% (P < 0.01) and 13% (P = 0.05), mean total cholesterol levels decreased by 4.9% (P = 0.05) and 6.1% (P = 0.09), and total fecal bile acid excretion showed median changes of +324% (P < 0.05) and +316% (P < 0.05). Colesevelam HCl did not affect fecal neutral sterol or fecal fatty acid excretion; however, 24-hr urinary mevalonic acid levels significantly increased in both treatment groups (P < 0.05). The cholesterol-lowering action of colesevelam HCl appears to be mediated through increased bile acid excretion.     

Interleukin-18 is expressed in rat testis and may promote germ cell growth

Although host-defence mechanisms, designed to preserve the integrity of the developing germ cells are operative in the testis, the components of this protective system have yet to be characterised in detail. Here, we report that the cytokine interleukin-18 (IL-18) is expressed in the rat testis and may contribute to these defences. Thus, analysis by RT-PCR and Western blotting revealed pronounced testicular expression of pro-IL-18 from postnatal day 5 and onwards. Expression of both IL-18 mRNA and protein was found to be localised to meiotic and post-meiotic germ cells as evaluated by in situ hybridisation and immunohistochemistry, respectively. The mRNA species coding for the IL-18 receptor and IL-1β converting enzyme, which activates pro-IL-18, were also shown to be expressed by the seminiferous tubules. Recombinant IL-18 was seen to stimulate spermatogonial DNA synthesis in cultures of staged segments of rat seminiferous tubules, without influencing germ cell apoptosis. These results suggest that IL-18 may have host-protective and growth-promoting functions in the testis, but further investigations need to be done to confirm this.     

Outbreak of Pneumococcal Pneumonia among Military Recruits

Background

Between 04 Mar 2002 to 21 Mar 2002, 31 cases of pneumonia were admitted at a military hospital in South India. Most of these cases were young recruits. The out break was investigated to ascertain the cause and suggest preventive measures.

Methods

Detailed epidemiological history was taken from all 31 cases and 100 controls. Case sheets, laboratory reports and chest radiographs were studied. Laboratory investigations included sputum examination by Gram stain and blood cultures on brain heart infusion broth. Cultures grown on liquid media were subcultured on solid media. The regimental centre was visited to note the living and environmental conditions.

Results

Epidemiological investigations revealed overcrowding in the regimental centre. The space per recruit was below recommended standards. 51.6% of recruits who contacted pneumonia were sleeping on double deckers as compared to 21% of healthy controls. Blood culture was positive for Streptococcus pneumoniae in 25.8% of the cases. Chest radiograph showed consolidation typical of lobar pneumonia in 67% of the cases.

Conclusion

The outbreak of pneumococcal pneumonia occurred due to overcrowding. Chilly weather conditions and stress were contributing factors.Key Words: Military recruits, Outbreak, Overcrowding, Pneumococcal, Pneumonia