Comparison between two methods of working length determination and its effect on radiographic extent of root canal filling: a clinical study [ISRCTN71486641]

BACKGROUND: Obtaining a correct working length is critical to the success of endodontic therapy. Different methods have been used to identify this crucial measurement. The Aim of this clinical study was to compare the effect of working length determination using apex locator alone or in combination with working length radiograph on the apical extent of root canal filling. METHODS: A total number of 66 patients, 151 canals were randomized into two groups, In group (I) working length was determined by apex locator alone, while in group (II) working length was determined by apex locator confirmed by working length radiograph, length of obturation was assessed, and the total number of radiographs was recorded. The data were analyzed using SAS system and T. tests were carried out. Statistical significance was considered to be P ≤ 0.05. RESULTS: Sixty seven canals in group I were treated with a mean distance from the tip of root canal filling to radiographic apex -0.5 mm ± 0.5 and a mean of a total number of radiographs of 2.0, while in group II eighty four canals were treated with a mean distance from the tip of root canal filling to radiographic apex -0.4 mm ± 0.5 and a mean of a total number of radiographs of 3.2. There was no statistically significant difference in the mean distance from the tip of root filling to radiographic apex between group I and group II (P > 0.05). CONCLUSION: The practice of using electronic apex locator in the determination of working length is useful and reliable with no statistical difference of the radiographic extent of root canal filling when using apex locator alone or in combination with working length radiograph. Under the clinical conditions of this study, it is suggested that the correct use of an apex locator alone could prevent the need for further diagnostic radiographs for determination of working length. This method can be useful in patients who need not to be exposed to repeated radiation because of mental, medical or oral conditions

Morphometric study of the root anatomy in furcation area of mandibular first molars

Furcation involvement in periodontal disease has been a challenge for the dentist. OBJECTIVE: The aim of this study was to investigate root dimensions in the furcation area of 233 mandibular first molars. MATERIAL AND METHODS: Digital photomicrographs were used to obtain the following measurements on the buccal and lingual surfaces of each tooth: root trunk height (RT), horizontal interadicular distance obtained 1 mm (D1) and 2 mm (D2) below the fornix and interadicular angle (IA). RESULTS: Mean± standard deviation of buccal and lingual furcation measurements were, respectively, 1.37±0.78 mm and 2.04±0.89 mm for RT; 0.86±0.39 mm and 0.71±0.42 mm for D1; 1.50±0.48 mm and 1.38±0.48 mm for D2; 41.68±13.20º and 37.78±13.18º for IA. Statistically significant differences were found between all measured parameters for buccal and lingual sides (p<0.05, paired t test). CONCLUSIONS: In conclusion, the lingual furcation of mandibular first molars presented narrower entrance and longer root trunk than the buccal furcation, suggesting more limitation for instrumentation and worse prognosis to lingual furcation involvements in comparison to buccal lesions

Do Political Attitudes Matter for Epistemic Decisions of Scientists?

The epistemic attitudes of scientists, such as epistemic tolerance and authoritarianism, play important roles in the discourse about rivaling theories. Epistemic tolerance stands for the mental attitude of an epistemic agent, e.g., a scientist, who is open to opposing views, while epistemic authoritarianism represents the tendency to uncritically accept views of authorities. Another relevant epistemic factor when it comes to the epistemic decisions of scientists is the skepticism towards the scientific method. However, the question is whether these epistemic attitudes are influenced by their sociopolitical counterparts, such as the researcher's degree of conservatism. To empirically investigate the interplay between epistemic and sociopolitical attitudes of scientists, we conducted a survey with researchers (N = 655) across different disciplines. We propose scales for measuring epistemic tolerance and epistemic authoritarianism, as well as a scale for detecting the participants' readiness to question the scientific method. Furthermore, we investigate the relationship between epistemic tolerance and epistemic authoritarianism on the one hand, and career stage and sociopolitical views on the other hand. Interestingly, our study found only small correlations between the participants' degree of conservatism and their epistemic attitudes. This suggests that political views, against common argumentation, actually do not play an important role in one's scientific decisions. Moreover, social scientists scored higher on the epistemic tolerance and lower on the epistemic authoritarianism scale than natural scientists. Finally, the results indicate that natural scientists question the scientific method less than social scientists

Global variation in quality of care among patients hospitalized with acute heart failure in an international trial: Findings from the Acute Study Clinical Effectiveness of Nesiritide in Decompensated Heart Failure Trial (ASCEND-HF)

Background— Translation of evidence-based heart failure (HF) therapies to clinical practice is incomplete and may vary internationally. We examined common measures of quality of care in patients enrolled in the international Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure trial. Methods and Results— Patients were admitted to 398 hospitals for acute HF in 5 regions (North America, n=3149; Latin America, n=658; Asia Pacific, n=1744; Central Europe, n=966; and Western Europe, n=490). Predefined quality indicators assessed at hospital discharge included the following: medications (angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, β-blockers, aldosterone antagonists, hydralazine/nitrates, statin therapy, and warfarin), use (or planned use) of implantable intracardiac devices, and blood pressure control (&lt;140/90 mm Hg). We determined regional variations in quality indicators as well as the temporal variation of these indicators during the course of the trial. There was significant variation in conformity among different quality indicators, ranging from 0% to 89%. Of all potential performance opportunities, 19 076 of 32 268 (59%) were met, with Central Europe highest at 64%, followed by North America (63%), Western Europe (61%), Latin America (56%), and Asia Pacific (51%; P &lt;0.0001). North America, Central Europe, and Asia Pacific regions demonstrated a modest increase in quality indicator conformity over time, although there was no significant change in other regions. Conclusions— Quality of care for patients hospitalized with acute HF varies and remains suboptimal even within a randomized clinical trial, which included quality improvement interventions. Specific measures designed to improve performance measures should be implemented even within multicenter clinical trials. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00475852. </jats:sec