The efficacy of two rotary NiTi instruments and H-files to remove gutta-percha from root canals

Objective: The aim of this study was to evaluate the efficacy of R-Endo® and K3® rotary nickel-titanium instruments compared with manual instrumentation with H-files, with use of a solvent, for removal of gutta-percha during retreatment. Study design: Forty five freshly extracted human single-rooted teeth, each with one root canal, were instrumented with K-files and filled using cold lateral compaction of gutta-percha and AH 26® sealer. The teeth were randomly divided into three groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: Group 1 (H-files), Group 2 (R-Endo®), and Group 3 (K3®). The specimens were rendered transparent for the evaluation of the area of remaining gutta-percha/sealer in buccolingual and mesiodistal directions. Statistical analysis as performed by using one-way ANOVA and Kruskal-Wallis tests (p=0.05). Results: All retreatment techniques used in this study left some filling material inside the root canal. Images in buccolingual and mesiodistal directions showed no significant differences between the groups (p>0.05). Conclusions: Under the experimental conditions, the remaining filling material after retreatment was similar for each group

Employment generation by small firms in Spain

Despite the relevance in terms of policy, we still know little in Spain about where and by whom jobs are created, and how that is affecting the size distribution of firms. The main innovation of this paper is to use a rich database that overcomes the problems encountered by other firm-level studies to shed some light on the employment generation of small firms in Spain. We find that small firms contribute to employment disproportionately across all sectors of the economy although the difference between their employment and job creation share is largest in the manufacturing sector. The job creators in that sector are both new and established firms whereas only new small firms outperform their larger counterparts in the service sector. The large annual job creation of the small firm size class is shifting the firm size distribution towards the very small production units, although not uniformly across industries of different technology intensit

Estimation of carcass composition and fat depots by means of subcutaneous adipocyte area and body and tail measurements in fat-tailed Akkaraman lambs

This study was conducted to establish prediction equations for subcutaneous adipocyte area and body and tail measurements to estimate carcass composition and fat depots of indigenous Akkaraman lambs. As a major carcass tissue, body fat depots play an important role in deciding the optimum slaughter weight and grading of the carcass and meat quality. In this respect, forty male Akkaraman lambs were slaughtered and dissected to define the partitioning of fat among body depots after recording the body and tail measurements and taking adipose tissue samples. Mean cold carcass weight was 19.8 kg with a composition of 48.9% muscle, 30.3% fat, 19.6% bone and 1.2% waste. The dressing percentage was 48.4 %. Tail fat, subcutaneous fat and intermuscular fat were the major fat depots with overall means of 15.3%, 10.2% and 4.9%, respectively. Heart girth had the highest correlation (r = 0.91) with total body fat, while tail circumference had the highest correlation (r = 0.72) with total body fat among the tail measurements. Correlation coefficients were also high between the adipocyte area and cold carcass (r = 0.84), total body fat (r = 0.84) and carcass fat (r = 0.86) values. The established regression equations showed that tail fat (R2 = 0.81), carcass fat (R2 = 0.89) and total body fat (R2 = 0.93) weights could be predicted with a high accuracy. It is concluded that carcass composition and body fat depots could be estimated with a high degree of accuracy by establishing the regression equations based on the adipocyte area and external measurements of the body and tail in Akkaraman lambs. Keywords: Adipose tissue; carcass fat; regression; sheep South African Journal of Animal Science Vol. 38 (4) 2008: pp. 282-28