Materials and Methods: Freshly extracted mandibular teeth with sample size of thirty were carefully chosen and instrumented using the 2Shape and WOG rotary files. Preoperative and postinstrumentation cone-beam computed tomographic scans were done to accomplish mesial and distal dentin walls' measurements and volume of removed dentin calculations, apical transportation, and centering ratio. Statistical analysis was performed and confirmed by independent t-test. Statistical significance was set at 5%.
Results: When shaping ability of 2Shape and WOG was evaluated, it was reported that there was no statistically significant differences noted among the groups in relation to the total volume of removed dentin, apical transportation, and centering ratio.
Conclusion: It can be concluded that 2Shape and WOG preserved the original canal anatomy well and did not eliminate excess dentin during shaping and cleaning. Rotary nickel-titanium files which work on the principle of rotary movement attained an outcome analogous to that of the rotary files working on reciprocating motion in relation to alteration in angle.
AIM: To present a systematic review of nursing research that uses SEM.
DISCUSSION: The review revealed poor reporting of information about the determination of sample size, missing data, normality and outliers. Most studies neither computed composite reliability nor assessed convergent and discriminant validity. There was a lack of consistency in performing the analysis. Some of the studies conducted exploratory factor analysis before performing confirmatory factor analysis, without discussing its necessity. Although most studies declared the estimation method and software used, there were many that did not.
CONCLUSION: Little information about the different steps of conducting SEM analysis was provided in the studies. Weaknesses and areas of improvement for future empirical SEM studies were identified.
IMPLICATIONS FOR PRACTICE: When conducting SEM, there are many issues that should be addressed. Overlooking these issues may invalidate findings. The results of this review provide nurse researchers with best practice guidelines for conducting SEM and pave the way for researchers to adopt this method in their studies.
Methods: Manual sample size calculation using Microsoft Excel software and sample size tables were tabulated based on a single coefficient alpha and the comparison of two coefficients alpha.
Results: For a single coefficient alpha test, the approach by assuming the Cronbach's alpha coefficient equals to zero in the null hypothesis will yield a smaller sample size of less than 30 to achieve a minimum desired effect size of 0.7. However, setting the coefficient of Cronbach's alpha larger than zero in the null hypothesis could be necessary and this will yield larger sample size. For comparison of two coefficients of Cronbach's alpha, a larger sample size is needed when testing for smaller effect sizes.
Conclusions: In the assessment of the internal consistency of an instrument, the present study proposed the Cronbach's alpha's coefficient to be set at 0.5 in the null hypothesis and hence larger sample size is needed. For comparison of two coefficients' of Cronbach's alpha, justification is needed whether testing for extremely low and extremely large effect sizes are scientifically necessary.
MATERIALS AND METHODS: The calculated sample size was 128 subjects. The crown width/height, arch length, arch perimeter, and arch width of the maxilla and mandible were obtained via digital calliper (Mitutoyo, Japan). A total of 4325 variables were measured. The sex differences in the crown width and height were evaluated. Analysis of variance was applied to evaluate the differences between arch length, arch perimeter, and arch width groups.
RESULTS: Males had significantly larger mean values for crown width and height than females (P ≤ 0.05) for maxillary and mandibular arches, both. There were no significant differences observed for the crown width/height ratio in various arch length, arch perimeter, and arch width (intercanine, interpremolar, and intermolar) groups (P ≤ 0.05) in maxilla and mandible, both.
CONCLUSIONS: Our results indicate sexual disparities in the crown width and height. Crown width and height has no significant relation to various arch length, arch perimeter, and arch width groups of maxilla and mandible. Thus, it may be helpful for orthodontic and prosthodontic case investigations and comprehensive management.