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Tukey's HSD Test (tukey + hsd_test)
Selected AbstractsEffects of surface treatments on bond strength of glass-infiltrated ceramicJOURNAL OF ORAL REHABILITATION, Issue 9 2001Y.-C. Lu The purpose of this study was to evaluate the effects of various surface treatments on the bond strength at the In-Ceram/resin composite interface. Ninety-eight In-Ceram specimens were divided into seven groups and exposed to various surface treatments as follows: (A) control (B) saliva contamination (C) saliva contamination plus aluminum oxide sandblasting (D) glove powder contamination (E) glove powder contamination plus aluminum oxide sandblasting (F) rough aluminum oxide sandblasting and (G) excess glass infiltration. A resin composite cylinder was cemented to each In-Ceram specimen with Panavia 21 resin luting cement. Half of the cemented specimens in each group were stored in water for 24 h, and the other half were stored in water for 2 weeks and then were thermo-cycled for 2000 cycles. Shear bond strengths (SBS) of seven specimens in each subgroup were determined and analysed using analysis of variance (ANOVA) and Tukey HSD test as well as Student,s t -test. Scanning electronic microscopy was used to identify the type of bond failure. Shear bond strength was significantly decreased by saliva and glove powder contaminations (P < 0·05). Sandblasting treatment did not improve the saliva-contaminated specimens. However, the glove powder plus sandblasting group showed no significant difference in SBS compared with the control group. There was no significant difference in SBS between the excess glass-infiltrating group and the control group. The SBS was significantly decreased by rough aluminum oxide sandblasting (P < 0·05). The SBS values of groups without thermocycling were significantly greater than those of groups with thermocycling (P < 0·05). There were no significant differences among SBS values of the seven groups with thermocycling. Combined cohesive and adhesive bond failures were seen in every group. Various surface treatments or contaminants may significantly influence the bond strength of In-Ceram restorative in clinical use. [source] Effect of body position on foot and ankle volume in healthy subjectsCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 6 2004Ivy O. W. Man Summary Physical therapy treatments for and evaluation of lower limb swelling are usually performed in supine lying position. However, the limb is usually treated or assessed in the dependent position, i.e. sitting or standing. The purpose of this study was to determine the possible confounding effect of subject positioning on foot and ankle volume. Sixty healthy individuals were randomly positioned into motionless standing, sitting or supine lying for 30 min. Volumetric measurements of the dominant leg were taken with a foot and ankle volumeter before and after 30 min of positioning. A significant difference between the three groups for foot and ankle volume change (F2,53 = 35·41, P<0·001) was found. A post-hoc Tukey HSD test revealed that the difference was statistically significant between sitting and standing as well as supine lying and standing (P<0·001). No statistical significance was found between sitting and supine lying (P = 0·90). Standing caused the greatest increase in foot and ankle volume followed by sitting then supine lying. The results indicate that treating or assessing a limb with the subject in a sitting position would not be significantly different from a subject who is positioned in supine lying. However, it is not known whether the height and the distance from the heart to the feet were comparable between the groups, and so it is recommended that, where possible, treatment and assessment of lower leg swelling should be undertaken with the leg in a non-dependent position and definitely not in standing. [source] Distance from file tip to the major apical foramen in relation to the numeric meter reading on the display of three different electronic apex locatorsINTERNATIONAL ENDODONTIC JOURNAL, Issue 12 2009R. A. Higa Abstract Aim, To establish and compare the relationship between the distance from the file tip to the apical foramen and the numeric meter reading on the display of three different electronic apex locators (EALs). Methodology, A total of 12 extracted intact, straight, single-rooted human teeth with complete roots were used. The actual root canal length (AL) was determined after access preparation. For the electronic measurements with each EAL, silicon stops were fixed with auto-polymerizing resin to size 15 K-files at AL and 0.5, 1, 2, 3, 4 mm short of AL. The data was analysed by two-way anova and Tukey's honestly significant difference (HSD) test for multiple comparisons amongst EALs. Additionally, one-way anova and Tukey's HSD test were carried out for multiple comparisons amongst the measurements of each EAL. Results, There was a statistically significant difference amongst all EALs in indicating the position of file tips in relation to the major foramen (P < 0.05). The correlation between the meter reading and the position of the file tip from the apical foramen was statistically significant in the three EALs. There were significant differences amongst the measurements at distances from 0 to 2 mm in Justy III. In Dentaport, significant differences were found from 0 to 1 mm. However, the E-Magic Finder showed significant differences from 0 to 0.5 mm. Conclusions, Justy III was more capable of displaying the intracanal position of the file tip from the major foramen in mm whilst advancing through the root canal during electronic measurements than the Dentaport and E-Magic Finder Deluxe. [source] The Effect of Denture Cleansing Solutions on the Retention of Yellow Hader Clips: An In Vitro StudyJOURNAL OF PROSTHODONTICS, Issue 3 2007Reena M. Varghese DMD Purpose: To evaluate the retention of yellow Hader clips after exposure to various denture cleansers. Methods: Seven groups of 18 yellow Hader clips each were soaked for the equivalent of 6 months of clinical use in the following denture cleansing solutions: Polident Regular, Polident Overnight, Efferdent, 5.25% Sodium Hypochlorite (NaOCl, 1:10 dilution) 15 min/day, NaOCl (1:10 dilution) 8 hours/day, water and dry (control) group. A Universal Testing Machine, set at a crosshead speed of 2 in/min, pulled each clip once, and the peak load-to-dislodgement was recorded and used as a measure to reflect changes in the retention of the Hader clips. Data were analyzed by a one-way analysis of variance followed by Tukey's HSD test. A p value , 0.05 was considered significant. Results: Denture cleansing solutions affected the retentive values of yellow Hader clips (F= 6.102, p, .0001). Sodium hypochlorite solution, 15 min/day for 6 months, caused an increase in the retentive values of the clips tested with a mean peak load-to-dislodgement of 22.63 ± 1.29 N. In addition, clips soaked in water showed no difference in retentive values when compared with all other groups. Furthermore, Polident Regular, Polident Overnight, Efferdent, and NaOCl (8 hours/day) had no effect on the retentive values of yellow Hader clips. Conclusion: This in vitro study demonstrated that the retention of yellow Hader clips used in implant overdentures is unaffected when soaked in commercial effervescent denture cleansers (Polident 5 Minute, Polident Overnight, and Efferdent) for six simulated months. Sodium hypochlorite statistically increased the single-pull retentive values of the clips, an effect that may not be beneficial. Increased retentive values may be associated with reduced durability of clips; further research is needed to address this issue. [source] Spontaneous recovery of an intensively used grassland after cessation of fertilizingAPPLIED VEGETATION SCIENCE, Issue 4 2009Josef Královec Abstract Questions: (1) Does a fertilized grassland recover in terms of species composition and species richness after stopping the treatment? (2) Which species contributed most to the changes? (3) Is it realistic to rely upon spontaneous recovery in this and similar cases? Location: A large grassland, located in the western part of the Czech Republic in central Europe, latitude 49° 59,, longitude 12° 45,, altitude 750 m a.s.l. Methods: Experimental plots of 2.5 m × 6.0 m were established in the central part of the grassland in 1968 using a randomized block design with the following variants: unfertilized controls, 80, 160, 240 and 320 kg ha,1 of nitrogen, in four or eight (320 kg) replicates. The fertilization regime was stopped in 1989. Phytosociological relevés of 2 m × 4 m in size were made in 1990, 1994, 1996, 1997, 1999, 2003 and 2006. The data were processed by multivariate ordination methods (DCA, CCA). Differences in the number of species per plot were tested by repeated measures anova and Tukey's HSD test. Results: All plots, including controls, exhibited a distinct trajectory through time, reflecting the rates of fertilizer used and generally changing in the same direction. Both time and nutrients significantly influenced the vegetation pattern. Treatments differed significantly in species richness, especially at the beginning of the observation. Differences in later years were less pronounced, thus a convergence between the treatments was evident. Conclusions: During the 16 years after fertilization ceased, the number of species substantially increased not only in the fertilized plots but also in the controls. Species typical of semi-natural grasslands predominantly contributed to the increase. Spontaneous recovery after cessation of fertilizing was relatively efficient, but the fertilized plots were small in size and thus rather easily colonized from outside. For interpretation and extrapolation of results from small experimental plots, it is necessary to consider changes in the broader surroundings. [source] | ||||||||||