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The purpose of this study was to determine the number of samples that should be used in independent treatment comparisons with different effect sizes (0.25-3.0), the number of treatments (2-5), and the power of the test (70% -95%) in single and multi-factor treatments. The material of the study was the random numbers drawn from the population that shows a normal distribution with N (0, 1) parameter. The power of the test was calculated by sampling with replacement from the population and after the differences between the treatments in terms of standard deviation were established, 10000 simulations were performed. This setup was carried out for experiments with one, two, and three factors. In the comparison of single factor independent treatment means, when the effect size was larger than Δ = 2 and the test power was between 70% and 95%, the sample sizes varied between 3 and 7. In the comparison of two-factor independent treatment means, when the effect size was larger than Δ = 2 and the test power was between 70% and 95%, the sample sizes varied between 2 and 3. In the comparison of three-factor independent treatment means, when the effect size was larger than Δ= 1.5 and the test power was between 70% and 95%, the sample size was 2. If all treatment comparisons were generalized; it was observed that when the effect size increased, and the power of the test decreased, the sample size decreased In the t-test and F tests used in independent treatment comparisons, a power analysis was performed under different situations, and the number of experimental units for each 5% power increment between 70% and 95% were presented in tables. These tables, may help researchers to determine the number of samples without power analysis in independent group comparisons.

Objective: Microleakage is still one of the most cited reasons for failure of resin composite restorations. Alternative methods to prevent microleakage have been investigated increasingly. The aim of this study is to evaluate the microleakage in Class V resin composite restorations with or without application of surface sealants with different filler content. Materials and Methods: Ninety-six cavities were prepared on the buccal and lingual surfaces with the coronal margins located in enamel and the cervical margins located in dentin. The cavities restored with an adhesive system (Clearfil SE Bond, Kuraray, Tokyo, Japan) and resin composite (Clearfil Majesty ES-2, Kuraray, Tokyo, Japan). Teeth were stored in distilled water for 24 h and separated into four groups according to the surface sealants (Control, Fortify, Fortify Plus, and G-Coat Plus). The teeth were thermocycled (500 cycles, 5–55°C), immersed in basic fuchsine, sectioned, and analyzed for dye penetration using stereomicroscope. The data were submitted to statistical analysis by Kruskal–Wallis and Bonferroni–Dunn test. Results: The results of the study indicated that there was minimum leakage at the enamel margins of all groups. Bonferroni–Dunn tests revealed that Fortify and GC-Coat groups showed significantly less leakage than the Control group and the Fortify Plus group at dentin margins in lingual surfaces (P < 0.05). Conclusion: The all surface sealants used in this study eliminated microleakage at enamel margins. Moreover, unfilled or nanofilled surface sealants were the most effective in decreasing the degree of marginal microleakage at dentin margins. However, viscosity and penetrability of the sealants could be considered for sealing ability besides composition.

Objective The aim of this trial was to compare the alignment efficiency and intermaxillary arch dimension changes of nickel-titanium (NiTi) or copper-nickel-titanium (CuNiTi) round archwires with increasing diameters applied sequentially to the mandibular arch. Methods The initial alignment phase of fixed orthodontic treatment with NiTi or CuNiTi round archwires was studied in a randomly allocated sample of 66 patients. The NiTi group comprised 26 women, 10 men, and the CuNiTi (27℃) group comprised 20 women, 10 men. The eligibility criteria were as follows: anterior mandibular crowding of minimum 6 mm according to Little's Irregularity Index (LII), treatment requiring no extraction of premolars, 12 to 18 years of age, permanent dentition, skeletal and dental Class I malocclusion. The main outcome measure was the alignment of the mandibular anterior dentition; the secondary outcome measure was the change in mandibular dental arch dimensions during 12 weeks. Simple randomization (allocation ratio 1:1) was used in this single-blind study. LII and mandibular arch dimensions were measured on three-dimensional digital dental models at 2-week intervals. Results No statistically significant difference was observed between NiTi and CuNiTi according to LII (p > 0.05). Intercanine and intermolar arch perimeters increased in the CuNiTi group (p < 0.001). Inter-first premolar width showed a statistically significant interaction in week × diameter × application (p < 0.05). Conclusions The effects of NiTi and CuNiTi round archwires were similar in terms of their alignment efficiency. However, the intercanine and intermolar arch perimeters, and the inter-first premolar width changes differed between groups.

Bisphosphonates (BPs) like zoledronic acid (ZOL) are widely used for the treatment of different diseases such as osteoporosis, metastatic bone diseases and hypercalcaemia. However, the effects of BPs on apoptosis of the liver and kidney after treatment are unclear. Furthermore, basic fibroblast growth factor (bFGF) is an angiogenic molecule, which plays an important role in angiogenesis and tissue repair. The present study investigated the expression of caspase-3, -5, -7 and apoptotic protease-activating factor-1 (APAF-1) in the liver and kidney of rats treated with ZOL and bFGF.The present study investigated the expression of caspase-3, -5, -7 and apoptotic protease-activating factor-1 (APAF-1) in the liver and kidney of rats treated with ZOL and bFGF.An animal model with 32 male Sprague Dawley rats was used. The effects of ZOL and bFGF on liver and kidney with the expressions of different apoptosis markers were studied histopathologically and immunohistochemically. Data were analyzed using Cronbach's alpha, Kruskal-Wallis and Bonnferroni-Dunn tests.The main microscopic findings were mononuclear cell infiltrations around the bile ducts, binuclear and markedly enlarged hepatocytes (cytomegaly) and mitotic figures in the liver of rats treated with ZOL only. Immunohistochemically, both APAF-1 and caspase-3, -5 and -7 expressions were found elevated significantly (P0.05) in the liver and kidney of these rats.Our findings showed that ZOL treatment increased while bFGF treatment decreased apoptosis significantly in the liver and kidney of Sprague Dawley rats.The addition of bFGF to ZOL treatment of various diseases might reduce the ZOL effects.