PURPOSEThe purpose of this report was to evaluate the effect of the fabrication method and material type on the fracture strength of provisional crowns.MATERIALS AND METHODSA master model with one crown (maxillary left second premolar) was manufactured from Cr-Co alloy. The master model was scanned, and the data set was transferred to a CAD/CAM unit (Yenamak D50, Yenadent Ltd, Istanbul, Turkey) for the Cercon Base group. For the other groups, temporary crowns were produced by direct fabrication methods (Imident, Temdent, Structur Premium, Takilon, Systemp c&b II, and Acrytemp). The specimens were subjected to water storage at 37℃ for 24 hours, and then they were thermocycled (TC, 5000×, 5-55℃) (n=10). The maximum force at fracture (Fmax) was measured in a universal test machine at 1 mm/min. Data was analyzed by non-parametric statistics (α=.05).RESULTSFmax values varied between 711.09-1392.1 N. In the PMMA groups, Takilon showed the lowest values (711.09 N), and Cercon Base showed the highest values (959.59 N). In the composite groups, Structur Premium showed the highest values (1392.1 N), and Acrytemp showed the lowest values (910.05 N). The composite groups showed significantly higher values than the PMMA groups (P=.01).CONCLUSIONComposite-based materials showed significantly higher fracture strengths than PMMA-based materials. The CAD-CAM technique offers more advantages than the direct technique.

PURPOSEThis study investigated the influence of surface conditioning procedures and repeated firings on monoclinic content and strength of zirconia before cementation.MATERIALS AND METHODSSintered bar-shaped zirconia specimens were subjected to no surface treatment (control), air abrasion, or grinding (n=21). Their roughness was evaluated using a profilometer, and microscope analysis was performed on one specimen of each group. Then, 2 or 10 repeated firings (n=10) were executed, the monoclinic content of specimens was analyzed by X-ray diffraction, and a three-point flexural strength test was performed. Surface roughness values were compared using one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests, the monoclinic content values were tested using Kruskal-Wallis and Mann-Whitney U tests, and the flexural strength values were tested using two-way ANOVA and Tukey HSD tests (P=.05). Spearman's correlation test was performed to define relationships among measured parameters.RESULTSSurface-treated specimens were rougher than untreated specimens and had a higher monoclinic content (P<.005), and the relationship between roughness and monoclinic content was significant (P<.000). Neither surface treatment nor firing significantly affected the flexural strength, but Weibull analysis showed that for the air-abraded samples the characteristic strength was significantly lower after the 10th firing than after the 2nd firing.CONCLUSIONAfter firing, a negligible amount of monoclinic content remained on the zirconia surfaces, and rougher surfaces had higher monoclinic contents than untreated surfaces. Multiple firings could be performed if necessary, but the fracture probability could increase after multiple firings for rougher surfaces.

FS laser is an effective surface treatment for roughening surfaces of zirconia ceramics. Furthermore, it reveals the highest MPa.

The aim of this study was to investigate the influence of denture cleansers on surface roughness (Ra, µm) of two hard permanent reline resins and a conventional acrylic denture base resin. Fifty specimens of each material, measuring 10 mm×2 mm were randomly divided into 1 control and 4 experimental subgroups (n=10). Surface roughness values were measured using profilometer before and after immersion in distilled water and in 4 different denture cleansers for 8 h for 140 days. The Kruskal Wallis and Wilcoxon Signed Ranks tests were used for comparison among groups with a significance level of α=0.05. Immersion in denture cleansers significantly increased the surface roughness of reline resins and the difference among the cleansers was statistically significant (p=0.059). Denture cleansers can cause significant surface roughness alterations on hard permanent reline resins and denture base resin where their effect may differ according to the selected resin material.

Context:Polycystic ovary syndrome (PCOS) is an important cause of infertility. In women with PCOS have increased rate of spontaneous abortion and reduced rate of conception. HOXA–10 and HOXA–11 are proteinous products of homeobox gene group and play an important role during implantation.Aims:The aim of this study was to evaluate endometrial receptivity by measuring HOXA–10, HOXA–11, and leukemia inhibitory factor (LIF) gene expressions in women with PCOS.Settings and Design:A tertiary referral center.Materials and Methods:This study was conducted on reproductive age women with abnormal uterine bleeding without sonographically proven anatomical reason. Endometrial sampling procedures were done in proliferative phase using low-pressure endometrial suction device to exclude endometrial pathology. HOXA–10, HOXA–11, and LIF gene expressions were measured from endometrial sampling material. Blood sample was taken to measure serum estradiol level on the day of endometrial sampling.Statistical Analysis Used:Statistical analysis was performed using SPSS software version 17 (SPSS Inc., Chicago, IL, USA). Mann–Whitney U-test was used to compare the variables.Results:A total of 53 patients were included in this study. Study group consisted of 33 patients with PCOS. Gene expressions of HOXA–10, HOXA–11, and LIF were significantly lower in patients with PCOS (P < 0.05).Conclusions:This study results showed that in patients with PCOS have decreased gene expression of HOXA-10, HOXA-11, and LIF which might contribute PCOS-related infertility.