Compressive strength, surface roughness, and surface microhardness of principle tricalcium silicate-based endodontic cements after universal adhesive application.

Aims and Background: It was aimed to evaluate compressive strength (CS), surface roughness, and microhardness of mineral trioxide aggregate (ProRoot MTA) and Biodentine (BD) after adhesive application. Materials and Methods: Tests was carried out according to international ISO standard. ProRoot MTA and BD were prepared in Teflon molds according to manufacturer's instructions: n = 210 for CS; n = 210 for microhardness. Samples were incubated for 7 days at 37°C in 100% humidity. Surfaces were smoothed with up to 2000 grits of silicon-carbide sandpaper on abrasive device at 150 rpm, randomly divided into seven groups (n = 15). Clearfil Universal Bond, All Bond Universal, and Single Bond Universal (SBU) were applied in both total-etch and self-etch (SE) modes. Adhesives were applied according to manufacturers' recommendations (no adhesive used in control). CS was performed at speed of 1 mm/min, microhardness at 100 gr for 15 s. The surface roughness of the samples was analyzed with atomic force microscopy. Two-way analysis of variance and post hoc Tukey tests were used for the evaluation of the data. Results: Man CS and microhardness values between ProRoot MTA and BD were as follows: 24.9 N, 72.6 HV; 59.8 N, 59.0 HV, respectively. In CS, BD was higher than ProRoot MTA (P < 0.05). In other comparisons except for SBU SE group (P < 0.05), BD and ProRoot MTA showed similar results (P > 0.05). However, ProRoot MTA was found higher than BD regarding microhardness (P < 0.05). As a result of the adhesive application in both BD and ProRoot MTA groups, a decrease in surface roughness was observed compared to the control group. Conclusion: BD exhibited better results than ProRoot MTA regarding CS. However, ProRoot MTA was found to be more successful than BD in terms of microhardness. BD and ProRoot MTA showed similar physical properties in terms of surface roughness. To improve regenerative procedures, besides the selection of bioceramic cements, the interaction between cements and materials applied during coronal restoration should be considered.

Cyclic fatigue resistance of waveone gold, protaper next and 2shape nickel titanium rotary instruments using a reliable method for measuring temperature.

OBJECTIVE: The purpose of this study was to evaluate the cyclic fatigue resistances of the WaveOne Gold (WOG), ProTaper Next (PTN), 2Shape (TS) instruments. MATERIALS AND METHODS: Totally 45 new WOG (25/.07), PTN (25/.06), TS (25/.06) files were tested inside the artificial canal of a custom-made stainless steel block with an inner diameter of 1.5 mm, a 60° angle, and a 5-mm radius of curvature. A 16-mm-long file segment (from the tip) was introduced and was immersed in 37°C water. The number of cycles to fracture (NCF), time to failure (TTF), fractured fragment length (FL) was recorded and the fractured surface was examined using microscope. RESULTS: WOG > PTN > TS according to TTF results (P = 0.00). PTN > TS according to NCF results (P = 0.00). The FL values showed no significant difference (P = 0.335). CONCLUSIONS: Reciprocating motion can be used more safely than continuous rotation due to the higher cyclic fatigue resistance.

Ultrasonographic evaluation of thyroid nodules: comparison of ultrasonographic, cytological, and histopathological findings.

Thyroid ultrasonography (US) and fine needle aspiration biopsy (FNAB) are the most important tools in evaluating thyroid nodules. A total of 3,404 nodules in 2,082 cases referred to our clinic between 2005 and 2008 were analyzed retrospectively. Considering US features of nodules, risk factors predicting malignancy were: margin irregularity as the most important predictor, hypoechoic pattern and microcalcification (Odds ratios: 63.2, 13.3, 7.03, respectively). Cytologic results of the patients were as follows: 1,718 (82.5%) benign, 196 (9.4%) suspicious, 68 (3.3%) nondiagnostic, and 100 (4.8%) malignant. In histopathologic examination, we determined a malignancy rate of 7.59% (158/2082). We calculated the sensitivity of FNAB as 89.16%, specificity as 98.77%, positive predictive value as 96.10%, negative predictive value as 96.39%, and accuracy as 96.32%. In cytologic examination, the malignancy rate of subcentimetric (≤1 cm) nodules was higher than supracentimetric (>1 cm) nodules (5.1% vs. 1.5%, P = 0.001). In postoperative histopathologic examination, although the malignancy rate of subcentimetric nodules was higher than that of supracentimetric nodules, the difference was statistically insignificant (5.5%, 4.4%, respectively; P > 0.05). Cytologically diagnosed malignancy was detected in 4.5% of patients with multiple nodules, while it was present in 6% of patients with solitary nodule indicating no significant difference. However, postoperative histopathologic examination revealed a significantly higher malignancy rate in patients with solitary nodule compared to in patients with multiple nodules (11.7%, 6.5%; respectively, P < 0.001). The malignancy rate of patients operated for suspicious cytology was found to be 46.15%; for nondiagnostic cytology, it was 64.29%. In conclusion, ultrasonographically, hypoechoic pattern, microcalcification and margin irregularity of thyroid nodules are important features in determining the malignancy risk. The nodule size alone still remains inadequate to exclude malignancy risk.

Gastric pseudolipomatosis, usual or unusual? Re-evaluation of 909 endoscopic gastric biopsies.

Microvesicular pneumatosis intestinalis, also called "pseudolipomatosis" for resembling fatty infiltration, is characterized by the presence of small gas voids in the gastrointestinal wall, especially in mucosa. These voids are not lined with epithelia. There are few reported cases about colon, duodenum and skin. Because there is only one case report about pseudolipomatosis in the stomach, we re-evaluated 909 endoscopic biopsies taken from gastric corpus to check the presence of pseudolipomatosis. We determined pseudolipomatosis foci in 3 percent (n=27) of biopsies. In two cases there were pseudolipomatosis foci in endoscopic biopsies having otherwise normal histologic findings, while there were pseudolipomatosis foci in endoscopic biopsies of 25 patients with gastritis. H pylori was found in 85% of biopsies having pseudolipomatosis foci. In this study, we presented some histopathologic characteristics of pseudolipomatosis seen in gastric mucosa.