Effects of Coloring Liquid Dipping Time and Surface Finishing Procedures on the Optical Properties of Monolithic Zirconia.

BACKGROUND: Monolithic zirconia restorations can be produced from self-colored or uncolored blocks. The coloring procedure of uncolored blocks and surface treatments may affect the appearance of the restoration. AIM: The purpose of this study is to evaluate the effect of liquid coloring and surface treatments on optical properties of translucent monolithic zirconia. METHODS: All specimens were cut from zirconia blocks with a thickness of 1 mm. Specimens were dipped in the coloring liquids for 3 min, 5 min, and 7 min and then divided into groups of 10 specimens for surface treatments. Glaze and mechanical polishing were applied, and the color of the specimens was measured under the D65 lighting condition with a spectrophotometer device. Color values obtained from the CIE Lab formula and the translucency parameter (TP), opalescence parameter (OP), and contrast ratio (CR) were calculated. The normality of the data was confirmed with the Shapiro-Wilk test. A three-way analysis of variance (ANOVA) was used to assess the effect of dipping time, liquid shade, and surface treatments. RESULTS: The effect of liquid shade and dipping time on the TP, OP, and CR parameters were statistically significant, and the TP values were reduced with the application of coloring liquid. Mechanical polishing groups had higher OP values and lower TP values than glazed groups. CONCLUSION: In cases where high translucency is required, it may be advisable to use self-colored blocks and apply glaze as a surface treatment to achieve the desired optical properties.

Clinical features, risk factors, and antimicrobial resistance of pseudomonas putida isolates.

Pseudomonas putida rarely results in infection, primarily in patients undergoing invasive procedures or immunocompromised hosts. We aimed to investigate the characteristics of Pseudomonas putida infections. This is a retrospectively designed cross-sectional observational study. We retrospectively scanned the data from our hospital for the 10 years before February 15, 2022. The patients with Pseudomonas putida growth in the microbiological cultures and with antibiotic susceptibility tests were included in the study. We recorded culture isolates types, age, gender, comorbidities, immunosuppressive factors, symptoms, invasive medical procedures, length of hospital stay, and radiological findings. The mean age of the patients was 66.2 ±â€…14.5 years, and the male patients predominated (76.3%, n = 58/76). There was growth in bronchial lavage in 33 patients, sputum in 28, pleural effusion fluid in 12, and tracheal aspirate in 3 patients. The rate of antibiotic-resistant strains was 56.6% (n = 43). All strains were sensitive to colistin (100%), and carbapenem, amikacin, and gentamicin sensitivity rates were high. We observed that the risk of antibiotic resistance increased 4.29 times in the patients in the intensive care unit (Cl:1.27-14.47, P = .01). The patients with Diabetes Mellitus had a higher risk (OR 4.33, Cl:1.11-16.77, P = .03), and in cancer cases, the risk was 3.31 times higher (Cl:1.06-10.32, P = .03). The risk of Pseudomonas putida infection should be considered, particularly in patients with comorbid disorders causing immunosuppression, including Diabetes Mellitus and Cancer.

How are the color parameters of a CAD/CAM feldspathic ceramic of the material affected by its thickness, shade, and color of the substructure?

OBJECTIVES: The purpose of this study was to evaluate the effect of the tooth color, ceramic color, and ceramic thickness on the final color parameters of a feldspathic computer-aided design (CAD)/computer-aided manufacturing (CAM) ceramic material. MATERIALS AND METHODS: Resin specimens (12 × 14 × 4 mm) were prepared from six shades, namely, 0M1S, 1M1S, 2M3S, 3M2S, 4M3S, and 5M3S, to simulate tooth color. Ceramic slices with thicknesses of 0.3, 0.5, 0.7, and 1 mm were sectioned from Vitablocs Mark II (12 × 14 × 18 mm) in 10 shades-OM1C, 1M1C, 1M2C, 2M1C, 2M2C, 2M3C, 3M1C, 3M2C, 3M3C, and 4M2C. An intraoral spectrophotometer was used and three axes of Commission Internationale de l'Eclairage (CIE) LAB color space (CIE L* a* b*) and chroma (C) and hue (H) values were obtained. RESULTS: The a* and b* values showed a decrease with increasing thickness. Generally, C decreased with the increasing ceramic thickness. The effect of ceramic thickness on H changed depending on the block and substructure color. The change of ceramic thickness resulted in changes in the lightness parameter (L*) of the ceramics. Generally, with an increase in the thickness, the L* value increased. The univariate analysis of variance (ANOVA) indicated a significant interaction between ceramic thickness and substructure color (P <. 005) and ceramic thickness and ceramic color (P <. 005). CONCLUSION: The final color parameters of a feldspathic CAD/CAM block were significantly affected by the changes in the ceramic thickness and substructure color.

Clinical evaluation of submerged and non-submerged implants for posterior single-tooth replacements: a randomized split-mouth clinical trial.

The aim of this study was to evaluate clinical and radiographic results of submerged and non-submerged implants for posterior single-tooth replacements and to assess patient-based outcomes. Twenty patients were included in the study. A split-mouth design was used; implants inserted using a submerged technique were compared to those inserted with a non-submerged technique. Implants were restored with metal-ceramic crowns after 3 months. Reconstructions were examined at baseline, 6, 12, and 24 months. Standardized radiographs were made. Radiographic crestal bone level changes were calculated, as well as soft tissue parameters, including pocket probing depth, bleeding on probing, plaque index, and gingival index. Results were analyzed by two-way repeated measures of variance (ANOVA). To evaluate patient-based outcomes, patients were asked to complete a questionnaire at the 6-month follow-up; the Wilcoxon paired signed rank test was used to compare scores. The data of 18 patients were reviewed. During 24 months, non-submerged implants (0.57 ± 0.21 mm) showed significantly lower bone loss than submerged implants (0.68 ± 0.22 mm) (P<0.01). Patient satisfaction with non-submerged implants (median 87.5) was significantly higher than with submerged implants (median 81.5) (P<0.01). Non-submerged implants showed comparable clinical results to submerged implants and resulted in higher patient satisfaction due to decreased surgical intervention.

Diagnostic performance of p16 staining in atypical squamous cells 'cannot exclude high-grade squamous epithelial lesion' in predicting high-grade cervical pathology.

Atypical squamous cells 'cannot exclude high-grade squamous epithelial lesion' (ASC-H) cytology represents clear risk and has been a controversial issue in clinical practice. The objective of this study is to investigate the diagnostic performance of p16(INK4A) immunohistochemistry (IHC) among ASC-H Pap smears in predicting high-grade cervical intraepithelial lesions. Decolourisation and staining process with p16(INK4A) is applied to 27 ASC-H diagnosed conventional Pap smears, which were all managed with colposcopy-directed cervical biopsy priorly. Staining characteristics of ASC-H Pap smears were compared with histopathological data and sensitivity-specificity values of p16 triage to detect CIN2 + histopathology were determined. The sensitivity and specificity of positive p16(INK4A) immune staining to detect CIN2 + histopathology were as 87.5% and 68%, respectively. The positive predictive value of p16 triage is found as 53.8% and negative predictive value was as 92.8%. p16(INK4A) IHC seems applicable for conventional Pap smears and may provide an alternative triage option in ASC-H category.

Comparison of laparoscopy and laparotomy in surgical staging of clinical early stage endometrial cancer: a report of early experiences from Turkey.

The objective of this study was to assess the feasibility of laparoscopy (LS) in endometrial carcinoma staging. Clinical early stage endometrial cancer patients (n = 153) staged by LS or laparotomy (LT) were compared. A total of 40 (26.1%) patients were treated by LS and 113 (73.9%) by LT. All patients underwent pelvic lymphadenectomy. Lymphadenectomy has been extended to para-aortic space in 55% of the LS group and 70% of the LT group. The majority of patients had stage I-II disease. The median numbers of removed pelvic and para- aortic lymph nodes were similar in two groups (p values 0.213 and 0.199, respectively). Body mass index (BMI) (kg/m(2)) was higher in the LT group (31.2 vs 27.4, p < 0.05). Operation time, age, tumour histology, para-aortic lymphadenectomy and complication rates were similar in the two groups. Four (10%) patients in the LS group and 12 (10.6%) in the LT group had recurrence of disease (p = 1.0). There was no statistical difference for overall survival between the two groups. In conclusion, these findings showed that in endometrial carcinoma cases, laparoscopy has provided adequate staging and similar survival rates with laparotomy.

Malign peritoneal mesothelioma with nephrotic syndrome.

Nephrotic syndrome may occur in malignancies like Hodgkin Disease and other solid tumors due to glomerulonephritis, amyloidosis or other causes. However, it is rare in peritoneal mesothelioma. We report a 42-year old female patient with peritoneal mesothelioma and nephrotic syndrome together with a review of literature (Tab. 1, Fig. 3, Ref. 7).

Effects of soldering and laser welding on bond strength of ceramic to metal.

STATEMENT OF PROBLEM: Welding or soldering of metal frameworks negatively affects the overall bond strength between the veneering ceramic and metal. PURPOSE: The purpose of this study was to evaluate the effect of soldering and laser-welding procedures on the bond strength between ceramic and metal. MATERIAL AND METHODS: Thirty Ni-based metal specimens (Wiron 99) (8 × 4 × 4 mm) were fabricated and divided into 3 groups; soldered (S), laser welded (L), and control (untreated cast alloy) (n=10). In S and L specimens, a notch (1 × 1.5 mm) was prepared longitudinally on the surface of each specimen and filled with compatible alloy (Wiron soldering rods and Wiroweld NC, respectively). Vickers hardness measurements were made after polishing the surfaces with a metallographic polishing kit. A veneering ceramic (VITA VMK 95) was vibrated, condensed in a mold, and fired on the metal frameworks. The specimens were sectioned in 2 axes to obtain nontrimmed bar specimens with a bonding area of approximately 1 mm². Forty bars per block were obtained. Each bar was subjected to microtensile bond strength (µTBS) testing with a crosshead speed of 1 mm/min. The µTBS data (MPa) were recorded, and SEM was used for failure analysis of the tested bars. The measurements were statistically analyzed using a 1-way ANOVA and Tamhane tests (α=.05). RESULTS: The mean differences in µTBS of veneering ceramic to soldered (10.4 ±2.4 MPa) and laser-welded (11.7 ±1.3 MPa) metal surfaces were not significantly different and were significantly lower than that of the cast alloy (25.4 ±3.6 MPa) (P<.05). The mean Vickers hardness of cast alloy was significantly higher (236 ±17 HV) than soldered (114 ±9 HV) and laser-welded groups (129 ±11 HV) (P<.05). CONCLUSIONS: Soldering and laser welding significantly decreased the µTBS of a veneering ceramic to a base metal alloy.

The role of telomerase activity in predicting early recurrence of epithelial ovarian cancer after first-line chemotherapy: a prospective clinical study.

PURPOSE OF INVESTIGATION: To investigate the value of telomerase activity (TA) in the detection of early recurrence in primary epithelial ovarian cancer (EOC). METHOD(S): In this study, TA was studied in 30 patients with Stage III EOC and 50 control patients with benign gynecological disease. All enrolled EOC patients had had primary cytoreductive surgery and six cycles of platinum-based first-line chemotherapy previously. Semi-quantative TA measurements were done by TRAP assay in ascites, taken at second-look surgery, of cancer patients and in peritoneal washings, taken during planned surgery, of the control group. RESULT(S): Early recurrence was diagnosed in ten EOC patients (33.3%). Mean TA was statistically higher in EOC patients than in patients with benign disease. However, the mean TA was insignificantly lower in early recurrent EOC patients than in disease-free EOC patients. CONCLUSION(S): The value of TA is limited in the detection of early recurrence in primary EOC.

Elastic-plastic finite elements analysis of transient and residual stresses in ceramo-metal restorations.

Transient and residual stresses occurring in partially fixed dental prostheses after the firing process can be calculated with elastic or elastic-plastic finite element analyses (FEA). In this study, firstly, the mechanical and thermal properties at various temperatures of the materials used in a porcelain fused metal (PFM) system were obtained by experimental and literature studies. The effects of viscoelastic and viscoplastic behaviours of the dental porcelain at the elevated temperatures were reflected onto its elastic properties. The equivalent heat transfer coefficients were determined experimentally by measuring temperatures and the results were supplied as input to the 3D finite elements analysis. It has been observed that the maximum stresses occur within a short time period after cooling begins and that stresses decrease during the cooling process and remain at a constant value at the end of cooling; these are the thermal residual stresses.

Open intramedullary Kirschner wire versus screw and plate fixation for unstable forearm fractures in children.

PURPOSE: To compare the outcomes of intramedullary Kirschner wire versus screw and plate fixation for unstable forearm fractures in children aged older than 10 years. METHODS: Records of 32 children aged 10 to 15 (mean, 12) years with displaced fractures of the radius and ulna were retrospectively reviewed. 17 boys and 4 girls underwent intramedullary Kirschner wiring, whereas 10 boys and one girl underwent plating. All patients had been initially treated with closed reduction and casting. Indications for surgical intervention were fractures with angulation of >10 degrees and total displacement. Patients were followed up for a mean of 24 (range, 13-40) months. Angulation and range of movements of the elbow, wrist, and forearm, as well as clinical and cosmetic results were compared. RESULTS: Both treatments achieved excellent clinical outcomes, but intramedullary Kirschner wiring resulted in better cosmesis, shorter operating times, easier hardware removal, and lower implant costs. CONCLUSION: Intramedullary Kirschner wiring is a better option than plating for the treatment of unstable forearm fractures in older children.

Evaluation of bond strength of various margin ceramics to a zirconia ceramic.

OBJECTIVE: This study evaluated the bond strengths of four different margin ceramics based on fluoroapatite and feldspath to a zirconia ceramic. METHODS: Zirconia cores (Zirconzahn) (N=28, n=7/margin ceramic group) were fabricated according to the manufacturers' instructions (diameter: 4mm; thickness: 2mm) and ultrasonically cleaned. Four different margin ceramics (thickness: 5mm) (Cerabien Zr, Noritake; Ceramco PFZ, Ceramco; e.max, Ivoclar Vivadent and Triceram, Dentaurum) were vibrated and condensed in a stainless steel mould and fired onto their zirconia cores. After trying the specimens in the mould for minor adjustments, they were again ultrasonically cleaned and embedded in PMMA. The specimens were stored in distilled water at 37 degrees C for 1 week and shear bond strength (MPa+/-S.D.) tests were performed in a universal testing machine (crosshead speed: 0.5mm/min). Failure modes were recorded under SEM. RESULTS: Significant effect of margin ceramic types were found on the bond strength values (P<0.05). The mean bond strength values of Ceramco margin ceramic to zirconia was significantly lower (25.4+/-4.5 MPa) (P<0.05) than those of Cerabien (31.6+/-6.4 MPa), e.max (35.9+/-8.4 MPa), and Triceram margin ceramic (38.8+/-7.1 MPa) systems. CONCLUSIONS: Margin ceramics, compatible with zirconia framework material tested in the present study, exhibited high bond strength values. Variations in thermal expansion coefficients might influence their bond strength values.

Current-induced stabilization of surface morphology in stressed solids.

We examine the surface morphological evolution of a conducting crystalline solid under the simultaneous action of an electric field and mechanical stress based on a fully nonlinear model and combining linear stability theory with self-consistent dynamical simulations. We demonstrate that electric current, through surface electromigration, can stabilize the surface morphology of the stressed solid against cracklike surface instabilities. The results also have more general implications for the morphological response of solid surfaces under the simultaneous action of multiple external forces.

The role of p53, Bcl-2 and Ki-67 in premalignant cervical lesions and cervical cancer.

PURPOSE: The aim of this study was to determine the role of p53, Bcl-2 and Ki-67 expression in the carcinogenesis of cervical carcinoma and aggressiveness of cervical intraepithelial neoplasia (CIN). METHODS: The pathology specimens of 63 patients with a diagnosis of normal squamous epithelium (22 cases), CIN I (14), CIN II (5), CIN III (8) and squamous cell carcinoma (14) were evaluated immunohistochemically for the expression of p53, Bcl-2 and Ki-67 in paraffin sections. RESULTS: The expression of p53 and Ki-67 increased proportionally to the grade of CIN and cervical cancer, but only the increase of p53 expression was statistically significant (p = 0.002). There was no significant correlation between Bcl-2 expression and premalignant and malignant cervical lesions. CONCLUSION: p53 expression may have a role in the carcinogenesis of squamous cell cervical carcinoma whereas Bcl-2 expression has no role. Ki-67 expression can not be used in determining the aggressiveness of CIN lesions.

Bond strengths of all-ceramics: acid vs laser etching.

Various applications of dental lasers on dental materials have been proposed for surface modifications. This study evaluated whether laser etching could be an alternative to hydrofluoric acid (HF) etching. One hundred and ten lithia-based all-ceramic specimens (Empress 2) (R: 4 mm, h: 4 mm) were prepared and divided into five groups (n = 22/group). The untreated specimens served as the control, while one of the experimental groups was treated with 9.5% HF for 30 seconds. Three remaining test groups were treated with different laser (Er:YAG laser wavelength:2940 nm, OpusDent) power settings: 300 mJ, 600 mJ and 900 mJ. Ten specimens in each group were luted to the other 10 specimens by a dual-curing cement (Variolink II), and shear-bond strength (SBS) tests were performed (Autograph, crosshead speed: 0.5 mm/minute). The results were statistically analyzed (Kruskal Wallis and Mann Whitney-U, alpha = .05). Mean SBS (MPa) were 31.9 +/- 4.0, 41.4 +/- 4.3, 42.8 +/- 6.2, 29.2 +/- 4.5 and 27.4 +/- 3.8 for the control and HF, 300, 600 and 900 mJ groups, respectively. SEM evaluations revealed different surface morphologies depending on the laser parameters. The differences between HF acid and 300 mJ, when compared with the control, 600 and 900 mJ groups, were significant (p < .05). The 300 mJ laser group exhibited the highest shear-bond strength values, indicating that laser etching could also be used for surface treatments.

Effect of temperature and stress distribution on all-ceramic restorations by using a three-dimensional finite element analysis.

This study presents the stress analysis of the mandibular first premolar tooth restored with an all-ceramic crown under thermal loading as a result of hot/cold liquid intake to the mouth using the three-dimensional (3D) finite element analysis (FEA). In the first step of the study, the temperature changes as a result of hot/cold liquid intake were calculated. The thermal stress distributions because of the temperature changes were then obtained. Thermal loads ranging from 60 to 15 degrees C were applied on all prepared models. The distribution of temperature and stress were plotted for some critical points which were the transition points of strain to tension or tension to strain when hot or cold liquids were consumed. The changes in oral temperature cause thermal fatigue and the material stability might be negatively affected. According to the thermal tension results in the present study, IPS Empress, Carrara press ceramic and Ceramco FAC all-ceramic materials exhibited different values while IPS Empress 2 material showed similar properties to that of enamel.

Parameters affecting retentive force of conus crowns.

The aim of this study was to determine the values of the retentive forces of the telescopic crowns. At the first step of the study, the samples having different heights and angles were compared in relation to retentive force. At the second step, the samples were subjected to removal procedures having a pre-determined speed, force and number. The obtained retention values were compared. Ninety dies were prepared in order to measure the retention of the conus crowns. The removal tests were performed with the insertion/separation device. The speed of the test device was 100 cm min(-1) providing the placement of the pieces with 5 kgf in 100, 200, 300, 500, 1000, 5000 and 10 000 cycles. The mean of the retention values of the changes of the angles were found to be statistically different (P < 0.01). According to the results of the variant analysis, the differences in the changes of the height were statistically significant (P < 0.01). The differences between the changes of the number of procedures of all groups were statistically significant (P < 0.01). The number of procedures, height and angle interactions were statistically insignificant (P = 0.758). According to the results of this study, the effect of the angle and height factors in terms of retention among the groups were not independent of each other. In equal angles, as the height increased, increased retention measurements were obtained. In more acute angles, the increase in retention was more obvious. It was also found that an accessory device was necessary to maintain retention capabilities after a long-term use.

Prognostic significance of tumor angiogenesis in epithelial ovarian cancer: in association with transforming growth factor beta and vascular endothelial growth factor.

We aimed to evaluate the prognostic significance of microvessel density (MVD), vascular endothelial growth factor (VEGF), and transforming growth factor beta (TGFbeta), as well as to find out the relationship between MVD, and VEGF and TGFbeta in epithelial ovarian cancer (EOC). Surgical specimens of 47 patients with stage I-IV primary EOC, who underwent extended surgical staging according to FIGO, were investigated. Five- micro m thick tissue sections were immunostained with antibody to factor VIII-related antigen, and MVD was assessed at three separate areas of x200 magnification. Expressions for VEGF and TGFbeta were evaluated by immunohistochemical staining using related monoclonal antibodies. Results were correlated with clinicopathologic factors and survival. We did not find any correlation between MVD and clinicopathologic factors, or patient survival. Similarly, there was no association between the degree of VEGF staining and survival or clinicopathologic factors, except preoperative ascites volume, which was higher in patients showing moderate and intense VEGF staining than those with weak VEGF staining (P = 0.052). The expression of TGFbeta was inversely correlated with preoperative CA-125 levels (P < 0.05). Furthermore, there was no correlation between MVD and the staining intensity of VEGF or TGFbeta. In conclusion, angiogenesis does not appear as a prognostic factor in EOC. We suggest that VEGF is an important mediator of ascites formation, and that TGFbeta, which is supposed to have tissue-specific actions in tumorigenesis, may have growth-inhibitory functions in EOC.

Multidisciplinary approach to restoring anterior maxillary partial edentulous area using an IPS Empress 2 fixed partial denture: a clinical report.

Esthetics is a major concern during restoration of anterior partial edentulous areas. All-ceramic fixed partial dentures may provide better esthetics and biocompatibility in the restoration of anterior teeth. This clinic report describes a multidisciplinary approach and treatment procedures with an IPS Empress 2 fixed partial denture to restore missing anterior teeth.