148 research outputs found
Effect of surface treatments on wear and surface properties of different CAD-CAM materials and their enamel antagonists.
STATEMENT OF PROBLEM
Which surface treatment provides optimal surface roughness, microhardness, and wear behavior for computer-aided design and computer-aided manufacturing (CAD-CAM) materials and their enamel antagonists is unclear.
PURPOSE
The purpose of this in vitro study was to evaluate the effect of surface treatment on the surface roughness, microhardness, and 2-body wear of different CAD-CAM materials and their enamel antagonists.
MATERIAL AND METHODS
Monolithic zirconia, polymer-infiltrated ceramic network, lithium disilicate, leucite-reinforced ceramic, zirconia-reinforced lithium silicate, and feldspathic ceramic specimens were sliced into 2-mm-thick rectangular plates and divided into polished or glazed subgroups (n=6). After surface roughness and microhardness measurements, the specimens were loaded at 49 N for 250 000 cycles and simultaneously thermocycled (5 °C and 55 °C). All specimens were scanned before and after the wear test by using a scanner. The volumetric loss and wear depth of the materials and the volumetric and height loss of the enamel were calculated, and scanning electron microscope images of the specimens were made. Multiple 2-way ANOVAs and Tukey honestly significant difference tests were used to assess the effect of material and surface treatment on surface roughness, microhardness, and wear behavior of materials and enamel (α=.05).
RESULTS
Material and surface treatment interactions affected the surface roughness (P<.001), microhardness (P<.001), volumetric loss of materials (P=.044), and height loss of enamel (P<.001).
CONCLUSIONS
Polishing resulted in higher surface roughness and microhardness than glazing. Volumetric loss depended on the material, which affected the height loss of the antagonists. Glazing and polishing had similar effects on the volumetric loss of materials and antagonists. No correlation was found between the wear of materials and the antagonists, nor between the surface roughness of materials and the volumetric loss of materials or antagonists
Anaesthesia and the Acute Phase Protein Response in Children Undergoing Circumcision
Concentrations of acute phase proteins (CRP: C-reactive protein, albumin) change during surgery. We investigated the acute phase response to circumcision and the effects of anaesthesia on this response. The children were divided into four groups; group 1 (intratracheal general anaesthesia, n = 40), group 2 (general anaesthesia with mask, n = 20), group 3 (ketamine, n = 20), group 4 (local anaesthesia, n = 35). Blood samples were obtained, 24 hours before circumcision, after premedication, and 24 hours after circumcision. CRP and albumin before circumcision were comparable for all groups. There was no increase in CRP, and albumin remained steady throughout the study. No difference was observed among the groups, and related to anaesthesia. No responsiveness may be explained with the size of injured tissue or anatomical and histological type of preputium
True knot of the umbilical cord in advanced weeks of pregnancy: a case report
True knot of the umbilical cord is a very rare condition. Usually a true knot is noticed after delivery and does not lead to problems. It is relatively less common than the other umbilical cord anomalies. Most authors agree that there is little that can be done to prevent fetal death in undiagnosed true knot. In our case, the patient gave birth to a healthy male baby weighing 2700 grams by normal vaginal delivery after an ultrasound was suggestive of intrauterine growth restriction (IUGR). The baby’s Apgar scores were 8 at one minute and 9 at five minutes. The umbilical cord measured 125 cm and contained two loose true knots. It was surprising that the baby could survive until term with these two knots and we hypothesize that this was the cause of the IUGR. Our case was interesting as neither neurologic sequela nor intrauterine death developed, despite two true umbilical cord knots
True knot of the umbilical cord in advanced weeks of pregnancy: a case report
True knot of the umbilical cord is a very rare condition. Usually a true knot is noticed after delivery and does not lead to problems. It is relatively less common than the other umbilical cord anomalies. Most authors agree that there is little that can be done to prevent fetal death in undiagnosed true knot. In our case, the patient gave birth to a healthy male baby weighing 2700 grams by normal vaginal delivery after an ultrasound was suggestive of intrauterine growth restriction (IUGR). The baby’s Apgar scores were 8 at one minute and 9 at five minutes. The umbilical cord measured 125 cm and contained two loose true knots. It was surprising that the baby could survive until term with these two knots and we hypothesize that this was the cause of the IUGR. Our case was interesting as neither neurologic sequela nor intrauterine death developed, despite two true umbilical cord knots
Impacted maxillary canines and their relationship with lateral incisor resorption: a cone beam computed tomography (CBCT) study
Comparison of Shear Bond Strengths of Ceramic Brackets Using Either Self-etching Primer or Conventional Method After Intracoronal Bleaching
Objective:To evaluate initial shear bond strengths (SBSs) of ceramic brackets using either a self-etching primer (SEP) or the conventional method (CM) after intracoronal bleaching with sodium perborate and distilled water.Materials and Method:Eighty human incisors were divided into 4 groups according to bleaching and bonding procedures: group 1, bleaching was not applied and brackets were bonded with SEP; group 2, bleaching was not applied and brackets were bonded with the CM; group 3, intracoronal bleaching with sodium perborate was applied for 3 weeks and brackets were bonded with SEP; group 4, intracoronal bleaching with sodium perborate was applied for 3 weeks and brackets were bonded with the CM. The SEP (Transbond Plus) was applied as recommended by the manufacturer. After SEP application, ceramic brackets were bonded with light cure adhesive (Transbond XT). For the CM, the teeth were etched with 37% phosphoric acid. After etching, a thin uniform coat of primer (Transbond XT Primer) was applied and ceramic brackets were bonded with light cure adhesive (Transbond XT). The SBSs were measured after water storage for 30 days, after 1000 cycles of thermocycling between 58C and 558C. Bond failure location was determined with the adhesive remnant index (ARI).Results:For the SEP method, there was no significant difference between the SBS values of the bleaching and nonbleaching groups. Furthermore, for the CM, the SBS value of the nonbleaching group was not significantly different from that of the bleaching group. The SBS values of the SEP method presented significant differences from the SBS values of the CM (p , 0.001). The SBS values of the SEP application decreased with and without bleaching. ARI scores did not show any significant difference between the groups (p = 0.174).Conclusion:Intracoronal bleaching with sodium perborate and distilled water did not affect the SBS values of ceramic brackets
Natural β-chitin-protein complex film obtained from waste razor shells for transdermal capsaicin carrier
In the literature, the produced β-chitin samples are in powder or flake forms but there is no natural β-chitin
based film. Also, the commercially available transdermal patches are produced from synthetic polymers. In this
regard,we produced natural β-chitin-protein complex (CPC) film fromthewaste shells of Ensis spp. The obtained
natural filmwas characterized by FTIR, TGA and SEM. Additionally, swelling, thickness, contact angle and antioxidant
tests were done to learn more about the films. After production and characterization of the film, capsaicin,
which is commonly used for pain reliefwas loaded into the film. The loading capacitywas recorded as 5.79%. The
kineticmodelswere studied in three different pH, then the resultswere fittedwith Higuchimodelwith high correlation
at pH 7.4. After considering all the obtained results, the capsaicin loaded CPC film may be an alternative
candidate for transdermal patch instead of the synthetic ones.info:eu-repo/semantics/publishedVersio
Rapid intraoperative tissue expansion with Foley catheter in a challenging cripple Hypospadias
The effect of the American Society of Anesthesiology classification scores on complications associated with percutaneous nephrolithotomy
Objectives: We aimed to evaluate the effect of American Society of Anesthesiology (ASA) classification scoring and age on complications and surgical outcomes during and after percutaneous nephrolithotomy (PCNL) operation.
Material and methods: The records of 263 patients, above the age of 18 years, that underwent PCNL surgery between October 2014 and May 2017 were evaluated retrospectively. The patients were divided into three groups based on their ASA risk scores (ASA 1, 2, 3) and into two groups based on their age (younger and older than 65 years). Postoperative complications were assessed according to the ASA groups and age and according to the Clavien classification system.
Results: The number of patients in the ASA 1, 2, and 3 groups were 97 (36.8%), 131 (49.8%) and 35 (13.3%), respectively. Four patients in ASA4 were not included in the study. There was no significant difference in ASA 1, 2, 3 groups in terms of changes in Hgb values, mean duration of operation, and mean hospital stay. When ASA1 was compared to ASA3 and ASA2 was compared to ASA3, there was no significant difference in the incidence of all complication rates. There were 159 (60.4%) patients in the young group and 104 (39.5%) patients in the elderly group. Postoperative PCNL complications of these 2 groups were compared according to Clavien classification system and no significant difference was found in incidence of complications.
Conclusions: We believe that PCNL operation can be performed effectively and safely in both ASA3 patients and patients above the age of 65 years
Skin to calyx distance is not a predictive factor for miniaturized percutaneous nephrolithotomy outcomes
- …