[Show abstract][Hide abstract] ABSTRACT: Background/purpose
The marginal fit of all-ceramic restorations is a very important criterion for their long-term success. The aim of this in vitro study was to compare the marginal adaptation of crowns fabricated with four different all-ceramic systems using an image analysis method.
Materials and methods
A standardized all-ceramic preparation was made on a stainless steel die. Eighty gypsum dies were duplicated from this die and randomly divided into four groups of 20 each. Cerec 3, In-Ceram, IPS Empress 2, and Celay crowns were fabricated on dies of each group following the manufacturers’ instructions. Marginal gaps of the crowns were evaluated without cementation on their own gypsum dies and then on the master die with a stereomicroscope and image analysis program. Two-way analysis of variance and Tukey's honest significant difference tests were used to evaluate the data (α = 0.01).
Mean gap dimensions and standard deviations at the marginal opening of the crowns evaluated on the gypsum dies were 21.5 ± 4 μm for Celay, 29.3 ± 5 μm for IPS Empress 2, 33 ± 4 μm for Cerec 3, and 74.6 ± 10 μm for In-Ceram crowns. Mean gap dimensions and standard deviations at the marginal opening of crowns evaluated on the master steel die were 27.8 ± 4 μm for Celay, 41.5 ± 7 μm for IPS Empress 2, 47.4 ± 5 μm for Cerec 3, and 94.9 ± 10 μm for In-Ceram crowns. Marginal opening values measured on the master die were higher than those of gypsum dies.
In-Ceram all-ceramic crowns showed the largest marginal gap, and Celay crowns showed the smallest marginal gap in both die groups. The marginal discrepancies found in this study were all within the clinically acceptable standard of 120 μm.
[Show abstract][Hide abstract] ABSTRACT: Introduction:
The aim of this study was to analyze the effects of screw design and force application on the stability of miniscrews, using RTT, SEM, and histomorphometric analyses.
Materials and methods:
Eighty cylindrical, self-drilling, and Ti6Al4V alloy miniscrews (1,6 × 6 mm) were used. Four mini-screws were inserted in fibulas of each rabbit, and 115 G of force was immediately applied. Four miniscrews were inserted in the other fibula, on which no force was applied. Eight weeks after insertion, osseointegration between miniscrew and the surrounding bone was evaluated by the histomorphometric analyses, SEM, and RTT. Kruskal-Wallis and the paired t-tests were used for statistical analysis.
Values obtained from Group I were significantly higher than those of the other loaded groups (P < .05). There were no differences in RTT scores among Groups II, III, and IV. Similar findings were also observed for unloaded mini-screws. There was no significant difference between Groups I and I(C), while the differences between loaded and unloaded controls for each miniscrew were statistically significant.
Immediate loading of miniscrews does not impair screw stability. Also, the diameter of miniscrew and more frequent thread pitches have a positive effect on stability; however, length of miniscrews does not have a significant effect on the stability.
The Scientific World Journal 07/2013; 2013(2):396091. DOI:10.1155/2013/396091 · 1.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Amelogenesis imperfecta (AI) is a group of hereditary disorders primarily characterized by developmental abnormalities in the quantity and/or quality of enamel. There are some reports suggesting an association between AI and generalized gingival enlargement. This paper describes the clinical findings and oral management of two siblings presenting both AI and hereditary gingival fibromatosis (HGF) like generalized gingival enlargements. The treatment of gingival enlargements by periodontal flap surgery was successful in the management of the physiologic gingival form for both patients in the 3-year follow-up period. Prosthetic treatment was also satisfactory for the older patient both aesthetically and functionally.
[Show abstract][Hide abstract] ABSTRACT: This study compared the effect of systemic and local administration of alendronate on distraction osteogenesis in rabbit mandibles. Thirty New Zealand white rabbits were allocated to 3 groups: 10 rabbits for systemic alendronate; 9 for local alendronate; and 11 as controls. After a 5 day latency period, distraction was performed at a rate of 0.8mm/day for 9 days via a custom-made distractor. Animals were killed at the end of the consolidation period of 28 days. The distracted mandibles were harvested and evaluated by plain radiography, computed tomography (CT), dual energy X-ray absorptiometry (DEXA), and histomorphometry. Histologically, comparing the systemic and local alendronate groups, there were no statistically significant differences in the bone healing parameters, but each group showed a statistically superior effect over the control group (p<0.05). Quantitative CT evaluation showed a significant difference mean in the density of the regeneration between experimental and control groups. There was a significant increase in mean bone mineral density in the experimental groups compared with the control group. Histologic, CT, and DEXA analysis demonstrated that using systemic and local alendronate may be effective in accelerating new bone formation in the distraction gap in rabbit mandibles.
International Journal of Oral and Maxillofacial Surgery 09/2011; 40(12):1395-400. DOI:10.1016/j.ijom.2011.08.004 · 1.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to determine whether intravenous immunoglobulin (IVIG) prevents cerebral vasospasm in rabbits with induced subarachnoid haemorrhage (SAH). The effect of IVIG on apoptosis in the endothelial cells of the basilar artery was also evaluated.
Eighteen New Zealand white rabbits were allocated randomly into three groups. SAH was induced by injecting autologous blood into the cisterna magna. Group 1, the control group, was subjected to sham surgery (no induction of SAH). Group 2 had SAH alone and Group 3 had SAH plus IVIG. Three days after treatment, the animals were sacrificed. The basilar artery tissues were analysed histologically and the malondialdehyde levels in the brain stem tissues were evaluated biochemically.
Differences in the histopathological luminal areas and full wall thicknesses in the SAH plus IVIG group and the SAH group were statically insignificant (p > 0.005). The malondialdehyde level was also found to be lower in the IVIG group than in the SAH group, although this difference was not significant (p > 0.005).
Although the IVIG treatment was revealed to have no vasodilator effect on the SAH-induced spastic basilar artery, it was shown to have a beneficial effect on the apoptosis of endothelial cells, probably via anti-inflammatory mechanisms.
[Show abstract][Hide abstract] ABSTRACT: Myxoid liposarcoma (MLS) is the most commonly encountered liposarcoma subgroup, accounting for about 50% of all cases. Metastatic MLS of the heart is extremely rare. Herein we describe for the first time metastasis of MLS to the left atrium and left upper pulmonary vein in a 54-year-old woman who was admitted with shortness of breath and cough persisting for 2 weeks. The patient reported that a total surgical excision of MLS of the left thigh followed by radiotherapy was performed 4 years ago. An emergency operation was performed due to rapidly progressive worsening of clinical condition and echocardiographic determination of left atrial mass protruding into the left ventricle and obstructing the mitral inflow throughout the diastole. The mass could not be totally excised because it was tightly adhered to the surrounding tissue. Postoperative magnetic resonance imaging (MRI) showed a 5 × 3 cm residual tumor deforming the posterior wall of the left atrium entirely and extending into the left upper pulmonary vein. Histopathological examination was consistent with MLS. In conclusion, considering probable cardiac metastasis in patients presenting with respiratory symptoms with medical history of soft tissue sarcomas would be life saving. The case is discussed, and a review of the literature in relation to the metastatic involvement of the heart by MLS is presented.
Heart Surgery Forum 08/2011; 14(4):E261-3. DOI:10.1532/HSF98.20111021 · 0.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study is to evaluate CD4(+), CD8(+), and CD45RO(+) T cells, and vascular endothelial growth factor (VEGF) expression in cyclosporin A (CsA)-induced rat overgrown gingival tissue during an 8-week period.
Sixty male Sprague-Dawley rats weighing 200 to 250 g were used in this study. Mandibular first molars were ligated with 3-0 silk suture. The rats received daily doses of 0.09% NaCl (control group) or 10 mg/kg body weight of CsA (test group) by intraperitoneal injections. Five rats from the control group and 10 rats from the test group were sacrificed at each experimental period (2, 4, 6, and 8 weeks after the beginning of CsA treatment). The specimens were examined immunohistochemically.
CD4(+), CD8(+), and CD45RO(+) T cells, and VEGF expression were more prevalent in the CsA-treated group than in the control group (P <0.05). VEGF was significantly correlated with CD4(+) T cells, CD4(+)/CD8(+) ratio, and CD45RO(+) cells (P <0.05).
Based on our findings, we conclude that VEGF, a major regulator of angiogenesis, and CD4(+), CD8(+), and CD45RO(+) memory T cells play a key role in CsA-induced gingival overgrowth.
Journal of Periodontology 06/2011; 83(2):248-55. DOI:10.1902/jop.2011.110034 · 2.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study aimed to examine the effects of melatonin supplementation on liver glycogen levels in rats with streptozotocin- induced diabetes and subjected to acute swimming exercise.
Eighty Sprague-Dawley type adult male rats were divided into eight groups: Group 1, general control; Group 2, melatonin-supplemented control; Group 3, melatonin-supplemented diabetes; Group 4, swimming control; Group 5, melatonin-supplemented swimming; Group 6, melatonin-supplemented diabetic swimming; Group 7, diabetic swimming; Group 8, diabetic control. Melatonin was supplemented at a dose of 3 mg/kg/day intraperitoneally for four weeks. Liver tissue samples were collected and evaluated using a Nikon Eclipse E400 light microscope. All images obtained from the light microscope were transferred to PC medium and evaluated using Clemex PE 3.5 image analysis software.
The lowest liver glycogen levels in the study were found in group 4. Liver glycogen levels in groups 3, 6, 7 and 8 (the diabetic groups) were higher than group 4, but lower than those in groups 1 and 2. The lowest liver glycogen levels were obtained in groups 1 and 2.
The study indicates that melatonin supplementation maintains the liver glycogen levels that decrease in acute swimming exercise, while induced diabetes prevents this maintenance effect in rats.
Endokrynologia Polska 05/2011; 62(3):252-6. · 0.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Diabetes is a metabolic disorder that affects much of the human population. As a secondary complication, diabetic neuropathy causes time-dependent damage to peripheral nerves. In this study, experimental diabetes was induced by streptozotocin (STZ; 50 mg/kg intraperitoneally) in rats. Diabetic animals were grouped into those with 2 or 4 weeks of diabetes, whereas a control group received only the STZ vehicle (0.1 M citrate). Sciatic nerves were dissected, and compound action potentials (CAPs) were recorded. Results deduced by conventional calculation carried less information when compared with conduction velocity distribution (CVD) obtained by a computer-based mathematical model. Using the conventional approach, statistically significant changes were first seen in the fourth week of diabetes, whereas results deduced by CVD measurement could be seen in the second week. Consequently, the CVD calculation provides more information for the early diagnosis of neuropathies compared with classical conduction velocity measurements.
[Show abstract][Hide abstract] ABSTRACT: Experimental Study.
The aim of this study was to investigate the neuroprotective effects of iloprost and piracetam on spinal cord ischemia/reperfusion (I/R) injury in the rabbit.
The Experimental Research Center of Selcuk University, Konya, Turkey.
A total of 24 rabbits were divided into four groups of six rabbits each, as follows: group 1 (n = 6) sham, laparotomy only; group 2 (n = 6) I/R; group 3 (n = 6) I/R+iloprost; and group 4 (n = 6) I/R+piracetam. I/R was established in groups 2, 3 and 4. Subsequently, they were followed up neurologically for 24 h until the rabbits were killed; biochemical and histopathological examinations of samples from the spinal cord were carried out.
Neurological examination results were significantly better in the iloprost and piracetam groups compared with the I/R group (P < 0.05). Neuroprotection was achieved with iloprost and piracetam by suppressing malondialdehyde (P < 0.05), increasing glutathione peroxidase activity (P < 0.05) and decreasing the xanthine oxidase level. In histopathological assessment, iloprost and piracetam groups were statistically different from the I/R group in terms of the number of apoptotic neurons in gray matter and white matter, as well as in terms of degenerated neurons and glial cells (P < 0.05). No statistical difference was determined between the four groups in the number of degenerated glial cells (P > 0.05).
This study has shown that iloprost and piracetam have neuroprotective effects in I/R injury both neurologically and histopathologically because of inhibition of lipid peroxidation.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to investigate the possible effect of acute regenerate molding (ARM) on bone healing in mandibular distraction osteogenesis (DO).
Nine white New Zealand rabbits underwent unilateral mandibular lengthening via DO. Three groups were created: The first underwent 15° ARM, the second group underwent 30° ARM after the distraction period, and the third group served as control without molding. After 1 month of consolidation, all of the animals were killed and histomorphometric evaluation was performed.
New bone formation was uneventful in all of the groups. In the ARM groups, the amounts of osteoblasts and newly formed bone areas were higher in compressed areas than in stretched ones (P < .05). The regenerates in the control group and stretched regenerate areas of the ARM groups were similar regarding new bone formation (P > .05).
Acute regenerate molding could be safely applied immediately after the distraction period to correct postdistraction deformities without compromising bone healing.
[Show abstract][Hide abstract] ABSTRACT: This study concerns the development of "NEO Image Analysis Software", a software package that can perform analyses on pathological images. The objective of the program is to minimize subjectivity of the pathologist in the diagnosis and treatment of diseases by standardizing the measurements. The following analyses have been performed on the images: area detection, angle detection, edge detection, blurring, sharpening, area counting, finding the ratio of areas with different colours, inversion, colour-to-gray scale conversion, colour mapping and drawing-based analysis (rectangular, circular, polygon and random).
Computers in Biology and Medicine 08/2010; 40(8):715-22. DOI:10.1016/j.compbiomed.2010.06.006 · 1.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although microsurgery has rapid expanded, problems related to microarterial anastomosis continue. Cigarette smoking is one of the major risks for anastomosis by increasing platelet adhesion, and its effects on endothelial cells. Aim of this article is to study the negative effects of cigarettes on microarterial anastomosis line, and to investigate the protective effects of recombinant human erythropoietin (rHuEPO).Ninety-six Sprague-Dawley male rats were divided into 3 groups: group 1 was the control. Rats in groups 2 and 3 were exposed to cigarette smoke starting 21 days prior to surgery for 3 times a day. In group 3, additional 150 IU/kg rHuEPO was given via subcutaneously every 48 hours after microvascular anastomosis, femoral arterial samples, and blood samples were taken for assessment at 1st, 3rd, 5th, and 7th day. Intimae/media ratios were calculated for morphologic analyses.On morphologic analysis of femoral arteries there were statistically significant differences for all 3 groups at 1st, 3rd, 5th, and 7th days (P < 0, 05). The group that made differences was group 2, according to one-way analysis of variance within 3 groups in all days.Smoking decreases endothelial cells healing and causes more thromboses. rHuEPO can prevent these negative effects of smoking.
Annals of plastic surgery 07/2010; 65(1):91-5. DOI:10.1097/SAP.0b013e3181b404fa · 1.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to investigate the ability of levosimendan to prevent cerebral vasospasm in a rabbit model of subarachnoid haemorrhage (SAH).
Eighteen New Zealand white rabbits were allocated into three groups randomly. SAH was induced by injecting autologous blood into the cisterna magna. (Group 1 = control:sham surgery group, Group 2 = SAH alone group, Group 3 = SAH plus levosimendan group). Histopathological examination was performed on day 3 as described. Intravenous levosimendan dose (initially 12 microg kg(-1) infusion, continuously for at least 10 minutes and then continued with a dose of 0.2 microg kg(-1) min(-1)) treatment was started after the induction of SAH. Three days later, the animals were sacrificed.
In pathological investigation; there was statistically significant difference in luminal area and muscular wall thickness of the basilar artery between all groups (p < 0.005). Malondialdehyde level was also found significantly low in the levosimendan group compared with the SAH group.
Intravenous levosimendan treatment was found effective by increasing the pathological luminal area and reducing muscular wall thickness measurements. This is the first study to show that intravenous administration of levosimendan is effective in preventing cerebral vasospasm induced by SAH in rabbits.
[Show abstract][Hide abstract] ABSTRACT: The formation of biofilm and bacterial accumulation on dental materials may lead to the development of gingival inflammation and secondary caries.
The purpose of this study was to examine the effect of different surface finishing and polishing methods on surface roughness and the adhesion of S. mutans bacteria to 2 new-generation indirect composite resins, 1 direct composite resin, and 1 ceramic material.
Forty specimens (10 x 10 x 2 mm) of each material, indirect composite resins (SR Adoro, Estenia), direct composite resin (Tetric), and a ceramic material (VITABLOCS Mark II), were fabricated. Specimens were divided into 4 groups (n=10) that were treated with 1 of the following 4 surface finishing techniques: diamond rotary cutting instrument, sandpaper discs (Sof-Lex), silicone-carbide rubber points (Shofu), or a felt wheel with diamond paste. Surface roughness was measured with a profilometer. Test specimens were covered with artificial saliva and mucin to produce pellicle. Bacterial suspension (10(9) CFU/ml) was then added to the pellicle-coated specimens, and bacterial adhesion was determined using a confocal laser microscope and image analyzing program. Data were analyzed with 2-way ANOVA, followed by Tukey HSD test, Pearson correlation, and regression analysis (alpha=.05).
The highest surface roughness values were recorded in SR Adoro and diamond rotary cutting instrument groups. The lowest vital S. mutans adhesion was seen in the ceramic group and in SR Adoro indirect composite resin (P<.05).
Bacterial adhesion to indirect composite resin materials differed from that to ceramic material after surface treatments. A positive correlation was observed between surface roughness and the vital S. mutans adhesion.
The Journal of prosthetic dentistry 04/2010; 103(4):221-7. DOI:10.1016/S0022-3913(10)60034-0 · 1.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study aimed to determine histopathologic changes in the pelviureteral junction in children with pelviureteral junction obstruction.
Seventeen pelviureteral junction specimens obtained from children were divided into two groups: pelviureteral junction obstruction (n = 7) and control (n = 10). Wall thickness of the pelviureteral junction, tunica muscularis of the pelviureteral junction, uroepithelium thickness of the pelviureteral junction, and collagen thickness of the pelviureteral junction were evaluated in resected pelviureteral junctions in children with pelviureteral junction obstruction.
The mean wall thickness of the pelviureteral junction, mean tunica muscularis of the pelviureteral junction, and uroepithelium thickness of the pelviureteral junction were not significantly higher than those in the control group. Collagen thickness values in the pelviureteral junction obstruction group were significantly higher than those in the control group.
Our data suggest that wall thickness (tunica muscularis and uroepithelium) was not significantly increased, but collagen thickness of the ureter was increased in the pelviureteral junctions of children with pelviureteral junction obstruction.