Ultrastructural Analysis of Urinary Stones by Microfocus Computed Tomography and Comparison with Chemical Analysis

Objective: To investigate the ultra-structure of urinary system stones using micro-focus computed tomography (MCT), which makes non-destructive analysis and to compare with wet chemical analysis. Methods: This study was carried out at the Ankara Train­ing and Research hospital. Renal stones, removed from 30 patients during percutaneous nephrolithotomy (PNL) surgery, were included in the study. The stones were blindly evaluated by the specialists with MCT and chemi­cal analysis. Results: The comparison of the stone components be­tween chemical analysis and MCT, showed that the rate of consistence was very low (p0.05). It was also seen that there was no significant relation between its 3D structure being heterogeneous or homogenous. Conclusion: The stone analysis with MCT is a time con­suming and costly method. This method is useful to un­derstand the mechanisms of stone formation and an im­portant guide to develop the future treatment modalities

Evaluation of Urinary Stones Ex Vivo With Micro-Computed Tomography: Preliminary Results of an Investigational Technique

Purpose: To evaluate the ultrastructural features of the urinary stonesremoved with endoscopic stone surgery, using micro computed tomography(micro-CT).Materials and Methods: Patients who had endoscopic surgery for renalor ureteral stones removal were included in this study. After surgery, thestones were classified into three groups and investigated with Skyscan 1174micro-CT. Group I underwent percutaneous nephrolithotomy (PNL) withultrasonic lithotripsy; group II had ureteroscopic stone surgery (USS) withpneumatic lithotripsy; and group III (the control group) had stone removalwith USS or PNL without lithotripsy. Stone homogeneity, voids, and theinternal structure of the stones were evaluated. Chi-square test was used toevaluate the difference statistically. P values less than .05 were consideredstatistically significant.Results: A total of 24 “calcium oxalate monohydrate” stones from 24patients were scanned with micro-CT. Stones treated with ultrasoniclithotripsy (group I) were more fragile, fragmented, and cracked than thosetreated with the pneumatic lithotripsy (group II; P = .01). Stones in groupII were more homogeneous and smooth than those in group I and resembled those of the control group (P = .02). Homogeneous, non-fragile stones andheterogeneous, fragile calculi were seen in all groups.Conclusion: The stone fragility could be confirmed by micro-CTinvestigation. Ultrasonic lithotripters increase the stone fragility, which isdemonstrated with increased heterogeneity by micro-CT

Comparison Of Micro-Computerized Tomography And Cone-Beam Computerized Tomography In The Detection Of Accessory Canals In Primary Molars

Purpose This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Materials and Methods Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. Results The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images. Conclusion Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth.PubMedScopu

Does Periosteal Graft Combined With Platelet-Rich Plasma Enhance the Healing of Bone Defect?

Vatansever, Alper/0000-0002-3632-1020WOS: 000434304300097PubMed: 29438203Introduction:This study investigated the effect of periosteal graft + platelet-rich plasma (PRP) combination on facial bone defect healing. Methods: Five-millimeter critical sized defects in zygomatic arches of 12 adult New Zealand rabbits were created. Rabbits were randomly divided into 3 groups: First group (control group): bone defects of left zygomatic arches of 6 rabbits were wrapped with a silicone tube. Second group (periosteal graft group): bone defects of left zygomatic arches of 6 rabbits were wrapped with periosteal graft. Third group (experimental group): bone defects of right zygomatic arches of 12 rabbits were wrapped with periosteal graft-PRP combination. New bone formation was evaluated at 8th and 16th weeks. One rabbit was sacrificed at 8th week. Remaining 11 rabbits were imaged with 3-dimensional computed tomography (CT) at 16th week; then, zygomatic arches were removed for micro-CT and histologic examinations. Results: Three-dimensional CT analysis at 16th week revealed no significant difference between groups regarding new bone formation (P = 0.232). Micro-CT analysis of new regenerated bone at 16th week displayed significant differences between groups 1 and 3 regarding mean bone volume (BV, mm(3)) (P = 0.028) and mean bone mineral density (BMD, mm(2)) (P = 0.001). There was no difference between groups 2 and 3 or between groups 1 and 2, regarding BV or BMD. Histological Bone Regeneration Scorings at 16th week displayed significant difference between groups (P = 0.015). Negative correlation between 3-dimensional CT and histologic results (r = 0.120); positive correlations between BV/BMD values in micro-CT and histologic results (r = 0.524 and r = 0.456) were found. Conclusions: By enhancing bone formation capacity of periosteal grafts, periosteal graft-PRP combination provided bone formation having more volume and density comparing with silicone tube application.Duzce University Scientific Research Foundation [2013.04.02.179]The authors acknowledge the support of Duzce University Scientific Research Foundation (Project No: 2013.04.02.179)

Investigation of the effects of semaphorin 3A on new bone formation in a rat calvarial defect model

Purpose: This study investigates the effects of semaphorin 3A on new bone formation in an experimental rat model

Epidermal growth factor enhances spinal fusion

Objective The aim of this study was to investigate the effects of human recombinant epidermal growth factor (EGF) on posterolateral lumbar fusion in a rat model. Methods 36 male Sprague Dawley rats underwent posterolateral fusion at L4-5 level. They were randomly assigned to 3 groups: 1- Sham control group where no local augmentation was made, 2- Local Hydoxyapatite β-tricalcium phosphate (HA/β-TCP) augmentation group and 3- Local HA/β-TCP + EGF augmentation group. Rats were euthanized at 8 weeks post-surgery. 6 rats from each group were selected for manual palpation examination, micro-computed tomography analysis and histologic analysis; and the rest was used for biomechanical analysis. Results Based on manual palpation, there was no fusion in the sham control group. Fusion rate was 33.3% in the HA/β-TCP group and 66.7% in the HA/β-TCP + EGF group (p = 0.085). Micro-CT results revealed that new bone formation was higher in the HA/β-TCP + EGF group (BV/TV: 40% vs. 65%) (p = 0.004). Histologically newly formed bone tissue was more pronounced in the EGF group and compacted and bridging bone spicules were observed. The median maximum bending moment values were 0.51 Nmm (0.42–0.59), 0.73 Nmm (0.49–0.88) and 0.91 Nmm (0.66–1.03) in the sham control, HA/β-TCP and HA/β-TCP + EGF groups, respectively (p = 0.013). The median stiffness values were 1.69 N/mm (1.12–2.18), 1.68 N/mm (1.13–2.74) and 3.10 N/mm (1.66–4.40) as in the previous order (p = 0.087). Conclusion This study demonstrates that EGF enhances posterolateral lumbar fusion in the rat model. EGF in combination with ceramic grafts increased the fusion rates. Our findings may provide insights to further studies, investigating EGF's clinical usage as an alternative fusion enhancer.PubMedWoSScopu