Micro-CT evaluation of the removal of root fillings using rotary and reciprocating systems supplemented by XP-Endo Finisher, the Self-Adjusting File, or Er,Cr:YSGG laser.

Objectives: This study aimed to compare the effectiveness of a single-file reciprocating system (WaveOne Gold, WOG) and a multi-file rotary system (ProTaper Universal Retreatment, PTUR) in removing canal filling from severely curved canals and to evaluate the possible adjunctive effects of XP-Endo Finisher (XPF), the Self-Adjusting File (SAF), and an erbium, chromium: yttrium, scandium, gallium garnet (Er,Cr:YSGG) laser using micro-computed tomography (µCT). Materials and Methods: Sixty-six curved mandibular molars were divided into 2 groups based on the retreatment technique and then into 3 based on the supplementary method. The residual filling volumes and root canals were evaluated with µCT before and after retreatment, and after the supplementary steps. The data were statistically analyzed with the t-test, Mann-Whitney U test, analysis of covariance, and factorial analysis of variance (p < 0.05). Results: PTUR and WOG showed no significant difference in removing filling materials (p > 0.05). The supplementary techniques were significantly more effective than reciprocating or rotary systems only (p < 0.01). The supplementary steps showed no significant differences in canal filling removal effectiveness (p > 0.05), but XPF showed less dentin reduction than the SAF and Er,Cr:YSGG laser (p < 0.01). Conclusions: The supplementary methods significantly decreased the volume of residual filling materials. XPF caused minimal changes in root canal volume and might be preferred for retreatment in curved root canals. Supplementary approaches after retreatment procedures may improve root canal cleanliness.

Modification and Validation of the Vaccine Hesitancy Scale for Turkish Adult Vaccination.

Background and Purpose: For public health, it is important to investigate vaccine hesitancy, determine populations reluctant for vaccines, and investigate barriers and facilitators for vaccination in these groups. This study aims to modify and validate the Vaccine Hesitancy Scale specific to adults in Turkish society. Methods: The study, which was designed as a methodological and survey type, was conducted using a Google questionnaire with 720 participants who met the inclusion criteria with a convenient sampling method. Results: After factor and reliability analysis, a 2-factor, 10-item scale with an acceptable and perfect range of fit index values emerged. It has been observed that individuals who are young, single, do not have children, have vaccine allergy, do not believe that the vaccine will protect the society, are adversely affected by the environment, and do not have COVID-19 and flu vaccine have a high level of hesitancy to vaccine. Conclusions: The Vaccine Hesitancy Scale is a valid and reliable tool to detect vaccine hesitation in adults in Turkish society.

Investigation of taurine and aqueous garlic extract diet supplementation effect on the healing of rat osteoporotic fractures.

BACKGROUND: We have evaluated the effects of taurine and aqueous garlic extract (AGE) as a dietary supplement on osteoporotic fracture (OPF) healing in the ovariectomized rat femur fracture model. METHODS: In this experimental animal study,twenty-four osteoporosis-remodeled female Wistar albino rats were randomly divided into 3 groups (n: 8) according to their supplemented diet; control, taurine, and AGE groups. Unilateral femur middiaphysis mini-open osteotomy was stabilized with Kirschner wires. Six weeks after osteotomy, the rats were sacrificed before the femurs were harvested and OPF healing was evaluated with biochemical, histologic, microcomputed-tomography, and scintigraphic methods. RESULTS: As an indicator of the antiosteoporotic effect, the calcium levels of the taurine group were significantly lower than the AGE and control groups in biochemical analyzes (p < 0.01). In histological studies, the new bone diameter and new bone volume values of the taurine group were significantly higher than the control group (p = 0.002 and p = 0.032, respectively), while higher trabecular-compact callus was observed in the taurine and AGE groups, respectively, compared to the control group. In morphological analyses, taurine and AGE groups had significantly higher bone volume/tissue volume, trabecular number, bone surface density, and lower trabecular separation than the control group (p < 0.05). The scintigraphic imaging showed a significant increase in osteoblastic activity of the taurine group compared to the control group (p = 0.005). DISCUSSION: Taurine and AGE have positive anabolic effects, respectively, on the healing of OPFs, demonstrated by biochemical, histological, morphological, and scintigraphic methods.

The combined use of carbon nanotubes with synthetic ceramics enhances posterolateral fusion: an experimental study in a rat spinal fusion model.

PURPOSE: The aim of the present study was to evaluate the effectiveness of carbon nanotubes (CNTs)/ HA-tricalcium phosphate (TCP) composite in a posterolateral spinal fusion model. METHODS: At first, CNTs and CNTs/HA-TCP composites were prepared. Twenty adult male Sprague Dawley rats were randomized into four groups with five rats in each group. Decortication was carried out in standard manner in all animals. Group 1 (only decortication), group 2 (CNTs), group 3 (HA-TCP) and group 4 (CNTs/HA-TCP) were formed. Eight weeks later, all animals were killed and obtained fusion segments were evaluated by manual palpation, histomorphometry and micro-computed tomography (mCT). RESULTS: In all evaluations, highest fusion values were obtained in Group 4. In mCT investigations, bone volume/ tissue volume (BV/TV) ratio was found to be significantly higher in composite group (group 4) only compared to ceramic group (group 3) (p < 0.001). Although in Group 2, in which only CNTs were used, the ratio was found to be statistically significantly higher than group 1(p < 0.001), the difference was not considered as significant in terms of fusion and in addition in group 2, CNTs were completely surrounded by fibrous tissue, i.e., no bone formation was observed. CONCLUSIONS: The CNTs/HA-TCP composite is a promising synthetic bone graft substitute for spinal fusion. Although CNTs are inadequate in producing spinal fusion when they are used alone, due to their high biocompatibility due to their high biocompatibility, and multiple effect on bone regeneration, they seem to increase fusion rates significantly when they are used in combination with ceramic-based synthetic grafts.

The illustrations and terminology of Hamse-i Sânizâde written by Sânizâde Ataullah Efendi: the stomach / Las ilustraciones y terminología de Hamse-i Sânizâde escrito por Sânizâde Ataullah Efendi: el estómago

SUMMARY: The book "Mirâtü'l-Ebdân fi Tesrîh-i Âzâü'l-Insân" written by Sânîzâde Mehmet Ataullah Efendi was the first illustrated anatomy book published in the Ottoman Empire. The aim of this study was to determine the similarities and differences between the terms and definitions of stomach anatomy used by Sânîzâde at that time and those used today. The stomach section of the "Mirâtü'l-Ebdân fi Tesrîh-i Âzâü'l-Insân" was examined and related plates were translated into the Turkish language. Anatomical terms and definitions of stomach anatomy in this book were compared to the stomach terminology used in "Terminologia Anatomica" which is the reference book for terminology today. The stomach section was explained under the title "El-Babu-Sâlis fi Tesrihi'l-Mi'de" (Illustrated Stomach Anatomy) in this book. Parts, margins, arteries, veins, nerves and layers of the stomach were explained with the terms and definitions of that period. Terminologia Anatomica has 33 anatomical terms related to the stomach, while 15 terms were identified in the book "Mirâtü'l-Ebdân fi Tesrîh-i Âzâü'l-Insân". Although more terms related to the stomach anatomy are used today, the fundamental information on stomach anatomy in Sânîzâde's book was compatible with much of the information used in modern anatomy books today.

El libro "Mirâtü'l-Ebdân fi Tesrîh-i Âzâü'l- Insân" escrito por Sânîzâde Mehmet Ataullah Efendi fue el primer libro de anatomía ilustrado y publicado en el Imperio Otomano. El objetivo de este estudio fue determinar las similitudes y diferen- cias entre los términos y definiciones de la anatomía del estómago utilizados por Sânîzâde en ese momento y los que se utilizan en la actualidad. Se examinó la sección del estómago del "Mirâtü'l-Ebdân fi Tesrîh-i Âzâü'l-Insân" y las placas relacionadas se tradujeron al idioma turco. Los términos anatómicos y las definiciones de la anatomía del estómago en este libro se compararon con la terminología del estómago utilizada en Terminologia Anatomica, el libro de referencia para la terminología utilizado actualmente. La sección del estómago se explicó bajo el título "El-Babu-Sâlis fi Tesrihi'l-Mi'de" (Anatomía del estómago ilustrada) en este libro. Fueron definidas las partes, márgenes, arterias, venas, nervios y capas del estómago con los términos y definiciones de esa época. Terminologia Anatomica tiene 33 términos anatómicos relacionados con el estómago, mientras que 15 términos fueron identificados en el libro "Mirâtü'l-Ebdân fi Tesrîh-i Âzâü'l-Insân". Aunque hoy en día se utilizan más términos relacionados con la anatomía del estómago, la información fundamental sobre la anatomía del estómago en el libro de Sânîzâde era compatible con gran parte de la información utilizada en los libros de anatomía modernos en la actualidad.

A preliminary evaluation of in vivo response to a filament-wound macroporous collagen midurethral sling in an ovine model.

Stress urinary incontinence (SUI) impacts ~1/3 of women over age 50. Negative publicity around PP meshes used in pelvic prolapse repair drives the need for identifying alternative biomaterials for SUI repair. Our study evaluated in vivo response to collagen sling implanted in an ovine model. Electrocompacted collagen threads were filament wound as slings and crosslinked in genipin. Collagen slings were implanted suburethrally mimicking the transvaginal tape technique. Main study groups were: Collagen sling (n = 3, 6 months) and PP sling (n = 3, 6 months). Collagen sling was also tested at 3-weeks (n = 1) to observe early-stage tissue response and 1-year (n = 2) to assess biomaterial longevity in a preliminary capacity. Collagen slings healed to a fibrous ligament texture at 6 months and maintained such texture to 1 year. Histological scoring indicated biocompatible responses to collagen slings with no adverse events. All study groups exhibited complete tissue ingrowth and interstitial de novo collagen deposition at all time points. Collagen threads induced orderly de novo collagen deposition that was aligned along long axes of threads. Tissue infiltrated collagen slings that were explanted at 6 and 12 months presented similar structural strength with native tissues such as vagina and fascia, and PP (Lynx) slings (p > .05). With the limitation of low number of animals per time point in hindsight, this preliminary study justifies evaluation of collagen slings in a larger sample size of animals, particularly to assess persistence of ligamentous tissue response over longer durations than 1-year.

Evaluation of the Efficiency of the Graft Material Combined with Ozonized Blood in Maxillary Sinus Lifting Applications in Rabbits.

Objectives: The aim of this study is to investigate the effect of the graft material combined with ozonized blood on bone healing in rabbit in maxillary sinus lifting applications histomorphometrically, immunohistochemically and microtomographically. Materials and Methods: Twenty-eight New Zealand rabbits were randomly divided into 2 groups as experimental (n = 14) and control (n = 14). In experimental group, 5 ml (milliliter) blood obtained from the ear vein of each rabbit was ozonized by 80 µl (µl)/ml concentration ozone-oxygen mixture. Graft material was combined with this ozonized blood. In control group, the graft was combined with saline solution at 0.9% concentration. A 5 mm (millimeter) in diameter window was created on right maxillary sinus window in each rabbit under general anesthesia by local anesthesia support. Sinus membrane was elevated and the space was augmented by 1 cc (cubic centimeter) graft material. One rabbit from the control group which was planned to sacrifice at the end of 8 weeks could not participate in the evaluation because of the extensive inflammation at the operation site. Newly formed bone area and bone density were measured using by image analysis program. Bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF) and collagen-1 (COL-1) analyses were carried out immunohistochemically. The amount of the newly generated bone and the amount of the total augmented space were calculated volumetrically by microtomography. Results: According to histomorphometrical analysis, although newly formed bone area has increased in both experimental and control group with time, statistically significant results were obtained when only O-8 (ozone-treated experimental group planned to be sacrificed after 8 weeks) and O-4 (ozone-treated experimental group planned to be sacrificed after 4 weeks) groups were compared (p = 0,037). The increase in new bone density was seen in both experimental and control groups with time and the results were statistically significant when O-8 group compared to O-4 and C-4 group (ozone-free control group planned to be sacrificed after 4 weeks) (p = 0,07 and p = 0,04, respectively) and C-8 (ozone-free control group planned to be sacrificed after 8 weeks) group compared to C-4 group (p = 0,023). According to immunohistochemical analysis, the intensity and the severity of field staining with anti-BMP-2 have increased in experimental group whereas it has decreased in control group but despite that there was no statistically significance among all groups compared to each other. The number of new vessels stained with anti-VEGF has increased in both experimental and control group with time and multiple comparison results were statistically significant when O-8 group compared with O-4 and C-4 (p = 0,000, p = 0,000, respectively), O-4 group compared with C-8 (p = 0,000) and C-8 group compared with C-4 (p = 0,000). Although the intensity and the severity of field staining with anti-COL-1 have increased in both experimental and control group with time, there was no statistically significance among all groups compared to each other. According to microtomographical analysis, the percentage of the volume of the newly generated bone in the total augmented space volume has decreased with time in both experimental and control groups. Conclusions: Considering the results of this study, the graft material combined with the ozonized blood increased the density of the newly generated bone and the number of new vessels in maxillary sinus lifting applications in rabbits. Clinical Relevance: We suggest further studies should be done combining the graft with ozone by different methods, dosages and exposure times.

The effect of favipiravir versus hydroxychloroquine on clinical and laboratory findings in COVID-19 in healthcare workers.

OBJECTIVES: Comparative data on hydroxychloroquine and favipiravir, commonly used agents in the treatment of Coronavirus Disease-2019 (COVID-19), are still limited. In this study, it was aimed to compare treatment outcomes in healthcare workers with COVID-19 who were prospectively followed by the occupational health and safety unit. METHODS: A total of 237 healthcare-workers, diagnosed as mild or moderate COVID-19 between March 11, 2020 and January 1, 2021, were given hydroxychloroquine (n = 114) or favipiravir (n = 123). Clinical and laboratory findings were evaluated. RESULTS: The mean age of the patients was 33.4±11.5 years. The mean time to negative PCR was found to be significantly shorter in patients receiving favipiravir compared to the hydroxychloroquine group (10.9 vs. 13.9 days; p < 0.001). The rate of hospitalization in the hydroxychloroquine group was significantly higher than favipiravir group (15.8% vs. 3.3%). In terms of side effects; the frequency of diarrhea in patients receiving hydroxychloroquine was significantly higher than that in the favipiravir group (31.6% vs. 6.5%; p < 0.001). CONCLUSIONS: Favipiravir and hydroxychloroquine were similar in terms of improvement of clinical symptoms of healthcare workers with mild or moderate COVID-19 infection, but favipiravir was significantly more effective in reducing viral load and hospitalization rates. Furthermore, favipiravir caused significantly less side-effects than hydroxychloroquine.

The effect of favipiravir versus hydroxychloroquine on clinical and laboratory findings in COVID-19 in healthcare workers

Abstract Objectives Comparative data on hydroxychloroquine and favipiravir, commonly used agents in the treatment of Coronavirus Disease-2019 (COVID-19), are still limited. In this study, it was aimed to compare treatment outcomes in healthcare workers with COVID-19 who were prospectively followed by the occupational health and safety unit. Methods A total of 237 healthcare-workers, diagnosed as mild or moderate COVID-19 between March 11, 2020 and January 1, 2021, were given hydroxychloroquine (n = 114) or favipiravir (n = 123). Clinical and laboratory findings were evaluated. Results The mean age of the patients was 33.4±11.5 years. The mean time to negative PCR was found to be significantly shorter in patients receiving favipiravir compared to the hydroxychloroquine group (10.9 vs. 13.9 days; p < 0.001). The rate of hospitalization in the hydroxychloroquine group was significantly higher than favipiravir group (15.8% vs. 3.3%). In terms of side effects; the frequency of diarrhea in patients receiving hydroxychloroquine was significantly higher than that in the favipiravir group (31.6% vs. 6.5%; p < 0.001). Conclusions Favipiravir and hydroxychloroquine were similar in terms of improvement of clinical symptoms of healthcare workers with mild or moderate COVID-19 infection, but favipiravir was significantly more effective in reducing viral load and hospitalization rates. Furthermore, favipiravir caused significantly less side-effects than hydroxychloroquine.

Analysis of the nano and microstructures of the cervical cementum and saliva in periodontitis: A pilot study.

OBJECTIVES: During the progression of periodontitis, the structures of the cementum and saliva are altered due to pathological changes in the environment. This study aimed to analyze the nanostructures of the cervical cementum and saliva in patients with periodontitis. METHODS: Patients with periodontitis (n = 10) and periodontally healthy controls (n = 8) were included. Single-rooted teeth with indications for extraction were obtained from individuals. The cervical-thirds of the roots were sectioned transversely to obtain 1 mm thick sections. Unstimulated whole saliva samples were collected from each individual. The nanostructures of the cementum and saliva were analyzed using small and wide-angle X-ray scattering methods. RESULTS: The mean radius and distance values of the cementum nanoparticles in the periodontitis and control groups were 368 Å and 1152 Å, and 377 Å and 1186 Å, respectively. The mean radius and distance values of the saliva nanoparticles in the periodontitis and control groups were 425 Å and 1359 Å, and 468 Å and 1452 Å, respectively. More wide-angle X-ray scattering profile peaks were observed in the cementum of the controls. Similarities were observed between the 3D profiles of the cementum and the saliva nanoparticles. CONCLUSIONS: According to the results of the present study, (i) the cementum and saliva nanoparticles were of similar size in periodontitis and healthy controls, (ii) the cementum was more crystalline according to the (002) crystallographic plane in controls, and (iii) the similarities in the 3D-profile of the cementum and saliva nanoparticles suggest some interactions between them in the sulcus/periodontal pocket at the nanolevel.

Evaluation of the effects of locally applied rosuvastatin on bone formation in a three-dimensional reconstruction rabbit xenograft model

Background/aim: Guided bone regeneration (GBR) is commonly performed to repair bone defects, and rigid occlusive titanium barriers play a vital role in bone formation in regions with no prior bone tissue. The statin, rosuvastatin (RSV), strongly affects bone apposition when applied locally. Here, we aimed to evaluate the anabolic effects of locally applied RSV with a xenograft placed on rabbit calvaria. Materials and methods: Two rigid occlusive titanium caps were used in 16 rabbits after decorticating the calvarial bone. In the control group, the area under the cap was filled with a xenograft, while in the RSV group, a xenograft in combination with RSV (1 mg) was used. In both groups, at 6 and 12 weeks, new bone, residual graft, soft tissue areas, and histological and radiological bone volume were evaluated. Results: At 12 weeks, histologically, the RSV group exhibited superior new bone proportion values, and radiologically, new bone and total bone volume in the RSV group were significantly higher than in the control group (p < 0.05); there were no significant differences at 6 weeks (p > 0.05). Conclusion: According to our results, RSV applied locally under a titanium barrier on an area to be repaired with bone grafts increases new bone and total bone volume.

Evaluation of an electrochemically aligned collagen yarn for textile scaffold fabrication.

Collagen is the major component of the extracellular matrix in human tissues and widely used in the fabrication of tissue engineered scaffolds for medical applications. However, these forms of collagen gels and films have limitations due to their inferior strength and mechanical performance and their relatively fast rate of degradation. A new form of continuous collagen yarn has recently been developed for potential usage in fabricating textile tissue engineering scaffolds. In this study, we prepared the continuous electrochemical aligned collagen yarns from acid-soluble collagen that was extracted from rat tail tendons (RTTs) using 0.25 M acetic acid. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy confirmed that the major component of the extracted collagen contained alpha 1 and alpha 2 chains and the triple helix structure of Type 1 collagen. The collagen solution was processed to monofilament yarns in continuous lengths by using a rotating electrode electrochemical compaction device. Exposing the non-crosslinked collagen yarns and the collagen yarns crosslinked with 1-ethyl-3-(-3-dimethyl-aminopropyl) carbodiimide hydrochloride to normal physiological hydrolytic degradation conditions showed that both yarns were able to maintain their tensile strength during the first 6 weeks of the study. Cardiosphere-derived cells showed significantly enhanced attachment and proliferation on the collagen yarns compared to synthetic polylactic acid filaments. Moreover, the cells were fully spread and covered the surface of the collagen yarns, which confirmed the superiority of collagen in terms of promoting cellular adhesion. The results of this work indicated that the aligned RTT collagen yarns are favorable for fabricating biotextile scaffolds and are encouraging for further studies of various textile structure for different tissue engineering applications.

A hybrid vascular graft harnessing the superior mechanical properties of synthetic fibers and the biological performance of collagen filaments.

Tissue-engineered small caliber vascular grafts have attracted much research attention as a viable alternative to traditional vascular grafts with their biocompatibility and potential to achieve complete healing. However, the major challenge is to fabricate a scaffold with both satisfactory mechanical properties and fast endothelialization. In this study, a hybrid tubular vascular tissue engineered scaffold has been circular-knitted using novel electrochemically aligned collagen (ELAC) filaments plied together with traditional poly(lactic acid) (PLA) yarn. The collagen component was able to promote the recruitment and proliferation of endothelial cells by increasing the initial cell adhesion 10-fold and the eventual cell population 3.2 times higher than the PLA scaffold alone. At the same time, the PLA yarn was able to provide sufficient mechanical strength and structural stability, as well as facilitate scaffold fabrication on high speed textile production equipment. The tubular hybrid scaffold exhibited excellent bursting strength (1.89 ± 0.43 MPa) and suture retention strength (10.86 ± 0.49 N), and had comparable compliance (3.98 ± 1.94%/100 mmHg) to that of the coronary artery (3.8 ± 0.3%/100 mmHg) under normotensive pressure. With its excellent mechanical and biological performance, this prototype hybrid scaffold is a promising candidate for the construction of a clinically successful and easily translatable tissue-engineered small caliber vascular graft.

Filling quality of several obturation techniques in the presence of apically separated instruments: A Micro-CT study.

Separated root canal instruments may affect the quality of root canal obturation and hence the survival of endodontically treated teeth. Obturation techniques may influence filling-quality. The aim was to evaluate the obturation quality of teeth filled with different obturation techniques in the presence of apically separated instruments using micro-computed tomography (µ-CT). Notched ProTaper F2 rotary-files were separated in the apical third of 36-human mandibular incisors with single root/canal and mature apex. Samples were filled by an endodontist according to one of the following obturation techniques (n = 12): cold lateral-compaction (CLC), single-cone (SC) and thermoplastic injection (TI). Samples were scanned by the Skyscan 1,274® µ-CT device after 1-week at 37°C in 100% humidity. Images of the sections were evaluated with CTan software in terms of total-volume and volume percentage of the filling materials and voids between coronal end of the separated instrument and gutta-percha/sealer filled void-free sections. Data was analyzed using Kruskal-Wallis and Mann Whitney-U tests with a significance level of 5%. Kruskal-Wallis revealed differences among groups (p < 0.05).Pairwise comparisons revealed that less volume of voids were measured in SC (0.02 ± 0.03 mm3 ) compared to CLC (0.15 ± 0.16 mm3 ) and TI (0.18 ± 0.24 mm3 ) (p < 0.05); while TI was statistically similar with CLC (p > 0.05). Percentages of volumes of voids and filling materials were as follows for SC, CLC and TI, respectively: 8.88 ± 18.52% and 24.45 ± 38.40%, 46.92 ± 33.53% and 53.07 ± 33.53%, 40.54 ± 33.85% and 42.79 ± 34.45%. The obturation technique may have a significant impact on the volume of voids in the presence of a separated file. No obturation technique produced a void-free root canal filling.

Intramedullary implants coated with cubic boron nitride enhance bone fracture healing in a rat model.

BACKGROUND: Boron nitride is a biocompatible and an osteo-inductive material for orthopedic applications. The aim of this study was to evaluate the effects of two different allotrope boron nitride coated implants, cubic boron nitride and hexagonal boron nitride, on fracture healing. METHODS: In this experimental study, a total of 24 rats were divided into three groups. Group A was the control group with Kirschner wire without coating, while the wires were coated dominantly by cubic boron nitride in Group B and hexagonal boron nitride in Group C. Then a mid-third femoral fracture was created. The fracture healing was examined in terms of new bone formation with micro-CT analysis and histopathological examination, quantitative measurement of bone turnover metabolites and scintigraphic examination of osteoblastic activity on 28th day post fracture. RESULTS: Micro-CT measurement results revealed a statistically significant increase in bone volume/tissue volume ratio and bone surface values in group B compared to group A. Cortex diameter and osteoblast counts were statistically higher in group B compared to group A. Inflammatory response was increased in group C compared to groups A and B. Biochemical test results showed significantly increased alkaline phosphatase levels and decreased osteocalcin levels in group B compared to group A. The increase in serum phosphorus and decrease in serum calcium levels was statistically significant in group C compared to Group A. CONCLUSION: Both types of boron nitride coating had superior fracture healing features compared to control group. Therefore, c-BN coating can accelerate the fracture healing and could lead to shorten of union time.

Evaluation of the Amount of Root Canal Dentin Removed and Apical Transportation Occurrence after Instrumentation with ProTaper Next, OneShape, and EdgeFile Rotary Systems.

INTRODUCTION: The aim of this study was to evaluate the amount of root canal dentin removed and apical transportation occurrence after instrumentation of mesiobuccal canals of maxillary molars with ProTaper Next (PTN [Dentsply Maillefer, Ballaigues, Switzerland]), OneShape (OS [MicroMega, Besançon, France]), and EdgeFile (EF [Edge Endo, Albuquerque, NM]) rotary systems. METHODS: Twenty-seven mesiobuccal canals of maxillary molars were used. Canals were randomly divided into 3 groups for canal preparation: PTN, EF X3, or OS (n = 9 for each group). Micro-computed tomographic imaging was used to measure apical transportation (mm) and the volume of dentin removed (mm3). The amount of dentin removed was measured for the coronal portion and for the whole canal length. Superposition of pre- and postoperative cross-sectional apical slices were used to measure apical transportation at 1 mm from the apex; the differences were evaluated using the Kruskal-Wallis test and Wilcoxon analysis. The Spearman correlation coefficient was used to display the relationship between variables for each group. The significance level was set at P < .05. RESULTS: The percentages of the amount of dentin removed on the coronal portion and the amount removed for the whole canal length were statistically similar between groups (P > .05). The average amount of apical transportation for the PTN, OS, and EF X3 were 0.197, 0.263, and 0.218 mm, respectively. Statistically, there were no significant differences between the 3 rotary instruments for apical transportation. CONCLUSIONS: The amount of dentin removed for the coronal third portion and the whole canal length was similar for the PTN, OS, and EF X3 rotary instruments. Although there were differences in the sizes of apical enlargement, no apical transportation was observed in any of the instrumentation systems.

Locally administrated single-dose teriparatide affects critical-size rabbit calvarial defects: A histological, histomorphometric and micro-CT study.

OBJECTIVE: The aim of this study was to evaluate the effect of teriparatide (PTH 1-34, rhPTH) on a rabbit defect model with local xenogen grafts histomorphometrically and radiologically. METHODS: For this purpose, two 10 mm diameter critical-size defects were created in the calvaria of 16 rabbits. In the control group, the defect area was filled with a xenogen graft, while in the teriparatide group (PTH 1-34), a xenogen graft combination with 20 mcg teriparatide was used. For both 4 - week and 8 - week study groups, new bone, residual graft, and soft tissue areas were evaluated as well as bone volume histomorphometrically and radiologically. RESULTS: Histomorphometrically, there was a significant difference in new bone area values at the 8th week (p < 0.05), but there was no significant difference between the 4 - week values (p > 0.05). There was no statistically significant difference between the groups at both 4 and 8 weeks (p > 0.05). In the radiologically measured total bone volume values, PTH1-34 group values were found to be significantly higher for both 4 - and 8 - weeks values compared to the control groups (p < 0.05). CONCLUSION: In this study, rhPTH, which is used locally in defect areas to be repaired with bone grafts, increases both new bone volume and total bone volume.

Engineering small-caliber vascular grafts from collagen filaments and nanofibers with comparable mechanical properties to native vessels.

At the present time, there is no successful synthetic, off-the-shelf small-caliber vascular graft (<6 mm) for the repair or bypass of the coronary or carotid arteries. This stimulates on-going investigations to fabricate an artificial vascular graft that has both sufficient mechanical properties as well as superior biological performance. Collagen has long been considered as a viable material to encourage cell recruitment, tissue regeneration, and revascularization, but its use has been limited by its inferior mechanical properties. In this study, novel electrochemically aligned collagen filaments were used to engineer a bilayer small-caliber vascular graft, by circular knitting the collagen filaments and electrospinning collagen nanofibers. The collagen prototype grafts showed significantly greater bursting strength under dry and hydrated conditions to that of autografts such as the human internal mammary artery and the saphenous vein (SV). The suture retention strength was sufficient under dry condition, but that under hydrated condition needs to be further improved. The radial dynamic compliance of the collagen grafts was similar to that of the human SV. During in vitro cell culture assays with human umbilical vein endothelial cells, the prototype collagen grafts also encouraged cell adhesion and promoted cell proliferation compared to the synthetic poly(lactic acid) grafts. In conclusion, this study demonstrated the feasibility of the use of novel collagen filaments for fabricating small caliber tissue-engineered vascular grafts that provide both sufficient mechanical properties and superior biological performance.

Microcomputed Assessment of Transportation, Centering Ratio, Canal Area, and Volume Increase after Single-file Rotary and Reciprocating Glide Path Instrumentation in Curved Root Canals: A Laboratory Study.

INTRODUCTION: The aim of this study was to compare the transportation and centering abilities of the ProGlider (PG; Dentsply-Sirona, Ballaigues, Switzerland), WaveOne Gold Glider (WOGG; Dentsply-Sirona), and R-Pilot (RP; VDW, Munich, Germany) file systems and the changes in the structure model index (SMI), surface area, and root canal volume (after creating the glide path in the mandibular first molar teeth's mesial canals with moderate curvature) using the micro-computed tomographic (micro-CT) method. METHODS: In the present study, 24 mandibular first molar teeth with 2 separate mesial canals and moderate (10°-20°) curvature were used. After scanning with micro-CT imaging before the procedure, the teeth were divided into 3 groups, PG, WOGG, and RP (n = 10/each group), followed by the glide path procedure. After the root canal preparation, changes in the root canals regarding the volume, surface area, SMI, transportation made by the files, and the change of their centering ability in the apical, middle, and coronal third were analyzed by micro-CT imaging. The data were statistically evaluated using 1-way analysis of variance and the Kruskal-Wallis test with a significance level set at 5% (P < .05). RESULTS: The WOGG and RP file systems showed better centering abilities at all thirds compared with the PG file system (P < .05). No significant difference was found in the apical third between the groups in terms of canal transportation degree (P > .05). However, in the WOGG and RP groups, less transportation was observed in the middle and coronal thirds compared with the PG group (P < .05). When the SMI changed, after the root canal preparation was compared, no significant differences were found between the groups (P > .05). Nevertheless, the changes in volume and surface area of the root canal in the WOGG and RP groups were significantly lower than in the PG group (P < .05). CONCLUSIONS: The WOGG and RP file systems caused similar levels of change in the root canal systems based on all parameters. Moreover, it was determined that the PG file system caused a significantly higher volume and surface area increase than the WOGG and RP file systems.

Stem cells combined 3D electrospun nanofibrous and macrochannelled matrices: a preliminary approach in repair of rat cranial bones.

Repair of cranial bone defects is an important problem in the clinical area. The use of scaffolds combined with stem cells has become a focus in the reconstruction of critical-sized bone defects. Electrospinning became a very attracting method in the preparation of tissue engineering scaffolds in the last decade, due to the unique nanofibrous structure of the electrospun matrices. However, they have a limitation for three dimensional (3D) applications, due to their two-dimensional structure and pore size which is smaller than a cellular diameter which cannot allow cell migration within the structure. In this study, electrospun poly(ε-caprolactone) (PCL) membranes were spirally wounded to prepare 3D matrices composed of nanofibers and macrochannels. Mesenchymal stromal/stem cells were injected inside the scaffolds after the constructs were implanted in the cranial bone defects in rats. New bone formation, vascularisation and intramembranous ossification of the critical size calvarial defect were accelerated by using mesenchymal stem cells combined 3D spiral-wounded electrospun matrices.