Browsing by Author "Skagers, Andrejs"

Now showing 1 - 11 of 11
  • No Thumbnail Available
    Item
    Bone Loss around Dental Implants 5 Years after Implantation of Biphasic Calcium Phosphate (HAp/βTCP) Granules
    (2018) Klimecs, Vadims; Grishulonoks, Alexanders; Salma, Ilze; Neimane, Laura; Locs, Janis; Šauriņa, Eva; Skagers, Andrejs; Department of Doctoral Studies; Department of Oral and Maxillofacial Surgery and Oral Medicine; Rīga Stradiņš University; Statistics Unit
    Biphasic calcium phosphate ceramic granules (0.5-1.0 mm) with a hydroxyapatite and β-tricalcium phosphate ratio of 90/10 were used. Biphasic calcium phosphate ceramic granules produced in the Riga Technical University, Riga Rudolph Cimdins Biomaterials Innovation and Development Centre, were used for filling the bone loss on 18 patients with peri-implantitis. After 5 years at the minimum, clinical and 3D cone-beam computed tomography control was done. Clinical situation confirmed good stability of implants without any signs of inflammation around. Radiodensity of the previous gap and alveolar bone horizontally from middle point of dental implants showed similar radiodensity as in normal alveolar bone.
  • No Thumbnail Available
    Item
    Calcium Phosphate Bioceramic Material Local Influence on the Bone Biomechanical Properties at Rabbits with Experimental Osteoporosis
    (2018) Ananjevs, Vladislavs; Ananjeva, Aleksandra; Vētra, Jānis; Skagers, Andrejs; Salma, Ilze; Ločs, Jānis; Kasyanov, Vladimir; Department of Oral and Maxillofacial Surgery and Oral Medicine; Institute of Anatomy and Anthropology; Biomehānikas zinātniskā laboratorija
    Biomechanical characteristicsof the rabbit cartilagecomponentfrom the femurwereinvestigated.The controlosteoporosishad beenactivatedby ovariectomy alongside theinjections of methylprednisolone. During the experiment defects in the femur’sgreater trochanter zonewas created andafterwardsfilled withthefragmentsof a hydroxyapatite as well astricalcium phosphate(HAP/TCP 70/30) or HAP/TCP 70/30mixedwith five percentstrontium. Threemonths lateranimals were euthanazed, squared samples werecut out from the femur’sbody andlatertested on a bend. The results ofthe research revealedthat the femurs becomemorestringentafter filling offdefects in the greater trochanter zonewith HAP/TCP 70/30or HAP/TCP 70/30mixed with fivepercentstrontium. The ultimate painfor the cartilagecomponentin the controlgroupswas less, than in thetest group.The flexure modulus of flexibilityof a cartilagecomponentin the test groupwas statistically reliable less, than the value of the flexure modulus of flexibilityof the cartilagecomponentin the controlgroups. Therefore, local usage ofcalcium –phosphatic bioceramic componentoverthe greater trochanter partincreasesbiomechanical characteristicsof the cartilagecomponentin the femurof animals.
  • No Thumbnail Available
    Item
    Cone beam computed tomography evaluation of maxillary sinus before and after sinus floor elevation
    (2019-08-01) Neimane, Laura; Zamure, Liene; Klimecs, Vadims; Grišuļonoks, Aleksandrs; Skagers, Andrejs; Ivanovs, Andrejs; Rīga Stradiņš University; Statistics Unit; Institute of Public Health
    Sinus lift surgery elevation is a procedure that requires radiological maxillary sinus evaluation and procedure planning. The condition of the maxillary sinus before and after sinus lift surgery was assessed. Sixty-five sinuses of 49 patients were included in the study. Preoperative and postoperative cone beam computed tomography (CBCT) scans were performed. The sinuses were analysed radiologically for pathological changes: mucosal thickening, ostia obstruction and accessory opening. The presence of concha bullosa in nasal cavity and septa in the maxillary sinus were recorded. The sinus volume also was measured before and after surgery. Thickened mucosa was found more often in postoperative scans than in preoperative scans (63.1% and 67.7%, respectively). Concha bullosa was found in 30 preoperative scans and in 33 postoperative scans. A correlation between mucosal thickening and ostia obstruction was found. The mean sinus volume decreased after surgery and the changes were statistically significant. In conclusion, changes of the maxillarysinus and nasal cavity can be detected with CBCT. Sinus lift surgery does not excacerebate the existing conditions of the maxillary sinus; however, there is a tendency for pathological features to increase after surgery. Sinus lift surgery is a safe surgery with regard to the maxillary sinus if performed with care.
  • No Thumbnail Available
    Item
    Early morphofunctional response of contact tissue after intraosal implantation in rabbit jaw of pure synthetic hydroxyapatite (HAp) bioceramic materials and HAp saturated with lidocaine
    (2009) Salma, Ilze; Pilmane, Mara; Skagers, Andrejs; Vetra, Janis; Salms, Girts; Berzina-Cimdina, Liga; Serzane, Rita; Department of Oral and Maxillofacial Surgery and Oral Medicine; Institute of Anatomy and Anthropology
    PURPOSE: The aim of this study was to evaluate early morphofunctional response of contact tissue to pure and saturated with lidocaine porous synthetic HAp ceramic implants inserted in holes of rabbit upper jaw. MATERIALS AND METHODS: Pure and saturated with lidocaine cylinders of porous HAp ceramics produced at Biomaterials R&D Laboratory of Riga Technical University were inserted into edentulous part of the upper jaw of 12 New Zealand male rabbits. After two weeks, blocks of soft tissue and bone were taken out. The sections done with EXACT Grunding system and from paraffin blocks were stained with haematoxylin/eosin and by use of biotin-streptavidin immunohistochemistry for transforming growth factor beta1 (TGFbeta1), fibroblast growth factor receptor 1 (FGFR1), interleukin 10 (IL10). Apoptosis was detected by TUNEL method. RESULTS: TGFbeta1 was equally expressed in the bone around HAp implants saturated with lidocaine and without lidocaine, while control sections did not show any expression of TGFbeta. In contacting bone tissue to pure HAp and HAp saturated with lidocaine as well in controls rich expression of FGFR1 was observed. In soft tissue of experimental samples also rich expression of FGFR1 was observed, although it was weak in control samples. IL10 had rich expression in all samples. The mean number of apoptotic cells was higher in samples with pure HAp, slightly decreased in samples HAp with lidocaine and significantly lower in controls. CONCLUSIONS: The expression of TGF beta1 confirms osteoinductive activity of HAp. Contact soft tissue to HAp showed rich FGFR1 expression, and weak in controls suggesting higher plasticity of connective tissue to implants in comparison with supportive tissue. Slightly lower apoptosis in samples of HAp with lidocaine gives evidence of indistinct influence of saturated with lidocaine HAp implants on development of programmed cell death.
  • No Thumbnail Available
    Item
    Experimental Study of Neuropeptide Containing Nerve Fibres
    (1997) Paegle, D; Skagers, Andrejs; Pilmane, Māra; Department of Morphology
  • No Thumbnail Available
    Item
    General influence of biphasic calcium phosphate on osteoporotic bone density
    (2019-05-01) Ananjevs, Vladislavs; Ananjeva, Aleksandra; Vetra, Janis; Skagers, Andrejs; Salma, Ilze; Neimane, Laura; Kasyanov, Vladimir; Department of Oral and Maxillofacial Surgery and Oral Medicine; Institute of Anatomy and Anthropology; Biomehānikas zinātniskā laboratorija
    Bone density of the femur body of rabbit was determined in vivo. Experimental osteoporosis was induced by ovariectomy and subsequent injections of methylprednisolone. In the greater trochanter region of right femur, defects were created and filled with granules of hydroxyapatite and tricalcium phosphate (HAP/TCP 70/30) or HAP/TCP 70/30 together with 5% strontium. After three months, the animals were euthanized. The bone mass density of the right and left body of femur was measured by cone beam computed tomography (CT) scan. The results of the study showed that the right femur of the rabbit, where biomaterials had been implanted, and the left femur, where no biomaterial implantation occurred, became denser after filling the defect with HAP/TCP 70/30 ceramic granules or 5% Sr modified HAP/TCP ceramic granules. There was no difference between operated and non-operated legs and HAP/TCP and HAP/TCP with 5% strontium groups.
  • No Thumbnail Available
    Item
    Growth factors, genes, bone proteins and apoptosis in the temporomandibular joint (TMJ) of children with ankylosis and during disease recurrence
    (2011) Pilmane, Mara; Skagers, Andrejs; Institute of Anatomy and Anthropology
    AIM OF STUDY was complex detection of appearance and distribution of growth factors, facial bone growth stimulating genes, ground substance proteins and apoptosis in bone of ankylotic TMJ in primary and repeatedly operated children. MATERIALS AND METHODS: Ankylotic tissue was obtained during the arthroplastic surgery from two 6 years old children (boy and girl) with osseous type of disease. The girl underwent the repeated surgery in TMJ due to the same diagnosis in age of 12 years. Ankylotic tissue was proceeded for detection of BMP2/4, TGFβ, Msx2, osteopontin, osteocalcin immunohistochemically, and apoptosis. RESULTS demonstrated massive bone formation intermixed by neochondrogenesis the lack of BMP 2/4, but abundant number of TGFβ-containing cells in bone of all tested cases. Despite rich osteopontin positive structures in bone obtained from both - primary and repeated surgery, osteocalcin demonstrated variable appearance in 6 years aged children, but was abundant in joint 5 years later during disease recurrence. Expression of Msx2 varied widely before, but with tendency to decrease stabilized until few positive cells in bone of 12 years old girl. Apoptosis practically was not detected in primarily operated TMJ, but massively affected the supportive tissue in girl with recurrent ankylosis. CONCLUSIONS: The lack of BMP2/4 expression in ankylotic bone proves the disorders in cellular differentiation with simultaneous compensatory intensification of cellular proliferation and/or growth by rich expression of TGFβ leading to the remodelling of TMJ. Mainly rich distribution of osteocalcin and osteopontin indicate the intensive mineralization processes of ankylotic bone. Persistent Msx2 expression is characteristic for the supportive tissue of recurrent ankylosis of TMJ and indicates the persistent stimulation of bone growth compensatory limitated by massive increase of programmed cell death.
  • No Thumbnail Available
    Item
    Histomorphology of Salivary Glands after Ligature and Reconstruction of Common Carotid Artery in Rabbits
    (2009) Stāmers, Kaspars; Pilmane, Māra; Feldmane, Laila; Pastars, Kalvis; Tomisheva, Nonna; Skagers, Andrejs; Department of Oral and Maxillofacial Surgery and Oral Medicine; Institute of Anatomy and Anthropology
    Introduction. In occlusive diseases of carotid arteries may be involved salivary glands which play important role in oral and general homeostasis.Aim of the study. The purpose of this study was histomorphological evaluation of rabbit’s salivary glands after regional reduction af arterial circulation and reconstruction of ligated common carotid arteries comparing with normal histological sight.Materials and methods. The experiments were authorized by the Animal Ethics Committee of the Latvian Food and Veterinary Service. 20 male Californian rabbits weighing approximately 3 kg were used. Under intravenous general anesthesia and local anesthesia the ligature of a. carotis communis dextra was done. After 28 days 10 rabbits were sacrificed and samples were taken from all major salivary glands and histological measured acinar dimensions and acinar epithelial cell.For rest 10 rabbits under the general anesthesia were performed revascularization of a. carotis communis dextra. After 28 days the rabbits were sacrificed with intrapulmonal injection of T61. The acini dimensions and acinar epithelial cell diameter in microns in all glands were measured except buccal glands were measured. Results. In ischemic conditions all glands react with decrease of acinar epithelial cell diameter and also diametr of functional unit of salivary gland.After revascularisation reestablishment of acini and secretory epithelial cells was observed. Conclusions. Rabbit’s salivary glands have potential to recovery in diminished after ligation of ipsilateral common carotid artery size of acini and secretory epithelium after 4 week ischemia if the blood supply is reestabilished.
  • No Thumbnail Available
    Item
    Hydroxyapatite ceramics for restoration of alveolar bone
    (2008) Šalms, Ģirts; Šalma, Ilze; Skagers, Andrejs; Žīgurs, Guntis; Pilmane, Māra; Vētra, Jānis; Groma, Valērija; Berzina-Cimdina, L.; Rīga Stradiņš University; Institute of Anatomy and Anthropology
  • No Thumbnail Available
    Item
    Radiological evaluation of endodontic treatment of chronic apical periodontitis using biphasic calcium phosphate biomaterial
    (2018) Kurmanalina, Madina A.; Uraz, Raisa M.; Skagers, Andrejs; Locs, Janis; Taganiyazova, Aliya A.; Omargali, Azamat E.
    The article is dedicated to the study of the efficacy of the periapical therapy of chronic periodontitis with the use of synthetic calcium-phosphate biomaterial. 30 patients aged from 22 to 56 years participated in a clinical study. Radiological evaluation was performed by radiovisiography and radiodensitometry. Follow-up examination was carried out at 3, 6 and 12 months. Densitometry indicators at the destruction site showed an increase in radiodensity from 74.2 ± 9.9 units (58.2%) to 111.9 ± 10.6 units (87.8%) after 12 months. Anterior group of teeth demonstrated statistically significant high rate of lesion compaction compared to posterior teeth.
  • No Thumbnail Available
    Item
    Reaction of Subcutaneous Connective Tissue of Experimental Animals on Bone Marrow Mesenchymal Stromal Cell Coated Hydroxyapatite
    (2012) Zavorins, Aleksejs; Pilmane, Māra; Šalms, Ģirts; Skagers, Andrejs; Čakstiņa-Dzērve, Inese; Ločs, Jānis; Institute of Anatomy and Anthropology; Rīga Stradiņš University
    Introduction. Hydroxyapatite (HAp) scaffolds have become an alternative to autologous bone grafts in orthopedic surgery, because it is possible to fill larger scale bone defects and of the decreased operation time and complication risks at the graft donor site, a promising method in bone regeneration is to load bone marrow - mesenchymal stromal cells (BM-MSCs) on to a HAp scaffold. Aim of the Study. The aim of our study is to compare subcutaneous tissue reaction of experimental animals to implantation of HAp and HAp that is coated with BM-MSCs. Materials and Methods. Autologous BM-MSCs were cultivated from crista iliaca dextra biopsy, 4 HAp ceramic implants were coated with BM-MSC and implanted in subcutaneous tissue on one side and non-coated HAp implants on the other side of the spine of 4 rabbits. Immunohistochemical staining of BM-MSC and connective tissue included TUNEL assay, NFkBp105, HSP 70k, Wnt1, TNF-α, VEGF, MMP-2 antibodies, microscoped at 400X magnification and analyzed semiquantitatively. Results. Routine staining with haemotoxilin and eosin demonstrated formation of granulation tissue around the HAp implant, which was more distinct on the control side. There was an increased number of NFκB p105 positive cells (fibroblasts, myocytes, endotheliocytes) on the experimental side (+++), in comparison to the control side (++). HSP70 and apoptosis index was decreased on the experimental side (++ and 60%), in comparison to the control side (+++ and 70%). Number of MMP2 positive structures was increased on the control side in the fibrous capsule (++), in comparison to the experimental side, where the result varied (0 - +) Conclusions. Cultured BM-MSC activity is partly limited due to the apoptosis, which is probably induced by environmental factors. BM-MSC coated HAp implant stimulates secretion of proliferation marker NFkBp105 in subcutaneous tissue, decreases cell stress, apoptosis and tissue degradation (decreased HSP 70, apoptotic cell count and MMP 2) to improve the local tissue quality and proving BM-MSC tissue protective effect.