Implant therapy in the esthetic zone-surgical considerations

Implant placement in the esthetic zone is a complex procedure and requires a restoration-driven approach. Proper selection of patients and implant together with individual assessment of the risk of esthetic complications are very important. Correct 3D-implant positioning and sufficient bone volume should provide long-term esthetic and function. Esthetic region is a zone in which expectations and possibilities collide. Clinician should bring the important decision on the appropriate time of implant placement. Immediate implant placement is particularly challenging in the esthetic zone. Patient desire for reduced treatment time should be weighed against the possible risk factors. Protocol of immediate implant placement in conditions of unfavourable gingival biotypes, the lack of bone or soft tissue in patients with a high smile line lead to esthetic failure which is very important in the esthetic region

Eksperimentalno i kliničko ispitivanje uticaja hirurške tehnike na temperaturu kosti male gustine tokom preparacije ležišta i ugradnje implantata

The posterior maxilla consists of low density bone in which primary stability of the implant which is necessary for unobstructed healing is difficult to obtain. In order to achieve good implant primary stability, the placement of self tapping implants after lateral bone condensing is recommended. During surgical implant procedures, friction heat is generated in the implant site. Bone temperature of 47°C lasting for 1 min destroys the regenerative potential of the bone tissue, causes resorption of the bone and diminishes the mechanic features which can result in early failure of implant therapy. The prevention of excessive heating of the bone tissue during implant site preparation and implant placement is a key requirement for successful osseointegration. The aims of the dissertation are: 1. To compare the bone thermal changes in lateral bone condensing and bone drilling technique. 2. To examine the effect of the temperature of the saline solution for cooling the bone during implant site preparation and implant placement. 3. To compare the bone thermal changes during implant placement after lateral bone condensing technique and bone drilling technique. 4. To compare the bone thermal changes during implant placement using Insertion torque value of 30, 35, 40 Ncm. 5. To compare the bone thermal changes during placement of self tapping and non self tapping implants. 6. To examine the influence of age and gender of the patients on the bone thermal change during implant placement. 7. To examine the influence of bone density at the recipient site as well as region of the implantation on the bone thermal changes during implant placement. In order to study and examine the influence of surgical technique on the temperature of the low density bone in implant site preparation and implant placement, experimental and clinical research has been conducted. In the experimental study as a bone model, a pig rib was used with uniform thickness of the cortical layer of 2mm. The temperature was measured using 3 thermocouples placed in distance of 0,5mm from the implant site, with vertical depth of 1mm, 5mm, 10mm. Two sets of experiments have been conducted. In the first set of experiments, the effect o surgical technique on the bone thermal change was examined during implant site preparation in which lateral bone condensing technique (experimental group) and standard bone drilling technique ( control group ) were compared. Implant site preparation was conducted without irrigation, with irrigation using room temperature saline solution and saline solution of 5 °C. The second set of experiments were conducted with the aim of examining the effect of surgical technique (lateral bone condensing technique and bone drilling) on bone temperature during implant site preparation and implant placement. In the randomized, controlled clinical study, 14 patients were included of both gender (8 women and 6 men) and average age 51.3 ( from 30 to 63), in whose posterior maxilla a total of 30 implants were placed: 15 after lateral bone condensing (study group) and 15 after bone drilling ( control group )...Bočni segment gornje vilice čini kost male gustine u kojoj je teško postići primarnu stabilnost implantata neophodnu za neomeano zarastanje..

Coupling native page/activity-staining with SDS-PAGE/immunodetection for the analysis of glutamine synthetase isoforms in spinach

Glutamine synthetase (GS) is a key nitrogen-assimilating enzyme in plants and a target for the broad-spectrum herbicide glufosinate. Understanding its kinetic and structural properties is of major agricultural importance. Spinach (Spinacia oleracea) is classified as a plant expressing only chloroplastic GS activity. We have analyzed soluble proteins in the spinach by coupling native polyacrylamide gel electrophoresis (PAGE)-activity detection, based on phosphate precipitation, with SDS-PAGE/immunoblotting. One cytosolic (GS1) isoform from the roots and two chloroplastic (GS2) isoforms expressed in leaves were resolved by native PAGE. The identity of the obtained bands was established by the application of GS-specific inhibitors, L-methionine sulfoximine and glufosinate. Examination by sodium dodecyl sulfate (SDS)-PAGE/ Western analysis with anti-GS antibodies, confirmed the identity of the active bands and revealed that both chloroplastic isoforms are composed of 44 kDa subunits, while the cytosolic isoform consists of 40 kDa subunits. The presence of more GS2 isozymes than encoded in the spinach genome is discussed in terms of posttranslational modifications.Projekat ministarstva br. ON17302

Effects of salinity on in vitro growth and photosynthesis of common centaury (Centaurium erythraea Rafn.)

The effects of salinity on in vitro growth, morphogenesis, photosynthetic rate (Pn), PSII efficiency (Fv/Fm), and chlorophyll content were investigated in Centaurium erythraea Rafn. Root growth was more adversely affected by increasing NaCl concentration than was shoot growth. High salt concentrations were effective in induction of axillary and adventitious buds on shoots, with 400 mM NaCl being the most efficient one. Values of Pn and Fv/Fm increased at moderate salt levels, but decreased when 400 mM NaCl was applied. Chlorophyll a and b contents and total chlorophyll had a decreasing trend with increasing supply of NaCl in the growth medium. .Praćen je efekat NaCl (u rasponu koncentracija od 0 do 400 mM) na rast, morfogenezu, intenzitet fotosinteze (Pn), efikasnost fotosistema II (Fv/Fm) i sadržaj hlorofila a i b kod vrste Centaurium erythraea Rafn. u in vitro uslovima. Utvrđeno je da su koreni kičice osetljiviji na visoke koncentracije soli u hranljivoj podlozi u poređenju sa izdancima. Visoke koncentracije soli su se pokazale efikasnim u pogledu indukcije formiranja aksilarnih i adventivnih pupoljaka na izdancima. U uslovima umerenog stresa (100 i 200 mM NaCl), vrednosti Pn i Fv/Fm rastu u poređenju sa vrednostima dobijenim kod kontrolne grupe biljaka. Primena 400 mM NaCl dovela je do opadanja vrednosti Pn i Fv/Fm ispod kontrolnih vrednosti. Sadržaj hlorofila a i b, kao i ukupnog hlorofila opada sa porastom sadržaja soli u hranljivoj podlozi. Odnos Chl a/b takođe opada. Može se zaključiti da je Centaurium erythraea Rafn vrsta koja je otporna na povećani salinitet podloge u kojoj raste. Prema tome, može se pretpostaviti da je komercijalno gajenje ove vrste kičice ostvarivo na zaslanjenim terenima. .nul

Supplementary data for article: Banjanac, T.; Dragićević, M.; Šiler, B.; Gašić, U.; Bohanec, B.; Nestorović Živković, J.; Trifunović, S.; Mišić, D. Chemodiversity of Two Closely Related Tetraploid Centaurium Species and Their Hexaploid Hybrid: Metabolomic Search for High-Resolution Taxonomic Classifiers. Phytochemistry 2017, 140, 27–44. https://doi.org/10.1016/j.phytochem.2017.04.005

Supplementary material for: [https://doi.org/10.1016/j.phytochem.2017.04.005]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2477

Rapid in vitro selection of salt-tolerant genotypes of the potentially medicinal plant Centaurium maritimum (L.) fritsch

We investigated differences of salinity tolerance between 'salt-tolerant' (ST) and 'salt-sensitive' (SS) genotypes of yellow centaury [Centaurium maritimum (L.) Fritsch] selected during the germination phase. The ability of in vitro cultured C. maritimum to complete the whole ontogenetic cycle in less than 6 months enabled us to deterine salinity tolerance during different growth phases. Based on the physiological attributes measured in this study (growth, morphogenesis, photosynthesis, flowering, seed germination), it can be concluded that C. maritimum genotypes differing in salinity tolerance showed a variable response to elevated salt concentrations during both the vegetative and the generative growth phase.Vršena su istraživanja u cilju utvrđivanja razlika u tolerantnosti na povećani salinitet između in vitro selekcionisanih 'salt tolerant' (ST) i 'salt sensitive' (SS) genotipova žute kičice [Centaurium maritimum (L.) Fritsch]. Sposobnost vrste C. maritimum da kompletira ontogenetski ciklus u in vitro uslovima za manje od 6 meseci, omogućila je praćenje tolerancije na povećani salinitet tokom različitih faza razvića. Ako se uzmu u obzir svi fiziološki parametri koji su praćeni u ovom istraživanju (rastenje, morfogeneza, fotosinteza, cvetanje, klijanje semena), može se zaključiti da selekcionisani STi SS genotipovi zaista pokazuju različit odgovor u uslovima u uslovima povećanog saliniteta, kako tokom vegetativne faze, tako i tokom generativne faze razvića.Projekat ministarstva br. 14303

Coupling native page/activity-staining with SDS-PAGE/immunodetection for the analysis of glutamine synthetase isoforms in spinach

Glutamine synthetase (GS) is a key nitrogen-assimilating enzyme in plants and a target for the broad-spectrum herbicide glufosinate. Understanding its kinetic and structural properties is of major agricultural importance. Spinach (Spinacia oleracea) is classified as a plant expressing only chloroplastic GS activity. We have analyzed soluble proteins in the spinach by coupling native polyacrylamide gel electrophoresis (PAGE)-activity detection, based on phosphate precipitation, with SDS-PAGE/immunoblotting. One cytosolic (GS1) isoform from the roots and two chloroplastic (GS2) isoforms expressed in leaves were resolved by native PAGE. The identity of the obtained bands was established by the application of GS-specific inhibitors, L-methionine sulfoximine and glufosinate. Examination by sodium dodecyl sulfate (SDS)-PAGE/ Western analysis with anti-GS antibodies, confirmed the identity of the active bands and revealed that both chloroplastic isoforms are composed of 44 kDa subunits, while the cytosolic isoform consists of 40 kDa subunits. The presence of more GS2 isozymes than encoded in the spinach genome is discussed in terms of posttranslational modifications.Projekat ministarstva br. ON17302

Pursuit for est microsatellites in a tetraploid model from de novo transcriptome sequencing

Available scientific literature reports very few microsatellite markers derived from tetraploid genomes using de novo transcriptome sequencing, mostly because their gain usually represents a major computational challenge due to complicated combinatorics during assembly of sequence reads. Here we present a novel approach for mining polymorphic microsatellite loci from transcriptome data in a tetraploid species with no reference genome available. Pairs of 114 bp long de novo sequenced transcriptome reads of Centaurium erythraea were merged into short contigs of 170-200 bp each. High accuracy assembly of the pairs of reads was accomplished by a minimum of 14 bp overlap. Sequential bioinformatics operations involved fully free and open-source software and were performed using an average personal computer. Out of the 13 150 candidate contigs harboring SSR motifs obtained in a final output, we randomly chose 16 putative markers for which we designed primers. We tested the effectiveness of the established bioinformatics approach by amplifying them in eight different taxa within the genus Centaurium having various ploidy levels (diploids, tetraploids and hexaploids). Nine markers displayed polymorphism and/or transferability among studied taxa. They provided 54 alleles in total, ranging from 2 to 14 alleles per locus. The highest number of alleles was observed in C. erythraea, C. littorale and a hybridogenic taxon C. pannonicum. The developed markers are qualified to be used in genetic population studies on declining natural populations of Centaurium species, thus providing valuable information to evolutionary and conservation biologists. The developed cost-effective methodology provides abundant de novo assembled short contigs and holds great promise to mine numerous additional EST-SSR-containing markers for possible use in genetics population studies of tetraploid taxa within the genus Centauriu

Phenotypic and Genetic Variation of an Interspecific Centaurium Hybrid (Gentianaceae) and Its Parental Species.

Interspecific hybridization is one of the major actuators of evolutionary changes in plants. As the result of allopolyploid hybridization, offspring may gain different ploidy levels in comparison to parental species, which can provide them instant reproductive isolation. Two tetraploid sister species, Centaurium erythraea and C. littorale, readily cross-fertilize, resulting in hybrids of various ploidy. In northern Serbia, two stable populations of a hexaploid taxon C. pannonicum have been documented. It has been proposed previously that this taxon emerged after an interspecific hybridization event between two tetraploid sister-species: C. erythraea and C. littorale subsp. compressum. The existing populations of the hybridogenic taxon, as well as neighboring populations of the two parental taxa were here characterized by both morphometrics and molecular markers (EST-SSR and trnL-F). Three leaf and two flower characteristics were found to be informative in delimitation of the parental taxa and in their discernment from hybrid individuals, the latter having intermediate values. Eight microsatellite markers were found to have good ability to distinguish studied taxa, placing C. pannonicum in closer relationship with C. erythraea. Conversely, trnL-F plastid marker nominated C. littorale subsp. compressum to be the donor of the C. pannonicum plastid DNA. Reproductive isolation of the hexaploid hybrid individuals from the parental species should be examined as the next logical step in describing the new species

Implantatna stabilnost i nivo marginalne kosti kod cirkonijum endoosealnih implantata sa mikrostrukturiranom površinom - tromesečna eksperimentalna studija na psima

Background/Aim. The modification of implant surfaces could affect mechanical implant stability as well as dynamics and quality of peri-implant bone healing. The aim of this 3-month experimental study in dogs was to investigate implant stability, marginal bone levels and bone tissue response to zirconia dental implants with two laser-micro-grooved intraosseous surfaces in comparison with nongrooved sandblasted zirconia and sandblasted, high-temperature etched titanium implants. Methods. Implant surface characterization was performed using optical interferometric profilometry and energy dispersive X-ray spectroscopy. A total of 96 implants (4 mm in diameter and 10 mm in length) were inserted randomly in both sides of the lower jaw of 12 Fox Hound dogs divided into groups of 24 each: the control (titanium), the group A (sandblasted zirconia), the group B (sandblasted zirconia plus microgrooved neck) and the group C (sandblasted zirconia plus all microgrooved). All the implants were immediately loaded. Insertion torque, periotest values, radiographic crestal bone level and removal torque were recorded during the 3-month follow-up. Qualitative scanning electon microscope (SEM) analysis of the bone-implant interfaces of each group was performed. Results. Insertion torque values were higher in the group C and control implants (p lt 0.05). Periotest values increased in all the periods in proportion to the extent of microgrooving as follows: the group C > the control > the group B > the group A (p lt 0.05). Radiographic measurements showed minimal crestal bone loss at 3 months for microgrooved zirconia implants (groups C and B) and control implants compared with the group A implants (p lt 0.05). The removal torque values increased with time for all the groups as follows: the group C > the control > the group B > the group A (p lt 0.05). SEM showed that implant surfaces of the groups B and C had an extra bone growth inside the microgrooves that corresponded to the shape and direction of the microgrooves. Conclusion. The addition of microgrooves to the entire intraosseous surface of zirconia dental implants enhances primary and secondary implant stability, promotes bone tissue in growth and preserves crestal bone levels.Uvod/Cilj. Modifikacija površine implantata može uticati na njegovu mehaničku stabilnost kao i na dinamiku i kvalitet periimplantatnog koštanog zarastanja. Cilj ove tromesečne eksperimentalne studije na psima bio je da se ispita stabilnost implantata, nivo marginalne kosti i odgovor koštanog tkiva na cirkonijum endoosealne implantate sa dve intraosealne površine mikrostrukturirane laserom u poređenju sa peskiranim cirkonijum implantatima čija površina nije mikrostrukturirana kao i sa titanijum implantatima čije su površine peskirane i nagrižene visokom temperaturom. Metode. Karakterizacija površine implantata učinjena je optičkom interferometrijskom profilometrijom i analizom energetskog spektra pri difrakciji X-zračenja. Ukupno 96 implantata (prečnika 4 mm i dužine 10 mm) ugrađeno je nasumično i obostrano u donju vilicu kod 12 pasa (lisičara) i podeljeno u četiri grupe po 24: kontrolna (titanijum implantati); grupa A (peskirani cirkonijum implantati); grupa B (peskirani cirkonijum implantati sa mikrokanalima u koronarnoj trećini); grupa C (peskirani cirkonijum implantati sa mikrokanalima duž cele površine). Svi implantati su odmah opterećeni. Meren je obrtni momenat pri ugradnji implantata, vrednosti periotesta, radiografski nivo marginalne kosti i obrtni moment za uklanjanje implantata tokom tromesečnog perioda praćenja. Međuspoj kosti i implantata iz svake grupe ispitivan je kvalitativnom skenirajućom elektronskom mikroskopijom (SEM). Rezultati. Veći obrtni momenat zabeležen je pri ugradnji implantata kod grupe C i kontrolne grupe (p lt 0,05). U ispitivanom vremenskom periodu, vrednosti periotesta uvećavale su se srazmerno obimu mikrostrukturiranja površine i to: grupa C > kontrolna grupa > grupa B > grupa A (p lt 0,05). Radiografskom analizom utvrđen je minimalni gubitak marginalne kosti u trećem mesecu praćenja oko cirkonijum implantata sa mikrokanalima (grupa B i C) i kontrola u poređenju sa implantatima grupe A (p lt 0,05). Vrednosti obrtnog momenta za uklanjanje implantata vremenom su se uvećavale u svim grupama na sledeći način: grupa C > kontrolna grupa > grupa B > grupa A (p lt 0,05). Kod implantatnih površina grupa B i C, SEM je pokazala dodatni rast koštanog tkiva unutar mikrokanala koji odgovara njihovom obliku i pravcu. Zaključak. Formiranje mikrokanala duž cele intraosealne površine cirkonijum endoosealnih implantata povećava primarnu i sekundarnu implantatnu stabilnost, podstiče urastanje koštanog tkiva i održava nivo marginalne kosti