Over the last 20 years "composite" insulators have been increasingly used in high voltage applications as an alternative traditional materials. More recently, polydimethylsiloxane (PDMS) have been used as weather sheds on these composite insulators. The main attraction with PDMS is that the surface hydrophobicity can be recovered following pollution or surface discharges. Among the possible mechanisms for recovery the most likely is the migration of low molecular weight silicone oil (LMWS) from the bulk to the surface encapsulating pollutant particles. Although it is widely recognised that the migration of LMWS is the cause of this recovery of hydrophobicity, the mechanism of what actually occurs is not well understood. It is also not known for how long this process will continue. The main objective of this study program was to gain improved understanding of the surface hydrophobic recovery process that is unique to polydimethlysiloxane high-voltage insulators. Fundamental knowledge of this mechanism has been increased through the development of the Contact Angle DRIFT Electrostatic Deposition (CADED) novel analytical technique. This technique enabled study of the degradation of silicone elastomers subjected to high voltage environments by closely following LMWS migration from the bulk material to the surface and linking it to the contact angle measurements. The migration rate data showed that the aged material recovered faster that the virgin material. Differences in the rate and maximum surface levels of silicone were seen between materials from different manufacturers. This has significant implications for the life-time of these materials A model system has been developed to examine LMWS diffusion through the bulk material and into the interface of surface and pollutant. This was achieved by examining theoretical and empirically derived equations and using existing experimental data to better understand the mechanism of recovery. This diffusion was Fickian in the initial stages of recovery. X-ray photoelectron spectroscopy (XPS) and contact angle measurements were used to substantiate the degree of degradation in in-field silicone insulators by quantifying the levels of the major degradation products: silica and silica-like material and alumina.

Made available in DSpace on 2014-06-11T19:25:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-08-22Bitstream added on 2014-06-13T19:11:58Z : No. of bitstreams: 1 franca_dcc_me_araca.pdf: 2609587 bytes, checksum: 8a7904cdb64c406b06f726af6ac60fbc (MD5) / Universidade Estadual Paulista (UNESP) / No presente estudo foram utilizados 60 ratos submetidos a implantes subcutâneos de quatro elastômeros de silicone, sendo três usados em prótese bucomaxilofacial, LIM 6050, MDX 4-4210 e Silastic 732 RTV industrial e um indicado para cirurgia plástica, o Silimed. O objetivo do estudo foi avaliar os materiais em relação à compatibilidade biológica tecidual, nos tempos pós-operatórios de sete, quinze e trinta dias, quando os animais foram sacrificados e as peças processadas e coradas pela hematoxilina e eosina para análise qualitativa e quantitativa dos espécimes. Pelo estudo histomorfométrico, oito áreas de 60,11 mm2 foram analisadas, contando-se as células mesenquimais, inflamatórias mononucleares, eosinófilos e as células gigantes do tipo corpo estranho. O experimento foi desenvolvido em dois capítulos, estudando-se separadamente os silicones de uso em prótese e o Silimed. No primeiro capítulo, a análise da biocompatibilidade dos implantes subcutâneos dos elastômeros de silicone LIM 6050, MDX 4-4210 e Silastic 732 RTV industrial, observou-se biocompatibilidade aceitável em todos eles, considerando-se o fato de que sua indicação protética dependeria em especial das características físicas próprias de cada material, pela mínima reação tecidual observada, além de que em sua forma sólida é fácil a adaptação aos tecidos. No segundo capítulo, o estudo se baseou na análise das reações referentes ao implante de silicone utilizado em cirurgia plástica (Silimed), constatando-se a presença de processo inflamatório ligeiramente maior no silicone gel em relação aos outros grupos, porém com níveis aceitáveis de biocompatibilidade, confirmada pela rara presença de células gigantes do tipo corpo estranho. Todos os dados foram submetidos à análise de variância e teste de Tukey, demonstrando que todos os materiais implantados iniciaram uma resposta... / In the present study 60 rats were submitted to subcutaneous implant of four elastomers of silicon, being three of use in bucomaxillofacial prosthesis, LIM 6050, MDX 4-4210 and Silastic 732 RTV industrial and a suitable one for plastic surgery, Silimed. The objective of the study was to evaluate the materials in relation to the tissue biological compatibility, in the postoperative times of seven, fifteen and thirty days, when the animals were sacrificed and the processed pieces and stained for the hematoxilin and eosin for qualitative and quantitative analysis of the specimens. For the histomorphometric study, eight areas of 60,11 mm2 were analyzed, being counted the mesenchimal cells, inflammatory cells, eosinophile and giant cells. The experiment was developed in two chapters, being studied the use silicons separately in prosthesis and Silimed. In the first chapter, the analysis of the biocompatibility of the subcutaneous implant of the elastomers of silicon LIM 6050, MDX 4-4210 and Silastic 732 RTV industrial, acceptable biocompatibility was observed in all of them, being considered the fact that your prosthetic indication would especially depend on the own physical characteristics of each material, for the low tissue reaction observed, in addition in your solid form it is easy the adaptation to the tissues. In the second chapter, the study based on the analysis of the referring reactions to the it implants of silicon used in plastic surgery (silimed), being verified the presence of inflammatory process lightly larger in relation to the other groups, however with acceptable levels of biocompatibility confirmed by the rare presence of giant cells of the type strange body. All the data were submitted to the variance analysis and test of Tukey, demonstrating that all the implanted materials began an acceptable tissue inflammatory reaction, with tissue reactions of light intensity the moderate... (Complete abstract, click electronic address below)

La famille des élastomères silicones LSR (Liquid Silicone Rubber) de haute technicité est identifiée comme celle possédant les plus forts arguments de développement au cours des prochaines décennies en raison de leurs propriétés spécifiques et de leurs facilités de mise en forme en grande série. Notamment, le moulage par injection du LSR sur d’autres matières telles que les thermoplastiques ou les métaux est aujourd’hui possible, ce qui ouvre la possibilité d’obtenir des composants multi-matières, multi-couleurs et de nouvelles fonctionnalités. Cette thèse se concentre sur la transformation des élastomères silicones LSR dans le but de mieux appréhender les phénomènes impliqués, afin d’améliorer les procédés d’élaboration et d’optimiser les conditions de transformation des composants élastométriques mono ou bi-matières à géométrie et propriété fonctionnelle bien définie. Les comportements rhéologique, cinétique et thermique des élastomères silicones ont été étudiés et caractérisés sous des conditions réelles de mise en œuvre par différentes méthodes associées. Un modèle thermo-rhéo-cinétique a été développé et ensuite implémenté dans un code de calcul de remplissage Cadmould® pour simuler le moulage par injection des élastomères silicones LSR ou encore le surmoulage de thermoplastiques. Pour la validation des modèles choisis et des paramètres identifiés, les essais d’injection sur l’outillage industrielle instrumenté ont été réalisés et confrontés à des résultats numériques obtenus. Enfin, la caractérisation de l’adhésion et l’adhérence interfaciale entre les thermoplastiques et les élastomères silicones a été réalisé sous différentes sollicitations complexes. De plus, l’évolution d’adhérence interfaciale des assemblages collés au cours de la vulcanisation des élastomères silicones a été caractérisée par l’essai de traction en utilisant un rhéomètre rotatif sous différentes modes de chauffage. / The family of high technology silicone elastomers LSR (Liquid Silicone Rubber) is identified as having the strongest arguments for development in the coming decades due to their unique properties and easy forming in large series. In particular, the injection molding of LSR on other materials such as thermoplastics or metals is possible today, which opens the possibility of obtaining multi-material, multi-color and new features components. The work presented in this thesis focuses on the transformation of silicone elastomers in order to better understand the phenomena involved, as to improve production processes and optimize processing conditions for mono or bi-material components in geometry and property functional well defined. The rheological, curing kinetic and thermal behaviors of silicone elastomers have been studied and characterized under real conditions of production by different methods combined. A thermo-rheo-kinetic model was then developed and implemented in commercial computer software Cadmould® to simulate the injection molding process of LSR or the overmolding process of LSR on to thermoplastics. For the validation of the models chosen and the parameters identified, the injection molding tests on industrial instrumented tools were performed and compared to numerical results. Finally, the characterization of interfacial adhesion between the thermoplastic and silicone elastomers was carried out under various adhesion tests. Moreover, the evolution of interfacial adhesion in thermoplastic/silicone components during the vulcanization of silicone elastomers has been characterized by the tensile test using a rotating rheometer in different heating cycles

Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-03T16:47:38Z No. of bitstreams: 1 jaianebandolimonteiro.pdf: 2039791 bytes, checksum: c3f28c1a95fdef73d0cc0190a9dfa169 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2015-12-03T21:29:38Z (GMT) No. of bitstreams: 1 jaianebandolimonteiro.pdf: 2039791 bytes, checksum: c3f28c1a95fdef73d0cc0190a9dfa169 (MD5) / Made available in DSpace on 2015-12-03T21:29:38Z (GMT). No. of bitstreams: 1 jaianebandolimonteiro.pdf: 2039791 bytes, checksum: c3f28c1a95fdef73d0cc0190a9dfa169 (MD5) Previous issue date: 2015-04-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo foi avaliar a alteração dimensional dos moldes de silicona por condensação imediatamente, 30min, 1h e 7 dias após a moldagem, com o auxílio da máquina de medição tridimensional por coordenadas. Os grupos foram divididos em: G1: Speedex Putty/Speedex Light Body (Coltene/Vigodent AS Indústria e Comércio), G2: Optosil P Plus/Xantopren L Blue (Heraeus Kulzer GmbH), G3: Zetaplus Putty/Oranwash L (Zhermack SpA) e G4: Precise SX (Dentsply Indústria e Comércio Ltda). Para a obtenção das 80 medições dos 4 materiais (n=20), foi usado um dispositivo composto por uma moldeira perfurada e uma outra parte com 3 edentações pré-estabelecidas. Para a avaliação dimensional, a máquina Crysta-Plus M 574 (Mitutoyo) realizou cada medida 3 vezes nos tempos estabelecidos e obteve-se a média aritmética. A média final das 4 distâncias I, II, III e IV do dispositivo edentado foi novamente aplicada. A análise estatística foi realizada com o teste de Kolmogorov-Smirnov que rejeitou a hipótese nula de distribuição assimétrica. Posteriormente, foi feita a ANOVA para comparar os 4 materiais simultaneamente e o teste paramétrico t de Student para comparar os materiais 2 a 2. O nível de significância global foi de p≤0,05. A maior contração linear foi observada na Speedex, mas não foi significante (p=0,08). A Zetaplus Putty/Oranwash L parece ser a mais estável (p=0,99), mas não foi significante. Não houve diferença estatisticamente significante entre nenhuma silicona por condensação quando comparadas simultaneamente nos 4 tempos ou quando comparadas 2 a 2, à exceção, Precise SX e a Speedex (p=0,05) no tempo T3. Todas as siliconas por condensação testadas apresentam alteração dimensional clinicamente aceitável e podem ser vazadas imediatamente, 30min, 1h e 7 dias após a moldagem. / The purpose was to evaluate the dimensional changes of condensation silicone impressions by immediately, 30min, 1h and 7 days after impression, with the help of threedimensional measuring coordinate machine. The groups were divided in: G1: Speedex Putty/Speedex Light Body (Coltène/Vigodent S/A Ind and Com), G2: Optosil P Plus/Xantopren L Blue (Heraeus Kulzer GmbH), G3: Zetaplus Putty/Oranwash L (Zhermack SpA) and G4: Precise SX (Dentsply Ind and Com Ltda). To obtain 80 measurements of 4 material (n=20) was used a device consisting of a perforated tray and one another part with 3 pre-established indentations. For dimensional evaluation, the Crysta-Plus M574 machine (Mitutoyo) held each measurement 3 times at the established times and obtained the arithmetic mean. The final average of the 4 distances of I, II, III and IV the edentulous device was again applied. Statistical analysis was performed using the Kolmogorov-Smirnov test to reject the null hypothesis of asymmetric distribution. Subsequently, ANOVA was performed to compare the four materials simultaneously and Student's t parametric test to compare the 2 by 2 materials. The overall significance level of p≤0,05. The higher linear contraction was observed in Speedex, but was not significant (p=0,08). The Zetaplus Putty/Oranwash L seems to be more stable (p=0,99) but was not significant. There was no significant difference between any silicone condensation compared simultaneously in 4 times or compared 2 by 2, except, Precise SX and Speedex (p=0,05) in T3 time. All tested condensation silicones exhibit clinically acceptable dimensional change and can be leaked immediately, 30min, 1h and 7 days after impression.

<p>Najče&scaron;ća komplikacija nakon ugradnje silikonskih implantata za dojku je kontraktura fibrozne kapsule (KK), koja se normalno stvara oko implantata u sklopu reakcije oko stranog tela. Najozbiljnija komplikacija nakon ugradnje silikonskih implantata za dojku je anaplastični krupnoćelijski limfom koji se javlja isključivo kod pacijentkinja koje imaju ugraĎene implantate (eng. Breast-implant associated anaplastic large cell lymphoma &ndash; BIA ALCL). Uzrok nastanka ovih komplikacija ostaje nepoznat. Ustanovljeno je da se KK manje javlja kod implantata koji imaju makroteksturisanu povr&scaron;inu i kod onih koji su presvučeni poliuretanskom penom. S druge strane, BIA-ALCL se če&scaron;će dijagnostikuje kod pacijentkinja kojima su ugraĎeni upravo makroteksturisani implantati. Subklinička infekcija koja predstavlja odgovor organizma na postojanje biofilma na ugraĎenim implantatima, predstavlja jedan od najznačajnijih etiolo&scaron;kih faktora za nastanak KK i BIA-ALCL. Biofilm je konglomerat mirkoorganizama uronjenih u matriks koji ih &scaron;titi od dejstva antibiotika i antiseptika. Kako je nemoguće delovati medikamentozno na eradikaciju biofilma, brojni autori daju razne preporuke u cilju izbegavanja kontaminacije implantata tokom operativnog zahvata, a time i formiranja biofilma. Pored brojnih mera, savetuje se i ispiranje džepa u koji će se plasirati proteza kao i same proteze, nekim od antiseptičkih ili antibiotskih rastvora. Do sada ne postoje prihvaćene jasne preporuke o načinu ispiranja različitih implantata, objavljena su samo lična iskustva raznih autora. Ciljevi ovog istraživanja su bili da se ustanovi mogućnost formiranja biofilma četiri različite bakterije (Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa i Ralstonia pickettii) na tri različito teksturisana silikonska implantata za dojku (sa porama veličine 70-150 &mu;m, 50&ndash;900 &mu;m i 13 &mu;m) u in vitro uslovima; da se ispita da li ispiranje antisepticima (oktenidindihidrohloridom i povidon jodom), ili antibiotikom (cefuroksimom) ili istovremeno me&scaron;avinom povidon joda i antibiotika pre bakterijske kontaminacije sa četiri različite bakterije ima uticaja na formiranje biofilma na tri različito teksturisana implantata za dojke u in vitro uslovima; i da se ispita efekat antiseptika u odnosu na efekat antibiotika na formiranje bakterijskog biofilma na tri različito teksturisana silikonska implantata za dojku. Istraživanje je koncipirano kao prospektivna studija u vidu eksperimenta koji je izveden u Laboratoriji za mikrobiologiju, Instituta za javno zdravlje Vojvodine u Novom Sadu. Za izvoĎenje eksperimenta kori&scaron;ćeni su uzorci tri vrste silikonskih implantata za dojku sa različito teksturisanom povr&scaron;inom, odnosno porama različite veličine: 70-150 &mu;m, 50&ndash;900 &mu;m, i 13 &mu;m. Od svakog od navedenih implantata su pravljeni uzorci, sečenjem kapsula implantata na komadiće veličine 1x1 cm. Ukupno je bilo 1440 uzoraka. Na osnovu teksture uzorci su podeljeni u tri grupe: Grupa 1 (pore veličine 70-150 &mu;m), Grupa 2 (pore veličine 50&ndash;900 &mu;m) i Grupa 3 (pore veličine 13 &mu;m). Svaka od ovih grupa je dalje podeljena u jednu kontrolnu grupu i po četiri ispitivane grupe. Nakon sterilizacije uzoraka svaka kontrolna grupa je kontaminirana sa po 100&mu;l bakterijskog bujona Staphylococcus epidermidis (n=30), Staphylococcus aureus (n=30), Pseudomonas aeruginosa (n=30) i Ralstonia pickettii (n=30). Ispitivane grupe se bile podeljene prema načinima ispiranja na one u kojima su uzorci prvo ispirani: oktenidin &ndash; dihidrohloridom ili povidon jodom ili cefuroksimom ili kombinacijom povidon joda i dva antibiotika, pa potom kontaminirani sa po 100&mu;l bakterijskog bujona Staphylococcus epidermidis (n=30), Staphylococcus aureus (n=30), Pseudomonas aeruginosa (n=30) i Ralstonia pickettii (n=30). Po zavr&scaron;enoj kontaminaciji, uzorci su se inkubirali na temperaturi od 37&deg;C u trajanju od 96h, čime su stvoreni uslovi za formiranje biofilma. Nakon inkubacije, svaki pojedinačni uzorak je uronjen u sterilan tripton soja bujon, izlagan soničnoj energiji u trajanju od 1minuta i zatim vorteksiran 1 minut, čime je omogućeno odvajanje nastalog biofilma od implantata. Za ispitivanje sposobnosti formiranja biofilma kori&scaron;ćena je modifikovana tehnika sa mikrotitar pločom po Stepanoviću. Rezultati su pokazali da sve četiri ispitivane bakterije S. epidermidis, S. aureus, P. aeruginosa i Ralstonia pickettii statistički značajno vi&scaron;e stvaraju biofilm na implantatima sa porama veličine 50&ndash;900 &mu;m u odnosu na pore 70-150 &mu;m i u odnosu na pore veličine 13 &mu;m. Biofilm se statistički značajno vi&scaron;e stvara na porama veličine 70-150 &mu;m u odnosu na pore 13 &mu;m. Jedini izuzetak je Pseudomonas aeruginosa kod kojeg ne postoji statistični značajna razlika u produkciji biofilma na teksturisanim implantatima sa porama veličine 70-150 &mu;m u odnosu na one sa porama 13 &mu;m. TakoĎe, sve četiri ispitivane bakterije statistički značajano manje stvaraju biofilm nakon ispiranja povidon jodom, oktenidin-dihidrohloridom ili rastvorom antibiotika u sve tri grupe implantata, u odnosu na povr&scaron;ine koje nisu ispirane. Izuzetak je S. epidermidis u Grupi 3 kod kojeg nije utvrĎeno statistički značajno manje formiranje biofilma nakon ispiranja oktenidin dihidrohloridom u odnosu na neispiranje. Cefuroksim je bio efikasniji u sprečavanju formiranja biofilma sve četiri ispitivane bakterije u odnosu na neispiranje u Grupi 1, kao i za S. epidermidis i Ralstoniu Pickettii u Grupi 2. Cefuroksim se nije pokazao statistički značajno efikasnim u sprečavanju formiranja biofilma S. aureus i P. aeruginosa u Grupi 2, kao ni kod jedne bakterije u Grupi 3. Dalje je dokazano da su antiseptici (oktenidin-dihirohlorid i povidon jod) kao i me&scaron;avina povidon joda i dva antibiotika (cefuroksim i gentamicin), statistički značajno efikasnji od ispiranja samo antibiotikomcefuroksimom u smanjenju formiranja biofilma sve četiri ispitivane bakterije kod sva tri ispitivana, različito teksturisana silikonska implantata. Rezultati su pokazali da je ispiranje povidon jodom statistički značajno efikasnije u prevenciji stvaranja biofilma kod skoro svih ispitivanih bakterija od ispiranja oktenidin- dihidrohloridom u sve tri grupe implantata. Statistički značajna razlika nije utvrĎena u prevenciji stvaranja biofilma Staphylococcus aureusa kod sve tri grupe implantata prilikom ispiranja povidon jodom u odnosu na oktenidin- dihidrohlorid, kao i kod Ralsotnia pickettii u Grupi 2. Na osnovu rezultata ove studije, preporuka je da se koriste mikroteksturisani implantati kao i da se oni, pre ugradnje isperu povidon jodom ili me&scaron;avinom povidon jod i dva antibiotika (cefuroksim i gentamicin), u cilju prevencije stvaranja biofilma, a time i postoperativnih komplikacija koje mogu nastati nakon ugradnje implantata.</p> / <p>The most common complication after breast implant surgery is contracture of capsule, which is normally formed around implants as part of foreign body reaction. The most sincere complication after this kind of surgery is breast implant associated anaplastic large cell lymphoma (BIA-ALCL). The cause of these complications is still unknown. It is evident that capsular contracture (CC) is seen less frequently in patients with macro-textured implants and in those with implants covered with polyurethane foam. On the other hand, BIA-ALCL is diagnosed more frequently in patients with those, macro-textured implants. Subclinical infection, defined as an response of organism on presence of biofilm on the implant, is considered to be one of the most important etiologic factors for CC and BIA-ALCL. Biofilm is a conglomerate of microorganisms immersed into matrix, which protects them from influence of antibiotics and antiseptics. As it is impossible to eradicate biofilms with medicaments, many authors suggest different steps in order to avoid contamination of the implant during the operation and therefore, prevent the formation of biofilm. Among many tips, it is recommended to irrigate the pocket for breast implant and the implant itself, with some antiseptic or antibiotic solution. Up till now, there is no agreed consensus on the type of irrigation for different implants. Only personal experiences of a few authors have been published. Aims of this research were: to establish the possibility of biofilm formation of four different bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa and Ralstonia pickettii) on three differently textured breast implants (with pore diameter of 70-150 &mu;m, 50&ndash;900 &mu;m and 13 &mu;m) in vitro; to examine whether the irrigation of implant with antiseptics (povidone iodine and octenidine dihydrochloride), antibiotics (cefuroxime) or mixture of povidone iodine and two antibiotics, before the contamination with bacteria, has an influence on the incidence on biofilm formation on three differently textured implants; and to examine the effect of antiseptics in contrast to the effect of antibiotics on biofilm formation on three differently textured breast implants. The study was conducted as a prospective research that took place at the Laboratory for microbiology, at the Institute of public health of Vojvodina in Novi Sad. For the experiment, three types of silicone breast implants were used with different pore sizes: 70-150 &mu;m, 50&ndash;900 &mu;m and 13 &mu;m. Samples were made by cutting each of these types of implants into pieces sized 1x1cm. There were 1440 samples in total. According to texture, samples were divided it three groups: Group 1 (pore size 70-150 &mu;m), Group 2 (pore size 50&ndash;900 &mu;m) and Group 3 (pore size 13 &mu;m). Furthermore, each of these groups was divided in one control and four test groups. After sterilisation of samples, every control group was contaminated with 100&mu;l of bacterial broth of Staphylococcus epidermidis (n=30), Staphylococcus aureus (n=30), Pseudomonas aeruginosa (n=30) and Ralstonia pickettii (n=30). Tested groups were divided according to type of irrigation into those where samples were firstly irrigated with either: octenidine dihydrochloride of povidone iodine or cefuroxime of mixture of povidone iodine with two antibiotics, and after the irrigation, contaminated with 100&mu;l bacterial broth of Staphylococcus epidermidis (n=30), Staphylococcus aureus (n=30), Pseudomonas aeruginosa (n=30) and Ralstonia pickettii (n=30). After contamination, samples were incubated on 37&deg;C for 96h, which created excellent conditions for biofilm formation. After incubation, each sample was dipped into sterile tripton soy broth, and then exposed to sonic energy for 1 minute and vortexed for 1 minute, which made biofilm separate from the implant. For testing the capability of biofilm formation, modified technique with microtitar plates described by Stepanović was used. Results show that all four examined bacteria S. epidermidis, S. aureus, P. aeruginosa and Ralstonia pickettii form more biofilm on implants with pore sizes 50&ndash;900 &mu;m compared to implants with pore size 70-150 &mu;m and those with 13 &mu;m. Statistical significance was found in biofilm formation on implants with pores 70-150 &mu;m compared to implants with pores 13 &mu;m. Furthermore, all four examined bacteria form statistically less biofilm after the irrigation with any of used solutions: povidone iodine, octenidine dihydrochloride, antibiotic solution of mixture of povidone iodine and two antibiotics, in all three groups of implants compared to surfaces that were not irrigated. The exception is S. epidermidis in Group 3, where no statistical significance was found on biofilm formation after the irrigation with octenidine dihydrochloride compared to non-irrigation. Cefuroxime was more efficient in biofilm prevention for all four tested bacteria compared to non-irrigation in Group 1 and for S. epidermidis and Ralstonia pickettii in Group 2. There was no statistical significance found in prevention of S. aureus i P. aeruginosa biofilms when irrigating with cefuroxime in Group 2, as well as for all tested bacteria in Group 3. Furthermore, it was verified that antiseptics (octenidin dihydrochloride and povidone iodine) and mixture of povidone iodine and two antibiotics (cefuroxime and gentamycin), were statistically more efficient in biofilm prevention of all four examined bacteria in all groups of implants, compared to irrigation with antibiotic-cefuroxime alone. Results show that irrigation with povidone iodine is statistically more efficient in biofilm prevention of almost all examined bacteria compared to irrigation with octenidine dihydrochloride in all groups of implants. There was not found any statistical significance in prevention of Staphylococcus aureus biofilm when irrigating with povidone iodine compared to octenidine dihydrochloride in all groups of implants, and also in biofilm prevention of Ralsotnia pickettii in Group 2. According to results of this research, it is recommended to use micro-textured implants and to irrigate them with povidone iodine or mixture of povidone iodine and two antibiotics (cefuroxime and gentamycin) prior the implementation, in order to prevent biofilm formation which is most probable cause of postoperative complications after implant surgery.</p>