Breast implant capsular contracture (CC) formation is a significant clinical complication post augmentation/reconstruction, which often necessitates re-operation. CC, which occurs in over half of patients post augmentation, is the formation of a fibrous internal capsule which constricts around the prosthesis leading to firmness, deformity and pain. The pathoetiology of CC is poorly understood with minimal understanding of the triggers, signalling pathways or dysregulated genes implicated in its formation. Therefore, the first aim of the present thesis was to investigate biomarkers implicated in CC formation, through whole genome microarray, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) on capsule samples ranging from normal capsules (Baker Grade 1) to severely contracted capsules (Baker Grade 4). After targeted enrichment analysis, microarray identified 6 genes which were significantly dysregulated in contracted capsules. After further genomic and proteomic validation, two potential diagnostic, prognostic or therapeutic biomarkers for CC, interleukin 8 (IL8) and tissue inhibitor of metalloproteinase 4 (TIMP 4), were identified as being significantly dysregulated in CC. However, the role of each of the multiple cell types which populate a contracted capsule has yet to be determined. Therefore, the role of capsular fibroblasts was investigated using immunocytochemistry, qRT-PCR, cytokine arrays and a fibroblast populated 3D collagen matrix. IL8 and TIMP were investigated, in addition to other pro-fibrotic and pro-inflammation related candidates, to identify the role of breast capsule fibroblasts in CC formation. Normal breast fibroblast populated collagen matrices were significantly more contracted after supplementation with contracted-capsule fibroblast conditioned media, in comparison to normal growth media. It was discovered that breast-derived fibroblasts were potentially instigating and/or perpetuating CC through the transformation of normal breast fibroblasts into contracted capsule fibroblast like cells, via a paracrine signalling mechanism. The results of this work on capsular fibroblasts, and the previous work on capsular tissue, increased our understanding of the cell types and signalling molecules which are dysregulated leading to CC formation. Therefore, a novel silicone implant surface potentially capable of averting CC formation could be fabricated. Acellular dermal matrix (ADM) has been used as an adjunct in breast implant augmentation/reconstruction resulting in reduced rates of CC formation. Therefore, the micro and nanoscale topography of ADM was reproduced in a silicone surface, through a novel fabrication technique utilising comprehensive characterisation of ADM with atomic force microscopy (AFM), maskless grayscale photolithography, modified deep reactive ion etching (DRIE) and replica moulding. The features of ADM were successfully re-created in silicone to within 5 nm (Sa) and 655 nm (Sz), at a length scale of 90x90 µm2. Biological evaluation revealed that ADM PDMS surfaces promoted cell adhesion, proliferation and survival when compared to commercially available implant surfaces while cell adhesion regulating genes were upregulated and pro-inflammatory/pro-fibrotic related genes were downregulated. A reduced inflammatory cytokine response was also observed. This study demonstrates that biomimetic prosthetic implant surfaces might significantly attenuate the acute in vitro foreign body reaction to silicone. In conclusion, the results of the present thesis have enhanced our knowledge and understanding of the pathological cellular and molecular mechanisms leading to CC, in addition to the design and development of a novel, biomimetic implant surface that is potentially capable of averting the identified pathological processes in vivo.

As the survival rate increases, the importance of quality of life post-cancer is increasing. This, in conjunction with genetic screening, has increase the number of breast reconstructions 36%. The most common complication causing revision of reconstructive surgery is the formation of a dense scar capsule around the silicone implant called capsular contracture. Nearly all patients will experience this complication, though with different degrees of response, ranging from moderate scarring to major disfigurement and pain at the implant site. Presently, there is no way to predict the degree of contraction capsule formation that individual patients will suffer prospectively, nor is there clinical approach to preventing this complication. Patient information and tissue was collected in a uniform manner to address these lingering problems. Clinical data was used to construct a predictive model which can accurately predict capsular contracture severity in breast reconstruction patients. Histological analysis demonstrated differences in structure and cell composition between different capsule severities. Of particular note, a new region was described which could serve as the communication interface between innate immune cells and fibroblasts. RNA-seq analysis identified 1029 significantly dysregulated genes in severe capsules. Pathway enrichment was then performed which highlights IL4/13 signaling, extracellular matrix organization, antigen presentation, and interferon signaling as importantly dysregulated pathways. These RNA results were also compared to various clinical and histological measurements to evaluate novel correlations. PVT-1, a long non-coding RNA associated with cancer, was strongly correlated to capsules formed after cancer removal. This suggests cancerous transformations of cell types that remain after the tumor is removed. Furthermore, transgelin and caspase 7 correlated to myofibroblasts density, suggesting an abnormal fibroblasts that are resistant to cell death and may have enhanced contractile abilities. Capsule formation is a complex process however, with well controlled clinical models quantitative differences can be found. These results serve as stepping stone for the field to move beyond retrospective clinical trials and pursue treatments and preventative measures. / Ph. D. / As the survival rate increases, the importance of quality of life post-cancer is increasing. This, in conjunction with genetic screening, has increase the number of breast reconstructions 36%. The most common complication causing revision of reconstructive surgery is the formation of a dense scar capsule around the silicone implant called capsular contracture. Nearly all patients will experience this complication, though with different degrees of response, ranging from moderate scarring to major disfigurement and pain at the implant site. Presently, there is no way to predict the degree of contraction capsule formation that individual patients will suffer prospectively, nor is there clinical approach to preventing this complication. Patient information and tissue was collected in a uniform manner to address these lingering problems. Clinical data was used to construct a predictive model which can accurately predict capsular contracture severity in breast reconstruction patients. Histological analysis demonstrated differences in structure and cell composition between different capsule severities. Of particular note, a new region was described which could serve as the communication interface between innate immune cells and fibroblasts. RNA-seq analysis identified 1029 significantly dysregulated genes in severe capsules. Pathway enrichment was then performed which highlights IL4/13 signaling, extracellular matrix organization, antigen presentation, and interferon signaling as importantly dysregulated pathways. These RNA results were also compared to various clinical and histological measurements to evaluate novel correlations. PVT-1, a long non-coding RNA associated with cancer, was strongly correlated to capsules formed after cancer removal. This suggests cancerous transformations of cell types that remain after the tumor is removed. Furthermore, transgelin and caspase 7 correlated to myofibroblasts density, suggesting an abnormal fibroblasts that are resistant to cell death and may have enhanced contractile abilities. Capsule formation is a complex process however, with well controlled clinical models quantitative differences can be found. These results serve as stepping stone for the field to move beyond retrospective clinical trials and pursue treatments and preventative measures.

No description available.

La reconstruction en deux étapes par expanseur et implant est la technique la plus répandue pour la reconstruction mammmaire post mastectomie. La formation d’une capsule périprothétique est une réponse physiologique universelle à tout corps étranger présent dans le corps humain; par contre, la formation d’une capsule pathologique mène souvent à des complications et par conséquent à des résultats esthétiques sous-optimaux. Le microscope électronique à balayage (MEB) est un outil puissant qui permet d’effectuer une évaluation sans pareille de la topographie ultrastructurelle de spécimens. Le premier objectif de cette thèse est de comparer le MEB conventionnel (Hi-Vac) à une technologie plus récente, soit le MEB environnemental (ESEM), afin de déterminer si cette dernière mène à une évaluation supérieure des tissus capsulaires du sein. Le deuxième objectif est d‘appliquer la modalité de MEB supérieure et d’étudier les modifications ultrastructurelles des capsules périprothétiques chez les femmes subissant différents protocoles d’expansion de tissus dans le contexte de reconstruction mammaire prothétique. Deux études prospectives ont été réalisées afin de répondre à nos objectifs de recherche. Dix patientes ont été incluses dans la première, et 48 dans la seconde. La modalité Hi-Vac s’est avérée supérieure pour l’analyse compréhensive de tissus capsulaires mammaires. En employant le mode Hi-Vac dans notre protocole de recherche établi, un relief 3-D plus prononcé à été observé autour des expanseurs BIOCELL® dans le groupe d’approche d’intervention retardée (6 semaines). Des changements significatifs n’ont pas été observés au niveau des capsules SILTEX® dans les groupes d’approche d’intervention précoce (2 semaines) ni retardée. / Two-stage implant-based (expander to implant) breast reconstruction is the most frequently applied technique following total mastectomy. While the periprosthetic capsule is a normal physiologic response to any foreign body, pathological capsule formation often leads complications and suboptimal aesthetic results. The scanning electron microscope (SEM) is a powerful tool that offers unparalleled assessment of capsule ultrastructural topography. The first research aim was to compare conventional high-vacuum (Hi-Vac) SEM with newer environmental scanning electron microscopy (ESEM) technology to determine whether the latter offers superior assessment of breast capsular tissue. The second aim was to apply the most optimal SEM mode to study periprosthetic capsule ultrastructural modifications in women undergoing differing expansion protocols during the first stage of implant-based reconstruction. Ten patients were prospectively included in the first study and 48 prospectively included into the second. Conventional Hi-Vac mode was deemed superior for the comprehensive analysis of breast capsular tissue. Using Hi-Vac mode within the established study protocol, a more pronounced capsular 3-D relief was observed around BIOCELL® expanders when the first postoperative saline inflation took place at 6 weeks following expander insertion (delayed approach). No significant changes were observed with SILTEX® expander capsules in both early (2 weeks) and delayed approach groups.

Avec près de 25 000 cas en 2015, le cancer du sein est de loin le cancer le plus fréquent chez les femmes canadiennes. En termes de mortalité, le cancer du sein se place au deuxième rang (13,8%), derrière le cancer du poumon (26,5%). Suite au diagnostic, 70% des femmes avec un cancer de stade avancé et 30% des femmes avec cancer précoce choisiront de subir une mastectomie totale. Plusieurs options de reconstructions mammaires sont ensuite offertes. Plus de 70% des reconstructions se feront par la mise en place d’implants mammaires (plutôt que par reconstruction autologue utilisant les tissus de la patiente). Parmi les complications survenant après cette intervention, la contracture capsulaire en est une des plus fréquente. La contracture capsulaire se définit comme la contraction anormale de la capsule fibreuse se formant autour des implants mammaires, pouvant causer des douleurs en plus d’un mauvais résultat sur le plan esthétique. Les études cliniques ont démontré un risque accru de développer une contracture capsulaire chez les femmes ayant du suivre un protocole de radiothérapie. Si plusieurs études ont cherché à démontré l’influence des radiations sur l’histologie et l’immunologie du tissu capsulaire, aucune étude ne s’était intéressée à leur effet sur l’ultrastructure capsulaire. Notre équipe a récemment démontré que l’ultrastructure capsulaire dépendait de plusieurs facteurs, notamment de la texture prothétique et du délai de reconstruction. L’objectif de ce mémoire était de décrire l’impact de la radiothérapie sur l’ultrastructure capsulaire en comparant des capsules irradiées et non-irradiées en utilisant la microscopie éléctronique à balayage. Nous avons observé, chez les échantillons issus de capsules irradiés, une perte de relief au niveau de l’interface prothèse-capsule par rapport au échantillons non irradiés. Nous avons aussi démontré que cette caractéristique ultrastructurale est associée à la présence de contracture capsulaire. Enfin, ces effets néfastes de la radiothérapie semblent altérer la capacité de la capsule à adhérer à la prothèse mammaire. En conclusion, mon projet de maîtrise aura permis de décrire pour la première fois l’impact de la radiothérapie sur l’ultrastructure des capsules périprothétiques. Bien que nos résultats ne nous permettent pas d’expliquer de façon certaine le lien potentiel avec l’évolution vers un état de contracture capsulaire, ils laissent croire que cela serait associé avec un diminution de la stabilité de la capsule sur son implant, facteur auparavant évoqué comme ayant une rôle protecteur sur la contracture capsulaire. / With around 25,000 cases in 2015, breast cancer is the most common cancer among Canadian women. In term of mortality, breast cancer is second (13.8%), only behind lung cancer (26.5%). As part of the therapeutic approaches, around 70% and 30% of women with advanced and early breast cancer (respectively) will chose to have a total mastectomy. Following a mastectomy, few options of breast reconstruction are offered to the patients. More than 70% of breast reconstructions are implant-based. Among the complications following this surgery, capsular contracture (CC) is one of the most common. CC is defined as the abnormal, and sometimes painful, contraction of the fibrous capsule that normally grows aroung breast implants, resulting in a aesthetic failure and associated with a higher surgical revision rate. Many studies have demonstrated that the incidence of CC was higher among women who had undergone radiotherapy prior to their implant-based breast breast reconstruction procedure. Most of published studies focus on the influence of radiotherapy on capsular tissue at the immune-histological level but no study has described its influence on capsular architecture. As our team recently demonstrated that capsular ultrastructure is influenced by many factors (prosthetic texture, expansion timing). The main purpose was to describe the impact of radiotherapy on periprosthetic capsule ultrastructural features by comparing irradiated and non-irradiated capsules using scanning electron microscopy (SEM). We observed a significant loss of tridimensional texture at the implant-capsule interface in irradiated capsular samples. This feature was also found to be associated with CC. Finally, our results tend to show that radiotherapy impaires the stability of capsules by preventing them to grow withing their surrounding implant texure. In conclusion, the present research project offers the first description of the capsular response following exposiong to radiations. Even though our results do not allow us to conlude to a clear relation between loss of capsular architecture and a higher risk of CC, we think that the impairement of capsular stability might be part of the answer

<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>