Magister Chirurgiae Dentium (MChD) / Wound healing is a complex process characterised by the repair and reconstitution of lost or damaged tissue. By the mid 1990s, several methods were proposed to enhance wound healing of surgical sites by introducing high concentrations of human platelets to these areas. In the early 21st century, Choukroun et al (2006b) introduced a new type of platelet concentrate that was devoid of any additives, and required no specialised equipment for its production. This concentrate was termed Platelet-rich fibrin (PRF) and although various aspects of this biomaterial had been studied, very little is currently known about its storage properties. Aim: To determine whether storage time had a significant effect on the platelet concentration of Choukroun’s PRF Method: A total of 30 patients were enrolled into the study. Three blood samples of 10ml each were drawn from each patient. Two of the blood samples (Group A and Group B) were centrifuged to form PRF. The third sample was used to measure the baseline blood platelet concentration and was therefore not centrifuged. After PRF had formed in both test groups, it was removed from the test tubes at 2 different times i.e. immediately after centrifuge (Group A) or after 60 min of storage in the blood collecting tube (Group B). The remaining blood was then tested for platelet concentration and compared to each other and the baseline reading. Results: 14 males and 16 females participated in the study (average age 41.7 years). A mean blood platelet concentration of 282.8 ± 58.3 × 109/L was recorded for the baseline reading. Group A had a mean blood platelet concentration 7.9 ± 3.03 × 109/L. Group B had a mean blood platelet concentration of 4.0 ± 1.93 × 109/L. A statistically significant difference was seen between Groups A and B (p < 0.0001). Conclusions: Storage time has a significant effect of the platelet concentration of PRF. If stored over a period of 60 min, the platelet concentration of PRF increases. Further research is required to determine whether this finding is clinically significant.

Background: Current research has demonstrated that aspirin and fish oil (EFA) increase plasma levels of specialized pro-resolution molecules (SPMs). This study investigates their effects on SPM precursor pools in platelet rich fibrin (PRF). Methods: Twenty healthy volunteers were randomly assigned to take aspirin; EFA or aspirin and EFA. Four hours later, SPM precursor levels were quantified using combined Liquid Chromatography tandem mass spectrometry. The differences between the groups: Aspirin (yes or no), EFA (yes or no), were analyzed by ANCOVA, testing for group differences after covarying out the baseline value. Results: There were 4 significant interactions, 1 with an aspirin effect, 2 with an EFA effect, and 64 with no difference between the groups. The significant interaction effect was found for the following lipidome: LPE(20:4), LPI(16:1), LPI(18:1), and LPI(20:3). Aspirin decreased the LPG(16:4) levels, and EFA decreased the LPE(22:5) and PG(16:0/18:0) lipidomes. Conclusions: Some SPM precursor pools in PRF were increased following supplementation.

Magister Chirurgiae Dentium - MChD (Oral Medicine and Periodontics) / In recent years, the development and use of autologous platelet rich concentrates (PC's) has gained traction within the rapidly progressive, multidisciplinary field of regenerative medicine. A PC subtype, marketed as advanced platelet rich fibrin (A- PRF), is a recent advancement of the original PRF protocol and promoted as a "blood concentrate" containing platelets, leukocytes, circulating stem cells and endothelial cells. A-PRF in the form of membranes, plugs, or even shredded particulates are increasingly being used as surgical adjuncts in areas of previous infection or left exposed within the microbial rich oral environment. Although recent literature has noted the biologic benefits of this material within the context of wound healing and regeneration, the antimicrobial potential of APRF has remained unexplored. The aim of this investigation is to determine if A-PRF displays antimicrobial activity against microbes of the oral cavity with a null hypothesis that its activity is no different to a clot of unprocessed venous blood. Methodology: A-PRF and whole blood samples were obtained from consenting individuals and utilised to conduct an in-vitro agar disk diffusion investigation to determine their antimicrobial activity. Standardised samples of A-PRF, unprocessed clotted blood and 0.2% chlorhexidine gluconate (CHX) were tested against organisms cultured from fresh oral rinse samples and pure cultures of candida albicans, streptococcus mutans, staphylococcus aureus and enterococcus faecalis. The antimicrobial activity was assessed in accordance to the established principles of the agar disk diffusion method and measurement of inhibition zones. Results: A-PRF displayed antimicrobial activity against all of the individual organisms tested within this study following a 24 hour incubation period. However, no significant differences were noted between A-PRF and a natural clot of blood when tested against cultures of the oral rinse sample. Finally, the antimicrobial activity of A-PRF is significantly inferior to an equal volume of the CHX preparation. Conclusion: Although A-PRF displays antimicrobial activity; its strength, spectrum and biologic activity within a polymicrobial environment requires further investigation.

Orientador: Daniela Leal Zandim-Barcelos / Resumo: A fibrina rica em plaquetas e leucócitos (L-PRF) é um derivado plaquetário autógeno capaz de liberar citocinas e fatores de crescimento favoráveis ao reparo tecidual. Por esta razão a L-PRF vem sendo utilizada em diversos procedimentos odontológicos. Uma das aplicabilidades clínicas da L-PRF é em procedimentos de levantamento do seio maxilar, uma técnica já consagrada na odontologia que permite a colocação de implantes dentários em região posterior de maxilas atróficas. Para avaliar a efetividade do uso da L-PRF, dois estudos clínicos independentes foram realizados utilizando a L-PRF em seios maxilares. Um deles teve o propósito de avaliar a influência da L-PRF na regeneração óssea quando associada ao osso mineral bovino desproteinizado (OBD) em procedimentos de elevação do assoalho do seio maxilar, e o outro teve o propósito de avaliar a efetividade da L-PRF no reparo de membranas de Schneider acidentalmente perfuradas durante o procedimento de levantamento do seio maxilar. Para isso, o primeiro trabalho foi um estudo clínico randomizado controlado envolvendo 19 pacientes com edentulismo na região posterior de maxila. De forma aleatória, 24 seios maxilares destes 19 pacientes foram distribuídos entre os grupos teste e controle. O grupo teste abordou 12 seios maxilares que foram enxertados com OBD associado à L-PRF, já o grupo controle abordou outros 12 seios maxilares enxertados apenas com OBD. Após 8 meses de reparo, uma biópsia foi obtida por meio de broca trefina no mesmo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Platelet and leukocyte-rich fibrin (L-PRF) is an autogenous platelet derivative capable of releasing cytokines and growth factors favorable to tissue repair. For this reason, LPRF has been used in several dental procedures. One of the clinical applicabilities of L-PRF is in maxillary sinus lifting procedures, a technique already established in dentistry that allows the placement of dental implants in the posterior region of atrophic jaws. To assess the effectiveness of using L-PRF, two independent clinical studies were conducted using L-PRF in maxillary sinuses. One of them had the purpose of evaluating the influence of L-PRF in bone regeneration when associated with deproteinized bovine mineral bone (DBB) in maxillary sinus floor elevation procedures, and the other had the purpose of evaluating the effectiveness of L-PRF in the repair of Schneider membranes accidentally perforated during the maxillary sinus lifting procedure. For this, the first study was a randomized controlled clinical study involving 19 patients with edentulism in the posterior region of the maxilla. At random, 24 maxillary sinuses of these 19 patients were distributed between the test and control groups. The test group involved 12 maxillary sinuses that were grafted with DBB associated with L-PRF, whereas the control group addressed 12 other maxillary sinuses grafted only with DBB. After 8 months of repair, a biopsy was obtained using a drill bit on the same axis of insertion of the implants. The biopsie... (Complete abstract click electronic access below) / Mestre

Em procedimentos de regeneração óssea guiada (ROG) as membranas de colágeno são os materiais mais utilizados como barreira; porém, sua tendência ao colapso faz indispensável a utilização de materiais de suporte. Para este propósito, os xenoenxertos são substitutos ósseos considerados padrão-ouro, embora apresentem um período longo de reabsorção que impede grande formação do osso. Em contrapartida o ?-fosfato tricálcico (?-TCP) permite boa formação do osso, mas é reabsorvido rapidamente e fracassa quando precisa dar suporte à membrana. O alendronato, um bisfosfonato nitrogenado, é uma droga antirreabsortiva para o tratamento da osteoporose e outras doenças ósseas porque inibe a função dos osteoclastos. O plasma rico em fibrina (PRF) é um concentrado de fibrina sem adição de químicos que consegue estimular processos de cicatrização pelos fatores que fazem parte de sua composição. Neste estudo qualitativo de ROG em defeitos de 5 mm no osso parietal de ratos foi avaliado: 1) o efeito na formação óssea da administração local de 1g/ml de alendronato sódico adicionado a xenoenxerto porcino e a ?-TCP; 2) a adição local de alendronato e PRF a ?-TCP na possibilidade de diminuir a rápida reabsorção do material e impedir o colapso da membrana. Foram usados 100 ratos adultos Wistar distribuídos em 5 grupos (n=20): Xenoenxerto controle (XE-C); xenoenxerto adicionado com alendronato (XE-AL); ?-TCP controle (TCP-C); ?-TCP adicionado com alendronato (TCP-AL); e, ?-TCP adicionado com PRF (TCP-F). Em todos os grupos o enxerto foi coberto com membrana. Dois tempos de estudo de quatro e oito semanas foram considerados para cada grupo (n=10). Ao final de cada tempo, os animais foram sacrificados e as amostras foram fixadas, descalcificadas e processadas para seu estudo em microscopia de luz por meio de análise histológica, histoquímica TRAP e imuno-histoquímica para osteopontina (OPN). Os resultados mostraram maior formação do osso tanto para xenoenxerto como para ?-TCP quando foram adicionados com alendronato local, em ambos tempos de estudo. Nos grupos do ?-TCP a adição de alendronato local permitiu diminuir a reabsorção dos grânulos, melhorando o suporte à membrana ao final dos tempos de estudo; no entanto, no grupo do PRF a reabsorção foi maior e teve pouca formação de osso, provocando colapso da membrana. Adicionalmente, regiões de osso primário subjacentes à membrana de colágeno foram observadas em todos os grupos. / Collagen membranes are the most used materials as a barrier in guided bone regeneration (GBR) procedures; however, its tendency to collapse makes indispensable the use of support materials. For this purpose, xenografts, which are bone substitutes, although they have a long period of resorption that prevents large bone formation, are still considered the gold standard support material. In contrast, tricalcium ?-phosphate (?-TCP) allows good bone formation, but is rapidly reabsorbed and fails when it needs to support the membrane. Alendronate, a nitrogenated bisphosphonate, is an anti-resorptive drug for treatment of osteoporosis and other bone diseases because it inhibits the function of osteoclasts. Fibrin-rich plasma (FRP) is a fibrin concentrate with no added chemicals that can stimulate healing processes by the factors that are part of its composition. In this qualitative study of ROG in 5 mm defects in the rat parietal bone, was evaluated: 1) the effect on bone formation of local administration of 1g / ml sodium alendronate added to porcine xenograft and ?-TCP; 2) the local addition of alendronate and PRF to ?-TCP in the possibility of diminishing the rapid reabsorption of the material and preventing the collapse of the membrane. A 100 adult Wistar rats distributed in 5 groups was used (n = 20): Xenograft control (XE-C); xenograft added with alendronate (XE-AL); ?-TCP control (TCP-C); ?-TCP added with alendronate (TCP-AL); and, ?-TCP added with PRF (TCP-F). In all groups the graft was covered with membrane. Two study times of four and eight weeks were considered for each group (n = 10). At the end of each time, the animals were sacrificed and the samples were fixed, decalcified and processed for light microscopy by histological analysis, TRAP histochemistry and immunohistochemistry for osteopontin (OPN). Results showed higher bone formation for both xenograft and ?-TCP when added with local alendronate at both study times. In the ?-TCP groups the addition of local alendronate allowed to decrease grain resorption, improving membrane support at the end of the study times; however, in the PRF group the resorption was greater and had little bone formation, causing membrane collapse. In addition, primary bone formed in the underlying collagen membrane were observed in all groups.

<p>Ekstrakcija zuba je intervencija prilikom koje se zub vadi iz svog leži&scaron;ta u zubnoj alveoli. Rana koja nastaje kao posledica ove intervncije je takvog oblika da njene ivice nije moguće približiti jednu drugoj , te zarasta per secundam intentionem. Ekstrakcija zuba ima za posledicu mnogobrojne promene na tvrdim i mekim tkivima alveolarnog nastavka u periodu od nekoliko meseci do godinu dana nakon intervencije. Savremena stomatologija se i dalje intenzivno bavi proučavanjem procesa zarastanja ekstrakcione rane iz potrebe da se &scaron;to bolje razumeju promene u tkivu koje nastaju po gubitku zuba da bi se mogle prevenirati i/ili usmeriti tako da se omogući kasnija lak&scaron;a protetska rehabilitacija pacijenata. Mnoge studije su pokazale efikasnost faktora rasta u tokom procesa zaceljivanja tkiva.Opisan je veliki broj tehnika za pripremu autolognih krvnih preparata koji sadrže faktore rasta, ali su njihova praktična primena i efikasnost su dalje nejasni zato &scaron;to svaka od ovih metoda dovodi do izrade različitog produkta sa različitom biologijom i potencijalnim indikacijama za upotrebu. Ekstrakcije mandibularnog trećeg molara spadaju u jednu od najče&scaron;ćih intervencija sa kojom se u svom radu svakodnevno sreću oralni i maksilofacijalni hirurzi. Ova hirur&scaron;ka procedura je povezana za postoperativnim efektima koji u velikoj meri utiču na kvalitet života pacijenta kao &scaron;to su bol, trizmus, edem, infekcija i alveolitis. U literaturi postoje dokazi da aplikacija nekog od autolognog krvnog preparata sa visokim sadržajem faktora rasta u određenoj meri može da pobolj&scaron;a proces zarastanja tkiva i da umanji neželjene propratne pojave hirur&scaron;ke intervencije nakon ekstrakcije mandibularnog trećeg molara. Cilj ovog rada je bio da utvrdimo da li primena autolognih krvnih preparata sa koncentrovanim faktorima rasta ubrzava stvaranje ko&scaron;tanog tkiva u ekstrakcionoj rani, kao i da li utiče na učestalost pojave alveolitisa i pojavu aproksimalinih parodontalnih džepova na susednim zubima nakon hirur&scaron;ke ekstrakcije donjeg trećeg molara. Studija je sprovedena kao prospektivna klinička studija split-mouth dizajna. U studiju je bilo uključeno 30 pacijenata kod kojih je indikovana ekstrakcija oba mandibularna treća molara i kod kojih su ovi zubi bilateralno u približno istom položaju u odnosu na drugi donji molar. Nakon hirur&scaron;ke ekstrakcije u jednu alveolu je aplikovan preparat koncentrovanih faktora rasta. Kontrolnu grupu u istraživanju činilo je 30 zubnih alveola u koje nije aplikovan preparat koncentrovanih faktora rasta. U eksperimentalnu grupu spadalo je 30 alveola u koje su aplikovani preparati koncentrovanih faktora rasta nakon ekstrakcije zuba. Pacijentima je prvi obavezan kontrolni pregled zakazivan za 7 dana nakon intervencije, tokom koga su uklanjane suture, a vr&scaron;en je i klinički pregled rane i parodontolo&scaron;kom sondom je proveravana dubina parodontalnog džepa na distalnoj povr&scaron;ini drugog molara. Druga postoperativna kontrola je zakazivana 4 nedelje nakon intervencije, a treća nakon 8 nedelja i na ovim kontrolama je merena dubina parodontalnog džepa na distalnoj povr&scaron;ini drugog molara. Ispitanicima su napravljena tri CBCT snimka operisanih regija i to po sledećoj dinamici- prvi snimak neposredno nakon ekstrakcije zuba, drugi 4 nedelje i treći 8 nedelja po intervenciji. Svaki CBCT snimak je analiziran da bi se prikupili željeni podaci: zapremina &scaron;upljine alveole koja je ostala nakon ekstrakcije zuba i gustina novostvorenog ko&scaron;tanog tkiva, &scaron;to su parametri na osnovu kojih procenjujemo proces zarastanja ko&scaron;tanog tkiva nakon intervencije. Ova metodologija je originalna , obzirom da su do sada kori&scaron;ćene dvodimenzionalne radiografske metode snimanja sa ciljem praćenja ko&scaron;tanog zarastanja nakon ekstrakcije zuba manje precizne i pouzdane. Dobijenu podaci su obrađeni odgovarajućim matematičko-statističkim postupcima. Najznačajniji rezultati istraživanja su zatim tabelarno i grafički prikazani. Na osnovu dobijenih rezultata do&scaron;li smo do zaključka da iako primena koncentrovanih faktora rasta dovodi do intenziviranja procesa ko&scaron;tanog zarastanja i smanjenja dubine parodontalnog džepa na distalnoj povr&scaron;ini susednih zuba, ta razlika nije statistički značajna. Obzirom da ni u jednom slučaju nije do&scaron;lo do pojave alveolitisa, nismo mogli zaključiti na koji način primena koncentrovanih faktora rasta utiče na učestalost ove komplikacije.</p> / <p>Tooth extraction is an intervention during which a tooth is removed from its socket. A wound that remains after this is of specific size and shape and it heals per secundam intentionem. Where once was a tooth, in following months and years, a large number of changes in composition of hard and soft tissues occure. Haeling of extraction wound in still in focus of contemporary dentistry, since it is imperative to understand all tissue changes in order to prevent and/or gide them and enable prosthodontic rehabilitation of the patient. Many studies confirm a benefitial effect of growth factors douring wound healing. A large number of techniques is developed to prepare autologous blood concentrates containing growth factors, like platelet-rich fibrin (PRF) , but their aplicability and efficancy are still unclear because each of these methods results in product with different biology and physical characteristics, as well as different potential indications. Third mandibular molar extraction is one of the most frequent interventions that oral and maxillofacial surgeon face in their everyday clinical practice. This procedure is usually followed by postoperative effects affecting such as pain, trismus, edema, infection and alveolitis. In contemporary literature there is enough evidence to suport beneficial role of autologous blood preparations in wound healing, and some authors even sugest that they can reduce incidence of postextraction complications afther third molar surgery. The aim of this study was to determin weather concentrated growth factors have beneficial effect on bone healing after tooth extraction, as well as their effect on the incidence of alveolitis and do they reduce pocket depth on distal side of adjacent tooth. This study was conducted as prospective clinical split-mouth designed study. 30 patients with both mandibular third molars indicated for the extraction, in similar position, were included in the study. On the same day surgical removal of both mandibular molars was performed, and in one socket PRF was placed. Patients were scheduled for a check-up and suture removals on the 7th postoperative day. During this visit, as well as after 4 and after 8 weeks, depth of distal pocket of the second molar was measured. CBCT was made on the day of surgery, 4 and 8 weeks afther surgery. On these radiographs volume of the bone defect was measured as well as density of newly formed bone tissue in the socket. This is original methodology, while previous studies used two-dimensional radiography methods in order to evaluate bone healing after tooth extractions, with less precision and liability. We processed and analyzed gained data using appropriate mathematical-statistical methods. According to our data we concluded that application of PRF in the extraction socket improves bone healing and reduces depth of pocket on the adjacent teeth, although this effects are not statistically significant. In our study, alveolitis did not occur neither in control nor in the experimental group, so we could not conclude if the application of PRF has any effect on prevention of this complication.</p>