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This systematic review (SR) aimed to evaluate the antimicrobial potential of different types of platelet-rich fibrin (PRF) often used in regenerative treatments. An electronic search was performed in four databases and in Gray literature for articles published until January, 2023. The eligibility criteria comprised in vitro studies that evaluated the antimicrobial effect of different types of PRF. For the analysis of the risk of bias within studies, the modified OHAT (Office of Health Assessment and Translation) tool was used. For the evaluation of the results, a qualitative critical analysis was carried out in the synthesis of the results of the primary studies. Sixteen studies published between 2013 and 2021 were included in this SR. The antimicrobial effects of PRF variations (PRF, injectable PRF [I-PRF], PRF with silver nanoparticles [agNP-PRF], and horizontal PRF [H-PRF]), were analyzed against 16 types of bacteria from the oral, periodontal, and endodontic environments. All types of PRF showed significant antimicrobial action, with the antibacterial efficacy being more expressive than the fungal one. The I-PRF, H-PRF, and agNP-PRF subtypes improve antimicrobial activity. According to the OHAT analysis, no study was classified as having a high risk of bias. Evidence suggests that PRF variations have significant antimicrobial activity, with bacterial action being greater than fungal. Evolutions such as I-PRF, H-PRF, and agNP-PRF improve antimicrobial activity. Future studies analyzing the clinical effect of these platelets are fundamental. This SR was registered in INPLASY under number INPLASY202340016.

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This study evaluated the potential of Leukocyte-platelet-rich fibrin (L-PRF; fixed angle centrifugation protocol), Advanced-platelet-rich fibrin (A-PRF; low-speed fixed angle centrifugation protocol), and Horizontal-platelet-rich fibrin (H-PRF; horizontal centrifugation protocol) in bone neoformation in critical size defects (CSDs) in rat calvaria. Thirty-two rats were divided into groups: Control (C), L-PRF, A-PRF, and H-PRF. 5 mm diameter CSDs were created in the animals' calvaria. Defects from group Control (C) were filled with blood clots, while defects from groups L-PRF, A-PRF, and H-PRF were filled with respective platelet-rich fibrin (PRF) membranes. L-PRF, A-PRF, and H-PRF were prepared from animal blood collection and specific centrifugation protocols. At 14 and 30 days, calcein (CA) and alizarin (AL) injections were performed, respectively. Animals were euthanized at 35 days. Microtomographic, laser confocal microscopy, and histomorphometric analyzes were performed. Data were statistically analyzed (ANOVA, Tukey, p < .05). L-PRF, A-PRF, and H-PRF groups showed higher values of bone volume (BV), newly formed bone area (NFBA), and precipitation of CA and AL than the C group (p < .05). The H-PRF group showed higher values of BV, number of trabeculae (Tb. N), NFBA, and higher precipitation of AL than the A-PRF and L-PRF groups (p < .05). Therefore, it can be concluded that: i) L-PRF, A-PRF, and H-PRF potentiate bone neoformation in CSDs in rat calvaria; ii) H-PRF demonstrated more biological potential for bone healing.

After tooth loss, the alveolar bone (which supports the teeth) undergoes a natural process called bone remodeling, which can lead to significant decreases in bone height and thickness over time. Faced with the need to replace missing teeth, especially when it comes to dental implants, the lack of supporting tissues can compromise their correct positioning, leading to negative impacts on the success and longevity of the treatment. Therefore, over the years, several materials and procedures have been proposed to preserve and regenerate oral tissues. Leukocyte-platelet-rich fibrin (L-PRF) consists of a membrane obtained by centrifuging the patient's blood in a fixed-angle centrifuge, allowing cells to be available to stimulate tissue regeneration directly at the place of action. Several reports demonstrate high potential in stimulating the formation of new tissues using L-PRF. In recent years, new protocols have been proposed to increase cell concentration and improve the regenerative potential of these membranes, changing the speed and time of centrifugation and introducing horizontal centrifugation. However, there still needs to be concrete evidence of the superiority of the new protocols in relation to the original protocol. In this study, we evaluated the healing of defects created in rat calvaria using platelet aggregates obtained through different centrifugation protocols. Within the limits of this study, it can be concluded that platelet aggregates improve bone healing, and horizontal centrifugation promotes more satisfactory results compared to fixed-angle protocols.

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Obter corretamente a Fibrina Rica em Plaquetas (PRF) depende da execução de cada etapa de maneira protocolada. Nesse sentido, no Laboratório Associado de Pesquisa Clínica (LPCO), da Faculdade de Odontologia da Universidade Federal Fluminense (FO-UFF) é utilizado o sistema IntraSpin® de centrifugação do sangue coletado, que caracteriza o segundo passo para preparo deste material autólogo. O objetivo do presente trabalho é realizar uma descrição prática do correto manuseio da Centrífuga IntraSpin para garantir a obtenção do PRF e sua efetiva aplicabilidade clínica.

Obtaining Platelet Rich Fibrin (PRF) correctly depends on the execution of each step in a protocol manner. In this sense, at the Associated Clinical Research Laboratory (LPCO), of the Faculty of Dentistry in the Federal Fluminense University (FO-UFF) the IntraSpin® centrifugation system is used in the collected blood, that characterizes the second step to prepare this autologous material. The objective of this present work is to make a practical description of the correct handling of the IntraSpin Centrifuge to guarantee the PRF's biocompatibility and its effective clinical applicability.

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The current study evaluated the healing of critical-size defects (CSD) created in rat calvaria treated with platelet concentrates produced by high-speed (Leukocyte- and Platelet-Rich Fibrin - L-PRF) and low-speed (Advanced Platelet-Rich Fibrin - A-PRF) protocols of centrifugation. Twenty-four rats were distributed into three groups: Control, L-PRF, and A-PRF. Five mm diameter CSD were created on the animals' calvaria. The defects of the L-PRF and A-PRF groups were filled with 0.01 ml of L-PRF and A-PRF, respectively. The control group defects were filled with a blood clot only. All animals were euthanized on the 35th postoperative day. Histomorphometric and microtomographic analyses were then performed. The L-PRF and A-PRF groups had significantly higher bone volume and neoformed bone area than those of the control group and lowered bone porosity values (p < .05). No significant differences were observed between A-PRF and L-PRF groups for the analyzed parameters. Therefore, it can be concluded that i) L-PRF and A-PRF potentiated the healing of CSD in rat calvaria; ii) high and low-speed centrifugation protocols did not produce PRF matrices with different biological impacts on the amount of bone neoformation.

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This study aimed to compare two beta-tricalcium phosphates with different particle sizes in human maxillary sinuses lifting. The immunolabeling of cells for RUNX2 and VEGF were performed to evaluate the osteoblast precursor cells and the vascular formation after 6 months of bone repair. Ten maxillary sinuses were grafted with autogenous bone graft (Group 1), 10 were grafted with ChronOs® (Group 2), and 10 were grafted with BETA-TCP® (Group 3). After 6 months of bone healing, biopsies were obtained to assess the new bone formed by histomorphometric and immunohistochemical evaluation for RUNX2 and VEGF. The mean bone formation for Group 1 was 51.4 ± 17.4%. Group 2 presented 45.5 ± 9.9%, and Group 3 conferred 35.4 ± 8.0% of new bone formation. The RUNX2 offered low for Groups 1 and 2 with high cellular activity for osteoblast in Group 3. The VEGF immunolabeling was moderate for Groups 1 and 2 and intense for Group 3. In conclusion, it was possible to show that the bone substitutes evaluated in the present study presented suitable outcomes for bone regeneration, being an alternative for the autogenous bone graft in maxillary sinus bone height reconstruction.

RESUMO

Sticky bone, a growth factor-enriched bone graft matrix, is a promising autologous material for bone tissue regeneration. However, its production is strongly dependent on manual handling steps. In this sense, a new device was developed to simplify the confection of the sticky bone, named Sticky Bone Preparation Device (SBPD®). The purpose of this pilot study was to investigate the suitability of the SBPD® to prepare biomaterials for bone regeneration with autologous platelet concentrates. The SBPD® allows the blending of particulate samples from synthetic, xenograft, or autogenous bone with autologous platelet concentrates, making it easy to use and avoiding the need of further manipulations for the combination of the materials. The protocol for the preparation of sticky bone samples using the SBPD® is described, and the resulting product is compared with hand-mixed SB preparations regarding in vitro parameters such as cell content and the ability to release growth factors and cytokines relevant to tissue regeneration. The entrapped cell content was estimated, and the ability to release biological mediators was assessed after 7 days of incubation in culture medium. Both preparations increased the leukocyte and platelet concentrations compared to whole-blood samples (p < 0.05), without significant differences between SB and SBPD®. SBPD® samples released several growth factors, including VEGF, FGFb, and PDGF, at concentrations physiologically equivalent to those released by SB preparations. Therefore, the use of SBPD® results in a similar product to the standard protocol, but with more straightforward and shorter preparation times and less manipulation. These preliminary results suggest this device as a suitable alternative for combining bone substitute materials with platelet concentrates for bone tissue regeneration.

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A extração dentária é um dos procedimentos mais frequentes em cirurgia oral e maxilofacial e está relacionada a mudanças fisiológicas no processo alveolar. Neste sentido, entre as principais complicações transoperatórias está a hemorragia, que ocorre geralmente devido a lesões de vasos sanguíneos presentes no alvéolo dentário onde se realizou a exodontia. Uma alternativa para se obter a hemostasia é a utilização da Fibrina Rica em Plaquetas (PRF), um concentrado leucoplaquetário, obtido através do sangue do paciente. A membrana obtida é rica em leucócitos, plaquetas e fatores de crescimento que promovem a modulação de células envolvidas no processo de cicatrização, favorecendo um melhor e mais rápido reparo das lesões cirúrgicas. Esta matriz de fibrina apresenta diversas utilidades para a odontologia, demonstrando bons resultados, além do baixo custo e fácil obtenção. O objetivo deste artigo é descrever a técnica de obtenção da PRF usada como agente hemostático após exodontia, orientando assim, sua reprodutibilidade e utilização.

Tooth extraction is one of the most frequent procedures in oral and maxillofacial surgery and is related to physiological changes in the alveolar process. In this sense, among the main transoperative complications is hemorrhage, which usually occurs through the dental alveolus, due to damage to the blood vessels where the extraction was performed. An alternative to obtain hemostasis is the use of Fibrin Rich in Platelets (PRF), which is a white platelet concentrate obtained from the patient's blood that undergoes a centrifugation step. The membrane obtained after this process is rich in leukocytes, platelets and growth factors that promote modulation of cells involved in the healing process, favoring a better and faster repair of surgical lesions. This fibrin matrix has several uses for dentistry, showing good results, in addition to being low cost and easy to obtain. The aim of this article is to describe the technique for obtaining Platelet-Rich Fibrin (PRF) used as a hemostatic after tooth socket extraction, thus allowing its reproducibility and use.

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This study aimed to evaluate the correlation between epidermal growth factor (EGF) and receptor (EGFR) levels in different clinical stages of dental implant rehabilitation and trace mucositis development's biological profile. Thirty-six participants from the Specialization in Implant Dentistry, Universidade Federal Fluminense, Brazil, were included in the study and underwent sample collection: inside the alveolar socket, immediately before implant placement (Group 1, n = 10); at the peri-implant crevicular fluid (PICF) during reopening (Group 2, n = 10); PICF from healthy peri-implant in function (Group 3, n = 8); and PICF from mucositis sites (Group 4, n = 18). Quantitative polymerase chain reaction (PCR) evaluated EGF/EGFR gene expression using the SYBR Green Master Mix detection system. The results showed that EGF expression in the peri-implant crevicular fluid was statistically different. There was a higher EGF expression for group C (peri-implant health) (p = 0.04) than for the other groups. Regarding EGFR, there was no statistical difference among the groups (p = 0.56). It was concluded that low levels of EGF gene expression in the peri-implant crevicular fluid are related to the development of peri-implant mucositis and the absence of mucosae sealing. There was no correlation between EGFR gene expression with health or mucositis.

RESUMO

Irrigant solutions are used to promote dentin-growth factors (GF) release for regenerative endodontics. This review aimed to evaluate the reports comparing the release of GFs using different root canal irrigant solutions. Eligible studies compared the in vitro GF release in human teeth after the use of at least two distinct solutions. A search was conducted on Pubmed, Scopus, Web of Science, and Lilacs on 11 August 2021. Risk of bias was assessed using SciRAP. Study characteristics and quantitative data were extracted, and meta-analyses were performed for the mean difference (95% confidence interval) of the release of transforming growth factors Beta 1 (TGF-ß1) by EDTA compared to other irrigants. Of sixteen eligible studies, eight were included in quantitative analysis. ELISA assays showed higher TGF-ß1 release from 10% EDTA compared to 10% citric acid (p < 0.00001). Immunogold assays showed higher levels of TGF-ß1 for 17% EDTA (p < 0.00001) compared to 10% citric acid. GRADE identified a low to very low certainty of evidence. These results point to an increased release of TGF-ß1 in dentin treated with EDTA. The high heterogeneity and very low certainty of the evidence demand further studies before EDTA indication as a better irrigant for regenerative endodontics. Registration: CRD42020160871 (PROSPERO).

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The present study aimed to evaluate the influence of manual torque (10 Ncm) versus clinical torque (30 Ncm), which is recommended by the manufacturer, on the total length of morse cone implant abutments. Twenty specimens were prepared and distributed into two groups: group 1 with ten analogs for morse cone type implant, and group 2 with ten morse type implants, size 4.3 × 15 cm. In each group, the distance between the implant platform to the top of the prosthetic abutment (abutment height) was measured and subjected to a torque of 10 Ncm. Then, the 30 Ncm torque was applied to the same abutment, and abutment height was measured. The distance between the top of the abutment and the implant/analog base was measured. In order to verify the clinical reproducibility of the experiment, comparisons between the abutment height of the analog at 10 Ncm and the implant at 30 Ncm were performed, showing a greater discrepancy in torque for the 10 Ncm analog (p < 0.05). In order to verify if the change in the laboratory protocol from 10 to 30 Ncm could minimize the differences in the height of the prosthetic abutments, the abutment height in groups 1 and 2 was compared with 30 Ncm, and no significant difference was observed (p > 0.05). The data indicated that the manual torque and the torque recommended by the manufacturer influence the total length of the prosthetic abutments of morse cone implants.