Biomimetic implant surface functionalization with liquid L-PRF products: in vitro study

Abstract Objective: Platelet-rich fibrin (PRF) clots and membranes are autologous blood concentrates widely used in oral surgical procedures; less is known, however, about the liquid formulations of such products. The aim of this in vitro study is to assess the behavior of different implant surfaces when in contact with two liquid leucocyte- and platelet-rich fibrin (L-PRF) products. Methods: Six commercial pure titanium discs, of 9.5 mm diameter and 1.5 mm thickness, were used. Three of these samples had a micro/nano-rough surface; three were machined. Three different protocols were tested. Protocols involved the immersion of the samples in (1) a platelets, lymphocytes, and fibrinogen liquid concentrate (PLyF) for 10 minutes, (2) an exudate obtained from L-PRF clots rich in fibronectin and vitronectin for 5 minutes, and (3) the fibronectin/vitronectin exudate for 2 minutes followed by immersion in the PLyF concentrate for further 8 minutes. After these treatments, the samples were fixed and observed using a scanning electron microscope (SEM). Results: Under microscopic observation, (1) the samples treated with the PLyF concentrate revealed a dense fibrin network in direct contact with the implant surface and a significant number of formed elements of blood; (2) in the samples treated with the fibronectin/vitronectin exudates, only a small number of white and red blood cells were detectable; and (3) in samples exposed to the combined treatment, there was an apparent increase in the thickness of the fibrin layer. When compared to the machined surface, the micro/nano-rough samples showed an overall increased retention of fibrin, leading to a thicker coating. Conclusions: Liquid L-PRF products promote the formation of a dense fibrin clot on micro/nano-rough implant surfaces in vitro. The adjunctive treatment of surfaces with the fibronectin/vitronectin exudate could provide support to contact of the fibrin with the surface, though it is not essential for the clot formation. Further studies are necessary to better elucidate the properties and benefits of liquid L-PRF products

Soft tissue management and prosthetic rehabilitation in a tongue cancer patient

One major challenge in treating head and neck oncologic patients is to achieve an acceptable recovery of physiologic functions compatible with the complete tumor excision. However, after tumor resection, some patients present a surgically altered anatomy incompatible with prosthetic rehabilitation, unless some soft tissue correction is carried out. The aim of the present study is to describe the overall mandibular prosthetic rehabilitation of a postoncologic patient focusing on the possibility of soft tissue correction as a part of the treatment. A 72-year-old woman, who undergone a hemiglossectomy for squamous cell carcinoma several years before, was referred to our department needing a new prosthesis. The patient presented partial mandibular edentulism, defects in tongue mobility, and a bridge of scar tissue connecting one side of the tongue to the alveolar ridge. A diode laser (980 nm) was used to remove the fibrous scar tissue. After reestablishing a proper vestibular depth and soft tissue morphology, two implants were placed in the interforaminal region of the mandible to support an overdenture

Immediate or delayed retrieval of the displaced third molar : A review

The displacement of a third molar is a rare occurrence, but it could lead to serious and/or life threatening complication. Aim of this review is to understand the most correlated causes of displacement and the possible solutions proposed in literature to avoid and solve this complication for maxillary and mandibular third molars at the appropriate time. A search for ?third molar displacement? was performed by using Pubmed database. Articles referred to soft tissues displacement, from 1957 to 2018, were included in the review. The references lists of all eligible articles were examined and additional studies were added to the review only if indexed on Pubmed. All the articles on maxillary sinus displacement and the dislocation of dental fragments or surgical equipment were excluded. From a total of 134 results, 68 articles were examined for satisfying inclusion criteria. 18 articles were excluded because not inherent with the topic; 19 articles on infratemporal space, 11 on sublingual space, 9 on submandibular space, 11 on lateral pharyngeal space displacement were considered congruent for the review and included. The displacement of the third molar in deeper tissues could be avoided by the use of proper surgical procedures and instrumentarium. If displacement occurs, and the operator could not reach the tooth in safe conditions, the patient should be immediately referred to a maxillo-facial surgeon, because of the possibility of further displacement or the onset of hazardous or potentially fatal infections in vital regions

The prevention of implant surface alterations in the treatment of reri-implantitis: comparison of three different mechanical and physical treatments

The surgical treatment of peri-implantitis is currently based on the removal of biofilms from the implant surface by primary means of mechanical and physical treatments. However, such approaches often determine some alterations of the implant surface with detrimental effects on re-osseointegration. This study aims to evaluate the effects of four different mechanical and physical treatments on titanium samples with moderately rough surface. Air powder abrasion (AP) with glycine powder, a titanium brush (TB) and a diode laser at 3 W (L3) and 4 W (L4) were tested. Surface morphology, roughness and chemical composition were then assessed by scanning electron microscope (SEM), white light interferometer and X-ray photoelectron spectroscopy (XPS), respectively. The microscopic analysis revealed significant alterations in surface morphology on TB samples, while AP and L3 had only a minor or null impact. L4 samples revealed signs of overheating due to the excessive power. Nevertheless, the overall roughness of the samples was not significantly altered in terms of roughness parameters. Similarly, surface chemical composition was not significantly affected by the treatments. Among the treatments tested in this study, air powder abrasion with glycine powder and 3 W diode laser had the lowest impact on surface physicochemical properties.

Postextractive alveolar ridge preservation using L-PRF: clinical and histological evaluation

Leukocyte- and platelet-rich fibrin (L-PRF) is an autologous platelet concentrate rich in growth factors and plasma proteins, obtained by centrifugation of patient whole blood, and widely used in oral surgery. This report describes a case of alveolar ridge preservation with L-PRF membranes. Postextractive alveolar healing was then assessed through a histologic and histomorphometric analysis. A patient requiring tooth extraction and subsequent implant rehabilitation was treated with simple extraction and socket filling with L-PRF membranes. Implant placement was performed at 3 months, and a bone biopsy was obtained for histomorphometric analysis. Histological examination of the grafted sites showed that the use of L-PRF could achieve good results in terms of bone dimension and quality and soft tissue healing. The results of this study support the use of L-PRF membranes to preserve hard and soft tissues after tooth extraction

Platelet rich fibrin (PRF) and its related products: biomolecular characterization of the liquid fibrinogen

Liquid fibrinogen is an injectable platelet concentrate rich in platelets, leukocytes, and fibrinogen obtained by blood centrifugation. The aim of this study was to analyze the release of different growth factors in the liquid fibrinogen at different times and to assess possible correlations between growth factors and cell counts. The concentration of transforming growth factor beta 1 (TGF-β1), platelet-derived growth factor-AB (PDGF-AB), platelet-derived growth factor-BB (PDGF-BB), bone morphogenetic protein 2 (BMP-2), fibroblast growth factor 2 (FGF-2) and vascular endothelial growth factor (VEGF) released by liquid fibrinogen were examined with ELISA at three time points (T0, time of collection; T7, 7 days; T14, 14 days). The cellular content of the liquid fibrinogen and whole blood was also calculated for each volunteer. A mean accumulation of platelets of almost 1.5-fold in liquid fibrinogen compared to whole blood samples was found. An increase of TGF-β1, PDGF-AB, FGF-2, and VEGF levels was detected at T7. At T14, the level of TGF-β1 returned to T0 level; PDGF-AB amount remained high; the levels of FGF-2 and VEGF decreased with respect to T7, but remained higher than the T0 levels; PDGF-BB was high at all time points; BMP-2 level was low and remained constant at all time points. TGF-β1, PDGF-AB, and PDGF-BB showed a correlation with platelet amount, whereas BMP-2, FGF-2, and VEGF showed a mild correlation with platelet amount. Due to the high concentration of platelets, liquid fibrinogen does contain important growth factors for the regeneration of both soft and hard tissue. The centrifugation protocol tested in this study provides a valid solution to stimulate wound healing in oral and periodontal surgery

Antibacterial Activity and Impact of Different Antiseptics on Biofilm-Contaminated Implant Surfaces

Several antiseptic agents have been proposed for the treatment of peri-implantitis as a complementary therapeutic strategy in addition to mechanical devices. The aim of this study was to compare six different antiseptics, as well as alternative formulations of the same chemical agent, with respect to their decontamination efficacy and impact on chemical properties of the implant surface. Titanium disks with a micro-rough surface, previously contaminated with Porphyromonas gingivalis and Streptococcus mutans biofilms, were treated for 2 min with different antiseptics (liquid sodium hypochlorite 5.25%, gel sodium hypochlorite 5.25%, liquid chlorhexidine 0.2%, gel chlorhexidine 1%, gel citric acid 40%, and gel orthophosphoric acid 37%) or sterile saline solution (control) and their antibacterial activity as well as their ability to remove biofilm were assessed by viable bacterial count and scanning electron microscopy, respectively. Spectroscopic analysis was also performed on non-contaminated disks after exposure to the antiseptics, in order to detect any change in the elemental composition of the titanium surface. All the antimicrobial formulations examined were effective against P. gingivalis and S. mutans biofilms. SEM analysis revealed however that liquid sodium hypochlorite 5.25% was more effective in dissolving biofilm residues. Spectroscopic analysis detected traces of the antiseptics, probably due to insufficient rinsing of the titanium surfaces. In conclusion, since gel formulations of these antiseptic agents possessed a similar antibacterial activity to the liquid formulations, these may be proposed as alternative treatments given their properties to avoid overflows and increase contact time without significant side effects on the bone

Assessment of corneal alterations by confocal microscopy in vernal keratoconjunctivitis

Abstract Background: Vernal keratoconjunctivitis (VKC) is a bilateral chronic, seasonally exacerbated inflammation of the ocular surface that especially affects male children and young boys. Aim: To evaluate the corneal microscopic features of patients affected by VKC and to assess whether some corneal changes were associated with specific ocular symptoms and/or signs. Methods: 20 children aged between 4 and 14 years were enrolled. All patients underwent corneal confocal microscopy by Confoscan CS3 (Nidek). 350 images of the central cornea of each eye were obtained with a ×40 noncontact lens 3,5 micron gap in automode. Results: Some alterations of the sub-basal and stromal corneal nerves were detected. These alterations were more evident in patients with higher severity of photophobia. On the other hand, there were scarce other signs of the anterior segment of the eye. Conclusions: Our preliminary findings show that there is another group of patients affected by VKC, characterized by an intense photophobia caused by corneal damage and without other significant ocular alterations. Therefore confocal microscopy may be useful for an early identification of corneal alterations before the onset of severe ocular symptoms and to set an appropriate therapeutic management

Efficacy of Topical Treatments for the Management of Symptomatic Oral Lichen Planus: A Systematic Review

Oral lichen planus (OLP) is a chronic mucosal inflammatory disease associated with T-cell-mediated immunological dysfunction. Symptomatic OLP is a painful condition, and complete healing is often not achieved. The aim of this systematic review was to assess the effectiveness of topical drugs, medications, and other interventions compared to placebo or to other treatments in pain reduction and clinical resolution in adult patients with symptomatic OLP. A detailed electronic literature search was performed through the MEDLINE (PubMed) database between 1 January 2005 and 30 September 2022. Eligible studies were selected based on the inclusion criteria, and a quality assessment was conducted. From 649 titles, 121 articles were selected as abstracts, 75 papers were assessed as full text, along with 15 other papers obtained through a manual search. A total of 15 RCTs were finally included in the review process. Because of the significant heterogeneity in the study design of the included studies, no meta-analysis of the data could be performed. Topical corticosteroids represent the first-line treatment in the management of symptomatic OLP due to their efficacy and minimal adverse effects. Calcineurin inhibitors seem to be equally effective and are indicated in recalcitrant cases, extensive lesions, patients susceptible to oral candidiasis, or cases unresponsive to corticosteroids. Other treatments, such as aloe vera, chamomile, isotretinoin, ozone, and laser therapy, could be beneficial as adjunct therapies in association with first-line treatments