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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.

Aim The aim of this study was to analyze, by the aid of microbiological analysis and the field emission scanning electron microscopical (FE-SEM) analysis, the role of high-density polytetrafluoroethylene (d-PTFE) membranes in avoiding the microbial colonization of a nanocrystalline hydroxyapatite (nc-HA) bone graft and the involvement of this colonization in the healing process. Materials and methods Six patients underwent extraction of unrecoverable teeth, and a socket preservation technique was carried out with nc-HA synthetic bone graft and then covered with a d-PTFE membrane. After 28 days from surgery, FE-SEM analysis and BioTimer assay technique to assess the microbiological count of streptococci species were carried out. Data were collected and analyzed by the Student's t test (confidence interval: 95%). Results The mean amount of bacteria measured on the upper side of the membrane was 6.52 ± 0.50 CFU, while on the lower side, it was 6.59 ± 0.40 CFU. Significant differences were not found between the two sides of the membrane or between the different sectors (p > 0.05). The FE-SEM analysis revealed structured biofilms on both sides of the membrane: species of cocci, bacilli, and fusobacteria were recognizable in occasional settled vegetations. Conclusion Since the amount of bacteria found was low, the improved impermeability of the d-PTFE membrane permitted the healing process to proceed uneventful and without signs of infection or inflammation. Clinical relevance The infection of the graft site could lead to a failure of the socket preservation technique which could delay or compromise the rehabilitation following procedures. The use of d-PTFE can improve the bone regeneration thanks to its antimicrobial properties.

This article was published in volume 69, issue 1 of publishing year 2020, with the wrong Figure 1. The correct Figure 1 is the one included in this erratum.

The COVID-19 pandemic has had a deep impact on university education, necessitating an abrupt shift from face-to-face learning to distance learning (DL). This has created new challenges, especially for those courses in which practical activities and internships are integral parts of the education program. The aim of this study was to assess the impact of DL on the study progress of a population of pregraduate students of medicine, dentistry, and healthcare professions. The survey was administered through an anonymous questionnaire by sharing a Google Forms link. Demographic data and educational background information were collected to obtain a profile of the participants. Different aspects of DL were investigated, including availability of digital devices, quality of connection, and environmental conditions; other questions focused on the effects of DL on students’ progress and professional maturation. Measures of association were also calculated using the chi-squared test, Cramer V, and Somers D. Among the 372 who participated, the results showed that students had a positive attitude toward online classroom and that DL did not substantially affect their progress. Most of the associations were statistically significant, also highlighting the effect of the degree course on the responses. Some critical issues clearly emerged, however, including the lack of adequate devices and environmental conditions due to economic disparity, poor relationships, suspension of internship programs, and clinical training. The results suggest that DL cannot be considered as a substitute for classroom-based medical education outside an emergency context.

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-&beta, 1), 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-&beta, 1, PDGF-AB, FGF-2, and VEGF levels was detected at T7. At T14, the level of TGF-&beta, 1 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-&beta, 1, 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.

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.

The aim of this study was to review the histologic evidence of reosseointegration and related influencing factors in experimental induced peri-implantitis.An electronic search was performed on Medline for animal studies that included a histometric evaluation of the amount of regenerated bone in contact with an implant surface. Questions raised in the study focused on the role of implant surfaces, bone regeneration and decontamination treatments in achieving reosseointegration. A detailed electronic search was then conducted on MEDLINE (PubMed) up to July 2017.One hundred and one articles were selected as abstract, thirty-seven articles assessed as full-text and sixteen finally included in the study. Reported measurements of reosseointegration varied significantly in the study, from 0 to 3.37 mm. There is histological evidence that reosseointegration can occur after treatment of ligature-induced peri-implantitis. However regenerated bone in contact with bone is generally restricted to the most apical portion of the peri-implant defect.Animal studies of induced peri-implantitis seem to indicate that rough surfaces can enhance reosseointegration as compared to smooth surfaces. With regard to bone regeneration techniques and materials, submerged healing and barrier membranes have shown a positive effect on reosseointegration. No evidence exists, however, about the specific role of different bone substitutes and their ability to improve bone formation. Growth factors have been shown to improve reosseointegration in animal models, though additional study is required to confirm the data. Several decontamination treatments have been shown to promote reosseointegration compared to control; however no specific procedure has proven superior to others in achieving reosseointegration.

Surgical extraction of the third molar can often result in the development of a periodontal pocket distal to the second molar that could delay the healing, and the socket could be colonized by bacteria and lead to secondary abscesses, or it may cause mobility or hypersensitivity. The aim of this case report is to assess the efficacy of a dentin autograft in the prevention of periodontal dehiscences after the surgical extraction of the third molar, obtained by the immediate grinding of the extracted tooth. A healthy 18-year-old male patient underwent surgery of both impacted mandibular molars: right postextractive socket was filled with grinded dentin; then, the left one was filled with fibrin sponge. The patient was followed up for six months, and clinical and radiographic assessment were performed: measurements of plaque index (PI), bleeding on probing (BOP), gingival index (GI), clinical attachment level (CAL), and probing pocket depth (PPD) were done before surgery and repeated at 90 and 180 days after the extractions. Measurements made at six months after the surgery revealed that the grafted site was characterized by a minor depth of the pocket if compared with the nongrafted site, with no clinical/radiographic signs of complications.

This report is devoted to analyze the effect that compulsory vaccination has on the compliance of the population, compared with the results obtained by massive campaigns for optional vaccinations. The implementation of a specific software for the management of individual schedules helps to reach a substantial complete coverage of the individuals for the first ones, while improving but incomplete results regard the vaccines against pertussis and measles-mumps-rubella, optional in Italy. The optimization of data management at the local health unit level improves the quality and the satisfaction of the work performed by the personnel, but has a limited effect on the already nearly complete coverage for the compulsory immunizations. The mounting percentage of children immunized with optional vaccines can be explained both by the massive campaigns of information conducted in recent years and by the better tracking of individual immunization schedules.