The role of oral microbiota in the development of oral mucositis in pediatric oncology patients treated with antineoplastic drugs: a systematic review.

BACKGROUND: In the pediatric oncology population, oral mucositis as a consequence of chemotherapy is a highly prevalent complication which strongly affects both the quality of life and treatment possibilities of the patients. Still, the etiopathological mechanisms carrying to its development are not fully understood, although a possible role of oral dysbiosis has been previously investigated with unclear conclusions. The aim of this systematic review was to assess the available evidence on the role of microbiota in the development of oral mucositis. METHODS: A systematic literature search was performed following PRISMA guidelines. Three electronic databases were searched up until April 2023 and a following manual search included the reference lists of the included studies and reviews. Studies reporting microbiological and clinical data of pediatric patients treated by antineoplastic drugs were included. RESULTS: Thirteen studies met the inclusion criteria, reporting an average mucositis prevalence of 57,6%. Candida albicans infections were frequently observed in studies performing microbiological analysis on oral lesions, in contrast with the low rate detection of the Herpes simplex viruses. Bacterial species such as coagulase-negative Staphylococci and Streptococcus viridans were detected more frequently on lesion sites. Studies reporting a quantitative analysis of the general flora did not show comparable results. Risk of bias assessment among studies was generally considered high or very high. CONCLUSIONS: While the specific role of certain microbiological agents, such as Candida albicans, was frequently reported among studies, data regarding the general dynamics of oral microbiota in the development of oral mucositis are lacking in the current literature. Thus, more studies are needed to provide the knowledge required in order to improve protocols for the prevention and treatment of this threatening complication.

Soybean Oil-Based 3D Printed Mesh Designed for Guided Bone Regeneration (GBR) in Oral Surgery.

This study aims to obtain a cyto-compatible 3D printable bio-resin for the manufacturing of meshes designed from acquired real patients' bone defect to be used in future for guided bone regeneration (GBR), achieving the goal of personalized medicine, decreasing surgical, recovery time, and patient discomfort. To this purpose, a biobased, biocompatible, and photo-curable resin made of acrylated epoxidized soybean oil (AESO) diluted with soybean oil (SO) is developed and 3D printed using a commercial digital light processing (DLP) 3D printer. 3D printed samples show good thermal properties, allowing for thermally-based sterilization process and mechanical properties typical of crosslinked natural oils (i.e., E = 12 MPa, UTS = 1.5 MPa), suitable for the GBR application in the oral surgery. The AESO-SO bio-resin proves to be cytocompatible, allowing for fibroblast cells proliferation (viability at 72 h > 97%), without inducing severe inflammatory response when co-cultured with macrophages, as demonstrated by cytokine antibody arrays, that is anyway resolved in the first 24 h. Moreover, accelerated degradation tests prove that the bio-resin is biodegradable in hydrolytic environments.

Permeability of P. gingivalis or its metabolic products through collagen and dPTFE membranes and their effects on the viability of osteoblast-like cells: an in vitro study.

Membrane exposure is a widely reported and relatively common complication in Guided Bone Regeneration (GBR) procedures. The introduction of micro-porous dPTFE barriers, which are impervious to bacterial cells, could reduce the technique sensitivity to membrane exposure, even if there are no studies investigating the potential passage of bacterial metabolites through the barrier. Aim of this study was the in vitro evaluation of the permeability of three different GBR membranes (dPTFE, native and cross-linked collagen membranes) to Porphyromonas gingivalis; in those cases, where bacterial penetration could not be observed, another purpose was the analysis of the viability and differentiation capability of an osteosarcoma (U2OS) cell line in presence of bacteria eluate obtained through membrane percolation. A system leading to the percolation of P. gingivalis broth culture through the experimental membranes was arranged to assess the permeability to bacteria after 24 and 72 h of incubation. The obtained solution was then added to U2OS cell cultures which underwent, after 10 days of incubation, MTT and red alizarin essays. The dPTFE membrane showed resistance to bacterial penetration, while both types of collagen membranes were crossed by P. gingivalis after 24 h. The bacteria eluate filtered through dPTFE membrane didn't show any toxicity on U2OS cells. Results of this study demonstrate that dPTFE membranes can contrast the penetration of both P. gingivalis and its metabolites toxic for osteoblast-like cells. The toxicity analysis was not possible for the collagen membranes, since permeability to bacterial cells was observed within the first period of incubation.

A comparative scanning electron microscopy study between the effect of an ultrasonic scaler, reciprocating handpiece, and combined approach on the root surface topography in subgingival debridement.

OBJECTIVE: This study aimed to analyze the effectiveness of root-shape inserts mounted on a reciprocating handpiece during the procedure of root surface debridement (RSD) on extracted teeth. Three different approaches were compared: ultrasonic scaling, employment of root-shape inserts mounted on a reciprocating handpiece, and a combination of both. MATERIALS AND METHODS: A total of 51 extracted teeth were divided into three groups. The first group was instrumented with an ultrasonic scaler, the second group with flexible root-shape inserts mounted on a reciprocating handpiece (grain size 40, 15, and 4 µm), whereas the final group underwent a combination of both approaches. The time required for the instrumentation was taken. The specimens were subjected to optical and scanning electron microscopy (SEM), and the photographs were evaluated by three examiners who were blinded to the study. The parameters included were: SEM roughness index (SRI) for the roughness calculation, remaining calculus Index (RCI) to evaluate the residual calculus deposits, and loss of tooth substance index (LTSI) to evaluate the loss of tooth substance caused by instrumentation. RESULT: The results revealed that the time taken for the instrumentation was on average longer when the root-shape inserts were employed alone, meanwhile the combined approach did not show significant difference in comparison with the ultrasonic scaling. The lower average RCI was obtained with a combined approach. The use of root-shape inserts seems to cause a moderate increase in LTSI, especially in a combined approach, whereas it resulted in a better average SRI. CONCLUSION: The employment of root-shape inserts seems to be effective in the RSD for its ability to obtain a smooth and calculus-free instrumented surface, especially when used in combination with an ultrasonic scaler, and their use can so represent a valid approach to be tested in further in vivo studies.

Treatment of intrabony defects using guided tissue regeneration or enamel matrix derivative: a 3-year prospective randomized clinical study.

BACKGROUND: The aim of this randomized, controlled, prospective clinical study was to compare guided tissue regeneration (GTR) to enamel matrix derivative (EMD) for the treatment of intrabony defects in patients with chronic advanced periodontitis. METHODS: Forty (39 evaluable) 3-wall intrabony defects, each with a depth > or = 4 mm measured from the crest of the bony defect, were treated in 40 subjects with advanced chronic periodontitis. Regeneration of angular bone defects was induced using non-resorbable membranes (GTR group; n = 20) or EMD (EMD group; evaluable n = 19). Clinical parameters, including probing depth (PD), clinical attachment level (CAL), gingival recession, radiographic measurement of the defect depth, plaque index, and bleeding on probing, were measured at baseline and at 12 and 36 months following surgery. RESULTS: Twelve months after surgery, sites treated with GTR demonstrated a mean CAL gain of 2.5 +/- 1.2 mm and a mean reduction in PD of 3.5 +/- 1.2 mm compared to baseline. The corresponding outcomes at 36 months were 2.0 +/- 1.1 mm (CAL) and 3.2 +/- 1.1 mm (PD). Sites treated with EMD demonstrated a mean CAL gain of 2.9 +/- 1.4 mm and a mean reduction in PD of 3.5 +/- 1.4 mm at 12 months, with a mean CAL gain of 2.4 +/- 1.2 mm and a mean PD reduction of 3.1 +/- 1.4 mm at 36 months. The differences in PD reduction and CAL gain were statistically significant between the groups and for each time point compared to baseline. Attachment loss was seen in both groups between the 12- and 36-month observations. Measured radiographic bone fill was 57.0% +/- 21% at 12 months and 53.7% +/- 14.3% at 36 months in the GTR group compared to 50.5% +/- 19% at 12 months and 58.8% +/- 14.9% at 36 months in the EMD group. CONCLUSIONS: The treatment of intrabony defects in patients with chronic advanced periodontitis using GTR or EMD led to significantly improved clinical parameters. Tests of statistical significance demonstrated better results with EMD, although the absolute differences between treatment modalities was small. Further studies with a larger number of treated defects are necessary to verify these findings.