Classically, periodontal defects have been differentiated based on bone resorption patterns into "supraosseous" ("suprabony") and "infraosseous" ("infrabony") (Goldman & Cohen, 1958). These authors defined suprabony defects as those where the base of the pocket is located coronal to the alveolar crest. On the other hand, infrabony defects are those with apical location of the base of the

Background Mutations of the tumour-suppressor gene TP53 are the most frequent somatic genomic alterations in head and neck squamous cell carcinoma (HNSCC). However, it is not yet clear whether specific TP53 mutations bear distinct clinical and pathophysiological significance in different HNSCC subgroups. Methods A systematic bioinformatics appraisal of TP53 mutations was performed on 415 HNSCC cases available on The Cancer Genome Atlas (TCGA). The following features were analysed and correlated with known clinicopathological variables: mutational profile of TP53, location (within secondary structure and predicted domains of p53 protein) and well-known hotspot mutations. Interactome–genome–transcriptome network analysis highlighted different gene networks. An algorithm was generated to develop a new prognostic classification system based on patients’ overall survival. Results TP53 mutations in HNSCCs exhibited distinct differences in different anatomical sites. The mutational profile of TP53 was an independent prognostic factor in HNSCC. High risk of death mutations, identified by our novel classification algorithm, was an independent prognostic factor in TCGA HNSCC database. Finally, network analysis suggested that distinct p53 molecular pathways exist in a site- and mutation-specific manner. Conclusions The mutational profile of TP53 may serve as an independent prognostic factor in HNSCC patients, and is associated with distinctive site-specific biological networks.

Objectives:Oral cancer represents one of the most common malignancies in humans. Its prognosis is still poor, despite the most recent improvements in therapies.An increasing attention is placed on the role of programmed death ligand 1 (PD-L1) in the tumour immunity and its potential function as a marker for tumour prognosis.Whether PD-L1 expression is a prognostic factor for the poor outcomes in oral squamous cell carcinoma is still controversial. This study aimed to investigate, through a meta-analysis, a potential correlation between PD-L1 expression and the prognostic outcomes in patients with oral squamous cell carcinoma. Materials and methods:The studies were identified by searching PubMed, SCOPUS, Web of Science and were assessed by two of the authors. After the selection process, 11 articles met eligibility criteria and were included in the meta-analysis. Quality assessment of studies was performed according to the REMARK guidelines, and the risk of biases across studies was investigated through Q and I 2 tests. Meta-analysis was performed to investigate the association between the PD-L1 expression either overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), gender and lymph node metastasis. Results: A total of 1060 patients were analysed in the 11 studies included in the meta-analysis. Pooled analysis revealed that the expression of PD-L1 did not correlate with poor OS (HR, 0.60; 95% CI: [0.33, 1.10]; P = 0.10), DFS (HR, 0.62; 95% CI: [0.21, 1.88]; P = 0.40), DSS (HR, 2.05; 95% CI: [0.53, 7.86]; P = 0.29 and lymph node metastasis (HR, 1.15; 95% CI: [0.74, 1.81]; P = 0.53). Furthermore, results of the meta-analysis showed that high expression of PD-L1 is two times more frequent in female patients (OR, 0.5; 95% CI: [0.36, 0.69]; P < 0.0001) compared to males. For all the three outcomes analysed, a high rate of heterogeneity was detected (I 2 > 50%).

The primary objective of endodontic therapy is to create a biologically acceptable environment within the root canal system that allows for the healing and maintenance of the health of the peri-radicular tissue. Bacteria are one of the main causes of pulp problems, and they have different methods of penetrating and invading the endodontic space such as through carious lesions, traumatic pulp exposures, and fractures. The types of bacteria found range from facultative anaerobes to aerobes, up to the most resistant species able to survive in nutrient-free environments; the bacterial species Enterococcus faecalis belongs to this last group. Enterococcus faecalis is considered one of the main causes of recurring apical periodontal lesions following endodontic treatment, with persistent lesions occurring even after re-treatment. The review presented in this paper was performed in accordance with the PRISMA protocol and covers articles from the related scientific literature that were sourced from PubMed, Scopus, and Google Scholar using the following terms as keywords: “endodontic treatment”, “endodontic bacteria”, “microbial endodontic”, and “endodontic failure”. Only the articles considered most relevant for the purposes of this paper were read in full and taken into consideration for the following review. The results show that Enterococcus faecalis, Actinomycetes, and Propionibacterium propionicum are the species most frequently involved in persistent radicular and extra-radicular infections.

Endodontic treatment consists of different working procedures, such as the isolation of the operating field, pulp chamber access, and cleaning and shaping phases with at last the need of a three-dimensional filling of the canals. Each step requires a series of single-use or sterilizable instruments. We have performed a systematic review of different sterilization and disinfection procedures aiming at drawing up a disinfection and sterilization procedure to be used on endodontic instruments. A search on PubMed and Scopus was carried out using the following keywords: “endodontic sterilization,” “endodontic autoclave,” “decontamination dental bur,” “sterilization dental burs,” and “gutta-percha points sterilization.” Eligible articles were included in the qualitative and quantitative analysis. Results of the meta-analysis showed that the most effective method in sterilization is autoclaving. The qualitative analysis showed that the use of single-use or first-use instruments requires presterilization or sterilization procedures, and for reusable tools, attention must be paid to the removal of debris deposited on the blades, not easy to remove manually.