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(1) Background: This study aimed to evaluate how laser-activated irrigation (LAI) influences the retention of a fiber post when used before an endodontic filling, as well as after post space preparation. (2) Materials and Methods: Sixty freshly extracted human incisors were selected. The teeth were randomly assigned to three groups-CONVENTIONAL (CONV), PIPS or SWEEPS-and treated endodontically. Each group received irrigation with 1 × 5 mL EDTA (17%) and 3 × 5 mL NaOCl (5.25%). In the first group, the irrigants were not activated, while in the second and third group, LAI was adopted using PIPS and SWEEPS protocols (Lightwalker from Fotona, Ljubliana, Slovenia). After post space preparation, each group received the same irrigation protocol initially established. Sticky posts (everStick Post, GC AUSTRIA GmbH Swiss) were individually adapted to the corresponding post spaces and cemented using dual cure resin cement (Gradia Core, GC Austria GmbH Swiss). All specimens were vertically embedded into self-curing acrylate (Duracryl plus, Spofa Dent, Europe), and each was sectioned into three segments of type A and type B samples for debonding through push-out and pull-out tests. The results were statistically analyzed. (3) Results: The pull-out test showed the superiority of the SWEEPS group, with a mean fracture force of 133.0 ± 50.7 N, followed by the PIPS group, with 102 N, with a lower standard deviation of ± 34.5 N. The CONV group registered the lowest fracture force. Concerning the push-out test, the SWEEPS group showed superior shear stress in comparison to the other two groups (13.45 ± 4.29 MPa); the CONV group was inferior, with shear tension values of 8.31 ± 4.67 MPa. (4) Conclusions: It can be stated that the SWEEPS and PIPS protocols resulted in considerably higher fiber post retention than the conventional method, whereas the SWEEPS protocol was superior to the PIPS protocol.

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Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent and aggressive neoplasms of this anatomical region. Many studies evaluated the neoplastic cells, but few works focused on the tumor microenvironment. In the present study, we investigated the distribution and mast cell density (MCD) in malignant and premalignant lesions of the oral cavity, tongue, pharynx, and larynx. There were analyzed 52 specimens of HNSCC, and 15 biopsies taken from patients with dysplasia. Results were compared with those found in a control group of 10 biopsies of oral mucosa from patients with inflammatory diseases. Slides stained with Hematoxylin-Eosin were used for the histopathological diagnosis and grade, and mast cells (MCs) were identified by immunohistochemistry, using anti-MC tryptase. MCs were counted using a method similar to that proposed for microvessel density. We found a significant increase in the number of MCs from the normal oral mucosa until overt carcinoma. Unlike normal tissues, in HNSCC, many MCs were found between tumor cells. We found no relationship between MCs and blood vessels in the tumor area. A significant statistical correlation was found between dysplastic and malignant tumors, but not between tumors with a different grade. Also, it was not found relationship between MCD and the anatomical location of the tumor. Based on these results, we believe that MCD evaluated by anti-MC tryptase is an independent factor of prognosis and reflects an unfavorable outcome.

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(1) Background: This study aimed to assess the pulpal response of primary teeth by pulse-oximetry (PO) in a canine model, following direct pulp capping (DPC). (2) Methods: Forty-eight primary teeth from eight canine subjects were divided into three treatment groups, based on the DPC material­calcium hydroxide (CH), MTA, BiodentineTM)­and three corresponding control groups. Data from PO pulp testing were correlated with laser Doppler flowmetry (LDF) testing, computer tomographic (CT) densitometry and histological analysis; the experiment lasted 14 days. (3) Results: SpO2 recordings revealed statistically significant differences (p = 0.002, <0.05) between the treatment and control groups, and no significant differences (p = 0.257, >0.05) were observed between treatment groups. LDF recordings showed significant differences (p = 0.002, <0.05) between the treatment and control groups and identified significant differences between materials (p = 0.001, <0.05). CT densitometry indicated vital pulps in all teeth, with pulpal inflammation detected in 6/8 CH-capped teeth and 2/8 MTA-capped teeth. Histologic evaluation confirmed vital pulp in all specimens, with different degrees of inflammation. (4) Conclusions: Within its limitations, the present study confirms the diagnostic value of PO evaluation of pulpal status in primary teeth with histologic means after pulp-capping procedures in a canine model. However, various degrees of pulpal inflammation elicited by different pulp-capping materials seem not to correlate with the obtained PO values.

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BACKGROUND: In orthodontic therapy, the enamel around brackets is very susceptible to bacterial-plaque retention, which represents a risk factor for dental tissues. The aim of this study was to evaluate the effect of methylene blue and a chlorophyllin-phycocyanin mixture, used with and without light activation, in contrast with a 2% chlorhexidine solution, on Streptococcus mutans colonies. METHODS: Twenty caries-free human extracted teeth were randomized into five groups. A Streptococcus mutans suspension was inoculated on teeth in groups B, C, D, and E (A was the positive-control group). Bacterial colonies from groups C, D, and E (B was the negative-control group) were subjected to photosensitizers and 2% chlorhexidine solution. For groups C and D, a combined therapy consisting of photosensitizer and light activation was performed. The Streptococcus mutans colonies were counted, and smears were examined with an optical microscope. Two methods of statistical analysis, unidirectional analysis of variance and the Tukey-Kramer test, were used to evaluate the results. RESULTS: A statistically significant reduction in bacterial colonies was detected after the combined therapy was applied for groups C and D, but the most marked bacterial reduction was observed for group D, where a laser-activated chlorophyll-phycocyanin mixture was used. CONCLUSIONS: Photodynamic therapy in combination with methylene blue or chlorophyllin-phycocyanin mixture sensitizers induces a statistically significant decrease in the number of bacterial colonies.

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Malignant tumors of the oral cavity have a growing incidence, most being squamous cell carcinomas, generally called oral cancers (OCs), clinically detected at various stages of natural evolution. The increased incidence in Romania in recent years and the lack of conclusive data have led to the development of this study. The main purpose of this study was to assess the molecular profile of tumors, the types of blood vessels associated with the tumor, and expression of tumor immunomarkers. Regarding morphological findings, focal epithelial hyperplasia, dysplastic lesions, typical mitoses, perineural invasion, parakeratosis and keratosis beads, intracytoplasmic keratinization were observed. Microvascular density was higher in the tumor area compared to the peritumoral area. Lymphovascular invasion was identified in 13% of cases, which also presented regional lymph node metastases. Podoplanin expression was identified in 79% of cases which were tested positive for the D2-40 immunomarker. All p53-positive cases co-expressed epidermal growth factor receptor (EGFR), half of the EGFR-positive cases co-expressed p53, and co-expression of CD117 and p63 was identified in 80% of EGFR-positive∕cytokeratin 5 (CK5)-positive cases being proposed the basal-like subtype of OCs, defined as EGFR-positive∕CK5-positive, CD117-positive and p63-positive. Results support the need for molecular classification of OCs based on of tumor immunomarker expression and gene analysis.

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The current limits of the endodontic disinfection strategies are not only a result of bacterial biofilm growth mode inside the root canals, they are equally due to the anatomical complexity of the root canal system, of its structure, of the dentin composition and of the factors associated with chemical disinfectants. One of the major problems is the fact that a great part of the endodontic anatomy remains uninstrumented after conventional treatment and even the accessible parts of the root canals are covered in smear layer, which results as a by-product of the instrumentation and acts as a barrier for irrigants, medication and even influencing the quality of the endodontic filling. Therefore, strategies in advanced disinfection in endodontics are developed and tested in order to meet these challenges. The present study aims to assess the possibility of improving the debridement of the root canals by using erbium-doped yttrium-aluminum-garnet (Er:YAG) laser radiation. We used extracted teeth, which were subjected to the conventional treatment protocol and then divided into three study groups: the negative control group and two other groups, which were exposed to laser radiation using two energy levels. Scanning electron microscopy (SEM) revealed the efficiency of the laser aided treatment versus the conventional methods of cleaning and disinfection of root canals.

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