Non-resorbable PTFE membranes are frequently used in dental-guided bone regeneration (GBR). However, there is a lack of detailed comparative studies that define variations among commonly used PTFE membranes in daily dental clinical practice. The aim of this study was to examine differences in physicochemical and mechanical properties of several recent commercial PTFE membranes for dental GBR (Cytoplast^TM TXT-200, permamem^®, NeoGen^®, Surgitime, OsseoGuard^®-TXT, OsseoGuard^®-NTXT). Such differences have been rarely recorded so far, which might be a reason for the varied clinical results. For that reason, we analyzed their surface architecture, chemical composition, tensile strength, Young’s modulus, wettability, roughness, density, thickness and porosity. SEM revealed different microarchitectures among the non-textured membranes; the textured ones had hexagonal indentations and XPS indicated an identical spectral portfolio in all membranes. NeoGen^® was determined to be the strongest and OsseoGuard^®-TXT was the most elastic. Wettability and roughness were highest for Surgitime but lowest for OsseoGuard^®-NTXT. Furthermore, permamem^® was the thinnest and NeoGen^® was identified as the thickest investigated GBR membrane. The defect volumes and defect volume ratio (%) varied significantly, indicating that permamem^® had the least imperfect structure, followed by NeoGen^® and then Cytoplast ^TM TXT-200. These differences may potentially affect the clinical outcomes of dental GBR procedures.

Oral squamous cell carcinoma (OSCC) is a highly aggressive form of oral cancer. Probiotic lactobacilli have demonstrated anticancer effects, whilst their interaction with Streptococcus mutans in this context remains unexplored. The objective of this study was to investigate the antiproliferative effect of Lactobacillus acidophilus on OSCC and to understand the effect of S mutans on OSCCs and whether it affects the antiproliferative potential of L acidophilus when co-exposed to OSCC. The human head and neck squamous cell carcinoma cells of the oral cavity (HNO97 cell line) were exposed to cultures of L acidophilus and S mutans separately and in combination. Further, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to assess the viability of HNO97 cells. Bacterial adhesion to HNO97 cells was examined by confocal microscopy and apoptosis by Nexin staining. To understand the underlying mechanism of apoptosis, expression of the tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) gene and protein were determined by real-time polymerase chain reaction and quantitative enzyme-linked immunosorbent assay, respectively. A significant decrease (53%-56%) in the viability of HNO97 cells on exposure to L acidophilus, S mutans, and the 2 species together demonstrated the antiproliferative activity of L acidophilus and S mutans. Both bacteria showed adhesion to HNO97 cells. The expression of the TRAIL gene increased 5-fold in HNO97 cells on treatment with L acidophilus and S mutans, which further increased to ∼17-fold with both species present. Expression levels of the TRAIL protein were significantly (P < .05) increased in bacteria-treated cell lysates. Further, bacteria-treated HNO97 cells exhibited lower live and intact cell percentages with higher proportions of cells in early and late apoptotic stages. L acidophilus exhibits the antiproliferative activity against OSCC cells possibly partially via a TRAIL-induced mechanism of apoptosis, which is not affected by the presence of S mutans. These findings may encourage further investigation into the possible therapeutic application of probiotic L acidophilus in OSCC.

Guided tissue regeneration (GTR) membranes are used for treating chronic periodontal lesions with the aim of regenerating lost periodontal attachment. Spatially designed functionally graded bioactive membranes with surface core layers have been proposed as the next generation of GTR membranes. Composite formulations of biopolymer and bioceramic have the potential to meet these criteria. Chitosan has emerged as a well-known biopolymer for use in tissue engineering applications due to its properties of degradation, cytotoxicity and antimicrobial nature. Hydroxyapatite is an essential component of the mineral phase of bone. This study developed a GTR membrane with an ideal chitosan to hydroxyapatite ratio with adequate molecular weight. Membranes were fabricated using solvent casting with low and medium molecular weights of chitosan. They were rigorously characterised with scanning electron microscopy, Fourier transform infrared spectroscopy in conjunction with photoacoustic sampling accessory (FTIR-PAS), swelling ratio, degradation profile, mechanical tensile testing and cytotoxicity using human osteosarcoma and mesenchymal progenitor cells. Scanning electron microscopy showed two different features with 70% HA at the bottom surface packed tightly together, with high distinction of CH from HA. FTIR showed distinct chitosan dominance on top and hydroxyapatite on the bottom surface. Membranes with medium molecular weight showed higher swelling and longer degradation profile as compared to low molecular weight. Cytotoxicity results indicated that the low molecular weight membrane with 30% chitosan and 70% hydroxyapatite showed higher viability with time. Results suggest that this highly segregated bilayer membrane shows promising potential to be adapted as a surface layer whilst constructing a functionally graded GTR membrane on its own and for other biomedical applications.

The coronavirus disease 2019 (COVID-19) pandemic has had a significant impact on dental education worldwide. Due to the rapid spread of COVID-19 across Kuwait, it was essential for the Faculty of Dentistry (FoD) at Kuwait University to make appropriate modifications to the functioning of the dental school. The FoD’s goal was not only to ensure a safe environment for its staff, students, and patients but also to sustain the students’ academic progression. The FoD adopted several measures including the establishment of a COVID-19 response team, adoption of a blended-learning model, and phase-wise re-opening of the dental center. This paper discusses on the strategies that the FoD adopted, in response to the challenges posed by the pandemic.

Peri-implant keratinized mucosa (PI-KM) may support implant survival. Acellular collagen matrices (aCMs) have been widely used to facilitate soft tissue regeneration. The aim of this study was to investigate clinical outcomes obtained with the use of an aCM (mucoderm^®) to enhance PI-KM. In this retrospective non-randomized case series, 27 restored implants in 14 patients (eight males and six females, mean age = 56 years) with a PI-KM width ≤ 1 mm were followed for 6 months. It was demonstrated that aCM grafts augmented PI-KM effectively (mean increase of 5.4 mm; >533%) without a significant change in bleeding on probing (BOP) from baseline. The mean aCM shrinkage was 3.9 mm (42%). Gender, area, arch, and BOP did not influence PI-KM augmentation or aCM shrinkage significantly. The present results demonstrated that the examined aCM was effective and predictable for attaining a band of keratinized tissue, while avoiding graft donor site harversting.

Objectives: Guided bone regeneration (GBR) is a core procedure used to regenerate bone defects. The aim of the study was to investigate the adherence of Candida albicans on six commercially available polytetrafluoroethylene (PTFE) membranes used in GBR procedures and the subsequent clinical consequences.Materials and Methods: Six commercially available PTFE membranes were tested. Two of the membranes had a textured surface and the other four a plane, nontextured one. C. albicans (ATCC 24433) was cultured for 24 h, and its cell surface hydrophobicity was assessed using a modified method. C. albicans adhesion to membrane discs was studied by scanning electron microscopy (SEM) and real‐time polymerase chain reaction (PCR).Results: C. albicans was found to be hydrophobic (77.25%). SEM analysis showed that C. albicans adherence to all membranes examined was characterized by patchy, scattered, and small clustered patterns except for one nontextured membrane with a most rough surface in which a thick biofilm was observed. Real‐time PCR quantification revealed significantly greater adhesion of C. albicans cells to PTFE membranes than the control membrane (p ≤ .001) with the membranes having a textured surface exhibiting the highest count of 2680 × 10⁴ cells/ml compared to the count of 707 × 10⁴ cells/mL on those with a nontextured one (p ≤ .001). One membrane with nontextured surface, but with most rough surface was found to exhibit the highest count of 3010 × 10⁴ cells/ml (p ≤ .05).Conclusion: The results of this study indicate that C. albicans adhesion on membranes' surfaces depends on the degree of surface roughness and/or on the presence of a texture. Textured PTFE membranes and/or membranes high roughness showed significantly more adhered C. albicans cells. These findings can impact the surgeon's choice of GBR membrane and postoperative maintenance.