A systematic review was performed to evaluate the biological effects of Cannabidiol (CBD), one of the major components of Cannabis Sativa, on normal human healthy cell populations in terms of cell viability, proliferation, migration, apoptosis and inflammation. Inclusion criteria were: studies on cell lines and primary cell culture from healthy donors, CBD exposure as variable, no CBD exposure as control and published in English language. Quality assessment was based on ToxR tool, with a score of reliability ranging from 15 to 18.Following the PRISMA statement, three independent reviewers performed both a manual and an electronic search using MEDLINE via PubMed, Scopus, Web of Science and Cochrane. From a total of 9437eligible articles, 29 studies have been selected. The average quality assessment score was 16.48.Theresults showed heterogeneous CBD concentration exposure (0.01-50 μM or 0.1 nmol/mL-15 mg/mL). The definition of a threshold limit would allow the identification of specific effects on expected outcomes. From the data obtained CBD resulted to inhibit cell viability in a dose-dependent manner above 2 μM, while in oral cell populations the inhibitory concentration is higher than 10 μM. Moreover, it was observed a significantly inhibition of cell migration and proliferation. On the contrary, it was highlighted a stimulation of apoptosis only at high doses (from 10 μM).Finally, CBD produced an anti-inflammatory effect, with a reduction of the pro-inflammatory cytokine gene expression and secretion. CBD down-regulated ROS production, although at high concentrations (16 μM) increased ROS-related genes expression. The diffusion of CBD for therapeutic and recreational uses require a precise definition of its potential biological effects. A thorough knowledge of these aspects would allow a safe use of this substance without any possible side effects.

The aim of this study is to investigate the Erbium:Yttrio-Aluminum-Granate (Er:YAG) laser photothermal and mechanical effects on cariogenic species concentration and on the microbial load composition of therapeutic cavities, in order to evaluate the possible micro-organisms reduction and make a comparison with manual and rotating conventional therapy (CT). A clinical trial was designed, including adults with active deep carious lesions on permanent teeth who were divided into two groups, i.e., control group and intervention group treated with CT and Er:YAG therapy, respectively. Before and after any conservative treatment, two oral samples were collected using a small sterile microbrush scrubbed within the base of the dentinal cavity tissue. The percentage of reduction and the colony-forming units (CFUs) count after Er:YAG and conventional treatments were compared for total microorganisms, including Candida spp., Streptococcus spp., and Lactobacillus spp. The microbial reduction varied from 90.2% to 100% and was significantly observed for total microorganisms and Streptococcus spp. (p < 0.05). The Er:YAG laser shows the potential for clinical applications, especially with paediatric and complicated patients, thanks to its minimally invasive properties and its effect on the reduction of microbial load.

Human gingival fibroblasts were cultured in vitro using as substrates an extracellular matrix (matrix) and polytetrafluoride (PTFE) membranes, which are used in guided tissue regeneration. To test the degree of biocompatibility of these membranes, the cellular proliferation and the accumulation of extracellular matrix (ECM) macromolecules were considered as parameters. The fibroblasts were cultured in vitro for 24 and 48 hours without serum on plastic, matrix, and PTFE membranes in the presence of ³H‐thyrnidine, ³H‐glucosamine, and ³H‐proline to study the neo‐synthesis of DNA, glycosaminoglycans (GAG), and collagen proteins, respectively. Studies on cell proliferation showed that fibroblasts grown on matrix membrane significantly increased ³H‐thymidine incorporation, while fibroblasts grown on PTFE membrane decreased ³H‐thymidine incorporation, compared to plastic used as a control. Moreover, the PTFE membrane induced a marked decrease of collagen and GAG accumulation both in the cellular and extracellular pool, while the matrix membrane provoked a decrease of the two macromolecules in the cellular pool and an increase in the extracellular one, compared to the control. The data we obtained demonstrate that matrix membranes are the most suitable to stimulate both cellular proliferation and ECM macromolecule accumulation. J Periodontol 1997;68:857–863.

Background: Barrier membranes are used to prevent downgrowth of the oral mucosa along the root surface and to allow alveolar bone regeneration in guided tissue regeneration. Several studies have demonstrated bone regenerates in the presence of bioabsorbable and non‐resorbable membranes, but no studies have compared multiple bioabsorbable barriers to one another and to non‐resorbable barriers. This study evaluated the in vitro influence of bioabsorbable and non‐resorbable membranes on specific parameters of human osteoblast activity.Methods: Human osteoblasts were cultured on bioabsorbable membranes made of collagen, hyaluronic acid, and poly DL‐lactide, and the most common non‐resorbable membrane which is made of expanded polytetrafluoroethylene (ePTFE). The osteoblasts were cultured in vitro for 24 hours on barrier membranes in the presence of ³H‐thymidine and ³H‐proline to study cell proliferation and collagen synthesis. Transforming growth factor‐β₁ (TGF‐β₁) secretion was evaluated in conditioned media using an ELISA kit.Results: The results showed that collagen and poly DL‐lactide stimulated DNA synthesis more than ePTFE and hyaluronic acid. All bioabsorbable membranes significantly increased collagen synthesis and alkaline phosphatase activity. Collagen and hyaluronic acid increased secretion of TGF‐β₁, a growth factor involved in bone remodeling.Conclusions: These data suggest bioabsorbable membranes, particularly collagen and hyaluronic acid, may promote bone regeneration through their activity on osteoblasts. J Periodontol 2001;72:753‐759.