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In the original publication [...].
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Cannabis sativa plants have a wide diversity in their metabolite composition among their different chemovars, facilitating diverse anti-tumoral effects on cancer cells. This research examined the anti-tumoral effects of 24 cannabis extracts representative of three primary types of chemovars on head and neck squamous cell carcinoma (HNSCC). The chemical composition of the extracts was determined using High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS). The most potent anti-tumoral extracts were type III decarboxylated extracts, with high levels of Cannabidiol (CBD). We identified extract 296 (CAN296) as the most potent in inducing HNSCC cell death via proapoptotic and anti-proliferative effects. Using chemical fractionation of CAN296, we identified the CBD fraction as the primary inducer of the anti-tumoral activity. We succeeded in defining the combination of CBD with cannabichromene (CBC) or tetrahydrocannabinol (THC) present in minute concentrations in the extract, yielding a synergic impact that mimics the extract's full effect. The cytotoxic effect could be maximized by combining CBD with either CBC or THC in a ratio of 2:1. This research suggests using decarboxylated CBD-type extracts enriched with CBC for future preclinical trials aimed at HNSCC treatment.
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PURPOSE: To study the relation between irretrievable abutment healing caps (AHCs), temperature, and the torque required to remove the AHCs from implants. MATERIALS AND METHODS: Twenty implants, 13 mm long and 4.2 mm in diameter, were inserted into four acrylic boxes and covered with acrylic resin. An AHC was screwed into each implant, using a 30 N/cm torque. The acrylic blocks were placed in a 37°C water bath, and subsequently, a block was removed from the bath, the AHCs were cooled, and the torque needed to release each AHC from the implant was measured using a torque wrench. The cooling methods applied were contact with an ice cube for 10 or 25 seconds or spraying of endodontic refrigerant spray for 3 seconds. The control abutments were similarly tested, but without prior cooling. RESULTS: The application of ice cubes for 10 seconds reduced the mean releasing torque from 29.60 ± 1.22 N/cm to 28.55 ± 1.96 N/cm (P = .01). Cooling the AHCs with ice cubes for 25 seconds reduced the mean required releasing torque from 29.6 N/cm to 27.85 ± 1.22 N/cm (P < .001). Cooling the same abutments using endodontic refrigerant spray for 3 seconds reduced the mean releasing torque to 27.74 ± 2.13 N/cm (P < .001). CONCLUSION: Within the limitations of this study, it is possible to conclude that cooling the AHC reduces the torque required for its release from the implant. This finding may also be relevant to the removal of prosthetic abutments with irretrievable screws.
