Gingival overgrowth is a known side effect of drugs such as phenytoin, cyclosporin A, and amlodipine (AML). Several recent reports have shown that gingival overgrowth induced by AML is caused by gingival inflammation as well as by a decrease in apoptosis and an increase in proliferation, which is mediated by the cell cycle, in gingival fibroblasts (GFs). It has also been reported that both phenytoin- and cyclosporin A-induced gingival overgrowth are caused by tumour necrosis factor (TNF)-α, which is an inflammatory cytokine and a cellular apoptosis inducer. However, few reports have investigated the relationship between AML-induced gingival overgrowth and TNF-α. Therefore, in this study, we evaluated the effect of AML on the cell cycle, apoptotic ability, viability, and total cell number of human GFs (hGFs) in the presence of TNF-α. Cultured quiescent hGFs were stimulated by TNF-α (100 ng/mL) ±AML (1 or 10 μM) or AML alone (1 or 10 μM) and then assessed for their cell cycle phase distribution as well as for the number of apoptotic, viable, and total cells. The results showed that AML treatment significantly suppressed TNF-α-induced apoptosis in hGFs and significantly increased the viability and total number of hGFs in the presence of TNF-α. Thus, these results may be related to the cause of AML-induced gingival overgrowth.

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Infiltration anesthesia is often employed in dental treatments and causes intense pain. Superficial anesthesia is used as pretreatment; however, its retention in the oral mucosa is poor and its anesthetic effect is unsatisfactory. A method was devised to relatively easily improve retainability of superficial anesthetic in the oral mucosa by placing a columnar piece of cotton near where superficial anesthetic is applied and pulling the lower lip anteriorly. This method was compared with a conventional method, i.e., closing the lips after application of superficial anesthetic. Using multiple superficial anesthetics, the appearance of the superficial anesthetic effect outside the application area and analgesic effect during infiltration anesthesia was evaluated in 10 healthy subjects. Alveolar mucosa of the lower incisor region was selected as the test site. The action time was set at 1 minute and pain was evaluated on insertion of the injection needle and infusion of the drug solution using a visual analogue scale. The analgesic effect during infusion of the drug solution was greater using the improved method than the conventional method. The effects of superficial anesthetics were noted outside the application area within 1 minute after drug application with the conventional method, but not with the improved method. These results suggest that the adverse effects of superficial anesthetics may be mitigated by improving retainability in the oral mucosa and that the improved method is effective for improving retainability of drugs in the oral mucosa.

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Promotion of appropriate use of antimicrobial agents is one of the most important problems in nosocomial infection control. The infection control team (ICT) at Showa University Dental Hospital started to use a notification policy for antimicrobial agents (fourth-generation cephalosporins, carbapenems and antimethcillin-resistant Staphylococcus aureus (MRSA) agnents from 2010. In this study, consumption of the antimicrobial agents and the trends of antimicrobial resistance were verified before and after the introduction of the notification policy, and the system was evaluated. Antimicrobial usage density (AUD) of ABPC and CEZ in 2011 was increased remarkable compared with that of in 2009. Total AUD of antimicrobial agents was almost same from 2009 to 2011. Total expenditure of antimicrobial agents had been decreased each year. MRSA, multidrug-resistant Pseudomonas aeruginosa and extended-spectrum beta-lactamase producing enterobacteria were not detected. Therefore, positive intervention by ICT is important for promotion of appropriate use of antimicrobial agents, prevent to increase in drug resistant bacteria and contribute for economic impact on the hospital.

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