主题：国际最新研究成果，茶树油在口腔护理用品的疗效确切

The essential oil of Melaleuca alternifolia has a similar antimicrobial activity to that of chlorhexidine, although their mechanisms of action differ. A main component of the oil, 1,8-cineole, has additional anti-inflammatory properties. It was thought that tea tree oil may have therapeutic potential in the treatment of chronic gingivitis and periodontitis as both conditions have bacterial and inflammatory components. An Australian duo performed a double-blind, longitudinal non-crossover trial using 49 subjects with moderate to severe gingivitis, divided into three groups. The test group applied a gel containing 2.5% tea tree oil with a tooth brush, the positive control group used a 0.2% chlorhexidine gel and the negative control a placebo gel. The study lasted eight weeks and the Gingival Index (GI), Papillary Bleeding Index (PBI) and the Plaque Surface Score (PSS) were measured at 0, four and eight weeks. The subjects were instructed to use the gel as a dentifrice, making sure it was in contact with the gingival tissues adjacent to the teeth for a minimum of 2 min twice daily. For 30 min post application no eating, drinking or rinsing was allowed and no other proprietary toothpastes, mouthwashes or other cleaning aids were permitted during the duration of the study. The results were separated into anterior/posterior teeth and buccal/lingual tooth surfaces. The tea tree oil group demonstrated significant reduction in PBI and GI scores, but did not reduce plaque scores, which tended to increase during the latter weeks of the study period. Generally, the chlorhexidine group showed more improvements in PSS than the other groups and had the greatest reduction in plaque scores. There were no adverse reactions to any of the gels. The potent antibacterial activity of tea tree oil in vitro did not translate to a similar result in vivo, as decreased gingival inflammation occurred without a concomitant decrease in plaque scores. The beneficial effects of M. alternifolia essential oil were thus ascribed to its anti-inflammatory properties and it was postulated that it may be a useful addition to the current range of periodontal treatment options.