Microbiological effects of mouthrinses containing antimicrobials

A number of mouthrinse formulations containing antimicrobials have been evaluated to determine their effectiveness as antiplaque and/or antigingivitis agents. These have included the bis-biguanides, phenols, quaternary ammonium compounds, oxygenating compounds, plant extracts, fluorides, antibiotics and antimicrobial combinations. These mouthrinses have often been tested as adjuncts to normal oral hygiene procedures as well as in the experimental gingivitis model. 2 agents in particularly, chlorhexidine gluconate and listerine, have been shown to both inhibit or reduce plaque accumulation and the severity of gingivitis. Chlorhexidine has been reported to reduce the accumulation of plaque by approximately 60% and the severity of gingivitis by 50-80% as determined by improvements in clinical indices. A 0.12% chlorhexidine gluconate rinse resulted in significant reductions after both 3 and 6 months use in the numbers of total anaerobes, total aerobes, streptococci, and actinomyces recovered from supragingival plaque. Listerine has been reported to retard the development of plaque by 45 to 56% and to reduce existing plaque by 39 to 48%. Gingivitis scores were reduced as much as 59%. Microbial studies have shown that the effect of listerine is exerted against the total microbial mass and results in an overall decrease in both the biomass and the activity. Long-term use of neither mouthrinse, chlorhexidine or listerine, resulted in the emergence of opportunistic or oral pathogens. Preliminary data obtained following the use of a novel mouthrinse consisting of a combination of povidone-iodine and hydrogen peroxide appears promising. This combination was more effective than was more effective than either single component alone in reducing gingivitis scores.(ABSTRACT TRUNCATED AT 250 WORDS)