DentalCare Logo

The Oral Microbiome: A New View of Plaque Biofilm

Course Number: 676


Antimicrobial agents incorporated into oral care products such as toothpastes and mouthrinses, complement mechanical plaque control devices. Continuing research explores new antimicrobial agents that target only the pathogenic microbes without destroying the beneficial species. With the focus being on maintaining symbiosis rather than killing all microbes, these products must be at concentrations that inhibit the growth of pathobionts without elimination of beneficial species.

Recent studies of the effects of chlorhexidine on the oral microbiome, have resulted in evidence of reductions in numerous beneficial species. Along with these reductions in commensal species, this alteration in oral homeostasis resulted in significant reductions in salivary PH, reductions in the buffering capacity of saliva, and increases in salivary lactate. These alterations have all been associated with tooth decay and periodontal disease. Another detrimental effect of chlorhexidine found in these studies was decreased concentrations of oral nitrite, which plays a significant role in stabilizing blood pressure.14 Further studies however are required to explore the actual extent of the impact chlorhexidine has on altering blood pressure. Use of antimicrobial mouthrinses such as chlorhexidine digluconate, along with others having high enough concentrations of alcohol to kill oral microbes, should be reconsidered.