Key Words: Chlorhexidine Gluconate, Dental Plaque, Adjunct Therapy, Oropharyngeal Infections.

For decades now, Chlorhexidine (CHX) has been considered a 'gold standard' as an efficient antibacterial and therapeutic oral rinse.[1] The use of this is however not global as a pre-procedural therapeutic rinse. The most preferred form of CHX is 0.2%v/w chlorhexidine gluconate solution, commonly used as an antiseptic mouth rinse and recommended by the majority of dental professionals worldwide. CHX is primarily used in the treatment of gingivitis, inhibition of dental plaque, as an adjunct to supportive periodontal care, antiseptic oral rinse following dental extractions and surgeries, prevention of alveolar osteitis, treatment of halitosis, and prevention of oral candidiasis.[2-6] Few have even advocated the use of CHX for the disinfection of root canals in endodontics.[7] While others have strongly recommended its use in irradiated patients and those undergoing chemotherapy for the treatment of head and neck carcinomas.[8]

CHX 0.2% is the leading antiseptic for controlling gingivitis, and plaque inhibition.[9] Although it is a potent antiseptic when used and is known to considerably bring down the microbial count; it is however, more frequently employed routinely as a postoperative preventive adjunct measure rather than a routine preoperative procedure.[10] Its use, after speculation, is invariably limited to the field of dentistry.
This study was targeted to check the efficacy of 0.2% CHX on the culturable microorganisms in the oral and oropharyngeal region, and was aimed at justifying its use as a standard protocol prior to any procedures being carried out in the said regions and to further recommend it as an adjunct therapy in treatment of all oropharyngeal infections by all specialties of medicine, not just in dentistry.

A group of 20 non-smoking volunteers were picked with no age and sex predilection. The group consisted of 10 men and 10 women with the mean age of the group being 31.2 years. The volunteers were thoroughly examined and found to be free from any active oropharyngeal and dental infections. Thorough complete oral hygiene procedures were carried out on each of the subjects prior to the study to ensure complete plaque elimination. Three sets of swabs were collected from each volunteer.

The first set was collected immediately after the prophylactic procedure was completed and labelled A. The subjects were then instructed not to perform any oral hygiene procedures for 24 hours (the subjects were to refrain from procedures such as brushing, flossing, rinsing etc.). A second set was then collected after 24 hours and labelled sample B. After the collection of B, the subjects were then made to rinse with 10 ml. of undiluted 0.2% chlorhexidine gluconate solution thoroughly for 60 seconds (as recommended by manufacturer's instructions). The third set of swabs were then collected from the subjects and labelled C.

The swabs were collected from predetermined sites in the oral cavity - upper and lower molar regions, dorsum of the tongue and the tonsilar region from each of the subjects.

The swabs were then cultured for bacterial colonies under standard incubatory conditions on blood and chocolate agar, which are the most common culture media used for the culture of oropharyngeal bacteria.[11] Standardised streaking techniques were followed using a sterile loop of known volume (1/500ml).

Estimation Of bacterial numbers:[12] The colonies were then counted after 48 hours. The total numbers of bacterial colonies were counted and multiplied using a factor based on the volume of the streaking loop. This procedure was standardized using quality control measures and followed on all the culture plates.[13] The scoring pattern used in this study is as follows:
Score 0 - No growth.
Score I - <103 colony forming units (CFU)
Score II - 103-104 CFU
Score III - 104-105 CFU
Score IV - >105 CFU
Experimental data reveals that a colony count less than 10-6 is required to meet the pharmacological definition of 'sterile.'[14]

The results obtained were then scored and tabulated in Table-1. The mean scores were then calculated for A, B & C and a Kruskal-Wallis test was used for the statistical analysis of the results.

The results of this study indicate that the mean scores for group A (mean=1.5500) was considerably lower than B (mean=3.7500) & C (mean=2.6000). The mean values for group C further showed a reduction in the colony numbers than B.

On statistical analysis a significant difference was found between groups C & B (p value = 0.0004).

The oral cavity is a reservoir for commensal and pathogenic micro-organisms. A complete state of asepsis is hardly prevalent in the oral cavity. This however does not imply that there is an active infection at all times, but certainly depicts the constant presence of micro-organisms which may result in their frequent transmission to the different communicating regions of the oral cavity such as the oropharnyx, lungs, nasal cavity, eustachian canal, sinuses etc. This may not pose a significant threat in a state of normalcy, but, in the presence of an existing infection the normal oral micro flora itself may potentially super add to an existing infection. Conversely, an existing focal sepsis in the oral cavity may act as a continual supply of pathogens and pus resulting in a chronic insidious recurrent oropharyngeal infection of some sort, which is usually not responsive to antibiotic therapy. Such cases usually resolve with the elimination of the source of infection but also can be significantly controlled to a great extent at the onset itself with a direct local reduction in the pathogenic numbers through the use of local antiseptics such as chlorhexidine.[15]

The primary application of CHX is predominantly restricted to the field of dentistry, that too, as a post procedural therapeutic rinse.9 The focus must however shift, as the study clearly evidences its potential antiseptic actions. It will indeed be certainly beneficial if the prescription of CHX mouth-rinse is added as an adjunct to conventional therapy. [16]

The outcome of this simple clinical trial clearly illustrates the substantial reduction in the bacterial numbers of the cultures obtained from samples with and without of the use of CHX mouth rinse. It only progresses to highlight further the compelling need to maintain oral asepsis. Therefore, from the obtained results the authors conclude - that a significant decrease in the bacterial count is present with the use of CHX. Therefore the clinical relevance of the study can substantiate the following measures -
That it is imperative to use CHX mouth rinse as a recommended 'pre-procedural' standard protocol for all dental related procedures and prior to any procedures performed in the oral and oropharyngeal region.

And further propose that it may be routinely prescribed by other practitioners in various other specialties of medicine routinely as a mouth rinse to augment their conventional therapeutic methods for treating oropharyngeal and other related infections, so as to definitely ensure an infection free and possibly a sterile oral and oropharyngeal environment.