Key Words: Listerin and Oral Bacteria Flora

ABSTRACT

The objective of this pilot study was to determine the effects of Listerine mouth rinse in decreasing the salivary flora. This study was done on nine patients with active fixed orthodontic treatment (First upper and lower molar bands and brackets in the remaining teeth). The sample selection was made under the PTNS (Patient Treatment Need System) developed by Dr. Johanseen et. Al., as the standard oral hygiene indicator. To determine the efficacy of Listerine°* mouth rinse, two saliva samples were taken: First, before the mouth rinse with Listerine and second, after the mouth rinse. With the saliva sample dilutions were done (1/100.000)and then cultured for gram positive and gram negative germs, doing the total recount of bacteria developed before and after the mouth rinse. The difference obtained demonstrates a statistical significance of bacteria reduction before and after the mouth rinse (P 0.05).

* Dentist, Specialist in Orthodontics, former asst. Teacher ** Dentist, Assistant teacher at Univ. Autonoma de Manizales *** Bacteriologist, Mgs in research and education U. Autonóma de Manizales.

°* Warner Lambert de Colombia,Cll 62 # 1N-80,Cali

INTRODUCTION

There is a consensus around the world about the high risk of infection to health personnel by a variety of agents capable of producing illness. This risk is associated with the estomathognathic system, and in particular the mouth, which are closely related to the upper respiratory system. This system is the host of a high number of microorganisms; some from the normal flora as well as some associated to pathology, whose main medium for propagation are the nasopharyngeal and bucopharyngeal secretions. Most of the oral bacteria flora are part of the agents from the dental cavities, periodontal disease and endodontic infections.

In dental practice, besides the risk of being in contact with nasopharingeal and oropharingeal secretions, particularly the pathogenic agents from the upper respiratory system, there is an additional risk represented by the contact with blood. Blood is an important vehicle to pathogenic agents, especially of viral type such as : AIDS virus, hepatitis B, C, and Delta.

In this particular ecological environment there is also the risk of cross contamination among patients, assistant personnel and patients due to bacterial or viral agent dissemination through contaminated instruments.

Nevertheless, in some dental practices like orthodontics, there is an assumption that the contamination risk is low due to scarce probability of blood contact during the routine practice with orthodontic patients. Additionally, it is difficult to apply rigorous infection control system to the pliers and instruments between patients. Some authors and government institutions have suggested a technique to minimize the contamination risk; the use of bactericidal mouth rinse before any dental procedure. The OSHA (Occupational Safety and Health Administration) and the AHA (American Heart Association) recommend this procedure as third in priority at the "Minimum control infection program for a Dental Office"¹.

This possibility of reducing the risk of microorganism contamination by mouth rinse (a low priced, easy and fast procedure) guide this pilot study to determine experimentally the efficacy of Listerine mouth rinse application in the reduction of oral bacteria flora in saliva.

MATERIALS AND METHODS

Nine patients who attend routine orthodontic treatment appointments were selected. These patients had fixed orthodontic appliances on the upper and lower dental arch with cemented bands on the four first permanent molars and bonded brackets on the remaining teeth.

To control the oral hygiene variable the PTNS index (Patient Treatment Needs System)was used as a patient selection method. The PTNS was developed by Dr. Johansen et al. in 1973.

The procedure for each patient was as follow:

1. Before seating the patient for the orthodontic procedure, a non-stimulated saliva sample was taken(10 ml).
2. The patient was asked to do the mouth rinse with 20 ml of Listerine for 30 seconds.
3. After 30 seconds of treatment (mouth rinse) the patient eliminated the Listerine from the mouth and after 30 seconds of the Listerine elimination a non-stimulated saliva sample was taken(10 ml).
4. From each sample obtained on each patient, a dissolution of 1/100.000 was done. An aliquot of 10 ul of each saliva dissolution was prepared at the same time in both, agar-blood and tripticase soya-agar for gram-positive and gram-negative aerobic bacteria.
5. Parallel, there was a control sample using distilled water as the mouth rinse, which also was cultured at the same time in both, agar-blood and tripticase agar-soya for gram-positive and gram-negative aerobic bacteria.

Each of the inoculate samples was incubated at 37°C degrees for 24 hours. After this period of incubation the number of colonies was counted. In accordance with the number of colonies found in each culture, the total aerobic bacteria population in each sample was calculated, that is to say, the number of existing microorganism by saliva ml before and after the Listerine mouth rinse.

To tabulate the data, a matrix allocating the number of colonies obtained on each sample before and after treatment was used.

After that, the difference between the number of microorganism obtained in the experimental group was calculated like this:

- Before the mouth rinse. - 30 seconds after the mouth rinse.

Using these before and after mouth rinse obtained values, the microorganism population reduction was estimated and expressed in percentage terms. With the difference obtained, the statistics "T" of Student were applied to matching samples to determine if the observed differences were statistically significant.

RESULTS

First of all, we see the average values obtained before the mouth rinse in the 20 ml saliva sample in patients who are in active orthodontic appliances with brackets, wires and bands in the first four permanent molars; and second, we see the average values obtained in the same patients after the mouth rinse with Listerine for 30 seconds. These observations show that the reduction of bacteria colonies number after the mouth rinse is 85% (table 1).

The "T" value found was Tc 3.69 p < 0.05 which confirms the statistically significant difference between the number of bacteria before the mouth rinse compared with the number of bacteria after the mouth rinse.

In the control sample done before and after the mouth rinse with distillated water, a microbial population reduction of 10% was observed.

DISCUSSION

There are a large number of microbial species gram-positive and gram-negative, aerobic, anaerobic and facultative that are part of the normal oral flora, which include about 400 different species², and there are also those that can spark oral tissue infection on dental, periodontal and other structures.

Nevertheless, there are host and environment factors which alter the normal oral bacterial flora development and favor somewhat the establishment and colonization of microorganisms in the mouth. This is the case of orthodontic appliances in patients subject to fixed orthodontic treatment.

On these patients it has been demonstrated that the use of fixed orthodontic appliances, independent from oral hygiene, increase the gram-negative aerobic bacterial population, lactobacillus and Spirochete in saliva³.

Another microorganism group that can be found in the mouth as pathogenic are the soft tissue and the upper respiratory system agents which are a source of microorganisms capable of being transmitted through saliva, respiratory secretions and blood which contaminate instruments, suction and other implements used in routine clinical practice.

Among the infectious agents involved in oral tissue lesions are viruses, such as the herpetic stomatitis virus, especially the secondary infection as a reactivation of an upper respiratory system infection⁴. Herpes zoster, measles, mumps and varicella, are other diseases caused by viruses.

In relation to bacteria, however there is no evidence of bacterial tuberculosis infection in dentists caused by patient contamination, although this possibility should not be discarded. Tuberculosis is a disease not conquered by the world, there is very serious data to prove how in the United States, for instance, the disease that for three decades showed 6% decrease of incidence per year, now is increasing at 9.4% between 1989 and 1990⁵.

Another factor to be considered refers to the immunological state of patients. Patients affected by immune system diseases such as AIDS, alcoholism or drug abuse favor the multiplication of opportunist pathogenic agents. Also, all systemic diseases or treatments which alter the immune system are an important factor for increased oral infections⁶.

Due to the high risk of routine dentistry practice, the preventive measures taken for the personnel who work at a dental office should include: the use of gloves, face masks, eyewear and uniforms. Masks must be 95 percent effective in filtering particles of 3-5 microns and should be changed after one hour of use. Eyewear must be large enough to protect the eyes from aerosol splashing⁷.

For patient protection different methods of disinfection and sterilization are recommended that should guarantee the control of cross contamination and the risk of infection.

In relation to mouth rinse, there are studies since the 1970's about the use of them as part of normal infection control protocol. At this time its efficiency in the reduction of the total number of microorganisms in the mouth was demonstrated. Consequently, the AHA (American Heart association) recommended the use of mouth rinses as a prophylactic measure in patients with infectious endocarditis risk⁸.

The findings about the effectiveness of mouth rinses, and in this case of Listerine, lets suggest that in a normal program of infection control, a mouth rinse with an oral antiseptic should be included. On the matter, doctors Fine, Mendieta et. al. in 1992 point out, that the effect of antiseptic mouth rinses can not be explained only by their sweeping effect. They state that the primary effect as the antiseptic activity is responsible for bacteria reduction on saliva, and also the residual effect on saliva does not influence the final surviving bacteria count on the sample^9,12.

Listerine, corresponds to the antiseptic category whose action mechanism is related to bacteria protein denaturalization. It also can affect viruses, especially those which are sensitive to organic solvents. For this reason, besides the antibacterial effects of Listerine, other studies have demonstrated the antiviral effect of this antiseptic. It has being proved that mouth rinses with Listerine for thirty seconds (30"), have an antiviral effect against Herpes simple type I and II of 96.3%, and on Influenza virus type of 100%. Regarding other viruses, Rotavirus reduction of 12,2% was observed and an Adenovirus of 14,8%, values that are insignificant to the objective expected by the mouth rinse¹⁰.

Taking into account the results of this pilot study, it can be postulated that if there is an 85% bacterial reduction in saliva, the risk for instrument contamination is reduced, as is the cross contamination risk among patients.

Mouth rinse as an infection control protocol, should be preceded by a well done medical history, and the hepatitis B vaccine, and followed by hand washing and the use of gloves and face masks.

The importance of infection control protocol in dental offices, is emphasized by the number of publications dedicated exclusively to this matter¹¹. The same matter is stressed at dental schools. The AADS (American Association of Dental Schools)has published a document on this matter titled "Clinical Guide for Infections Control", emphasizing the need for following relevant preventive measures to reduce the contamination risk.

CONCLUSION

Although the majority of dental offices use disinfection and sterilization methods for instruments, and also use barrier methods such as the use of gloves, face masks and uniforms, it is evident that a simple and economical method such as the mouth rinse, could increase the effect of other methods used to prevent the risk of contamination during dental practice.

Address

Carlos E. Gomez,DDS Centro Comercial Sancancio Kra. 27 A # 66-30 Consultorio 1017 Manizales,Colombia Fax (68)871766 E-Mail carrique@eccel.com

The Authors have no financial interest on Listerine product. This is only an antiseptic mouth rinse selected for this pilot study.

Authors authorize the ORTHODONTIC CYBER JOURNAL to publish this material.

Carlos E. Gomez,DDS; Hilda M. Villegas, DDS; Dora Cardona R. Mgs

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