In a dental operatory, modes of microbial transmission are of three general categories.
1. Direct contact with infectious lesions, blood or saliva.
2. Indirect transmission via transfer of microorganisms by a contaminated intermediate object.
3. Aerosolization via the airborne transfer of infected blood, saliva, or nasopharyngeal secretion droplets.
For infection control, we emphasize seven major areas:
1. Patient screening and evaluation
2. Personal protection
3. Aseptic technique
4. Instrument Sterilization
5. Environmental surface disinfection
6. Equipment asepsis and
7. Laboratory asepsis.
Use of an antiseptic mouth rinse preparation as a routine infection control measure is a comparatively recent method. This procedure will come under aseptic technique for infection control.
Apart from a wide variety of aerobic, facultative and anaerobic bacteria, most adults have been infected with and shed herpes viruses. Unless proper protective measures are adopted, dentists face a constant risk of infection from oral and systemic microorganisms transmitted from the patient’s mouth.
Most of the investigations in quest of clinically useful antiseptic agents have focused on chemotherapeutic substances that affect plaque formation, gingivitis or periodontitis. 0.12% Chlorhexidine demonstrates certain characteristics which dictate its use as a pre-procedural mouth rinse.
The broad antibacterial effect of Chlorhexidine include significant reductions in the numbers of total aerobes and anaerobes.
A significant reduction in the total anaerobic bacterial population within one minute after a single rinse with chlorhexidine has been reported. Continued analysis of the microbial flora has demonstrated a five hour antimicrobial effect. Significant reductions in aerobic and facultative bacteria have been noted even in the presence of bioburden such as blood and debris associated with scaling and root planing procedures.
In vitro studies have demonstrated virucidal activity against herpes simplex virus, cytomegalo virus, influenza A, para influenza, and hepatitis B viruses, in as brief an exposure as 30 seconds.
More about chlorhexidine.
Chlorhexidine has been proven to be the most effective chemical agent for the reduction of plaque and gingivitis.
1. It reduces pellicle formation.
2. It allows bacterial absorption and/or attachment to teeth.
3. Alters bacterial cell wall causing lysis.
4. It has a high degree of substantivity i.e., it adheres to tissues and remain for a long time, increasing its effectiveness in fighting bacteria.
5. Non specific antimicrobial activity of chlorhexidine has not been associated with development of resistance of pathological oral bacteria.
6. Due to its fungicidal action, chlorhexidine may benefit HIV infected people because of their propensity to contract oral candidiasis.
As a mouth rinse to control plaque and gingivitis, it is recommended to be used twice daily. It should not be used within 30 to 60 mts of a tooth paste since most tooth pastes contain sodium laural sulphate, which can deactivate chlorhexidine. Also, stannous fluoride products should always be used after chlorhexidine since stannous ion and chlorhexidine both compete for and occupy the same site on the tooth.
Some side effects of chlorhexidine include staining of teeth reversible desquamation in young children, alteration of taste, and an increase in supra gingival calcified deposits.
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