06 November 2019

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Geriatric Dentistry: Chlorhexidine against Oral Colonization

Alessandra Abbà

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Poor oral hygiene has been implicated in the development of aspiration pneumonia in frail patients. In fact inadequate oral care can cause colonisation of microbes in the oral cavity. In particular, this type of pneumonia has been associated with an increase in respiratory pathogens in the oral cavity. Chlorhexidine is the oral antiseptic molecule with the most widely used and success for the control of plaque and treatment of gingivitis. Chlorhexidine is an effective agent in reducing oral colonisation and hence the incidence of pneumonia. This study published on Singapore Medical Journal on May 2016, wants to evaluate the effects of chlorhexidine compared to routine oral care in edentulous geriatric patients.

Matherial&Methods 
This randomised clinical trial has been conducted in the geriatric ward of University Malaya Medical Centre. Admissible participants were patients  ≥ 65 years old admitted to the geriatric unit, edentulous with or without dentures and with functional impairment. 90 participants were randomly chosen and a number from 1 to 90 were randomly assigned to them.  
- Bottle A containing chlorhexidine 0.2% was given to the first column of numbers (intervention group)  
 - Bottle B containing thymol was given to the second column of numbers (control group).   Both bottles were similar in appearance, bottle type and size, amount of solution and colour. As this was a double-blind study, patients, nurses and medical laboratory technicians were not aware of the code key. For seven days nurses assigned solutions of 20 mL once daily. Oral cavity evaluation using the Brief Oral Health Status Examination form was performed before each oral care session. Data on medication received and development of aspiration pneumonia was recorded. On day 7, an oral swab was performed to analyze the possible colonisation.

Results 
In the present study, both groups had high counts of oral microbial colonisation at baseline but no significant difference was found between the groups (p = 0.317). At the end of the analysis, 12 patients were lost so 35 patient were available for the control group and 43 for the test group. In the chlorhexidine group, the oral colony count was significantly reduced after oral care compared to the baseline count (p < 0.001) for about 32 (74.4%) patients. On the contrary, results in the control group showed no significant reduction in oral colonisation after oral care with thymol.   Hence, there was a significant difference in oral colonisation between the two groups (p < 0.001) from baseline to post oral care. The results also revealed that oral colonisation in the control group did not differ significantly at baseline and post oral care (p = 0.375). Recorded data showed that the risk of oral bacterial colonisation was nearly three times higher in the thymol group compared to the chlorhexidine group.

Conlcusions 
Chlorhexidine was effective in reducing oral colonisation compared to routine oral care with thymol (p < 0.001).  The use of chlorhexidine 0.2% significantly decreased bacterial oral colonisation and is a recommended device as it represents an easier and more cost-effective alternative for oral hygiene. 

For additional informations: The effect of chlorhexidine in reducing oral colonisation in geriatric patients: a randomised controlled trial