A randomized clinical trial on the effect of a chlorine dioxide spray on dental plaque and respiratory pathogens in institutionalized elders

Abstract

OBJECTIVES: The primary objective of this 6 month study was to compare the effectiveness of oral health promotion interventions on both clinical oral health, and oral opportunistic respiratory pathogens in institutionalized elders. Secondary objectives were to investigate changes in oral health-related quality of life, incidence of adverse side effects, pneumonia, as well as subject acceptability.

METHODS: A total of 228 elders across 11 nursing homes in Hong Kong were recruited into the clinical trial. Patients were randomly allocated into one of the following groups: 0.2% chlorhexidine spray, 0.1% pH-balanced chlorine dioxide spray, or sterile water spray (placebo control), once daily. Dental plaque, gingival bleeding, oral opportunistic respiratory pathogens, oral health-related quality of life (OHRQoL), and pneumonia incidence were assessed at baseline, 3 months and 6 months. Subject acceptability of the interventions was assessed at the end of the clinical trial.

RESULTS: One hundred and forty-two patients were available for review at 3 months. Significantly greater reductions in PI scores were observed in the chlorhexidine spray group compared to the other two groups (p=0.022). Significant reductions in gingival bleeding (GBI) scores were observed among all three treatment groups (p<0.05), with no differences in GBI change scores between groups. Almost one fifth (17.1%) of participants harbored Staphylococcus aureus, while more than a quarter (25.9%) harbored aerobic and facultatively anaerobic Gram-negative bacilli (AGNB) at baseline. The prevalence rate of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis was 0%, 13.2%, and 7%, respectively. No significant changes in the prevalence and viable counts of opportunistic respiratory pathogens were observed within each individual group, or between groups, over the 3-month intervention period (p>0.05). There was no significant change in overall OHRQoL at 3 months (p>0.05).

A total of 135 participants were reviewed at 6 months. Significantly greater reductions in PI scores were observed with the chlorhexidine spray and chlorine dioxide spray, compared to the placebo spray (p=0.016). While significant reductions in GBI scores were observed within each group after 6 months (p>0.05), GBI change scores were not significantly different between groups. No significant differences were observed in the prevalence and viable counts of S. aureus, S. pneumoniae, H. influenzae or M. catarrhalis between groups. The chlorhexidine spray group was observed to have higher prevalence and viable counts of AGNB (p=0.01), poorer OHRQoL in the functional limitation domain (p=0.02), and significantly higher staining scores (p<0.05) compared to the other treatment groups.

CONCLUSIONS: Antimicrobial sprays as part of an oral health promotion program were shown to be effective among institutionalized elders. Chlorine dioxide spray showed equivalent effects on dental plaque and gingival bleeding compared to chlorhexidine spray over the long term6-month period. Higher prevalence and viable counts of AGNB, as well as extrinsic staining, were observed among subjects in the chlorhexidine spray group at 6 months, compared to the chlorine dioxide spray group. Moreover, given that more patients dropped out because of the unfavorable taste of the chlorhexidine spray, chlorine dioxide may be an optimal alternative plaque-inhibitory agent for long-term use.