| Sign In to gain access to subscriptions and/or personal tools. |
Professional Oral Health Care Reduces the Number of Oropharyngeal Bacteria
1 Hamamatsu-city Oral Health and Care Center, 2-11-2 Kamoe, Naka-ku, Hamamatsu 432-8550, Japan; Correspondence: * corresponding author, kouku{at}city.hamamatsu.shizuoka.jp
Silent aspiration of oropharyngeal pathogenic organisms is a significant risk factor causing pneumonia in the elderly. We hypothesized that regular oral hygiene care will affect the presence of oropharyngeal bacteria. Professional cleaning of the oral cavity and/or the gargling of a disinfectant liquid solution was performed over a five-month period in three facilities for the dependent elderly. Total oropharyngeal bacteria, streptococci, staphylococci, Candida, Pseudomonas, and black-pigmented Bacteroides species were monitored. The levels of these oropharyngeal bacteria decreased or disappeared after weekly professional oral health care, i.e., cleaning of teeth, dentures, tongue, and oral mucous membrane by dental hygienists. After lunch, gargling with povidone iodine was shown to be less effective than professional oral care. These findings indicate that weekly professional mechanical cleaning of the oral cavity, rather than a daily chemical disinfection of the mouth, can be an important strategy to prevent aspiration pneumonia in the dependent elderly.
Key Words: oropharyngeal bacteria • oral health care • aspiration pneumonia • professional care
Aspiration pneumonia is a major cause of death in the elderly, especially during hospitalization. Elderly individuals with cerebrovascular disease have a depressed swallowing reflex, particularly at night, and might have an increased risk for developing aspiration pneumonia (Pinto et al., 1994). The swallowing and cough reflexes have been reported to be markedly depressed in persons suffering from aspiration pneumonia (Sekizawa et al., 1990; Nakazawa et al., 1993). These individuals also had cerebrovascular disease. A high incidence of silent aspiration during sleep was observed in elderly persons with community-acquired pneumonia (Kikuchi et al., 1994). These phenomena indicate that elderly individuals with cerebrovascular disease, causing deterioration in their pulmonary defense mechanisms, frequently aspirate oropharyngeal bacteria at night and may develop aspiration pneumonia. Dental plaque would seem to be a logical source of the oropharyngeal bacteria that cause infection (Scannapieco and Mylotte, 1996). Poor oral status is often observed in the institutionalized elderly (Simons, 1999). Although these individuals often need help with oral health care, most do not receive a systematic approach to oral health care. In such situations, sustained oral health care for 2 yrs has been shown to reduce the incidence of fever and pneumonia markedly (Adachi et al., 2002; Yoneyama et al., 2002). In both of these studies, oral health care included professional cleaning by dental hygienists once a week. In the latter study, gargling with povidone iodine was also used for some individuals. Neither of these studies evaluated the correlation between the clinical outcome and the changes in oropharyngeal bacteria through the study period. We hypothesized, from these results, that oral health care administered by dental professionals reduces oral bacteria from the oral cavity, and might reduce the quantity of oropharyngeal bacteria that can be silently aspirated to the lower respiratory tract. However, the relationship between oral health care and oropharyngeal bacteria has not been proven bacteriologically. We hypothesized that the presence of oropharyngeal bacteria would be affected by regular oral hygiene. It has not been established how significant mechanical cleaning and/or chemical disinfection of the oral cavity contributes to oral health care. The aim of the present study was to evaluate the longitudinal prevalence of oropharyngeal bacteria in institutionalized dependent elderly after a five-month intervention of professional mechanical cleaning of the oral cavity and/or disinfectant gargling, and to seek an effective method of administering oral health care.
Participants and Facilities For this study, we selected three nursing homes for the dependent elderly in Hamamatsu, Japan (referred to here as facilities A, B, and C). Oral health care by dental hygienists had not been performed in any of these facilities prior to this study. Directors of each facility approved the study protocol. Obtaining written informed consent from all residents was difficult, since many residents suffered from impaired mental and physical conditions. Informed consent was obtained from the directors, acting as representatives of the residents. The content of the study was explained to the residents, and consent was obtained by verbal agreement. When oral health care was performed and examinations made, the residents’ respective caregivers attended as witnesses. Those who refused or were unable to cooperate in the study due to physical/mental conditions, or because they were due to be discharged from the facility, were excluded from the study at the beginning or along the way. The protocol of the present study was reviewed and approved by a project council. Baseline data for all residents—including age, sex, medical history, total febrile days (temperature above 37.5°C) during the preceding 2 mos—and assessment of daily living independence were obtained from their caregivers or nurses prior to oral examination.
Intervention of Oral Health Care
Clinical Examination The number of febrile days for each person and the incidence of aspiration pneumonia were monitored throughout the study period.
Bacteriological Examination of Oropharyngeal Flora
Statistical Analysis
Baseline Data Seventy-two residents in facility A, 70 in facility B, and 60 in facility C received oral examinations at the beginning of the study (Table 1  ). More than half of the participants had a cerebrovascular disorder or cognitive impairment. A high percentage of participants were chair-bound or bed-bound in facilities A and B compared with facility C. Mean numbers of teeth present in residents from facilities A, B, and C were 6.2, 5.2, and 5.3, respectively. Mean numbers of teeth present and mean numbers of decayed teeth, DMFT index, and the edentulous percentage did not differ among the three facilities. However, more residents from facility C wore dentures than did those from facilities A and B. Although slight differences were observed, characteristics between the baseline individuals and the actual individuals completing the study or bacteriological tests were nearly identical. In summary, they had few teeth, and some did not wear dentures.
Among all participants at baseline, mean febrile days per month during the preceding 2 mos were significantly higher in the bed-bound elderly than in the independent persons (Table 2 ). Mean numbers of total oropharyngeal bacteria and streptococci increased as the level of independence was reduced. Total oropharyngeal bacteria in bed-bound participants were significantly greater than in others. Staphylococci and Pseudomonas were also detected more frequently in bed-bound participants than in others, but this was not significant.
Changes in Oral Status during Oral Health Care By the end of the study, 62, 59, and 41 persons had received oral health care and had undergone oral examinations over 5 mos in facilities A, B, and C, respectively. Some persons dropped out due to refusal and/or difficulty in receiving oral care. (Details are given in Appendix 3.) In dentate participants, probing pocket depth and debris index were analyzed in those who could receive 6 successive oral examinations. In facility A, pocket depth and debris index, which were evaluated in 27 participants, gradually decreased over 4 mos after the individuals received oral care. Decreases were significant from the 2nd to the 5th months compared with baseline (Fig. 1 ). In facility B (n = 21), pocket depth significantly decreased at the 3rd month, which is one month after the dental hygienist began to perform oral care. However, debris index did not change significantly during the five-month period. In facility C (n = 15), pocket depth and debris index did not change significantly during the five-month period.
Changes in Oropharyngeal Flora during Oral Health Care In facility A, 24 of 30 residents were able to receive successive bacteriological tests and weekly oral health care throughout the five-month period. The mean numbers of total bacteria and streptococci gradually decreased up to the 5th month (Fig. 2A-1 ). Total bacteria at the 3rd month and streptococci at the 4th month were significantly lower compared with levels at the beginning of the study. Percent detection of staphylococci, Candida, Pseudomonas, and black-pigmented Bacteroides species had almost reached zero by the 5th month (Fig. 2A-2).
In facility B, 24 residents received successive bacteriological tests over 5 mos and weekly oral health care over the latter 3 mos. During the first 2 mos, when the residents did not receive oral care, the levels of total bacteria and streptococci did not differ significantly from baseline (Fig. 2B-1  ). The changes in the percent detection of staphylococci, Candida, Pseudomonas, and black-pigmented Bacteroides species were not uniform during the first 2 mos (Fig. 2B-2). After professional care began, total bacteria and streptococci levels decreased significantly up to the 5th month. The percent detection of staphylococci, Candida, Pseudomonas, and black-pigmented Bacteroides species also decreased after oral care intervention began.
In facility C, 19 residents received successive bacteriological tests, and gargled daily over 5 mos, with weekly oral care during the last 3 mos. During the gargling period, levels of total bacteria decreased significantly at 2 mos compared with baseline. However, levels of streptococci did not change significantly (Fig. 2C-1
Changes in Febrile Days per Month and Incidence of Aspiration Pneumonia
Poor oral health is a major risk factor for aspiration pneumonia in older adults (Terpenning, 2005). In this study, residents in three facilities had poor oral health status. The initial debris indices were over 2 in all facilities, and a greater amount of oropharyngeal bacteria and an increased number of febrile days were observed in the persons with low levels of daily living activities. After the implementation of a professional oral health care regime, the debris index decreased in facility A, but not in facilities B and C. This difference might be the result of the monthly oral examination that was performed one week after the last professional care, or due to the shorter oral care period. However, the oropharyngeal bacteria decreased or disappeared in every facility after professional care. Our results confirmed that the cleaning of the oral cavity could affect the reduction of oropharyngeal bacteria, no matter how the course of clinical parameters varies. The levels of Staphylococcus aureus, Pseudomonas, and other periodontal pathogens have been related to the incidence of aspiration pneumonia (Finegold, 1991; Terpenning et al., 2001). Suppression of oropharyngeal bacteria, including the above-named species, could lower the risk of aspiration pneumonia. Our results support the fact that oral health care reduced pneumonia in older persons in nursing homes (Adachi et al., 2002; Yoneyama et al., 2002). This study was performed from the autumn to winter. In facility B, there were significantly more mean febrile days during the oral health care period than during the preceding 2 mos. Generally, elderly people catch cold easily and become feverish in winter. Our study period was too short for us to draw any conclusions on the relationship between oral health care and febrile days or aspiration pneumonia. In both the Adachi et al.(2002) and Yoneyama et al.(2002) studies, the prevalence of fevers did not differ between the oral care group and the non-oral care group within the first 6 mos after the onset of professional care. We did not control for systemic antibiotic use and any underlying respiratory disease among the participants. Some of the participants took antibiotics during the study period. Therefore, we analyzed the bacteriological data in those who did not take antibiotics (facility A, n = 14; facility B, n = 16; facility C, n = 13) during the study period. The reduction patterns of bacteria after residents received professional care were almost the same in each facility. Professional cleaning of the oral cavity in the institutionalized elderly would be less risky and less expensive than the use of antibiotics, because oral health care does not cause problems such as superinfection or the emergence of antibiotic-resistant organisms. Hospitalization due to aspiration pneumonia caused by poor oral hygiene is more expensive as compared with prevention by professional care. Furthermore, according to the results of changes in levels of oropharyngeal bacteria in facility C, chemical disinfection alone proved to be less effective in eradicating oropharyngeal bacteria than professional mechanical cleaning. Chemical agents barely penetrate the full depth of bacterial biofilm, such as dental plaque (Costerton et al., 1999). One strategy for the prevention of aspiration pneumonia is pharmacological therapy with capsaicin, ACE inhibitors, or dopamine (Yamaya et al., 2001). Such pharmacological therapy targets improvement of the impaired swallowing and cough reflex to prevent silent aspiration. In contrast, the cleaning of teeth after every meal for 1 month improved the swallowing reflex and the ability to perform the activities of daily living among elderly nursing home residents (Yoshino et al., 2001). Since oral health care is as effective as pharmacological approaches in improving the swallowing reflex, dental professionals must make an effort to inform medical doctors, nurses, and caregivers of dependent elderly regarding the effectiveness of professional oral health care.
This study was supported by Health and Welfare Sciences Research Grants of Japan.
A supplemental appendix to this article is published electronically only at http://jdr.iadrjournals.org/cgi/content/full/87/6/594/DC1. Received for publication August 5, 2006. Revision received November 9, 2007. Accepted for publication February 11, 2008.
Journal of Dental Research, Vol. 87, No. 6,
594-598 (2008)
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
|
|
 |
|
Sign In to gain access to subscriptions and/or personal tools.
TOP
ABSTRACT
INTRODUCTION
