The subjects in "Routine oral cleaning and professional oral care group" were received about routine oral cleaning and professional oral care.

The subjects in "Routine oral cleaning group" were received only routine oral cleaning, just maintain daily condition.

Besides routine oral cleaning was conducted by caregivers, professional oral care intervention was conducted by dental hygienists, and it included muscle massage, oral cleaning, and oral health education once a week.

Hospitalization prevalence and days of each hospitalization due to pneumonia were collected from medical records by questionnaire.

Total salivary and sputum bacterial concentrations were determined using real-time polymerase chain reaction. Staphylococcus aureus (strain ID: ATCC 29213) was used to create the standard growth curve of bacteria. After overnight culture, the samples were prepared by 5-fold serial dilution with normal saline and plating in a Petri dish to produce 2.5×103 to 3.9×107 CFU/mL of bacteria. Genomic DNA of bacteria was extracted from 1 mL of each bacterial serial solution using the modified standard method, which followed three basic steps: lysis, precipitation, and purification. The DNA extracts were resuspended in 20 µL of distilled water and stored at -80°C until real-time polymerase chain reaction (RT-PCR) amplification. The standard curve of bacterial concentration was generated by the bacterial 16S rRNA gene using a serial dilution of Staphylococcus aureus genomic DNA and StepOnePlus Real-Time PCR System (Applied Biosystems).

Oral health examinations were conducted by two trained dentists, and data on plaque, gingival, and tongue coating indexes were collected by oral examination tables.