Changes in Salivary Interleukin-1 Beta Levels Following a Care Worker-Centered Oral Health Care Program Among Residents of Long-Term Care Facilities

Background/Objectives: Older adults residing in long-term care facilities (LTCFs) are at increased risk of poor oral health because of functional dependence and limited access to professional oral healthcare. Although oral healthcare education programs for care workers improve knowledge and performance, evidence of their effects on residents’ biological oral health outcomes remains limited. This study evaluated the effects of a care worker-centered oral healthcare program on oral inflammatory status in LTCF residents using salivary interleukin-1 beta (IL-1β) as an objective biomarker. Methods: A single-group pretest–posttest quasi-experimental study was conducted in two LTCFs in the Republic of Korea. Forty care workers completed a structured oral healthcare education program and provided daily oral healthcare to residents for 4 weeks. Saliva samples were collected before and after the intervention, and salivary IL-1β concentrations were measured using enzyme-linked immunosorbent assay. Changes in IL-1β concentrations were analyzed using the Wilcoxon signed-rank, Mann–Whitney U, and Kruskal–Wallis tests. Results: Thirty-seven residents completed the study. Median salivary IL-1β concentrations significantly decreased from 19.33 pg/mL (interquartile range [IQR], 11.49–34.66) at baseline to 10.78 pg/mL (IQR, 0.65–33.64) after the intervention (Z = −3.764, p = 0.001). Greater reductions were observed among residents with greater functional dependence, whereas limited communication ability or oral care refusal was associated with minimal improvement. Conclusions: A care worker-centered oral healthcare program significantly reduced salivary IL-1β concentrations among older adults residing in LTCFs. Findings support care worker training and highlight the use of salivary IL-1β as an objective biomarker for evaluating oral healthcare interventions.