Hand motor functions on the presence of red fluorescent dental biofilm in older community-dwelling Koreans

Abstract

Background: The Quantitative Light-induced Fluorescence-Digital (QLF-D) system visualizes old and mature dental biofilm as red fluorescence. Risk factors for poor oral hygiene have been identified, however, few studies have evaluated the relationship between mature dental biofilm and hand motor functions. This study aimed to investigate the effects of two important manual motor functions for object manipulation -handgrip strength and manual dexterity- on the presence of red fluorescent dental biofilm in older community-dwelling Koreans using QLF-D, an optical device that reveals dental biofilm. Methods: This cross-sectional study included 70 Korean participants aged >= 65 years, all of whom completed questionnaires and were tested for handgrip strength and manual dexterity. In total, 840 dental surfaces were photographed using QLF-D, and Delta R-20 values, which reflect mature dental biofilm accumulation, were calculated. The t-test was performed to analyze the differences in the Delta R-20 values according to sociodemographic characteristics, health-related characteristics and hand motor functions, while multiple linear regression analysis was used to investigate the effects of hand motor functions on the Delta R-20 values. Results: Multivariate regression analysis revealed that handgrip strength (beta = -0.294) was the factor most strongly affecting mature dental biofilm accumulation (Delta R-20), followed by tooth-brushing time (beta = -0.262) and manual dexterity (beta = -0.241). Conclusions: Reductions in handgrip strength and manual dexterity were independent risk factors for pathogenic dental biofilm accumulation. The results of this investigation suggest that programs designed to prevent the decline, as well as improve, handgrip strength and manual dexterity might improve the oral hygiene of older adults.