Dental pulp cells cocultured with macrophages aggravate the inflammatory conditions stimulated by LPS.

BACKGROUND: Pulp inflammation is complex interactions between different types of cells and cytokines. To mimic the interactions of different types of cells in inflamed dental pulp tissues, dental pulp cells (DPCs) were cocultured with different ratios of macrophages (THP-1) or LPS treatment. METHODS: DPCs were cocultured with various ratios of THP-1, then photographed cell morphology and determined cell viability by MTT assay at preset times. Total RNA was also extracted to measure the inflammation marker-IL-6 and IL-8 expressions by RT-Q-PCR. The DPCs and THP-1 were treated with 0.01 - 1µg/ml lipopolysaccharide (LPS) and extract RNA at preset times, and detected IL-6 and IL-8 expression. DPCs were cocultured with various ratios of THP-1 with 0.1 µg/mL LPS, and detected IL-6 and IL-8 expression after 24 and 48 h. The data were analyzed by unpaired t-test or Mann-Whitney test. Differences were considered statistically significant when p < 0.05. RESULTS: THP-1 and DPCs coculture models did not suppress the viability of DPCs and THP-1. Cocultured with various ratios of THP-1 could increase IL-6 and IL-8 expressions of DPCs (p = 0.0056 - p < 0.0001). The expressions of IL-6 and IL-8 were stronger in higher ratio groups (p = 0.0062 - p < 0.0001). LPS treatment also induced IL-6 and IL-8 expressions of DPCs and THP-1 (p = 0.0179 - p < 0.0001 and p = 0.0189 - p < 0.0001, separately). Under the presence of 0.1 µg/mL LPS, DPCs cocultured with THP-1 for 24 h also enhanced IL-6 and IL-8 expression (p = 0.0022). After cocultured with a higher ratio of THP-1 for 48 h, IL-6 and IL-8 expressions were even stronger in the presence of LPS (p = 0.0260). CONCLUSIONS: Coculturing dental pulp cells and macrophages under LPS treatment aggravate the inflammatory process. The responses of our models were more severe than traditional inflamed dental models and better represented what happened in the real dental pulp. Utilizing our models to explore the repair and regeneration in endodontics will be future goals.

Facilitating Green Supply Chain in Dental Care through Kansei Healthscape of Positive Emotions.

Dentistry is highly energy- and resource-intensive with a significant environmental impact. To consolidate green dentistry supply chains, delivering the care of highest quality that meets client value should not be neglected. This study emphasized the importance of client-centered healthscape design for facilitating a green dentistry supply chain. A client-centered healthscape design, which promotes clients' positive emotions and increases willingness to revisit the dentist, plays a critical role in realizing green dentistry supply chains in the long run. For this purpose, the relationship among dental healthscape design elements, client emotions, and revisit intentions was investigated using a Kansei engineering-based approach. The effects of dental healthscape elements on clients' positive emotions and the effects of positive emotions on clients' revisit intentions were holistically examined on the basis of the stimulus-organism-response model. Through this approach, 17 elements of design, ambience, and social interaction factors that comprise the dental healthscape and 20 Kansei words used to express clients' positive emotions regarding dental service were identified. A questionnaire survey was used to assess Kansei and revisit intention in healthscape scenarios, composed of varied design elements. Primary data were collected from 600 individuals from 2017 to 2018 throughout Taiwan. Partial least squares was applied to holistically analyze the effects of dental healthscape elements on clients' positive emotions and the effects of positive emotions on clients' revisit intention to generate a Kansei model for the dental healthscape. All 20 Kansei words had significant positive effects on the dental revisit intention of clients. The five positive emotions most associated with increased revisit intention were thoughtful, hopeful, tender, comfortable, and cozy. The Kansei model of the dental healthscape provides references for healthscape design that maintains positive client emotions during the dental service and results in high revisit intention. This approach can realize an emotion-centered design for dental healthscapes that promotes preventive dental care, early treatment, and effective use of medical resources, and consequently contributes to green dentistry supply chains.