A Co-Association of Streptococcus mutans and Veillonella parvula/dispar in Root Caries Patients and In Vitro Biofilms.

Root caries in geriatric patients is a growing problem as more people are maintaining their natural teeth into advanced age. We determined the levels of various bacterial species previously implicated in root caries disease or health using quantitative real-time PCR in a pilot study of 7 patients with 1 to 4 root caries lesions per person. Levels of 12 different species on diseased roots compared to healthy (contralateral control) roots were measured. Four species were found at significantly higher levels on diseased roots (Streptococcus mutans, Veillonella parvula/dispar, Actinomyces naeslundii/viscosus, and Capnocytophaga granulosa) compared across all plaque samples. The level of colonization by these species varied dramatically (up to 1,000-fold) between patients, indicating different patients have different bacteria contributing to root caries disease. Neither of the two species previously reported to correlate with healthy roots (C. granulosa and Delftia acidovorans) showed statistically significant protective roles in our population, although D. acidovorans showed a trend toward higher levels on healthy teeth (P = 0.08). There was a significant positive correlation between higher levels of S. mutans and V. parvula/dispar on the same diseased teeth. In vitro mixed biofilm studies demonstrated that co-culturing S. mutans and V. parvula leads to a 50 to 150% increase in sucrose-dependent biofilm mass compared to S. mutans alone, depending on the growth conditions, while V. parvula alone did not form in vitro biofilms. The presence of V. parvula also decreased the acidification of S. mutans biofilms when grown in artificial saliva and enhanced the health of mixed biofilms.

Effect of green marketing mix, green customer value, and attitude on green purchase intention: evidence from the USA.

The undertaken research examines the impact of green attitude, green customer value (e.g., environmental image and perceived value), and green marketing mix (e.g., product, packaging, price, promotion, and place) on green purchasing intention. The research has integrated fundamental theoretical approaches of customers' purchasing such as attitude-behavior context (ABC) theory, signaling theory, and theory of planned behavior (TPB) in the modified conceptual framework. Additionally, this research has also incorporated the green psychological benefits (e.g., nature experience, self-expressive, and warm glow) as mediating construct. The modified conceptual framework also unified green marketing (e.g., environmental advertising and green word of mouth) as moderator to investigate further the connotation between attitude, green customer value, green marketing mix, and green purchase intention. The survey method is used to collect data with a sample size of 896 customers that are well-versed with eco-friendly green products and services from the different urban centers of the USA. The data is analyzed through a structural equation modeling (SEM)-based multivariate approach by using SPSS 26, AMOS 26, and conditional process modeling software. The findings have demonstrated a positive and significant impact of green customer value, green marketing mix, and attitude on the green purchase intention of US customers. The study has further concluded that the green psychological benefits (mediator) and green advertising (moderator) have a significant influence on a relationship between attitude, green customer value (environmental image and perceived value), green marketing mix, and green purchasing intention. The results of this research can be helpful for researchers and academicians to get insight into theoretical approaches to green purchasing, and it can also be helpful for marketers to devise green marketing strategies to gain optimal competitive advantage in the long run.