A study on related factors affecting dental fear in preschool children.

This study aims to examine the manifestations of dental anxiety (DA) and its influencing factors during dental visits among preschool children. The data of 166 preschool children who visited the Department of Dentistry of our hospital from April 2021 to April 2023 with oral problems were retrieved. Their DA performance was investigated using the Children's Fear Survey Schedule-Dental Subscale (CFSS-DS). In addition, based on their general data and potential risk factor information, we performed logistic regression analysis to identify the factors influencing DA. Of the 166 questionnaires distributed, a total of 160 valid questionnaires were retrieved. The average CFSS-DS score was 35.57 ± 3.51 points. Sixty-six children had DA, resulting in an incidence rate of 41.25%. The top 5 items with the highest CFSS-DS scores were fear of needles, dentists, tooth extraction, drilling and oral anesthesia. When the 66 children with DA were classified into a DA group and a non-DA group, we observed significant differences in age distribution, dental experience, only child status, general anxiety symptoms, dental condition, family income and specific dental treatment procedures, particularly tooth extraction, between them (p < 0.05). Multivariate logistic regression analysis revealed that preschool children aged ≤4 years, those with prior dental experiences, single-child status, general anxiety symptoms, suboptimal dental health, family incomes below 100,000 yuan/year, and those undergoing specific dental procedures, such as tooth extractions, were independently associated with a higher risk of DA (p < 0.05). The incidence of DA in preschool children is high, and they exhibit substantial fear of needles, dentists, tooth extraction, drilling and oral anesthesia. Preschool children aged ≤4 years, with prior dental experiences, single-child status, the presence of general anxiety symptoms, suboptimal dental health, family incomes below 100,000 yuan/year, and those undergoing dental procedures, particularly tooth extraction, could be more predisposed to DA.

pH and effects on Streptococcus mutans growth of denture adhesives: an in vitro study.

OBJECTIVES: To evaluate the pH and effects on Streptococcus mutans growth of denture adhesives. BACKGROUND: There is little information regarding the pH of contemporary adhesives and their influences on S. mutans growth. MATERIALS AND METHODS: The adhesives tested were Polident® cream, Protefix® cream and Protefix® powder. Samples of each adhesive were added to deionized water to produce solutions of 10.0, 5.0, 2.5 and 1.0% w/v (cream formulations) or 5.0, 2.5,1.0 and 0.5% (powder formulation). The pH values were measured immediately after preparation and at 1-, 2-, 3-, 6-, 12-, and 24-h intervals using a digital pH meter. Streptococcus mutans UA159 was inoculated in the Brain Heart Infusion medium with or without the adhesive extracts (control). Bacterial growth was observed by measuring absorption at 600 nm every 1 h for 12 h using a spectrophotometer. RESULTS: The tested adhesives generally remained relatively pH-stable over 24 h, ranging from 5.5 to 7.0. There were no statistically significant differences in S. mutans growth rates between the extract-treated and control cultures (p>0.5). CONCLUSIONS: Some adhesives produce a pH below the critical pH of hydroxyapatite and may not be suitable for patients with natural teeth. None of the tested adhesives significantly affect S. mutans growth.

A new gcrR-deficient Streptococcus mutans mutant for replacement therapy of dental caries.

BACKGROUND: gcrR gene acts as a negative regulator related to sucrose-dependent adherence in S. mutans. It is constructive to test the potential capacity of mutans with gcrR gene deficient in bacteria replacement therapy. METHODS: In this study, we constructed the mutant by homologous recombination. The morphological characteristics of biofilms were analyzed by confocal laser scanning microscopy. S. mutans UA159 and the mutant MS-gcrR-def were inoculated, respectively, or together for competitive testing in vitro and in rat model. RESULTS: Adhesion assay showed that the adhesion ability of the mutant increased relative to the wild type, especially in the early stage. MS-gcrR-def out-competed S. mutans UA159 in vitro biofilm, and correspondingly coinfection displayed significantly fewer caries in vivo. The former possessed both a lower level of acid production and a stronger colonization potential than S. mutans UA159. CONCLUSION: These findings demonstrate that MS-gcrR-def appears to be a good candidate for replacement therapy.