Animal models and related techniques for dentin study.

The intricate and protracted process of dentin formation has been extensively explored, thanks to the significant advancements facilitated by the use of animal models and related techniques. Despite variations in their effectiveness, taking into account factors such as sensitivity, visibility, and reliability, these models or techniques are indispensable tools for investigating the complexities of dentin formation. This article focuses on the latest advances in animal models and related technologies, shedding light on the key molecular mechanisms that are essential in dentin formation. A deeper understanding of this phenomenon enables the careful selection of appropriate animal models, considering their suitability in unraveling the underlying molecular intricacies. These insights are crucial for the advancement of clinical drugs targeting dentin-related ailments and the development of comprehensive treatment strategies throughout the duration of the disease.

Treatment of type III dens invaginatus in bilateral immature mandibular central incisors: a case report.

BACKGROUND: Dens invaginatus (DI) is a developmental anomaly, Oehlers Type III DI is the most complex type and early diagnosis and treatment is complicated and challenging. This report presents a rare case of a type IIIb DI associated with a periapical lesion in bilateral immature permanent mandibular central incisors. CASE PRESENTATION: An eight-year-old boy referred to our clinic manifesting with pain along with swelling in the mandibular incisors for the past one month. Radiographic examination showed periapical radiolucency exhibiting a scantly defined border, as well as an invagination which had a central invaginated canal extending from the pulp chamber throughout the apical foramen in both mandibular central incisors. We performed two different treatment procedures on the basis of the condition of the main pulp of the mandibular central incisors. in which only the invagination root canal was treated in the right mandibular central incisor, while the invagination and main root canals were treated in the left mandibular central incisor. During the 18-month follow-up period, the teeth were clinically asymptomatic. Imaging examinations indicated complete healing of the periapical lesion and revealed that the wall of the root canal was thickened and the open apex was closed. CONCLUSION: For young permanent teeth with type III Dens invaginatus, it is particularly important to keep pulp vitality, which could maintain root development and allow a good long-term prognosis.

Adhesive Ability of Different Oral Pathogens to Various Dental Materials: An In Vitro Study.

Introduction: In dental treatments, the reason for secondary caries and the failure of root canal treatment is the microbial infection, which concerns most dentists. The challenge of how to reduce the number of bacteria at the filling materials and the number of residual bacteria in the root canal has become a research hotspot. In this study, the bacterial adhesion properties of several common dental materials were compared to provide a theoretical basis for the selection of antibacterial properties of dental materials. Methodology. Three commonly used dental restorative materials and five sealers in root canal treatment were selected. Each material block was immersed in the corresponding supragingival (Streptococcus mutans and Actinomyces viscosus) or subgingival (Porphyromonas gingivalis and Enterococcus faecalis) bacterial solution and cultured under anaerobic conditions at 37°C for 2, 4, 6, 8, 12, 16, 20, and 24 h. The adhesion of bacteria was observed, and the number of different bacteria adhering to various material model disks was calculated at different time intervals under a scanning electron microscope. The adherent CFU load of the materials was determined by colony counting. Results: Streptococcus mutans and Actinomyces viscosus exhibited the strongest adhesion ability to the resin material blocks. Porphyromonas gingivalis and Enterococcus faecalis exhibited the highest adhesion ability to the AH-Plus sealer block. Conclusions: In dental treatments, dental materials should be selected based on the chemical, physical, and biological properties of materials. In addition, it is necessary to develop new antibacterial dental materials.

In vivo Microbial Diversity Analysis on Different Surfaces of Dental Restorative Materials via 16S rDNA Sequencing.

BACKGROUND This study aimed to provide precise material selection guidance for proper clinical restoration and treatment of plaque-related oral diseases, such as dental caries and periodontal diseases. MATERIAL AND METHODS Four groups (n=24) of restorative material sheets (n=24) were prepared using 3M Z350 composite resin (ZR), zinc phosphate cement (ZPC), glass-ionomer (GI), and ICON permeable resin (IPR). Six volunteers wore a plaque-collection device equipped with the 4 restorative material sheets for 48 hours. Plaque samples were collected, and Miseq sequencing was applied to obtain template DNA fragments for microbial diversity analysis. The data were analyzed with nonparametric tests. RESULTS The microbial diversity on the ZPC surface was significantly lower than that on GI and IPR surfaces. The abundance of Firmicutes and Streptococcus on the ZPC surface was significantly higher than on the surfaces of GI and IPR. In contrast, the abundance of Porphyromonas on the surface of ZPC was significantly lower than that on GI and IPR surfaces. (P<0.05). CONCLUSIONS The results of the present study might serve as a basis for material selection under different oral microbial conditions to provide more accurate treatments and restorative procedures in the oral cavity.

Ionic Liquid-Polypyrrole-Gold Composites as Enhanced Enzyme Immobilization Platforms for Hydrogen Peroxide Sensing.

In this work, three different aqueous solutions containing imidazole-based ILs with different alkyl chain lengths ([Cnmim]Br, n = 2, 6, 12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [C12mim]Br-PPy (C12-PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, C12-PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained C12-PPy-Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel C12-PPy-Au-HRP/GCE biosensor for H2O2 detection. The results showed that the prepared C12-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors.

Dental caries and associated factors in 3 to 5-year-old children in Zhejiang Province, China: an epidemiological survey.

BACKGROUND: Dental caries in preschool children is prevalent worldwide, but data regarding its magnitude and associated factors were not available for preschool children in Zhejiang Province, China. This study examines the dental caries situation and its associated factors in Zhejiang Province. METHODS: A total of 1591 children aged 3-5 years and their parents or caregivers were enrolled in this study. The condition of their teeth was assessed by three dental technicians qualified to WHO 2013 criteria. A structured questionnaire was completed by the children's parents or caregivers. A logistic regression analysis was used to analyze the risk factors that may be associated with dental caries occurring among preschool children. RESULTS: Caries prevalence (dmft> 0) of 3-5 year old children in Zhejiang Province was 70.4%. The mean decayed, missing and filled teeth (dmft) scores of the 3, 4 or 5 year old children surveyed were 2.96 ± 4.07, 4.42 ± 4.66, and 5.75 ± 5.19 respectively. The negative binomial regression model found that higher dental caries prevalence was found in children as age increased, with lower body mass index (BMI), with longer breastfeeding duration and with fewer hours of sleep. CONCLUSIONS: The dental caries prevalence and dmft score of 3-5-year-old children in Zhejiang Province was high, and it was associated with age, BMI, breastfeeding duration and hours slept.

Effect of Probiotic Lactobacilli on the Growth of Streptococcus Mutans and Multispecies Biofilms Isolated from Children with Active Caries.

BACKGROUND The purpose of this investigation was to evaluate the effect of probiotic lactobacilli on Streptococcus mutans (MS) and multispecies biofilms isolated from children with severe caries. MATERIAL AND METHODS Twenty children with active caries (DMFS ≥6) were selected as the experimental group and Streptococcus mutans (MS) were isolated from their saliva. After identification the MS strains were mixed with lactobacilli at 37°C, following which viable MS colonies were counted. At the same time dental plaques from the children were mixed with lactobacilli in vitro to form biofilms, and the population of nine common strains in the biofilms was enumerated after 24 hours of growth. RESULTS Lactobacillus casei Shirota, L. casei LC01, L. plantarum ST-III and L. paracasei LPC37 all had strong inhibitory effects on the majority the MS isolated from children with active caries, with the inhibition rate reaching approximately 70-90% (p<0.05). L. casei Shirota, L. casei LC01, L. plantarum ST-III, L. paracasei LPC37 also significantly reduced the numbers of MS, Streptococcus spp., S. sanguinis and total bacteria in mixed biofilms compared with the control group (p<0.05). CONCLUSIONS The four strains of lactobacilli were able to inhibit the growth of Streptococcus mutans and had effects on the composition of bacterial biofilms in vitro. Ingestion of probiotics may be a promising method of caries prevention.

Effect of S. Mutans and S. Sanguinis on Growth and Adhesion of P. Gingivalis and Their Ability to Adhere to Different Dental Materials.

BACKGROUND Caries and periodontal diseases are caused by the biofilm formed by caries- and periodontal disease-related bacteria. Specific biofilms could be formed on different filling materials in oral cavity. Thus, to explore the inhibition effect of restorative filling materials on biofilm formation is of great significance in the treatment of caries and periodontal disease. MATERIAL AND METHODS The supernatants of S. mutans, S. sanguinis, and P. gingivalis suspension were combined with BHI broth. After 24 h, the live P. gingivalis number was calculated by colony counting and the biofilm was monitored by fluorescence microscopy. To test the adhesive ability of S. mutans and S. sanguinis on different dental materials, the biofilm was formed on different dental materials and then the bacterial number was calculated by using a Spectramax 250 microplate reader at OD 550, and the adhesive ability of S. mutans and S. sanguinis on different dental materials was analyzed by scanning electron microscopy. RESULTS The growth and biofilm formation of P. gingivalis was significantly inhibited by S. mutans and S. sanguinis supernatants (P<0.05). All groups except the zinc phosphate cement group (B) exerted a strong inhibitory effect on the biofilm formation of S. mutans and S. sanguinis (P<0.05). CONCLUSIONS The supernatants of S. mutans and S. sanguinis significantly inhibited the growth and biofilm formation of P. gingivalis, and the adhesive ability of S. mutans and S. sanguinis are different on different dental materials. These results provide useful information on dental caries, periodontal disease, and dental materials.

The positive impact of targeted modulating food intolerance on immune-related recurrent pregnancy loss.

BACKGROUND: It has been proven that immune disorders are one of the vital risk factors of recurrent pregnancy loss (RPL), and the presence of food intolerance seems to play an essential role in this. However, the impact of immune status induced by food intolerance on RPL has not been reported. This study utilized a targeted diet avoiding food intolerance as much as possible for each participant to investigate their effects on pregnancy outcomes in RPL patients with positive autoimmune markers. METHODS: From January 2020 to May 2021, fifty-eight patients with RPL were enrolled. They were divided into two groups based on the presence of autoantibodies: the autoantibody-positive group (AP, n = 29) and the autoantibody-negative group (AN, n = 29). Their food-specific immunoglobulin (Ig) G antibodies for 90 foods were tested using enzyme-linked immunosorbent assay (ELISA). The levels of immune parameters and the presence of gastrointestinal discomforts (diarrhea or constipation, eczema, and mouth ulcers) were recorded before and after dietary conditioning, followed by the analysis of pregnancy outcomes. RESULTS: Compared to the AN group, the patients in the AP group showed immune disorders at baseline, such as reduced levels of IL-4 and complement C3, and increased levels of IL-2 and total B cells. These parameters within the AP group were significantly improved after dietary conditioning that avoided food intolerance, while no significant changes were observed in the AN group. Patients in the AP group had significantly higher food-specific IgG antibodies for cow's milk (89.66% vs. 48.28%, p < .001), yolk (86.21% vs. 27.59%, p < .001), bamboo shoots (86.21% vs. 44.83%, p < .001) compared to those in the AN group. Additionally, gastrointestinal discomforts including diarrhea or constipation, eczema, and mouth ulcers were more common in the AP group than in the AN group. After 3-month dietary conditioning, these significantly improved characteristics were only observed in the AP group (p < .001). Finally, the baby-holding rate was higher in the AP group compared to the AN group (p < .05). CONCLUSIONS: The RPL patients in the AN group did not exhibit immune disorders, whereas those in the AP group experienced immune disorders and gastrointestinal discomforts. For patient with positive autoantibodies, dietary intervention may mitigate immune disorders and gastrointestinal discomforts, presenting a promising approach to enhance pregnancy outcomes.

Interaction between microorganisms and dental material surfaces: general concepts and research progress.

Bacterial adhesion to dental materials' surfaces is the initial cause of dental materials-related infections. Therefore, inhibiting bacterial adhesion is a critical step in preventing and controlling these infections. To this end, it is important to know how the properties of dental materials affect the interactions between microorganisms and material surfaces to produce materials without biological contamination. This manuscript reviews the mechanism of bacterial adhesion to dental materials, the relationships between their surface properties and bacterial adhesion, and the impact of bacterial adhesion on their surface properties. In addition, this paper summarizes how these surface properties impact oral biofilm formation and proposes designing intelligent dental material surfaces that can reduce biological contamination.

Separated root tip formation associated with a fractured tubercle of dens evaginatus: A case report.

BACKGROUND: Several previous studies have reported an unusual root formation in which a fractured apical fragment of an immature root continued to develop independent of the main root after trauma to an immature tooth. To date, there have been only rare reports of the continuing apical formation of the fractured root associated with dens evaginatus (DE). This paper presents a case of a separated root tip formation associated with a fractured tubercle of DE. CASE SUMMARY: An 11-year-old boy was referred for gingival sinus on the buccal side of the right mandibular second premolar (tooth # 45). Clinically, tooth # 45 was free of caries, but there was a sign of a fractured tubercle of DE on the occlusal surface. Radiography showed that the root canal of tooth # 45 was widely radiolucent. A separated root apex was found apically under the main root and was nearly completely formed with an apical orifice at the apical tip. Tooth # 45 was diagnosed as tubular fracture of DE with chronic apical periodontitis. A revascularization technique was recommended to treat the tooth. At 3-mo and 1-yr follow-up, the patient remained asymptomatic. Periapical radiography revealed that the separated root tip distally drifted with closure of the apex. However, the root length and thickness of the main root did not increased. CONCLUSION: Clinicians should be aware that even if tubercle of DE is fractured in an immature tooth, the root tip may be separated from the main root and completely formed.

Profiling of Oral Microbiota in Early Childhood Caries Using Single-Molecule Real-Time Sequencing.

Background: Alterations of oral microbiota are the main cause of the progression of caries. The goal of this study was to characterize the oral microbiota in childhood caries based on single-molecule real-time sequencing. Methods: A total of 21 preschoolers, aged 3-5 years old with severe early childhood caries, and 20 age-matched, caries-free children as controls were recruited. Saliva samples were collected, followed by DNA extraction, Pacbio sequencing, and phylogenetic analyses of the oral microbial communities. Results: Eight hundred and seventy six species derived from 13 known bacterial phyla and 110 genera were detected from 41 children using Pacbio sequencing. At the species level, 38 species, including Veillonella spp., Streptococcus spp., Prevotella spp., and Lactobacillus spp., showed higher abundance in the caries group compared to the caries-free group (p < 0.05). The core microbiota at the genus and species levels was more stable in the caries-free micro-ecological niche. At follow-up, oral examinations 6 months after sample collection, development of new dental caries was observed in 5 children (the transitional group) among the 21 caries free children. Compared with the caries-free children, in the transitional and caries groups, 6 species, which were more abundant in the caries-free group, exhibited a relatively low abundance in both the caries group and the transitional group (p < 0.05). We conclude that Abiotrophia spp., Neisseria spp., and Veillonella spp., might be associated with healthy oral microbial ecosystem. Prevotella spp., Lactobacillus spp., Dialister spp., and Filifactor spp. may be related to the pathogenesis and progression of dental caries.

Platelet aggregation promoted by biofilms of oral bacteria and the effect of mouth rinses in vitro.

INTRODUCTION: The purpose of this study was to observe platelet aggregation promoted by biofilms of Streptococcus sanguinis and Porphyromonas gingivalis and to evaluate the effect of two different mouth rinses on this process. METHODOLOGY: In the first experiment, the same amount of S. sanguinis, P. gingivalis, and the S. sanguinis + P. gingivalis mixed solution was added to an equivalent amount of platelet-rich plasma (PRP). Aggregation was measured using a recording platelet aggregometer. In the second experiment, S. sanguinis, P. gingivalis, S sanguinis + P. gingivalis mixed solutions were pretreated with either Listerine antiseptic mouth rinse or Xipayi mouth rinse for 3 minutes, 6 minutes, and 10 minutes, respectively. The same amount of solution was added to the PRP, and the inhibition of aggregation was measured. RESULTS: In the first experiment, S. sanguinis and P. gingivalis were able to induce platelet aggregation. The aggregation rate of S. sanguinis + P. gingivalis was significantly lower than that of either S. sanguinis or P. gingivalis. In the second experiment, when S. sanguinis, P. gingivalis, and the S. sanguinis + P. gingivalis mixed solutions were pretreated with Listerine antiseptic mouth rinse for 3 minutes and Xipayi mouth rinse for 10 minutes, there was no significant platelet aggregation. CONCLUSIONS: Platelets could adhere to S. sanguinis or P. gingivalis, but when S. sanguinis was mixed with P. gingivalis, the aggregation rate was reduced significantly. Treatment with Listerine antiseptic mouth rinse or Xipayi mouth rinse inhibited the ability of the bacteria to induce platelet aggregation.