Karina Gonzales Silvério

This in vitro study evaluated the effects of intracanal medications on the metabolic activity and adhesion of human periodontal ligament‐derived mesenchymal stem cells. Tested groups included Control (without medication), Triple Antibiotic Paste (TAP), Double Antibiotic Paste (DAP), calcium hydroxide with saline, calcium hydroxide with 2% chlorhexidine gel and Bio‐C Temp. After conditioning, roots were stored in phosphate‐buffered saline at 37°C for 21 days. Medications were then removed using 17% EDTA and saline, and dentine samples were used as substrates for cell culture at 3, 5 and 7 days. Metabolic activity was assessed via MTT assay, and adhesion via scanning electron microscopy. None of the medications negatively affected cell viability or adhesion compared to control. TAP showed higher metabolic activity than calcium hydroxide with saline at Day 7. DAP induced earlier cell morphology changes. Bio‐C Temp and chlorhexidine gel showed no significant differences at Day 7, confirming overall biocompatibility.

Background/Objectives: Dental caries remains a prevalent chronic disease globally, driven by complex interactions between the host, diet, and microbial communities. This study employs a metatranscriptomic RNA-Seq analysis to explore the functional dynamics of the dentin microbiome in both healthy and carious teeth. By examining the transcriptional activity of bacterial communities, we aimed to identify key microbial species and molecular functions associated with caries progression. Methods: Samples from six patients (three healthy and three decayed teeth) were analyzed using the Illumina NovaSeq 2000 platform, with data processed through the SAMSA2 pipeline for taxonomic and functional annotation. Results: The differential expression analysis revealed significant upregulation of Streptococcus and Lactobacillus species, including S. mutans, S. sobrinus, and L. salivarius, in carious samples, highlighting their roles in acid production and carbohydrate metabolism. Additionally, Mycobacterium species, known for their biofilm-forming capabilities and acid tolerance, were upregulated in decayed teeth. The Gene Ontology (GO) enrichment analysis identified unique molecular functions and biological processes in carious teeth, such as carbohydrate metabolism, oxidative stress response, and bacterial cell wall biogenesis, which are critical for microbial survival in acidic environments. In contrast, healthy teeth exhibited functions related to homeostasis and nutrient acquisition, reflecting a balanced microbial community. Conclusions: The study underscores the polymicrobial nature of dental caries, with multiple bacterial species contributing to disease progression through diverse metabolic and stress-response mechanisms. These findings provide deeper insights into the ecological shifts within the oral microbiome during caries development, emphasizing the importance of a functional metatranscriptomic analysis in understanding the pathogenesis of dental caries.

Normal wound healing occurs in four overlapping stages - hemostasis, inflammation, proliferation, and remodeling. In the oral cavity, these processes occur in an infectious environment. Among the pathogens found in the oral community, Aggregatibacter actinomycetemcomitans (Aa) constitutes a well-recognized periodontal pathogen responsible for expressing several virulence factors, which activate a host response. Aim: This study investigated whether Aa’s presence can interfere with oral keratinocyte tissue healing in an in vitro wound healing model. Methods: Two groups were defined: Group KO (n=5) and Group KO+Aa (n=5). The Aa (JP2 strains) were cultivated in anaerobiosis, and the total protein extract was obtained. The keratinocytes were cultivated with the medium of standard culture until their confluence. After confluence, plates were allocated to each group. With the pipette’s tip, a “scratch” was made in the middle of each well of the plate, and the cells were cultured at 37°C in a humidified atmosphere with 5% CO2. The cells received the stimulus according to groups, and, at times 0, 5, 10, 24, and 48 hours, the wound areas were visualized and standardly recorded using an inverted microscope. Results: When analyzing the timeframe, differences in wound measurements indicate a faster closure in the control group compared to the KO+Aa group, although not statistically significant. However, upon examining the wound closure measures, it was observed that the Aa protein extract significantly reduced wound closure at 10 and 48 hours (p<0.05), negatively impacting the keratinocyte’s behavior. Conclusion: In summary, it was demonstrated that the pathogen Aa can interfere with the re-epithelization in vitro.

Periodontal dental ligament mesenchymal stem cells (PDLMSCs) play a major role in periodontal tissue regeneration by the neoformation of root cementum and alveolar bone. These cells are highly heterogeneous, and many present low potential to renovate the hard tissue damaged by periodontal disease. A previous study found that the low osteoblast/cementoblast (O/C) differentiation potential of PDLMSCs is related to high asporin (ASPN) expression, which was identified as a negative regulator of PDL cells differentiation and mineralization, suppressing BMP-2-induced O/C differentiation.

Periodontitis Stage III-IV, Grade C (PerioC) is a severe form of Periodontitis. The individual genetic background has been shown to be an important etiopathogenic factor for the development of this disease in young, systemically healthy, and non-smokers patients. Recently, after exome sequencing of families with a history of the disease, PerioC was associated with three single nucleotide variations (SNVs) – rs142548867 (EEFSEC), rs574301770 (ZNF136), and rs72821893 (KRT25) – which were classified as deleterious or possibly harmful by prediction algorithms.

Objective This study aimed to investigate the influence of smoking on clinical, microbiological and immunological parameters in young adult with stage III-IV Grade C periodontitis after full-mouth ultrasonic debridement (FMUD) associated with Amoxicillin and Metronidazole (AMX + MTZ), comparing smokers (PerioC-Y-Smk) with non-smokers (PerioC-Y-NSmk). Materials and Methods Fifteen PerioC-Y-NSmk and 14 PerioC-Y-Smk patients underwent FMUD associated with AMX + MTZ for 10 days. All parameters were collected at baseline and 3 and 6 months after treatment. Plaque index (PI), bleeding on probing (BoP), probing depth (PD), clinical attachment level (CAL)- the primary variable-, and gingival recession (GR) were clinically assessed. The impact of PI on CAL change at 6-month was verified by a regression analysis. Samples of the subgingival biofilm was collected for detection of levels of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P.gingivalis), Tannerella forsythia (T. forsythia), and Fusobacterium nucleatum ssp (F. nucleatum), and were analyzed by real-time qPCR; gingival crevicular fluid was collected for detection of levels of interleukin (IL)-1 beta, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma, which were analyzed using an enzyme immunoassay. Results PerioC-Y-Smk had significantly higher PI, BOP, and GR at baseline compared to non-smokers (p < .05). PerioC-Y-Smk presented higher PD, CAL, and GR at 3 and 6 months (p < .05) compared with PerioC-Y-NSmk in the same periods; PI negatively affected CAL gain in PerioC-Y-NSmk at 6-month follow-up (p = .052) and did not impact on clinical response in PerioC-Y-Smk (p = .882). Lower levels of IFN-gamma, IL1-beta, and IL-4 were observed at 3 months in the PerioC-Y-NSmk (p < .05) compared with PerioC-Y-Smk. Lower proportions of P. gingivalis were observed in PerioC-Y-NSmk at baseline and at 3 months (p < .05) and lower proportions of F. nucleatum were observed at 6 months, in the PerioC-Y-NSmk (p < .05). Conclusions PerioC-Y-Smk presents an unfavorable clinical, microbiological, and immunological response after 3 and 6 months after FMUD associated with AMX + MTZ. Clinical Relevance Smoking worsens periodontal condition of young treated adults presenting stage III/IV Grade C periodontitis.