Journal of Applied Oral Science最新文献

Objective: To investigate the transcriptomic profile and dysregulated molecular pathways associated with severe periodontitis.

Methodology: Gingival tissues from patients with severe periodontitis (n=11) and periodontally healthy controls (n=11) were compared using RNA sequencing in this cross-sectional study. Differentially expressed genes (DEGs) were identified and analyzed using Ingenuity Pathway Analysis (IPA). Selected DEGs were validated at the protein level via immunohistochemistry (IHC).

Results: A total of 909 DEGs were upregulated and 742 were downregulated in periodontitis versus healthy tissues. Highly upregulated genes included MT-RNR1, MTRNR2L12, pseudogenes, long non-coding RNAs, and immunoglobulins. Downregulated genes included ADGRG7, C6orf15, members of enzyme families, keratin family members, loricrin (LOR), and immune modulators, such as CD207 (Langerin) and DEFB4A. IPA predicted the Wnt/β-catenin pathway as the most upregulated and the IL-17 signaling pathway as the most suppressed canonical pathway in periodontitis. The expression of the level of protein of LOR, Wnt10b, JUN, and FOS was confirmed by IHC.

Conclusion: Dysregulation in key canonical signaling pathways and the altered expression of genes critical to cell chemotaxis, innate immunity, and epithelial barrier integrity seem to play a pivotal role in the pathogenesis of periodontitis.

Objective: This study investigates the role of peroxisome proliferator-activated receptor alpha (PPARα) in regulating macrophage polarization and inflammatory signaling under stimulation by periodontal pathogens.

Methodology: THP-1-derived macrophages were stimulated with Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) in the presence or absence of PPARα agonists fenofibrate and WY14643, or the antagonist GW6471. Protein expression levels of TNF-α, IL-10, and phosphorylated NF-κB were assessed by Western blot. Immunofluorescence staining was used to evaluate IL-10, NF-κB, and CD36 expression. Flow cytometry quantified changes in macrophage polarization markers, including CD14+CD86+ (M1) and CD68+CD206+/CD163+ (M2) populations. THP-1 cells transfected with a secreted embryonic alkaline phosphatase (SEAP) reporter plasmid were treated with Pg-LPS (1 μg/mL) ± fenofibrate (50 μM) to assess NF-κB/AP-1 activity. PPARα reporter cells were treated with increasing concentrations of GW590735 or WY14643 and exposed to TNF-α, LPS, or GW6471+LPS to evaluate PPARα transcriptional activity.

Results: PPARα activation by fenofibrate reduced TNF-α expression in Pg-LPS-stimulated macrophages and attenuated NF-κB signaling via both TLR2 and TLR4 pathways. Fenofibrate significantly increased IL-10 and CD36 expression, inhibited Pg-LPS-induced NF-κB nuclear translocation, and promoted a phenotypic shift from pro-inflammatory M1 to anti-inflammatory M2 macrophages. Moreover, inflammatory stimuli such as TNF-α and LPS suppressed PPARα activity, which could be restored by potent PPARα agonists.

Conclusion: These findings suggest that PPARα activation modulates macrophage polarization and suppresses inflammatory signaling in response to periodontal bacterial antigens.

Background: Temporomandibular disorders (TMDs) comprise a heterogeneous group of musculoskeletal conditions affecting the temporomandibular joint, masticatory muscles, and associated structures. Growing evidence highlights the role of genetic predisposition as a significant contributor to TMD.

Aim: This study aimed to investigate genetic aspects involved in TMDs etiology.

Methodology: A cross-sectional study was conducted with 249 adolescents, of whom 149 were affected by TMD. Genomic DNA was extracted from buccal cells, and single nucleotide polymorphisms (SNPs) in DRD2 (rs6275 and rs6276), ANKK1 (rs1800497), COMT (rs6269 and rs4818), and 5-HTT genes (rs3813034 and 1042173) were analyzed. Allelic and genotypic distribution, haplotype, and diplotype analysis were performed using PLINK software version 1.06. Multifactor dimensionality reduction (MDR) was applied to identify SNP-SNP interactions and generate an interaction graph.

Results: In total, three possible single-locus allele combinations were obtained for haplotype and diplotype analyses (rs6275|rs6276 in DRD2, rs6269|rs4818 in COMT and rs3813034|rs1042173 in 5-HTT), but no associations with TMD were observed (p>0.05). However, MDR analysis for gene-gene interactions revealed a synergistic relationship between rs6275 (DRD2), rs6269 (COMT), and rs1042173 (5-HTT) that predisposes to TMD (p=0.050).

Conclusion: MDR analysis suggests a possible synergistic interaction among SNPs in the DRD2, COMT, and 5-HTT genes that may contribute to TMD susceptibility in adolescents.

Objective: this study evaluated the effects of incorporating 5wt% and 10wt% surface pre-reacted glass-ionomer S-PRG nanoparticles into a polymethylmethacrylate (PMMA) resin on multiple-ion exchange rates following recharge with an S-PRG solution, flexural strength, surface roughness, and hardness.

Methodology: In total, 72 disc-shaped and 32 rectangular specimens were fabricated from PMMA resin containing 0, 5, and 10% S-PRG nanoparticles, and 20% S-PRG microparticles by weight. In total, six-disc specimens per group were tested for surface roughness and hardness using a contact profilometer and the Vickers hardness test, respectively. The remaining discs were immersed in 11 ml of deionized water for 24 hours, followed by an analysis of their aluminum, boron, sodium, silicate, strontium, and fluoride concentrations. They were then recharged with a 10% S-PRG solution for 24 hours, alternating with deionized water for five cycles, before their ion levels were reanalyzed. Rectangular specimens underwent flexural strength testing via the three-point bending method. Data were analyzed using two-way repeated-measures analysis of variance with a significance level of p<0.05.

Results: PMMA resin modified with S-PRG nanoparticles released all ions except aluminum. The 10wt% nanoparticle group showed significantly higher ion release than the 5wt% nanoparticle and control groups. While the initial ion release from the 10wt% nanoparticle was comparable to the 20wt% microparticle, recharge resulted in slower ion release from nanoparticles. Incorporating S-PRG nanoparticles altered the surface characteristics and flexural strength of the resin (which remained within international standards).

Conclusion: Incorporating 5 and 10wt% S-PRG nanoparticles into PMMA resin facilitated the release of boron, silicate, strontium, sodium, and fluoride ions, but not of aluminum ones following recharge with an S-PRG solution and maintained compliance with standards. The 10wt% nanoparticles achieved a balance between enhanced ion release and the physio-mechanical properties required for denture base resins.

Objective: This randomized, parallel-group clinical trial aimed to evaluate the one-year clinical performance of the Beautibond Xtreme adhesive system (Shofu Inc., Kyoto, Japan) applied with different bonding strategies in Class I and Class II posterior restorations.

Methodology: A total of 22 patients (14 female and 8 male, aged ≥18 years) requiring restorative treatment provided 152 teeth with Class I or Class II carious lesions or defective restorations. Restorations were randomly assigned to six groups, including two control groups (Class I and II using the total-etch technique) and four test groups (Class I and II using either the self-etch technique or selective enamel etching). All restorations were performed using Beautibond Xtreme adhesive combined with Beautifill LS composite resin. Clinical performance was assessed at baseline, six months, and one year using modified United States Public Health Service (USPHS) criteria, including anatomic form, marginal adaptation, marginal discoloration, color match, surface texture, secondary caries, postoperative sensitivity, and retention. Randomization was performed with a computer-generated sequence, and two calibrated, blinded examiners (Kappa = 0.84) conducted all evaluations.

Results: No significant changes were observed in anatomic form, color match, surface texture, secondary caries, postoperative sensitivity, or retention over time in any group (p>0.05). However, restorations performed using the self-etch technique showed significant deterioration in marginal adaptation and marginal discoloration from baseline to six months and one year (p<0.05). Significant differences were also observed when comparing these restorations to the total-etch and selective enamel etching groups (p<0.05).

Conclusion: The Beautibond Xtreme adhesive system demonstrated better clinical performance when applied with total-etch or selective enamel etching techniques compared to the self-etch mode for both Class I and Class II restorations after one year of follow-up.

Background: Bisphosphonates are the most widely marketed drugs in the world to treat osteoporosis but their anti-remodeling effect can cause osseointegration to fail.

Objective: this study aimed to evaluate bone quality during peri-implant repair in osteopenic rats, adopting an approach inverse to the conventional one in which prolonged treatment with alendronate sodium was initiated only after the installation of titanium implants.

Methodology: implants were installed in the tibias of 32 rats 14 days after ovariectomy (osteopenia). After 14 days, systemic treatment was initiated by gavage with a saline solution or alendronate. At 28 and 56 days after implantation, the rats received calcein (20 mg/kg, i.m.). They were administered alizarin red (20 mg/kg, i.m.) seven days before euthanasia. Euthanasia occurred in two periods, 42 and 70 post-implantation days.

Results: the highest implant removal torques were observed for the OVX ALE at 70 days (13.35 Ncm) and the OVX SAL at 42 days (11.63 Ncm). The expression of bone remodeling and resorption proteins (OPG/ RANKL) was higher in the alendronate-treated animals. In contrast, osteocalcin and bone sialoprotein were similar between the control and alendronate-treated groups. No parameter showed statistically significant variations (BV, BV.TV, Tb.Th, Tb. N, Tb.Sp, and i.S), with similar measurements between groups. Fluorochrome analysis showed active bone remodeling at the implant interface.

Conclusion: the alendronate treatment stabilized the bone-implant interface over time, suggesting a protective effect against osteoporotic bone loss despite a delayed initial response. In the long term, the group systemically treated with alendronate showed improved bone formation around the implants, outperforming the control group. However, future research is essential to prevent possible negative impacts on osseointegration in patients taking this medication.

Artificial intelligence (AI) is transforming access to dental information via large language models (LLMs) such as ChatGPT and Google Gemini. Both models are increasingly being used in endodontics as a source of information for patients. Therefore, as developers release new versions, the validity of their responses must be continuously compared to professional consultations.

Objective: This study aimed to evaluate the validity of the responses provided by the most advanced LLMs [Google Gemini Advanced (GGA) and ChatGPT-4o] to frequently asked questions (FAQs) in endodontics.

Methodology: A cross-sectional analytical study was conducted in five phases. The top 20 endodontic FAQs submitted by users to chatbots and collected from Google Trends were compiled. In total, nine academically certified endodontic specialists with educational roles scored GGA and ChatGPT-4o responses to the FAQs using a five-point Likert scale. Validity was determined using high (4.5-5) and low (≥4) thresholds. The Fisher's exact test was used for comparative analysis.

Results: At the low threshold, both models obtained 95% validity (95% CI: 75.1%- 99.9%; p=.05). At the high threshold, ChatGPT-4o achieved 35% (95% CI: 15.4%- 59.2%) and GGA, 40% (95% CI: 19.1%- 63.9%) validity (p=1).

Conclusions: ChatGPT-4o and GGA responses showed high validity under lenient criteria that significantly decreased under stricter thresholds, limiting their reliability as a stand-alone source of information in endodontics. While AI chatbots show promise to improve patient education in endodontics, their validity limitations under rigorous evaluation highlight the need for careful professional monitoring.

Objectives: Menopause causes specific hormonal alterations in women that make them more susceptible to salivary changes, such as decreased saliva flow, which can lead to xerostomia, modified taste, and a burning sensation in the mouth. This study aimed to determine which of two treatments-bone marrow-derived mesenchymal stromal cells (BM-MSCs) or estrogen-more effectively ameliorate the postmenopausal degenerative effects on the parotid salivary glands of ovariectomized rats by histological, immunohistochemical, and malondialdehyde (MDA) evaluations.

Methodology: The study specimen involved 70 female albino rats. Group I received saline, and were subdivided into sham-operated and vehicle-treated. Group II was subjected to bilateral ovariectomy and received no treatment. Group III was subjected to bilateral ovariectomy and, one week later, treatment with subcutaneous injections of 1 mg/kg/daily estrogen for 12 weeks. Group IV underwent bilateral ovariectomy and, one week later, received a single intraglandular injection of a BM-MSC solution. At the end of the experiment, the rats were euthanized, and their parotid glands were dissected and processed for H&E stain, caspase 3, and MDA evaluations.

Results: The histological and immunohistochemical findings in Group II showed marked degenerative changes in the parotid gland. However, in Groups III and IV, regeneration was observed following treatment with estrogen and BM-MSCs, respectively. The estrogen and BM-MSCs groups showed significant decrease in MDA levels in the parotid gland relative to the ovariectomized group and nearly comparable to control.

Conclusion: BM-MSCs and estrogen show histological efficacy in regenerating the parotid salivary glands of ovariectomized rats.

Objective: Bioceramic materials are developed based on their biological properties and bioactive potential. NeoSealer Flo (NeoFlo, NuSmile, Houston) is a ready-to-use bioceramic endodontic sealer. The aim of this study was to evaluate the biocompatibility and bioactivity of NeoFlo compared to Bio-C Sealer (BC, Angelus) and AH Plus (AHP, Dentsply).

Methodology: The tissue reaction induced by materials in rat subcutaneous tissues was assessed at seven, 15-, 30-, and 60-days post-implantation (n=6/group). The number of inflammatory cells (ICs), fibroblasts, and osteocalcin (OCN)-labelled cells were recorded. Amorphous calcite was identified using the von Kossa method and polarized light. The data were evaluated using two-way ANOVA followed by Tukey's test, with a 5% significance level. OCN data were submitted to the Kruskal-Wallis test, with Dunn, Friedman, and Nemenyi post-hoc tests.

Results: NeoFlo capsules showed higher number of IC than BC and AHP (p<0.05) in all periods, with a reduction over time, and was considered moderate at 60 days. Moreover, significant reduction in the number of IC and an increase in the fibroblasts was accompanied by an increase in the amount of collagen in the capsules around all materials over time. Immunoexpression of OCN was only observed in the capsules of NeoFlo and BC, but the capsules of BC showed the highest values in all periods (p<0.05).

Conclusion: In the present study, NeoFlo showed lower biocompatibility than BC, however, NeoFlo shows bioactivity in connective tissue.

Background: Amelogenesis imperfecta (AI) encompasses a group of conditions characterized by abnormalities in the development or function of tooth enamel. Clinical manifestations include different forms and degrees of enamel frailty, associated with sensitivity, tooth fractures, stains, abnormal tooth morphology, missing teeth, etc. AI is genetically heterogeneous, with over 70 genes associated with autosomal dominant, autosomal recessive, X-linked, and oligogenic inheritance.

Objective: To identify genetic variants associated with AI in a single family.

Methodology: We describe the clinical findings of a family affected by AI, composed of five individuals: four affected (the father and three daughters) and one unaffected (the mother). The observed segregation pattern suggests a dominant, X-linked inheritance. Genetic variants were screened using whole-exome sequencing. The initial bioinformatic analysis was conducted using Qiagen QCI, and variants were selected based on their presence in all four affected family members and absence in the unaffected mother. Search terms included "amelogenesis imperfecta," "tooth," and "enamel." Several types of software were used to classify variants according to pathogenicity.

Results: Candidate variants were identified in six genes. Three of these variants were detected in autosomal genes: NM_031889.3(ENAM):c.1726T>C (p.F576L), NM_022168.4(IFIH1):c.1764dupA, (p.A589fs*21), and NM_032383.5(HPS3):c.1897A>T (p.M633L). Three variants were detected in X-linked genes: NM_006150.5(PRICKLE3):c.8C>G (p.A3G), NM_004484.4(GPC3):c.584A>G (p.N195S), and NM_152787.5(TAB3):c.1936G>A (p.V646M). None of these variants were classified as pathogenic or likely pathogenic in AI.

Discussion: Among the identified genes, only ENAM has previously been associated with AI; however, IFIH1, PRICKLE3, and GPC3 are associated with dental/enamel development. The relatively high number of candidate genes and variants detected may reflect an oligogenic component already proposed for AI.

Conclusions: This study provides a set of new candidate genes and genetic variants for AI. Despite sharing the same variants, AI-affected family members show considerable phenotypic variant, suggesting the involvement of non-shared genetic or environmental factors.