Frontiers in dental medicine最新文献

[This corrects the article DOI: 10.3389/fdmed.2024.1442887.].

Aims: Cathepsins are essential lysosomal enzymes that maintain organismal homeostasis by degrading extracellular substrates. The inflammatory cytokine interleukin-6 (IL-6) increases the production of cathepsins through the caveolin-1 (Cav-1) and c-Jun N-terminal kinase (JNK) signaling pathways, which have been implicated in the destruction of periodontal tissue. This study investigated the effect of the IL-6/soluble IL-6 receptor (sIL-6R) complex on the extracellular secretion of cathepsins in human gingival fibroblasts (HGFs) and examined the function of extracellularly secreted cathepsins B and L under acidic culture conditions in vitro.

Methods: HGFs were isolated from healthy volunteer donors. The expression of Cav-1 was suppressed via transfection with small interfering RNA (siRNA) targeting Cav-1. The expression levels of cathepsins B and L induced by extracellular IL-6/sIL-6R were measured using western blotting and enzyme-linked immunosorbent assay. Extracellular cathepsin activity following IL-6/sIL-6R stimulation was assessed using a methylcoumarylamide substrate in a fluorescence-based assay. IL-6/sIL-6R-induced expression of cathepsins B and L in HGFs was quantified under inhibitory conditions for extracellular signal-regulated kinase (ERK) 1/2 and/or JNK signaling, both of which are transduction pathways activated by IL-6/sIL-6R. This quantification was also performed in HGFs with suppressed Cav-1 expression using western blotting.

Results: Cathepsins B and L were secreted in their precursor forms from HGFs, with significantly elevated protein levels observed at 24, 48, and 72 h post-IL-6/sIL-6R stimulation. Under acidic culture conditions, cathepsin B activity increased at 48 and 72 h. Cav-1 suppression inhibited the secretion of cathepsin B regardless of IL-6/sIL-6R stimulation, whereas the secretion of cathepsin L was reduced only after 48 h of IL-6/sIL-6R stimulation. Inhibition of ERK1/2 and JNK pathways decreased the secretion of cathepsin B after 48 h of IL-6/sIL-6R stimulation, and JNK inhibition reduced the secretion of cathepsin L under similar conditions.

Conclusion: IL-6/sIL-6R stimulation increased the extracellular secretion of cathepsin B and L precursors in HGFs, and these precursors became activated under acidic conditions. Cav-1 and ERK1/2 are involved in regulating the secretion of cathepsin B precursors.

Background: The prevalence of maxillary lateral incisor agenesis ranges from 1% to 3%, with slight global variability. The unilateral agenesis of the maxillary lateral incisor is often associated with a contralateral tooth with microdontia or a peg shape and can have esthetic, functional, and psychosocial implications for patients. The aim of the present survey was to assess the perceptions of smile aesthetics among orthodontists, general dentists and laypeople on different treatment choices, modifying the initial condition of the right maxillary lateral incisor agenesis and the contralateral peg-shaped tooth.

Methods: A series of 6 photographs of different smile simulations were presented to 109 orthodontic specialists, 109 general dentists and 141 laypeople through an online survey. Each photograph was duplicated and judged from 1 to 10 for 2 different bipolar adjectives.

Results: Statistically significant results were found for all the groups investigated. All three groups preferred the photo that maintained the typical symmetrical 'high-low-high gingival contour. Moreover, both orthodontic specialists and general dentists preferred unilateral mesialization of the canine and conservative rehabilitation of the peg-shaped incisor. In contrast, the laypeople preferred bilateral mesialization of the canines with peg-shaped incisor avulsion.

Conclusion: The normal symmetrical array of the central incisor, lateral incisor and canine had the best aesthetic results for all subjects. Laypeople were more attracted to a symmetrical smile than were the groups of orthodontic specialists and general dentists.

Background: The aim of this study was to evaluate position shifts during sleep of patients with obstructive sleep apnea (OSA) syndrome both with and without the use of a mandibular advancement device (MAD).

Methods: In total, 73 adult Caucasian patients diagnosed with obstructive sleep apnea syndrome confirmed by polysomnography were retrospectively enrolled. Inclusion criteria were as follows: age >20 years, body mass index <34 kg/m², polysomnographic diagnosis of OSA, non-smoker, absence of comorbidities at diagnosis, and treatment with a MAD. Two polysomnographic monitoring were performed: one at the time of diagnosis (T0) and another after 3 months of treatment (T1). The parameters evaluated were the apnea-hypopnea index, oxygen desaturation index, the total number of position shifts, and position shift index (number of shifts per hour). Since the variables failed the normality test, the Wilcoxon test was performed to analyze the correlation between the mean of polysomnographic parameters at T0 and T1. The difference between the T1 and T0 values for each variable was evaluated using Spearman's rho correlation test. Statistical significance was set at p < 0.05.

Results and conclusions: All the parameters, including respiratory and positional measures, were significantly reduced after the use of a MAD compared to the beginning. Spearman's correlation test revealed a relationship between the total number of sleep position shifts and the sleep position shift index with the oxygen desaturation index. However, no significant correlation was observed between the apnea-hypopnea index and the positional values.

Objective: In this paper, we report a case of missing posterior teeth after mandibular fibular flap grafting and implant restoration by means of a digital restorative process, in the hope that the application of digital technology will help the patient to comfortably establish an adapted occlusal relationship.

Case report: A 29-year-old male patient developed a left mandibular ameloblastoma measuring 35 mm × 35 mm × 25 mm, which did not invade the surrounding bone tissue, submandibular gland tissue, or lymph nodes. After resection of an 85 mm mandibular segment, the patient was reconstructed using a gastrocnemius flap transfer. He was then referred to our institution for postoperative dental implant restoration. The restorative process incorporated various digital technologies including a digital facebow, intraoral scanner, extraoral scanner, facial scanner, and CAD/CAM systems. Following 1 year post-implantation, the patient received second-stage implantation alongside autologous dermal allograft (ADM) transplantation; subsequently, a temporary prosthesis was fabricated while employing an electronic articulator to accurately transfer occlusal relationships before finalizing with permanent restorations. The integration of digital technology throughout this restorative process enhanced both precision and comfort.

Conclusions: This case study offers an innovative and efficient clinical approach for addressing dentition defect following mandibular reconstruction via advanced digital methodologies.

Quantum dots (QDs) nanotechnology has gained significant attention in dentistry due to its unique properties, such as fluorescence, antimicrobial activity, and drug delivery potential. This review aims to identify the dental applications most actively incorporating QD technology and to examine the distinctive properties of QDs within Dentistry. Employing the Arksey and O'Malley five-stage framework, a systematic search was conducted across PubMed, EMBASE, and Scopus databases for English-language publications on QDs in dentistry. Scientific contributions were evaluated by analyzing publication volume, research trends, patents, and key areas of investigation. Of the 1,034 studies initially identified, 71 were fully screened, with 22 meeting the criteria for data extraction. Results showed that antimicrobial properties and bone regeneration are the primary focus areas for QDs in dental materials. Stock solutions and resin composites are the most common materials developed, with the studies primarily targeting ofenhancing antimicrobial capabilities and osteogenesis enhancement. Over the last decade, QDs have demonstrated potential in enhancing drug delivery, antimicrobial efficacy, and optical performance in dental materials. Despite their growing prominence, the clinical translation of QD-based technologies remains limited due to a lack of long-term studies.

Schizophrenia is a complex mental condition characterized by the deterioration of thought processes and inappropriate emotional responses. Compared to the general population, individuals diagnosed with schizophrenia have an increased risk of developing various dental diseases, including dental caries, periodontal disease, oral mucosal diseases, and conditions associated with oral resonance. In this context, we propose to establish links between schizophrenia and dental illness, emphasizing the importance of oxidative stress (OS) markers in schizophrenia, and also the role of dental treatments, particularly dental implants. This highlights the urgent need for an intervention program to improve oral health in patients with schizophrenia, including aspects such as prevention and prosthetic treatment. Dental implants can be a favorable option, offering good aesthetic and functional results for treated patients with schizophrenia. Additionally, a carefully developed surgical plan is essential, requiring collaboration between psychiatry, oral and maxillofacial surgery, anesthesiology, and prosthodontics departments.

Objectives: The flexural strength and elastic modulus of rapidly prototyped denture base materials are affected by numerous factors including reinforcement with nanoparticles (NPs) and post-curing duration (PCD), though the effect of these two factors together has been overlooked. The present study tested the effect of nanodiamonds (NDs) or silicon dioxide nanoparticles (SNPs) with various PCDs on the flexural strength and elastic modulus of rapidly prototyped denture base materials.

Methods: To measure the flexural strength and elastic modulus, bar-shaped specimens (64 × 10 × 3.3 mm) were designed and rapidly prototyped using ASIGA and NextDent denture base resins. Each resin (N = 150) was divided into five groups (n = 30) according to NP type and concentrations: pure group as a control without additives, 0.25% NDs, 0.5% NDs, 0.25% SNPs, and 0.5% SNPs. Specimens from each group were further divided into three groups (n = 10) and post-cured for 15, 60, or 90 min, followed by thermocycling for 5,000 cycles. After measuring the flexural strength and elastic modulus using a three-point bending test, a scanning electron microscope was used to analyze the fractured surface. The bonds between the NPs and the resin were tested by Fourier-transform infrared spectroscopy. ANOVA and post hoc tests were used for data analysis (α = 0.05).

Results: The flexural strength increased with prolonged PCD and the highest values for all tested groups were reported at 90 min (P < 0.001). The flexural strength of both materials increased significantly with the addition of NDs and SNPs in comparison to the pure groups (P < 0.05). K-factor ANOVA analysis of the elastic modulus showed that each factor (NP type, PCD, and material type) had a significant effect on the elastic modulus (P < 0.001).

Conclusion: The flexural strength and elastic modulus of rapidly prototyped denture base resin were increased with the addition of NDs or SNPs and when increasing the PCD. Factors including nanoparticle type and concentration, the post-curing duration, and the material type solely or in combination could affect the flexural strength and elastic modulus of prototyped denture base materials.

Objective: The purpose of this study was to investigate the effects of intraradicular moisture conditions and canal morphologies on the filling quality of iRoot SP with single-cone technique in root canals.

Materials and methods: Eighty-four human single-rooted premolars root canals were pair-matched with similar root canal volumes, aspect ratio (AR) curve shapes, and 3D models after micro-computed tomography (micro-CT) scanning to establish baseline consistency. Root canals were then prepared and assigned to 4 experimental groups with respect to the moisture condition tested: (1) Paper point normal drying (2) ROKEO drying (3) Paper point preliminary drying (4) Wet, followed by filling with iRoot SP single-cone technique. The effects of moisture conditions on root filling quality were studied by calculating the volume percentage of voids through micro-CT scanning and the number and score of voids under dental operating microscope (DOM) observation of the cross-sectional slices. Then classified different cross-sectional anatomical morphologies of the root canals based on the AR value and their impact on the volume percentage of voids after root canal filling were evaluated.

Results: Unified the sample baseline through micro-CT pair-matching, both micro-CT and DOM provided complementary information showed that paper point normal drying and ROEKO drying displayed the lowest voids in terms of volume, number and score (P < 0.05) after filling with iRoot SP single-cone technique in root canals. Further analysis revealed that the voids in different segments of the root canal under four moisture conditions ranked as coronal 1/3 > middle 1/3 > apical 1/3 (P < 0.05). In addition, the cross-sectional AR value of the root canal was positively correlated with the volume of voids within each moisture condition(P < 0.05).

Conclusion: The intraradicular moisture conditions and cross-sectional anatomical morphology had significant effect on the filling quality of iRoot SP with single-cone technique.

Background: Periodontitis is caused by the dysbiosis of subgingival plaque, and Treponema denticola is the pathogen associated with this disease. Bacteriocins are involved in interbacterial competition during dysbiosis. In our previous study, three potential bacteriocin ABC transporter genes (tepA1-B1, tepA2-B2, and tepA3-B3) of T. denticola were investigated. Upstream of tepA1-B1, three genes annotated as bacteriocin-type signal domain proteins are located. However, the role of these proteins in T. denticola remains unclear. In the present study, these bacteriocin-type signal domain proteins were characterized to elucidate their putative roles in T. denticola.

Methods: Gene clusters surrounding bacteriocin-type signal domain protein genes were compared in silico. The expression of proteins and transporters was evaluated using real-time quantitative reverse transcription PCR (qRT-PCR). Bacteriocin-type signal domain proteins were detected using immunoblot analysis. The expression of bacteriocin-like proteins was investigated by co-culturing with Treponema vincentii.

Results: The DNA sequences of the bacteriocin-type signal domain protein genes and upstream lipoprotein genes were highly conserved. Expression of the bacteriocin-type signal domain protein and tepA1 was slightly higher in the mid-log phase than in the stationary phase and was reduced upon co-culture with T. vincentii. Bacteriocin ABC transporter gene tepA1 was expressed independently of tepA2 and tepA3. Immunoblot analysis detected bacteriocin-like proteins in culture supernatants. However, bactericidal activity was not detected in the culture supernatant of T. denticola.

Conclusion: Three tandem lipoprotein-bacteriocin-type signal domain protein genes may have originated from duplication. Bacteriocin-type signal domain proteins are expressed under unstimulated conditions and are secreted by T. denticola cells.