The Chinese journal of dental research : the official journal of the Scientific Section of the Chinese Stomatological Association (CSA)最新文献

The diagnosis of a facial sinus tract caused by periapical infection remains difficult due to the wide range of potential aetiologies. The canine is the only maxillary tooth that has been reported to serve as the source of infection for a facial sinus tract. The scenario encountered in the present case was extremely rare as the facial sinus tract was caused by the maxillary molar. The buccal alveolar bone of the maxillary right first molar had been destroyed due to periodontitis and aberrant occlusal force, which caused a periapical abscess in the maxillary right first molar site and ultimately drained extraorally. The purpose of this case report is to illustrate the potential for a periapical lesion of the maxillary molar to induce facial sinus tracts and propose a non-surgical therapeutic approach for such cases.

Objective: To evaluate the precision and efficiency of dynamic navigation-assisted trephines and fissure drills at varying depths utilising a 3D printed model.

Methods: A computer-designed in vitro standardised model was 3D printed using photosensitive resin, with hemispherical cavities reserved at depths of 5, 10 and 15 mm from the outer surface of the model. CBCT scans were taken before the procedure, and the data were imported into dynamic navigation software. Navigation paths were planned and executed using a trephine with a diameter of 4 mm and a fissure drill with a diameter of 1.2 mm guided by the dynamic navigation system. Ten procedures were performed at each depth. Postoperative CBCT scans were taken to reconstruct the navigated trajectories, and the platform deviations, end deviations and angular deviations were calculated by comparing the actual paths with the planned paths. The operating time was recorded.

Results: Under the guidance of the dynamic navigation system, the mean platform, end and angular deviations for trephines were 0.34 ± 0.17 mm, 0.25 ± 0.15 mm and 1.02 ± 0.49 degrees, respectively. For fissure drills, the mean deviations were 0.29 ± 0.13 mm, 0.31 ± 0.18 mm, and 1.33 ± 0.98 degrees, respectively. No significant differences were found with different depths or instrument types (P > 0.05). High-speed handpieces with fissure drills showed superior efficiency to low-speed handpieces with trephines (P < 0.001).

Conclusion: Dynamic navigation technology achieved good accuracy within a 15-mm depth range. The use of a trephine or fissure drill did not affect the accuracy of the dynamic navigation technique. High-speed handpieces with fissure drills showed superior efficiency.

Objective: To evaluate the association between systemic diseases and severity of periodontitis based on Chinese epidemiological data.

Methods: Data of dentate subjects (35- to 44-year-old group, 55- to 64-year-old group, and 65- to 74-year-old group) from the Fourth National Oral Health Survey of China were analyzed. Selfreport diagnosis of systemic diseases was based on face-to-face interview. Periodontal status was defined by the 2018 classification scheme and periodontal parameters including bleeding on probing (BOP), probing depth (PD) and attachment loss (AL).

Results: The prevalence of systemic diseases, was much higher in subjects with advanced periodontitis but similar in subjects with other periodontal status. The association between systemic diseases and advanced periodontitis is stronger in the younger adult group but weakens with age.

Conclusion: Periodontitis is a significant associated with systemic diseases, especially hypertension, heart disease, diabetes among Chinese adults based on the data of the Fourth National Oral Health Survey of China. In view of the worsening health burden of periodontitis, it might be necessary for healthcare providers to be more concerned about prevention and treatment of periodontitis in order to enhance systemic health.

Objective: To investigate the biological function of miR-192-5p in osteogenic and odontogenic differentiation of dental pulp stem cells (DPSCs).

Methods: Alkaline phosphatase (ALP) activity assay, Alizarin Red S (ARS) staining and western blot analysis were applied to investigate the osteogenic differentiation potential of DPSCs in vitro. The osteogenic capacity was estimated by subcutaneous transplantation in nude mice in vivo. Carboxyfluorescein diacetate, succinimidyl ester (CFSE) assay was used to examine cell proliferation. Bioinformatics analyses, dual-luciferase reporter assays and real-time reverse transcriptase-polymerase chain reactions (RT-PCR) were applied to explore the regulatory mechanism of miR-192-5p.

Results: miR-192-5p decreased the ALP activity, nodule mineralisation and expression of BSP and OCN in DPSCs, and inhibited cell proliferation. Conversely, the miR-192-5p inhibitor motivated the osteogenic and odontogenic differentiation of DPSCs both in vitro and in vivo, along with promoting cell proliferation. COL5A1 was recognised as the target gene of miR-192- 5p through bioinformatics analysis. Furthermore, dual luciferase reporter assays and RT-PCR experiments confirmed this interaction. Subsequent research verified that COL5A1 knockdown negatively affects the osteo-/odontogenic differentiation of DPSCs, with the PI3K/AKT signalling pathway involved in this process. COL5A1 knockdown promoted the proliferation of DPSCs.

Conclusion: miR-192-5p suppressed osteo/odontogenic differentiation by targeting COL5A1 in DPSCs and negatively regulated their proliferation. Conversely, COL5A1 knockdown promoted proliferation.

Objective: To investigate the causal role of periodontitis in inducing distal-organ aging and elucidate the mechanism between periodontitis and multi-organ aging by assessing the role of NF-κB signalling in mediating cellular senescence.

Methods: A ligature-induced periodontitis mouse model was established to systematically examine the expression profiles of senescence markers, including senescence-associated secretory phenotype (SASP) regulatory genes (Il1b, Il6, Mmp13), telomere length, and cellular senescence markers (p16^INK4a, p21^CIP1/WAF1 and β-galactosidase) in peripheral blood, bone marrow, aorta, heart, thymus and uterus. To further clarify the mediating role of the NF-κB signalling pathway in periodontitis-induced multi-organ aging, an intervention study was conducted using the specific NF-κB inhibitor BAY 11-7082.

Results: The results revealed significantly elevated expression of SASP-related genes in the peripheral blood of periodontitis mice compared to controls (P < 0.01). Various classic molecular hallmarks of aging, such as upregulated expression of SASP genes, shortened telomeres and increased p16 expression, were also observed in multiple distal organs/tissues. Further mechanistic studies revealed that selective inhibition of the NF-κB signalling pathway significantly attenuated the expression of these aging phenotypic markers (P < 0.01), indicating that this pathway plays a critical role in mediating periodontitis-induced systemic aging.

Conclusion: This study provides direct experimental evidence that periodontitis can promote systemic multi-organ aging via activation of the NF-κB signalling pathway, establishing a theoretical basis for developing therapeutic interventions.

Objective: To develop a new alveolar bone morphology classification for maxillary incisors in patients with maxillary protrusion, and to investigate the association of alveolar morphology with skeletal patterns and alveolar bone defects following retraction.

Methods: A retrospective study of CBCT scans was performed for 250 patients with maxillary protrusion. The morphology of alveolar bone around maxillary incisors was classified into four types: A1 (upright maxillary incisor in thin alveolar bone), A2 (lingually inclined maxillary incisor in thin alveolar bone), B1 (upright maxillary incisor in thick alveolar bone) and B2 (lingually inclined maxillary incisor in thick alveolar bone). The association of alveolar types with different skeletal patterns and the incidence of post-treatment alveolar bone defects were analysed.

Results: For maxillary incisors in patients with maxillary protrusion, A1 was the most common alveolar type (33.4%), followed by A2 (28.5%), B1 (22.1%) and B2 (16.0%). Types B1 (34.4%) and A2 (42.2%) were the most common in maxillary central and lateral incisors, respectively. In high angle patients, A2 and A1 were the most common types for maxillary lateral (49.6%) and central incisors (41.2%), respectively. Additionally, types A1 and A2 were at greater risk of severe lingual dehiscence.

Conclusion: This is the first alveolar bone morphology classification for maxillary incisors in patients with maxillary protrusion. The alveolar types exhibited a significant association with skeletal patterns and the incidence of alveolar bone defects after retraction.

Objective: To explore the underlying mechanisms of the association between periodontitis and cognitive impairment.

Methods: Single-nucleus transcriptomics of mice were used to investigate the impact of periodontitis on brain and hippocampal cells to gain insights into disease progression. After data processing, functional enrichment, pathway analysis and cell-cell communication analysis were used to identify the distinct pathways and genes upregulated in Alzheimer's disease (AD) linked to periodontitis. After cell culture, real-time quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to confirm the results.

Results: The present authors identified endothelial inflammation as a key factor in periodontitis-related AD. The findings revealed that the upregulation of Mgll expression in endothelial cells was linked to increased antigen presentation and exacerbated neuroinflammation, potentially worsening AD. Moreover, the present authors elucidated MGLL-2AG-CB2 signalling, through which MGLL activation suppresses CB2 expression and leads to heightened inflammation, while MGLL inhibition restores CB2 levels and mitigates inflammation.

Conclusion: The present study revealed the role of MGLL in linking periodontitis to hippocampal endothelial inflammation and antigen presentation in cognitive impairment. This research will enhance the understanding of how periodontitis impacts cognition and explore potential therapeutic strategies to alleviate periodontitis-associated cognitive impairment.

Objective: To compare the results of non-surgical endodontic retreatment (NSER) applied in a single visit between type 2 diabetes mellitus (DM) patients with teeth with apical periodontitis (AP) and healthy individuals.

Methods: The subjects enrolled were divided into two groups. The type 2 DM group was composed of 26 single-rooted mandibular teeth belonging to 26 patients (aged 45.04 ± 10.13 years; 19 women and 7 men) who did not have any other systemic disease. The control group, meanwhile, consisted of 27 single-rooted mandibular teeth from 27 patients (aged 37.78 ± 12.61 years; 15 women and 12 men) with no systemic disease. Both groups received single-visit non-surgical endodontic retreatment. Periapical radiographs were taken with a parallel technique before NSER and at least 6 months after treatment. Periapical index scores (PAI) for the relevant teeth were recorded. The data obtained were analysed statistically. P 0.05 was considered significant.

Results: In both groups, postoperative PAI values decreased compared to the initial values after NSER treatment applied in a single visit (P 0.05); however, there was no significant difference in the change in PAI values over time between the control and type 2 DM groups (P > 0.05). There was also no significant difference in healing between men and women in both groups (P > 0.05).

Conclusion: Following single-visit NSER in teeth with apical periodontitis, similar treatment outcomes were achieved in patients with type 2 DM and healthy individuals.

The regeneration of oral maxillofacial hard tissues is currently one of the issues of most concern in public health. This complex process involves a variety of cell types residing in a specialised microenvironment known as the adult stem cell niche in living organisms. Within this niche, adult stem cells are considered to play a central role in the regeneration of hard tissues, which undergo rapid proliferation and differentiation into progenitor cells to replace lost tissue, throughout postnatal life. Their fate is tightly regulated by the niche factors secreted by the non-stem niche cells present within the same microenvironment. Over the past decades, the advent of lineage tracing techniques has revolutionised the in vivo study of cell dynamics. Through tissue- and temporally-specific labelling of Cre-expressing cells, this method enables researchers to depict the defined cell fates and differentiation trajectories. The present review summarises the progress made in lineage tracing studies of hard tissue formation cell populations residing in the oral and maxillofacial regions, with a focus on stem cells, progenitor cells and niche cells. The aim is to provide new clues for future research endeavours.

Objective: To assess the impact of incorporating various weight fractions of nanometre-sized particulate fillers on specific properties of microfilled composite resin.

Methods: Microfilled composite resin was prepared by mixing 29 wt.% of resin matrix (BisGMA/TEGDMA) with the 71 wt.% of silane treated particulate fillers (Ø 0.4 µm). Then, various fractions of nanometre-sized (180 nm) fillers (0, 5, 10, 15, 20, 25, 30 and 35 wt.%) were added gradually using a high-speed mixing machine. For each composite resin, flexural properties (n = 8) were evaluated using a three-point bending test on a universal testing machine (ISO standard 4049). Fourier transform infrared (FTIR)-spectrometry was used to calculate the degree of monomer conversion (DC%). Surface microhardess (Vickers) was also determined. Surface gloss was measured before and after polishing (4,000-grit paper). A two-body wear test was performed in a ball-on-flat configuration using a chewing simulator with 15,000 cycles. A non-contact 3D optical profilometer was utilised to measure wear depth. An analysis of variance (ANOVA) was applied to interpret the results statistically, then a post hoc Tukey analysis was performed.

Results: ANOVA revealed that the fraction of nanofillers had a significant effect (P 0.05) on flexural modulus, DC%, microhardness, gloss and wear depth. The group without nanofillers showed the highest DC% (56.6%), gloss after polishing (76.2 GU) and wear resistance (24.2 µm) values, whereas the group with 35 wt.% of nanofillers had the highest flexural modulus (9 GPa) and microhardness (70 VH).

Conclusion: It is beneficial to add nanofillers to microfilled composite resin; however, it is essential to assess the proportion ratio carefully. Optimising all the properties of composite resin at once with just one formulation is challenging.