Journal of Periodontal and Implant Science最新文献

Purpose: The junctional epithelium (JE) covers the cervical areas of developing or existing teeth. It can re-establish itself even after being removed during periodontal therapies, followed by wound healing. However, the mechanisms that can maintain this universally conserved structure are still unclear.

Methods: The molecular mechanisms of JE homeostasis were investigated by altering levels of JE-specific genes in a telomerase immortalized human gingival epithelial cell line (TIGKs) by exposing TIGKs to conditioned medium (C-CM) from cultivated human cementoblasts. The mRNA and protein levels of JE-associated genes in TIGKs were examined using real-time polymerase chain reaction (PCR) and immunocytochemistry (ICC) after treatment with C-CM. The candidate pathways related to differential mRNA and protein expression were analyzed with a DNA microarray and identified using Kyoto Encyclopedia of Genes and Genomes and WikiPathways. Real-time PCR and ICC were conducted to confirm the changes in the expressions of candidate genes.

Results: mRNA levels and protein expressions of amelotin (Amtn) were upregulated after treatment with C-CM for 48 hours. DNA microarray analyses identified 595 genes that were upregulated >2-fold, and 820 genes that were downregulated >2-fold. C-CM promoted the expression of suppressor of cytokine signaling 3 and reduced the expression of an inactivator of Janus kinase 2. Both signaling molecules were found, using siRNA technology, to mediate the increase of Amtn mRNA and protein expression levels.

Conclusions: The upregulation of Amtn in gingival epithelial cells by C-CM suggests that this regulatory pathway is associated with the homeostasis of JE structures by the cementum.

Purpose: This study was performed to evaluate the effects of flap design, grafting material, and graft dimension on flap tension and the initial volume increase achieved in soft tissue augmentation.

Methods: Six fresh porcine jaw cadavers were used in this study. Each side of the jaw was randomly assigned to receive either a standard split-thickness flap or a split-thickness flap with a palatal island. Following flap preparation, random allocation was employed to determine the order of 4 treatment modalities: 3 mm of a volume-stable collagen matrix (VCMX), 6 mm VCMX, 3 mm of a subepithelial connective tissue graft (SCTG), and 6 mm SCTG. Flap tension was measured and the wound was closed after the insertion of each specimen. Intraoral scans were taken before flap preparation and after closure to facilitate profilometric analysis.

Results: The palatal island flap exhibited significantly greater overall (P=0.010) and crestal (P=0.007) volume gains compared to the split-thickness flap, regardless of the use of VCMX or SCTG. The palatal island flap was associated with significantly lower flap tension force values (0.6 N; P=0.035) than the split-thickness flap. Both materials (VCMX and SCTG) demonstrated comparable volume gains.

Conclusions: The findings of this cadaveric study indicate that the use of a palatal island flap effectively reduces flap tension. While both materials (VCMX and SCTG) yielded similar increases in volume, the palatal island flap demonstrated greater volume gains than the split-thickness flap for each grafting material.

Purpose: Fusion of molar roots is a common variation of root morphology known to adversely affect periodontal disease prognosis. Among methods for inducing experimental periodontal disease in animal models, the ligature-induced periodontitis (LIP) mouse model is most frequently employed. However, few studies have examined root abnormalities in experimental mice. This study aimed to investigate the incidence of root fusion in the maxillary second molars of mice and determine its relationship with alveolar bone loss, offering new insights into animal LIP models.

Methods: From 2019 to February 2024, 222 Institute of Cancer Research mice (444 maxillary second molars), which served as control animals in periodontitis experiments conducted by the Department of Periodontology and the Department of Anatomy at the College of Dentistry, Gangneung-Wonju National University, were initially examined. After excluding fractured or missing teeth, 402 teeth were included in the final analysis. Root fusion was evaluated using micro-computed tomography and categorized by the degree of fusion. To examine the relationship between fused roots and alveolar bone loss, the distance from the cementoenamel junction to the alveolar bone crest was measured on the mesial and distal sides of the maxillary second molars.

Results: Root fusion was found in 10.4% of animals and 6.5% of teeth. Two types of fusion were observed: mesio-palatal (MP) and disto-palatal. Partial root fusion was more frequent than complete fusion. Within the ligation group, teeth with MP fusion exhibited greater alveolar bone loss than those without root fusion (P<0.05).

Conclusions: Within the limitations of this study, maxillary second molars with MP root fusion accelerated alveolar bone loss in ligated teeth in a LIP mouse model. Future research should consider deviations resulting from MP root fusion.

Objective: It is well-established that muscle mass strength is a key factor in healthy physical functioning and is necessary for an active lifestyle. Handgrip strength (HGS) is the most convenient and cost-effective method for evaluating overall muscle strength in the body. Various studies have investigated the direct impact of inflammatory oral diseases on HGS, but with conflicting results. This systematic review investigated previous study data and analysed the causal factors in oral disease that affect HGS.

Methods: The PubMed, Scopus, and Web of Science databases were searched for articles using relevant keywords. Based on the inclusion criteria, 8 cross-sectional studies were selected, and the extracted data was interpreted and analysed systematically. Quality assessment was done using the National Institutes of Health Quality Assessment Tool.

Results: Although 4 studies were shown to have used good quality assessment tools, heterogeneity in the methodology and data analysis prevented us from conducting a meta-analysis. Most of the studies were conducted between 2020 to 2022 and 7 were from Asian countries. The findings of these studies indicated a positive correlation between good oral health and strong HGS. Poor oral habits and oral conditions such as periodontitis and tooth loss inversely affected HGS, as did intrinsic factors like age and sex.

Conclusions: Limited global studies and heterogeneous study data emerged as the major shortcomings in our systematic study review and precluded meta-analysis. Therefore, further studies are needed with standard methodologies and outcome measures as well as good global representation.

Trial registration: PROSPERO Identifier: CRD42023441854.

Purpose: This study aimed to identify new susceptibility modules and genes by analyzing the transcriptional profiles of peri-implantitis and periodontitis within the same host environment, using weighted gene co-expression network analysis (WGCNA).

Methods: Gingival tissue samples were collected from 10 patients, each presenting with both periodontitis and peri-implantitis sites, and were used for RNA sequencing. We conducted WGCNA to identify key modules that showed distinct transcriptional expression profiles between periodontitis and peri-implantitis. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses were carried out using R software. Genes with an adjusted P value greater than 0.05 were excluded from gene selection using the Pearson correlation method.

Results: A total of 2,226 regulated genes were identified, and those with similar expression patterns were grouped into 5 color-coded functional modules using WGCNA. Among these, 3 modules showed distinct differences in expression profiles between peri-implantitis and periodontitis. The turquoise and yellow modules were associated with upregulation in peri-implantitis, while the blue module was linked to periodontitis. This finding suggests that peri-implantitis and periodontitis have significantly different transcriptional signatures. Over-representation analysis was conducted to explore the component genes of the established modules. The top-ranked genes, selected based on their network connectivity within the modules, were identified using DESeq2 and were considered hub genes.

Conclusions: WGCNA revealed distinct modular gene patterns in peri-implantitis and periodontitis, highlighting transcriptional differences between the 2 conditions. Notably, we identified 10 key genes from each of the 3 modules-the blue module associated with periodontitis-dominant pathways, and the turquoise and yellow modules associated with peri-implantitis-dominant pathways. The hub genes and pathways unveiled in this research are likely key contributors to the progression of peri-implantitis and warrant further exploration as promising candidates.

Purpose: Gingival fibroblasts are a major cellular component of the connective tissue and play a crucial role in wound healing and tissue regeneration through collagen synthesis. This study aimed to assess the effect of polynucleotide (PN) combined with cross-linked hyaluronic acid (HA) on the proliferation, differentiation, and anti-inflammatory responses of human gingival fibroblasts-1 (HGF-1).

Methods: In this in vitro experimental study, HGF-1 cells were cultured with PN/HA, PN, HA, and enamel matrix derivative (EMD). Cell proliferation and migration were assessed at 24 hours and 48 hours, respectively. Long-term cultures were evaluated for collagen and proteoglycan deposition using sirius red and alcian blue staining. Levels of phospho-nuclear factor-κB (NF-κB) p65, collagen type I (Col 1), and interleukin-6 (IL-6) were measured using Western blot analysis or enzyme-linked immunosorbent assay.

Results: All experimental groups exhibited increased cellular proliferation and migration compared to the control group. Similar to EMD, PN/HA promoted the synthesis of Col 1 and proteoglycans. At concentrations of 2.5 mg/mL for PN and HA, and 1.0 mg/mL for PN/HA, significant anti-inflammatory effects were observed. These effects included reductions in phospho-NF-κB p65 levels and IL-6 production when exposed to lipopolysaccharides from Porphyromonas gingivalis. EMD, however, did not demonstrate these anti-inflammatory effects.

Conclusions: Within the limitations of this study, we concluded that PN/HA improves gingival tissue healing by promoting cell proliferation and migration, facilitating rapid collagen deposition, and exerting anti-inflammatory effects.

Purpose: Hormonal fluctuations, primarily in progesterone and estrogen during the menstrual cycle, may influence periodontal tissues, with inflammatory cytokines playing a crucial role. Therefore, our primary objective was to assess clinical periodontal parameters and measure levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in gingival crevicular fluid (GCF) throughout the menstrual cycle.

Methods: This longitudinal prospective study was conducted from February to April 2022 and included 50 participants. We assessed clinical periodontal parameters-plaque index (PI), gingival index (GI), pocket depth (PD), clinical attachment loss (CAL), and tooth mobility-at three stages of the menstrual cycle: menstruation day, ovulation day, and premenstrual day. Additionally, GCF samples were collected using paper points. These samples were then stored and analyzed for levels of IL-1β, IL-6, and TNF-α using enzyme-linked immunosorbent assays.

Results: There were 25 participants in our study. The GI, PD, and CAL increased significantly during the menstrual cycle and were significantly higher during the premenstrual phase than in the ovulation phase (P<0.05). The levels of GCF IL-1β (P=0.012), IL-6 (P=0.002), and TNF-α (P=0.015) showed statistically significant throughout the menstrual cycle compared to baseline which was the menstrual (follicular) phase. Furthermore, the GCF levels of IL-1β and IL-6 reached their peak during the luteal or premenstrual phase, whereas TNF-α peaked during the ovulation phase. The increase in biological markers was more pronounced between the menstruation phases than the clinical periodontal markers.

Conclusions: All clinical periodontal parameters, except for the PI, showed a slight increase from the follicular phase to the luteal phase, with significant differences observed between each phase. The levels of GCF IL-1β (P=0.012), IL-6 (P=0.002), and TNF-α (P=0.015) were statistically significant, with increases in IL-1β and IL-6 throughout the menstrual cycle, peaking in the luteal phase. This demonstrates the influence of the menstrual cycle on clinical periodontal and GCF inflammatory markers.

Purpose: This study aimed to analyze the bone regeneration and biosorption patterns of different bone substitutes in a rabbit skull defect model.

Methods: Four circular 8 mm-defects were created in the cranium of 12 New Zealand white rabbits, each weighing approximately 3 kg. Each defect was randomly assigned to one of 4 treatment groups: cortical deproteinized porcine bone mineral (DPBM), cancellous DPBM, biphasic calcium phosphate (BCP) with a 6:4 ratio of hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) (TCP4), and BCP with a 2:8 ratio of HA to β-TCP (TCP8). The rabbits were euthanized at either 6 weeks (n=6) or 12 weeks (n=6) post-surgery. The harvested specimens were then analyzed both radiographically and histomorphometrically.

Results: In the micro-computed tomography analysis, no statistically significant differences were observed among the 4 groups, except in the bone graft volume/tissue volume (GV/TV) at 12 weeks. Cortical DBPM exhibited a higher GV/TV ratio than cancellous DBPM at the same time point. The histomorphometric analysis revealed increased biosorption in cancellous DBPM compared to cortical DBPM at 12 weeks. However, the percentage of newly formed bone did not significantly differ among the 4 groups.

Conclusions: All types of bone substitutes demonstrated similar patterns of bone regeneration at both 6 and 12 weeks of observation. However, cancellous DPBM exhibited a higher rate of bioabsorption compared to other bone substitutes, suggesting that it may have different indications or applications in guided bone regeneration protocols.

Purpose: A small magnetic peg, named "BracketPeg," has been developed as an attachment magnet for implant prostheses. This study aimed to determine the feasibility of measuring implant stability at the prosthesis level, evaluate the reliability and accuracy of BracketPeg, and examine the consistency of measurements obtained using other devices for damping capacity assessment (DCA) and resonance frequency analysis (RFA).

Methods: Forty implants were installed into artificial bone blocks, with each block representing 1 of 4 different diameters (3.5, 4.0, 4.5, and 5.5 mm; 10 implants per diameter). Each implant was paired with a customized zirconia prosthesis that matched the implant diameter. Implant stability was measured at both the fixture and prosthesis levels using Anycheck™ (Neobiotech) for DCA and Osstell™ Beacon (W&H) and ChecQ™ (Dentis) for RFA. To obtain prosthesis-level measurements using RFA devices, BracketPeg was attached to the coronal, middle, and apical thirds of the prosthesis to evaluate implant stability.

Results: The implant stability quotient (ISQ) was significantly lower at the prosthesis level than at the fixture level (P<0.001), reflecting the impact of the increased mass and size of the prosthesis. RFA values varied depending on the position of BracketPeg, with lower stability values observed at the coronal position than at the apical position. The 2 RFA devices demonstrated reasonable agreement between ISQ measurements, with a mean difference of -0.58 (95% confidence interval: ±0.31).

Conclusions: BracketPeg provides reliable and consistent implant stability measurements at the prosthesis level compared to other devices, making it a practical and feasible tool for the clinical evaluation of implants.