Journal of Periodontal and Implant Science最新文献

Purpose: The Korean Oral Biobank Network (KOBN) collects, stores, and provides oral samples for research. Quality control (QC) of biospecimens is necessary to ensure that they meet the basic prerequisites before being sent to researchers. This study presents the standard operating procedures (SOPs) for the QC of biospecimens.

Methods: QC methods using molecular genetic techniques according to sample types, including teeth, blood, oral soft tissue, oral tissue-derived cells, saliva, mouth rinse solution, dental plaque, and gingival crevicular fluid, are described in detail.

Results: The KOBN established SOP for oral biospecimen QC and assessment methods.

Conclusions: To ensure a stable supply of high-quality biospecimens for researchers, regular QC checks should be carried out according to the SOP following the specifications of the Korea Biobank Network under the Korea Disease Control and Prevention Agency.

Purpose: Periodontitis is an inflammatory disease that results in the loss of periodontal tissue. The endocannabinoid system has anti-inflammatory properties and displays considerable potential for tissue regeneration. In this study, we aimed to explore whether the activation of this system can alleviate or reverse the inflammatory phenotype of human periodontal ligament stem cells (hPDLSCs) induced by exposure to the inflammagen lipopolysaccharide (LPS).

Methods: We investigated the effects of activating specific cannabinoid receptors (CB1 and CB2) on the inflammatory phenotype of LPS-stimulated hPDLSCs. The exogenous ligands WIN55,212-2 and JWH-133 were employed to target the cannabinoid receptors. We conducted a thorough assessment of cell proliferation, metabolic activity, and adipogenic, osteogenic, and chondrogenic differentiation potential. Additionally, we measured cytokine release using enzyme-linked immunosorbent assays.

Results: Exposure to Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) caused an increase in cell proliferation while decreasing metabolic activity. While this exposure did not influence adipogenic or chondrogenic differentiation, it did result in reduced osteogenesis. Additionally, LPS induced the release of interleukin (IL)-6, IL-8, and monocyte chemoattractant protein 1. Immunolabeling revealed the presence of CB1 and CB2 on the cellular membrane, with these receptors playing distinct roles in hPDLSCs. The CB1 agonist WIN55,212-2 was found to increase metabolic activity and promote adipogenic differentiation, whereas the CB2 agonist JWH-133 promoted cell proliferation and osteogenic differentiation. When hPDLSCs were co-exposed to Pg-LPS and CB ligands, JWH-133 slightly ameliorated the inhibition of osteogenic differentiation and suppressed the release of inflammatory cytokines.

Conclusions: This study clarifies the effects of specific CB receptor activation on hPDLCs and the inflammatory phenotype. Stimulation of the endocannabinoid system through the manipulation of endogenous or the application of exogenous cannabinoids in vivo may represent a potent therapeutic option for combating periodontal inflammatory disorders.

Purpose: The nasopalatine canal (NPC) is one of the most significant anatomical markers in the anterior maxillary region. Its location is quite important, especially for implant placement. Therefore, the purpose of this study was to use cone-beam computed tomography (CBCT) to evaluate the morphology, size, and anatomic variations of the NPC.

Methods: A total of 150 individual CBCT images were assessed in various sections to evaluate the dimensions, morphology, and extent of the NPC. Reformatted sagittal images were chosen to classify the shape and course of the canal. The Student's t-test, the χ² test, and Pearson correlation coefficients were used.

Results: The NPC was longer in males than in females, and the mediolateral diameter of the canal was greater in older adults. In sagittal sections, the canal predominantly exhibits a cylindrical shape, while a spindle shape is the least common. In coronal sections, a single shape is most frequently observed, with a Y-shape being the least common. Regarding the orientation of the canal, slanted canals are more prevalent, whereas vertically curved canals are rare. Typically, 2 canal openings are observed, with 4 openings being the least common.

Conclusion: The current study highlights the challenges associated with identifying the anatomical appearance and variations of the NPC. Consequently, possessing a thorough understanding of this anatomy is essential before undertaking any surgical procedures, such as implant placement. This knowledge helps prevent complications such as nerve injury-related loss of sensation, bleeding due to blood vessel injury, and the development of a nasopalatine duct cyst following trauma to the canal during surgery.

Purpose: This research aimed to investigate potential factors associated with the risk of perforation of the labial bone plate, nasal floor, or maxillary sinus floor during immediate implant placement (IIP) in the maxillary premolar area, utilizing a cone-beam computed tomography (CBCT) virtual study.

Methods: CBCT exams from 179 eligible participants, encompassing 716 teeth, were included. Implants were virtually positioned in 2 orientations: along the long axis of the tooth (the prosthetically-driven position) and in an optimal position relative to adjacent anatomical structures (the bone-driven position). Binary logistic regression analysis was employed to assess potential associations between perforation or invasion and various covariates, including sex, age, tooth region, the distance from the tooth apex to the nasal floor or maxillary sinus floor, the angle between the prosthetically- and bone-driven positions (implant-line A angle [ILAA]), and the labial concavity angle (LCA).

Results: The mean ILAA was 18.3°±8.0°, and the angle was significantly larger for the second premolar compared to the first premolar. The mean minimum implant length was 13.0±2.1 mm, with a bone anchorage of 4 mm. The incidence of perforation was 84.1% for the prosthetically-driven position and 40.5% for the bone-driven position. Factors associated with a higher risk of cortical bone wall perforation or invasion of the 2-mm safety margin from surrounding anatomical structures (in the bone-driven position) included female sex, older age, shorter distance from the tooth apex to the nasal cavity/maxillary sinus, and smaller LCA.

Conclusions: A high prevalence of cortical bone wall perforation or invasion of the 2-mm safety margin is anticipated when performing IIP in the maxillary premolar region.

Purpose: This study investigated the effect of implant vertical positioning within alveolar ridge preservation (ARP) sites on implant stability quotient (ISQ) values, which were measured 10 weeks post-implantation.

Methods: Patients who underwent ARP using collagenized deproteinized bovine bone mineral, followed by implant placement in the posterior area, were divided into 2 groups: the within-ARP group and the beyond-ARP group. In the within-ARP group, osteotomy and implant placement occurred within the ARP boundary. In contrast, in the beyond-ARP group, these procedures were performed beyond the ARP boundary, incorporating 3 mm of pristine bone at the implant's apex. Bone quality was assessed by tactile sense, and both insertion torque during implant surgery and ISQ values at 10 weeks post-implant surgery were measured. Multiple linear regression analysis and Pearson correlation analysis were used to explore the relationship between insertion torque and ISQ values.

Results: In total, 30 ARP sites in 28 patients were analyzed. There was no significant difference in bone quality, as determined by tactile sense, between the within-ARP and beyond-ARP groups. At the time of implant placement, the beyond-ARP group exhibited a higher insertion torque (33.33±13.39 Ncm) compared to the within-ARP group (17.08±11.17 Ncm). However, the ISQ values were similar between the 2 groups 10 weeks after implant placement. A positive correlation between insertion torque and ISQ values was confirmed at 10 weeks post-implant.

Conclusions: The engagement of pristine bone may facilitate high insertion torque during the placement of implants in ARP sites. Nevertheless, by 10 weeks post-implantation, the ISQ values were found to be comparable, irrespective of the implant's position.

Purpose: The purpose of this study was to compare the bone healing potential of 1-, 2-, and 3-wall defects following alveolar ridge preservation (ARP) treatment, as well as to evaluate the efficacy of ARP as a treatment option for destructive sites.

Methods: Three groups, characterized by 1-, 2-, and 3-wall defects, were randomly assigned to the maxillary second, third, and fourth premolars in each of 8 beagle dogs. Each defect was created at either the mesial or distal root site of the tooth, which was hemi-sectioned and extracted. The contralateral root was preserved to superimpose with the experimental site for histomorphometric analysis. For each site, either spontaneous healing (SH; control) or ARP (test intervention) was randomly applied. Each group was divided in half and underwent a healing period of either 4 or 12 weeks. The Mann-Whitney U test and Kruskal-Wallis test were used for histomorphometric analyses. Statistical significance was set at P<0.05.

Results: Qualitative analysis revealed a higher percentage of new bone in the apical area compared to the coronal area, regardless of defect type and healing period. In quantitative analysis, the 3-wall defect exhibited a significantly higher percentage of mineralization in the ARP group after 12 weeks of healing (ARP: 61.73%±7.52%; SH: 48.84%±3.06%; P=0.029). An increased percentage of mineralization was observed with a greater number of remaining bony walls, although this finding did not reach statistical significance.

Conclusions: Within the limitations of this study, ARP treatment for compromised sockets appears to yield a higher percentage of mineralization compared to SH. Although the effectiveness of the remaining bony walls was limited, their presence appeared to improve the percentage of mineralization in ARP treatment.

The oral cavity provides an ideal environment for microorganisms, including bacteria, viruses, and fungi, to flourish. Increasing attention has been focused on the connection between the oral microbiome and both oral and systemic diseases, spurring active research into the collection and analysis of specimens for healthcare purposes. Among the various methods for analyzing the oral microbiome, saliva analysis is especially prominent. Saliva samples, which can be collected non-invasively, provide information on the systemic health and oral microbiome composition of an individual. This review was performed to evaluate the current state of the relevant research through an examination of the literature and to suggest an appropriate assay method for investigating the oral microbiome. We analyzed articles published in English in SCI(E) journals after January 1, 2000, ultimately selecting 53 articles for review. Articles were identified through keyword searches in the PubMed, Embase, Cochrane, Web of Science, and CINAHL databases. Three experienced researchers conducted full-text assessments following title and abstract screening to select appropriate papers. Subsequently, they organized and analyzed the desired data. Our review revealed that most studies utilized unstimulated saliva samples for oral microbiome analysis. Of the 53 studies examined, 29 identified relationships between the oral microbiome and various diseases, such as oral disease, Behçet disease, cancer, and oral lichen planus. However, the studies employed diverse methods of collection and analysis, which compromised the reliability and accuracy of the findings. To address the limitations caused by methodological inconsistencies, a standardized saliva assay should be established.

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: 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.