Journal of Periodontal and Implant Science最新文献

Purpose: Immediate implant placement (IIP) offers several advantages, including minimizing hard and soft tissue deformation, reducing implant time and cost, and rapidly restoring tooth function. However, IIP is technically challenging due to the need to secure initial stability and limit functional loading during healing. Therefore, this study aimed to evaluate the clinical outcomes of a bone-level implant featuring a dual thread design-an upper U-shaped thread and a lower V-shaped thread-with an 11° internal hexagonal connection in IIP within the maxillary esthetic zone.

Methods: This study included 20 patients. Implants were inserted immediately after tooth extraction. Soft tissue changes were evaluated before tooth extraction (V0), after IIP (V1), at prosthesis delivery (V5), at a 3-month follow-up after prosthesis delivery (V6), and at a 1-year follow-up (V8). Bone dimensional changes were assessed at V1 and V8 using cone beam computed tomography, and the marginal bone level (MBL) was evaluated at V6 and V8 using 2-dimensional.

Results: Of the 20 patients, 3 dropped out due to osseointegration failure during the follow-up period. Although the horizontal dimensions of the soft and hard tissues decreased slightly, the gingival margin and MBL remained well maintained throughout the follow-up.

Conclusions: Within this limited dataset, the lower V-shaped thread enabled favorable initial stability in IIP, and the esthetic outcomes were positive-with minimal gingival recession and marginal bone loss. Long-term follow-up is required to fully assess the impact of thread design and connection on esthetics.

Trial registration: Clinical Research Information Service Identifier: KCT0008231.

The morphogenesis of peri-implant soft tissues following surgical trauma, along with the nature, topography, and design of implant-prosthetic material surfaces, leads to peri-implant tissues that exhibit unique histological and morphological characteristics. It has been shown that mucosal phenotypes with a mucosal thickness of at least 2 mm and a keratinised mucosa width of at least 2 mm promote proper integration and a biological seal at the mucosa-implant interface. This seal prevents pathogen penetration, protects the underlying peri-implant bone, and reduces susceptibility to inflammatory peri-implant diseases (IPDs). Furthermore, even under ideal conditions, peri-implant soft tissues demonstrate less mechanical resistance, stability, and hermeticity compared to periodontal tissues. These deficiencies are directly associated with both the onset and progression of IPDs such as peri-implant mucositis (PM) and peri-implantitis (PI). Over recent decades, the prevalence of PM and PI has risen, making them the primary causes of implant failure. Given that the characteristics of peri-implant mucosa are closely linked to the progression of these diseases, a deep understanding of the biology of peri-implant soft tissues is crucial for developing strategies to either avoid or minimise the impact of IPDs on implant therapy outcomes. This comprehensive review of the literature aims to provide a precise and detailed description of the structure, biology, and function of peri-implant soft tissues, starting from their formation process and linking their morphogenic characteristics to the establishment and evolution of IPDs. Additionally, the composition of the microbiome and the most relevant anti/pro-inflammatory mediators involved in the development of IPDs are summarised.

Purpose: This retrospective study aimed to evaluate the long-term survival rate and marginal bone loss (MBL) of tapered-straight-tapered dental implants, considering various associated factors, over an observational period of ≥5 years.

Methods: This study included 186 patients who underwent tapered-straight-tapered dental implant placement at Seoul National University Dental Hospital from 2014 to 2019. Digital panoramic radiographic images and dental records were examined. We evaluated multiple variables, such as sex, age, diabetes mellitus (DM), smoking status, placement region, jaw type (maxilla and mandible), implant diameter, implant length, staged surgery, immediate placement, splinted prosthesis, and implant placement depth (IPD). We first determined the implant survival rate using Kaplan-Meier analysis and analyzed potential risk factors for implant survival using mixed-effects Cox proportional hazards regression. Next, the Mann-Whitney and Kruskal-Wallis tests were used to examine differences in MBL across variables. Linear mixed-effects models with backward stepwise selection were used to identify associations between risk factors and MBL.

Results: This study included 316 implants in 186 patients, monitored over a follow-up period of 7.0±1.36 years. The cumulative survival rate of the implants was 98.1%. The average mesial and distal MBLs were 0.59±1.36 mm and 0.68±1.36 mm, respectively. Linear mixed-effects models indicated that MBL exhibited statistically significant positive correlations with DM (Coeff.=0.614, P=0.026) and staged surgery (Coeff.=0.410, P=0.002). Additionally, greater mesial IPD was associated with reduced MBL (Coeff.=-0.143, P=0.046), and a similar trend was observed for distal IPD (Coeff.=-0.316, P=0.068).

Conclusions: This study demonstrated a high cumulative survival rate for tapered-straight-tapered dental implants over a 5-year period. DM, staged surgery, and IPD showed strong associations with increased MBL. The results suggest that tapered-straight-tapered implants offer advantages in terms of peri-implant MBL and consistent clinical outcomes. These findings underscore the importance of considering these variables in clinical decision-making to optimize implant outcomes.

Purpose: Odontogenic ameloblast-associated protein (ODAM) is a small secretory protein produced by the junctional epithelium (JE) and mature ameloblasts. It plays a role in odontogenesis and mediates the adhesion of JE to enamel. We used human gingival epithelial cells to evaluate the mechanism of ODAM gene expression regulation in the JE by interleukin (IL)-6.

Methods: Ca9-22, Sa3, and HSY cells were stimulated with IL-6 (10 ng/mL), after which total RNA and proteins were extracted. Real-time polymerase chain reaction and Western blot analyses were performed to assess the expression levels of ODAM mRNA and protein. Luciferase (LUC) assays were employed using LUC constructs with varying lengths of the ODAM gene promoter sequence. Gel mobility shift and chromatin immunoprecipitation (ChIP) analyses were conducted to investigate the binding of transcription factors to response elements within the gene promoter.

Results: Treatment with IL-6 increased the expressions of ODAM mRNA and protein. Additionally, it induced promoter activity of the ODAM gene, while LUC activity was suppressed by inhibitors of protein kinase A, tyrosine kinase, MEK1/2, phosphatidylinositol 3-kinase, nuclear factor-κB, signal transducer and activator of transcription (STAT) 3, and glycoprotein 130. Gel mobility shift and ChIP analyses revealed that IL-6 induced the binding of yin yang 1 (YY1), CCAAT/enhancer-binding protein (C/EBP) β, GATA binding protein (GATA), and phospho-STAT3 to the YY1, C/EBP, GATA, and interferon-γ activated transcriptional element (GATE) 1-3 elements.

Conclusions: These findings indicate that IL-6 upregulates ODAM gene expression by targeting the YY1, C/EBP, GATA, and GATE1-3 elements in the promoter region of the human ODAM gene.

Purpose: Chronic low-grade inflammation is linked to the biology of aging; however, evidence supporting a causal relationship between periodontitis-a dysbiotic biofilm-initiated inflammatory disease-and accelerated aging remains limited. This study investigated the causality between periodontitis and biological aging and identified potentially shared genomic loci, genes, and pathways.

Methods: We conducted a 2-sample Mendelian randomization (MR) analysis to explore the causality of periodontitis on age acceleration measures (DNAm PhenoAge acceleration, GrimAge acceleration, Hannum age acceleration, and intrinsic epigenetic age acceleration) using a dataset from genome-wide association studies of European ancestry populations. Independent genetic variants associated with each trait were used as instrumental variables. The inverse variance-weighted (IVW) method served as the primary MR approach, supplemented by sensitivity testing. We also performed additional statistical genetic analyses to identify pleiotropic loci, shared functional genes, and potential biological pathways, integrating large-scale expression quantitative trait loci data from blood samples.

Results: The MR analysis indicated a causal relationship between periodontitis and DNAm PhenoAge acceleration (IVW β=0.308; 95% confidence interval, 0.056-0.561; P=0.017), a finding corroborated by sensitivity analyses. There was a significant genetic overlap between periodontitis and age acceleration. Pleiotropic analysis revealed 24 shared SNPs associated with 242 genes, predominantly involved in immune functions and pathways related to cellular processes. Further integration analysis showed that 91 of these pleiotropic genes were causally linked to both conditions, with C6orf183 identified as a potential mediator.

Conclusions: This study presents compelling genetic evidence supporting a causal relationship between periodontitis and accelerated aging. Further research is required to validate these findings and investigate the underlying mechanisms.

Purpose: The aim of this study was to conduct a bibliometric analysis of the periodontal plastic surgery literature to identify trends, research gaps, and key themes within the field and to establish a perspective on documented research.

Methods: This bibliometric study examined research outputs on mucogingival surgery indexed in the Web of Science database from 1990 to 2023. The Science Mapping Analysis Tool (SciMAT) software was used to visualize and predict research trends on this topic.

Results: An analysis of publication distribution by year revealed a decline in the number of publications between 1984 and 1995, followed by an overall upward trend after 1996 despite occasional decreases. The United States contributed the most with 593 publications, and Wang HL (n=74) was the most prolific author. The most frequently used keyword was "gingival recession" (n=625). Overall, the publications received 44,859 citations, averaging 25.49 citations per publication.

Conclusions: Researchers have made significant efforts to improve clinical practices and procedures in periodontal plastic surgery, resulting in an increase in studies over recent years. By analyzing thematic maps and clusters-using indicators such as frequency, citations, and centrality-researchers can identify the strengths, weaknesses, and gaps in current research.

Purpose: To determine the early healing outcomes of re-entry sinus floor elevation (SFE) after previous complete sinus membrane perforation.

Methods: In six rabbits, the sinus membrane of one maxillary sinus was intentionally perforated (≥10 mm), and a collagen matrix was applied. SFE was performed on both sinuses after 8 weeks, establishing 2 groups: SFE after previous complete sinus membrane perforation (group SFE_ComPerf) and SFE with an intact sinus membrane (group SFE). The animals were euthanized 4 weeks after SFE. Micro-computed tomographic (micro-CT), histological, and histomorphometric analyses were performed.

Results: On micro-CT, no statistically significant differences were observed in total augmented volume or mineralized tissue volume. Histologically, impaired new bone formation was observed near the sinus membrane in the SFE_ComPerf group. Histomorphometric analysis revealed that the area of newly formed bone was significantly smaller in group SFE_ComPerf than in group SFE (5.8±2.7 mm² vs. 10.5±1.9 mm², P<0.05). Such reduced bone formation in the SFE_ComPerf group was also evident in one region of interest (P<0.05).

Conclusions: Complete sinus membrane perforation (>10 mm) may compromise new bone formation in re-entry SFE.

This systematic review compares xenogeneic collagen matrices (XCMs) and autogenous graft-based techniques, focusing on 1) the effectiveness of XCMs (non-crosslinked XCM [XCM*] and crosslinked XCM [VCMX]) vs. connective tissue graft (CTG) for increasing buccal mucosal thickness (MT), and 2) the effectiveness of XCM* vs. free gingival graft (FGG) in augmenting buccal keratinised mucosa width (KMW) at implant sites. MEDLINE (PubMed), Web of Science, and Scopus were searched from inception to August 2024. Randomised controlled trials (RCTs) involving systemically healthy patients with peri-implant mucosal deficiencies (MT <2 mm and/or KMW <2 mm) were included. Studies were required to have 2 parallel control groups comparing XCMs with CTG and/or XCM* with FGG, and a minimum follow-up of 3 months. Data were extracted and analysed using a random-effects model, with risk of bias evaluated via the Cochrane risk of bias tool 2. Seventeen RCTs met inclusion criteria for qualitative synthesis (XCMs vs. CTG, n=12; XCMs vs. FGG, n=5), with 14 RCTs included in the meta-analysis (XCMs vs. CTG, n=9; XCMs vs. FGG, n=5). Subgroup analysis of XCM* or VCMX vs. CTG showed a significantly greater MT increase with CTG than with XCM* (pooled mean difference [MD], 0.27; 95% confidence interval [CI], 0.05 to 0.49; P=0.01). No significant difference in MT was observed between VCMX and CTG (pooled MD, 0.02; 95% CI, -0.17 to 0.22; P=0.83). For KMW, FGG provided a significantly greater increase than XCM* (pooled MD, 1.47; 95% CI, 0.63 to 2.30; P=0.0006). RCTs on XCMs vs. CTG showed moderate risk of bias, while those on XCM* vs. FGG showed low risk. XCM* is less effective than CTG for increasing MT at buccal implant sites, and less effective than FGG for increasing buccal KMW. No statistical difference was found between VCMX and CTG for MT augmentation.

Purpose: This study aimed to establish a proof of concept for the guided bone regeneration (GBR) procedure using molded collagenated equine bone mineral (CEBM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in a canine peri-implantitis model, and to identify the key factors essential for effective bone regeneration in peri-implant defects.

Methods: Twelve dental implants were placed in the mandibles of 4 adult male beagle dogs. Each implant was randomly assigned to 1 of 3 groups: GBR with molded CEBM soaked in rhBMP-2 solution (CEBM/BMP2 group, n=4); GBR with molded CEBM alone (CEBM group, n=4); or open flap debridement (OFD group, n=4). Peri-implantitis was induced using cotton retraction cords following osseointegration. After ligature removal, all groups underwent OFD with implant surface decontamination, and GBR was subsequently performed according to group allocation. No further treatment was provided in the OFD group. Clinical and radiographic evaluations were conducted at 4-week intervals, and at 16 weeks, histological, fluorescent labeling, and micro-computed tomographic (micro-CT) analyses were performed.

Results: The CEBM/BMP2 group demonstrated a significantly higher bone volume fraction in micro-CT analysis, alongside superior histomorphometric outcomes, including greater first bone-to-implant contact height, crestal height, and new bone area. The mean re-osseointegration ratio was notably higher in the CEBM/BMP2 group (buccal: 74%, lingual: 94%) compared to both the CEBM (buccal: 20%, lingual: 35%) and OFD groups (buccal: 12%, lingual: 45%).

Conclusions: The GBR procedure using molded CEBM with rhBMP-2 substantially enhanced new bone formation and implant re-osseointegration in peri-implantitis-associated defects, compared to molded CEBM alone or OFD without GBR.

Purpose: This study was conducted to evaluate the 3-year predictability and validity of the modified tunnel technique, both with and without the use of enamel matrix derivative (EMD), for treating deep and narrow gingival recession defects (GRDs) in the mandibular anterior region.

Methods: Overall, 31 GRDs were treated using the modified tunnel technique combined with subepithelial connective tissue graft. The cohort was divided into 2 groups: one with the adjunctive use of EMD (n=16) and the other without EMD (n=15). Clinical outcomes, including recession depth (RD), keratinized tissue width (KTW), mean root coverage (MRC), and complete root coverage (CRC), were evaluated at baseline, as well as at 6 months, 1 year, and 3 years postoperatively. Patient discomfort was assessed with a self-report questionnaire 2 weeks after surgery.

Results: At the 3-year follow-up, no statistically significant differences were observed between the 2 treatment modalities in clinical parameters, including RD (EMD, -6.47±2.23 mm; non-EMD, -5.10±3.23 mm), KTW (EMD, 1.03±0.96 mm; non-EMD, 1.00±1.02 mm), MRC (EMD, 86.62%±21.18%; non-EMD, 80.24%±38.73%), and CRC (EMD, 62.5%; non-EMD, 73.3%). Furthermore, no significant differences were found between the groups in terms of early and subjective postoperative discomfort, including pain and swelling.

Conclusions: Within the limitations of this study, the modified tunnel technique, whether used alone or in conjunction with EMD, demonstrated benefits in the treatment and maintenance of deep and narrow GRDs.