PURPOSE:This systematic review and meta-analysis quantitatively synthesized the available evidence on the association between periodontal disease (PD) and the risk of medication-related osteonecrosis of the jaw (MRONJ). We also examined whether MRONJ risk varied according to PD severity among patients receiving antiresorptive or antiangiogenic therapy. METHODS:MEDLINE, Web of Science, Embase, Scopus, and Google Scholar were comprehensively searched for studies published through November 30, 2025, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eligible studies were required to provide a reproducible definition of PD based on clinical, radiographic, guideline-based, or predefined administrative-code criteria. Studies relying on non-operationalized clinical labels without sufficient diagnostic detail were excluded. A random-effects meta-analysis was performed using log-transformed relative-effect estimates and their standard errors. To address heterogeneity in exposure definitions, studies were stratified into a severe/procedure-linked group and a moderate-to-mixed group. RESULTS:Eight observational studies met the eligibility criteria and were included in the quantitative synthesis. The primary meta-analysis showed a statistically significant association between PD and MRONJ, indicating that patients with PD had an approximately threefold higher risk of developing MRONJ than those without PD (pooled relative-effect estimate, 3.02; 95% confidence interval [CI], 1.99-4.56). In subgroup analyses, the severe/procedure-linked group had a higher pooled relative-effect estimate (4.26; 95% CI, 1.96-9.24) than the moderate-to-mixed group (2.39; 95% CI, 1.45-3.94). However, the between-subgroup difference was not statistically significant; therefore, the subgroup findings should be interpreted as exploratory. CONCLUSIONS:Current evidence supports an association between PD and increased MRONJ risk in patients receiving antiresorptive or antiangiogenic therapy. Although the subgroup findings suggest that more advanced periodontal breakdown may be associated with greater risk, this severity-based pattern should be interpreted cautiously and confirmed in future studies with larger sample sizes and standardized diagnostic criteria.
PURPOSE:This pilot study investigated the effects of different extraction-socket bone-resorption patterns on alveolar ridge preservation (ARP) performed with an open-wound healing technique. METHODS:Sites were divided into two groups according to cone-beam computed tomography (CBCT) findings obtained immediately after ARP surgery (T1): group 1 included sockets with vertical bone resorption >1/3 of the buccal/labial or lingual/palatal bone wall, and group 2 included sockets with vertical bone resorption ≤1/3 of the buccal/labial and lingual/palatal bone walls. Follow-up CBCT was performed approximately 5 months after surgery (T3). Hard-tissue changes were measured by superimposing CBCT images obtained at T0 (before tooth extraction), T1, and T3. Soft-tissue healing was evaluated at suture removal (T2), and biopsy specimens were collected before implant placement. RESULTS:Sixteen participants with 19 sites completed this pilot study. All included patients underwent ARP with an intentionally exposed xenogeneic collagen matrix seal; however, one patient did not undergo implant-placement surgery at our hospital. Overall, CBCT measurements of ridge alterations showed excellent intra-rater reliability and minimal systematic bias. Bone resorption occurred in both groups (P<0.05), reflecting the natural bone-remodeling process. However, no intergroup differences were observed in horizontal or vertical dimensional changes. In addition, locally estimated scatterplot smoothing analysis identified bootstrap median inflection points below the 1/3 threshold, suggesting a possible nonlinear relationship between the vertical resorption proportion and three-dimensional changes. No statistically significant differences were observed in soft-tissue healing or implant-related outcomes. Histomorphometric evaluation of biopsy specimens showed new bone formation without signs of inflammation or fibrous encapsulation. CONCLUSIONS:Within the limitations of this study, intentionally exposing the xenogeneic collagen matrix seal yielded comparable outcomes in non-contained and contained sockets. This finding may reflect the material's ability to reduce the adverse effects of socket-wall resorption; however, larger multicenter studies are warranted. TRIAL REGISTRATION:Chinese Clinical Trial Registry Identifier: ChiCTR2300078331.
PURPOSE:This study aimed to compare the clinical and radiographic efficacy of nonsurgical treatment with enamel matrix derivative (EMD), EMD-assisted surgical treatment, and nonsurgical treatment alone for intrabony defects. METHODS:Sixty patients with intrabony defects were randomly assigned to one of the following groups: (i) nonsurgical subgingival debridement alone (negative control [NC]), (ii) minimally invasive surgical technique (MIST) with EMD application (positive control [PC]), or (iii) nonsurgical subgingival debridement with EMD application (test group). Clinical and radiographic measurements, along with optical impressions, were obtained at baseline and during the 6-month follow-up period. RESULTS:All 60 patients completed the trial, with 20 participants in each group. The proportion of patients achieving the composite outcome (final probing pocket depth ≤4 mm and reduction in clinical attachment loss ≥3 mm) did not differ significantly among the groups (NC: 9/20; PC: 8/20; test: 11/20; P = 0.626). However, bleeding on probing was significantly lower in the test group than in the PC group at both 3 and 6 months (P=0.029 for both timepoints). Gingival recession assessed using optical impressions demonstrated mean changes from baseline of 0.24±0.27 mm, 0.51±0.56 mm, and 0.20±0.18 mm at 6 months in the NC, PC, and test groups, respectively, with significant intergroup differences over time (P=0.038). The amount of radiographic bone gain did not differ significantly among the groups (P>0.05). CONCLUSIONS:The nonsurgical application of EMD resulted in clinical and radiographic improvements comparable to those achieved with EMD-assisted MIST procedures. TRIAL REGISTRATION:Clinical Research Information Service Identifier: KCT0007436.
PURPOSE:This study evaluated the regenerative potential of a novel polyethylene glycol (PEG)-chitosan hydrogel as an alternative to a conventional collagen membrane for guided tissue regeneration (GTR) of class II furcation defects in a canine model. METHODS:Standardized class II furcation defects were created in the maxillary third and fourth premolars of 6 beagle dogs. Sites were randomly allocated to 4 groups: 1) sham control, 2) particulate biphasic calcium phosphate (BCP) with a cross-linked collagen membrane (O3CM), 3) collagenated BCP with a collagen membrane (O3ColCM), and 4) particulate BCP with PEG-chitosan hydrogel (O3TG). After 8 weeks, specimens were processed for histological and histomorphometric analyses. The primary outcome was hard tissue area (HTA) within a predefined 3-mm region of interest. RESULTS:Histologically, O3TG showed consolidated graft particles in close contact with the surrounding tissues and new bone formation extending coronally from the defect base, with no notable inflammatory response. Histomorphometric analysis revealed no statistically significant differences among the groups. Median HTA values ranged from 1.55 mm² in O3TG to 1.92 mm² in the control group (P=0.997). The non-filled area tended to be smaller in O3CM (0.68 mm²) and O3TG (0.66 mm²) than in the control group (1.14 mm²) and O3ColCM (1.58 mm²), although the difference was not statistically significant (P=0.258). CONCLUSIONS:Within the limitations of this study, PEG-chitosan hydrogel achieved regenerative outcomes comparable to those of collagen membrane-based GTR while stabilizing BCP particles without adverse inflammation. Given its ease of handling and biocompatibility, PEG-chitosan hydrogel may represent a clinician-friendly alternative to collagen membranes for periodontal regeneration in class II furcation defects.
PURPOSE:This study evaluated whether vestibule depth (VD) affects peri-implant inflammation and mucosal margin stability in the posterior mandible independently of keratinized mucosa width (KMW). METHODS:A total of 129 patients, each with a single implant in the mandibular premolar or molar region, were included. Clinical variables, including gingival index, plaque index (PI), peri-implant probing depth, clinical attachment level (CAL), gingival bleeding time index (GBTI), VD, KMW, mucosal thickness (MT), mucosal recession (MR), peri-implant soft tissue phenotype, and peri-implant soft tissue dehiscence (PISTD), were assessed. Multiple linear regression analysis was performed to determine the associations of GBTI, MR, and PISTD type with the independent variables PI, KMW, age, implant diameter, sex, function time, implant location, CAL, MT, VD, and phenotype classification. RESULTS:Implants with adequate KMW (≥2 mm) displayed greater VD and MT, less MR, and a thicker phenotype than implants with inadequate KMW (<2 mm) (P<0.001 for all). PISTD class II defects were observed more frequently in the group with adequate KMW, whereas class III defects were more common among the patients with inadequate KMW (P=0.001). Implants with sufficient VD (≥6 mm) showed greater KMW and MT and less MR than implants with insufficient VD (<6 mm) (P=0.026 for MR; P<0.001 for all other comparisons). Based on the multiple regression analysis, KMW was significantly associated with GBTI, MR, and PISTD types and subtypes (P<0.05 for all), whereas VD was not significantly associated with any of these variables. CONCLUSIONS:VD was not significantly associated with peri-implant inflammation or soft tissue stability, whereas KMW showed a stronger association with these parameters. These findings suggest that KMW, independent of VD, plays an important role in peri-implant soft tissue health in the posterior mandible.
PURPOSE:The vertical dimension of soft tissue is crucial for planning implant placement, tissue augmentation procedures, and maintaining the long-term health of peri-implant tissue. However, evidence regarding the variation in soft tissue thickness at implant sites and the factors influencing it is limited. This study investigated the potential determinants of soft tissue thickness variation at implant sites following tooth extraction due to severe periodontitis. METHODS:In total, 176 hopeless teeth in 94 patients with stage III/IV periodontitis were extracted due to severe periodontal destruction. Pre-extraction parameters were documented based on clinical and radiographic examinations, including tooth position; presence or absence of neighboring teeth; and the height difference between the proximal alveolar crest of the neighboring teeth and the extracted tooth. Socket morphology was examined clinically. During implant placement, vertical soft tissue thickness was categorized as thin (<2 mm), normal (≥2 mm to <5 mm), and thick (≥5 mm). Logistic regression analyses with generalized estimating equations identified potential factors influencing soft tissue thickness. Interactions among variables were evaluated. RESULTS:The mean vertical soft tissue thickness at the implant site was 3.8±1.3 mm. None of the implant sites showed thin soft tissue. Thick soft tissue was predominantly observed in the maxillary anterior region and was significantly associated with discrepancies in socket bone wall height. When pre-extraction periodontal therapy was administered, a notable increase in soft tissue wall height was significantly correlated with the presence of thick soft tissue at the implant site. The absence of neighboring teeth and a healing period of ≥2 months post-extraction did not show significant correlations with soft tissue thickness at the implant sites. CONCLUSIONS:The morphology of the extraction socket, potentially influenced by long-term periodontal inflammation, along with the position of the tooth site, may significantly contribute to variations of soft tissue thickness at the implant site.
PURPOSE:This study compared early soft-tissue healing after open-healing alveolar ridge preservation (ARP) in periodontally compromised extraction sockets according to the type of resorbable sealing material used. METHODS:A total of 127 extraction sockets were categorized into 3 groups according to the sealing material used: (i) absorbable atelocollagen sponge, (ii) resorbable non-cross-linked collagen membrane (CM group), and (iii) acellular dermal matrix. Serial intraoral photographs were obtained at 4 time points: immediately after surgery (T0), at 1.0±0.3 weeks (T1), at 4±1 weeks (T2), and at 15±3 weeks (T3). The primary outcome was open wound percentage, which was used to characterize early soft-tissue healing. Secondary outcomes included the Modified Early Wound Healing Score (m-EHS), time to complete epithelialization, the need for additional bone grafting at implant placement, and marginal bone loss (MBL) after implantation. RESULTS:The CM group showed a distinct early healing pattern characterized by a transient increase in wound exposure at T1. This group also had a significantly higher frequency of additional bone grafting at implant placement (P=0.001). However, MBL after implantation did not differ significantly among the groups. A higher open wound percentage at 1 week postoperatively was positively correlated with greater distal MBL (P=0.006). The m-EHS and final epithelialization time did not differ significantly among the groups. CONCLUSIONS:Early soft-tissue healing after open-healing ARP varied according to the sealing material used. The CM group showed greater early wound exposure and more frequent additional grafting. Greater early wound exposure was also associated with greater distal bone loss. These findings suggest that sealing material characteristics may influence early healing and later clinical outcomes.
PURPOSE:This study evaluated phase-specific peri-implant marginal bone level (MBL) changes associated with abutment disconnection and reconnection during prosthetic procedures by comparing implant-level (IL) and abutment-level (AL) restorative protocols over a 1-year period. METHODS:This two-arm randomized controlled clinical trial included patients receiving posterior mandibular fixed partial dentures following soft tissue augmentation. Implants were randomly assigned (1:1) to IL or AL protocols. In the IL group, repeated abutment disconnection and reconnection were performed during prosthetic procedures, whereas in the AL group, a definitive abutment was connected and maintained without disconnection. Standardized periapical radiographs were obtained at implant placement (T0), 2 weeks after second-stage surgery (T1), at definitive prosthesis delivery (T2), and 1 year after loading (T3). MBL changes were analyzed by phase: suprastructure connection (T1-T0), prosthetic (T2-T1), maintenance (T3-T2), and cumulative (T3-T0). Statistical significance was set at P<0.05. RESULTS:Implant success was 100% at 1 year in both groups. In the IL group, MBL changes were Δ(T1-T0)=-0.41±0.43 mm, Δ(T2-T1)=-0.34±0.38 mm, and Δ(T3-T2)=-0.31±0.43 mm, with a cumulative change of Δ(T3-T0)=-1.06±0.49 mm. In the AL group, the corresponding values were -0.81±0.44 mm, -0.14±0.24 mm, -0.12±0.30 mm, and -1.08±0.39 mm, respectively. Phase-specific remodeling differed between protocols, whereas the cumulative 1-year change was comparable. CONCLUSIONS:Under conditions of vertical soft tissue augmentation, abutment disconnection and reconnection were associated with phase-specific MBL remodeling; however, cumulative 1-year MBL changes were similar between IL and AL protocols.
PURPOSE:Periodontitis is an inflammatory disease of the hard and soft tissues surrounding the teeth and is initiated by bacterial biofilms. Severe alveolar bone resorption often occurs because of marked increases in osteoclast number and activity, which can ultimately lead to tooth loss. Recent evidence suggests that reactive oxygen species (ROS) may act as a common mediator of both osteoclastogenesis and inflammation. METHODS:We examined the effect of the potent antioxidant cobinamide, a vitamin B₁₂ derivative, on osteoclast differentiation from mouse bone marrow macrophage (BMM) precursors in culture and on bone resorption and inflammation in a mouse model of ligature-induced periodontitis. RESULTS:At submicromolar concentrations, cobinamide significantly reduced receptor activator of nuclear factor κB ligand-dependent differentiation of osteoclasts from mouse BMM precursors. In addition, cobinamide rapidly and almost completely abrogated ROS generation and Ca²⁺ oscillations in differentiating osteoclasts, both of which are essential for osteoclastogenesis. Local application of cobinamide in a hydrogel significantly reduced alveolar bone resorption in the ligature-induced periodontitis model, concomitant with a marked reduction in osteoclast number and activity. Furthermore, cobinamide prevented ligature-induced oxidative tissue damage while simultaneously reducing T-cell and macrophage recruitment and the production of interleukin-1β, interleukin-6, and tumor necrosis factor-α. CONCLUSIONS:These results indicate that cobinamide has anti-osteoclastogenic and anti-inflammatory effects in periodontitis, suggesting its potential clinical utility.
PURPOSE:This study aimed to (1) establish the occupying volume ratio (OVR), defined as the proportion of mineralized particulates within grafted sites, using particulate xenografts mixed with either saline or platelet-rich fibrin (PRF), and (2) evaluate how hydration and mechanical manipulation influence OVR in collagenated block-type xenografts. METHODS:Three particulate xenografts and their corresponding collagenated blocks were evaluated. Particulate grafts were mixed with either saline or PRF. Collagenated blocks were assessed under 3 conditions: original, after saline hydration, and after mash-up, defined as mechanical crushing following hydration. All samples were compressed into standardized resin boxes (10×10×10 mm). Micro-computed tomography was used to quantify mineralized volume and calculate OVR. RESULTS:Significant effects of material type (P<0.01) and application condition (P=0.04) were observed for particulate grafts. The OVRs were 48.45±11.89% for saline and 44.24±10.37% for PRF. Among the tested materials, deproteinized porcine bone mineral (DPBM)-OX demonstrated the highest OVR under both conditions and showed significantly greater values than deproteinized bovine bone mineral (DBBM) and DPBM-TG (P<0.05). In collagenated blocks, OVR decreased significantly in a stepwise manner, from 52.40±7.37% in the original state to 41.91±8.75% after hydration and 33.66±6.07% after mash-up. Following mash-up and standardized recompression within the mold, the mean OVRs were reduced to 35.12±5.97% for DBBM, 37.77±1.85% for DPBM-TG, and 28.10±5.12% for DPBM-OX. CONCLUSIONS:Collagenated xenografts undergo a significant reduction in mineral volume density following hydration and mechanical manipulation, which may compromise space maintenance and graft stability. These findings highlight the importance of careful graft handling to preserve volume and optimize regenerative outcomes.
PURPOSE:Periodontitis is a common oral disease characterized by inflammation and destruction of periodontal tissues. Competitive endogenous RNAs (ceRNAs) are known to regulate inflammatory responses. This study aimed to investigate the role of circular RNA MYO9B (circMYO9B), as a potential ceRNA, in the progression of periodontitis and to elucidate its underlying regulatory mechanism. METHODS:This study included 69 healthy controls and 71 patients with periodontitis. Lipopolysaccharide (LPS)-treated periodontal ligament cells (PDLCs) were used as an in vitro model of periodontitis. Reverse transcription-quantitative polymerase chain reaction was performed to quantify circMYO9B, miR-4731-5p, and ubiquitin-specific peptidase 15 (USP15) expression, while enzyme-linked immunosorbent assays were used to measure inflammatory cytokine levels. Cell proliferation, migration, and apoptosis were assessed using the Cell Counting Kit-8 assay, Transwell migration assay, and flow cytometry, respectively. Dual-luciferase reporter assays were conducted to validate the interactions among circMYO9B, miR-4731-5p, and USP15. RESULTS:circMYO9B expression was significantly elevated in the gingival crevicular fluid of patients with periodontitis and in LPS-treated PDLCs. Receiver operating characteristic curve analysis demonstrated that circMYO9B had diagnostic potential for periodontitis (area under the curve: 0.919). LPS stimulation reduced PDLC viability and migratory capacity while increasing inflammatory cytokine production and apoptosis. circMYO9B directly targeted and negatively regulated miR-4731-5p. Silencing circMYO9B significantly attenuated LPS-induced PDLC dysfunction, whereas inhibition of miR-4731-5p abolished the protective effects of circMYO9B knockdown. USP15 was identified as a direct downstream target of miR-4731-5p: overexpression of miR-4731-5p alleviated LPS-induced cellular injury in PDLCs, but this protective effect was markedly reversed by concomitant USP15 overexpression. CONCLUSIONS:circMYO9B is associated with periodontitis progression through the miR-4731-5p/USP15 regulatory axis, suggesting its potential utility as a therapeutic target in periodontitis.
PURPOSE:To retrospectively evaluate the effects of vestibuloplasty using a xenogeneic collagen matrix (XCM) at implant sites with insufficient peri-implant keratinized tissue (PIKT) and a shallow peri-implant vestibule (PIV). METHODS:Patients who underwent vestibuloplasty with an XCM between July 2021 and August 2023 at Kyung Hee University Dental Hospital were included. Inclusion criteria were PIKT <2 mm, PIV <4 mm at baseline, and a follow-up duration of >6 months. Clinical parameters, including PIKT and PIV, were measured at baseline and at 1 month, 6 months, and the final visit. Marginal bone level (MBL), probing depth (PD), bleeding on probing (BOP), and the modified plaque index (mPI) were recorded at the final visit. Descriptive statistical analyses were performed. RESULTS:Thirteen patients with 22 implant sites were included, with a mean follow-up of 1.19±0.27 years. Baseline PIKT and PIV were 0.59±0.57 mm and 2.66±0.81 mm, respectively. At the final visit, the mean gains in PIKT and PIV were 1.52±1.16 mm and 2.73±1.99 mm, resulting in final values of 2.11±1.01 mm and 5.39±1.85 mm, respectively. Clinical and radiographic peri-implant parameters indicated favorable conditions (PD: 2.30±0.61 mm; BOP: 0.15±0.26; mPI: 0.27; MBL: 1.23±0.97 mm). CONCLUSIONS:Vestibuloplasty using an XCM was associated with achieving clinically accepted threshold values for PIKT and PIV while maintaining favorable peri-implant conditions. Long-term follow-up is warranted.
Preclinical animal models are essential for evaluating the biological performance, safety, and translational potential of bone regeneration strategies before human application. Because no single species can fully replicate human skeletal biology, careful selection of an appropriate model is necessary to generate reliable and clinically meaningful evidence. This narrative review summarizes the characteristics, advantages, and limitations of commonly used experimental species, with particular emphasis on their anatomical and biomechanical similarity to humans and their suitability for modeling localized and systemic bone-healing conditions. Rodent models are widely used for early-stage screening because they are cost-effective, genetically manipulable, and well-suited for mechanistic studies. However, their limited cortical thickness, strong intrinsic healing capacity, and lack of true Haversian remodeling reduce their translational applicability for evaluating large defects or load-bearing sites. Rabbit models provide an intermediate platform for testing medium-sized defects, with more clearly defined critical-size thresholds and partial Haversian remodeling. Dogs offer clinically realistic surgical handling, human-like bone remodeling, and the ability to standardize complex intraoral defects, although their use is declining because of ethical and regulatory considerations. Minipigs and pigs show the closest correspondence to human craniofacial bone structure, density, and biomechanics, making them highly valuable for late-stage translational validation. However, their strong healing potential and large body size require carefully standardized defect designs and rigorous experimental controls. Across all species, acute versus chronic defects, infected versus noninfected environments, and systemically healthy versus compromised conditions substantially influence healing outcomes. Standardized defect dimensions, appropriate observation periods, and robust quantitative assessment methods are critical for ensuring reproducibility. An understanding of species-specific healing patterns and methodological considerations enables investigators to design preclinical experiments that more closely reflect clinical scenarios and support the development of predictable regenerative therapies.
PURPOSE:This multicenter study aimed to evaluate the diagnostic performance and clinical feasibility of a deep learning (DL) model for assessing periodontitis progression using serial panoramic radiographs. METHODS:A total of 7,106 panoramic images from 1,378 patients were retrospectively collected from 3 university hospitals. A YOLOv8-based DL model was trained separately for indirect (single-timepoint) and direct (serial) assessments to segment and classify alveolar bone levels. Diagnostic performance metrics, including accuracy, sensitivity, specificity, and the area under the receiver operating characteristic (ROC) curve (AUC), were evaluated for both the DL model and human evaluators. Comparative ROC analyses and assessment-time comparisons were conducted to evaluate discriminative ability and efficiency. RESULTS:The DL model demonstrated high diagnostic accuracy, particularly for indirect grading (accuracy, 89.6%; AUC, 0.913), and outperformed both interns and periodontal residents. Direct grading also performed well (accuracy, 79.5%; AUC, 0.854), although this performance was slightly lower due to the greater complexity of evaluating serial images. The DL model outperformed human evaluators (accuracy range, 38.0%-80.0%) while requiring significantly less assessment time (91.0±6.8 seconds vs. 143.7±33.6 seconds for interns). CONCLUSIONS:This multicenter study demonstrates that DL-based assessment of periodontitis progression using serial panoramic radiographs achieves high diagnostic accuracy (89.6% and 79.5% for indirect and direct assessment, respectively) while markedly improving time efficiency. This approach has strong potential as a standardized adjunctive diagnostic tool for periodontal clinical decision-making.
PURPOSE:The primary objective in treating peri-implantitis is the elimination of biofilm from the implant surface. This study aimed to measure the width of the contaminant-free zone in implants removed from patients and to determine the extent of surface decontamination achieved during peri-implantitis treatment. METHODS:Patients presenting with the chief complaint of implant discomfort were recruited. The inclusion criterion was implant removal due to biological or mechanical complications, including marginal bone loss extending to the apical third of the implant fixture, fixture tearing, or fixture fractures. Removed implants were analyzed using scanning electron microscopy (SEM). The width of the contaminant-free zone was defined as the distance from the apical end of the biofilm to the apical and coronal first bone-to-implant contact, measured with a caliper in conjunction with SEM. The mean width of the contaminant-free zone was compared across implant characteristics using the independent t-test. RESULTS:A total of 49 implants were removed from 39 patients. The mean width of the contaminant-free zone was 0.66±0.67 mm (range, 0-3.0 mm). No significant differences in the width of the contaminant-free zone were observed according to sex, age, presence of diabetes, smoking habits, implant location, reason for removal, fixture type, fixture length, or prosthetic type (P>0.05). No variable significantly affected the width of the contaminant-free zone. CONCLUSIONS:The width of the contaminant-free zone was found to be less than 1 mm. Therefore, precise and delicate debridement of all fixture surfaces above the remaining marginal bone is required during peri-implantitis treatment.
PURPOSE:Periodontitis (PD) and rheumatoid arthritis (RA) share inflammatory pathways, with interleukin-6 (IL-6) and microRNA-155 (miR-155) implicated as key mediators. This study quantified salivary IL-6 and serum miR-155 levels across 4 groups (PD only, RA only with a healthy periodontium, comorbid PD+RA, and healthy controls) and examined their associations with clinical severity indices of both diseases. METHODS:This cross-sectional case-control study enrolled 120 participants (30 per group). Periodontitis was diagnosed according to the 2017 American Academy of Periodontology/European Federation of Periodontology classification, and RA was diagnosed according to the 2010 American College of Rheumatology/European League Against Rheumatism criteria. Salivary IL-6 and serum miR-155 were measured using quantitative real-time polymerase chain reaction. RESULTS:Combined salivary IL-6 and serum miR-155 expression differed significantly across groups (multivariate analysis of covariance, Pillai's trace=0.892, P<0.001), with the highest levels observed in the comorbid group. Both biomarkers showed strong positive correlations with periodontal clinical parameters (Spearman ρ=0.704-0.958) and moderate-to-strong correlations with RA disease activity measures (ρ=0.391-0.782; all P<0.001). The periodontal severity composite score explained 94.3% of the variance and correlated most strongly with IL-6 (ρ=0.958). Receiver operating characteristic analyses yielded area under the curve (AUC) values of 0.75-1.00, including perfect discrimination (AUC=1.00) in multiple comparisons. CONCLUSIONS:Salivary IL-6 and serum miR-155 were strongly associated with the presence and severity of both PD and RA and were markedly elevated in comorbid cases, supporting their potential as biomarkers. Longitudinal studies are needed to establish temporality and causality.
