Association of Peri-Implant Keratinized Mucosa Width and Mucosal Thickness with Early Bone Loss: A Cross-Sectional Study.

Objective: The objective of this study was to evaluate the effects of keratinized mucosa width (KMW) and mucosal thickness (MT) around dental implants on marginal bone loss (MBL). The evaluation was performed one year after loading by comparing clinical, radiographic, and biochemical parameters. Methods: The study included 87 implants in 87 patients undergoing regular follow-ups without hard or soft tissue augmentation one year after loading. Clinical measurements included plaque index (PI), gingival index (GI), bleeding on probing (BoP), probing depth (PD), KMW, and MT. MBL was assessed with periapical radiography. The peri-implant crevicular fluid (PICF) was analyzed for tumor necrosis factor-alpha (TNF-α), receptor activator of nuclear factor-kB ligand (RANKL), osteoprotegerin (OPG), and microRNA-27a. Results: The MBL of implants with thin MT (<2 mm) was higher than that of implants with thick MT (≥2 mm) (p < 0.05). A significant negative correlation (r: -0.217) was established between MT and MBL. No significant association was found between KMW and MBL (p > 0.05). No significant associations was found between KMW and MT with TNF-α, RANKL, OPG and RANKL/OPG (p > 0.05), with the exception of increased microRNA-27a levels in implants with KMW ≥ 2 mm (p < 0.05). Conclusions: Implants with a thick MT had a lower MBL. There may be an association between adequate KMW and high miRNA-27a levels. The relationship between MBL and miRNA-27a remains unclear.

Small extracellular vesicles derived from lipopolysaccharide-preconditioned dental follicle cells inhibit cell apoptosis and alveolar bone loss in periodontitis.

OBJECTIVE: This study aimed to explore the effects of small extracellular vesicles derived from lipopolysaccharide-preconditioned dental follicle cells (L-D-sEV) on periodontal ligament cells from periodontitis affected teeth (p-PDLCs) in vitro and experimental periodontitis in mice. DESIGN: In vitro, the biological function of p-PDLCs and the underlying molecular mechanism were investigated by flow cytometry, Western blot, and quantitative real-time PCR (qRT-PCR) analysis. Eighteen-eight-week-old male C57BL/6 mice were randomly divided into three groups: control (Con), periodontitis (Peri), and L-D-sEV groups. Mice periodontitis model was induced by placing the 5-0 silk thread (around the maxillary second molar) and P.gingivalis (1 ×107 CFUs per mouse). In vivo, the alveolar bone loss, osteoclast activity, and macrophage polarization were measured by micro-computed tomography and histological analysis. RESULTS: In vitro, the RANKL/OPG ratio and phosphorylation of JNK and P38 protein levels of p-PDLCs were significantly decreased after L-D-sEV administration. Besides, flow cytometry and qRT-PCR analysis showed that L-D-sEV reduced apoptosis of p-PDLCs, down-regulated apoptosis-related genes Caspase-3 and BCL-2-Associated X expression, and up-regulated B-cell lymphoma-2 gene levels. In vivo, L-D-sEV administration significantly reduced alveolar bone loss, inhibited osteoclast activity, and induced M2 polarization. The histological analysis showed that iNOS/CD206, RANKL/OPG, p-JNK/JNK, and p-P38/P38 ratios were significantly lower in the L-D-sEV group than in the Peri group. CONCLUSIONS: L-D-sEV administration alleviated alveolar bone loss by mediating RANKL/OPG-related osteoclast activity and M2 macrophage polarization, alleviating p-PDLCs apoptosis and proliferation via the JNK and P38 pathways.

Fabrication of a mandibular implant-retained overdenture using an existing subperiosteal implant: A clinical report.

A 64-year-old edentulous woman with a mandibular fracture received a subperiosteal implant for fracture fixation and dental rehabilitation. However, the ball abutments were submerged by the soft tissue because they were too short. Therefore, we designed a connector to lengthen the attachment and achieve adequate stability and retention for the overdenture.

Marginal Bone Loss in Posterior Implants Placed at Different Levels and Different Prosthetic Designs: A Retrospective Study."

Various factors influence marginal bone loss following implant placement. This study explored the association between marginal bone loss and posterior implants positioned at different bone levels. Computer records and radiographs of patients with at least two adjacent implants were retrieved. Cases were categorized into non-splinted prosthesis and splinted prosthesis groups. Radiographic measurements were conducted at the time of abutment placement (T0), 1-3 years follow-up (T1), and the last visit (T2), measuring the vertical distance between adjacent implants. Multilevel linear regression models using generalized estimating equations were employed, with a significance level set at 5% (α=0.05). Fifty-six patient records were included, comprising 120 implants: 84 non-splinted (70%) and 36 splinted (30%). In the non-splinted group, marginal bone loss progression significantly depended on crestal height differences. For the mesial sides of posterior implants, marginal bone loss measured 1.0 ± 0.6 mm from T0 to T1, 2.4 ± 1.1 mm from T1 to T2, and 3.4 ± 1.2 mm from T0 to T2. Similarly, the distal sides of the most anteriorly placed implant exhibited marginal bone loss of 1.0 ± 0.7 mm from T0 to T1, 2.4 ± 1.0 mm from T1 to T2, and 3.5 ± 1.2 mm from T0 to T2. Non-splinted implants demonstrated a higher progression of marginal bone loss. This study suggests that non-splinted implants may lead to a more pronounced progression of marginal bone loss, particularly concerning crestal height differences, underscoring the need for further research.

Melatonin Decreases Alveolar Bone Loss in Rats with Experimental Periodontitis and Osteoporosis: A Morphometric and Histopathologic Study.

BACKGROUND: Periodontitis and post-menopausal osteoporosis include common chronic bone disorders worldwide, with similar etiopathogenetic events. This study evaluated the effect of systemic melatonin administration on the alveolar bone destruction of periodontitis progression in an experimental periodontitis model in osteoporotic rats. METHODS: Forty-four Wistar rats were randomly divided into six experimental groups: control (C; n = 6); osteoporosis (O; n = 6); ligated periodontitis (LP; n = 8); osteoporosis- and periodontitis-induced (O+LP; n = 8); osteoporosis- and periodontitis-induced through 30 mg/kg/day melatonin administration (ML30; n = 8); and osteoporosis- and periodontitis-induced through 50 mg/kg/day melatonin administration (ML50; n = 8). The rats underwent bilateraloophorectomy and were maintained for 4 months to induce osteoporosis. After 4 months, 4-0 silk ligatures were placed submarginally around the mandibular first molar of each rat to induce experimental periodontitis, and melatonin was administered in the ML30 and ML50 groups for 30 days. Changes in alveolar bone levels were clinically measured, and tissues were histopathologically examined. RESULTS: Osteoclastic activity in the LP and O+LP groups was significantly higher than in the other groups (p < 0.05), but was similar in the C, O, and ML30 groups (p > 0.05). RANKL activity was the highest in the O+LP group, while melatonin decreased RANKL activity in the melatonin-administered groups (p < 0.05). Systemically administered melatonin significantly decreased alveolar bone loss in the ML30 and ML50 groups compared with that in the periodontitis groups (p < 0.05). CONCLUSIONS: Melatonin inhibited alveolar bone destruction by decreasing the RANKL expression and inflammatory cell infiltration and increased osteoblastic activity in a rat model with osteoporosis and periodontitis.

Radiographic evaluation of the distance between the restoration margin and the alveolar bone crest in dental implant patients: A retrospective study.

OBJECTIVES: The recently introduced Implant Disease Risk Assessment (IDRA) identifies a restoration margin-alveolar bone crest (RM-AC) distance of less than 1.5 mm as a key risk factor for peri­implant disease among eight major risk factors. This study evaluated the impact of the RM-AC distance on marginal bone loss (MBL) through radiographic analysis. METHODS: This retrospective cross-sectional study included 77 partially edentulous patients (39 females and 38 males, aged 22 to 76 years) with 202 platform-switched conical connection implants, cement-retained, implant-supported fixed restorations, and bone-level implants placed between 2016 and 2021. Dental implants were followed for least 6 to 36 months at follow up functional loading. Study participants were categorized into Group A (RM-AC distance ≤ 1.5 mm, n = 69) and Group B (RM-AC distance > 1.5 mm, n = 133). Twelve patients in Group B and five patients in Group A had no history of periodontal disease. The MBL was measured radiographically from the most coronal point of the implant shoulder to the alveolar bone, and the RM-AC distance was measured from the restoration margin to the alveolar crest. Multinomial logistic regression analysis was used for statistical evaluation. RESULTS: The incidence of MBL in Group A was statistically significant and 3.42 times higher than that in Group B. The rate of MBL in periodontitis Stage 4 was found to be 26.31 times higher than that in periodontitis Stage 2. The incidence of MBL was 6.097 and 5.02 times higher with increasing implant diameter and length, respectively. CONCLUSION: This study conclusively demonstrates that RM-AC distance ≤ 1.5 significantly increases the risk of MBL, particularly in patients with a history of periodontal disease. CLINICAL SIGNIFICANCE: This study highlights the critical role of maintaining an RM-AC distance greater than 1.5 mm in the prevention of MBL, particularly in patients with a history of periodontal disease. Since implant diameter and length have a significant impact on the risk of MBL, it emphasizes that implant demographics should also be carefully evaluated.

Prevalence and Severity of Circumferential Alveolar Bone Loss Using CBCT Images: A Retrospective Study of 20,620 Surfaces of 5155 Teeth.

Periodontal disease is a site-specific disease affecting the supporting tissues of the teeth. It is useful for the clinician to have information about the prevalence and severity of alveolar bone loss (ABL) according to the site, location, and position of the teeth for a better treatment plan and expected prognosis. This study aimed to assess the prevalence and severity of ABL at mesial, distal, buccal and lingual sites of teeth in different locations, positions and sides of the dentition. The ABL of 20,620 sites of 5155 teeth in 212 patients was assessed using cone-beam computed tomography from the cemento-enamel junction to the crest of the alveolar bone. The prevalence of ABL was higher in the interproximal sites as well as anterior and mandibular teeth compared to their counterparts. Buccal sites and anterior teeth revealed higher ABL levels than the other tooth sites and posterior teeth, respectively. Furthermore, associations in the severity of ABL were observed between distal and mesial sites, buccal and lingual sites, maxillary and mandibular teeth, anterior and posterior teeth, and right and left sides. This study showed that the prevalence and severity of ABL differ from one tooth site to another and according to the tooth's location in the dentition. Higher prevalences were found in the interproximal sites, anterior teeth and mandibular teeth; higher ABL was found in buccal and distal sites, with the strongest associations between distal and mesial sites, buccal and lingual sites, and right and left sides.

Correlation between whole salivary prostaglandin E2 and hemoglobin A1c levels among type-2 diabetic and non-diabetic patients with periodontal inflammation.

BACKGROUND: It is hypothesized that whole salivary prostaglandin E2 (PgE2) levels are higher in patients with type-2 diabetes mellitus (type-2 DM) than non-diabetic individuals with periodontal inflammation; and that whole salivary expression of PgE2 is correlated with hemoglobin A1C (HbA1c) levels. The aim of the present study was to compare whole salivary PgE2 levels among patients with type-2 DM and non-diabetic individuals with periodontal inflammation. METHODS: Sociodemographic data, duration since the diagnosis and management of type-2 DM, most recent hemoglobin A1C (HbA1c level), and any familial history of DM was retrieved from patient's healthcare records. Participants were divided into four groups: Group-1: type-2 diabetics with periodontal inflammation; Group-2: type-2 diabetics without periodontal inflammation; Group-3: non-diabetics with periodontal inflammation; and Group-4: non-diabetics without periodontal inflammation. Plaque and gingival indices (PI and GI), probing depth (PD), clinical attachment loss (CAL) and marginal bone loss (MBL) were measured. Unstimulated whole saliva samples were collected and PgE2 levels were measured. Group-comparisons were done and P < 0.05 were considered statistically significant. RESULTS: One-hundred-sixty individuals were included. Mean HbA1c levels were higher in Group-1 than groups 2 (P < 0.05), 3 (P < 0.05) and 4 (P < 0.05). The PI (P < 0.05), GI (P < 0.05) and PD (P < 0.05) were higher in Group-1 than groups 2 and 4. The CAL was higher in Group-1 than groups 2 (P < 0.05) and 3 (P < 0.05). The PD (P < 0.05), PI (P < 0.05) and GI (P < 0.05) were higher in Group-3 than Group-4. The MBL was higher in Group-1 than groups 2 (P < 0.05), 3 (P < 0.05) and 4 (P < 0.05). The PgE2 levels were higher in Group-1 than groups 2 (P < 0.05), 3 (P < 0.05) and 4 (P < 0.05). CONCLUSION: Hyperglycemia in patients with type-2 DM is associated with increased expression of whole salivary PgE2 levels and worsened periodontal inflammation compared with individuals with well-controlled type-2 DM and non-diabetic individuals.

The impact of arthritogenic viruses in oral tissues.

Arthritis and periodontitis are inflammatory diseases that share several immunopathogenic features. The expansion in the study of virus-induced arthritis has shed light on how this condition could impact other parts of the human body, including the mouth. Viral arthritis is an inflammatory joint disease caused by several viruses, most notably the alphaviruses Chikungunya virus (CHIKV), Sindbis virus (SINV), Ross River virus (RRV), Mayaro virus (MAYV), and O'nyong'nyong virus (ONNV). These viruses can induce an upsurge of matrix metalloproteinases and immune-inflammatory mediators such as Interleukin-6 (IL6), IL-1ß, tumor necrosis factor, chemokine ligand 2, and receptor activator of nuclear factor kappa-B ligand in the joint and serum of infected individuals. This can lead to the influx of inflammatory cells to the joints and associated muscles as well as osteoclast activation and differentiation, culminating in clinical signs of swelling, pain, and bone resorption. Moreover, several data indicate that these viral infections can affect other sites of the body, including the mouth. The human oral cavity is a rich and diverse microbial ecosystem, and viral infection can disrupt the balance of microbial species, causing local dysbiosis. Such events can result in oral mucosal damage and gingival bleeding, which are indicative of periodontitis. Additionally, infection by RRV, CHIKV, SINV, MAYV, or ONNV can trigger the formation of osteoclasts and upregulate pro-osteoclastogenic inflammatory mediators, interfering with osteoclast activation. As a result, these viruses may be linked to systemic conditions, including oral manifestations. Therefore, this review focuses on the involvement of alphavirus infections in joint and oral health, acting as potential agents associated with oral mucosal inflammation and alveolar bone loss. The findings of this review demonstrate how alphavirus infections could be linked to the comorbidity between arthritis and periodontitis and may provide a better understanding of potential therapeutic management for both conditions.

Gli1+ Periodontal Mesenchymal Stem Cells in Periodontitis.

Periodontal mesenchymal stem cells (MSCs) play a crucial role in maintaining periodontium homeostasis and in tissue repair. However, little is known about how periodontal MSCs in vivo respond under periodontal disease conditions, posing a challenge for periodontium tissue regeneration. In this study, Gli1 was used as a periodontal MSC marker and combined with a Gli1-cre ERT2 mouse model for lineage tracing to investigate periodontal MSC fate in an induced periodontitis model. Our findings show significant changes in the number and contribution of Gli1+ MSCs within the inflamed periodontium. The number of Gli1+ MSCs that contributed to periodontal ligament homeostasis decreased in the periodontitis-induced teeth. While the proliferation of Gli1+ MSCs had no significant difference between the periodontitis and the control groups, more Gli1+ MSCs underwent apoptosis in diseased teeth. In addition, the number of Gli1+ MSCs for osteogenic differentiation decreased during the progression of periodontitis. Following tooth extraction, the contribution of Gli1+ MSCs to the tooth socket repair was significantly reduced in the periodontitis-induced teeth. Collectively, these findings indicate that the function of Gli1+ MSCs in periodontitis was compromised, including reduced contribution to periodontium homeostasis and impaired injury response.

Implant-prosthetic rehabilitation of the atrophic posterior mandible with additively manufactured custom-made subperiosteal implants: a cohort study.

The aim of this study was to retrospectively analyse a series of patients with posterior mandibular atrophy rehabilitated with custom-made subperiosteal implants. The study included patients with severe posterior mandibular atrophy who had undergone rehabilitation with subperiosteal implants between September 2018 and August 2022 in the Maxillofacial Surgery Operative Unit of the University Hospital of Sassari. Complications and the success rate were reviewed. Data from 30 implants placed in 17 patients were included and analysed. There were no major complications during the surgeries. The main postoperative sequela was oedema, which was reported as moderate by most patients and had completely regressed within 10 days of surgery. No partial or complete exposures, infections, or loss of the implants were detected during follow-up (average follow-up 22.5 months). Control computed tomography scans, performed at 6 months and then annually in all cases, did not show significant bone loss below the abutments, displacement of the implants, or loss or loosening of the osteosynthesis screws. Subperiosteal implants may represent a safe and reliable technique for the rehabilitation of severe atrophy of the posterior mandible. Prospective studies with a long follow-up will be needed to establish the long-term results of this type of implant-prosthetic rehabilitation.

Empirically derived dietary patterns in relation to periodontitis and number of teeth among Norwegian adults.

OBJECTIVES: To explore dietary patterns in relation to periodontitis and number of teeth. DESIGN: A cross-sectional study. SETTING: We used data from the seventh survey of the Tromsø Study in Norway, 2015-2016. Three periodontitis groups were compared: (i) no periodontitis/slow bone loss; (ii) moderate bone loss; and (iii) rapid bone loss. Number of teeth was categorised as 25-28, 20-24 and ≤ 19. Dietary patterns were identified by principal component analysis. Multiple logistic regression was applied to examine associations between tertiles of dietary pattern scores and periodontitis, and between these same tertiles and number of teeth. PARTICIPANTS: 1487 participants (55·5 % women) aged 40-79 years who were free of major chronic diseases, attended an oral health examination and completed a FFQ. RESULTS: Four dietary patterns were identified, which explained 24 % of the total variability in food intake: fruit and vegetables, Westernised, meat/fish and potatoes, and refined grain and dessert. The fruit and vegetables pattern was inversely associated with periodontitis characterised by rapid bone loss when compared with no periodontitis/slow bone loss (OR tertile 3 v. 1 0·49, 95 % CI: 0·25, 0·98). Participants who were in the highest tertile of the refined grain and dessert pattern (tertile 3 v. 1) had 2·38- and 3·52-fold increased odds of having ≤ 19 than 20-24 and 25-28 teeth, respectively. CONCLUSION: Out of four identified dietary patterns, only the fruit and vegetables pattern was negatively associated with advanced periodontitis. A more apparent positive association was observed between the refined grain and dessert pattern and having fewer teeth (≤ nineteen teeth).

Blocking CXCR1/2 attenuates experimental periodontitis by suppressing neutrophils recruitment.

Periodontitis (PD) is a common chronic oral inflammatory disease that cause alveolar bone loss. Current strategies for bone regeneration achieve limited results in PD. The aberrant host osteoimmunity to pathogenic bacteria is responsible for the destruction of alveolar bone in PD. We aimed to investigate the distinctive activity of immune cells in PD to create more effective and precise therapeutic approaches for treating PD. In this study, we revealed that neutrophils in the inflamed alveolar bone of PD patients expressed higher levels of CXCR1/2 and had a stronger pro-inflammatory capacity and chemotactic ability than that in healthy individuals. Suppressing the recruitment of neutrophils to inflamed sites with the CXCR1/2 inhibitor reparixin reduced alveolar bone loss in PD mice. In this study, we not only revealed that neutrophils exhibit a heterogeneously stronger pro-inflammatory capacity in the inflamed alveolar bone of PD patients but also provided a precise therapeutic treatment for PD involving the suppression of neutrophil recruitment.

To intrude or not to intrude? A systematic review of the controversy surrounding orthodontic intrusion on reduced periodontium.

OBJECTIVE: The main objective of this review was to evaluate the effects of orthodontic intrusion on patients with reduced periodontium. Additionally, this review aims to explore the potential for attachment gain and tissue regeneration in these patients and identify optimal therapeutic conditions to mitigate any negative effects of intrusion. METHODS: A systematic review was conducted according to the PRISMA 2020 statement. Duplicate electronic searches of the PubMed, Cochrane, EMC Premium, and Science Direct databases were performed by two independent reviewers. Data extraction and quality assessments, including risk of bias evaluation using the Cochrane and ROBINS-I tools were conducted. RESULTS: From an initial pool of 418 articles, 29 were selected after title and abstract screening for full-text review. Following thorough full-text reading, 15 studies were ultimately included in the analysis. The total number of patients included in the studies is 528, who underwent orthodontic intrusion on reduced periodontium. Studies indicated a decrease in periodontal pocket depth and an increase in clinical attachment with ortho-periodontal treatment. Alveolar bone level outcomes varied, showing both increases and losses. Authors generally observed improved papillary regeneration and reduced gingival recessions. CONCLUSION: Clinical studies involving combined ortho-periodontal treatment showed that orthodontic intrusion on a reduced but healthy periodontium can be considered a beneficial treatment for the periodontium, provided that potential adverse effects are carefully monitored.

Comparison of deep learning methods for the radiographic detection of patients with different periodontitis stages.

OBJECTIVES: The objective of this study is to assess the accuracy of computer-assisted periodontal classification bone loss staging using deep learning (DL) methods on panoramic radiographs and to compare the performance of various models and layers. METHODS: Panoramic radiographs were diagnosed and classified into 3 groups, namely "healthy," "Stage1/2," and "Stage3/4," and stored in separate folders. The feature extraction stage involved transferring and retraining the feature extraction layers and weights from 3 models, namely ResNet50, DenseNet121, and InceptionV3, which were proposed for classifying the ImageNet dataset, to 3 DL models designed for classifying periodontal bone loss. The features obtained from global average pooling (GAP), global max pooling (GMP), or flatten layers (FL) of convolutional neural network (CNN) models were used as input to the 8 different machine learning (ML) models. In addition, the features obtained from the GAP, GMP, or FL of the DL models were reduced using the minimum redundancy maximum relevance (mRMR) method and then classified again with 8 ML models. RESULTS: A total of 2533 panoramic radiographs, including 721 in the healthy group, 842 in the Stage1/2 group, and 970 in the Stage3/4 group, were included in the dataset. The average performance values of DenseNet121 + GAP-based and DenseNet121 + GAP + mRMR-based ML techniques on 10 subdatasets and ML models developed using 2 feature selection techniques outperformed CNN models. CONCLUSIONS: The new DenseNet121 + GAP + mRMR-based support vector machine model developed in this study achieved higher performance in periodontal bone loss classification compared to other models in the literature by detecting effective features from raw images without the need for manual selection.

Guided Customization and Fixation of Allogenic Cortical Lamina in Alveolar Bone Regeneration. A Case Report.

Bone reconstruction surgeries such as the autogenous and allogenic shell techniques where cortical laminates are used to regenerate bone defects, requires time and expertise to adapt and fix the laminated cortical blocks onto the defect area. This case report illustrates the process of customizing and fixing an allogenic cortical laminate (ACL) to reconstruct a horizontal bone defect with guided surgical stents. Two types of surgical stents were designed: one to aid in cutting a prefabricated ACL into the desired shape for the defect to be regenerated, and the other type of stent, was used to assist in the positioning and fixation of the resulting laminates. These stents enabled the clinician to regenerate a horizontal defect with reduced surgical time, increased precision and safety during laminate fixation. After 5 months of healing a dental implant could be placed in the regenerated site. The use of surgical stents in this type of bone regeneration surgeries can be helpful specially in more complex bone defects where precision is key. Further clinical studies are needed to validate this technique.

Clinical evaluation of 3.0-mm narrow-diameter implants: a retrospective study with up to 5 years of observation.

PURPOSE: This study aimed to evaluate the clinical outcomes of a single type of narrow-diameter implant (NDI) by investigating its survival rate and peri-implant marginal bone loss (MBL). In addition, variables possibly related to implant survival and MBL were investigated to identify potential risk factors. METHODS: The study was conducted as a retrospective study involving 49 patients who had received 3.0-mm diameter TSIII implants (Osstem Implant Co.) at Seoul National University Dental Hospital. In total, 64 implants were included, and dental records and radiographic data were collected from 2017 to 2022. Kaplan-Meier survival curves and a Cox proportional hazard model were used to estimate the implant survival rate and to investigate the effects of age, sex, jaw, implant location, implant length, the stage of surgery, guided bone regeneration, type of implant placement, and the surgeon's proficiency (resident or professor) on implant survival. The MBL of the NDIs was measured, and the factors influencing MBL were evaluated. RESULTS: The mean observation period was 30.5 months (interquartile range, 26.75-45 months), and 6 out of 64 implants failed. The survival rate of the NDIs was 90.6%, and the multivariate Cox regression analysis showed that age was associated with implant failure (hazard ratio, 1.17; 95% confidence interval, 1.04-1.31, P=0.01). The mean MBL was 0.44±0.75 mm, and no factors showed statistically significant associations with greater MBL. CONCLUSIONS: NDIs can be considered a primary alternative when standard-diameter implants are unsuitable. However, further studies are required to confirm their long-term stability.

The impact of Resolvin E1 on bone regeneration in critical-sized calvarial defects of rat model-A gene expression and micro-CT analysis.

OBJECTIVE: To investigate, in vivo, the effect of local application of Resolvin E1 (RvE1) on the bone regeneration of critical-size defects (CSDs) in Wistar rats utilizing gene expression and micro-computed tomographic (micro-CT) analysis. BACKGROUND: The inflammation-resolving actions of RvE1 are well established. The molecular mechanism of its bone-regenerative actions has been of significant interest in recent years; however, there is limited information regarding the same. MATERIALS AND METHODS: Thirty Wistar rats with a 5 mm induced critical-size calvarial defect were randomly allocated into four groups: no treatment/negative control (n = 5), treatment using bovine bone grafts/positive control (n = 5), treatment using local delivery of RvE1 (n = 11) and treatment using RvE1 mixed with bovine bone graft (n = 9). After 4 weeks, RNA isolation, complementary DNA synthesis and real-time polymerase chain reaction were used for genetic expression of alkaline phosphatase (ALP), osteocalcin (OCN) and osteopontin (OPN). The rats were sacrificed after 12 weeks and micro-CT imaging was performed to analyse the characteristics of the newly formed bone (NFB). The data were analysed using ANOVA and the least significant difference tests (α ≤ .05). RESULTS: The RvE1 + bovine graft group had statistically highest mean NFB (20.75 ± 2.67 mm3 ) compared to other groups (p < .001). Similarly, RvE1 + bovine graft group also demonstrated statistically highest mean genetic expression of ALP (31.71 ± 2.97; p = .008) and OPN (34.78 ± 3.62; p < .001) compared to negative control and RvE1 groups. CONCLUSION: Resolvin E1 with adjunct bovine bone graft demonstrated an enhanced bone regeneration compared to RvE1 or bovine graft alone in the calvarial defect of Wistar rats.

Interleukin-17 alleviates erastin-induced alveolar bone loss by suppressing ferroptosis via interaction between NRF2 and p-STAT3.

AIM: To investigate the relationship between interleukin-17 (IL-17), ferroptosis and osteogenic differentiation. MATERIALS AND METHODS: We first analysed the changes in ferroptosis-related molecules in experimental periodontitis models. The effects of erastin, a small-molecule ferroptosis inducer, and IL-17 on alveolar bone loss and repair in animal models were then investigated. Primary mouse mandibular osteoblasts were exposed to erastin and IL-17 in vitro. Ferroptosis- and osteogenesis-related genes and proteins were detected. Further, siRNA, immunofluorescence co-localization and immunoprecipitation were used to confirm the roles of the nuclear factor erythroid-2-related factor 2 (NRF2) and phosphorylated signal transducer and activator of transcription 3 (p-STAT3), as well as their interaction. RESULTS: The levels of NRF2, glutathione peroxidase 4 and solute carrier family 7 member 11 were lower in the ligated tissues than in normal periodontal tissues. Alveolar bone loss in an in vivo experimental periodontitis model was aggravated by erastin and alleviated by IL-17. In vitro, IL-17 ameliorated erastin-inhibited osteogenic differentiation by reversing ferroptosis. Altered NRF2 expression correlated with changes in ferroptosis-related molecules and osteogenesis. Furthermore, the physical interaction between NRF2 and p-STAT3 was confirmed in the nucleus. In IL-17 + erastin-stimulated osteoblasts, the p-STAT3-NRF2 complex might actively participate in the downstream transcription of ferroptosis- and osteogenesis-related genes. CONCLUSIONS: IL-17 administration conferred resistance to erastin-induced osteoblast ferroptosis and osteogenesis. The possible mechanism may involve p-STAT3 directly interacting with NRF2.

Immediate implant placement for chronic peri-apical periodontitis in the molar region: a randomised controlled trial.

The aim of this study was to evaluate the feasibility of immediate implantation for chronic peri-apical periodontitis in the molar region. Seventy-four molars were selected and allocated randomly to two groups. The experimental group (n = 38) received immediate implantation by flap surgery and the control group (n = 36) received delayed implantation. CBCT was performed immediately after surgery (T1) and 12 months after the permanent repair (T3). The implant survival rate at T3 was 100% in both groups. There was no significant difference in buccal or lingual vertical marginal bone loss between the groups (P = 0.515, P = 0.736). However, the buccal horizontal margin bone loss was significantly greater in the experimental group: 0.98 ± 0.34 mm vs 0.77 ± 0.27 mm in the control group (P = 0.003). In the experimental group, the highest point of buccal and lingual implant-bone contact increased at T3. The buccal and lingual jump gap widths were 3.21 ± 1.10 mm and 2.92 ± 1.01 mm at T1, and CBCT showed no jump gap around the implants at T3. The clinical outcomes showed immediate implantation to be feasible for chronic peri-apical periodontitis in the molar region.