Necroptosis has a crucial role in the development of chronic periodontitis.

Background and aim: Periodontitis is a non-communicable chronic inflammatory disease that affects the entire periodontium and its severe types cause irreparable destruction. The purpose of this study was to determine the type of cell death in chronic periodontitis (CP) with the expression of receptor-interacting protein kinase (RIPK) type1 and RIPK3 genes. Materials and methods: This cross-sectional study was carried out from September 2019 to 2020. The samples (38 participants) were divided into two groups: 20 recently diagnosed CP patients and 18 healthy individuals. Participants' data was collected in the periodontology Department, Dental school, Mashhad University of Medical Sciences and sent to the Immunology Lab for assessment of RIPK1 and RIPK3 expressions using quantitative real time-PCR. Results: The study sample consisted of 30 females (78.9%) and 8 males (21.1%) with a mean age of 34 ± 5 years. The expression of the genes of interest in CPs exhibited an opposite pattern. Although, RIPK3 gene expression was significantly greater in CP patients compared to the control group (P = 0.024), the expression of RIPK1 decreased (p < 0.001). Moreover, no significant correlation was observed between age and gender with these molecules in CPs. Conclusion: The RIPK3 selectively contributes to necroptosis, therefore, it seems that RIPK3-mediated necroptosis is involved in chronic periodontitis. RIPK1 also participates in necroptosis, but mostly in apoptosis. Therefore, necroptosis as an unprogrammed inflammatory cell death induced by pathogenic damages seems to be another mechanism complicated in periodontitis and could be used as a novel target for CP therapy.

Effect of Acellular Dermal Matrix Placement Simultaneous with Implant Placement on Vertical Soft Tissue Thickness: A Randomized Controlled Clinical Trial.

Acellular dermal matrix (ADM) is commonly used for soft tissue augmentation in root coverage, increasing the width of keratinized gingiva or vestibular depth, or filling the localized alveolar bone defects. This parallel-design randomized controlled clinical trial assessed the effect of ADM membrane placement simultaneous with implant placement on vertical soft tissue thickness. A total of 25 submerged implants were placed in 25 patients (8 men, 17 women) with vertical soft tissue thickness < 3 mm at the surgical site. Patients were randomized into two groups: The intervention group (n = 13) received ADM over the implant for soft tissue augmentation, while no augmentation was performed for the control group (n = 12). After 3 months, healing abutments were placed, and the soft tissue thickness at the surgical site was measured again with a periodontal probe in both groups. Data were analyzed using Mann-Whitney and Wilcoxon tests. All 25 patients were successfully treated. The presurgical vertical soft tissue thickness was 2 mm and 1.92 mm in the control and test groups, respectively (P > .05). These values changed to 1.83 mm and 2.69 mm, respectively, after the intervention. The mean gain in soft tissue thickness was 0.76 mm in the test group, and the difference between groups was statistically significant (P < .05). ADM membrane can be successfully used to augment vertical soft tissue thickness simultaneous with implant placement.

Matrix Metalloproteinase-3 but Not Matrix Metalloproteinase-9, Implicated in the Manifestation of Chronic Periodontitis.

Background: Periodontal disease is an inflammatory condition affecting the tooth's supporting tissues, resulting in gradual loss of periodontal ligament (PDL), alveolar bone, and gum resorption. Neutrophil and monocyte/macrophage, destructive proteases like matrix metalloproteinase (MMP)-3 and MMP-9 play pivotal roles in such lesions in periodontitis. Therefore, this study aims to compare the level of MMP-3 and MMP-9 gene expression in patients with or without periodontitis in an Iranian population. Methods: This cross-sectional study was carried out on 22 chronic periodontitis patients and 17 healthy control subjects referred to the department of periodontology, Mashhad Dental School. In both groups, the gingival tissue was removed during surgery and transferred to the Molecular Biology Laboratory for MMP-3 and MMP-9 gene expression evaluation. The qRT-PCR, TaqMan method was used for gene expression assessments. Results: The average age of periodontitis patients was 33± 5 years, and in controls, 34.7± 6 with no significant differences. The mean MMP-3 expression in periodontitis patients was 146.67±38.7, and in controls, 63.4±9.1. The difference was statistically significant (P=0.04). The mean expression of MMP-9 in periodontitis patients and controls were 103.8± 21.66 and 87.57± 16.05, respectively. Although the target gene expression in patients was higher, the difference was insignificant. Furthermore, there was not any significant correlation between age or gender with the expression of MMP3 or MMP9. Conclusion: The study demonstrated that the MMP3 seems to have a destructive impact on the gingival tissue in chronic periodontitis, but not MMP9.

CBCT evaluation of buccal bone thickness in the aesthetic zone of menopausal women: A cross-sectional study.

OBJECTIVES: Dental implants are a known treatment today. It is necessary to have at least 2 mm of bone around the implant, especially in the buccal aspect of the anterior maxilla (esthetic zone). Some systemic conditions, such as menopause, can affect the body's bone mass as well as the alveolar bone. Considering that few studies have been carried out on the effect of menopause on the thickness and topography of alveolar bone, we decided to investigate the effect of menopause on buccal alveolar bone thickness in the anterior maxillary teeth in menopausal women. MATERIAL AND METHODS: In this descriptive-analytical cross-sectional study, two subgroups of menopausal women and nonmenopausal women were considered. Data were extracted from 30 patients referred to a private radiology center in Mashhad for CBCT imaging. In addition, the buccal bone thickness in the crest and middle areas of the anterior maxillary teeth was measured and the difference between the two groups was investigated. The buccal bone thickness of the aesthetic area was evaluated with CBCT Planmeca ProMax 3D Max (Planmeca) by Planmeca Romexis 5.3.4 software, with 200 µm Voxel size and Fov 90 × 60 mm. RESULTS: In this study, 30 women with a mean age of 49.75 ± 3.65 years in the nonmenopausal and menopausal groups were examined. It was found that the mean buccal bone thickness of the anterior maxilla in the nonmenopausal group (0.65 ± 0.25 mm) was higher than in the menopausal group (0.56 ± 0.20 mm), but the difference was not statistically significant (p = .2999). Only in the crestal bone of the right canine, the average bone thickness in nonmenopausal group (0.77 ± 0.33 mm) was significantly higher than the menopausal group (0.49 ± 0.22 mm) (p = .011). CONCLUSIONS: Owing to changes in the volume and thickness of alveolar bone in menopausal women, the thickness of the buccal bone in the aesthetic area decreases, but this is not statistically significant.

Importance of MMP-8 in Salivary and Gingival Crevicular Fluids of Periodontitis Patients.

BACKGROUND: Matrix metalloproteinases (MMPs) stimulate alveolar bone loss in chronic periodontitis. OBJECTIVE: To evaluate the salivary and gingival crevicular fluid (GCF) levels of MMP-8 in patients with moderate to severe chronic periodontitis. METHODS: 42 participants were divided into two groups: a case group (21 patients with generalized moderate to severe chronic periodontitis) and a control group (21 healthy periodontal subjects). GCF and saliva samples were obtained from both groups. Salivary and GCF MMP-8 levels of each subject were detected using the ELISA method. RESULTS: Mean±SD values of salivary MMP-8 levels of the control and case groups were 1.52 ± 0.65 ng/ml and 6.06 ± 1.18 ng/ml, respectively, and statistically significant difference was observed (p=0.0001). Also, mean±SD values of GCF MMP-8 levels of the control and case groups were 0.87 ± 0.26 ng/ml and 2.92 ± 0.64 ng/ml, respectively; which was statistically significant (p=0.0001). CONCLUSION: Our results demonstrate an increased concentration of salivary and GCF levels of MMP-8 in the patient group.

Comparative evaluation of IL-17 and TGF-ß expression in tissues of patients with chronic periodontitis and healthy individuals using real-time PCR.

Background: The present study aimed to determine the association between periodontal disease and the Th17/Treg balance by examining the genetic expression of IL-17 and TGF-ß, which influence incidence and suppression of inflammation. Methods: In this case-control study, samples were collected in a randomized and task-oriented order. Thirty-seven patients referred to professional periodontology clinics in Mashhad and the Periodontology Department of the Mashhad Dentistry Faculty for periodontal (case) or crown-length (control) surgery was enrolled. IL-17 and TGF-ß gene expression indices were measured in tissue samples by real-time polymerase chain reaction. Results: The IL-17 gene expression index was higher in the case group (2.68±0.91) than in the control group (1.68±0.41), but this difference was not significant. The TGF-ß gene expression index was significantly higher in the case group (54.42±7.88) than in the control group (24.12±3.38). Conclusion: L-17 and TGF-ß expression is increased in chronic periodontitis patients, but TGF-ß plays a more important role in periodontal inflammation in patients with chronic periodontitis. Further studies of the roles of Th17 and Treg cells are warranted.

Relationship between BMI ≥25 and periodontal status: A case‒ control study.

Background: Obesity is an important subject in both developed and developing countries. Obesity is a risk factor for many diseases, including cardiovascular diseases, hypertension and osteoarthritis. Periodontitis is a prevalent, chronic disease and multiple factors have been proposed to contribute to its progression. we aimed to compare the periodontal status of normalweight and obese individuals. Methods: In this study, we consecutively selected 100 patients (50 obese and overweight as the case group, based on body mass index [BMI], and 50 others with normal weight, as the control group) referred to the Periodontology Department of Mashhad Dental School. The demographic data of the participants were recorded, including age, gender, height and weight. The following periodontal parameters were assessed: periodontal pocket depth (PPD), clinical attachment level (CAL) and plaque index. Kolmogorov-Smirnov test, chi-squared test and independent t-test, as well as ANCOVA, were used to analyze data. Results: We found that the mean PPD was similar in the test and control groups (P=0.168). Moreover, CAL was not significantly different between the two groups (P=0.494). Conclusion: Our findings indicated that obesity and overweight do not seem to have an association with periodontal parameters such as periodontal pocket depth and clinical attachment loss. Further research is needed to evaluate this relationship.

Evaluation of Alveolar Crest Changes following Buccal Bone Overbuilding in Immediate Implantation.

The aim of the present study was to evaluate alveolar crest changes when using demineralized freeze-dried bone allograft (DFDBA) and resorbable membrane between flap and buccal bone in addition to filling the gap, as compared to merely filling the gap, when performing immediate implantation. In 18 patients with 24 single-root teeth, implants were placed immediately after extraction. In the test group (nine patients with 12 teeth), DFDBA and barrier membrane were placed between buccal crest and flap after implant placement. In the control group (nine patients with 12 teeth), implants were placed without buccal grafting. In addition, in both groups, if the gap width between implant and buccal crest was ≥2 mm, the gap was filled with DFDBA at the time of extraction. The height of buccal crest soft tissue and the buccolingual width of bone at 3 and 5 mm, apical to the line connecting the two cementoenamel junctions (CEJs) of adjacent teeth (CEJ line), were measured at baseline and after 4 mo. In the test group, the mean height of the buccal crest increased by 1.04 ± 0.68 mm, but in the control group, height decreased by 0.83 mm (p < 0.001). In the test group, the mean height of soft tissue increased by 0.29 mm, but in the control group, height decreased by 0.79 ± 0.72 mm (p = 0.006). The mean reduction of buccolingual width of bone in 3 and 5 mm apical to the crest in the test group was lower than that of the control group, but not significantly (p = 0.231 and 0.212, respectively). The findings of this study show that using DFDBA and membrane between buccal crest and flap in immediate implantation could increase buccal crest and soft tissue height in the midfacial region but may not significantly prevent buccolingual width reduction of bone at 3 and 5 mm from the CEJ line.

Effect of healing time on bone-implant contact of orthodontic micro-implants: a histologic study.

Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability.