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Objective and Background: This research aimed to examine the role of C‐X‐C motif chemokine ligand 5 (CXCL5) and C‐X‐C motif chemokine ligand 8 (CXCL8; also known as IL‐8) in neutrophilic inflammation triggered by peri‐implantitis and to shed light on the underlying mechanisms that link them to the development of this condition. Materials: This study included 40 patients who visited the Department of Periodontology at Kyungpook University Dental Hospital. They were divided into two groups based on their condition: healthy implant (HI) group (n = 20) and peri‐implantitis (PI) group (n = 20). Biopsy samples of PI tissue were collected from the patients under local anesthesia. HI tissue was obtained using the same method during the second implant surgery. To construct libraries for control and test RNAs, the QuantSeq 3′ mRNA‐Seq Library Prep Kit (Lexogen, Inc., Austria) was used according to the manufacturer's instructions. Samples were pooled based on representative cytokines obtained from RNA sequencing results and subjected to Reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR). Hematoxylin and eosin staining, and immunohistochemistry (IHC) analysis were performed to visually assess expression levels and analyze tissue histology. Student's t‐test was employed to conduct statistical analyses. Results: Initially, heatmaps were used to examine gene expression variations between the HI and PI groups based on the results of RNA sequencing. Notably, among various cytokines, CXCL5 and CXCL8 had the highest expression levels in the PI group compared with the HI group, and they are known to be associated with inflammatory responses. In the gingival tissues, the expression of genes encoding cytokines such as interleukin (IL)‐1β, tumor necrosis factor‐alpha (TNF)‐α, interleukin (IL)‐6, and CXCL5/CXCL8 was assessed via RT‐qPCR. The mRNA expression level of CXCL5/CXCL8 significantly increased in the PI group compared with the HI group (p <.045). Contrarily, the mRNA expression level of interleukin 36 receptor antagonist (IL36RN) significantly decreased (p <.008). IHC enabled examination of the distribution and intensity of CXCL5/CXCL8 protein expression within the tissue samples. Specifically, increased levels of CXCL5/CXCL8 promote inflammatory responses, cellular proliferation, migration, and invasion within the peri‐implant tissues. These effects are mediated through the activation of the PI3K/Akt/NF‐κB signaling pathway. Conclusions: This study found that the PI sites had higher gene expression level of CXCL8/CXCL5 in the soft tissue than HI sites, which could help achieve more accurate diagnosis and treatment planning. [ABSTRACT FROM AUTHOR]

Background and Objectives: The current study aimed to compare the extent of bone growth achieved after guided tissue regeneration (GTR) based on the location and nature of the initial periodontal lesion. Materials and Methods: The study sample included 80 patients who underwent GTR at Kyungpook National University Dental Hospital since 2012 and were radiologically followed up for at least 2 years after treatment. The patients were divided into four groups based on the location (maxilla and mandible) and nature (furcation involvement and intrabony defects) of the lesion. Differences in bone levels before and after treatment were analyzed. Additionally, a comparison of outcomes based on the type of bone graft material used was conducted. Statistical analysis included a comparison of groups using a t-test, assuming equal variance. Results: The proportion of bone growth observed in the maxillary furcation, mandibular furcation, maxillary intrabony, and mandibular intrabony lesions was 26%, 22%, 31%, and 34%, respectively. No statistically significant differences in the amount of bone fill were observed between the groups. However, a significant positive correlation was found between the initial depth of the bone defect and the amount of bone fill observed after treatment. Conclusions: Contrary to previous evidence, the current study observed no significant differences in the amount of bone fill after GTR based on the location and nature of the lesion. Furthermore, the amount of bone regenerated was directly proportional to the initial depth of the alveolar bone defect. [ABSTRACT FROM AUTHOR]

Lipid biosynthesis is recently studied its functions in a range of cellular physiology including differentiation and regeneration. However, it still remains to be elucidated in its precise function. To reveal this, we evaluated the roles of lysophosphatidic acid (LPA) signaling in alveolar bone formation using the LPA type 2 receptor (LPAR2) antagonist AMG‐35 (Amgen Compound 35) using tooth loss without periodontal disease model which would be caused by trauma and usually requires a dental implant to restore masticatory function. In this study, in vitro cell culture experiments in osteoblasts and periodontal ligament fibroblasts revealed cell type‐specific responses, with AMG‐35 modulating osteogenic differentiation in osteoblasts in vitro. To confirm the in vivo results, we employed a mouse model of tooth loss without periodontal disease. Five to 10 days after tooth extraction, AMG‐35 facilitated bone formation in the tooth root socket as measured by immunohistochemistry for differentiation markers KI67, Osteocalcin, Periostin, RUNX2, transforming growth factor beta 1 (TGF‐β1) and SMAD2/3. The increased expression and the localization of these proteins suggest that AMG‐35 elicits osteoblast differentiation through TGF‐β1 and SMAD2/3 signaling. These results indicate that LPAR2/TGF‐β1/SMAD2/3 represents a new signaling pathway in alveolar bone formation and that local application of AMG‐35 in traumatic tooth loss can be used to facilitate bone regeneration and healing for further clinical treatment. [ABSTRACT FROM AUTHOR]

Background and Objectives: The purpose of this study is to assess the long-term maintenance of each approach of sinus elevation, the crestal approach and lateral approach, by comparing the radiographic results of each technique. Materials and Methods: In total, 103 patients who had undergone an implant procedure with either the crestal approach or lateral approach method applied to their maxillary molar edentulous area were included. Using orthopantomographs, the radiographic changes were consistently evaluated over 3 years after the procedure (immediately after procedure and 1 year, 2 years and 3 years after implant placement) Results: The radiographic evaluation after 3 years of implantation with sinus elevation showed a significant amount of bone formation (8.07 mm for crestal approach and 12.00 mm for lateral approach method). The largest amount of grafted height loss occurred during the 1 year, but the resorption was minimal (0.98 mm for crestal approach and 0.95 mm for lateral approach method) over the entire 3 years. Conclusions: Although the lateral approach showed more bone growth, the amount of bone resorption was similar to that of the crestal approach. Both methods showed the highest amount of bone resorption in the first year, and the amount of change thereafter was insignificant. It is judged that both methods can be used according to the situation to help implant placement. [ABSTRACT FROM AUTHOR]