Periodontitis is a chronic inflammatory disease caused by dysbiosis of the periodontal microbiome, threatening both oral and systemic health. Current prevention and treatment strategies for periodontitis mainly rely on mechanical therapy, with antibiotics used as supplements. However, limitations of mechanical therapy and increasing antibiotic resistance have prompted the exploration of new adjunctive strategies. Probiotic therapy, particularly Lacticaseibacillus rhamnosus (L. rhamnosus), formerly known as Lactobacillus rhamnosus, has emerged as a promising approach due to its ability to modulate periodontal microecology. L. rhamnosus exerts therapeutic effects by inhibiting pathogens, modulating immune responses, and promoting tissue repair. L. rhamnosus has been applied in various forms for the adjuvant treatment of periodontitis and numerous clinical trials have confirmed its safety and effectiveness, indicating broad potential for application. Nevertheless, current clinical studies still face challenges such as unclear strain-specific effects and a lack of standardized administration protocols. Future research should investigate the mechanisms of different strains and evaluate targeted interventions in diverse patient populations to advance the clinical use of probiotic therapies.

Addressing the problems of low footage and premature failure of existing PDC bits in high-temperature geothermal wells, this study investigates the limestone fragmentation characteristics of PDC cutters under high-temperature conditions. Adopting a combined approach of experimental testing, numerical simulation, and full-scale drilling verification, the effects of key parameters-temperature, rake angle, and cutting depth-on rock-breaking characteristics. The findings reveal that: (1)The mechanical parameters of limestone, such as compressive strength and shear strength, first increase and then decrease with rising temperature, reaching a peak at 250°C, where rock-breaking difficulty is the highest; (2)Single-cutter cutting tests indicate that 350°C is the optimal rock-breaking temperature, and the specific energy of fragmentation is the lowest with the highest rock-breaking efficiency when the rake angle is 15° and the cutting depth is 2mm; (3) Simulations demonstrated that both the temperature and contact stress on the cutter face increase with penetration depth but decrease with rake angle; (4)A new Φ118mm drill bit is designed based on the research. Experimental results show that the bit operates well in high-temperature environments, with a torque increase of 5.8% and a rate of penetration improvement of 31.9% compared to conventional PDC bits. This study clarifies the optimal rock-breaking parameter combination of PDC cutters under high-temperature conditions, providing key technical support for the cutter profile optimization, structural design, and drilling parameter regulation of PDC bits for high-temperature geothermal wells.

The range of possible inflammatory changes in the oral cavity and in the maxillary and mandibular bones may present with diverse patterns and characteristics in both clinical and radiological evaluation. In most cases, a standard radiological examination, such as dental panoramic radiograph (DPR), has significant limitations in assessing early or complex bone changes associated with chronic bone inflammation. Advanced imaging with multidetector computed tomography or cone-beam computed tomography (MDCT or CBCT) can improve lesion characterization and surgical planning when a detailed evaluation of tooth-bearing structures, tooth apices, cortical plates, and cancellous bone is required. Such imaging allows more detailed assessment of alterations in medullary bone morphology and architecture, as well as identification of possible periosteal reactions adjacent to chronic bone inflammation. Osteomyelitis of the jaws comprises a heterogeneous group of inflammatory bone disorders characterized by variable clinical presentations and a broad spectrum of radiological appearances. Depending on disease chronicity, host factors, and microbial burden, mandibular osteomyelitis may mimic odontogenic tumors, fibro-osseous lesions, or malignant bone pathologies. Quite often, dental treatment affects bone status and condition, leading to unwanted events such as bone inflammation. Imaging plays a central role in diagnosis; however, radiographic findings are often nonspecific, particularly in early or chronic stages. Each case of osteomyelitis underscores the importance of correlating imaging findings with clinical history and highlights the role of repeated imaging in distinguishing inflammatory bone disease from aggressive jaw lesions. This study aims to characterize diverse patterns of chronic mandibular osteomyelitis associated with various prior treatment modalities using CBCT. By presenting a series of illustrative cases from heterogeneous clinical settings, the authors highlight the nonspecific radiographic features and diagnostic challenges inherent in chronic bone inflammation. The focus remains on the interpretation of complex imaging findings rather than a comparative analysis of technical protocols.