Digital dentistry has witnessed significant advancements in recent years, driven by extensive research following the introduction of cutting-edge technologies such as CAD/CAM and 3D oral scanners. Until now, 2D images obtained via x-ray or CT scans were critical to detect anomalies and for decision-making. This review describes the main principles and applications of supervised, unsupervised, and reinforcement learning in medical applications. In this context, we present a diverse range of artificial intelligence networks with potential applications in dentistry, accompanied by existing results in the field.

Peri-implantitis is a disease affecting the tissue surrounding dental implants, destroying both soft and hard tissues. A total of 2,015 studies were collected by searching items in the National Library of Medicine, including keywords, such as “peri-implantitis,” “microbiota,” and “microbiome.” Of them, 62 studies were screened and considered eligible for analysis. Only 16 studies qualified all criteria mentioned here: “Using PCR methods for microorganism detection,” “Suggesting quantified results,” “Stating obvious clinical diagnosis criteria (“Bleeding on probing,” “Probing pocket depth,” “Suppuration,” and “Radiographic bone loss”).” Only 8 studies were included in the meta-analysis because the others had special issues. Porphyromonas gingivalis , Tannerella forsythia , Treponema denticola , Aggregatibacter actinomycetemcomitans, Prevotella intermedia , and Epstein-Barr virus were the microbiological subjects of analysis. The odds ratio (OR) between the healthy implants and peri-implantitis were calculated for each microorganism to compare two groups, and the forest plots were suggested as the visual materials. P. gingivalis (1.392 < OR < 2.841), T. forsythia (1.345 < OR < 3.221), T. denticola (2.180 < OR < 5.150), A. actinomycetemcomitans (1.975 < OR < 6.456), P. intermedia (1.245 < OR < 3.612), and Epstein-Barr virus (1.995 < OR < 9.383). The species showed that their 95% confidence interval of odds ratio was higher than 1, indicating that they were detected more frequently in periimplantitis than in healthy implants. Meanwhile, other species, such as Fusobacterium nucleatum and Staphylococcus aureus, were not included in the meta-analysis because the number of studies was insufficient.

The rapid detection of bacteria in the oral cavity, its species identification, and bacterial count determination are important to diagnose oral diseases caused by pathogenic bacteria. The existing clinical microbial diagnosis methods are time-consuming as they involve observing patients’ samples under a microscope or culturing and confirming bacteria using polymerase chain reaction (PCR) kits, making the process complex. Therefore, it is required to analyze the development status of substances and systems that can rapidly detect and analyze pathogenic microorganisms in the oral cavity. With research advancements, a close relationship between oral and systemic diseases has been identified, making it crucial to identify the changes in the oral cavity bacterial composition. Additionally, an early and accurate diagnosis is essential for better prognosis in periodontal disease. However, most periodontal diseasecausing pathogens are anaerobic bacteria, which are difficult to identify using conventional bacterial culture methods. Further, the existing PCR method takes a long time to detect and involves complicated stages. Therefore, to address these challenges, the concept of point-of-care (PoC) has emerged, leading to the study and implementation of various chair-side test methods. This study aims to investigate the different PoC diagnostic methods introduced thus far for identifying pathogenic microorganisms in the oral cavity. These are classified into three categories: 1) microbiological tests, 2) microchemical tests, and 3) genetic tests. The microbiological tests are used to determine the presence or absence of representative causative bacteria of periodontal diseases, such as A. actinomycetemcomitans , P. gingivalis , P. intermedia , and T. denticola . However, the quantitative analysis remains impossible, and detecting pathogens other than the specific ones is challenging. The microchemical tests determine the activity of inflammation or disease by measuring the levels of biomarkers present in the oral cavity. Although this diagnostic method is based on increase in the specific biomarkers proportional to inflammation or disease progression in the oral cavity, its commercialization is limited due to low sensitivity and specificity. The genetic tests are based on the concept that differences in disease vulnerability and treatment response are caused by the patient’s DNA predisposition. Specifically, the IL-1 gene is used in such tests. PoC diagnostic methods developed to date serve as supplementary diagnostic methods and tools for patient education, in addition to existing diagnostic methods, although they have limitations in diagnosing oral diseases alone. Research on various PoC test methods that can analyze and manage the oral cavity bacterial composition is expected to become more active, aligning with the shift from treatmentoriented to prevention-oriented approaches in healthcare.

천연물 중 시판되지 않고 대부분 버려지는 흑호두(Juglans nigra) 과피를 추출하여 화장품 적용 가능성과 생리 활성 및 효능을 조사하였다. 흑호두 과피 열수 추출물의 DPPH 라디칼 소거능은 300 μg/mL에서 76.06%였으며 ABTS 라디칼 소거 활성은 1000 μg/mL에서 61%로 우수한 항산화 활성을 나타냈다. 흑호두 과피 추출물을 피부 각질 세포인 HaCaT 세포에 적용했을 때 250 μg/mL에서 92.6%로 세포 생존율에 미치는 영향이 현저히 낮았고 500 μg/mL 농도에서 67.35%의 nitric oxide(NO) 생성이 억제 되었으며 100 μg/mL 농도에서 비타민 C보다 31배 더 높은 Hyaluronidase 억제 효과를 나타냈다. 결론적으로 흑호두 과피 추출물은 코스메슈티컬 응용 및 식품, 향료, 헬스 케어, 제약 등 다양한 산업에서 고부가 가치 천연 소재로 활용 가능성을 시사하고 있다.

Xylitol is a sugar alcohol with a variety of functions including bactericidal and anticariogenic effects. However, the cellular mechanisms underlying the role of xylitol in bone metabolism are not yet clarified. In our present study, we exploited the physiological role of xylitol on osteoclast dif-ferentiation in a co-culture system of osteoblastic and RAW 264.7 cells. Xylitol treatment of these co-cultures reduced the number of tartrate-resistant acid phosphatase (TRAP)- positive multinucleated cells induced by 10 nM 1α,25(OH)2 D3 in a dose‐dependent manner. A cell viability test revea-led no marked cellular damage by up to 100 mM of xylitol. Exposure of osteoblastic cells to xylitol decreased RANKL, but not OPG, mRNA expression in the presence of 10-8 M 1α,25(OH)2D3 in a dose‐dependent manner. Furthermore, bone resorption activity, assessed on bone slices in the co- culture system, was found to be dramatically decreased with increasing xylitol concentrations. RANKL and OPG proteins were assayed by ELISA and the soluble RANKL (sRANKL) concentration was decreased with an increased xylitol con-centration. In contrast, OPG was unaltered by any xylitol con-centration in this assay. These results indicate that xylitol inhibits 1α,25(OH)2D3-induced osteoclastogenesis by reducing the sRANKL/OPG expression ratio in osteoblastic cells.

Bone remodeling is a process controlled by the action of two major bone cells; the bone forming osteoblast and the bone resorbing osteoclast. In the process of osteoclastogenesis, stromal cells and osteoblast produce RANKL, OPG, and M-CSF, which in turn regulate the osteoclastogenesis. During the bone resorption by activated osteoclasts, extracellular Ca²+/PO₄²- concentration and degraded organic materials goes up, providing the hypertonic microenvironment. In this study, we tested the effects of hypertonicity due to the degraded organic materials on osteoclastogenesis in co-culture system. It was examined the cellular response of osteoblastic cell in terms of osteoclastogenesis by applying the sucrose, and mannitol, as a substitute of degraded organic materials to co-culture system. Apart from the sucrose, mannitol, and NaCl was tested to be compared to the effect of organic osmotic particles. The addition of sucrose and mannitol (25, 50, 100, 150, or 200 mM) to co-culture medium inhibited the number of tartrate-resistant acid phosphatase (TRAP) positive multinucleated cells induced by 10 nM (). However, NaCl did exert harmful effect upon the cells in this co-culture system, which is attributed to DNA damage in high concentration of NaCl. To further investigate the mechanism by which hypertonicity inhibits -induced osteoclastogenesis, the mRNA expressions of receptor activator of nuclear factor (NF)-kB ligand (RANKL) and osteoprotegerin (OPG) were monitored by RT-PCR. In the presence of sucrose (50 mM), RANKL mRNA expression was decreased in a dose-dependent manner, while the change in OPG and M-CSF mRNA were not occurred in significantly. The RANKL mRNA expression was inhibited for 48 hours in the presence of sucrose (50 mM), but such a decrement recovered after 72 hours. However, there were no considerable changes in the expression of OPG and M-CSF mRNA. Conclusively, these findings strongly suggest that hypertonic stress down-regulates -induced osteoclastogenesis via RANKL signal pathway in osteoblastic cell, and may playa pivotal role as a regulator that modulates osteoclastogenesis.