In this review, we analyze the local application of PTH and its facilitation of jaw regeneration, with the goal of providing a foundation for future research and clinical application of PTH.
Research into periodontal bone regeneration through tissue engineering has significantly intensified in recent years. Usually, the periodontal tissue engineering approach leverages stem cells originating from healthy dental tissues, but their procurement is subject to the demanding conditions imposed by the need for tooth extraction and the constraint on the number of suitable sources. Inflamed pulp, periapical tissues, and periodontal tissues are the chief contributors of stem cells in the inflamed dental tissues. Stem cells are prevalent in inflamed dental tissues, maintaining the defining characteristics of stem cells, in comparison to those from healthy tissues, and potentially serving as a promising resource for periodontal bone regeneration. This review encapsulates the present and future applications of stem cells in repairing inflamed dental tissue and stimulating periodontal bone regeneration, subsequently exploring their potential as seed cells to offer guidance for future research and clinical use of these cells in inflamed dental tissues.
A substantial health concern in today's society is obesity, which frequently leads to a chronic state of low-grade inflammation, a known trigger for chronic diseases like hypertension, type 2 diabetes, and non-alcoholic fatty liver disease. As a persistent oral infection, periodontitis is frequently marked by gingival inflammation, the development of periodontal pockets, the reduction of alveolar bone, and the movement of teeth. The crucial goal in addressing periodontitis is to regenerate periodontal tissue within the affected region of the defect. A major contributor to periodontitis, obesity can affect periodontal tissue regeneration by modifying the inflammatory microenvironment within the periodontium in a multitude of ways. This paper will scrutinize the association between obesity and periodontal tissue regeneration, including the mechanisms underlying the effects of obesity on periodontal tissue regeneration, and discussing regenerative therapeutic strategies. The goal is to offer fresh perspectives on periodontal tissue regeneration in obesity.
Investigating the effects of polyetheretherketone, zirconium dioxide, and titanium abutment materials on the expression of hemidesmosome-related genes and proteins in human gingival epithelial cells to isolate materials that readily allow for epithelial adhesion. Forty-eight specimens, each crafted from one of three distinct materials—polyetheretherketone, zirconium oxide, and pure titanium—were prepared. Each specimen group's surface morphology was examined via scanning electron microscopy; surface roughness was quantitatively assessed by a white light interferometer; and the contact angle was determined using an optical contact angle measuring device. Human gingival epithelial cell adhesion to each specimen group's surface was scrutinized using scanning electron microscopy. A cell counting kit assessed the proliferative potential of human gingival epithelial cells on each specimen set. Gene and protein expression levels associated with human gingival epithelial cell adhesion on the surfaces of each specimen group were determined using real-time fluorescence quantitative PCR and Western blotting, respectively. A consistent flatness and smoothness characterized the surface morphology of the three specimen groups. The mean roughness (Ra) measurements for polyetheretherketone, zirconia, and pure titanium samples demonstrated substantial differences: 9,563,206 nm, 3,793,356 nm, and 1,342,462 nm, respectively (F=36816, P<0.05). The polyetheretherketone group exhibited significantly higher cell proliferation rates than the zirconia and pure titanium groups at both 5 and 7 days of culture (P < 0.05). Compared to the zirconium oxide and pure titanium groups, the polyetheretheretherketone group demonstrated significantly greater mRNA and protein expression levels for laminin 3, integrin 4, and collagen at both 3 and 7 days of incubation (P < 0.05). Among the abutment materials evaluated, polyetheretherketone demonstrates the most favorable conditions for hemidesmosome adhesion in human gingival epithelial cells, surpassing zirconium dioxide and pure titanium.
Employing a 3D finite element analysis approach, this study investigates the impact of two-step and en-masse retraction strategies on the movement of anterior teeth and posterior anchorage support during clear aligner treatment. Medicine history A finite element model simulating clear aligner treatment for a maxillary first premolar extraction was derived from cone-beam CT scans of a 24-year-old male patient with normal occlusion who was treated at the Department of Oral Surgery, Shanghai Jiao Tong University School of Medicine's Ninth People's Hospital, for an impacted mandibular third molar in June 2022. We investigated the initial displacement of teeth in five anterior retraction protocols, namely two-step with canine retraction, two-step with incisor bodily retraction, two-step with incisor retraction-overtreatment, en-masse bodily retraction, and en-masse retraction-overtreatment. Results of the two-step canine retraction procedure indicated distal tipping of the canine and labial tipping of the central (018) and lateral (013) incisors. A mesial inclination of the canine tooth was observed subsequent to the two-step procedure including incisor retraction. Uncontrolled lingual tipping was observed in the central incisor (029) and lateral incisor (032) during the two-step bodily retraction protocol. compound library inhibitor Using the two-step incisor retraction and overtreatment approach, the movement trajectory of the incisors remained unchanged; however, their inclinations were reduced to 21 degrees and 18 degrees. The collective retraction of teeth led to the canine tooth's distal tipping. Within the en-masse bodily retraction protocol, the central incisor (019) and lateral incisor (027) experienced uncontrolled lingual tipping. The protocol of en-masse retraction-overtreatment caused the central incisor to show controlled lingual tipping (002) and the lateral incisor to display palatal root movement (003 labial inclination). Mesial tipping affected the posterior teeth in each of the five tested protocols. The application of en-masse incisor retraction, further augmented by overtreatment, yielded beneficial results in regulating incisor torque within clear aligner therapy.
The objective is to delve into the impact of the kynurenine pathway on osteogenic differentiation within periodontal ligament stem cells (PDLSCs). Between June and October 2022, unstimulated saliva samples were gathered from 19 patients with periodontitis (periodontitis group) and 19 periodontally healthy individuals (health group) at the Nanjing Stomatological Hospital, Affiliated Hospital of Nanjing University's Medical School. To determine the kynurenine and its metabolite levels, saliva samples were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry. Further immunohistochemical examination was undertaken to pinpoint the expression of indoleamine 2,3-dioxygenase (IDO) and aryl hydrocarbon receptor (AhR) in gingival tissues. Extracted teeth for orthodontic treatment at Nanjing Stomatological Hospital, Nanjing University Medical School's Affiliated Hospital, served as the source of the PDLSCs used in this investigation, the collection period spanning from July to November 2022. Utilizing an in vitro approach, cells were subjected to incubation conditions, either supplemented with (kynurenine group) kynurenine or lacking it (control group), for subsequent experimental procedures. A week later, investigations into alkaline phosphatase (ALP) activity and its staining were performed. Quantitative real-time PCR (qPCR) analysis, utilizing fluorescence detection, was used to assess the expression levels of osteogenic-related genes, namely alkaline phosphatase (ALP), osteocalcin (OCN), runt-related transcription factor 2 (RUNX2), collagen type-I (COL-I), and also kynurenine pathway genes such as aryl hydrocarbon receptor (AhR) and cytochrome P450 enzymes (CYP1A1 and CYP1B1). Western blotting, used on day 10 to quantify RUNX2, osteopontin (OPN), and AhR protein expression, was followed by alizarin red staining on day 21 to examine mineral nodule formation in control and kynurenine groups. Compared to the health group, the periodontitis group displayed significantly higher salivary concentrations of kynurenine ([826 (0, 1960) nmol/L]) and kynurenic acid ([114 (334, 1352) nmol/L]). The healthy group's levels were [075 (0, 425) nmol/L] and [192 (134, 388) nmol/L], respectively. Statistical significance was observed (Z = -284, P = 0.0004; Z = -361, P < 0.0001). Intestinal parasitic infection The expression of IDO (1833222) and AhR (44141363) was found to be markedly elevated in the gingival tissues of periodontitis patients, exhibiting significantly higher levels than those observed in the health group (1221287, 1539514), as supported by t-tests (t=338, P=0015; t=342, P=0027). The kynurenine group (29190235) displayed a considerably lower ALP activity in PDLSCs in vitro compared to the control group (329301929) based on a statistically significant t-test result (t=334, P=0.0029). The kynurenine group (043012, 078009, 066010) displayed a reduction in mRNA expression for ALP, OCN, and RUNX2, compared to the control group (102022, 100011, 100001), with significant statistical differences (t=471, P=0.0003; t=323, P=0.0018; t=673, P<0.0001). In contrast, the kynurenine group (143007, 165010) showed an increase in the mRNA levels of AhR and CYP1A1 compared with the control group (101012, 101014), as determined by the statistical tests (t=523, P=0.0006; t=659, P<0.0001). Comparative analysis of COL- and CYP1B1 mRNA levels revealed no noteworthy difference among the groups. Relative to the control group (100000, 100000, 100000), the kynurenine group displayed a decrease in the protein levels of OPN, RUNX2 (082005, 087003), and an increase in AhR (124014). These changes are statistically significant (t=679, P=0003; t=795, P=0001; t=304, P=0039). Periodontitis patients exhibit an overstimulated kynurenine pathway, resulting in increased AhR expression and hampered osteogenic differentiation of periodontal ligament stem cells.