Three dimensional (3D) gingival models in periodontal research: a systematic review.

The aim of this study is to systematically appraise the evidence on available full thickness 3D gingival and mucosal models (3D culture in scaffold base system) and their application in periodontal and peri-implant research. This study involved a systematic review of twenty-two studies obtained from searching from five electronic databases: MEDLINE-OVID, EMBASE, EBSCOhost, Web of Science Core Collection and LILACS, as well as a hand search of eligible articles up to September 2022. A total of 2338 studies were initially identified, after removal of duplicates (573), abstracts/title selection (1765), and full text screening (95), twenty-two studies were included, thirty-seven models were identified. Several cellular markers were reported by the studies included. The expression of keratinocytes differentiation markers (K4, K5, K10, K13, K14, K16, K17, K18, K19, involucrin, laminin5), proliferation marker (Ki67, CD90), and vimentin, Type I, II and IV collagen produced by fibroblasts were investigated in thirty models. No quantitative analyses were performed, and results of the review confirmed a substantial level of heterogeneity across experiments. In conclusion, there is currently insufficient evidence to conclude that the available 3D gingival and mucosal models can entirely recapitulate the human gingival tissue/mucosa and provide a useful research tool for periodontal and peri-implant research. This review also highlighted the lack of a standardized protocol to construct and characterize 3D gingival models. A new protocol is proposed for the characterization of in vitro gingival models for future research.

Dental nerves: a neglected mediator of pulpitis.

As one of the most densely innervated tissues, the dental pulp contains abundant nerve fibres, including sensory, sympathetic and parasympathetic nerve fibres. Studies in animal models and human patients with pulpitis have revealed distinct alterations in protein expression and histological appearance in all types of dental nerve fibres. Various molecules secreted by neurons, such as classical neurotransmitters, neuropeptides and amino acids, not only contribute to the induction, sensitization and maintenance of tooth pain, but also regulate non-neuronal cells, including fibroblasts, odontoblasts, immune cells and vascular endothelial cells. Dental nerves are particularly important for the microcirculatory and immune responses in pulpitis via their release of a variety of functional substances. Further, nerve fibres are found to be involved in dental soft and hard tissue repair. Thus, understanding how dental nerves participate in pulpitis could have important clinical ramifications for endodontic treatment. In this review, the roles of dental nerves in regulating pulpal inflammatory processes are highlighted and their implications for future research on this topic are discussed.

Chemical removal of necrotic periodontal ligament on delayed replanted teeth by sodium hypochlorite: morphological analysis and microhardness indentation test of cementum.

AIM: To compare the efficacy of sodium hypochlorite (NaOCl) used at different concentrations and working times for removing necrotic periodontal ligament (PDL) from delayed replanted teeth and to observe the effects of NaOCl on surface structure and microhardness of cementum. METHODOLOGY: A total of 88 healthy premolars with a single root extracted for orthodontic purposes were selected and kept dry at room temperature for 1 h. The teeth were divided into 11 groups: group 1 (control): roots were untreated; group 2: necrotic PDL was removed with gauze; groups 3-11: teeth were immersed in NaOCl at different concentrations (1, 2.5 and 5.25%) and for different working times (5, 10 and 15 min). The specimens in each group were inspected separately for cementum integrity and the presence of PDL remnants by histomorphometric analysis, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Another 14 healthy premolars with roots divided into two pieces were selected for Vickers microhardness indentation tests before and after NaOCl treatment. The data were analysed statistically using Wilcoxon signed-rank test of two-related samples (P = 0.05). RESULTS: In teeth treated with 1% NaOCl for 15 min or 5.25% NaOCl for 5 min, the cementum remained morphologically intact without cracks, and PDL remnants were absent. In the 1% NaOCl for 15 min group, the microstructure of cementum was arranged more regularly, as observed ×8000 magnification by SEM. Teeth in each of the other groups displayed cementum damage and/or the presence of PDL remnants. Microhardness tests revealed that treatment with 1% NaOCl for 15 min or 5.25% NaOCl for 5 min significantly decreased microhardness of root cementum (P < 0.05). CONCLUSIONS: Use of either 1% NaOCl for 15 min or 5.25% NaOCl for 5 min was effective at removing necrotic PDL from the delayed replanted teeth whilst having a minimal influence on cementum integrity. However, 1% NaOCl for 15 min was less damaging to cementum.

Effects of micro-amounts of Porphyromonas gingivalis lipopolysaccharide on rabbit inflammatory immune response and development of atherosclerosis.

BACKGROUND AND OBJECTIVE: Porphyromonas gingivalis (Pg) lipopolysaccharide is associated with the immune response and atherosclerosis. This study aimed to evaluate the effects of micro-amounts of Pg-lipopolysaccharide on rabbit inflammatory immune response and the development of atherosclerosis. MATERIAL AND METHODS: Twenty-four New Zealand white rabbits were randomly divided into four groups (n = 6). Group A was fed a regular diet and normal saline. Group B was supplied with a high-fat diet and normal saline. Group C was treated with a normal diet and Pg-lipopolysaccharide. Group D was given a high-fat diet and Pg-lipopolysaccharide. After 14 wk, the rabbits were killed to determine the changes in pathological indices. RESULTS: The serum lipid levels of groups B and D were significantly higher than that of group A (p < 0.01), and that of group C was higher (p < 0.05). Serum interleukin-6, monocyte chemoattractant protein-1 and tumor necrosis factor-α levels were significantly elevated by individual high-fat diets or Pg-lipopolysaccharide stimulation (p < 0.05). Groups A and C did not undergo evident aortic pathological damages, while foam cells appeared in the other two groups. Real-time polymerase chain reaction detection showed that toll-like receptor-2, interleukin-6, matrix metalloproteinase-9 and monocyte chemoattractant protein-1 were highly expressed in groups B and D (p < 0.05), and toll-like receptor-4, C-reactive protein and tumor necrosis factor-α levels were higher than those of group A (p < 0.05). Western blotting showed that transcription factor NF-κB p65 was expressed more highly in the three experimental groups than in group A (t = 9.26, p < 0.01). CONCLUSION: Micro-amounts of Pg-lipopolysaccharide induced the high expressions of inflammatory factors and mediated the inflammatory response. Pg-lipopolysaccharide elevated the blood lipid level less significantly than the high-fat diet did, but it may promote atherosclerosis.

Submental cutaneous sinus tract of mandibular second molar origin.

AIM: To report a case in which a submental cutaneous sinus tract resulted from apical periodontitis associated with a mandibular second molar. SUMMARY: A 53-year-old man presented with a chronic cutaneous sinus tract in the submental region, which had previously been misdiagnosed as a thyroglossal fistula. The origin of the sinus tract was shown by sinus tract angiography to be the left mandibular second molar (tooth 37), which had apical periodontitis. The sinus tract healed after extraction of the tooth and partial excision of the lesion from an extraoral approach. Histological examination confirmed that the tract was lined with granulation tissue and not with epithelial tissue. A submental sinus tract drainage pathway was observed. Prompt dental evaluation, especially of all mandibular teeth, should be considered when assessing cases of submental cutaneous sinus tracts. KEY LEARNING POINTS: An odontogenic origin should be part of the differential diagnosis for orofacial skin lesions. Cutaneous sinus tracts of mandibular molar origin are complex and thus a comprehensive examination should be stressed. It is necessary to examine all mandibular teeth in cases of odontogenic submental cutaneous sinus tracts. Sinus tract angiography can be used to identify the sinus tract pathway and to confirm the associated teeth. The treatment of an odontogenic cutaneous sinus tract requires the elimination of the source of infection.

A study of serum proteome expression in patients with severe hand-foot-mouth disease.

OBJECTIVE: Although numerous studies have been conducted on hand-foot-mouth disease (HFMD), the diagnosis of severe HFMD has not been fully clarified. Hence, it is important to further clarify the diagnosis of severe HFMD. In this study, we conducted a clinical biomarker discovery in patients with severe HFMD. PATIENTS AND METHODS: In this study, serum samples were isolated from severe HFMD, HFMD, and healthy controls. Each group consisted of 32 cases. Isobaric tagging for relative and absolute quantitation (iTRAQ) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to detect proteome expression in the serum samples. Then, candidate proteins were screened and verified by ELISA. Protein expressions were significantly different between the HFMD group, severe HFMD group, and healthy control group. RESULTS: Comparison of the proteins between the three groups showed that serum amyloid A-1 protein (P0DJ18), C-reactive protein (P02741), fibronectin (P02751), plasminogen (P00747) and apolipoprotein A (P08519) were different, so they were selected as candidate proteins. However, the results of ELISA showed that the expression levels of serum amyloid A-1 protein, C-reactive protein, fibronectin, and apolipoprotein a in the severe HFMD group were significantly different from those in the other two groups (p<0.05). CONCLUSIONS: In conclusion, the results showed that serum amyloid A-1, C-reactive protein, fibronectin, and apolipoprotein A may be potential biomarkers for clinical diagnosis of severe HFMD.

Safety and pharmacokinetics of aciclovir in women following release from a silicone elastomer vaginal ring.

OBJECTIVES: Systemic aciclovir and its prodrug valaciclovir are effective in treating and reducing recurrences of genital herpes simplex virus (HSV) and reducing transmission. Local aciclovir delivery, if it can achieve and maintain comparable intracellular genital tract levels, may be equally effective in the treatment and suppression of genital HSV. Intravaginal ring (IVR) delivery of aciclovir may provide pre-exposure prophylaxis against HSV acquisition. METHODS: Tolerability and pharmacokinetics were evaluated in six HIV-negative women with recurrent genital HSV who switched their daily oral valaciclovir suppression to an aciclovir IVR for 7 days (n = 3) or 14 days (n = 3). Blood and cervicovaginal lavage (CVL) were collected after oral and IVR dosing to measure aciclovir concentrations and genital swabs were obtained to quantify HSV shedding by PCR. RESULTS: The rings were well tolerated. Median plasma aciclovir concentrations were 110.2 ng/mL (IQR, 85.9-233.5) 12-18 h after oral valaciclovir. Little or no drug was detected in plasma following IVR dosing. Median (IQR) CVL aciclovir levels were 127.3 ng/mL (21-660.8) 2 h after oral valaciclovir, 154.4 ng/mL (60.7-327.5) 12-18 h after oral valaciclovir and 438 ng/mL (178.5-618.5) after 7 days and 393 ng/mL (31.6-1615) after 14 days of aciclovir ring use. Median CVL aciclovir levels 2 h after oral dosing were similar to levels observed 7 (P = 0.99) and 14 (P = 0.75) days after ring use. HSV DNA was not detected in genital swabs and there was no significant change in inflammatory mediators. CONCLUSIONS: This first-in-human study demonstrated that an IVR could safely deliver mucosal levels of aciclovir similar to oral valaciclovir without systemic absorption. More intensive site-specific pharmacokinetic studies are needed to determine whether higher local concentrations are needed to achieve optimal drug distribution within the genital tract.

Estimation of inhibitory quotient using a comparative equilibrium dialysis assay for prediction of viral response to hepatitis C virus inhibitors.

The relationship of inhibitory quotient (IQ) with the virologic response to specific inhibitors of human hepatitis C virus (HCV) and the best method to correct for serum protein binding in calculating IQ have not been addressed. A common method is to determine a fold shift by comparing the EC(50) values determined in cell culture in the absence and presence of human serum (fold shift in EC(50) ), but this method has a number of disadvantages. In the present study, the fold shifts in drug concentrations between 100% human plasma (HP) and cell culture medium (CCM) were directly measured using a modified comparative equilibrium dialysis (CED) assay for three HCV protease inhibitors (PIs) and for a novel HCV inhibitor GS-9132. The fold shift values in drug concentration between the HP and CCM (CED ratio) were ∼1 for SCH-503034, VX-950 and GS-9132 and 13 for BILN-2061. These values were ∼3-10-fold lower than the fold shift values calculated from the EC(50) assay for all inhibitors except BILN-2061. Using the CED values, a consistent pharmacokinetic and pharmacodynamic relationship was observed for the four HCV inhibitors analysed. Specifically, an approximate 1 log(10) reduction in HCV RNA was achieved with an IQ close to 1, while 2-3 and greater log(10) reductions in HCV RNA were achieved with IQ values of 3-5 and greater, respectively. Thus, use of CED to define IQ provides a predictive and quantitative approach for the assessment of the in vivo potency of HCV PIs and GS-9132. This method provides a framework for the evaluation of other classes of drugs that are bound by serum proteins but require the presence of serum for in vitro evaluation.

Recurrent adamantinoma of the mandible.

Adamantinoma is an extremely rare tumour originating from bone that can be divided into classical and osteofibrous dysplasia (OFD)-like adamantinoma. This low-grade malignancy almost exclusively occurs in long bones, and only few cases of mandibular adamantinoma have been reported. Here, we report the case of a 30-year-old female with a 2-year history of right mandible tenderness. Radiological examinations showed a lytic lesion involving the right mandible without a well-defined margin. Biopsy confirmed the diagnosis of adamantinoma. She underwent a segmental mandibulectomy and reconstruction with a fibula flap. The definitive diagnosis was OFD-like adamantinoma. However, the tumour recurred after 5 years. The residual mandible and fibula flap were widely involved. A total mandibulectomy was performed. Five years later, there is no evidence of recurrence or metastasis. We recommend that adamantinoma be treated by radical resection with clear margins, and long-term surveillance is necessary due to the likely high local recurrence rate and the potential for late tumour metastasis.

[Evaluation of computer-aided diagnosis system for detecting dental approximal caries lesions on periapical radiographs].

Objective: To establish and to evaluate a computer-aided system based on deep-learning for detection and diagnosis of dental approximal caries on periapical radiographs. Methods: One hundred and sixty human premolars and molars extracted for orthodontic or periodontal reasons were obtained from Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Fujian Medical University. A total of 160 periapical radiographic images were divided into a training dataset (n=80) and a test dataset (n=80). A deep-learning based computer-aided caries diagnosis system was established and trained. The performances of computer-aided diagnosis system and human observer were compared using receiver operating characteristic (ROC) curves, precision-recall (P-R) curves, the area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The AUC values of human observers and caries diagnosis system was compared by using an online statistical tool (SPSSAU 20.0). Chi-square test was used to analyze the differences between human observers and caries diagnosis system (ɑ=0.05). Results: The AUC values of human observers and caries diagnosis system were 0.729 (95%CI: 0.650-0.808) and 0.762 (95%CI: 0.685-0.839), respectively (P>0.05). No significant differences were found for the specificity, PPV and NPV between the caries diagnosis system and human observers (P all>0.05). The caries diagnosis system was significantly more sensitive in detecting dental proximal caries than human observers (P<0.05). For the diagnosis of level-1 caries (caries limited to outer 1/2 of enamel), the sensitivity of human observers and computer-aided detection system were 27% and 77%, respectively (P<0.05). Conclusions: The computer-aided diagnosis system provided similar accuracy as human observers and significantly better sensitivity than human observers, especially for shallow caries in enamel.

Solid-state interaction of stearic acid with povidone and its effect on dissolution stability of capsules.

Capsule formulations of two drugs under development showed slower dissolution upon storage; Drug A, after 2.5 weeks at 40 degrees C/23% RH and 4 weeks at 30 degrees C/60% RH, and Drug B, after 6 weeks at 50 degrees C and 40 degrees C/75% RH. The formulations of both drugs contained povidone as a binder and stearic acid as a lubricant. Replacement of stearic acid by magnesium stearate from the formulation of Drug B, which was selected for further studies, provided rapid dissolution profiles under similar storage conditions with no change occurring on storage. In order to investigate the role of stearic acid further, binary mixtures of stearic acid with the drugs and other excipients used in their respective formulations were prepared and stored at 40 degrees C/75% RH and 50 degrees C. After 1 week of storage, it was observed that povidone and stearic acid mixture formed a transparent, hard, glass-like insoluble substance. It is hypothesized that the substance formed by the interaction can reduce the porosity of the granules and thereby reduces the ingress of the dissolution medium leading to slower dissolution. The infrared (IR) spectra of the glass-like substance showed a slight broadening of the povidone carbonyl band at 1662 cm(-1). The powder X-ray diffraction of the stored mixture showed that the crystallinity of stearic acid was lost. Furthermore, repeated heating and cooling cycles of povidone and stearic acid mixtures in various proportions using differential scanning calorimetry (DSC) showed that recrystallization of stearic acid from its melt was strongly affected by the presence of increasing amounts of povidone. Based on the observed solid-state interaction, a combination of stearic and povidone should be avoided for immediate release formulations.

Substrate creep on the fatigue life of a model dental multilayer structure.

In this article, we investigated the effects of substrate creep on the fatigue life of a model dental multilayer structure, in which a top glass layer was bonded to a polycarbonate substrate through a dental adhesive. The top glass layers were ground using 120 or 600 grit sand papers before bonding to create different subsurface crack sizes and morphologies. The multilayer structures were tested under cyclic Hertzian contact loading to study crack growth and obtain fatigue life curves. The experiment results showed that the fatigue lives of the multilayer structures were impaired by increasing crack sizes in the subsurfaces. They were also significantly reduced by the substrate creep when tested at relatively low load levels, i.e. P(m) < 60 N (P(m) is the maximum magnitude of cyclic load). But at relatively high load levels, i.e. P(m) > 65 N, slow crack growth was the major failure mechanism. A modeling study was then carried out to explore the possible failure mechanisms over a range of load levels. It is found that fatigue life at relatively low load levels can be better estimated by considering the substrate creep effect.

Genome-wide association studies and meta-analysis reveal novel quantitative trait loci and pleiotropic loci for swine head-related traits.

The pig is an important domestic animal that provides a larger amount of meat and serves as a biomedical animal model for human. Head and facial features are closely linked to identity recognition in mammal communication. To uncover the genetic architecture of swine head and facial features, we constructed 5 experimental pig populations and accurately measured 10 traits related to head and facial features, for which genome-wide association studies and meta-analysis were later carried out. As a result, we identified a total of 24 loci harboring 437 SNP on 8 swine chromosomes (SSC) that surpassed suggestively significant levels, of which 17 loci on 6 chromosomes exceeded the 5% genome-wide significance thresholds. To our knowledge, this is the first report of QTL for the distance from the low corner of the eye to the snout end (DES) and to the mouth corner (DEM), the size of extra mouth cleft (EMC), lip thickness, head length, and tongue weight and length in pigs. Notably, 3 pleiotropic loci were detected, including the loci at 298.1 Mb on SSC1 for head length and DES, at about 80.0 Mb on SSC4 for head weight, tongue weight and length, and at 34.8 Mb on SSC7 for head weight, EMC, and lip thickness. Several positional candidate genes at the identified loci might play roles in craniofacial development or have been implicated in syndromes affecting human head and facial features, including glutamate metabotropic receptor 4 (), high mobility group AT-hook 1 (), high mobility group AT-hook 2 (), serum/glucocorticoid regulated kinase family member 3 (), pleiomorphic adenoma gene 1 (), proto-oncogene serine/threonine-protein kinase mos () and DENN (differentially expressed in normal and neoplastic cells) domain containing 1A (). These findings will contribute to further detection of the causal mutations underlying these QTL for head and facial features in pigs and provide insights into the genetic basis of head and facial characteristics in human or other mammals.

Interfacial failure of a dental cement composite bonded to glass substrates.

OBJECTIVES: To measure the interfacial fracture toughness and investigate failure mechanisms of dental cements bound to soda-lime glasses elastically equivalent to dental ceramics, as loading angle changes from 0 to 20 degrees . METHODS: Two half-circle glass discs received surface treatment were bound using dental cement (3M RelyXTM ARC BLBL) to make Brazil-nut sandwich specimens for interfacial toughness testing. Before bonding the two half-circle glass disks, 8% hydrofluoric acid (HF) was applied on the surfaces to bond for 2 min, washed thoroughly for 1 min under tap water and air dried. The surfaces were further treated using silane primer Monobond-s (Vivadent, Liechtenstein) for 60s and air dried. Interfacial toughness as a function of mode mixity was measured using an Instron testing machine by changing loading angels from 0 to 20 degrees . The interfacial fracture surfaces were examined using SEM and EDX to determine the failure modes when loading angles change. RESULTS: Interfacial toughness increases from approximately 1 to 8 J/m/m when loading angle increases from 0 to approximately 20 degrees . Increasing deformation and fracture in dental cement occur when loading angle increases. SIGNIFICANCES: Increasing interfacial toughness can be attributed to more deformation and fracture of dental cement when loading angle increases. Brazil-nut sandwich samples are shown to provide a promising alternative method to evaluate bond strength and interfacial failure for dental restoration. Research was supported by NIH (NYU/PHS No. F5262-07).

Inhibitory effect of green tea on the growth of established skin papillomas in mice.

In 10 separate experiments, mice with established chemically induced or UV light-induced skin papillomas were treated continuously with green tea in the drinking water or with i.p. injections of a green tea polyphenol fraction or (-)-epigallocatechin gallate three times a week for 4-10 weeks. Partial tumor regression or > 90% inhibition of tumor growth, as measured by changes in tumor volume per mouse, was observed in 5 experiments, and marked inhibition of tumor growth (46-89%) was observed in 5 additional experiments. Treatment of the mice with green tea or green tea constituents had an inhibitory effect on body weight increases in several but not all of the studies. Examination of the data from all ten experiments revealed that complete tumor regression occurred in 14 of 346 papilloma-bearing mice (4%) that were treated with green tea in the drinking water or with i.p. injections of green tea constituents, whereas none of the 220 papilloma-bearing control mice treated with only vehicle exhibited complete tumor regression. These observations indicate that oral administration of green tea, i.p. administration of a green tea polyphenol fraction, or i.p. administration of (-)-epigallocatechin gallate inhibited the growth and/or caused the regression of established experimentally induced skin papillomas.

Effects of tea, decaffeinated tea, and caffeine on UVB light-induced complete carcinogenesis in SKH-1 mice: demonstration of caffeine as a biologically important constituent of tea.

Oral administration of green or black tea inhibited UVB light-induced complete carcinogenesis in the skin of SKH-1 mice. Green tea was a more effective inhibitor than black tea. Oral administration of decaffeinated green or black tea resulted in substantially less inhibitory activity than did administration of the regular teas, and in one experiment, administration of a high-dose level of the decaffeinated teas enhanced the tumorigenic effect of UVB. Oral administration of caffeine alone had a substantial inhibitory effect on UVB-induced carcinogenesis, and adding caffeine to the decaffeinated teas restored the inhibitory effects of these teas on UVB-induced carcinogenesis. In additional studies, topical application of a green tea polyphenol fraction after each UVB application inhibited UVB-induced tumorigenesis. The results indicate that caffeine contributes in an important way to the inhibitory effects of green and black tea on UVB-induced complete carcinogenesis.

Biodegradable interstitial release polymer loading a novel small molecule targeting Axl receptor tyrosine kinase and reducing brain tumour migration and invasion.

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumour. The neoplasms are difficult to resect entirely because of their highly infiltration property and leading to the tumour edge is unclear. Gliadel wafer has been used as an intracerebral drug delivery system to eliminate the residual tumour. However, because of its local low concentration and short diffusion distance, patient survival improves non-significantly. Axl is an essential regulator in cancer metastasis and patient survival. In this study, we developed a controlled-release polyanhydride polymer loading a novel small molecule, n-butylidenephthalide (BP), which is not only increasing local drug concentration and extending its diffusion distance but also reducing tumour invasion, mediated by reducing Axl expression. First, we determined that BP inhibited the expression of Axl in a dose- and time-dependent manner and reduced the migratory and invasive capabilities of GBM cells. In addition, BP downregulated matrix metalloproteinase activity, which is involved in cancer cell invasion. Furthermore, we demonstrated that BP regulated Axl via the extracellular signal-regulated kinases pathway. Epithelial-to-mesenchymal transition (EMT) is related to epithelial cells in the invasive migratory mesenchymal cells that underlie cancer progression; we demonstrated that BP reduced the expression of EMT-related genes. Furthermore, we used the overexpression of Axl in GBM cells to prove that Axl is a crucial target in the inhibition of GBM EMT, migration and invasion. In an in vivo study, we demonstrated that BP inhibited tumour growth and suppressed Axl expression in a dose-dependent manner according to a subcutaneous tumour model. Most importantly, in an intracranial tumour model with BP wafer in situ treatment, we demonstrated that the BP wafer not only significantly increased the survival rate but also decreased Axl expression, and inhibited tumour invasion. These results contribute to the development of a BP wafer for a novel therapeutic strategy for treating GBM invasion and increasing survival in clinical subjects.