Efficacy of polyacrylate silver salt/polyvinylpyrrolidone-based liquid oral gel in management of concurrence chemoradiotherapy-induced oral mucositis.

BACKGROUND/PURPOSE: Acute oral mucositis (OM) is a painful complication of concurrent chemoradiotherapy (CCRT). This severe adverse symptom may impact on patient's quality of life, lead to malnutrition. Thus, finding more effective methods in OM management is very important. The purpose of this study is to evaluate the efficacy of polyacrylate silver salt/Polyvinylpyrrolidone-based liquid oral gel (named as polyacrylate silver salt oral gel) in improving the symptomatic relief of CCRT-induced oral mucositis and oral dysfunction in neck and head cancer patients. METHODS: In this study, 24 oral cancer patients underwent CCRT and having OM grade 2 or higher were randomly assigned into the test group and the control group. Both groups followed Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) clinical practice guidelines for the management of mucositis, but adding rinsing with 15 g oral gel right after oral hygiene treaded the test group. Clinical OM and oral function were assessed weekly for 4 consecutive weeks till 5-10 days after the completion of radiotherapy. For evaluation, Common Terminology Criteria for Adverse Events (CTCAE) v3.0 was used for collecting the data of OM grade. RESULTS: The results showed that polyacrylate silver salt oral gel had better effect for relieving the oral mucositis. There were statistically significant differences in OM grades (1.59 vs. 2.8, p < 0.0001) between the test group and the control group. CONCLUSION: Our clinical studies demonstrated that polyacrylate silver salt oral gel is an effective interventional option in terms of rapid mucositis healing.

Application of a commercial single-port device for robotic single-incision distal pancreatectomy: initial experience.

PURPOSE: Laparoscopic distal pancreatectomy has proven to be feasible and safe. Moreover, robotic surgery provides unique advantages for pancreatic procedures, although single-incision robotic pancreatic surgery is rarely discussed. We applied the single-port modified platform to accomplish robotic distal pancreatectomy in a series of patients. METHODS: The subjects of this study were ten patients who underwent robotic distal pancreatectomy in our hospital between July 1, 2015 and Dec 31, 2016. All patients were placed supine in the reverse Trendelenburg position with the legs abducted. Surgery was performed via a trans-umbilical 5.0-cm incision, using a modified single-port platform (LAGIPORT®) combined with the da Vinci Si Surgical System. The three arms and scope (30-degree up) were inserted through the LAGIPORT® and positioned in a triangle. Endoscopic ultrasound was used to localize the tumor and plan the resection margin. We recorded the surgical time, operation time, blood loss, postoperative pain score, hospital stay, and complications. RESULTS: The surgical time was 236 ± 32 min, the operation time was 172 ± 30 min, and the blood loss was 149 ± 65 ml. All patients underwent robot-assisted distal pancreatectomy without conversion. The average pain score on postoperative day (POD) 3 was 4.5 ± 1. Complications included subsplenic hematoma (n = 1) and minor pancreatic leakage (n = 2). There was no surgical mortality. CONCLUSIONS: Our results demonstrate the safety and efficiency of robotic single-incision distal pancreatectomy via the modified platform (LAGIPORT®).

Transforming growth factor beta 1 increases collagen content, and stimulates procollagen I and tissue inhibitor of metalloproteinase-1 production of dental pulp cells: Role of MEK/ERK and activin receptor-like kinase-5/Smad signaling.

BACKGROUND/PURPOSE: In order to clarify the role of transforming growth factor beta 1 (TGF-ß1) in pulp repair/regeneration responses, we investigated the differential signaling pathways responsible for the effects of TGF-ß1 on collagen turnover, matrix metalloproteinase-3 (MMP-3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) production in human dental pulp cells. METHODS: Pulp cells were exposed to TGF-ß1 with/without pretreatment and coincubation by 1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenyl mercapto)butadiene (U0126; a mitogen-activated protein kinase kinase [MEK]/extracellular signal-regulated kinase [ERK] inhibitor) and 4-(5-benzol[1,3]dioxol-5-yl-4-pyrldin-2-yl-1H- imidazol-2-yl)-benzamide hydrate (SB431542; an activin receptor-like kinase-5/Smad signaling inhibitor). Sircol collagen assay was used to measure cellular collagen content. Culture medium procollagen I, TIMP-1, and MMP-3 levels were determined by enzyme-linked immunosorbent assay. RESULTS: TGF-ß1 increased the collagen content, procollagen I, and TIMP-1 production, but slightly decreased MMP-3 production of pulp cells. SB431542 and U0126 prevented the TGF-ß1-induced increase of collagen content and TIMP-1 production of dental pulp cells. CONCLUSION: These results indicate that TGF-ß1 may be involved in the healing/regeneration processes of dental pulp in response to injury by stimulation of collagen and TIMP-1 production. These events are associated with activin receptor-like kinase-5/Smad2/3 and MEK/ERK signaling.

Toxic mechanisms of Roth801, Canals, microparticles and nanoparticles of ZnO on MG-63 osteoblasts.

ZnO eugenol-based materials are widely used for restoration of caries cavity, apical retrograde filling and root canal sealer. Their effects on apical bone healing await investigation. The toxic mechanisms of ZnO particles and nanoparticles to MG-63 osteoblastic cells were studied. We found the different morphology and size of various particles as observed by scanning electron microscope. Particles of Canals and Roth801 were larger than ZnO-205532 microparticles and ZnO-677450 nanoparticles. Four ZnO particles showed cytotoxicity (>25 µg/ml) as analyzed by MTT. Transmission electron microscope found intracellular vacuoles with particle content. Exposure to ZnO particles induced ROS production and cell cycle arrest as studied by DCF and propidium iodide flow cytometry. ZnO particles activated ATM, ATR, Chk1, Chk2, γ-H2AX, ERK and p38 phosphorylation as detected by immunofluorescent staining and western blotting. The protein expression of cdc2, cyclin B1 and cdc25C were decreased, whereas GADD45α and hemeoxygenase-1 (HO-1) were stimulated. ZnO particles' cytotoxicity to MG63 cells was prevented by N-acetylcysteine (NAC), but not CGK733, AZD7762, U0126 and SB203580. ZnO showed little effect on IL-8 and sICAM-1 secretion. These results indicated that ZnO particles are toxic to osteoblasts. ZnO particles' toxicity were related to ROS, and DNA damage responses, checkpoint kinases, cell cycle arrest, ERK and p38 signaling, but not IL-8 and ICAM-1. These results were useful for materials' development and promote apical healing. Dentists should avoid of extruding ZnO-based sealers excessively over root apex and prevent residual ZnO-based retrograde filling materials in apical area during endodontic practice.

Clinical and Radiographic Characteristics of Vertical Root Fractures in Endodontically and Nonendodontically Treated Teeth.

INTRODUCTION: A vertical root fracture (VRF) is a root fracture extending along the longitudinal axis of roots and is often noted in endodontically treated teeth. However, the clinical and radiographic characteristics of VRFs are not completely known. METHODS: A total of 65 teeth with 68 vertical fractured roots in 58 Chinese patients were investigated. The clinical examination records and radiographic images were reviewed in detail. RESULTS: A total of 24 male (41.38%) and 34 female (58.62%) patients aged 25-90 years (average = 57 years) were included; 51 (87.93%) and 7 (12.07%) patients exhibited 1 tooth and 2 teeth with VRFs, respectively, in the dentition. VRFs occurred mainly in the mesial root (20 roots, 57.14%) of the mandibular molars (29 teeth, 44.62%). Clinically, teeth with VRFs usually presented a periodontal probing depth >5 mm (44 teeth, 91.67%, P < .001) with a prosthesis (55 teeth, 84.62%, P < .001) and a relatively intact dentition (42 patients exhibited <4 missing teeth in the dentition, 77.78%, P < .001). Most of the nonendodontically treated VRFs exhibited attrited occlusal surfaces. Radiographic characteristics of the teeth with VRFs were typically associated with prior root canal treatment (56 teeth, 86.15%, P < .001), periodontal bone loss (62 teeth, 95.38%, P < .001), apical bone loss (52 teeth, 80.00%, P < .001), and periodontal ligament widening (61 teeth, 93.85%, P < .001). The mesial roots of the mandibular molars were most susceptible to VRFs in both endodontically and nonendodontically treated teeth. CONCLUSIONS: These results elucidated some clinical and radiographic and diagnostic features that facilitate VRF identification.

Effect of Butyrate on Collagen Expression, Cell Viability, Cell Cycle Progression and Related Proteins Expression of MG-63 Osteoblastic Cells.

AIMS: Butyric acid is one major metabolic product generated by anaerobic Gram-negative bacteria of periodontal and root canal infection. Butyric acid affects the activity of periodontal cells such as osteoblasts. The purposes of this study were to investigate the effects of butyrate on MG-63 osteoblasts. METHODS: MG-63 cells were exposed to butyrate and cell viability was estimated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The mRNA and protein expression of type I collagen and cell cycle-related proteins were measured by reverse-transcriptase polymerase chain reaction (RT-PCR), western blotting or immunofluorescent staining. Cellular production of reactive oxygen species (ROS) was analyzed by 2',7'-dichlorofluorescein (DCF) fluorescence flow cytometry. RESULTS: Exposure to butyrate suppressed cell proliferation, and induced G2/M (8 and 16 mM) cell cycle arrest of MG-63 cells. Some cell apoptosis was noted. The mRNA expression of cdc2 and cyclin-B1 decreased after exposure to butyrate. The protein expression of type I collagen, cdc2 and cyclin B1 were decreased, whereas the expression of p21, p27 and p57 was stimulated. Under the treatment of butyrate, ROS production in MG-63 cells markedly increased. CONCLUSIONS: The secretion of butyric acid by periodontal and root canal microorganisms may inhibit bone cell growth and matrix turnover. This is possibly due to induction of cell cycle arrest and ROS generation and inhibition of collagen expression. These results suggest the involvement of butyric acid in the pathogenesis of periodontal and periapical tissue destruction by impairing bone healing responses.

Morphologic study of Nd:YAG laser usage in treatment of dentinal hypersensitivity.

Our previous in vitro study indicated that Nd:YAG laser irradiation on dentin could melt normal dentin surface and close the exposed dentinal tubule orifices without creating surface cracks. This study evaluated the morphologic changes of hypersensitive dentin after Nd:YAG laser irradiation. Thirty patients with clinically diagnosed cervical dentin hypersensitive teeth were treated with a Nd:YAG laser of 30 mJ intensity at 10 pulses per second for 2 min. An impression of the sensitive area was taken before and after laser treatment and then examined with a scanning electron microscope. The impression of the dentin surface after Nd:YAG laser treatment showed no protrusive rods, in contrast with the presence of numerous rods before laser irradiation. Because protrusive rods are a measure of open dentinal tubules, we interpret these data to support the hypothesis that Nd:YAG laser irradiation at specifications of 30 mJ, 10 pulses per second, and 2 min can be used to seal the exposed dentinal tubules.