ali mahmoud hashemi

This study aimed to do a comprehensive systematic review on the comparison of digital and conventional workflows regarding prosthetic outcomes, accuracy of implant impressions, framework passivity and fit, and clinical fabrication of multi-unit implant-supported fixed restorations.

The EMBASE, PubMed, Scopus, and Cochrane Library databases were searched for relevant articles published up until April 2020.

No in-vivo article was found to compare full digital and conventional workflows regarding the accuracy of implant impressions, passivity and fit of frameworks, and prosthetic outcomes. There was no study to investigate full digital and conventional workflows for clinical fabrication of multi-unit implant-supported fixed restorations.

This empty review highlights the need for further research to compare full digital and conventional workflows for implant-supported restorations.

Statement of the Problem: 

Some components of implant treatment are reusable. Therefore, possible changes during fixation, removal, and sterilization process should be tested. Many studies have examined the reuse of implant parts, but the impact of repeated use of scan bodies on the accuracy of implant position has not been well investigated.

The aim of this in vitro study was to compare the effect of repeated use of two different types of scan bodies on the accuracy of implant position.

In this in vitro experimental study, two acrylic resin maxillary models, each with two implant analogues inserted at the site of missing first and second molars were used. Two types of scan bodies including titanium and polyetheretherketone (PEEK) were used for digital impression. Then they were ten times removed and autoclaved for sterilization. The first scan was considered as a reference to be compared with the other next nine scans. Values of linear distance between two scan bodies, diameter changes of each scan body, and three-dimensional linear displacement (ΔR) were measured. These values were compared between the two types of scan bodies using t-test (α=.05). 

There was significant difference between titanium and PEEK scan bodies regarding inter-implant distance variation (p=.006) and diameter change (p< .001) in repeated use. However, for the ΔR, there was no significant difference between them (p= 0.759).

The results demonstrated that type of scan body could affect the accuracy of implant position transfer after repeated use. PEEK scan body performed better after 9 cycles of reuse in comparison with titanium scan body.

Statement of the Problem: Quercetin is a pharmacological flavonoid that can inhibit high mobility group box1 (HMGB1) protein, a non-histone nuclear protein that is implicated in inflammation. Th17 cells are important cells in the pathogenesis of inflammation. Pulpitis is the inflammation of dental pulp, which usually is accompanied by pain. Quercetin may alleviate this inflammation. The current study aimed to compare blocking of HMGB1 function and stimulation of HMGB1 function with quercetin and investigate the effects of the blockage on T helper 17 (Th17) cells and mitogen-activated protein kinase Toll-like receptor 4 (MAPK-TLR4) signaling pathway. T cells isolated from the pulp involved with pulpitis and the normal pulp were cultured. The cells suspensions were plated in 6-wells culture plates and stimulated with 0.5 µg/ml of HMGB1 for 2, 4, 8, and 12 hours. For blocking TLR4, 10 µg/ml rabbit anti-human TLR4 antibody was added 1 hour before treatment with HMGB1. The level of these cytokines decreased; moreover, western blot data showed that quercetin could decrease MAPK signaling pathway by means of inhibition of HMGB1 on T cells. The results showed the reduction of TLR4 pathway and Th17 cell polarization. Our results indicated that the levels of IL-17, IL-33, and IL-6 in supernatants from patients’ cultured T cells were increased after stimulation with HMGB-1 following employing quercetin. It also could inhibit MAPK signaling pathway, which subsequently could decrease Th17 production and IL-17. Quercetin could decrease pro-inflammatory cytokines and IL-17 production.

Statement of the Problem: Oral squamous cell carcinoma is the most common oral malignancy. Toll-like receptor (TLR) activation led to alterations in the levels of mRNA encoding the TLR accountable for recognizing the inducing agonist and cross-regulation of other TLR.
The purpose of this study is determination of mitogen-associated protein kinase (MAPK) activation in human immortalized oral epithelial cell (HIOEC) line via up regulating of TLR7.
expression of TLR7 was measured in HIOEC and normal cells by quantitative real-time polymerase chain reaction (qRT-PCR) and samples were calibrated by β-actin.
Western blot analysis discovered high expression of TLR7 and MAPK in HIOEC cell lines. TLR7 was over-expressed in HIOEC cell line. Imiquimod-induced expression of interleukin (IL)-6, IL-8, and vascular endothelial growth factor (VEGF) was inhibited by TLR7 siRNA in HIOEC cells as determined by reverse transcription polymerase chain reaction (RT-PCR). Mean fluorescence intensity of nuclear p38 expression was determined in HIOEC cell lines (p TLR7 is functionally over-expressed in HIOEC cell line of oral squamous cell carcinoma and development of resistance to cisplatin in human oral squamous cell carcinoma might occur through the mechanism involving activation of TLR7 and its dependent signaling pathway.