Management of Separated Instruments Extruded into the Maxillary Sinus and Soft Tissue: a Case Series.

Extrusion of separated endodontic instruments is a frustrating complication that can occur during root canal treatment and is difficult to handle. This report aimed to introduce different methods to retrieve such separated instruments through three cases with different locations of fragments. Fragments extruded completely into the maxillary sinus, partially into the maxillary sinus and lying in the soft tissue were retrieved using a lateral window approach, ultrasonic method and minimally invasive surgery, respectively.

Evaluation of Silk Fibroin-RGD-Stem Cell Factor Scaffold Effect on Adhesion, Migration, and Proliferation of Stem Cells of Apical Papilla.

This study explored the effects of a silk fibroin-RGD-stem cell factor (SF-RGD-SCF) scaffold on the migration, proliferation, and attachment of stem cells of apical papilla (SCAPs). SF, SF-RGD, SF-SCF, and SF-RGD-SCF scaffolds were prepared, and laser confocal microscopy was used to observe the adhesion and growth status of SCAPs on the scaffolds. Furthermore, the numbers of SCAPs on the scaffolds were counted by a digestion counting method to evaluate their proliferation.

Morphological Changes of the Root Apex in Permanent Teeth with Failed Endodontic Treatment.

Objective: To determine the number, shape and diameter of apical foramina as well as changes in root apex morphology of permanent teeth with failed endodontic treatment.

Methods: Clinical records were collected for teeth diagnosed with posttreatment periapical periodontitis that subsequently underwent endodontic microsurgery. Resected root apices were examined with stereomicroscopy.

A screening method for gastric cancer by oral microbiome detection.

Gastric cancer is the second most common malig-nancy and one of the principal causes of cancer‑related mortality worldwide. Early diagnostic and screening methods for gastric cancer are limited at present, most of them involving invasive procedures. We aimed to investigate the characteristics of the oral microbiome in gastric cancer individuals and to conduct a screening method for gastric cancer by oral microbiome detection.

The incidence of root microcracks caused by 3 different single-file systems versus the ProTaper system.

Introduction: The aim of this study was to compare the incidence of root cracks observed at the apical root surface and/or in the canal wall after canal instrumentation with 3 single-file systems and the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland).

Methods: One hundred mandibular incisors were selected. Twenty control teeth were coronally flared with Gates-Glidden drills (Dentsply Maillefer).

Microbial diversity in failed endodontic root-filled teeth.

Background: Persistent/secondary infections of human root canals play an important role in the failure of endodontic treatment. This study used 16S rRNA sequencing to assess microbial diversity in root-filled teeth associated with failed endodontic treatment.

Methods: DNA was extracted from 15 teeth with persistent intraradicular infections, and the 16S rRNA of all present bacteria were amplified by PCR, followed by cloning and sequencing of the 16S rRNA amplicons.

[National examinations for dentist in Japan and implications].

Questions such as the law that was accorded by National Board Examinations for Dentist in Japan, the qualification of the examinee, the organization of the committee, the implementation of the exam, testing items development and the eligibility criteria were introduced in details in this article. The evolution of the number of qualified candidates and the issues for development needed to be explored were proposed.

[Treatment outcome of iatrogenic perforation repair by mineral trioxide aggregate].

Objective: To observe the clinical effect of iatrogenic perforation repaired by mineral trioxide aggregate (MTA).

Methods: Twenty-one iatrogenic perforation cases were included. The root canals were shaped and cleaned and then obturated after MTA was used to repair the perforation with microscopes.

[The effect of curvature of simulated root canal and location of fragment on removal of broken file from simulated root canal].

Objective: To evaluate effect of root canal curvature and location of the fragment on the removal of broken file from root canal.

Methods: Sixty extracted mandibular premolars were divided equally into six groups according to location of fragment (2 mm or 8 mm below root canal orifice) and root canal curvature (20 degrees, 30 degrees or 40 degrees). Broken files were removed using ultrasonic tips combined with dental operating microscope.

[Evaluation of homogeneity and density of root canal filling with four obturation techniques].

Objective: To evaluate the homogeneity and density of root canal filling with four obturation techniques.

Methods: Forty extracted single root teeth were randomly divided into four groups with 10 teeth each. Under simulated clinical conditions, the root canals were shaped with Nickle titanium rotary files (Protaper) using crown-down technique and were filled with warm vertically condensed gutta-percha (group A), core carrier technique-thermafil (group B), guttaflow (group C) and conventional cold laterally condensed gutta-percha (group D).

[Torque resistance of three different types of nickel-titanium rotary instruments].

Objective: To compare torsional fracture of three different types of nickel-titanium rotary instruments ProTaper, Hero642 and Mtwo by making a stimulate models in vitro.

Methods: Through the establishment of model in vitro, compared the different time with 3 kinds of nickel titanium file in cutting-edge bound occurs, and to observe the section of fractured instruments by scanning electron microscope.

Results: The resistence to torque was different from three types of nickel titanium instruments.

Bond strength of different adhesives to normal and caries-affected dentins.

Background: Currently, several systems of dentin substrate-reacting adhesives are available for use in the restorative treatment against caries. However, the bond effectiveness and property of different adhesive systems to caries-affected dentin are not fully understood. The objective of this study was to evaluate the bond strength of different adhesives to both normal dentin (ND) and caries-affected dentin (CAD) and to analyze the dentin/adhesive interfacial characteristics.

[Clinical effect of the use of dental operating microscope and ultrasonic instruments in the management of blocked canals].

Objective: To evaluate the effect of using dental operating microscope and ultrasonic instruments in treating blocked canals.

Methods: The etiology of canal blockage included calcification, broken instruments, posts, resinifying, etc. 236 blocked canals were treated with ultrasonic tips under dental operating microscope.

[Ultrasonic techniques for removing broken instruments from root canal].

Instruments broken in root canal is one of the frequent complications of endodontic therapy and fortunately, as the rapid development of microscope using in the root canal treatment, most of the broken instruments can be removed with the assistance of ultrasonic appliances. In the present study, we talked about the causes, the removing methods of broken instruments and troubles during the procedures. We put much emphasis on the creation of a straight pathway along the canal as well as some concerns in using the ultrasonic appliances, such as the water spray, the rotating actions and the assistance of microscope, all of which are supposed to offer great benefits for clinically avoiding as well as dealing with broken instruments.

[Expression of lipopolysaccharide receptors CD14 and TLR4 in a model of rat molar apical periodontitis].

Objective: To characterize the expression of lipopolysaccharide (LPS) receptors-CD14 and TLR4 in rat peri-radicular tissue and to investigate the signal transduction pathway of LPS and its receptors in periapical periodontitis.

Methods: After establishment of a model of rat molar LPS-induced apical periodontitis, CD14 and TLR4 expression in healthy and inflammatory periapical tissue were determined by immunohistochemistry.

Results: CD14 and TLR4 were not detected in healthy periapical tissue but strongly positive in inflammatory periapical tissue.

[Expression of lipopolysaccharides signal receptors CD14 and TLR4 in human dental pulp tissue and fibroblasts].

Objective: To investigate the expression of lipopolysaccharides (LPS) receptors CD14 and TLR4 in normal and inflamed human dental pulp tissue and fibroblasts and to determine the signal transduction pathway of LPS in pulpitis.

Methods: CD14 and TLR4 expression in healthy and inflammatory pulps was observed by immunohistochemistry. The rates of CD14 and TLR4 positive cells and the mean fluorescence intensity in in vitro cultured pulp fibroblasts before and after being stimulated by LPS.

[Secretory expression of sCD14 in Pichia pastoris and its LPS binding activity].

Aim: To achieve secretory expression of mature sCD14 gene in Pichia pastoris and to analyze its LPS binding activity.

Methods: sCD14 gene was cloned into yeast expression vector pPIC9K. Recombinant plasmid was lineared by Sac I and transformed into Pichia pastoris GS115.