No abstract

No abstract

Objective: The aim of this study was to evaluate the effect of an erbium, chromium: yttrium-scandium-galliumgarnet (Er,Cr:YSGG) laser on the push-out bond strength of RealSeal Self-Etch (SE) sealer. Background data: Various methods are used for smear layer removal in endodontics, such as the application of Er,Cr:YSGG lasers. This laser system may influence the bond strength of resin-based sealers. Methods: Sixty single-rooted extracted teeth were selected. After root canal preparation, samples were divided into two experimental groups and one positive control group (n = 20 per group). In group 1, the smear layer was removed by irrigation with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl). In group 2, the smear layer was removed using a 2.78 lm Er,Cr:YSGG laser with radial firing tips (RFT3) (parameters: 1.5W, 140 ls, 20 Hz, and 15% water to 15% air ratio), moving at 2 mm/sec in an apico-coronal direction. Group 3 served as a positive control group. Five specimens from each group were selected for scanning electron microscope (SEM) observation. The remaining 45 roots were obturated with RealSeal SE/Resilon and subjected to push-out tests. Data were analyzed using one way analysis of variance (ANOVA) and Tamhane's test. Results: The results showed no significant difference between push-out bond strength of root canal fillings in the EDTA + NaOCl group and the 1.5W laser group ( p > 0.05). The positive control group showed the lowest push-out bond strength. Conclusions: The results of the present study indicate that the application of an Er,Cr:YSGG laser with radial firing tips did not adversely affect the push-out bond strength of RealSeal SE sealer to dentin.

No abstract

No abstract

Background: PRF as one of the favorable scaffolds in Regenerative Endodontic Treatment (RET), has several limitations such as the need for blood sampling and special equipment. High available commercial scaffolds such as fibrin are able to meet all the necessary requirements of dentin tissue engineering. The present study was designed to evaluate the effect of PRF and fibrin gel, with and without the presence of EDTA-treated radicular dentin segments on SCAP viability, proliferation, migration, and differentiation.Methods: Radicular dentin were prepared from extracted teeth and treated by EDTA 17% .The samples were divided into 6 groups: Dentin/PRF/Cell, Dentin/Fibrin/Cell, Dentin/Cell, PRF/Cell, Fibrin/Cell and Cell (Control). SCAP viability was assessed using MTT assay. Gene expression levels of odontogenic markers [Dentin sialophosphoprotein (DSPP), Dentin matrix protein 1(DMP1), Collagen type I Alpha 1(COL 1A1) and Alkaline phosphatase (ALP) were assessed using qrt-PCR. Cell migration were also evaluated by means of scratch test. Results: The results of MTT assay at showed that the viability of SCAP significantly increased after 7 days for both groups containing fibrin (P <0.05). The viability of SCAP seeded on Dentin/PRF and PRF significantly decreased after 7 days (P <0.001). The odontogenic markers were significantly expressed for both scaffolds in the presence of dentin segment (p<0.05). Significant decrease in scratch area was seen in Fibrin/Dentin group (p < 0.001)Conclusions:Fibrin beside EDTA-treated dentin showed great ability in survival, proliferation, differentiation, and migration of SCAP rather than PRF.

C leaning and shaping are essential steps in root canal treatment procedures for removing debris and microorganisms that are responsible for endodontic pathosis. [1,2] Since the introduction of nickel-titanium (NiTi) rotary instruments, it has ABSTRACT Objectives: Using one rotary fi le can result in a faster canal preparation. This can be done with several fi le systems and endodontic motors. In the present study, a newly single fi le technique (one rotary fi le technique) with available rotary fi le systems is introduced. The aim of the present study was to evaluate centering ability and remaining dentin thickness of 2 rotary nickel-titanium systems (Mtwo versus RaCe) and instrumentation techniques (conventional versus one rotary fi le) by cone-beam computed tomography. Materials and Methods: A total of 76 mandibular molar teeth were selected and divided to 4 groups (n = 19 teeth with 57 canals). The teeth were mounted in resin and pre-instrumentation scans were prepared by Cone Beam Computed Tomography (CBCT). The canals instrumented with Mtwo and RaCe rotary fi les either in conventional or one rotary fi le technique (ORF). After cleaning and shaping of distal and mesial canals, post instrumentation scans were performed by CBCT in the same position as pre instrumentation scans. Centering ability and remaining dentin thickness were evaluated by Planmeca Romexis viewer. The data were analyzed with analysis of variance and post hoc t test (P < 0.05). Results: Mean centering ratios for Mtwo/conventional, Mtwo/ORF, RaCe/conventional and RaCe/ ORF groups were assessed. At overall, there were no signifi cant differences between instrument types and instrumentation techniques (P > 0.05). However, in a few cross-sections, conventional technique and/or RaCe showed higher centering ability. One rotary fi le technique with either RaCe or Mtwo was signifi cantly faster than conventional technique (P = 0.02). There was no signifi cant difference among groups regarding fi le fracture. Mesiolingual canals showed more transportation compared with mesiobuccal and distal canals. Conclusions: Both of the instrumentation systems and techniques produced canal preparations with adequate centering ratio. One rotary fi le technique prepared canal signifi cantly faster than conventional technique.

No abstract