Characterization of oral bacterial diversity of irradiated patients by high-throughput sequencing.

The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy. Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients. Eight patients with head and neck cancers were involved in this study.

[Effect of compound Chinese traditional medicine on periapical periodontitis in dogs and cytotoxic assay].

Purpose: To assess the efficacy of compound Chinese traditional medicine(CTM), which is composed of gallic acid, magnolol and polysaccharide of Bletilla, against apical periodontitis in dogs and cytotoxic assay.

Methods: A animal model of apical periodontitis was built, CTM was then used to disinfect the root canal. The effect of the restoration of periapical bone in dogs was investigated after regular root canal filling.

Six cases report of differential diagnosis of periapical diseases.

The distinction of some particular forms of periapical area, involving diseases from regular periapical disease, is a matter of considerable importance when choosing a correct treatment. The aim of this study is to describe the differential diagnosis of periapical diseases from six rare cases in clinical practice. The six rare cases are examples of situations where it is difficult to make a differential diagnosis in clinical practice.

[Effect of compound Chinese traditional medicine on infected root canal bacteria biofilm].

Purpose: To assess the efficacy of compound Chinese traditional medicine(CTM), which composed of gallic acid, magnolol and polysaccharide of Blettila striata, against the infected root canal bacterial biofilm.

Methods: Actinomyces viscosus (Av), Enterococcus faecalis (Ef), Fusobacterium nucleatum (Fn) were composed to form biofilm, then confocal laser scan microscope (CLSM) was used to observe and study the bacterial activity. SAS6.

[Quantitative evaluation of residual endodontic microorganisms after mechanical root canal preparation different chemical preparations by real-time PCR].

Purpose: To establish a quick, sensitive method for quantifying root canal flora and investigate the effects of different root canal preparations on the pathogenic bacteria at RNA level.

Methods: A total of 24 single-rooted teeth with chronic apical periodontitis were selected and prepared using 3% H2O2 combined with 1% NaClO, EDTA combined with 3% H(2)O(2),1% NaClO, respectively,the samples were taken before and after root canal preparation. After isolation of total RNA from the root canal samples, cDNA was synthesized by reverse transcription, and detected by real-time PCR.

[Cloning and the sequence analysis of the fish glutathione transferase Pi gene].

Using RT-PCR method, the glutathione transferase Pi cDNAs were cloned from Cyprinus carpio, Hypophthalmichthys molitrix, and Carassius auratus. The open reading frames (ORFs) from the 3 fishes were 627 bp long (encoding for 208 amino acids) with the initial code ATG and the terminal code TGA. The sequence similarity was 50% between fish and mammals, 33% between fish and amphibian, and 15% between fish and arthropoda, respectively.

[Analysis the stress variations of the root canal wall of pulpless tooth by different root canal preparation with finite-element method].

Objective: To analyze the stress variations of the root canal wall of pulpless tooth by different root canal preparations.

Methods: On the basis of the set up model of the mandibular first molar, modified model was established by simulation of the routine or step-back root canal preparation and filling in. Then the maximum mises stress of each part of teeth and wall of root canal were calculated by special finite-element software.

[Analysis the effect on the stress of wall of root canal by different proportion between crown and root].

Objective: Use FEM to observe the relationship between the change of alveolar ridge's height and the stress change of wall of root canal.

Methods: Modify the model on the basis of the set up model of the mandibular first molar, simulating the height of alveolar ridge and reducing 1/4, 1/3, 1/2 of the height to set up modified model, and load on the modified model by vertical and lateral forces. Then calculate the maximum mises stress of each part of teeth and wall of root canal.

[Analysis of the effect on the stress of root canal wall by vertical and lateral condensation procedures].

Objective: To analyse the stress variations of root canal wall that resulted from vertical and lateral condensation.

Methods: On the basis of the finite-element model of the mandibular first molar that modified by step-back technique, mesial-buccal root canal was chosen as tested root canal and simulated the procedure of vertical and lateral condensation. The maximal stress of root canal wall and its position were calculated by special software upon different loading condition.

[Histological evaluation on repair of furcation perforation in dogs using mineral trioxide aggregate].

Objective: To investigate histological response to immediate repair of different sizes of furcation perforation using MTA, Dycal and GIC.

Methods: Forty-two posterior teeth in three adult beagle dogs were randomly divided into two groups, small perforation group and large perforation group. Each group was then divided into three sub-groups which were repaired with MTA, Dycal and GIC respectively.

[Analysis the effect on the stress of root canal wall of pulpless teeth by different degree of root canal preparation].

Objective: To analyze the stress variations of wall of root canal of pulpless teeth that resulted from different diameters of root canal.

Methods: On the basis of the finite-element model of the mandibular first molar that modified by routine, diameter of root canal was modified and enlarged so as to the diameter of root canal was 1/3 and 1/2 of root diameter, then modified models were loaded and the maximal stress of each part of teeth and wall of root canal was calculated.

Results: The results revealed that enlargement of root canal diameter will bring on increase of stress of root canal wall at the orifice and coronal 1/3.