Effects of circadian rhythm on the development of dental hard tissues / 中华口腔医学杂志

Circadian rhythm is regulated by circadian clock, which is formed by the body response to external cyclic stimuli through the endogenous circadian clock. Circadian rhythm disturbance is closely related to the risks of a variety of diseases, and its impact on oral health cannot be ignored. Exploring the relationship and related molecular mechanism between circadian rhythm and dental hard tissues development are helpful to deeply understand the pathogenesis of developmental defects on these tissues, which could provide a theoretical basis for prevention and treatment on disorders of dental hard tissues. In order to provide guidance for the disease prevention and treatment, based on the summarization of current research progress, this paper focuses on the involvement of biorhythm in the development of tooth hard tissues as well as the disturbance of circadian rhythm on the formation of enamel and dentin, and analyzes the related regulating mechanism of circadian rhythm and genes during the development of tooth hard tissues.

An in vitro model study of computer-guided endodontic microsurgery / 中华口腔医学杂志

Objective: To assess and compare the accuracies and operating time of endodontic microsurgery performed by operators with different levels of experience in endodontics using computer-guided techniques including dynamic and static navigations in a surgical simulation model. Methods: Six pairs of three dimensional (3D)-printed models of upper and lower jaws were set up on dental manikins. A total of 120 teeth (10 teeth each jaw) were included in the models. Microsurgeries of osteotomy and root-resection were performed on the models by two operators with different experience, namely novices and experts, under of free hand (FH)(n=20), dynamic navigation (DN)(n=20), and static navigation (SN)(n=20) conditions, respectively. The duration of each operation was recorded. Cone-beam CT was taken for 3D-printed models before and after the operation. The path of preoperative surgery planning was simulated. The linear deviations at the entry and the end point and the angular deviation of the access path between the simulated and the actual operation were compared by the software. Results: Significant difference of the entry deviation was observed between the novices and the experts in the FH group [(1.44±0.49) and (1.02±0.58) mm] (q=4.67, P=0.020). There were no significant differences between the novices and the experts in the end point and angular deviations (P>0.05). For the novices, the entry deviations in both DN and SN groups [(0.76±0.32) and (0.66±0.20) mm] were significantly lower than those in FH group (q=7.58, P<0.001; q=8.66, P<0.001). The angular deviations in the abovementioned two groups (5.0°±3.5°, 3.9°±2.1°) were significantly lower than that in FH group (10.9°±6.1°) (q=7.38, P<0.001; q=8.70, P<0.001). For the experts, significant differences were found only in the angular deviations among DN, SN and FH groups (3.6°±1.9°, 3.2°±1.7° and 8.2°±3.9°) (q=5.74, P=0.001; q=6.29, P<0.001). The operation durations were significantly shortened for both the novices [(4.80±2.15), (1.09±0.48) min] (q=14.60, P<0.001; q=20.10, P<0.001) and the experts [(3.40±1.96),(1.02±0.34) min] (q=5.86, P<0.001; q=9.37, P<0.001) by using DN and SN techniques. Regarding the differences between tooth types, in FH group, the operating time on the anterior teeth was significantly shorter than that on the posterior teeth (q=8.14, P<0.001; q=5.20, P=0.007), while in DN and SN groups, there were no significant differences in the operating time between two tooth types (P>0.05). No significant differences were discovered in the accuracies on the anterior and posterior teeth among three techniques or between two kinds of operators (P>0.05). Conclusions: Dynamic and static navigation techniques could assist the clinicians, especially the novices, to improve the accuracies and shorten the operating time of osteotomy and root resection microsurgeries.

DLX4 is associated with orofacial clefting and abnormal jaw development.

Cleft lip and/or palate (CL/P) are common structural birth defects in humans. We used exome sequencing to study a patient with bilateral CL/P and identified a single nucleotide deletion in the patient and her similarly affected son­c.546_546delG, predicting p.Gln183Argfs*57 in the Distal-less 4 (DLX4) gene. The sequence variant was absent from databases, predicted to be deleterious and was verified by Sanger sequencing. In mammals, there are three Dlx homeobox clusters with closely located gene pairs (Dlx1/Dlx2, Dlx3/Dlx4, Dlx5/Dlx6). In situ hybridization showed that Dlx4 was expressed in the mesenchyme of the murine palatal shelves at E12.5, prior to palate closure. Wild-type human DLX4, but not mutant DLX4_c.546delG, could activate two murine Dlx conserved regulatory elements, implying that the mutation caused haploinsufficiency. We showed that reduced DLX4 expression after short interfering RNA treatment in a human cell line resulted in significant up-regulation of DLX3, DLX5 and DLX6, with reduced expression of DLX2 and significant up-regulation of BMP4, although the increased BMP4 expression was demonstrated only in HeLa cells. We used antisense morpholino oligonucleotides to target the orthologous Danio rerio gene, dlx4b, and found reduced cranial size and abnormal cartilaginous elements. We sequenced DLX4 in 155 patients with non-syndromic CL/P and CP, but observed no sequence variants. From the published literature, Dlx1/Dlx2 double homozygous null mice and Dlx5 homozygous null mice both have clefts of the secondary palate. This first finding of a DLX4 mutation in a family with CL/P establishes DLX4 as a potential cause of human clefts.

Reciprocal effects between microRNA-140-5p and ADAM10 suppress migration and invasion of human tongue cancer cells.

ADAM10, overexpressed in tongue squamous cell carcinoma (TSCC), has been well documented for its role in tumor progression and metastasis. In the present study, we evaluated the inhibition effect of microRNAs (miRNAs) on the TSCC and identified that miR-140-5p could directly targets ADAM10 and inhibits the invasion and migration of TSCC cells. LAMC1, HDAC7 and PAX6, clustered into migration-related genes, were validated to be direct targets of miR-140-5p, while IGF1R and PSEN1 were not responsible to the regulation. Most intriguingly, ERBB4 was upregulated by miR-140-5p even though the interaction between ERBB4 3'UTR and miR-140-5p existed simultaneously. Meanwhile, ADAM10 is involved in the "positive" regulation of ERBB4 and negative regulation of PAX6 by miR-140-5p. Taken together, our results suggest that miR-140-5p play a role in TSCC cell migration and invasion, and two brand new relationships between miRNA and its targets emerged: (1) ADAM10 is not just a direct target of miR-140-5p, the repressed ADAM10 also helps to enhance the effect of miR-140-5p to other target genes: ERBB4 and PAX6; (2) ERBB4 is "positively" regulated by miR-140-5p.

The shaping ability of manual ProTaper on mandibular second molars / 实用口腔医学杂志

Investigate the cleaning ability of manual ProTaper on mandibular second molars with C-shaped (c-shaped root) or normal root canal(separated root). Twenty mandibular second molars with C-shaped root or with separated roots were sectioned at 3.0, 5.5 and 8.0 mm from the root apex. The images of pre-preparation and F1, F2, and F3-prepapared of manual ProTaper were captured respectively. The cross-sectional areas of the canals were measured and the formula of area after treatment/area before treatment was used to calculate the area ratio. The data were analyzed by SPSS 10.0. The results showed that there was no statistically difference between cross-section root canal area ratios in two groups. Significant differences were found between the cross-section canal area ratio of F1 and F2, F1 and F3 at section 5 mm of S group, and F1 and F3 at section 3 mm of C group. The results suggested that the increasing of cross-section ratio of the two kinds of canals was not obviously concerned with their anatomical morphology.

Evaluation of preparation of curved root canals using hand-used ProTaper / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the shaping ability of hand-used ProTaper on curved canals using Endodontic Cube.</p><p><b>METHODS</b>Fifty-four curved root canals in vitro were selected and divided into three groups according to the curved degree (alpha), group A: 0 degrees < or = alpha < 25 degrees , group B: 25 degrees < or = alpha < 40 degrees , group C: 40 degrees < or = alpha < 55 degrees . Endodontic Cube was assembled, and each sample was sectioned perpendicular to the axis of the tooth into four sections with Isomer-Buhler in low speed. Then the root canals were prepared with hand-used ProTaper. Before and after shaping, photograph of all the sections were taken under a stereomicroscope. Statistical analyses were performed.</p><p><b>RESULTS</b>The dentin cutting quantity of the whole canal prepared with ProTaper in group B and C was larger than that of group A. The deviation distance of the whole canal prepared by ProTaper in group C was significantly larger than that in group A, and the deviation distance in middle portion larger than that in group B. The maintaining ability in the middle portion of group C by ProTaper was worse than that of group A and B.</p><p><b>CONCLUSIONS</b>The curvature of root canal may increase the cutting quantity of the -dentin and reduce the ability of remaining original canal shape prepared by ProTaper.</p>

Mutations in the ED1 gene in families with X-linked hypohidrotic ectodermal dysplasia / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To detect mutations in the ED1 gene in two Chinese pedigrees and a sporadic case with X-linked hypohidrotic ectodermal dysplasia (XLHED) and provide evidences with the mutation analysis for genetic counseling, prenatal diagnosis and confirmation of carrier status.</p><p><b>METHODS</b>Peripheral blood samples were obtained from two pedigrees and the sporadic patient, and genomic DNA was extract by salting out method. Polymerase chain reaction (PCR) and direct sequencing were performed to screen mutations in ED1 gene.</p><p><b>RESULTS</b>Three mutations were identified. In one of the pedigrees, a 1045G > A transition was evidenced in exon 9 that resulted in a change of Ala 349 Thr. In the other pedigrees and the sporadic patient, 467G > A and 466C > T transitions were demonstrated in exon 3 that resulted in change of Arg 156 His and Arg 156 Cys. These mutations were not found in 100 normal individuals.</p><p><b>CONCLUSIONS</b>These mutations were responsible for the disease in the two families and the sporadic patient. All these mutations had been identified previously.</p>

Location of GbpC protein in Streptococcus mutans UA159 / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine whether the glucan binding protein C (GbpC) with LPXAG motif is anchoring to the cell wall of the Streptococcus mutans UA159 (S. mutans UA159).</p><p><b>METHODS</b>S. mutans UA159 GbpC C terminal gene segment was amplified by PCR, the gene sequences and the deduced amino acid sequences were analyzed. In order to locate the GbpC of S. mutans, the study isolated the wall fraction following digestion of the cell wall by N-acetylmuramidase, and the GbpC was detected by Western blot analysis. GbpC S. mutans UA159 was located with gold particles. Furthermore, the dextran-dependent aggregation (ddag) phenotype of the S. mutans UA159 under stress condition was observed.</p><p><b>RESULTS</b>S. mutans UA159 GbpC C-terminal LPXTG motif was replaced by LPXAG motif. GbpC was observed in the cell wall component and immunogold experiment showed that the gold particles distributed around the cell wall surface. S. mutans UA159 exhibited ddag+.</p><p><b>CONCLUSIONS</b>GbpC with LPXAG motif was still anchoring to the cell wall.</p>

Survey of root canal curvature in maxillary anterior teeth / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate root canal curvature in maxillary anterior teeth.</p><p><b>METHODS</b>About 400 human maxillary anterior teeth were examined by indirect digital radiography both from labiolingual and mesiodistal directions. The root canal curvature was analyzed.</p><p><b>RESULTS</b>The major sort of maxillary anterior teeth was type I. The proportion of maxillary center incisors, maxillary lateral incisors, maxillary canines curved in mesiodistal were 11.17%, 16.19% and 21.43%, in labio-lingual were 39.59%, 40.00% and 29.59%, both in labiolingual and mesiodistal directions were 4.60%, 35.24% and 24.49%. About 50% of maxillary anterior teeth were moderate curve, the degree of root canal curvature of maxillary canines was larger than that of maxillary incisors, and radius of curvature and length of the curved part of root canal of maxillary canines were smaller than that of maxillary incisors.</p><p><b>CONCLUSION</b>Root canal curvature in maxillary anterior is complex, especially in maxillary canine. In order to improve quality of root canal therapy, we need to understand types of root canal, degree of root canal curvature and radius of curvature completely.</p>

Immunolocalization of Secretion complex in Streptococcus mutans / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the distribution pattern of the Secretion complex in Streptococcus mutans by means of the subcellular localization of SecA and SecY.</p><p><b>METHODS</b>The specificity of anti-SecA antibody and the anti-SecY antibody were examined by Western blot. An indirect postembedding immunogold method was used to determine the subcellular localization of the SecA and SecY in the cytoplasmic membrane of the Streptococcus mutans GS-5.</p><p><b>RESULTS</b>Immunoblotting results showed that the anti-SecA antibody and the anti-SecY antibody specifically recognized a single band of about 95 000 and 47 800 respectively. Immunogold electron microscopy revealed a single intense focus of gold particles at a discrete location on the cytoplasmic membrane of the Streptococcus mutans GS-5.</p><p><b>CONCLUSIONS</b>SecA and SecY clustered to an asymmetric microdomain, which suggests that Sec complex present a uni-site on the cytoplasmic membrane of Streptococcus mutans.</p>

A study of the physicochemical and biological properties of mutanase from Trichoderma harzianum / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the physicochemical properties of the mutanase of Trichoderma harzianum isolated from China and to study the influence of mutanase on the adherence of oral Streptococci and the structure of oral biofilms.</p><p><b>METHODS</b>Six fungal strains belonging to Trichoderma were tested for mutanase production in the same cultural condition, the strain producing the highest mutanase activity was studied further and the pH and temperature optimum of the enzyme was determined. The RT-PCR method was used to obtain the gene coding for mutanase and the product was cloned to pMD18-T simple vector for sequencing. Inhibition effects of mutanase on the adherence of Streptococcus sobrinus OMZ176, Streptococcus sobrinus 6715, Streptococcus mutans MT8148 were studied by adherence test. The optical sectioning of biofilms with or without mutanase supplementation were analyzed by confocal laser scanning microscopy (CLSM).</p><p><b>RESULTS</b>The highest enzymatic activity was achieved by Trichoderma harzianum Th1, the maximum activity was at pH 5.5 and at 40 degrees C. The nucleotide sequence was 92% homology with that of a known gene coding a mutanase (GenBank accession No. AJ243799). The adherence of Streptococcus sobrinus OMZ176, Streptococcus sobrinus 6715, Streptococcus mutans MT8148 was significantly inhibited by mutanase. Compared with control, the biofilms with mutanase supplementation had lower height and sparser structure.</p><p><b>CONCLUSIONS</b>The mutanase from Trichoderma harzianum Th1 can inhibit the adherence of oral Streptococci and had an influence on the structure of oral biofilms.</p>

Comparison of penetration and obturation density using nickel-titanium and stainless-steel spreader in curved canals / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To compare the initial penetration depth of nickel-titanium (NiTi) and stainless-steel (SS) spreader during lateral compaction and the quality of the seal in curved canals.</p><p><b>METHODS</b>Forty extracted mandibular premolars with a single curved canal were divided into two groups: no more than 20 degrees and more than 20 degrees based on degree of curvature. All canals were instrumented using a rotary instrumentation technique. NiTi and SS spreaders were used to obturate the canals containing a master cone while the penetration depths were measured. Horizontal sections were cut in 2 and 4 mm from the apex and photographed under stereomicroscope. The percentage of gutta-percha-filled are (PGP) of cross-sections was measured using an image analysis program.</p><p><b>RESULTS</b>In canals of more than 20 degrees, the penetration depths and PGP of 2 mm from the apex of NiTi spreaders were higher than SS spreader. In canals of no more than 20 degrees, there were no significant difference between them (P > 0.05). At 4 mm from the apex, there was no significant difference between two groups.</p><p><b>CONCLUSION</b>NiTi spreaders has a higher penetrated depth and obturation density than SS spreaders in severed curved canals.</p>

Ultrastructure of the taste pores and taste pits of human taste buds / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To observe the ultrastructural features of taste pores and taste pits of human taste buds.</p><p><b>METHODS</b>Three samplers obtained randomly from adults were divided into two perts, and transmission electron microscopy and scanning electron microscopy were used to observe the fine structure of taste buds in human circumvallate papillae.</p><p><b>RESULTS</b>The longer diameter of the taste pores was 1.02 - 7.36 microm, and most of taste pores contained no taste hair and dense material, and the profile of taste pit was triangular.</p><p><b>CONCLUSIONS</b>Taste hair and dense material were seldom observed in most of taste pores.</p>

Expression pattern and level of cytotoxic T lymphocyte-associated antigen-4 targeted anti-caries plasmids in eukaryotic cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate and compare the expression pattern and level of targeted anti-caries plasmids encoding different-size antigens in eukaryotic cells.</p><p><b>METHODS</b>The A-P fragment of PAc (surface protein antigen) was removed from pGJA-P encoding the signal peptide, extracellular domains of human CTLA-4, human Ig hinge, CH2 and CH3 domains, A-P fragment of PAc and GLU (glucan binding domain) region of GTF-I of Streptococcus mutans, to obtain the plasmid pGJGLU. pCI vector skeleton of pGJA-P or pGJGLU was replaced by pVAX1 to construct plasmids pGJA-P/VAX and pGJGLU/VAX. CTLA4-Ig-GLU fragment was removed from pGJGLU and inserted into the vector pEGFP-N1 to obtain the recombinant plasmid pGJGLU/GFP. The CHO cells were transfected with those plasmids by using liposome and the expression of fusion protein was observed with fluorescence microscope. ELISA was used to detect the expression level of fusion proteins in cultured supernatants.</p><p><b>RESULTS</b>Specific vesicles with green fluorescence could be observed in the CHO cells transfected with pGJGLU/GFP. The recombinant fusion protein could be detected in the cultured supernatants of CHO cells transfected with pGJA-P/VAX, pGJGLU/VAX and pGJGLU/GFP, of which the concentration was different. The highest concentration of recombinant fusion protein was observed in the supernatants of CHO cells transfected with pGJGLU/VAX.</p><p><b>CONCLUSIONS</b>CTLA-4 targeted fusion protein could be expressed and secreted by eukaryotic cells. The size of antigen may affect the expression level of CTLA-4 targeted anti-caries DNA vaccine.</p>

Clinicopathologic analysis and genetic investigation of two families with cherubism / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study genetic feature, clinical and histopathological characteristic of two Chinese kindreds with cherubism (CBM).</p><p><b>METHODS</b>Two Chinese kindreds with CBM were investigated. The affected individuals of two families were analyzed with medical history, clinical manifestations, classified grading system, radiographic assessment, histopathological findings, and hereditary nature.</p><p><b>RESULTS</b>There were 2 individuals affected with CBM in family A and 3 patients involving three generations in family B. Two probands were diagnosed aggressive form cherubism and classified as grade IV. In histopathological findings, besides varying numbers of multinucleated giant cells in a stroma of fibroblasts and the eosinophilic cuffing surrounding some vessels, actively proliferating areas with clear mitoschisis and relative dormant areas with loose fibrous tissue and bone were also presented in microscopic fields of the lesion.</p><p><b>CONCLUSIONS</b>Cherubism is caused by autosomal dominant inheritance. The diagnosis should be based on the genetic, clinical, radiological, and pathological aspects of the disease.</p>

Analysis on results of endodontic treatment and influencing factors / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To assess the clinical outcome of root canal therapy (RCT) and the various factors that may influence the outcome of RCT.</p><p><b>METHODS</b>A total of 695 teeth from 357 patients were retrospectively studied three years after endodontic treatment. Pre- and intra-operative information was collected from the original patient records. The post-operative sign or symptom, periapical status and coronal restoration integrity were examined 3 years after obturation. Data were subjected to bivariate and multivariate analysis.</p><p><b>RESULTS</b>The cure rate for 695 teeth was 75.1%, 96.0% of which was considered to be functional. The tooth group, pre-operative pulp and periapical status, quality of root filling and integrity of coronal restoration were revealed by means of bivariate analysis to exert a significant influence on treatment outcome. The logistic analysis indicated that the odds for cure in the teeth with pre-operative periapical radiolucency, underfilling and "open" coronal restoration were significantly lower by 2 folds, 3 folds and 1.6 folds than their counterparts, respectively.</p><p><b>CONCLUSIONS</b>The pre-operative periapical status, quality of root filling and the integrity of coronal restoration are main predictors of outcome in RCT.</p>

The study of salivary-SIgA reaction to Streptococcus mutans in acid environment / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To test the salivary immunoglobulin A antibody activity to Streptococcus mutans in normal with in acid environment.</p><p><b>METHODS</b>Streptococcus mutans strains were isolated from 20 volunteers, serotyped by biochemical test and PCR, and genotyped by AP-PCR. Unstimulated secretions from submandibular glands and sublingual glands were collected from volunteers by modified collectors. Each identified Streptococcus mutans genotype was cultured in two groups: control group was cultured in BHI broth pH7.2 at 37 degrees C for 2 h; acid shock group were cultured in TYEG broth (pH5.5) at 37 degrees C for 2 h. Analysis of SIgA activity to Streptococcus mutans genotypes in different groups was detected by Western blot.</p><p><b>RESULTS</b>(1) The SIgA of each individual could response to his own Streptococcus mutans strains and the reference strains; (2) The same individual had different SIgA activity to different genotype strains; (3) There were no significant difference between acid groups and control groups, in spite that some bands had strong or weak intensity.</p><p><b>CONCLUSIONS</b>Although Streptococcus mutans could express acid shock proteins in stress, the present study suggests that these new proteins have no qualitative effect on the reaction of SIgA to Streptococcus mutans.</p>

Chitosan-DNA microparticles as mucosal delivery system: synthesis, characterization and release in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mucosal immunity is important to defense against dental caries. To enhance mucosal immunity, a DNA vaccine mucosal delivery system was prepared by encapsulating anticaries DNA vaccine (plasmid pGJA-P/VAX) in chitosan under optimal conditions and the characteristics of the microparticles was investigated. Furthermore, the release properties and protective action of microparticles for plasmid were studied in vitro.</p><p><b>METHODS</b>Plasmid loaded chitosan microparticles were prepared by complex coacervation. Three factors, concentration of DNA, sodium sulfate, and the chitosan/DNA ratios in complexes [better expressed as N/P ratio: the number of poly nitrogen (N) per DNA phosphate (P)] influencing preparation were optimized by orthogonal test. The characteristics of microparticles were evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). DNA release rate of microparticles in similar gastro fluid (SGF) or similar intestinal fluid (SIF) at 37 degrees C was determined by ultraviolet spectrophotometry.</p><p><b>RESULTS</b>High encapsulation efficiency (96.8%) was obtained with chitosan microparticles made under optimal conditions of 50 mmol/L Na2SO4, 200 microg/ml DNA and N/P ratio of 4. The size of particles was about 4 to 6 microm. The encapsulation process did not destroy the integrity of DNA. When incubated with SIL, after a release of about 10% in the first 60 minutes, no further DNA was released during the following 180 minutes. When incubated with SGL, the microparticles released a small burst (about 11%) in the first 60 minutes, and then slowly released at a constant, but different rate.</p><p><b>CONCLUSIONS</b>These chitosan microparticles showed suitable characteristics in vitro for mucosal vaccination and are therefore a promising carrier system for DNA vaccine mucosal delivery.</p>

The value of endoscopy for the diagnosis and treatment of obstructive salivary gland diseases / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the value of sialoendoscopy in the diagnosis and treatment of chronic obstructive sialadenitis (COS).</p><p><b>METHODS</b>25 patients (34 sides) who complained of recurrent swelling in the salivary gland region were selected for study from Jan. 2003 to Jun. 2003 at the Department of salivary gland diseases, School of Stomatology, Wuhan University, including 19 parotid cases (27 sides) and 6 submandibular gland cases (7 sides); 16 females and 9 males. And their age range was 17 - 77 years, with an average of 43.72 years. Before sialoendoscopy, 22 parotid cases underwent sialography, and 3 submandibular gland sialoliths cases received an additional standard mandibular occlusal film examination.</p><p><b>RESULTS</b>Conventional radiographs revealed that 3 cases had submandibular gland radiopaque stones, and 22 had COS. Dilatation of main duct of parotid and submandibular gland were also found in the radiographs. Sialoendoscopy showed: proliferative fibrous materials in the duct; stenosis or dilatation of duct; vasodilatation, erythema on the wall of the duct; mucoid plugs and pyogenic plugs; irregular lumen shape; radiopaque and radiolucent stones.</p><p><b>CONCLUSIONS</b>Sialoendoscopy may be a safe, effective, and minimal invasive method in the diagnosis and treatment of COS.</p>

The effect of left bacteria in the root canal on prognosis of the root canal therapy / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the effect of the left bacteria on the root canal therapy.</p><p><b>METHODS</b>50 single-rooted teeth with chronic apical periodontitis were divided into two groups, one was instrumented with step-back technique and 2.5%NaOCl ultrasonic irrigation for 3 min, then filled with Thermafil. Samples were taken after instrumentation to culture. The other was treated with traditional RCT at three visits.</p><p><b>RESULTS</b>In 24 months the apical radiolucency were greatly reduced in all cases. There weren't significant relationship among the postoperative pain and the left bacteria, the degree of the obturation or the pre-operative symptoms (P > 0.05).</p><p><b>CONCLUSION</b>The effect of left bacteria in root canal filled with Thermafil wasn't observed.</p>