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ABSTRACT: To evaluate the effect of periapical radiography in diagnosing the lesions of the apical periodontitis (AP) of posterior teeth, with CBCT imaging as a standard.
One hundred and six posterior teeth in 80 patients were examined by periapical radiography and CBCT, which consisted of healthy teeth (58 teeth), chronic pulpitis (11 teeth), chronic apical periodontitis (34 teeth), remnant teeth with normal apical images after root canal therapy (3 teeth). All images were measured and evaluated by two experienced dentists by using periapical index (PAI) to ensure the classifications. The results were analyzed statistically with SPSS 13.0 software package for X(2) test.
AP was identified in 39.6% and 59.4% of 106 cases by radiography and CBCT, the difference was significant (X(2)=8.32, P<0.01). The use of conventional radiography for detection of AP should be done with care because of the great possibility of artifacts which might lead to misdiagnosis. Because of its accuracy, CBCT is more useful for clinic diagnosis and therapy. Furthermore, the images of CBCT could show destruction of cortical bone that couldn't detect by periapical radiography.
CBCT is more accurate than periapical radiography for AP diagnosis. CBCT can reveal the details of the lesions and adjacent structures and provide correct clinical diagnosis and scientific treatment planning with accurate evidence. Supported by University Scientific Research Project of Bureau of Education of Liaoning Province(2008856).
Shanghai kou qiang yi xue = Shanghai journal of stomatology 08/2012; 21(4):442-6.
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ABSTRACT: To evaluate the effect of Carisolv on endodontic microleakage by establishing a fluid transport model using sodium nitrite as tracer.
Seventy extracted teeth were randomly divided into 5 groups, all the root canals were prepared with different chemical reagents, including Carisolv,3% hydrogen peroxide+ 2%tosylchloramide sodium,2.5% sodium hypochlorite,5% sodium hypochlorite(negative control)and distilled water(positive control),post spaces were prepared after cold lateral condensation, the samples were put on the model, concentration of sodium nitrite which penetrated from the coronal to the apical end was measured by diazo reaction at 1,2,4,7,10,15,20,25,30,35,40,45,50,55 and 60 day. The data were analyzed by ANOVA using SPSS 11.5 software package.
Sodium nitrite was not detected in negative control group from 1 day to 60 days. High concentration of sodium nitrite was detected in positive control group at first day, concentration of sodium nitrite was higher than that of other four groups from 1day to 60 days(P<0.01). Concentration of sodium nitrite in Carisolv group was significantly lower than that of 3%hydrogen peroxide+ 2% tosylchloramide sodium group(P<0.01), also lower than that of 2.5% sodium hypochlorite group(P<0.05),except at 25,30,35 and 40 days.
Carisolv can remove the smear layer, decrease the endodontic microleakage, seal the root canal better. The fluid transport model using sodium nitrite as tracer can be used to evaluate the endodontic microleakage objectively,sensitively and exactly.
Shanghai kou qiang yi xue = Shanghai journal of stomatology 04/2012; 21(2):145-8.
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ABSTRACT: To evaluate the clinical effect of root canal filling with warm vertical condensation with or without dental operating microscope.
Fifty maxillary anterior teeth with single, straight canals were divided into two groups. Each tooth was instrumented by X-Smart rotary nickel-titanium files to a master file 0.06 taper F3, root canal in the group 1 was obturated with warm vertical condensation using system B for downpack and Obtura II for backfilling without dental operating microscope; root canal in the group 2 was obturated using the same methods under the dental operating microscope. The effect of quality of root canal filling was evaluated by X-ray radiograph post-operatively and after two years of treatment. SPSS10.0 software package was used for Chi-square test.
Significant difference was found between the two groups on the quality of root canal filling post-operatively (P < 0.05),with better quality of root canal filling in the group using dental operating microscope, no significant difference was found between the two groups after two years (P > 0.05).
Warm vertical condensation under the dental operating microscope is a good method for root canal filling. It may improve the quality of root canal filling effectively, and therefore, worthy of clinical application.
Shanghai kou qiang yi xue = Shanghai journal of stomatology 02/2011; 20(1):97-100.
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ABSTRACT: To investigate the influence of stress on three-dimentional finite element models of maxillary first premolar with multifactors:cavities designs,restored materials,basing materials and loading sites.
Three dimensional finite element models for maxillary first premolar with different types cavity which were filled with different basing materials and restoration were constructed and the maximum main stress was measured according to factorial design.ANSYS9.0 software were employed,and the data was statistically analyzed with SPSS 13.0 software package for multivariate ANOVA.
Loading sites,cavity designs,restored materials and basing materials had effects on stress. Loading sites were the most important factors. Basing materials only had effect on occlusal stress. Cervix region was one of the stress concentration sites.
Loading site has significant influence on stress,cavity designs,restored materials must be considered during restorations. Supported by Key Research Project of Science and Technology Commission of Liaoning Province (Grant No. 99225008).
Shanghai kou qiang yi xue = Shanghai journal of stomatology 10/2009; 18(5):505-8.
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ABSTRACT: To evaluate the effect of Carisolv as chemical reagent on root canal cleanness in chemomechanical preparation.
Sixty extracted teeth which were dyed with methylene blue were randomly divided into 3 groups, different chemical reagents were applied in different groups. The optical density of methylene blue in irrigating solution were measured with UV-VIS spectrophotomer after preparation with each file, the root canal cleanness was evaluated under SEM. Two-way ANOVA and Kruskal-Wallis H test in SPSS 11.5 software package were used for statistical analysis.
There were significant differences in the optical density between the root canals treated with Carisolv and those with 2% tosylchloramide sodium plus 3% hydrogen peroxide (P<0.05), no significant difference was found in optical density between the root canals treated with Carisolv and those with 2.5% sodium hypochlorite (P>0.05). The results of SEM were consistent with those of the optical density of methylene blue.
As a chemical reagent, the cleaning ability of Carisolv was as effective as 2.5% sodium hypochlorite. Carisolv can remove the smear layer and debris, without causing excessive demineralization. Supported by Key Research Project of Science and Technology Committee of Liaoning Province(Grant No.00225001).
Shanghai kou qiang yi xue = Shanghai journal of stomatology 11/2008; 17(5):535-9.
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ABSTRACT: To investigate the effect of different composite resin, different light curing units, different irradiation time, different irradiation distance on cure depths of light curing composite resin.
Designed by factorial experiment, 192 Cylindrical samples were made with 4mm internal diameter and 6mm high mold. The whole samples were scanned by Planmeca ProMax panoramic X-ray unit, cure depths were measured using a scoping method described in the ISO standard for resin-based composites. The data was statistically analyzed by SPSS11.5 software package for ANOVA.
The differences of four factors-composite resin, light curing units, irradiation time, irradiation distance were significant (P<0.01), and the effects between-subjects were involved among four factors (P<0.01).
From this study, we conclude that cure depths may be affected by two kinds of light curing units, two kinds of composite resin, four kinds of irradiation time and four kinds of irradiation distances, once each factor is strengthened, cure depths could reach a more ideal effect. Supported by Key Research Project of Science and Technology Committee of Liaoning Province (Grant No.00225001).
Shanghai kou qiang yi xue = Shanghai journal of stomatology 10/2007; 16(5):520-2.
