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951.
de Andrade e Silva SM Marquezini L Manso AP Garcia FP Carrilho MR Pashley DH Tay FR Carvalho RM 《The journal of adhesive dentistry》2007,9(6):505-512
PURPOSE: To test the effects of sequential application of potassium oxalate gel/adhesive agent on in vitro dentin permeability. MATERIALS AND METHODS: Full crown preparations were made in extracted human molars to expose deep coronal dentin. The roots and pulp were removed and the resulting crown segments were connected to a special device (Flodec) to permit the measurement of the permeability of the specimens before and after treatments. Minimum and maximum permeability were recorded after smear layer and phosphoric acid treatment. A new smear layer was created and the permeability measured after the crowns were bonded with Single Bond (3M ESPE), One-Up Bond F (Tokuyama), and AdheSE (Ivoclar Vivadent), either according to manufacturer's instructions or after treating the acid-etched dentin with a 3 wt% potassium oxalate gel. The results were expressed as a percentage of maximum permeability values. Impressions and epoxy resin replicas from the crown segments were produced for SEM examination. RESULTS: None of the adhesives were able to eliminate the fluid flow through dentin. Two-way ANOVA revealed that the application of potassium oxalate prior to the bonding procedures was the most effective technique in reducingthe dentin permeability (p < 0.05), regardless of the adhesive used. SEM micrographs showed that transudation of dentinal fluid could be identified on the surfaces of all replicas. CONCLUSION: The use of potassium oxalate gel was effective in reducing the permeability of bonded dentin. 相似文献
952.
Fregnani ER de Moraes Ramos FM Nadalin MR Silva-Sousa YT da Cruz Perez DE 《General dentistry》2007,55(2):129-131
Simple bone cysts are non-neoplastic bone lesions, classified as intraosseous pseudocysts without epithelial lining, that can be empty or filled by fluid and display uncommon clinical and radiographic features. This article presents an unusual case of a simple bone cyst with clinical and radiographic features similar to chronic apical periodontitis. A general dentist referred an 18-year-old man for endodontic treatment after the patient complained of pain in the mandibular right second molar, which displayed a significant bony radiolucency. Chronic periapical lesion was excluded after detailed clinical and radiographic examinations. During surgical exploration, an empty bone cavity was observed and curetted before wound closure. One year later, complete healing was observed. 相似文献
953.
Maior JR Da Figueira MA Netto AB de Souza FB da Silva CH Tredwin CJ 《Operative dentistry》2007,32(3):261-265
This study evaluated the importance of the union between dentin collagen and three different adhesive materials. Sixty Class V restorations were prepared on the buccal and lingual surfaces of 30 recently extracted human premolars, with the cervical margins in dentin and the occlusal margins in enamel. These restorations were distributed to three groups of 20 cavities each based on the employed adhesive system used: Group A: Single Bond; Group B: Prime&Bond NT; Group C: One Coat Bond. Each group was subdivided according to dentin treatment: (1) manufacturers' adhesive protocol and (2) removal of the collagens fibers (total etch + sodium hypochlorite 5% for two minutes) + adhesive protocol. After the restorations were completed, the teeth were stored in saline solution (24 hours/37 degrees C), subjected to thermal cycling, washing and scoring according to dye penetration. Dye penetration was evaluated, with the numbers ranging from 0 (no infiltration) to 3 (greatest infiltration). When the dentin microleakage scores were compared in subgroups A1XA2, B1XB2 and C1XC2, the Mann-Whitney Test revealed significant differences between groups B and C (p < 5%). The better results were shown in subgroups B2 (p = 0.0345) and C2 (p = 0.0029). The results showed that the collagen fibrils were not necessary for adhesion, and their removal positively influenced the marginal sealing of Prime&Bond NT and One Coat Bond. 相似文献
954.
Moreira da Silva E dos Santos GO Guimarães JG Barcellos Ade A Sampaio EM 《Operative dentistry》2007,32(4):356-362
This study analyzed the influence of C-factor, flexural modulus and viscous flow on gap formation in resin composite restorations. Two resin composites, a mini-filled hybrid (P 60) and a nanofilled (Supreme), were used. The flexural modulus was obtained from bar-shaped specimens submitted to three-point bending. Viscous flow was obtained from the difference between the initial and final diameter of resin composite disks submitted to a load of 10 N for 120 seconds. Gap analysis was conducted in three types of cylindrical cavities (C-factor of 1.8, 2.6 and 3.4) that were prepared on the occlusal surfaces of human molars. The gap width at the dentin-resin composite interface was measured using a 3D scanning system (Talyscan 150). The data were analyzed by ANOVA and Student-Newman-Keuls' test, t-test and linear regression analysis (alpha = 0.05). The cavities with C-factor 3.4 presented the highest Gap formation (p < 0.0001). The lowest Gap formation was found in cavities restored with Supreme resin composite (p < 0.0001). P 60 presented significantly higher flexural modulus and lower viscous flow than Supreme (p < 0.0001). Regression analyses detected a significant influence of flexural modulus and viscous flow on gap formation (p < 0.05). 相似文献
955.
956.
Pasternak Júnior B Teixeira CS Silva RG Vansan LP Sousa Neto MD 《Australian endodontic journal : the journal of the Australian Society of Endodontology Inc》2007,33(1):42-45
Variations in the dental anatomy are found in all teeth. Knowledge of these variations, particularly concerning the location and treatment of all canals, is very important for the success of the endodontic therapy. The purpose of this study is to present a clinical case of a maxillary second molar with three palatal canals, two mesio-buccal and one disto-buccal canal. This report serves to remind clinicians that such anatomical variations should be taken into account during endodontic treatment of the maxillary molars. 相似文献
957.
958.
da Silva CE da Silva ID Cerri A Weckx LL 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(4):497-500
Oncogenic human papillomaviruses (HPVs) are important agents in the genesis of gynecological cancer, and have also been implied in the genesis of oral cancer. With the purpose of evaluating the relationship between HPV and squamous cell carcinoma (SCC) of the tongue, a case-control study was performed. Fifty white male patients who were smokers and had the histological diagnosis of SCC of the tongue were selected. The control group was composed of 10 matched patients with no clinical evidence of tongue lesions. Polymerase chain reaction (PCR) was used to detect the presence of HPV genome in fresh-frozen tissue specimens from SCC of the tongue margin. Thirty-seven patients (74%) had a positive PCR for oncogenic papillomavirus, and only 1 specimen (10%) of the control group was positive for nononcogenic papillomavirus. Based on the statistical analysis of this study there was a 25.6% higher risk for SCC of the tongue to harbor oncogenic HPV than the healthy control tongue tissue. 相似文献
959.
OBJECTIVES: To evaluate the potential analytical interference of 24 drugs in the urinary protein. DESIGN AND METHODS: The analysis was done using Multistix 10SG and comparing the results of controls with urine samples supplemented with drugs. RESULTS: Positive interferences occurred with ciprofloxacin, quinine and chloroquine in supratherapeutical concentrations, while chloroquine interfered also in therapeutical concentration. CONCLUSIONS: False proteinuria in test-strips can lead to erroneous interpretations with repercussion in clinical procedures and higher costs to the health system. 相似文献
960.