• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.46-55
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• 2000

During bonding procedure of composite resin, the prepared cavity can be contaminated by saliva. In this study, marginal microleakage and shear bond strength of a composite resin to primed enamel and dentin treated with artificial saliva(Taliva$^{(R)}$) were evaluated. For the marginal microleakage test, Class V cavities were prepared in the buccal surfaces of fifty molars. The samples were randomly assigned into 5 groups with 10 samples in each group. Control group was applied with a bonding system (Scotchbond$^{TM}$ Multi-Purpose plus) according to manufacture's directions without saliva contamination. Experimental groups were divided into 4 groups and contaminated with artificial saliva for 30 seconds after priming: Experimental 1 group ; artificial saliva was dried with compressed air only, Experimental 2 group ; artificial saliva was rinsed and dried. Experimental 3 group ; cavities were etched with 35% phosphoric acid for 15 seconds after rinsing and drying artificial saliva. Experimental 4 group ; cavities were etched with 35% phosphoric acid for 15 seconds and primer was reapplied after rinsing and drying artificial saliva. All the cavities were applied a bonding agent and filled with a composite resin (Z-100$^{TM}$). Specimens were immersed in 0.5% basic fuschin dye for 24 hours and embedded in transparent acrylic resin and sectioned buccolingually with diamond wheel saw. Four sections were obtained from one specimen. Degree of marginal leakage was scored under stereomicroscope and their scores were averaged from four sections. The data were analyzed by Kruscal-Wallis test and Fisher's LSD. For the shear bond strength test, the buccal or occlusal surfaces of one hundred molar teeth were ground to expose enamel(n=50) or dentin(n=50) using diamond wheel saw and its surface was smoothed with Lapping and Polishing Machine(South Bay Technology Co., U.S.A.). Samples were divided into 5 groups. Treatment of saliva-contaminated enamel and dentin surfaces was same as the marginal microleakage test and composite resin was bonded via a gelatin capsule. All specimens were stored in distilled water for 48 hours. The shear bond strengths were measured by universal testing machine (AGS-1000 4D, Shimaduzu Co., Japan) with a crosshead speed of 5 mm/minute. Failure mode of fracture sites was examined under stereomicroscope. The data were analyzed by ANOVA and Tukey's studentized range test. The results of this study were as follows : 1. Enamel marginal microleakage showed no significant difference among groups. 2. Dentinal marginal microleakages of control, experimental 2 and 4 groups were lower than those of experimental 1 and 3 groups (p<0.05). 3. The shear bond strength to enamel was the highest value in control group (20.03${\pm}$4.47MPa) and the lowest value in experimental 1 group (13.28${\pm}$6.52MPa). There were significant differences between experimental 1 group and other groups (p<0.05). 4. The shear bond strength to dentin was higher in control group (17.87${\pm}$4.02MPa) and experimental 4 group (16.38${\pm}$3.23MPa) than in other groups, its value was low in experimental 1 group (3.95${\pm}$2.51 MPa) and experimental 2 group (6.72${\pm}$2.26MPa)(p<0.05). 5. Failure mode of fractured site on the enamel showed mostly adhesive failures in experimental 1 and 3 groups. 6. Failure mode of fractured site on the dentin did not show adhesive failures in control group, but showed mostly adhesive failure in experimental groups. As a summary of above results, if the primed tooth surface was contaminated with artificial saliva, primer should be reapplied after re-etching it.

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.500-518
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• 1996

Background : The solitary pulmonary nodule(SPN) presents a diagnostic dilemma to the physician and the patient. Many clinical characteristics(i.e. age, smoking history, prior history of malignancy) and radiological characteristics( i.e. size, calcification, growth rate, several findings of computed tomography) have been proposed to help to determine whether the SPN was benign or malignant. However, most of these diagnostic guidelines are based on the data collected before computed tomography(CT) has been introduced and lung cancer was not as common as these days. Moreover, it is not well established whether these guidelines from western populations could be applicable to Korean patients. Methods : We had a retrospective analysis of the case records and radiographic findings in 114 patients presenting with SPN from Jan. 1994 to Feb. 1995 in Seoul National University Hospital, a tertiary referral hospital. Results : We observed the following results ; (1) Out of 113 SPNs, the etiology was documented in 94 SP IS. There were 34 benign SP s and 60 malignant SPNs. Among which, 49 SPNs were primary lung cancers and the most common hi stologic type was adenocarcinoma. (2) The average age of patients with benign and malignant SPNs was $49.7{\pm}12.0$ and $58.1{\pm}10.0$ years, respectively( p=0.0004), and the malignant SPNs had a striking linear propensity to increase with age. (3) No significant difference in the hi story of smoking was noted between the patients with benign SPNs($13.0{\pm}17.6$ pack- year) and those with malignant SPNs($18.6{\pm}25.1$ pack-year) (p=0.2108). (4) 9 out of 10 patients with prior history of malignancy had malignant SPNs. 5 were new primary lung cancers with no relation to prior malignancy. (5) The average size of benign SPNs($3.01{\pm}1.20cm$) and malignant SPNs($2.98{\pm}0.97cm$) was not significantly different(p=0.8937). (6) The volume doubling time could be calculated in 22 SPNs. 9 SPNs had the volume doubling time longer than 400 days. Out of these, 6 were malignant SPNs. (7) The CT findings suggesting malignancy included the lobulated or spiculated border, air- bronchogram, pleural tail, and lymphadenopathy. In contrast, calcification, central low attenuation, cavity with even thickness, well-marginated border, and peri nodular micronodules were more suggestive for benign nodule. (8) The diagnostic yield of percutaneous needle aspiration and biopsy was 57.6%(19/33) of benign SPNs and 81.0%(47/58) of malignant SPNs. The diagnostic value of sputum analysis and bronchoscopic evaluations were relatively very low. (9) 42.3%(11/26) of SPNs of undetermined etiology preoperatively turned out to be malignant after surgical resection. Overall, 75.4%(46/61) of surgically resected SPNs were malignant. Conclusions : We conclude that the likelihood of malignant SPN correlates the age of patient, prior history of malignancy, some CT findings including lobulated or spiculated border, air-bronchogram, pleural tail and lymphadenopathy. However, the history of smoking, the size of the nodule, and the volume doubling time are not helpful to determent whether the SPN is benign or malignant, which have been regarded as valuable clinical parameters previously. We suggest that aggressive diagnostic approach including surgical resection is necessary in patient with SPNs.