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Biomedical subjects

I Sewerin

Publications and source records attributed to I Sewerin.

At least 73 records · Page 4Linked to original sources
PubMed1981

Frequency and distribution of proximal overlappings on posterior bitewing radiographs.

4374 proximal surfaces on 791 posterior bitewing radiographs were classified according to overlappings. Six categories were used: 1) no overlapping, 2) blurred contact areas, 3) less than half of the enamel overlapped, 4) more than half of the enamel overlapped, 5) dentin overlapped, and 6) unclassifiable overlappings. Filled surfaces and surfaces not in contact were excluded. Only 19% of the surfaces did not have overlappings 65% exhibited mild overlappings (categories 2 and 3), and 16% severe overlappings (categories 4, 5 and 6). The frequencies of no overlappings varied from 7% to 40% for single tooth surfaces. The relationship between distribution of overlappings and tooth surfaces was statistically significant at the 0.05% level. Principles of excluding overlapping surfaces have been inconsistent in previous epidemiologic studies and clinical trials. The use of exact criteria for exclusion is recommended.

Adolescent↗
PubMed1981

Influence of X-ray beam angulation upon the radiographic image of proximal carious lesions.

Twenty-two extracted human molars and premolars with a total of 34 initial proximal carious lesions were radiographed in 16 different views varying the horizontal angulation of the X-ray beam in steps of 2.5 degrees. The radiographs were read simultaneously by three observers. Clinical and radiographic diagnoses were compared. When utilizing all 16 views the concordance was 95%. All proximal surfaces were scored using four scoring classes. Surfaces without radiolucencies were scored 0, and carious surfaces were scored according to the extent of the radiolucencies. Nine sound and 12 carious surfaces were assigned identical scores in all 16 views, while 22 (65%) of the carious surfaces were assigned two, three or four different scores. Deviations from a direction of the X-ray beam tangential to the proximal surface eliciting a radiographic image belonging to a different score were measured. In 71% of the cases a deviation of 7.5 degrees or less elicited a different score. Projectional circumstances should be taken into consideration in interpreting proximal radiolucencies.

Dental Caries↗
PubMed1981

Influence of spatulation time upon the radiographic homogeneity of Adaptic Radiopaque fillings.

1)Twelve test cavities were filled with Adaptic Radiopaque by the author, varying the spatulation times form 5 s to 60 s at 5-s intervals but using the same mixing technique. Fillings spatulated for less than 20 s appeared inhomogeneous on radiograph. 2)Twenty-eight dentists produced 84 test fillings determining themselves their spatulation time and applying their own mixing technique. Spatulation times varied from 10 to 55 s. The fillings were radiographed under standardized conditions. Twenty-five were classified as radiographically homogeneous, 35 as partly inhomogeneous, and 24 as inhomogeneous. Short spatulation times were correlated with a high frequency of inhomogeneous fillings. Only 15% of fillings spatulated for less than 30 s were radiographically homogeneous. The observed inhomogeneities imply a risk of false positive diagnoses of secondary carious lesions.

Chemical Phenomena↗