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The amalgam margin angle, marginal breakdown and adjacent caries in occlusal enamel, a pilot study on extracted teeth
Author(s) -
GRAJOWER R.,
NOVICKAS D.
Publication year - 1988
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1111/j.1365-2842.1988.tb00155.x
Subject(s) - amalgam (chemistry) , enamel paint , dentistry , gingival margin , margin (machine learning) , orthodontics , medicine , chemistry , electrode , machine learning , computer science
Summary The object of this study was to determine for amalgam restorations the relationship between marginal breakdown and (i) over‐ or undercarving; (ii) the amalgam margin angle (AMA); and (iii) the incidence of carious occlusal enamel adjacent to the restoration. Fifty‐two extracted human teeth with occlusal amalgam fillings from the Chicago (C) area and forty‐three teeth from the Jerusalem (J) area, were examined with a probe. Employing common clinical criteria, it was found that replacement of the fillings was indicated due to extensive marginal defects, in 45% of the C teeth, and 41% of the J teeth. The occlusal amalgam margins and the incidence of caries adjacent to these margins were studied on facio‐lingual sections. The incidence and the average AMA values for six margin types were measured on random sections and were found to be: all margins (100%, 67°); intact flush margins (31%, 69°); fractured flush margins (21%, 56°); undercarved margins which fractured (22%, 74°), or did not fracture (9%, 80°) near the cavity margin; margins with amalgam deficiencies (12%, 62°); and margins with separation between enamel and amalgam by remnants of linings (5%). Marginal breakdown was found in 42% of the margins and was associated mainly with flush carving at low AM As, and with broken flashes resulting from undercarving. Occlusal carious enamel was detected on 19% of the J teeth and none of the C teeth. Sixty‐three per cent of these lesions were associated with fractured undercarved margins.