The maxillary one-sided removable partial denture.
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Biomedical subjects
Publications and source records attributed to H Baharav.
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This study compared the dimensional accuracy of impressions and dies made from a metal model simulating prepared abutments and having gingival sulci of varying widths. Measurements of the abutments, impressions, and stone dies were made using a travelling microscope, and the number of defects in each impression was recorded. The impressions and dies made from abutments with narrower sulci showed greater distortions. Analysis of variance and the Fisher PLSD post hoc test indicated significant differences between the group having a sulcular width of 0.08 mm and the groups having larger sulcular widths for the impressions and for the dies (P < .05). The large coefficient of variation occurring groups having 0.08-, 0.13-, and 0.18-mm sulcular widths demonstrated the difficulty of consistently obtaining good impressions of abutments having such narrow sulcular widths. Between 50% and 90% of abutment impressions having sulcular widths of 0.08 and 0.13 mm had defects.
The authors investigated the length of time medicated displacement cord should remain in the gingival crevice prior to impression making. A silk cord (Deknatel) was placed into the sulcus and was not removed during the study. Medicated cords (Hemodent on Ultrapak #1) were placed into the gingival sulcus for 2, 4, 6, and 8 minutes. Following cord removal, closure of the sulcus was recorded at intervals using a miniature video camera. Crevicular widths were measured at the midbuccal and transitional line angle areas. At both the midbuccal and transitional line angle areas, gingival crevices displaced for 2 minutes were significantly smaller at 20 seconds (P < .05) than crevices following displacement for 4, 6, and 8 minutes. No significant difference in crevicular width was found at any time period after cord removal for crevices displaced for 4, 6, and 8 minutes. At the transitional line angle, crevicular widths were significantly smaller than at the midbuccal at 20 seconds for all times and remained so up to 180 seconds. To achieve a crevicular width of 0.2 mm, cord should remain in the gingival crevice for an optimum time of 4 minutes prior to impression making when using the materials evaluated in this study.