The purpose of the work was to determine the depth of penetration of the corrective silicone material into the gingival sulcus upon receipt of anatomical impressions. Studies were carried out on teeth prepared for cermet and metal-free dentures. Material and methods. The imprints were received in two different ways and materials no earlier than 7 days after preparation. Before measuring material penetration, the depth of gingival sulcus was identified at 4 points around each tooth. We obtained the measurement of 120 anatomical imprints. Initially, one-stage two-layer impression with a shoulder and with a previous retraction of the gums (first method), then one-stage double-layer imprint without a shoulder and without retraction (2 methods), a two-stage two-layer with a shiolder and with previous gums retraction (3 methods) and the next two-stage two-layered without a shoulder with retraction of gums (4 methods). Depth of gingival sulcus measured graded periodontal probe with a cost of 0.5 mm divisions at 4 points around each tooth. Depths of the sulcus were measured from the final line of preparation to the bottom of the sulcus from the vestibular-medial, vestibulo-distal, oral-medial and oral-distal surfaces of the crown of the tooth. Results and discussion. The results of the measurements were input into the protocols of research. After removing the impressions from the oral cavity, they were rinsed under running water and disinfectant solution of 2% glutaraldehyde, and then the repellent material was carefully separated from the spoon. In order to calculate the depth of penetration of the corrective material in the gingival sulcus, the cuttings of the impressions were made at the places of preliminary measurement of the depth of the groove, which were then studied under a microscope L3002 (Granum, Ukraine) at 4x magnification. The results of the study showed a different degrees of penetration of corrective material in the gingival sulcus, depending on the method of obtaining the impression. Measurement of the tooth-spindle groove in mm showed that on average the best material penetrated into the groove during the second method of obtaining an anatomical imprint at 0.49 ± 0.015 mm. The minimum penetration was noted in the third method (one-stage two-layer imprints without a ledge and without retraction of the gums) 39.2 ± 2.24%. The penetration of the corrective material upon obtaining a two-stage, two-layer impressions with a shoulder and retraction (threads «Gingi-Pak, USA») was significantly higher than any of the four methods of receiving imprints. In comparison with the first method, the material penetrated deeper into 17.2% (p <0.05), with the second and third methods it was by 22.3% (p <0.05) and 15.6% (p <0.05), respectively. Conclusion. The study pointed out that upon receipt of anatomical impressions, silicone impression material fills from 36.1 ± 2.17% to 66.8 ± 2.14% of the total depth of the gingival sulcus. Two-stage method of obtaining the impression showed the best results of material penetration into the gingival sulcus and ranged from 43.6 ± 2.07% to 66.8 ± 2.14%. We also revealed that the presence of a shoulder influenced the penetration depth of the correction material into the gingival sulcus.
Keywords: orthopedic dentistry, impression materials, gingival sulcus, two-stage impression technique, sulcus filling
Full text: PDF (Ukr) 348K