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Biomedical subjects

D A Orkin

Publications and source records attributed to D A Orkin.

7 recordsLinked to original sources
PubMed1990

Comparative study of the retentive strengths of dowels of three different diameters in combination with one or two different-sized threaded pins.

Vented parallel-sided, serrated posts cemented into matching precision channels provide excellent retentive strength; however, they do not offer significant resistance to rotational forces. This article explores the effectiveness of using supplementary pins to compensate for this deficiency. A standardized method was used to place combinations of parallel-sided posts and screw-type pins in prepared root canals of extracted human teeth. Standardized composite resin cores were made for the posts. Results indicate that the dentist must take note of the amount of dentin available for pin placement and, with reference to the provided graphs, determine the ideal size and number of pin(s) to be inserted.

Analysis of Variance↗
PubMed1987

The relationship of the position of crown margins to gingival health.

A survey was conducted of 423 crown margins that were divided into 355 subgingival margins and 68 supragingival margins. The plaque index, gingival bleeding, and recession surrounding the artificial crown were recorded and compared to the unprepared contralateral tooth. Gingival tissues tended to bleed 2.42 times more frequently with subgingival margins and have a 2.65 times higher chance of gingival recession. Crowns with supragingival margins did not differ significantly compared with the contralateral tooth, but crowns with subgingival margins had greater bleeding and recession compared with the contralateral tooth. It is recommended that supragingival margins become standard clinical procedures when feasible. A further analysis will be instituted to determine whether different crown materials affect the gingivae.

Adult↗