In dental or oral treatment or surgery, a piece of absorbent cotton which consists of short fibers has been used for removing liquids in the oral cavity, such as saliva, etc., for providing a space required for surgery, or for clenching. For increased convenience, absorbent cotton cut to an appropriate size or pre-fabricated in a stick or roll form is also available.
When using absorbent cotton, however, it is necessary to cut it or wad it into a ball, either at the time of use or in advance. Although a cut piece of absorbent cotton adequately cleans the oral cavity, it is nappy and leaves short fibers in the oral cavity. It is also unsatisfactory for providing a space required for surgery (spacing effect) due to its form collapse by wetting. While absorbent cotton fabricated in a stick form using an adhesive may improve these aspects, since the adhesive used for prevention of surface napping and retention of the shape on absorption of water, such as carboxymethyl cellulose, is water-soluble, such an adhesive is dissolved in saliva, etc., upon use, releasing short fibers into the oral cavity and reducing the spacing effect.
In an attempt to prevent napping and releasing fibers in the oral cavity, there have been proposed a stick absorber in which absorbent cotton in a stick form is covered on approximately half its peripheral surface with a film sparingly permeable to moisture and is further spirally coiled with a fine yarn, as disclosed in Japanese Utility Model Publication No. 21178/84, and an absorbent material in which a mixture of cotton pulp and a highly absorbent powdery substance is wrapped with a water-permeable film, as disclosed in Japanese Utility Model Publication No. 7708/85. However, the former has the disadvantages that short fibers constituting the stick are easily released from the gaps between turns of the fine yarn, and that the complicated process required for coiling may result in a low productivity. Although the latter hardly leaves fibers in the oral cavity and has excellent form retention properties on water absorption, it also requires the complicated production process, and may result in a low productivity and high production cost. Moreover, when it is swollen with water or pressed when it contains water, the absorbent substance contained therein leaks out to cause discomfort to patients.