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Biomedical subjects

M L Canales

Publications and source records attributed to M L Canales.

10 recordsLinked to original sources
PubMed1993

Kissing balloon technique in complex PTCA: single guiding catheter and dual wire rapid exchange system.

This report is a description, based on four cases, of a variation from previously described approaches for accomplishing the "kissing balloon" technique for complex PTCA. We describe a case in which a single guiding catheter is utilized in combination with two over-the-wire monorail type balloon catheters allowing use of standard length (175 cm) guidewires. Various combinations of balloon diameters are described. We believe this approach has significant advantages over other techniques, principally in its rapid and easy usage.

Angioplasty, Balloon, Coronary↗
PubMed1990

Histological differences between teeth with adult periodontitis and prepubertal periodontitis.

Thirty-nine permanent teeth from three siblings aged 11 to 14 years were extracted because of generalized prepubertal periodontitis (PP) and studied histologically with light microscopy. Twenty healthy teeth (HT) removed for orthodontic procedures from 10 children of similar ages and 22 teeth affected by adult periodontitis (AP) extracted from patients over 50 years old were used as controls. The cementum of the PP teeth was much thicker than that of the healthy teeth. A high percentage of resorption, unrelated to inflammation, was found in all the teeth studied. In 24 PP teeth the cementum was infiltrated by microorganisms and bacterial substances. All PP teeth showed a cuticle ranging from 10 to 80 microns in thickness on the diseased cementum. No similar structure was noted on the diseased cementum of the AP teeth. The PP teeth did not show any structural changes which could account for the severity of the periodontal lesions.

Adolescent↗
PubMed1990

Morphologic and histochemical characteristics of the dental cuticle in teeth affected by prepubertal periodontitis.

A study was undertaken to determine the nature and composition of the cuticle found in teeth with generalized prepubertal periodontitis (PP). This was accomplished by using histological and histochemical methods on decalcified specimens. Forty-six permanent teeth which were extracted from three prepubertal periodontitis patients (siblings) were used. Nineteen of the 46 teeth were obtained with the facial or interdental gingiva. As a control, 20 healthy teeth extracted from 10 children for orthodontics reasons, and 22 teeth affected by terminal adult periodontitis (AP), were used. All the teeth with PP showed a thick coat covering the root surface from the cemento-enamel junction to the junctional epithelium. In some teeth the cuticle extended a few microns coronally to the cemento-enamel junction. The cuticle had a thickness which varied between 10 to 80 microns. It usually presented a very regular surface in the coronal portion of the root, and showed laminations suggesting appositional growth. In the middle and apical portions of the root exposed to the pocket, the cuticle was lobular with a very irregular surface and was covered with a thick microbial plaque. The staining reactions indicated that the cuticle was made of proteins probably derived from the inflammatory exudate. None of the healthy teeth examined nor those affected by AP showed a cuticle similar to those with PP. The cuticle formed on the teeth with PP appears to be an abnormal structure of proteinaceous nature, characteristic of these teeth, and may possibly play a role in the pathogenesis of the disease.

Adolescent↗
PubMed1989

Temperature changes in thermoplasticized gutta-percha: a comparison of two ultrasonic units.

With the use of an extracted human tooth as in vitro model, this study measured temperature changes in the surface of gutta-percha while it was being ultrasonically thermoplasticized. Two sources of ultrasonic oscillation were used: a Cavitron 2001 ultrasonic unit with a file in a PR-30 insert and an ENAC ultrasonic unit with a plugger or file. Temperature elevation in the apical third of the tooth was minimal with either instrument (1.66 degrees C to 3.74 degrees C). The temperature rise in the middle third was higher with the ENAC unit, although probably still within clinically acceptable limits (range, 6.35 degrees C to 19.10 degrees C). The time taken for each unit to thermoplasticize the gutta-percha and reach a predetermined distance in the experimental model was recorded and defined as instrument efficiency. The Cavitron unit that had the PR-30 insert with a No. 25 file required 0.48 sec/mm, whereas the ENAC unit with a No. 25 file required 10.83 sec/mm and the ENAC unit with a plugger required 8.38 sec/mm. It appears that the Cavitron unit with a PR-30 insert was more than 22 times as efficient as the ENAC unit for thermoplasticizing gutta-percha under the experimental conditions used in this study.

Chemical Phenomena↗
PubMed1986

Temporary replacement of missing maxillary incisors.

A technique has been described in which a polycarbonate crown form was used as a temporary replacement for a missing central incisor. As with the other techniques of temporary replacement using acid etching, little chair time is required for the procedure. Additional advantages of this technique are that polycarbonate crown forms are inexpensive and readily available in most dental offices, and filling the crown form with composite resin and opening up the embrasures allows maximum bulk of resin at the connector surface without encountering the staining problems associated with composite resin pontics.

Acid Etching, Dental↗