362 Journal of Dentistry, Vol. ~/NO. 4

connective tissue were placed on recipient beds in the non-keratinized alveolar mucosa of rhesus monkeys. After 4 weeks the grafts resembled keratinized gingiva clini- cally and this observation was confirmed histologically. Electron microscopic exami- nation showed that the supporting connective tissue and changes in the crevicular epithelium made the graft tissue identical with keratinized gingival tissue in the 4-week specimens. It is therefore concluded that crevicular epithelium has the potential to keratinize but that this is prevented by inflammation in the underlying connective tissue.

A. Bryan Wade

WALSH T. F. and WAITE I. M. A comparison of postsurgical healing follow- ing ddbridement by ultrasonic or hand instruments,J. Periodonrol. 49 (1978) 201- 205.

Root debridement at the time of periodontal flap surgery was undertaken on one side of the mouth using an ultrasonic scaler and on the other side with hand instruments. Healing was evaluated over a period of 3 weeks using the Gingival Index, crevicular fluid measurements and the Plaque and Retention Indices. It was found that healing was more rapid as evaluated by the Gingival Index and crevicular fluid when ultrasonic debridement had been used, but no differ- ence was registered in the Plaque or Retention Index. Postoperative pain appear- ed to be the same with both techniques.

A. Bryan Wade

GOASLINO G. D., ROBERTSON 8. B., MAHAN C. J., MORRISON W. W. and OLSON J. V. Thickness of facial gingiva, J. Periodonfol. 48 (1977) 768-771.

A device to measure the thickness of the gingiva is described. A probe is used to penetrate the gingival tissue, both to the tooth surface and to the bone of the alveolar process and, utilizing a differential trans- former coupled to an oscillator and digital voltmeter, the distance of penetration is determined.

This was undertaken on the facial aspect of certain maxillary and mandibular teeth, penetration being made at the depth of the gingival crevice and midway between this point and the mucogingival junction.

It was found that the probe assembly was accurate to 0.01 mm and that the average range of differences in reproducibility tests never exceeded 0.15 mm. Free gingival thickness averaged 1.56 f 0.39 mm and the thickness of the attached gingiva was 1.25 f 0.42 mm, the total mean thickness for all areas being 1.41 mm. Thickness of the mandibular free and attached gingiva and the maxillary free gingiva increased as measurements were made in a posterior direction, whereas thickness of the maxillary attached gingiva remained fairly constant.

The thickness measured at the depth of a crevice was directly ,proportional to the width of the free gingiva. Thickness measur- ed midway between the depth of the crevice and the mucogingival junction was inversely proportional to the width of the attached gingiva.

A. Bryan Wade

MORMANN W. and CIANCIO S. G. Blood supply of human gingiva following periodontol surgery.’ A fluorescein angio- graphic study, J. Periodontol. 48 (1977) 681-692.

A method of studying the gingival vascula- ture following the intravenous injection of sodium fluorescein is described. Different types of flaps were constructed in various individuals and photographed at intervals from 24 hours to 7 days.

As a result it is recommended that flaps should be broad enough at their base to include major gingival vessels, that the length of a flap should not exceed its width by the ratio of 2 : 1 and that minimal tension should be reduced by suturing techniques, the tissue being managed gently during the surgical procedure. Partial thickness flap prepara- tions to cover avascular sites should not be too thin so that sufficient blood vessels are included in them. The apical portion of periodontal flaps should be full thickness whenever possible.

A. Bryan Wade