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

To enhance the plaque-inhibiting effect of chlorhexidine lozenges, a highly soluble form of chlorhexidine, such as the gluconate, should be used in place of C-HCI, and a less acidogenic carbohydrate should be sub- stituted for sucrose.

M. J. Barsby

EWEN S. J. and GWINNETT A. J. A scanning electron microscope study of teeth following periodontal instrumentation, J. Periodonto/. 48 (1977) 92-97.

A comparative electron microscopic study was made of the effect of sharp and dull hand curettes and ultrasonic tips used on root surfaces in I&O. It is claimed that major variations occurred depending upon the sharpness of the instrument and the number of strokes used.

A dull ultrasonic insert used with a denti- frice was claimed to produce a smooth, clean, ridge-free surface with little evidence of any instrument marks. Sharp hand curettes planed away more accretion and tissue than their dull counterparts, but what are called ‘frictional humps’ were observed. Sharp ultrasonic tips and a constant water flow produced a smoother surface than sharp hand curettes.

A. Brvan Wade

WAERHAUG J. Subgingival plaque and loss of attachment in periodontosis as evaluated on extracted teeth, J. Periodontol. 48 (1977) 125-130.

Twenty-four teeth removed from 16 patients whom the author considered to have perio- dontosis end who were in the age group of 12-22 years were stained with toludine blue before being examined by e stereo- microscope.

It was found that the subgingival plaque was in close relationship to the line of lost attachment, the author concluding that this showed that plaque was strongly involved in the destruction of the attachment appara tus. On some lingual and vestibular surfaces where plaque control had been good there was no subgingival plaque and no loss of attachment.

It was calculated that the rate of advance- ment of plaque was about 1-B mm per year and it is suggested that the lesion was the

combined effect of an extremely high in- vasiveness of some constituent of the plaque and some deficiency in the host’s defence mechanism. It is suggested that the lesion should be termed ‘destructive juvenile periodontitis’.

A. Bryan Wade

SAGLIE R. A scanning electron microscopic study of the relationship between the most apically located subgingival plaque and the epithelial attachment, J. Periodontol. 48 (1977) 105- 115.

In a scanning electron microscopic study of subgingival plaque in relation to the gingival epithelium of 12 teeth associated with chronic periodontitis, it was found that the plaque was usually covered by a surface coating, which was absent in the apical part.

The most apically located plaque displayed an organized structure which varied from tooth to tooth. Coccal forms were rarely found, but rod-like filamentous spiral and branching forms were present. Bacteria and spirochetes appeared to invade epithelial remnants on the tooth surface. Epithelium in direct contact with microorganisms showed widening of the intercellular spaces in a change in surface morphology.

A. Btvan Wade

BURGETT F. G., KNOWLES J. W., NISSLE R. R., SHICK R. A. and RAMFJORD S. P. Short term results of three modalities of periodontal treatment, J. Periodonto/. 48 (1977) 131-135.

In a group of 74 patients a comparison was made between subgingival curettage, pocket elimination surgery and the modified Widman flap procedure. Observations were made 4-6 weeks following completion of treatment.

Pocket elimination surgery included reverse bevel procedures with bone contouring and apical positioning or gingevectomy, whilst a modified Widman flap approach was con- sidered to be a reverse bevel flap procedure without intentional apical positioning and no bone contouring.