There are differing opinions as to the extent to which root cementum has to be removed during root surface instrumentation over and above that of the debridement of plaque and calculus. Similarly, the amount of tooth material removed by individual instruments is also unclear, but a trend towards less damaging methods of root surface debridement has evolved in recent years. The purpose of this in vitro study was to determine the amounts of root substance removed by 4 different methods of instrumentation, hand curette, ultrasonic scaler, airscaler and fine grit diamond bur. Measurement of tooth substance loss was carried out with a specially constructed measuring device at 360 sites on 90 mandibular incisors following 12 working strokes with a clinically appropriate force of application. Only a thin layer of root substance (11.6 microns) was removed by the ultrasonic scaler, compared to the much greater losses sustained with the airscaler (93.5 microns), the curette (108.9 microns) and the diamond bur (118.7 microns).

In the present scanning electron microscopic study, the possibilities and limitations of non-surgical root planing were investigated. 10 single-rooted teeth from 4 patients with advanced periodontitis were studied. The root surfaces were cleaned and planed without flap reflection, using fine curettes. The teeth were then extracted and the root surfaces were systematically examined by scanning electron microscopy (SEM) for the presence of residual bacteria and calculus. 29 of 40 curetted root surfaces were free of residues, if they were reached by the curette. On the remaining 11 surfaces, only small amounts of plaque and minute islands of calculus were detected, primarily at the line angles and also in grooves and depressions in the root surfaces. Instrumentation to the base of the pocket was not achieved completely on 75% of the treated root surfaces, however. The primary reason for this was the extremely tortous pocket morphology on the teeth selected for study. In conclusion, it may be stated that during non-surgical root planing in cases of advanced periodontitis, surfaces that can be reached by curettes are usually free of plaque and calculus. However, in many cases the base of the pocket will not be reached. It is for this reason that deep periodontal pockets should be treated with direct vision, i.e., after the reflection of conservative flaps.

Vestibuloplasties with free gingival grafts were performed on 42 teeth in 12 patients exhibiting gingival recession. The tendency toward recurrence was studied after postoperative intervals of 1, 6 and 12 months. The extensions (vestibuloplasties), which were always wider than the transplant, recurred up to the transplantation margin. The transplant itself underwent shrinkage averaging 25 per cent. The vestibular depth, which had been increased by the operation, showed a 25 per cent reduction within 1 month, but then had a tendency to deepen again from 1 to 12 months postoperatively. The marginal free gingiva and sulcus depth were not influenced by the operation.

The Papilla Bleeding Index (PBI) was measured on 95 interdental papillae, after which the results were compared to Sulcus Bleeding Index (SBI) scores, sulcus fluid (SF) amounts and pocket depth (PD) measurements. In 52 of the papillae, a histological evaluation of the degree of inflammation was also made, in which not only the expanse of the infiltrate but also its intensity were of interest. The PBI was positively correlated with all of the other clinical indices. Obvious and highly statistically significant correlations were demonstrated among PBI, SBI and SF. In contrast, between PBI and PD, and between SBI and PD, only weak correlations were found. The comparison of the PBI with the histological determination of inflammation revealed a clear increase in the absolute amount of inflammatory infiltrate as PBI scores increased. In addition, there was a definitive shift in the intensity of the infiltration; moderate and severe areas of infiltration became more common as PBI scores went up.

The goal of the present study was to determine whether the clinical treatment results in terms of pocket probing depth reduction and attachment gain would be different following conventional periodontal flap surgery if, on the one hand, root surfaces were smoothed after plaque and calculus removal or, on the other hand, root surfaces were first thoroughly cleaned but then intentionally roughened. 13 adult patients with moderate periodontitis participated; the same patients acted as a unit of control. Evaluations were performed on a total of 224 sites on 81 anterior and premolar teeth. On the 41 test teeth (111 sites), a coarse diamond stone was used following traditional root planing to roughen the root surfaces. The 40 control teeth (113 sites) were cleaned and planed using Gracey curettes. Measurements performed 3 and 6 months post-surgery revealed significant reductions in probing depths at both "rough" and "smooth" sites. However, no differences between the 2 methods were detected. This was true also with regard to attachment gain. We conclude that striving for root surface smoothness during periodontal surgery appears unnecessary.