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.

Consensus has not been reached on the desired characteristics of the root surface following cleaning. It is also not clear what degree of roughness or smoothness results from use of different instruments. In the present human clinical study, various instruments for root surface cleaning were evaluated. 18 teeth destined for extraction for periodontal reasons were utilized. After reflection of soft tissue flaps, the 72 root surface aspects of the 18 teeth were uniformally treated with one of the following instruments: Gracey curette (GC), piezo ultrasonic scaler (PUS), Perioplaner curette (PPC), sonic scaler (SS), 75 microns diamond (75 D) and 15 microns diamond (15.D). The degree of roughness of each surface was measured after extraction. A planimetry apparatus was used to establish the average surface roughness (Ra) and the mean depth of the roughness profile (Rz). It was demonstrated that hand- and machine-driven curettes as well as very fine rotating diamonds created the smoothest root surfaces, while "vibrating" instruments such as sonic and ultrasonic scalers, as well as coarse diamonds, tended to roughen the root surface. Whether the root surface should be rough or smooth in order to enhance tissue healing remains an open question.

The goal of the present in vivo study was to evaluate human roots by means of scanning electron microscopy (SEM), after treating the root surfaces either with conventional hand instruments or with newly developed diamond burs. Peculiar root anatomy often makes perfect instrumentation with hand instruments difficult or impossible. On 20 teeth destined for extraction because of severe periodontitis, the root surfaces were exposed by mucoperiosteal flap procedures. Ten roots were then planed using fine curettes, and 10 were instrumented using diamond burs. Following extraction, the root surfaces were stained and photographed. Stained areas were examined by SEM. On the 20 test teeth, 79 surfaces were evaluated. From these, 381 stained zones were checked by SEM for the presence of bacteria. A total of 216 stained areas from teeth treated by hand instruments was evaluated; 15 of these (6.9%) contained bacteria. Of roots treated by diamond burs, 165 stained areas were evaluated; 9 (5.5%) exhibited bacteria. Thus, both methods resulted in root surfaces that were essentially bacteria-free.

This study was designed to ascertain whether conservative cleaning of surgically-exposed root surfaces can achieve complete plaque removal. 10 single-rooted teeth (40 surfaces) from 4 patients with advanced periodontitis were included in the study. After flap reflection, the root surfaces were cleaned using only rubber cups, EVA plastic tips and prophy paste. No attempt was made to remove calculus. Immediately after treatment, the teeth were extracted. Then root surfaces were systematically examined in the scanning electron microscope to detect any residual bacteria (plaque). 27 of the 40 treated root surfaces were plaque-free. On the other 13 root surfaces, only a few isolated small islands of plaque were detected. On the other hand, relatively extensive areas of the root surfaces exhibited calculus. Bacterial plaque accumulation was routinely observed on the rough calculus surfaces and at the periphery of the hard deposits. These results demonstrate that the instruments used in this study can successfully remove plaque from exposed root surfaces. However, subgingival calculus that is firmly attached to root surfaces virtually always harbors plaque bacteria; such deposits require more aggressive instrumentation (scalers, curettes) for removal.