Repeated measurements of attachment level appear to be important assessments in periodontal clinical trials, yet the lack of reliability for this assessment creates measurement error which in turn demands increased sample sizes or reduces the power of the test. A plastic occlusal stent has been developed as a fixed reference point to assess changes in probing depths over time and thus reflect differences in attachment levels. The advantages of this system over traditional methods have not been measured. The purpose of this study was to determine intra- and interexaminer reliability for probing depths from the stent and the CEJ. Paired measurements of attachment level using the stent produced correlation coefficients for inter- and intraexaminer readings of 0.84 and 0.76, respectively. For subgingival cementoenamel (CEJ) measurements, lower coefficients of 0.71 and 0.59 were found for inter- and intraexaminer paired readings, respectively. Thus, measurements using the stent appear to be more reliable than subgingival CEJ readings.

Several studies have indicated that the combination of metronidazole and spiramycin is synergistic against anaerobic bacteria and may be effective against oral infections. The present study sought to determine the efficacy and safety of a commercial preparation of these two antibiotics (Rodogyl) when used adjunctively in the treatment of advanced periodontal disease. In a double-blind parallel randomized trial, 56 patients (mean age = 44 years) with advanced periodontitis (50 of whom completed the study) were assigned to either the Rodogyl or placebo group. Both groups were thoroughly scaled and root planned for approximately 6 hours, with one group receiving Rodogyl for 2 weeks and the other a placebo. No other therapy was received during the study period. Two sites in each patient with probing depths of at least 7 mm were selected for study. Plaque level (P1I), gingival inflammation (GI), probing depth (PD), and attachment level (AL) were measured at baseline, 14 days, 1 month, and then at monthly intervals up to 6 months. Subgingival bacteria were monitored with dark-field microscopy. The development of resistant bacteria, as well as side effects to the medications, was also monitored. The Rodogyl group exhibited a greater gain in AL (0.67 mm) from the 2-month interval until the end of the study. Although this difference was statistically significant (P less than 0.05), it was not necessarily of biologic significance. There was a significantly greater decline in the proportion of spirochetes in the Rodogyl group at the 14-day interval, and this difference remained significant (P less than 0.05) at all study intervals. No difference in the proportion of motile organisms was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Dark‐field microscopy to monitor subgingival bacteria has been advocated as an accepted adjunct in monitoring periodontal disease. By aging two flagella stains (Gray's and Ryu's) for at least 3 wk at room temperature, we were able to stain four morphological groups, spirochetes, motile rods, coccoids and “other types” which have been suggested as indicator organisms of periodontal destruction. The relative proportions of these groups present in plaque samples from 17 clinically diseased sites were compared using dark‐field microscopy and the two staining methods. All three techniques gave similar proportions of spirochetes. However, the staining methods revealed significantly more flagellated cells than motile cells seen with dark‐field microscopy. Advantages of the staining method over dark‐field microscopy include the convenience of examining plaque samples at a later time and the availability of a permanent record.