The development and clinical use of acrylic strips containing anti-microbial agents in the management of chronic periodontitis.

Several methods have been used to deliver antimicrobial drugs into periodontal pockets. This study was concerned with the development of acrylic in strip form for such an application. Initially the release of chlorhexidine acetate from cold cured acrylic strips into water, was measured spectrophotometrically over a 15 day period. The release of chlorhexidine was highest on day 1, was reduced considerably by day 2 and then fell progressively to day 15. With the exception of the release on day 1 there was little difference in daily release from drug admixtures between 40 to 80 per cent. Comparison of the release of chlorhexidine, metronidazole and tetracycline demonstrated a similar release pattern for metronidazole and chlorhexidine but the daily release of tetracycline was considerably less. A bioassay indicated that all drugs were released in active form. In a clinical study chlorhexidine, tetracycline and metronidazole rods were placed in periodontal pockets for 2-3 days and the effects monitored by dark field microscopy. All drugs produced a proportional increase in cocci and marked reductions in other organisms, notably the curved and motile rods and spirochaetes. The effects of metronidazole and tetracycline were greater than those of chlorhexidine. A second clinical study compared the effects of metronidazole and tetracycline strips placed for 2 weeks. Clinically, both treatment methods had immediate effects upon pocketing, bleeding on probing and crevicular flow, which for metronidazole were maintained to the 3-month follow-up period. For tetracycline, the bleeding and crevicular flow were significantly reduced and maintained to the 3-month period but the initial pocket reduction returned to baseline levels by 3 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the immediate effects on the sub-gingival microflora of acrylic strips containing 40% chlorhexidine, metronidazole or tetracycline.

In the management of chronic periodontitis, there has been a renewed interest in the local delivery of antimicrobial drugs into periodontal pockets. This study assessed the effects of the acrylic strip delivery system containing chlorhexidine, metronidazole or tetracycline on subgingival microflora assessed by dark field microscopy. Strips containing 40% chlorhexidine, metronidazole or tetracycline were placed for 2 to 3 days into pockets greater than 6 mm which bled on probing. Plaque samples were obtained before and after treatment and counts of morphological and motile groups of organisms were made by dark field microscopy. Prior to treatment, the dark field microscopic counts were similar to those previously reported for diseased sites with motile bacteria, in particular spirochaetes, present in high numbers. Following treatment, all 3 antimicrobial drugs produced a significant increase in the proportion of cocci and significant decreases in all other types of organisms. Motile organisms, in particular, were markedly reduced and spirochaetes could not be recovered from some sites treated with metronidazole and tetracycline. Metronidazole was significantly more effective than tetracycline or chlorhexidine on spirochaetes. The results indicate that acrylic strips may be useful in the management of chronic periodontitis as an adjunct to routine mechanical methods.