Adjunctive treatment with subantimicrobial doses of doxycycline: effects on gingival fluid collagenase activity and attachment loss in adult periodontitis.

OBJECTIVES: The therapeutic effects of doxycycline and other tetracyclines in the treatment of periodontitis involve, at least in part, mechanisms that are unrelated to their antimicrobial activity. Previous clinical studies have shown that doxycycline administered orally, at doses below those needed for antimicrobial efficacy, to human subjects with adult periodontitis resulted in significantly reduced collagenase activity in gingival crevicular fluid (GCF) and in extracts of inflamed gingival tissues. The purpose of the present study was to identify clinically effective dosing regimens using subantimicrobial dose doxycycline (SDD) as an adjunctive therapy in patients with adult periodontitis. MATERIAL AND METHODS: A total of 75 adult men and women qualified for enrollment into the three-part, placebo-controlled, double-blind, parallel-group study. Patients were stratified based on repeatedly exhibiting pathologic levels of periodontal attachment (ALv) and GCF collagenase activity at several appointments prior to baseline. Patients were administered a scaling and prophylaxis, then 1 of 5 treatment schedules for 12 weeks (part I), followed by a 12-week period of no drug therapy (part II), a second scaling and prophylaxis, and 12 additional weeks of treatment (part III). Primary determinants of efficacy included reductions in GCF collagenase activity and changes in relative ALv. RESULTS: 66 patients completed the 1st 12 weeks (part I) of the 3-part, 36-week study; 51 patients completed the entire 36-week study. From baseline to week 12 (part I), treatment with specially formulated SDD capsules (20 mg) 2x daily (1 x every 12 h) for up to 12 weeks was shown to significantly reduce GCF collagenase activity and to improve ALv, effects not seen in patients treated with placebo. Continuous drug therapy over the 12-week treatment period was needed to maintain and maximize the reduction in GCF collagenase and the improvement in ALv. Improvements in periodontal disease parameters occurred without the emergence of doxycycline-resistant micro-organisms. In patients administered an "on-off-on" regimen of SDD over 36 weeks (parts I-III), essentially no attachment loss occurred in patients receiving the highest of these SDD regimens (20 mg 2x daily during part I and 20 mg 1 x daily in part III), whereas patients administered placebo capsules experienced a mean attachment loss of approximately 0.8 mm at the 24- and 36-week time periods. CONCLUSIONS: Doxycycline administered at subantimicrobial doses led to improvements in disease parameters, with no apparent side effects, and appears to have significant potential as an oral adjunctive therapy in the long-term management of adult periodontitis.

A comparative evaluation of tretinoin gel microsphere, 0.1%, versus tretinoin cream, 0.025%, in reducing facial shine.

Tretinoin gel microsphere, 0.1%, is a highly effective anti-acne medication formulated with sponge-like microspheres encapsulating the active ingredient, tretinoin. In addition to minimizing cutaneous irritation, this system may also reduce facial shine. This single-center, double-blind, half-face study evaluated the potential of tretinoin gel microsphere, 0.1%, to reduce the appearance of facial shine compared to tretinoin cream, 0.025%. Thirty-five subjects (ages 12 to 24 years) with moderate acne vulgaris and moderate facial oiliness, were evaluated after 4 consecutive days of product use. On sides treated with tretinoin gel microsphere, 0.1%, investigators found significantly reduced facial shine at 3 and 6 hours posttreatment. Subjects' self-evaluations revealed a significant reduction in facial shine at 3 hours posttreatment. Photographic analyses showed reductions in facial shine for both treatments, but decreases were greater on tretinoin gel microsphere, 0.1%-treated sides. Both therapies were well tolerated, and no adverse events occurred. Tretinoin gel microsphere, 0.1%, has the added benefit of reducing the appearance of facial shine, which is a frequent concern in acne patients.

Treating periodontal diseases by blocking tissue-destructive enzymes.

A new therapeutic approach involves the discovery by the "Stony Brook group," that tetracyclines, but not other antibiotics, can inhibit host-derived collagen-destructive enzymes. This newly discovered property of tetracyclines is unrelated to the antimicrobial activity of these drugs. Examples support the hypothesis that this unexpected property of tetracyclines provides a new approach to treating periodontal diseases as well as a variety of medical disorders.

An evaluation of 6 dentifrice formulations for supragingival anticalculus and antiplaque activity.

A 4 week, double blind clinical trial was conducted to assess the antiplaque/anticalculus activity of test dentifrices containing varying levels of zinc citrate. Subjects were divided into 6 groups, 4 experimental, 1 positive control and a placebo group. All subjects only brushed at home using the placebo control during study weeks 1 and 3. Plaque and calculus were collected at the end of study weeks 2 and 4 on mylar strips worn on lower incisor teeth. Dentifrice efficacy was assessed by comparing group dry and ash weight decrements. While there were no significant differences between the test and control groups, there was a demonstrable trend toward greater inhibition with higher zinc citrate levels, especially among subjects with high levels of plaque and calculus at baseline.