Ellen Haugen

The Sensitizing Potential of Periodontal Dressings

The sensitizing potential of three periodontal dressing materials was evaluated by the guinea pig maximization test. The results indicated a difference in the sensitization rate of the three materials.

In Vitro Cytotoxicity of Periodontal Dressings

The cytotoxicity of three periodontal dressings was evaluated by two in vitro cell culture techniques. Fresh and stored materials were found to be cytotoxic by both techniques and it appeared that the mechanism of cytotoxicity was different for the three dressing materials tested.

The effect of chlorhexidine supplementation in a periodontal dressing

Most commercial periodontal dressings claiming antibacterial activity lose this activity shortly after application. Chlorhexidine (CH) is an antibacterial agent with long-term activity in the oral cavity owing to its substantiveness and slow-release properties. In a double-blind split-mouth-designed clinical trial the effect of incorporating CH acetate in periodontal dressing was tested on wound healing after gingivectomy. Eleven patients, each needing at least two gingivectomies, constituted the test panel. Wound healing, as assessed by bleeding tendency after removal of dressing 7 days postoperatively was significantly delayed when control dressings were applied as compared with test dressings. Variables with regard to patient comfort also yielded results in favor of the test pack. Incorporation of antibacterial agents with high retention and slow release properties in the mouth in surgical dressings seems advantageous.

Dimensional Changes of Periodontal Dressings

The linear dimensional changes of three commercial periodontal dressings were measured during 24 hours. The dressings revealed different degrees of dimensional changes, which may indicate that they exhibit variations in adaptation to wound surfaces.

The effect of periodontal dressings on intact mucous membrane and on wound healing. A methodological study.

Biological screening of dental materials which are intended for use in contact with the oral mucosa comprises a mucous membrane irritation test. The aim of the present investigation was to study the effect of 3 periodontal dressings on intact oral mucosa and to assess their effect on the epithelial proliferation during wound healing. A total of 87 rats were used, 24 for studying reactions in intact mucosa and 63 for a wound healing study. A wound was inflicted on each animal in the palate behind the incisors. The dressing covered the wound area and the surrounding mucosa and was secured by an appliance fixed to the maxillary incisors. 3H-labelled thymidine was injected prior to sacrifice after observation periods of 1, 3 and 5 days. Histological assessment and autoradiographic evaluation of mitotic activity were performed. The dressings caused no reaction in the intact mucosa. In the wound healing study the mitotic activity at day 1 was lower in test than in control animals indicating a toxic effect of all materials. No differences between the 3 dressings were found. After 5 days, all wounds were covered by epithelium. Neither at 3 nor at 5 days were any differences between test and control animals seen.

Sensitization of guinea pigs with chlorhexidine.

Guinea pigs were immunized with autologous serum exposed to chlorhexidine gluconate. Injections were given every second day for one week. After four weeks the animals were given a booster-dose and were tested for antibodies using the cutaneous anaphylaxis test. The titre of chlorhexidine-treated serum showing a positive reaction was 1: 1000 in immunized animals. Control animals showed positive reaction in a dilution of 1: 10 but negative in 1: 100.

Methods for evaluation of working and setting times of periodontal dressings.

Three different methods were used to determine working and setting times of periodontal dressings. The Gillmore needle and the rheometer employed were not suitable for recording setting reactions. A penetration test was found applicable for determination of working and setting times for all three dressings although they exhibited different setting characteristics.