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Effects of H2O2 on bone were evaluated in an organ culture system. Tibiae from chick embryos were incubated for up to 3 days in culture medium containing 0.07 to 20 mM H2O2. Glucose metabolism was monitored by measuring lactate production and oxygen consumption, and collagen synthesis was determined by hydroxylation of proline. In addition to markedly inhibiting these parameters, H2O2 also decreased bone weight and alkaline phosphatase activity. Multiple exposures to H2O2 were somewhat more effective than a single exposure. Since H2O2 inhibits bone at low concentrations in vitro, the results suggest that the potential for harmful effects of H2O2 in the oral cavity should be investigated.

This was a double-blind, radomized, crossover study of adult subjects to evaluate the effect of a test mouthrinse (Cepacol) on plaque accumulation. The study was divided into two parts, four weeks each, one in which only a mouthwash was used (part I) and the other in which a mouthwash and toothbrushing were used (part II). 1. The test mouthrinse produced a satistically significant reduction in dental plaque when compared to a placebo rinse. 2. The GI averaged approximately 1.0 throughout the study regardless of which mouthrinse was used. 3. A possible carryover effect of the test mouthrinse was noted. 4. A lower plaque score was seen in 67 to 75% of all patients during the period in which the test mouthrinse was used as compared to the placebo. 5. Ten subjects reported a burning sensation of the tongue with the test mouthrinse. No objective adverse effects were seen.

Bacteremia that occurs after dental extraction is common. This study assessed the effect of topical antisepsis on the incidence and magnitude of post-extraction bacteremia. On hundred patients scheduled for elective tooth extraction were randomized among four groups: contr-l, mouthrinsing with sodium-p-toluene sulfonchloramide (chloramine-T), toothbrushing with chloramine-T, and irrigation with Lugol's solution. The results showed that 84% of the control group and 59% of the treatment groups had positive blood cultures (290 organisms isolated) after dental extraction. The duration and magnitude of these bacteremias were diminutive as documented by the six serial blood cultures taken for each patient, colony counts per milliliter of blood, and nitroblue tetrazolium and Limulus assays. Brushing the teeth or rinsing the mouth with chloramine-T before dental extraction significantly reduced the incidence of bacteremia (P less than .025) and the number of different organisms recovered from each patient (P less than .05). Thus, topical treatment with chloramine-T is a simple and effective means of reducing the incidence of postextraction bacteremia.

This study was undertaken to determine whether long-term use (6-months) of an antiseptic mouthrinse (Listerine Antiseptic, Warner Lambert Co., Morris Plains, NJ, USA) led to an undesirable succession of oral pathogens or the emergence of resistant microbial forms. Supragingival plaque was collected from 83 subjects before treatment and after either 3 or 6 months use of either the active antiseptic or a 5% hydroalcohol control. Subjects rinsed with their assigned mouthrinse twice daily under supervision. The plaque samples were analyzed for microbial content by darkfield microscopy, culture on a series of nonselective and selective bacterial media, and by recognition of microbial forms by recognition of distinct colony on a nonselective medium. Statistical analysis of the results revealed no significant microbial shifts including no significant increases in presumptive oral pathogens, spirochetes, black-pigmented Bacteroides, Streptococcus mutans, or Candida albicans. Additionally, no detectable rise in either staphylococci or enteric bacteria, potential opportunistic pathogens, was observed.

A new electric pulp-testing system, the Testark, was developed in order to assess the potential of a different way of testing pulp sensitivity, thus making this electric pulp test more dependable than the conventional electric pulp-testing method. A study was conducted to evaluate the potential of the Testark system in comparison with a commercially available pulp tester. This pilot study consisted of application of three different desensitizing agents (sodium fluoride, test product. 'A', and test product 'B') to the cervical areas of hypersensitive teeth. The results were recorded with both the Testark and the conventional pulp tester simultaneously, and the sodium fluoride and test product 'B' proved to yield a beneficial effect by desensitizing the teeth after a single application. The level of desensitization with these agents was higher than the level obtained with the test product 'A' paste, which was utilized daily for 14 days. The results obtained with the conventional pulp tester differed by way of interpretation from those obtained with the Testark system. The Testark system proved to be easy to use and highly accurate in the data readings because of its high resolution. The Testark systemwas found to be more dependable than the commerical pulp tester, since it reduced the subjective errors which are inevitable when a commerical pulp tester is used. The Testark system is being developed further, and more studies are being conducted at the present time, in order to assess the full potential of the instrument.

A blind crossover trial was carried out to compare the effects of a 0.2% chlorhexidine gluconate mouthrinse and a 0.035% alexidine mouthrinse on plaque accumulation and salivary bacteria in a group of volunteers. The subjects refrained from all forms of oral hygiene during two 10-day periods and rinsed twice a day with the mouthwash randomly allocated to the respective period. Prerinse, day 4 and day 10 total salivary aerobic and anaerobic bacterial counts were determined during each period. Plaque scores were recorded at the end of each 10-day period. Significantly more plaque accumulated in subjects rinsing with alexidine when compared with chlorhexidine. Significant and comparable reductions in salivary bacterial counts were observed with both chlorhexidine and alexidine on day 4 and day 10 when compared with pre-rinse counts. Although at the concentrations used alexidine was less effective than chlorhexidine, it may be of value as a short-term adjunct to oral hygiene.

Odorigenic gram-negative anaerobes in human gingival crevices were significantly decreased for up to 120 minutes after rinsing with an antiseptic mouthwash. This observation parallels clinical measurements of the antiseptic effect on oral malodor and suggests that its odor-decreasing properties are related to its antimicrobial action in the mouth.

We investigated the possible contribution made by oropharyngeal microfloral fermentation of ingested carbohydrate to the generation of the early, transient exhaled breath hydrogen rise seen after carbohydrate ingestion. Ten subjects ate or were sham fed carbohydrate-containing meals with and without prior chlorhexidine mouthwash during serial collection of exhaled breath and mouth hydrogen samples. Meal ingestion and sham feeding both induced significant (p less than 0.01) elevations of breath and mouth hydrogen that were virtually abolished by prior chlorhexidine mouthwash. In 7 subjects, delivery of the meal directly into the stomach via an orogastric tube did not cause a breath or mouth hydrogen rise. Oral contents incubated anaerobically in vitro with carbohydrate generated hydrogen that was again inhibited by chlorhexidine. These studies indicate that fermentation of ingested carbohydrate by oropharyngeal bacteria can contribute significantly to measured breath hydrogen values soon after meal ingestion, and may introduce avoidable error into the interpretation of serial breath hydrogen data.

Two groups of probands have been studied: experimental and control. After the clinically performed oral hygiene all probands stopped the brushing of the teeth for a 7-day period. The oral cavity was twice daily rinsed with 10 ml solution for 30 s--with "Antiplaque C" for the experimental and with placebo--for the control. All probands were taken bilateral probe-impressions according to Dzemileva, Stojanova and Popov in the area of 31 tooth, stained by crystal-violet and observed under light microscope and immersion. The cytological finding in the experimental group did not reveal an inflammatory process in the gingival sulcus whereas increased gingival exudate was established in the placebo group as well as intensified leukocyte migration and single erythrocytes (subclinical phase of inflammation). The bacterioscopic finding in the group, systematically used "Antiplaque C", was reduced to poor dental plaque, preserved "fresh" till the end of the 7-day period being predominantly coccoid-rod-like. In the placebo group the dental plaque "ages"--from coccoid-rod-like it turns into mainly fibril with multiple vibrios and spirillae. The cytological and bacterioscopic data objectivize the inhibitory effect of "Antiplaque C".

A cross-sectional study among 46 xerostomic patients was carried out to determine the influence of a mucin-based artificial saliva on the microflora of standardized oral washings. Patient and non-xerostomic control groups were formed according to the use of saliva substitute (ad libitum or from an intraoral reservoir) and dentition (dentate, edentulous, full dentures). Only few differences were observed among the subgroups based on dentition within a specified salivary group. However, the total number of microorganisms and the proportions of veillonellae, actinomycetes, streptococci and S. salivarius were significantly reduced in xerostomic patients not using artificial saliva, whereas lactobacilli, Candida and S. mitior were significantly increased compared to the control groups. Ad libitum use of artificial saliva had little effect, but semi-continuous wetting of the oral cavity through an intra-oral reservoir reversed the xerostomia-induced shifts in the indigenous microflora. However, no significant effect was observed on the proportions of lactobacilli and yeasts, leaving a potentially acidogenic flora.