The effect of mouthrinses and topical application of chlorhexidine on the development of dental plaque and gingivitis in man

Twenty-four male dental students with healthy gingivae and clean teeth ceased all oral hygiene procedures. (A) Four subjects rinsed, twice daily, with a 0.2 per cent solution of chlorhexidine gluconate; (B) eight students rinsed, once daily, with the same solution; (C) six students did not rinse and formed the control group and (D) six students received one daily application of a 2 per cent solution of chlorhexidine gluconate. The study confirmed previous observations (Löe and Rindom Schiött 1969, 1970) that two daily mouth rinses with a 0.2 per cent solution of chlorhexidine effectively prevent plaque formation. One daily rinse did not inhibit plaque formation in all areas of the dentition. One daily topical application of a 2 per cent solution of chlorhexidine gluconate prevented plaque formation completely. Upon discontinuation of the chlorhexidine treatment plaque formed at normal rates, suggesting that there is no appreciable effect beyond a 24 hour period. It is concluded that complete inhibition of plaque and prevention of gingivitis may be achieved by daily application of chlorhexidine, provided the agent is administered in such a way that it reaches all tooth surfaces.     

Rinsing with delmopinol 0.2% and chlorhexidine 0.2%: short-term effect on salivary microbiology, plaque, and gingivitis.

The aim of this short-term study was to compare the effect of delmopinol HCl 0.2% and chlorhexidine digluconate 0.2% rinses on the development of dental plaque, the healing of experimental gingivitis, and the salivary microbiology. As part of a larger study protocol, 45 healthy males enrolled in an oral hygiene program to upgrade their oral health. For this portion of the study, participants had their teeth professionally cleaned on day 0. The participants then abstained from standard mechanical oral hygiene procedures, but applied a placebo solution twice daily for 2 weeks. At the end of this period the subjects received a second professional cleaning and were then assigned to 2 treatment groups: Group 1 rinsed with 10 ml of delmopinol HCl 0.2% and Group 2 rinsed with 10 ml of chlorhexidine digluconate 0.2% for 1 minute twice daily for the next 2 weeks and continued to refrain from mechanical oral hygiene procedures. At the end of the placebo and active treatment periods 1) saliva samples were taken and cultivated on a series of media; 2) the degree of gingivitis was assessed with gingival crevicular fluid (GCF) and gingivitis index (GI); and 3) the plaque index was assessed and the stainable buccal plaque extension was analyzed planimetrically. No changes in the salivary microbiological counts were detected for the subjects rinsing with delmopinol. Subjects rinsing with chlorhexidine showed significant reductions of anaerobes, aerobes, and S. mutans in saliva. The amounts of GCF and GI were reduced largely to the same extent in both treatment groups. Mean plaque extension was reduced by 52% after delmopinol and 88% after chlorhexidine rinsing.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of the bisbiguanide antiseptics alexidine and chlorhexidine. I. Effect on plaque accumulation and salivary bacteria

Abstract 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.     

The effects of a 0.2% chlorhexidine gluconate mouthrinse on plaque, toothstaining and candida in aphthous ulcer patients

Despite the known effectiveness of 0.2% chlorhexidine gluconate mouthwash in preventing plaque formation, relatively few studies have assessed adjunctive benefit to normal unsupervised oral hygiene measures. Furthermore, there have been few accurate measurements of toothstaining in the presence of normal oral hygiene and little data of effects on oral candidal carriage. This study was a double-blind placebo-controlled cross-over study of a 0.2% chlorhexidine gluconate mouthwash used 3 times daily on plaque, staining and candidal carriage in a group of recurrent aphthous ulcer suffers who maintained normal oral hygiene measures. At the end of 2 6-week treatment periods, baseline plaque scores were reduced by active and placebo mouthwashes. Chlorhexidine significantly reduced plaque compared to the placebo. Staining has markedly and significantly increased during chlorhexidine rinsing. Candidal carriage was present in 22.2% of this group and there was no significant effect of chlorhexidine on the mean number of candidal colonies. The distribution of plaque and staining by tooth was plotted and observationally studied. Baseline and placebo treatment plaque distributions indicated the considerable relevance of toothbrushing behaviour for plaque distribution. The effects of toothbrushing on plaque distribution were minimised during the use of chlorhexidine. Staining associated with chlorhexidine showed a distribution again suggesting the influence of toothbrushing. In conclusion, chlorhexidine has significant adjunctive effects on plaque inhibition in the presence of normal unsupervised oral hygiene, but toothbrushing did not prevent toothstaining.     

The effect of delmopinol rinsing on dental plaque formation and gingivitis healing

The aim of this study was to investigate a possible dose-response effect of delmopinol hydrochloride, on the development of plaque and on the healing of gingivitis. 64 healthy male volunteers, aged 18-40 years with healthy gingivae and clean teeth, participated. During a 2-week period, the participants refrained from all oral hygiene and rinsed 2x daily with a placebo solution. On day 14 of the study, they received professional toothcleaning, and were randomly assigned to 4 groups. For the following 2 weeks, they rinsed 2x daily for 1 min with 10 ml of 0.05% (15 subjects), 0.1% (17) or 0.2% (16) delmopinol, respectively. 16 subjects rinsed with 0.2% chlorhexidine. No oral hygiene procedures were performed during the test period. On days 0, 14 and 28, gingival bleeding index and the presence of stainable plaque were determined. Periodic identical photographs were used for planimetric determination of buccal plaque extension. No significant difference for the reduction in gingival bleeding index was found between 0.2% delmopinol and chlorhexidine rinsing. The mean plaque index showed its most significant reduction on lingual surfaces of both upper and lower jaws when rinsing with 0.2% delmopinol. Mean plaque extension was reduced by 23% for 0.05%, 39% for 0.1% and 55% for 0.2% delmopinol. A significant dose-response effect for 0.05%, 0.1% and 0.2% delmopinol was found for gingival bleeding index, plaque index and plaque extension. The results show that delmopinol favors the healing of gingivitis and reduces plaque formation.     

Effect of chlorhexidine gluconate mouthrinse on plaque bacteria

The antimicrobial effect of a 0.12% chlorhexidine gluconate mouthrinse on plaque bacteria was compared to that of a placebo mouthrinse without chlorhexidine gluconate. Forty subjects in each treatment group rinsed twice daily with 15 ml mouthwash for six months. They were instructed to continue their usual oral hygiene practices. After six months, the subjects stopped using the mouthrinse. Supragingival plaque was collected from each subject and assayed for eight representative microbial populations at baseline, after three and six months of treatment, and after a three-month post-treatment period.
During the six months of mouthrinse use, significant reductions in the numbers of total aerobes. total anaerobes, streptococci, and actinomyces were observed in plaque samples taken from subjects using the chlorhexidine mouthrinse. The effect of chlorhexidine on actinomyces accumulation was especially pronounced with reductions ranging from 85–97%. This was considered to be particularly significant since actinomyces is one of the bacteria known to be periodontopathic in both experimental animals and in humans. Although chlorhexidine treatment reduced the number of microbes on teeth, it did not produce a detectable shift in microbial populations.
At the end of the three-month post-treatment period, the microbial profile was similar to the pre-treatment profile for both groups. Therefore, no residual effects of chlorhexidine on plaque bacteria were observed after cessation of rinsing.     

Efficacy of Listerine®, Meridol® and chlorhexidine mouthrinses on plaque, gingivitis and plaque bacteria vitality

The experimental gingivitis model was used to compare the anti-plaque, anti-gingivitis and anti-microbial efficacies of a phenolic compound (Listerine) and an amine/stannous fluoride mouthwash (Meridol), using a placebo preparation as negative control and a chlorhexidine solution as positive control in a double-blind study. After professional toothcleaning, 36 volunteers performed optimal oral hygiene for a period of 2 weeks. They then ceased all oral hygiene procedures for 21 days during which they rinsed twice daily with 1 of the 4 mouthrinses. After 3 weeks of rinsing, plaque indices remained the lowest in the chlorhexidine group, while subjects using Listerine or Meridol harbored similar indices significantly lower than that of individuals rinsing with the placebo solution. Up to that time, the gingival index scores were equal in all groups except for the chlorhexidine group in which the values only amounted to half of these encountered in the other groups. The plaque vitality scores showed a bactericidal effect in vivo of chlorhexidine during the entire time of experimental gingivitis. In contrast, the data gave no evidence of an antibacterial effect in vivo of Listerine. The efficacy of Meridol to kill micro-organisms was similar to chlorhexidine during the early stages of plaque accumulation and, with time, became insignificant. This study has demonstrated that chlorhexidine was superior to Listerine and Meridol in its ability to maintain low plaque scores and gingival health during this 3-week period of no mechanical oral hygiene. Moreover, it was also shown that Meridol was as effective as Listerine in reducing plaque accumulation and, in contrast to Listerine, possessed a remarkable but transient antibacterial effect in vivo.     

Optimal dosage of chlorhexidine digluconate in chemical plaque control when applied by the oral irrigator

Abstract Chlorhexidine digluconate for chemical plaque control was tested in different concentrations using a fractionated jet oral irrigator. The inhibition of plaque formation and the prevention of gingival inflammation were evaluated in a double-blind study. During a 10-day period of abstinence from any mechanical oral hygiene procedures, the pattern of plaque formation and gingivitis development under the influence of chemical plaque control was analyzed. As a positive control, one group rinsed twice daily with 30 ml of a 0.2% chlorhexidine solution while a group applying 600 ml of a placebo solution served as a negative control. Forty dental students and assistants with plaque-free dentitions and healthy gingival tissues were divided into four groups. After a 10-day period of no oral hygiene, a recovery period of 11 days with perfect oral hygiene was again instituted. This experiment was repealed three times so that a total of 10 concentrations in the irrigator, the control rinsing and the placebo control could be evaluated. Daily application of 600 ml of a 0.001%(6 mg), 0.0033% (20 mg), 0.005% (30mg), 0.01% (60 mg), 0.02% (120 mg), 0.05% (300 mg) and 0.1% (600 mg) and 400 ml of a 0.015 % (60 mg), twice 400 ml of a 0.015% (120 mg) and 400 ml of a 0.02% (SO mg) solution of chlorhexidine was tested. At the start of each experimental period (day 0), after 3, 7 and 10 days and 11 days following reassuming oral hygiene procedures, the plaque accumulations were determined using the Plaque Index System (Silness & Löe 1964) and the development of gingivitis was evaluated according to the criteria of the Gingival Index System (Löe & Silness 1963). The results suggested that one daily irrigator application of 400 ml of a 0.02 % chlorhexidine solution was the optimal and lowest concentration and dose to be used for complete inhibition of dental plaque.     

The effect of chlorhexidine mouthrinses on the human oral flora

The purpose of the present study was to examine the effect of chlorhexidine mouthrinses on the oral flora. Four students rinsed, twice daily, with 10 ml of a 0.2 per cent solution of chlorhexidine gluconate, and four students served as controls on a no oral hygiene programme. The number of bacteria in saliva was estimated by a cultural technique and impression preparations were used for the study of the bacteria on the gingiva and tooth surface. The controls showed a 300 per cent increase in bacterial counts during the experiment. In the chlorhexidine group the number of bacteria per ml saliva was reduced by 85 per cent, after 24 hours, reaching a 95 per cent reduction on day 5. An 85–90 per cent reduction was maintained throughout the experimental period. Impression preparations of the gingival area in the controls showed a heavier accummulation of bacteria than in the chlorhexidine group. In addition an increasing bacterial colonization of the tooth surfaces occurred in the controls throughout the experiment, but was never observed in the chlorhexidine group. Although the number of bacteria in saliva was markedly reduced, large numbers still persisted. It, therefore, appears unlikely that the inhibition of plaque formation is primarily the result of a reduction of the salivary flora.     

Use of oral irrigators as vehicle for the application of antimicrobial agents in chemical plaque control

Abstract The purpose of the present investigation was to study the topographical distribution of plaque formation using chlorhexidine digluconate (CH) as a mouthrinse and in oral irrigators during experimental gingivitis. Forty dental students (aged 22–26) with clean teeth and healthy gingivae abolished oral hygiene oral period of 3 weeks (Löe et al. 1965). During this period the participants were randomly assigned to one of five groups, Group A rinsed daily with 30 ml of a placebo and Group B with 30 ml 0.1% chlorhexidine digluconate. In Groups C and E a fractionated jet irrigator was used for the daily application of 600 ml placebo (C) or O.05% CH (E); 600 ml of 0.05% CH was also used in a monojet irrigator (Group D). At the start, after 1, 2 and 3 weeks of no oral hygiene and 1 week following reinstituted oral hygiene, plaque was assessed using the Plaque Index (Silness &. Löe 1964) and gingival health was scored according to the criteria of the Gingival Index (Löe & Silness 1963). The discoloration of the teeth was determined using a set of color photos. During the experiment all groups reached plaque levels that were significantly different from each other. The highest PII were seen in the placebo rinsing group (A) followed by placebo irrigation (C). Plaque was significantly reduced in the CH groups. However, rinsing (B) formed significantly more plaque than using the oral irrigator (D, E). Group E showed the least amount of plaque. In addition, the interproximal PII were equally low as the buccal and lingual. With CH (B, D, E), gingivitis did not develop except for some interproximals in Group B. A fractionated jet irrigator was more effective for the application of CH than rinsing.     

Efficacy of supervised rinsing with chlorhexidine digluconate in comparison to phenolic and plant alkaloid compounds

The experimental gingivitis model was used to compare the antigingivitis, antiplaque, and antimicrobial efficacies of two commercially available (a phenolic and a plant alkaloid) compounds used as mouthrinses with those of a mouthrinse containing chlorhexidine digluconate. Thirty-one male and female volunteers with healthy gingivae and clean teeth ceased all oral hygiene procedures for 21 days during which they rinsed twice daily with: a) a phenolic compound (Listerine^®), b) sanguinarine (Viadent^®), c) 0.12% chlorhexidine digluconate, or d) a placebo mouthrinse. After 21 days of rinsing, virtually no signs of clinical gingivitis were observed in the chlorhexidine group. Subjects rinsing with Listerine, Viadent, or placebo developed clinical signs of gingivitis as measured by gingivitis occurrence, severity, and the proportion of gingival bleeding sites. At the same time, plaque accumulation was only slightly higher than at baseline in the chlorhexidine group, while the Listerine, Viadent, and placebo groups had significantly greater plaque accumulations, particularly during the initial period of treatment between day 0 and day 7. Microbiological enumeration of supragingival plaque collected at the end of the treatment period showed that chlorhexidine digluconate reduced plaque bacteria by 62–62% compared to the placebo group. No significant reductions in plaque bacteria were found among subjects using Listerine or Viadent.
This study demonstrated that 0.12% chlorhexidine digluconate was superior to Listerine and Viadent in its ability to maintain optimal gingival health during the entire three weeks of mouthrinse use. It was of particular interest to note these effects during the final 14 to 21-day period of extreme challenge in this experimental model when gingivitis severity and bleeding site occurrence are most pronounced in the placebo group.     

Plaque formation and gingivitis after supervised mouthrinsing with 0.2% delmopinol hydrochloride, 0.2% chlorhexidine digluconate and placebo for 6 months

OBJECTIVES AND METHODS: A double-blind, randomized, 6-month clinical trial with parallel group design in 162 patients with gingivitis divided into three rinsing groups was conducted in order to study the efficacy and safety of a flavoured solution of delmopinol hydrochloride 2 mg ml“‘ (0.2% w/v, Decapinol Mouthwash”^®) used for supervised mouthrinsing in one rinsing group, in comparison with chlorhexidine digluconate 2 mg ml^-1 (0.2% w/v, Hibitane Dental’^{a, b}) in a second rinsing group, and placebo in the third group. The criteria of the Plaque Index (PI) were used to assess plaque formation. Bleeding on probing (BOP) to the bottom of the pocket with a standard pressure was used as the primary gingivitis assessment. The occurrence of supragingival dental calculus and extrinsic tooth staining were also assessed. In addition, patients were asked to report adverse events at each visit. RESULTS: Delmopinol and chlorhexidine exhibited lower scores of the mean PI and the BOP percentage than placebo, both at the 3-month and 6-month examinations. Furthermore, both active solutions showed a higher extent of staining of the teeth than placebo during these two observation periods. Rinsing with chlorhexidine resulted in more dental calculus than placebo after 6 months. Chlorhexidine showed lower scores for plaque formation and gingivitis development but higher scores of supragingival dental calculus (after 6 months) and tooth staining than did delmopinol. Both active solutions were reported by the patients–approximately to the same extent but more frequently than placebo–to induce taste alterations and a transient anaesthetic sensation of the oral mucosa. However, subjective staining of the teeth and tongue was reported by 16% of the delmopinol patients, but by 86% of the patients rinsing with chlorhexidine for 6 months. Furthermore, 24% of the patients in the chlorhexidine group, 9% in the delmopinol group and 4% in the placebo group wished to withdraw from treatment. CONCLUSIONS: The results from this clinical trial indicate that supervised rinsing with 0.2% delmopinol hydrochloride or with 0.2% chlorhexidine digluconate twice daily for 60 s as a supplement to normal mechanical oral hygiene procedures resulted in less plaque formation and gingivitis than rinsing with placebo. Although chlorhexidine was more effective than delmopinol regarding plaque formation and gingivitis, it was considered by the patients as less tolerable.     

Comparison of plaque accumulation after topical application and mouth rinsing with chlorhexidine gluconate

This study measured plaque accumulation on anterior teeth after topical or mouth rinse application of 0.2% chlorhexidine gluconate. Compared with water plaque scores were highly significantly reduced. There was no significant difference in plaque scores between topical application or mouth rinsing. The importance of locally adsorbed chlorhexidine is emphasised and the relevance of an oral reservoir effect questioned.     

The mechanism of action of chlorhexidine

Controversy exists concerning the mode of action of chlorhexidine in plaque inhibition. This study attempted to determine whether an oral reservoir of chlorhexidine was necessary for plaque inhibition. Plaque growth on enamel under the influence of topically applied or rinsed chlorhexidine was closely monitored by clinical scoring, bacterial culturing and scanning electron microscopy. Thus, 3 subjects wore removable acrylic appliances containing enamel inserts. In the first regimen, inserts on one side of the appliances were exposed to 0.2% chlorhexidine and on the other, water for 1 min twice a day for 14 days. In the second regimen, subjects rinsed with 0.2% chlorhexidine for 1 min twice a day for 14 days with the appliances in situ. Results demonstrated that plaque growth assessed by the 3 study methods was very small on chlorhexidine-treated inserts by comparison with water-treated specimens. Importantly, inserts treated with chlorhexidine topically or by rinsing could not be distinguished by any method of evaluation. It is concluded that chlorhexidine achieves plaque inhibition as a result of an immediate bactericidal action during the time of application and a prolonged bacteriostatic action as a result of adsorption to the pellicle coated enamel surface. Consistent with other clinical studies, it is apparent that a progressively desorbing oral reservoir of antiseptic is not the mechanism by which chlorhexidine achieves plaque inhibition on teeth.     

Three different rinsing times and inhibition of plaque accumulation with chlorhexidine

AIM: This study assessed the plaque inhibiting effect of a 0.2% chlorhexidine (CHX) solution (Corsodyl) with three different rinsing times following a 72 h non-brushing period. MATERIAL AND METHODS: The clinical investigation was a single-blind, randomised study involving 90 volunteer students (40 male and 50 female, mean age 23.2 years). Subjects were randomly allocated to one of three groups for which the protocol only differed with respect to the duration of rinsing. At the start of the trial, all participants received a dental prophylaxis to remove all plaque deposits. Subjects refrained from all mechanical oral hygiene procedures, but rinsed two times per day for the allocated duration with CHX mouth rinse over a period of 72 h. The chlorhexidine preparation was of 0.2% concentration used at a dose of 10 ml for either 15, 30 or 60 s. After 72 h, the Quigley & Hein plaque index (PI) from all volunteers was recorded at six sites per tooth. All participants received a questionnaire to evaluate their perception of rinsing duration. RESULTS: After 72 h, the mean whole-mouth PI was 1.33, 1.18 and 1.24, respectively, for the 15, 30 and 60 s rinsing group. The difference in plaque scores between the three groups was not statistically significant. Results from the questionnaire showed a significant difference between the groups for their perception of rinsing duration. CONCLUSIONS: No significant difference was observed in the level of plaque after 72 h of non-brushing whether the subjects rinsed for 15, 30 or 60 s with 0.2% chlorhexidine.     

Effects of chlorhexidine mouthrinse on oral health in patients with acute leukemia

The effects of chlorhexidine mouthrinses, used as a supplement to mechanical oral hygiene measures, were studied in patients receiving treatment for acute leukemia. Twenty-eight patients were randomly divided into two groups. During two periods, when the patients were taking medication for the leukemia, one group rinsed with a 0.2% chlorhexidine solution twice daily and the other group did not. Chlorhexidine had no effects of any clinical significance on parameters such as number of days with fever, number of oral lesions, plaque score, gingival bleeding score, or occurrence of candidiasis. There was, however, an increased number of patients who had a burning sensation in the mouth, and a tendency toward increased numbers of salivary enterococci, enterobacteria, and/or Pseudomonas in patients who rinsed with chlorhexidine. The results of the present study do not support the use of chlorhexidine mouthrinses in patients who are able to maintain good oral hygiene by mechanical means during their illness.     

Efficacy of antiplaque mouthwashes: a five-day clinical trial

The aim of this study was to evaluate and compare the efficacy of antiplaque mouthwashes. Plaque levels were determined by applying a plaque-disclosing solution using the Turesky et al modification of the Quigley Hein plaque index. The control group (n = 6) brushed twice per day with fluoride toothpaste for one minute and rinsed with water, while the study groups (n = 6) brushed once per day with fluoride toothpaste for one minute, followed by rinsing with 5.0 mL of mouthwash diluted with 10.0 mL of water for 30 seconds. The control group brushed and rinsed with water twice per day. The results indicated that cetylpyridinium chloride in combination with sodium fluoride offered maximum plaque inhibition, followed by chlorhexidine gluconate and sodium monofluorophosphate, while plaque levels increased in the control group and with the combination of chlorhexidine gluconate and sodium fluoride. The only antiplaque agents to demonstrate a statistically significant difference from the control were cetylpyridinium chloride in combination with sodium fluoride, and chlorhexidine gluconate. Increasing the fluoride concentration had no impact on antiplaque activity.     

Plaque control with chlorhexidine and D-301, a quaternary ammonium compound

Eighteen female dental hygiene students took part in a double-blind, crossover clinical trial of equimolar (2.2 mmol) rinsing solutions of D-301, a quaternary ammonium compound and chlorhexidine digluconate, Rinsings were partly supervised, test periods were 7 days (5 days without oral hygiene) with a 1-week interval. Plaque formation was significantly reduced by both test solutions versus the control; on not precleaned tooth surfaces plaque formation was equally inhibited by the chlorhexidine and D-301 mouthrinses. On precleaned surfaces D-301 significantly inhibited plaque formation compared with the control rinse, but was less effective than chlorhexidine. There was no significant change in the PBI, a measure of gingival inflammation, during any of the test period. Staining of teeth and tongue was judged as equal after chlorhexidine and D-301 use. Reports of taste and gastric disturbances were minimal but more frequent during the D-301 test period.     

Quality-specific taste impairment following the application of chlorhexidine digluconate mouthrinses

Although chlorhexidine has been widely used in the prevention and treatment of gingivitis, its effects on taste sensation have not been well studied. The purpose of the present study was to evaluate taste alterations following regular applications of 0.2% chlorhexidine mouthrinses. 24 healthy and non-smoking clinical instructors, dental assistants and dental students were divided into 3 groups after having reached a status of clinical gingival health by 4 weeks of supervised oral hygiene procedures. Following this, they were asked to abolish all mechanical oral hygiene for a period of 14 days, during which time they rinsed twice daily with different mouthrinses. Group A rinsed with a 0.2% chlorhexidine solution, group B served as control and utilized a 0.001 molar solution of quinine hydrochloride as a placebo rinse. A second control group (C) rinsed with distilled water. At days -3 and -2, as well as at days 1, 2, 13 and 14 of the experimental period, and 1 and 2 days after cessation of the rinsing, taste sensitivity was evaluated by a magnitude estimation, suprathreshold scaling procedure for the 4 taste qualities--sweet, salty, sour and bitter. 6 different concentrations of each of sucrose, sodium chloride, citric acid and quinine hydrochloride were utilized. Magnitude estimations of the perceived intensities of each series of test solutions were calculated. The analysis of co-variance revealed significant differences at the short-term and treatment-related suprathreshold scaling responses between both control groups (B, C) and the test group (A) for the sodium chloride magnitude estimation function. However, no significant inter-group differences in the magnitude estimation function were found for the remaining taste qualities.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of chlorhexidine mouthrinse on healing after gingivectomy

abstract – The purpose of this investigation was to evaluate the effect of 0.2 % chlorhexidine gluconate mouthrinse following gingivectomy on plaque under the dressing and on healing. Twenty-eight patients with indications for gingivectomy were selected. Coe-Pak® was used as surgical dressing. In addition to usual home care, the patients rinsed twice daily with chlorhexidine or placebo for 21 d after surgery. The study followed a cross-over, double-blind design. Gingival exudate was assessed and P1 I and G I were registered at 7, 14, and 21 d postsurgically. The study indicated that chlorhexidine did not influence the amount of plaque under the dressing, and it was uncertain whether chlorhexidine had any effect on the healing process when the surgical area was covered by Coe-Pak. However, (1) after the surgical dressing was removed, the chlorhexidine maintained plaque scores at the same low level as under the dressing, (2) healing was promoted when chlorhexidine was used, and (3) the presence of a dressing in one side of the mouth did not prevent the patient from maintaining good oral hygiene.