Chlorhexidine-induced changes to human gingival fibroblast collagen and non-collagen protein production

BACKGROUND: Chlorhexidine (CHX) has been used extensively as an adjunctive therapy in the treatment of periodontal disease. It is well known that chlorhexidine is toxic to bacteria, but recent evidence has suggested that chlorhexidine may also have deleterious effects on gingival fibroblast proliferation as well as collagen and non-collagen protein production in cell culture. The purpose of this study was to examine the effects of chlorhexidine on gingival fibroblast proliferation as well as collagen and non-collagen protein production in cell culture. METHODS: Human gingival fibroblasts were incubated in MEM containing chlorhexidine concentrations ranging from 1 microM to 1300 microM at 37 degrees C for 1, 5, or 15 minutes. Control cells received an equal volume of MEM without chlorhexidine for similar times at 37 degrees C. Following incubation, the media were removed, cells washed twice with MEM supplemented with 10% FBS, and fibroblasts in treatment and control groups were allowed to recover in the same media for 24 hours. RESULTS: In all strains, cellular proliferation was dependent on the concentration of solubilized chlorhexidine in cell culture but independent of the duration of chlorhexidine exposure. The average inhibitory concentration necessary to reduce cellular proliferation by 50% (ID50) was 222.1 microM. In regard to collagen and non-collagen protein production, fibroblasts exposed to chlorhexidine concentrations (1 microM) well below the ID50 had a 65% reduction in collagen production and a 57% reduction in noncollagen protein production. CONCLUSIONS: These results suggest that chlorhexidine will induce a dose dependent reduction in cellular proliferation and that concentrations of chlorhexidine that have little effect on cellular proliferation can significantly reduce both collagen and noncollagen protein production of human gingival fibroblasts in vitro. Hence, the introduction of commercially available concentrations (0.12%) or diluted commercial concentrations (as low as 0.00009%) of chlorhexidine to surgical sites for short periods of time prior to wound closure can conceivably have serious toxic effects on gingival fibroblasts and may negatively affect wound healing.     

Effects of low dose chlorhexidine mouthrinses on oral bacteria and salivary microflora including those producing hydrogen sulfide

BACKGROUND/AIMS: Clinical studies have demonstrated the considerable effects of chlorhexidine on dental plaque and oral microbiota as well as improvements in indices of oral health. This investigation examined the efficacy of lower concentrations of chlorhexidine. METHODS: Mouthrinses with 0.03%, 0.06%, 0.12% chlorhexidine and a control rinse without chlorhexidine were examined. Alamar blue, an oxidation-reduction dye with fluorescent end-points proportional to bacterial viability, was used to determine bacterial viability. Further clinical studies examined the effects of these rinses on salivary bacteria and on bacteria producing hydrogen sulfide (H(2)S) and implicated in halitosis. RESULTS: In laboratory tests, a significant dose-dependent effect was observed with Actinomyces viscosus as a model system using the Alamar blue procedure (P < 0.05). Clinical studies examined the effects 1.5 h and 3 h post-treatment on salivary bacteria and bacteria producing H(2)S. The first study compared the control rinse with the 0.03% and 0.06% chlorhexidine rinses; a second study compared the effects of the control rinse and the 0.06% and 0.12% chlorhexidine mouthrinses. In both studies, chlorhexidine rinses demonstrated significant dose-dependent effects post-treatment on salivary bacteria vs. the control rinse (P < 0.05). Significant decreases in H(2)S-producing bacteria were noted with these chlorhexidine rinses vs. the control rinse (P < 0.05). CONCLUSION: The results highlight the dose-dependent relationships noted in laboratory and clinical tests which have potential implications for the use of lower doses of chlorhexidine to inhibit oral bacteria, including those implicated in halitosis.     

Effectiveness of a sanguinarine regimen after scaling and root planing

BACKGROUND: A variety of chemical agents have been evaluated relative to their abilities to inhibit dental plaque and to improve gingival health. Chlorhexidine gluconate is the best known and most widely used member of these agents, but its long-term use is compromised by different side effects, especially extrinsic tooth and tongue staining. Another agent, sanguinarine, which is currently used in both a mouthrinse and toothpaste, leads in some cases only to a transient burning sensation and could be used on a long-term basis. The purpose of this 14-week controlled clinical trial was to assess the effectiveness of a toothpaste and oral rinse containing sanguinaria extract after scaling, root planing and a chlorhexidine regimen. METHODS: Sixty patients diagnosed as having adult periodontitis received initial periodontal therapy including scaling and root planing, followed by a 2-week oral care regimen which included rinsing with 0.2% chlorhexidine gluconate oral rinse. Upon completion of this 2-week initial therapy phase, patients were randomly assigned to either sanguinarine toothpaste and oral rinse or to control toothpaste and oral rinse without sanguinarine. Plaque (modified Quigley-Hein index) and gingivitis (gingival index) were measured prior to periodontal therapy, at the end of the chlorhexidine phase (2 weeks), and after 8 and 14 weeks. RESULTS: Sanguinarine-containing toothpaste and oral rinse significantly inhibited the redevelopment of gingivitis through the 12 weeks following the chlorhexidine phase compared to the control toothpaste and rinse. Patients in the test group had 26% fewer bleeding sites at 8 weeks, and 32% fewer at 14 weeks, than the control group. CONCLUSIONS: Our results support the combined use of chlorhexidine mouthrinse for a short term (2 weeks) followed by sanguinaria mouthrinse and toothpaste up to 3 months in order to optimize the effectiveness of chlorhexidine without side effects. Further studies on the long-term effect of this combination should be established.     

Use of Hibitane following periodontal surgery

A number of studies have assessed the effect of chlorhexidine on the postoperative healing of periodontal wounds. Available data suggest that rinsing with a 0.2% chlorhexidine gluconate solution does not influence healing while a conventional dressing is in place, but once this is removed healing is enhanced by either a chlorhexidine rinse or gel. Dressings incorporating chlorhexidine also hasten wound healing. Studies undertaken in dogs clearly demonstrate that the beneficial effect of this agent is due to its ability to remove existing plaque deposits and prevent new plaque formation.     

Regulation of fibroblast-induced collagen gel contraction by interleukin-1β

Fibroblasts incorporated within collagen gels induce a cell-mediated contraction of the gel to form a three-dimensional, tissue-like structure by a mechanism thought to mimic wound contraction in vivo . In this study a gel contraction model was used to investigate the ability of fibroblasts derived from adult gingiva, adult skin and fetal skin to organise a collagen matrix. In addition the effects of interleukin-1β (IL-1β) on the contraction process was also investigated. Over the concentration range 5-50 U/ml, IL-1β induced a statistically significant inhibition of gel contraction in all fibroblast cell types ( P <0.05), although fetal fibroblasts appeared least responsive and gingival fibroblasts most responsive to the inhibitory effects of this cytokine. Comparison of gel contraction by the different fibroblast strains indicated that fetal and gingival fibroblasts shared similar contraction kinetics. For the adult skin fibroblasts, three of five strains studied showed significantly diminished levels of gel contraction compared to fetal and gingival cells. This apparent difference in fibroblast phenotype may, at least in part, explain the fetal-like wound healing pattern seen in the oral mucosa.     

The effect of triclosan, stannous fluoride and chlorhexidine products on: (I) Plaque regrowth over a 4-day period

A number of substances have been incorporated into toothpastes or gels to inhibit plaque regrowth. The aim of this study was to evaluate triclosan and stannous fluoride products for plaque inhibitory properties by comparison with a chlorhexidine or saline rinse and a control product which was a conventional commercially available toothpaste. In a blind 8 cell cross-over study, 15 volunteers rinsed 2 x a day for 4 days with slurries of the products or the saline and chlorhexidine solutions. No other form of oral hygiene was performed and plaque regrowth from a zero baseline was recorded by plaque score and plaque area. Plaque regrowth was significantly less with the chlorhexidine rinse and significantly greater with the saline rinse compared to the toothpaste and gel products. No significant differences were found between the test and control products. The results again demonstrate that commercially available toothpastes have plaque inhibitory effects which so far appear difficult to improve upon by the addition of specific ingredients, in this case stannous fluoride or triclosan. Commercially available products of known activity would appear useful benchmarks for comparison of experimental formulations.     

Comparison of 2 chlorhexidine mouthwashes on plaque regrowth in vivo and dietary staining in vitro

Abstract Until recently, the few available chlorhexidine mouthrinse products have been 0.2% formulations. However, concentrations of 0.12% chlorhexidine appear as effective as 0.2%, if the volume of the rinse is increased to 15 ml. Since the mere incorporation of chlorhexidine in a formulation does not guarentee availability of the antiseptic, it would seem reasonable to evaluate or compare all products. This is particularly the case when other ingredients, such as fluoride are added. The 1st study compared the effect of a 0.12% chlorhexidine rinse with a 0.12% chlorhexidine/0.022% sodium fluoride rinse for effects on plaque re-growth. The study was a 7-day, blind, randomised, 2-cell cross-over design with a baseline control run in period, in which 18 subjects participated. Both chlorhexidine products significantly reduced plaque compared to control but the chlorhexidine fluoride rinse was less effective than the chlorhexidine only rinse. The 2nd study assessed the propensity of the chlorhexidine rinses to induce dietary staining in vitro. For the chlorhexidine fluoride rinse, this was less than the other 0.12% rinse and a commonly used 0.2% product. The data in vivo and in vitro suggest reduced chlorhexidine availability from the chlorhexidine fluoride product which appears to cause some loss of efficacy.     

Studies on the effect of polyvinyl pyrrolidone on the activity of chlorhexidine mouthrinses: plaque and stain

BACKGROUND, AIMS: Polyvinyl pyrrolidone (PVP) was shown in vitro to reduce chlorhexidine induced, dietary staining without affecting the uptake of the antiseptic to the test substrate. The aim of these studies in vivo was to determine whether PVP affected plaque and dietary staining by a low concentration chlorhexidine rinse. METHODS: The plaque and stain studies used a double blind, randomised 6, treatment crossover design involving healthy subjects with a high standard of oral hygiene and gingival health. The rinse formulations under test were: (A) aqueous alcohol (placebo control), (B) 0.03% chlorhexidine, (C) 0.06% chlorhexidine, (D) 0.06% chlorhexidine+1.2% PVP, (E) 0.06% chlorhexidine+5% PVP, (F) 0.06% chlorhexidine+10% PVP. In the plaque study, on day 1 of each period, subjects were rendered plaque free and then rinsed with 15 ml of the test rinse for 60 s. No further tooth cleaning was performed and subjects returned 24 h later for plaque scoring by area. In the stain study, on day 1 of each period, the tongue and teeth of each subject were rendered stain free. Subjects then rinsed under supervision for 60 s with 15 ml of the allocated rinse 8 x a day between 09:00 h and 17:00 h for 3 days. Immediately after each rinse with the test formulation, subjects rinsed for 120 s with 15 ml of warm black tea. Subjects were requested to also drink at least 5 cups of tea or coffee per day. On day 4, stain was scored by area and intensity from designated teeth and dorsum of the tongue. Washout periods were at least 7 days in both studies. RESULTS: Plaque areas were greatest with placebo and least with 0.06% chlorhexidine. Plaque scores increased with increasing concentrations of PVP in the 0.06% chlorhexidine rinse and were significantly higher than 0.06% chlorhexidine without PVP rinse. Tooth stain areas were comparable for placebo, 0.03% and 0.06% chlorhexidine rinses, but significantly reduced with the PVP/chlorhexidine rinses compared to the 0.06% chlorhexidine rinse. Tooth stain intensity was significantly increased with 0.06% chlorhexidine rinses compared to placebo and chlorhexidine/PVP rinses. Tongue stain area and intensity were significantly reduced with 5% and 10% PVP/chlorhexidine rinses compared to 0.06% chlorhexidine rinse. CONCLUSION: PVP, at the concentrations tested, reduced the stain propensity of a 0.06% chlorhexidine rinse but at the expense of some loss of plaque inhibition.     

A comparison of natural product, triclosan and chlorhexidine mouthrinses on 4-day plaque regrowth

There is a continuing search for ingredients to enhance the chemical plaque inhibitory action of oral hygiene products. Sanguinarine, other natural extracts and triclosan have already been used in products. The aim of this study was to evaluate a number of triclosan and natural product rinses for effects on plaque regrowth. In particular, the influence of other rinse components were assessed, notably sodium lauryl sulphate (SLS) and zinc. The study was a randomised, blind, 9-cell cross-over design to measure the effects of each rinse on 4-day plaque regrowth from a zero baseline. 15 volunteers rinsed 2x daily with each product and plaque was recorded by area and score. The 0.2% chlorhexidine rinse (positive control) was significantly more effective, and the saline rinse (negative control) significantly less effective, than other rinses. Sanguinarine alone was little different from saline and the addition of zinc made a modest improvement in activity. The 3 triclosan/SLS rinses were more effective than the sanguinarine rinses but similar to their minus triclosan control rinse. A natural product/SLS experimental rinse was second to chlorhexidine and, in many analyses, significantly better than all other rinses, but caused some oral erosions. The results indicate that the plaque inhibitory properties of basic ingredients such as SLS may be difficult to enhance or surpass. However, the possible range of recipes, particularly using natural ingredients, provides scope for research and development in the field of oral hygiene products.     

Effects of a chlorhexidine gluconate oral rinse on the incidence of alveolar osteitis in mandibular third molar surgery

Alveolar osteitis (dry socket) continues to be a frequent sequela of third molar surgery. Chlorhexidine 0.12% used as an oral rinse has been reported to reduce the incidence of dry socket. This study compares the effectiveness of 0.12% chlorhexidine used as a preoperative rinse and immediate postextraction irrigant with 1) similarly used 0.05% cetylpyridium, preoperative chlorhexidine rinse and postextraction saline irrigation, and 2) only postextraction irrigation with normal saline in the reduction of alveolar osteitis in mandibular third molar extractions. The results indicate that chlorhexidine and cetylpyridium were no more effective in the reduction of alveolar osteitis than postextraction irrigation with normal saline.     

A comparison of delmopinol and chlorhexidine on plaque regrowth over a 4-day period and salivary bacterial counts

Delmopinol has been considered as a potential agent for the chemical control of plaque. The aims of these studies were to measure the effects of a 0.2% delmopinol hydrochloride mouthrinse on (1) plaque reformation and (2) salivary bacterial counts. Comparisons were made with a 0.2% chlorhexidine rinse and a placebo rinse. A group of 12 male volunteers took part in the plaque study which was of a double blind, randomised, 3 cell, cross-over design. From a zero plaque baseline subjects rinsed, 2x a day, under supervision, for 1 min with 10-ml volumes of the allocated rinse. After 4 days, during which no other form of oral hygiene was performed, plaque was scored by area and index. Plaque results were significantly lower with chlorhexidine and delmopinol compared with control, and with chlorhexidine compared to delmopinol. Side-effects with delmopinol were transient tingling and numbness of the tongue in some subjects. A 2nd group of 12 male volunteers received single, 1-min rinses of the 3 formulations. Salivary bacterial counts were determined immediately before and up to 420 min after rinsing. Compared to the control rinse, chlorhexidine significantly reduced bacterial counts of 420 min. Delmopinol produced a small reduction in bacterial counts which was only significantly different from control at one time point. Delmopinol deserves further evaluation as a chemical plaque inhibitor, particularly when used as an adjunct to normal toothcleaning.     

Comparative staining in vitro and plaque inhibitory properties in vivo of 0.12% and 0.2% chlorhexidine mouthrinses

Abstract. The mere incorporation of an active ingredient in an oral hygiene product does not necessarily guarantee efficacy. As new formulations appear, it would seem prudent to at least screen for activity by comparison with an established product. The aim of this study was to compare a new 0.12% chlorhexidine containing rinse with a well researched 0.2% chlorhexidine rinse product. The rinses were firstly compared in vitro for dietary staining effects and in vivo for plaque inhibition. Both formulations in vitro produced progressive staining of acrylic specimens with increasing passages through a standard tea solution. The clinical investigation was a 3-treatment, randomised, double blind, crossover, 4-day plaque regrowth study, balanced for 1st and 2nd order residual effects and involving 24 volunteers. From a zero plaque baseline, volunteers suspended oral hygiene and rinsed 2×per day with the allocated rinse. The chlorhexidine doses were 18 mg and 20 mg per rinse for the 0.12% and 0.2% formulations, respectively. Plaque was scored by area and index on day 5. The results showed that the 2 chlorhexidine rinses were similar in efficacy by comparison with the control rinse. These studies in vitro and in vivo indicate that the chlorhexidine in the new preparation is available and active and the product could find use in those preventive applications suggested for other chlorhexidine formulations.     

Evaluation of a mouthrinse containing chlorhexidine and fluoride as an adjunct to oral hygiene

Abstract Chlorhexidine and fluoride have valuable preventive roles in dental and oral diseases. There is also evidence that in caries prevention, together, they provide additive benefits. However, combined chlorhexidine/fluoride formulations have rarely been evaluated. The aim of this study was to determine whehter a 0.12% chlorhexidine, 100 ppm F- mouthrinse provided adjunctive oral hygiene benefits compared to a minus active control rinse. The study was a randomised double-blind parallel design involving 102 subjects of whom 99 completed the 6 week experimental period. Subjects rinsed 2 × per day for 1 min with 15 ml of the allocated rinse. Normal toothbrushing procedures were maintained throughout the study. At 6 weeks, plaque and gingivitis scores were significantly lower and the incremental reduction significantly larger in the active rinse group. However, as expected, tooths mining was significantly increased with the active rinse. It is apparent that this chlorhexidine/fluoride rinse could be used in those regimens recommended for other chlorhexidine formulations. The value of the formulation in caries prevention would seem worthy of further investigation.     

Comparison of two commercially available mouth rinses on gingival inflammation, pain and acceptability after third molar surgery

A randomized clinical trial was carried out to compare the difference in the effects of using two different mouth rinses on healing after surgical removal of wisdom teeth. One mouth rinse contained chlorhexidine with alcohol whereas the other was chlorhexidine without alcohol. Twenty-one patients without any medical conditions underwent surgical removal of their 3rd molars by the same operator on both the sides. Data were analysed by the non-parametric function test. Significant differences were shown in the pain score and the number of inflammation sites (p > 0.05). There was no significant difference in the acceptability of the two mouth rinses. In this study, nonalcohol chlorhexidine mouth rinse seemed better than an alcohol-containing chlorhexidine mouth rinse in diminishing patients' post-operative pain and wound inflammation. Non-alcohol chlorhexidine mouth rinse had similar properties without the adverse effects of alcohol, such as dryness of the mouth and addiction. Likewise, they were less likely to result in alcohol-induced pain.     

The effect of chlorhexidine mouth rinses on oral Candida in a group of leukemic patients.

Eighteen leukemic patients were examined for the presence of Candida albicans in the oral cavity. Fifteen patients were found to be Candida "carriers." Nine of the patients were put on a chlorhexidine mouth rinse regimen. Although chlorhexidine was clearly fungicidal in vitro, no decrease in Candida titer was obtained with the mouth rinse. The ineffectiveness of the drug in vivo might be due to the specific location of Candida organisms in the oral mucosa.     

The efficacy of an anti-gingivitis chewing gum

Abstract Chlorhexidine is a well-established agent used for the control of supragingival plaque but is not without disadvantages, such as tooth staining, which limits its clinical applications to short-term use. This clinical trial studied the clinical effectiveness and stain-forming potential of chlorhexidine in a chewing gum base. Subjects (151) were screened for baseline plaque and gingival indices before receiving a dental prophylaxis and randomized into 3 treatment groups: group 1 chewed 2 pieces of chlorhexidine diacetate gum for 10 min 2× a day (total daily chlorhexidine=20 mg). group 2 chewed 2 pieces of placebo gum for 10 min 2× a day and group 3 rinsed with 10 ml of 0.2% chlorhexidine gluconate mouthwash for 1 min 2× per day (total daily chlorhexidine=40 mg). Plaque, gingivitis and stain evaluations were made at 4 and 8 weeks. Plaque and bleeding scores were significantly lower at 4 and 8 weeks in the chlorhexidine gum group compared to the placebo gum group and similar at 8 weeks to the rinse group. Stain intensity at week 8 was significantly less for the chlorhexidine gum than rinse. The staining measured by extent was also Jess with the chlorhexidine gum than the rinse, but the difference was not significant at week 4. At week 8, stain extent was significantly lower in the chlorhexidine gum group than chlorhexidine rinse. In conclusion, the results of this study demonstrate that this chlorhexidine chewing gum used with normal tooth cleaning provides similar adjunctive benefits to oral hygiene and gingival health as a 0.2% chlorhexidine rinse.     

The effect of polyvinyl pyrrolidone on the clinical activity of 0.09% and 0.2% chlorhexidine mouthrinses

BACKGROUND: Previous studies have shown that polyvinyl pyrrolidone (PVP) added to a chlorhexidine rinse reduced extrinsic dental stain but at the expense of a reduction in plaque inhibitory activity. This effect appeared due to a reduction in the effective chlorhexidine dose to levels where dose response studies show plaque inhibition falls off rapidly. The aim of these 2 clinical studies was to determine if PVP could be added to chlorhexidine rinses to maintain efficacy and reduce staining. METHOD: Study 1 involved 42 healthy dentate volunteers and was a blind, randomised, 7 treatment, crossover design balanced for residual effects. The rinses were: 1. 0.09% chlorhexidine to which was added, 2. 1% PVP, 3. 3% PVP, 4. 5% PVP, 5. 7% PVP, 6. Placebo, 7. Essential oil product. Rinses were used 2x on day one of each period after a prophylaxis. Subjects suspended tooth cleaning for 24 h and were then scored for plaque area. Study 2 used the experimental gingivitis model, involved 24 healthy dentate subjects and was a blind, randomised, 3 treatment, crossover design balanced for residual effects. The rinses were 1. 0.2% chlorhexidine, 2. 0.2% chlorhexidine/10% PVP, 3. Placebo. At baseline and the end of each study period subjects were rendered plaque, stain and calculus free, suspended oral hygiene and rinsed 2x per day. Plaque, gingivitis and stain were scored at baseline, 1, 2, and 3 weeks. Calculus was scored at baseline and 3 weeks. RESULTS: Study 1: Buccal plaque scores were significantly lower with all rinses compared to placebo. Also all buccal plaque scores were significantly lower with chlorhexidine and chlorhexidine/PVP rinses compared to the essential oil/phenolic rinse. There were no significant differences between the chlorhexidine rinse and the chlorhexidine/PVP rinses. Analyses for buccal and lingual plaque combined produced, with one exception, the same results for rinse comparisons as for buccal plaque alone. Thus the essential oil/phenolic rinse just failed to reach significance compared to placebo. Study 2: Plaque and gingivitis scores were significantly lower with positive control and test rinses compared to placebo but with no difference between these rinses. Tooth and tongue stain was significantly higher with the positive control and test rinses compared to placebo but not significantly different between these 2 rinses. Calculus scores were not significantly different between the three study rinses. CONCLUSION: Taken with previous data, the balance of evidence does not support PVP as an inhibitor of staining associated with chlorhexidine. These data are further evidence that chlorhexidine oral hygiene products, which, do not or claim not to cause staining, are most probably lacking efficacy.     

The clinical and microbiological effects of a novel acidified sodium chlorite mouthrinse on oral bacterial mucosal infections

Acidified sodium chlorite mouthrinses have been shown to have equivalent anti-plaque activity to those containing chlorhexidine, the current 'gold standard'. In this study, sodium chlorite mouthrinses (ASC) acidified with either malic or gluconic acids were compared to each other and with a chlorhexidine rinse and sterile water for their effect on salivary bacterial counts. Sixteen subjects participated in the study, which had a cross-over Latin square design. In a second study, a sodium chlorite/gluconic acid rinse was compared with chlorhexidine for its clinical and microbiological effects in 36 patients with oral mucosal infections. The sodium chlorite rinses acidified with malic and gluconic acids and the chlorhexidine rinse caused significant reductions in salivary bacterial counts up to 7 h after a single rinse compared with water. There were no significant differences between the three active treatments. In the mucosal infection study, there was a significant reduction in erythema in the chlorhexidine group compared with the ASC group. Patients who received the ASC rinse reported significantly less discomfort following treatment than those receiving the chlorhexidine rinse. Staphylococcus aureus counts were significantly reduced in the group who received the sodium chlorite rinse. There were no other significant differences between the treatments. ASC appears to be an effective alternative to chlorhexidine mouthrinse.     

Matrix metalloproteinase-3 differences in oral and skin fibroblasts

While skin wounds heal by scarring, wounds of oral mucosa show privileged healing with minimal scar formation. Our hypothesis was that phenotypic differences between oral and skin fibroblasts underlie these differences in healing. The aims of this study were to compare MMP-3 expression by oral and skin fibroblasts and investigate a role for MMP-3 in mediating collagen gel contraction. Oral fibroblasts induced significantly greater gel contraction than did paired skin cells. Inhibition of MMP activity significantly inhibited gel contraction by both cell types. Specific inhibition of MMP-3 activity reduced gel contraction by oral, but not skin, fibroblasts. Oral fibroblasts produced significantly higher levels of MMP-3 than did skin fibroblasts at all levels studied. TGF-beta1 and -beta3 isoforms stimulated MMP-3 expression at mRNA, protein, and activity levels by both fibroblast populations. Results suggest that increased MMP-3 production by oral fibroblasts may underlie the differences in wound-healing outcome seen in skin and oral mucosa.     

Comparative antiplaque effectiveness of an essential oil and an amine fluoride/stannous fluoride mouthrinse

The adjunctive use of antimicrobial mouthrinses to help control supragingival plaque and gingivitis has been shown to contribute significantly to patients' daily oral hygiene regimens. This controlled clinical study used an observer-blind, randomized, cross-over design in a 4-day plaque regrowth model to determine the relative efficacies of an essential oil-containing mouthrinse (Listerine Antiseptic) and an amine fluoride/stannous fluoride-containing mouthrinse (Meridol) in inhibiting the development of supragingival plaque. A 0.1% chlorhexidine mouthrinse (Chlorhexamed-Fluid) was used as a positive control, and a 5% hydroalcohol solution was used as a negative control. Dosing for each of the test mouthrinses was based on the manufacturers' label directions. Because the volume and rinse time for each of the test mouthrinses were different, each test mouthrinse had its own negative control group. On day 1 of each test period, subjects received an oral soft and hard tissue examination and a dental prophylaxis to remove all plaque, calculus, and extrinsic stain. Starting the same day, subjects refrained from all mechanical oral hygiene procedures for the next 4 days and rinsed 2x daily under supervision with their randomly-assigned mouthrinse. On day 5, each subject received a plaque assessment as well as an oral examination to assess side effects. Each test period was separated by a 2-week washout period. 23 volunteers with a median age of 26 years completed the study. Compared to the respective placebos, the median percent plaque reductions at 5 days were 23.0%, 12.2%, and 38.2% for the essential oil, amine/stannous fluoride, and chlorhexidine rinses, respectively. The plaque reductions seen in the essential oil and chlorhexidine rinse groups were statistically significant (p < 0.001), while the plaque reduction in the amine/stannous fluoride rinse group was not statistically significant (p > 0.05). Additionally, the essential oil rinse was significantly more effective (p < 0.001) than the amine/stannous fluoride rinse in inhibiting plaque accumulation in this clinical model.