Antimicrobial and Antibiofilm Effect of Hydrogel with Origanum vulgare on Culture of Streptococcus mutans and Streptococcus sobrinus / Efecto Antimicrobiano y Antibiofilm de Hidrogel a Base de Origanum vulgare sobre Cultivo de Streptococcus mutans y Streptococcus sobrinus

The oral cavity is an ecosystem that provides ideal conditions for the growth of bacteria, the Streptococcus genus is important for the formation of biofilms that lead to the development of dental caries, which affects the population worldwide. The world health organization encourages the use of plants thanks to its various therapeutic actions. Origanum vulgare L. (oregano), is an aromatic plant with medicinal and culinary properties. The objective of this study was to investigate the in vitro antimicrobial and antibiofilm activity of the ethanolic extract of oregano, against the growth of Streptococcus mutans and Streptococcus sobrinus ATCC. Leaves of the plant were obtained and the ethanolic extract was made by maceration. Antimicrobial activity was evaluated using the Kirby-Bauer method and compared with 2% chlorhexidine, subsequently the extract was incorporated into a hydrogel and its effect on biofilm formation was assessed by fluorescence microscopy and the main compounds were identified. present in the extratco. The study revealed that the extract presented antimicrobial effect against both strains and at 2% it showed high antimicrobial action compared to chlorhexidine at the same concentration, with average inhibition halos of 26.3 mm and 19 mm for each microorganism analyzed, (p < 0.05). Likewise, the hydrogel prepared with 2% extract significantly eliminated the preformed Streptococcus biofilm, at 24 hours of exposure, due to the presence of a variety of chemical groups, such as sterols, triterpenes, flavonoids, flavanones, flavanonol s, lactones. sesquiterpenic, tannins and coumarins. The oregano extract presented high antimicrobial action for both species, with a greater effect towards Streptococcus mutans and an interesting antibiofilm action; These results show the importance of exploring treatment alternatives of plant origin, to be considered as interesting complementary aids in dental therapy.

La cavidad oral es un ecosistema que proporciona condiciones ideales para el crecimiento de bacterias, el género Streptococcus es importante para la formación de biopelículas que conducen al desarrollo de caries dental, que afecta a la población a nivel mundial. La organización mundial de la salud, fomenta el uso de plantas gracias a sus diversas acciones terapéuticas. Origanum vulgare L. (orégano), es una planta aromática con propiedades medicinales y culinarias. El objetivo de este estudio fue investigar la actividad antimicrobiana y antibiofilm in vitro del extracto etanólico de oregano, contra el crecimiento de Streptococcus mutans y Streptococcus sobrinus ATCC. Se obtuvierón hojas de la planta y se realizó el extracto etanólico mediante maceración. La actividad antimicrobiana se evaluó mediante el método de Kirby-Bauer y se comparó con la clorhexidina al 2 %, posteriormente se incorporó el extracto en un hydrogel y se valoró su efecto sobre la formación del biofilm mediante microscopía de fluorescencia y se identificó los principales compuestos presentes en el extratco. El estudio reveló que el extracto presentó efecto antimicrobiano contra ambas cepas y al 2 % mostró alta acción antimicrobiana en comparación con la clorhexidina a la misma concentración, con halos de inhibición promedio de 26.3 mm y de 19 mm para cada microorganismo analizado, (p < 0.05). Así mismo, el hidrogel preparado con extracto al 2 %, eliminó significativamente la biopelícula preformada de Streptococcus, a las 24 horas de exposición, debido a la presencia de una variedad de grupos químicos, como esteroles, triterpenos, flavonoides, flavanonas, flavanonoles, lactonas sesquiterpénicas, taninos y cumarinas. El extracto de orégano presentó alta acción antimicrobiana para ambas especies, con mayor efecto hacia el Streptococcus mutans y una acción antibiofilm interesante; estos resultados muestran la importancia de explorar en alternativas de tratamiento de origen vegetal, para considerarse como auxiliares complementarios interesantes en la terapia dental.

Cariogenic potential of oral nutritional supplements measured by intraoral plaque pH telemetry.

BACKGROUND & AIMS: Oral nutritional supplements (ONS) administered to malnourished elders and other patients contain high-levels of carbohydrates that could be a potential risk factor for dental caries. This study aimed to evaluate the cariogenic potentials of ONS using intraoral plaque telemetry. METHODS: Ten ONS were tested on five healthy volunteers (mean age: 76.8 ± 9.15 years). Participants were requested to refrain from performing oral hygiene 3-7 days prior to testing. The pH-value below the dental plaque on the tooth was measured while the ONS was being consumed. After neutralizing the participant's saliva, a control solution (10% sucrose) was administered and telemetry measurements were repeated. Mean relative cariogenicity (RC) was calculated for each ONS. ANOVA and post hoc tests were used for statistical analyses (p < 0.05). RESULTS: All ten ONS were potentially cariogenic on enamel with an overall RC of 0.519 ± 0.35 (Range: Min = 0.31 ± 0.16; Max = 1.00 ± 0.34). RC differed significantly between the ONS (p = 0.002). RC was lower in ONS that contained high-protein (p = 0.018). RC was not influenced by other factors such as readily consumable (p = 0.102), flavor (p = 0.869), consistency (p = 0.126), fiber containing (p = 0.134), style (p = 0.112), and age of plaque (p = 0.339). CONCLUSIONS: The ONS administered to elders and malnourished patients are potentially cariogenic. It is imperative that the administration of ONS must be based on individual needs to potentiate a maximum benefit. Wherever possible, an attempt to limit the use of high-carbohydrate containing ONS must be practiced along with the adoption of suitable preventive measures to arrest the development and progression of caries.

CPP-ACP: Effect on Dental Plaque Acidity after Water Rinsing Following Topical Fluoride Therapy.

OBJECTIVES: There is some evidence that water rinsing immediately after topical fluoride therapy has the potential to reduce the effectiveness of fluoride. The aim was to determine if covering fluoridated teeth with a layer of mousse containing CPP-ACP could prevent the adverse effect of rinsing on fluoride and consequently its buffering effect on dental plaque pH during cariogenic challenge. STUDY DESIGN: This randomized, controlled, crossover, in situ study was conducted on 25 participants. The participants were subjected to acidulated phosphate fluoride (APF) application followed by five treatment protocols: (1) water rinsing after 30 minutes (APF-30) or (2) immediate water rinsing (APF-0); (3) using CPP-ACP immediately before water rinsing (F-CPP-ACP); and two control groups: (4) no fluoride therapy (No-F) and (5) using CPP-ACP and immediate water rinsing (CPP-ACP-0). After 48 hours, teeth were rinsed with 10% sucrose solution and plaque pH was measured before and after 5, 10, 15, 20 and 30 minutes. RESULTS: The least pH changes, the lowest pH drop, and the quickest pH recovery were found in the APF-30 and F-CPP-ACP groups. APF-0 ranked in the middle and the highest values were in the control groups. CONCLUSIONS: The results show that in the case using CPP-ACP on fluoridated teeth, water rinsing immediately after topical fluoride therapy did not seem to influence the inhibitory effect of fluoride on plaque acidity.

Are there metallic traces in black extrinsic dental stain?

OBJECTIVE: The detection of ferric ions in samples of black extrinsic dental stain led to the idea that it is comprised of insoluble ferric compounds. The present study examined the chemical composition of black extrinsic dental stain. METHOD AND MATERIALS: Plaque was collected from 17 children with black extrinsic dental stain (study group A) and from 15 children without black extrinsic stain (control group), using sterile graphite curettes; and from 4 children with black extrinsic stain (study group B), using a standard sterile metal curette. Samples were analyzed with a scanning electron microscope (SEM) and subjected to quantitative chemical analysis (energy dispersive spectrometry). RESULTS: Except for calcium and phosphorus levels, no significant differences were found between the chemical composition of black extrinsic dental stain and dental plaque. Metallic ions were not detected in samples collected with a graphite curette (study group A), but were detected in samples collected with a metal curette (study group B). CONCLUSION: Metallic ions do not seem to be the origin of black extrinsic dental stain. Previous reports of the presence of metallic ions are probably due to contamination of the samples by the collection method.

Effect of a third application of toothpastes (1450 and 5000 ppm F), including a 'massage' method on fluoride retention and pH drop in plaque.

OBJECTIVE: The aim was to investigate fluoride (F) retention in plaque, saliva and pH drop in plaque using high-F toothpaste (5000 ppm F) or standard toothpaste (1450 ppm F) twice a day or 3-times a day. A method using the toothpaste as a 'lotion' and massaging the buccal surfaces with the fingertip was also evaluated. MATERIALS AND METHODS: The investigation had a randomized, single-blinded, cross-over design and 16 subjects participated in six brushing regimes: (1) 5000 ppm F; twice a day, (2) 5000 ppm; 3-times/day, (3) 5000 ppm; twice a day, plus the 'massage' method once a day, (4) 1450 ppm F; twice a day, (5) 1450 ppm; 3-times/day and (6) 1450 ppm; twice a day, plus the 'massage' method once a day. The outcome measure was F retention in plaque, saliva and the plaque-pH change after a sucrose rinse. RESULTS: The highest F concentration was found using high-F toothpaste (No 1-3) and differed significantly from those with 1450 ppm (No 4-6). Brushing with high-F toothpaste 3-times a day (No 2) resulted in a 3.6-times higher F saliva value compared with standard toothpaste twice a day (No 4) (p < 0.001). Increasing the frequency of application, from twice to 3-times a day, increased the F retention in plaque significantly when the two methods for application 3-times a day were pooled (p < 0.05). Brushing with 5000 and 1450 ppm toothpastes twice a day plus the 'massage' once a day resulted in the same F concentration in saliva and plaque as brushing 3-times a day with the same paste. CONCLUSION: A third application of toothpaste is increasing the F retention and toothpaste as a 'lotion' and massaging the buccal surfaces with the fingertip may be a simple and inexpensive way of delivering F a third time during the day.

Remineralization agents - new and effective or just marketing hype?

This is a review of the need for better remineralization and of the status of calcium-based remineralizing agents for use in anti-caries toothpastes. Use of fluoride toothpastes has markedly reduced caries. However, the decline may be over or in reverse. There is a limit to what fluoride alone can do; complementary agents are needed. Using plaque as a reservoir for calcium-based agents holds promise. Plaque fluid is already supersaturated with respect to relevant calcium phosphates at neutral pH; extra calcium may lead to surface-blocking and sub-optimal lesion consolidation. However, at cariogenic pH, lesions may be more porous to the ingress of mineral, leading to fuller consolidation, and controlled release of calcium should reduce undersaturation with respect to enamel and accelerate deposition of fluorhydroxyapatite. Clinical data to validate in vitro screening models are scarce. Direct progression to in situ models may often be appropriate. The spectrum of lesion types, from softening to relatively advanced subsurface, and lesion activity should be considered. Far from being 'marketing hype', progress with calcium-based remineralizing agents is both encouraging and scientifically sound. Clinical evidence exists for the efficacy of some agents, but further unequivocal clinical data are needed before these agents might be considered 'effective' when delivered from toothpaste.

Effect of consuming different dairy products on calcium, phosphorus and pH levels of human dental plaque: a comparative study.

AIM: To determine the calcium, phosphorus and pH levels of human dental plaque after consuming different dairy products. METHODS: 68 students (34 with caries and 34 caries-free) aged 17-20 years from a private dental college, Moradabad city, who agreed to refrain from oral hygiene procedures for 48 hours were selected for the study. Calcium and phosphorus levels of harvested dental plaque were measured using an electrolyte analyser while plaque pH was measured using a digital pH meter after consuming different dairy products (cheese, milk, yogurt) and compared with the control (paraffin) group. RESULTS: Cheese and yogurt groups showed a statistically significant rise in mean plaque concentrations of calcium and phosphorus, whereas milk and control groups showed the least rise in plaque concentrations for both caries-active and caries-free subjects. Plaque pH showed a stronger correlation with plaque calcium and phosphorus concentrations in both caries-active and caries-free subjects. CONCLUSION: Cheese and yogurt without any added sugar (sucrose) are non-cariogenic and to some extent cariostatic as they increase calcium and phosphorus concentration in dental plaque. Dairy products without added sugar can be recommended as after meal desserts, especially to school children, which would help to reduce the incidence of dental caries.

Calcium binding to S. mutans grown in the presence or absence of sucrose.

Sucrose is the most cariogenic dietary carbohydrate because it is a substrate for insoluble extracellular polysaccharide (IEPS) production in dental biofilms, which can proportionally decrease bacterial density and, consequently, the number of biofilm calcium (Ca) binding sites. Ca bound to bacterial cell walls can be released into the biofilm fluid during a cariogenic challenge, reducing the driving force for mineral dissolution provoked by the pH drop. Thus, we investigated the effect of an IEPS-rich extracellular matrix on bacterial Ca binding after treatment with Ca solutions. Streptococcus mutans Ingbritt 1600 was cultivated in culture broths supplemented with 1.0% sucrose or 0.5% glucose + 0.5% fructose. The IEPS concentration in bacterial pellets was determined after alkaline extraction. Bacterial pellets were treated with 1 mM or 10 mM Ca++ solutions at 37ºC for 10 to 60 min. Ca binding to bacterial pellets, determined after acid extraction using the Arsenazo III reagent, was fast and concentration dependent. Although the IEPS concentration was approximately ten times higher in bacterial pellets cultivated in sucrose as compared to its monossaccharides, bound Ca concentration after Ca treatment was similar in both conditions. These results suggest that IEPS may not influence the amount of Ca bound to reservoirs of dental biofilms.

Calcium binding to S. mutans grown in the presence or absence of sucrose

Sucrose is the most cariogenic dietary carbohydrate because it is a substrate for insoluble extracellular polysaccharide (IEPS) production in dental biofilms, which can proportionally decrease bacterial density and, consequently, the number of biofilm calcium (Ca) binding sites. Ca bound to bacterial cell walls can be released into the biofilm fluid during a cariogenic challenge, reducing the driving force for mineral dissolution provoked by the pH drop. Thus, we investigated the effect of an IEPS-rich extracellular matrix on bacterial Ca binding after treatment with Ca solutions. Streptococcus mutans Ingbritt 1600 was cultivated in culture broths supplemented with 1.0% sucrose or 0.5% glucose + 0.5% fructose. The IEPS concentration in bacterial pellets was determined after alkaline extraction. Bacterial pellets were treated with 1 mM or 10 mM Ca++ solutions at 37ºC for 10 to 60 min. Ca binding to bacterial pellets, determined after acid extraction using the Arsenazo III reagent, was fast and concentration dependent. Although the IEPS concentration was approximately ten times higher in bacterial pellets cultivated in sucrose as compared to its monossaccharides, bound Ca concentration after Ca treatment was similar in both conditions. These results suggest that IEPS may not influence the amount of Ca bound to reservoirs of dental biofilms.

Effect of a sugar-free chewing gum containing magnolia bark extract on different variables related to caries and gingivitis: a randomized controlled intervention trial.

The effect of magnolia bark extract (MBE) on different variables related to caries and gingivitis administered daily through a sugar-free chewing gum was evaluated. The study was performed with healthy adult volunteers at high risk for caries as a randomized double-blind interventional study. 120 subjects with a salivary mutans streptococci (MS) concentration ≥10(5) CFU/ml and presence of bleeding on probing >25% were enrolled and divided into three groups: magnolia, xylitol and control. The study design included examinations at baseline, after 7 days, after 30 days of gum use and 7 days after the end of gum use. Plaque pH was assessed using the strip method following a sucrose challenge. Area under the curve (AUC(5.7) and AUC(6.2)) was recorded. Whole saliva was collected and the number of salivary MS (CFU/ml) was counted. Bleeding on probing was recorded as a proxy of dental plaque. Data were analyzed using ANOVA repeated measures. Magnolia gum significantly reduced plaque acidogenicity, MS salivary concentration and gingival bleeding compared to xylitol and control gums. Subjects from the magnolia and xylitol groups showed both MS concentration (p = 0.01 and 0.06, respectively) and AUC(5.7) (p = 0.01 and 0.04, respectively) to be significantly lower compared to baseline. Thirty-day use of a chewing gum containing MBE showed beneficial effects on oral health, including reduction of salivary MS, plaque acidogenicity and bleeding on probing.

The effects of fluoride and mineralising treatments on plaque microcosm Ca, P and F, pH responses and cariogenicity.

OBJECTIVE: To investigate the effects of fluoride (F), calcium-phosphate-monofluorophosphate-urea (CPMU) mineralising solution, and casein on plaque pH and calcium (Ca), phosphate (P) and F content, and the ability of plaque to induce carious lesions in enamel. METHODS: Plaque microcosms were cultured in cariogenic growth conditions on enamel specimens for 28d in a "multiplaque artificial mouth". The plaques were supplied 5 times daily with 10% sucrose (1.5 ml over 6 min) over a 12h period followed by a 12h rest period. Duplicate plaques were pulsed with 0, 1000, 3000 and 5000 ppm F (1.5 ml over 6 min) or 2% w/v casein (1.25 ml over 30 min) twice daily. One of each pair was also pulsed with CPMU (1.5 ml over 6 min). Plaque pH was monitored during growth. After 28 days' culture, plaque Ca, P and F levels were quantified and lesion depth in enamel was measured by backscattered electron SEM. RESULTS: F pulses raised the plaque pH, which was otherwise below 4 during sucrose pulsing, while CPMU hastened and raised the recovery pH. Plaque Ca, P and F levels substantially increased with increasing concentrations of applied F, particularly in the presence of CPMU (P < 0.01). In the absence of either F or CPMU, enamel lesions were formed with extensive enamel loss. CONCLUSIONS: CPMU and F supplied to plaque microcosms substantially reduce plaque cariogenicity to enamel under highly cariogenic experimental conditions. This was associated with an increase in plaque pH, plaque F and Ca levels.

Relationship between caries and dental plaque composition.

PURPOSE: To evaluate the relationship between dental caries and the biochemical composition of dental plaque and to determine the effect of a 10% sucrose solution on the biochemical structure of dental plaque in children. METHODS: 60 children grouped according to caries status took part in this study [Caries-free (CF), DMFS=0, df-s = 0; Caries-positive (CP), DMFS > or =10, df-s > or =10]. Dental plaque samples were collected before (baseline) and at 3 and 30 minutes after a 1-minute rinse with 10% sucrose. Fluoride (F), calcium (Ca), and inorganic phosphorus (Pi) levels were determined using ion chromatography, and insoluble polysaccharide (IEPS) concentrations were determined using colorimetric analysis. RESULTS: Although the mean baseline Ca and Pi levels in plaque were higher in the CF group than in the CP group, these differences were not statistically significant. Baseline IEPS levels were significantly higher in the CP group than in the CF group. Following exposure to sucrose, plaque F, Ca and Pi concentrations decreased significantly in both groups. However, insoluble polysaccharide concentrations increased significantly in the CF group only.

A pilot study of the role of green tea use on oral health.

INTRODUCTION: An increasing number of people all around the world are turning to the nature by using the natural herbal products in both prophylaxes and treatment of different diseases. Green tea with active chemical ingredients posses diverse pharmacological properties that include anti-inflammatory, anticariogenic, antioxidant and antibacterial effects. AIMS: To assess the possible protective properties of green tea on oral health. METHODS: The researchers used the following measurements: Streptococcus mutans count in saliva and plaque, Salivary and plaque pH values, Gingival Bleeding Index (GBI). The above-mentioned measurements were applied to a sample consists of 25 subjects before and after rinsing with green tea for 5 min (short-term study). While, S. mutans count for saliva and plaque and GBI measurements, this experimental intervention study was carried out in the El-Azhar University dental clinic. RESULTS: The results of this study showed that there was a statistically significant difference among subjects pre- and post-rinsing with 2% green tea for 5 min concerning S. mutans count in saliva and plaque, salivary and plaque pH values and GBI. CONCLUSION: This study supports the effectiveness of local application of green tea as antibacterial and anticariogenic material as it decreases the acidity of the saliva and plaque, so it is a cost-effective caries prevention measures especially in developing countries.

Morphological and chemical characterization of tooth enamel exposed to alkaline agents.

OBJECTIVES: In this study, morphological and chemical changes in teeth enamel exposed to alkaline agents, with or without surfactants, have been investigated. In addition, chemical effects of the organic surface layer, i.e. plaque and pellicle, were also investigated. METHODS: The present study was conducted using several techniques: Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). RESULTS: From XPS-measurements, it was found that exposure to alkaline solutions resulted in a massive removal of carbon from the tooth surface, and that the addition of surfactants increased the rate under present conditions. Based on the results from the FTIR-analysis, no substitution reactions between phosphate, carbonate and hydroxide ions in the enamel apatite could be detected. From a minor SEM-analysis, degradation and loss of substance of the enamel surface was found for the exposed samples. From XRD-analysis, no changes in crystallinity of the enamel apatite could be found between the samples. CONCLUSIONS: The findings in this study show that exposure to alkaline solutions results in a degradation of enamel surfaces very dissimilar from acidic erosion. No significant erosion or chemical substitution of the apatite crystals themselves could be discerned. However, significant loss of organic carbon at the enamel surface was found in all exposed samples. The degradation of the protective organic layer at the enamel surface may profoundly increase the risk for caries and dental erosion from acidic foods and beverages.

Effects of mouthrinses containing essential oils and alcohol-free chlorhexidine on human plaque acidogenicity.

The aim of this in vivo study was to evaluate the effect of two antimicrobial mouthrinses on dental plaque acidogenicity after a sucrose challenge. Twenty subjects, with a mean age of 59 years, participated in a double-blind intraindividual randomized study. Three mouthrinses were used in 16-day rinsing periods in addition to their regular mechanical oral hygiene: a solution with essential oils (EO), solution with alcohol-free chlorhexidine (CHX) and water (negative control). The three test periods were separated by 3-month washout periods. Changes in plaque acidogenicity were evaluated after a sucrose challenge at day 0 (baseline) and at day 17 of each mouthrinse period using the microtouch method. Both CHX and EO resulted at day 17 in statistically significant less attenuated pH falls compared to the water rinse. The CHX mouthrinse resulted in the least pronounced pH values compared with EO (ns) during the whole 30-min period. When calculated as area under the curve (AUC), significantly lower values (AUC(6.2) ) were found for CHX and EO at day 17 compared to day 0. A significant difference for AUC(6.2) between CHX and water was found at day 17. No statistically significant differences were found for any of the comparisons with AUC(5.7). The results from this study indicate that both the essential oils and the alcohol-free chlorhexidine reduced plaque acidogenicity after a sucrose challenge. Large interindividual variations were observed.

Effect on de novo plaque formation of rinsing with toothpaste slurries and water solutions with a high fluoride concentration (5,000 ppm).

The aim of this study was to evaluate the effect, on de novo plaque formation, of rinsing with toothpaste slurries and water solutions containing a high concentration of fluoride (F). Sixteen subjects rinsed three times per day for 4 d with dentifrice slurries containing 5,000, 1,500, and 500 ppm F, while 12 subjects rinsed with water solutions containing 5,000, 1,500, 500, and 0 ppm F, and 1.5% sodium lauryl sulphate (SLS). Plaque was scored [using the Quigley & Hein index (QHI)] after each 4-d period. Plaque samples for F analysis were collected. Significantly less plaque was scored for the dentifrice slurry containing 5,000 ppm F (buccal and all surfaces) and for 1.5% SLS (buccal surfaces). The differences in plaque scores between dentifrice containing 5,000 and 1,500 ppm F were 19% for all surfaces and 33% for buccal surfaces. The difference between the water solutions containing 1.5% SLS and 1,500 ppm F for buccal surfaces was 23%; the corresponding difference for 5,000 ppm F was 17%. The dentifrice slurry containing 5,000 ppm F accumulated 56% more F in plaque. The combination of high levels of F and SLS in dentifrice reduces de novo plaque formation and increases the accumulation of F in plaque after 4 d.

Anticalculus effect of a triclosan mouthwash containing phytate: a double-blind, randomized, three-period crossover trial.

BACKGROUND AND OBJECTIVE: Dental calculus occurs as a consequence of supersaturation of saliva with respect to calcium phosphates. This mineralization of dental plaque can be delayed by the presence of crystallization inhibitors, such as pyrophosphate or bisphosphonates. Phytate inhibits brushite and hydroxyapatite crystallization and has the potential to prevent dental calculi formation. The aim of the present study was to examine the effects of phytate and zinc, administered in a mouthwash solution, to prevent the formation of dental calculus. MATERIAL AND METHODS: Healthy dental plaque-forming volunteers (n = 25) took part in a randomized, double-blind, three-period crossover clinical study to assess the efficacy of a phytate-containing mouthwash in relation to control and placebo effects. Subjects rinsed their mouths for 1 min, twice each day, with 20 mL of the test solution, without ingestion. Mouthwash efficacy was assessed through quantification of the amounts of calcium, phosphorus and magnesium present in the residues obtained by dental cleaning, performed by a single trained examiner. RESULTS: A good correlation was found among total calcium, magnesium and phosphorus in calcified dental plaque residues, indicating that any of these variables is adequate for evaluating the reduction of plaque crystallization as calcium phosphate. A statistically significant decrease in total calcium, magnesium and phosphorus was found in the phytate-treatment period compared with control and placebo periods, demonstrating the efficacy of the proposed treatment in reducing dental calculus formation. CONCLUSION: The high efficacy of phytate in reducing dental calculus formation suggests that this substance may be an effective treatment for preventing the development of calculus deposits.

Effect of a calcium glycerophosphate fluoride dentifrice formulation on enamel demineralization in situ.

PURPOSE: To evaluate in situ the effect and mechanisms involved in the anticariogenic effect of a calcium glycerophosphate fluoride dentifrice. METHODS: In a double-blind, crossover design, a non-F dentifrice (negative control), a F dentifrice and a F dentifrice containing 0.13% CaGP were compared regarding the inhibition of enamel demineralization. Both F dentifrices contained 1500 microg F/g (w/w) as sodium monofluorophosphate (MFP). Bovine enamel blocks were mounted in contact with a S. mutans test plaque, in palatal appliances worn by 10 volunteers. 30 minutes after treatment with the dentifrices, a sucrose rinse was performed and enamel demineralization was assessed after an additional 45 minutes. RESULTS: No significant difference was observed among groups in the calcium and inorganic phosphate concentrations in the fluid phase of the test plaque 30 minutes after the dentifrice use (P > 0.05), but F concentration was significantly higher for both F dentifrices (P < 0.05). Also, the dentifrices did not differ regarding the pH before or 5 minutes after the sugar challenge (P > 0.05). A higher mineral loss was observed for the non-F dentifrice group (P < 0.05), but no significant difference was observed between the F dentifrices containing CaGP or not (P > 0.05). Using this in situ model, the findings suggested that CaGP at the concentration tested did not enhance the inhibition of enamel demineralization promoted by F dentifrice.

Hop polyphenols suppress production of water-insoluble glucan by Streptococcus mutans and dental plaque growth in vivo.

OBJECTIVE: This study determined the effect of Hop polyphenols (HPP) on water-insoluble glucan (WIG), which is a major component of dental plaque along with microorganisms, and the effect of HPP-containing tablets on the growth of dental plaque. METHODS: The effects of HPP on Streptococcus mutans MT8148 were determined. HPP concentrations employed in this study were 0% (as the HPP control), 0.001%, 0.01%, 0.1%, and 0.5%. The average result of six independent experiments was obtained at each concentration of HPP. Suppression of plaque formation in vivo was examined by a clinical trial that was designed as a randomized, single-blind, three-treatment study using 28 healthy subjects. The subjects used either 20 mg or seven mg HPP-containing tablets representing high and low dosages, respectively. The composition of each tablet was similar, except for the level of HPP; the control tablet had none. For the treatment period, subjects took one tablet seven times a day (before breakfast, after each meal, between meals, and at bedtime) for three days. The tablets were dissolved in the mouth and naturally swallowed. Plaque levels were then assessed for the subjects in the three groups. RESULTS: In vitro, after 24-hour incubation, 0.5% HPP significantly reduced the growth of S. mutans compared to the control (p < 0.01). After 18-hour incubation, HPP at 0.1% and 0.5% significantly reduced lactic acid production (p < 0.05 and p < 0.001, respectively), and HPP at 0.01%, 0.1%, and 0.5% also suppressed WIG production (p < 0.01, p < 0.001 and p < 0.001, respectively). In vivo, the effect of HPP-containing tablets (seven times a day) on three-day dental plaque regrowth was assessed by the plaque scoring system (PSS). The high-dosage group using 20 mg HPP tablets exhibited a reduction in PSS (1.37 +/- 0.48 vs. 2.41 +/- 1.15 in the control group, p < 0.05). CONCLUSION: It was concluded that HPP tablets might be a significant means of delivering HPP onto tooth surfaces to prevent dental plaque formation.