Sterility maintenance of reused disposable paper/plastic sterilization pouches in actual clinical practice.

Paper/plastic sterilization pouches are commonly used packaging material for steam sterilization. Reuse of these pouches is a general practice in Thailand despite a single-use recommendation. This study aimed to determine microbial contamination after reusing paper/plastic sterilization pouches in a dental clinic and storage in a closed environment for 6 months. Three hundred and twenty pouches underwent 3 times of clinical use in terms of packaging, autoclave sterilization, handling, and unpacking. A mouth mirror was packed in each pouch to be used in a clinic. After each use, a pouch would be carefully inspected for reusability and undergone packaging, sterilization, handling again. In all steps, sterilization monitoring was rigorously applied. After 3 times of use, a piece of filter paper was placed inside each pouch (instead of a mouth mirror), the pouch was autoclaved and stored in a closed environment for 6 months. Then the filter paper was retrieved for microbial cultivation. A negative control group comprised new pouches containing filter paper without storage and a positive control group comprised pouches with impaired integrity. All samples in both the reuse and the negative control groups had no microbial contamination. All samples in the positive control group showed contamination. These results suggested that reusing paper/plastic sterilization pouches could be a safe practice provided careful monitoring and inspection were employed.

Effects of resterilization and storage time on sterility of paper/plastic pouches.

OBJECTIVES: Paper/plastic pouches are widely used packaging materials for autoclaving medical and dental equipment. Although these pouches are recommended for single use, they are generally reused in Thailand. This study aimed to determine the ability of paper/plastic pouches to maintain sterility after multiple sterilization processes and stored in a closed environment for up to 6 months. MATERIALS AND METHODS: A total of 6720 paper/plastic pouches were divided into four experimental groups: new pouches, 1 time, 3 times, and 5 times resterilized pouches. A piece of filter paper was placed inside each pouch, and the pouch was sealed, sterilized, and stored for up to 6 months. At the end of each storage period, the pouch was opened, and the filter paper was transferred to culture broth for microbial cultivation to determine sterility. Negative and positive controls were also used to validate the procedures. RESULTS: All filter papers in the experimental groups, as well as the negative control group, remained sterile for up to 6 months of storage in a closed environment. On the contrary, all filter papers in the positive control group showed microbial contamination. CONCLUSIONS: In a closed storage condition, the paper/plastic pouches that passed multiple sterilization processes (up to 5 times resterilization) still maintained good barrier efficacy and remained sterile for up to 6 months.

Veillonella infantium sp. nov., an anaerobic, Gram-stain-negative coccus isolated from tongue biofilm of a Thai child.

A strain of a novel anaerobic, Gram-stain-negative coccus was isolated from the tongue biofilm of a Thai child. This strain was shown, at the phenotypic level and based on 16S rRNA gene sequencing, to be a member of the genus Veillonella. Comparative analysis of the 16S rRNA, dnaK and rpoB gene sequences indicated that phylogenetically the strain comprised a distinct novel branch within the genus Veillonella. The novel strain showed 99.8, 95.1 and 95.9 % similarity to partial 16S rRNA, dnaK and rpoB gene sequences, respectively, to the type strains of the two most closely related species, Veillonelladispar ATCC 17748T and Veillonellatobetsuensis ATCC BAA-2400T. The novel strain could be discriminated from previously reported species of the genus Veillonella based on partial dnaK and rpoB gene sequencing and average nucleotide identity values. The major acid end-product produced by this strain was acetic acid under anaerobic conditions in trypticase-yeast extract-haemin with 1 % (w/v) glucose or fructose medium. Lactate was fermented to acetic acid and propionic acid. Based on these observations, this strain represents a novel species, for which the name Veillonella infantium sp. nov. is proposed. The type strain is T11011-4T (=JCM 31738T=TSD-88T).

Exploring the salivary microbiome of children stratified by the oral hygiene index.

Poor oral hygiene often leads to chronic diseases such as periodontitis and dental caries resulting in substantial economic costs and diminished quality of life in not only adults but also in children. In this study, the salivary microbiome was characterized in a group of children stratified by the Simplified Oral Hygiene Index (OHI-S). Illumina MiSeq high-throughput sequencing based on the 16S rRNA was utilized to analyze 90 salivary samples (24 Good, 31 Moderate and 35 Poor oral hygiene) from a cohort of Thai children. A total of 38,521 OTUs (Operational Taxonomic Units) with a 97% similarity were characterized in all of the salivary samples. Twenty taxonomic groups (Seventeen genera, two families and one class; Streptococcus, Veillonella, Gemellaceae, Prevotella, Rothia, Porphyromonas, Granulicatella, Actinomyces, TM-7-3, Leptotrichia, Haemophilus, Selenomonas, Neisseria, Megasphaera, Capnocytophaga, Oribacterium, Abiotrophia, Lachnospiraceae, Peptostreptococcus, and Atopobium) were found in all subjects and constituted 94.5-96.5% of the microbiome. Of these twenty genera, the proportion of Streptococcus decreased while Veillonella increased with poor oral hygiene status (P < 0.05). Furthermore, an unassigned species of Veillonella, Veillonella dispar and Veillonella parvula tended to be elevated in the Poor oral hygiene group. This is the first study demonstrating an important association between increase of Veillonella and poor oral hygiene status in children. However, further studies are required to identify the majority of Veillonella at species level in salivary microbiome of the Poor oral hygiene group.

SiO2-nanocomposite film coating of CAD/CAM composite resin blocks improves surface hardness and reduces susceptibility to bacterial adhesion.

Composite resin blocks for computer-aided design/computer-aided manufacturing (CAD/CAM) applications have recently become available. However, CAD/CAM composite resins have lower wear resistance and accumulate more plaque than CAD/CAM ceramic materials. We assessed the effects of SiO2-nanocomposite film coating of four types of CAD/CAM composite resin blocks: Cerasmart, Katana Avencia block, Lava Ultimate, and Block HC on surface hardness and bacterial attachment. All composite blocks with coating demonstrated significantly greater Vickers hardness, reduced surface roughness, and greater hydrophobicity than those without coating. Adhesion of Streptococcus mutans to the coated specimens was significantly less than those for the uncoated specimens. These reduced levels of bacterial adherence on the coated surface were still evident after treatment with saliva. Surface modification by SiO2-nanocomposite film coating has potential to improve wear resistance and susceptibility to plaque accumulation of CAD/CAM composite resin restorations.

Cell-Free DNA Profile in Peri-Implant Skin Exudate of Craniofacial Implants with Various Degrees of Inflammation: A Pilot Study.

PURPOSE: To profile human ß-globin gene fragment lengths from cell-free DNA in peri-implant skin exudate of craniofacial implants with various degrees of soft tissue inflammation. MATERIALS AND METHODS: Fifteen participants (30 implants) were recruited for this study. All participants were recalled for three consecutive visits at days 0, 14, and 28. During each visit, the soft tissue condition at the skin-abutment interface of each craniofacial implant was graded by Holgers score, and the implant stability quotient (ISQ) values of the implants were also measured. Peri-implant skin exudate specimens were collected and centrifuged to obtain cell-free DNA. Conventional polymerase chain reaction was used to assess DNA fragment lengths by amplifying five polymerase chain reaction amplicon sizes from 110-base pairs (bp) to 2-kilobase pairs (kbp) of human ß-globin gene. The longest polymerase chain reaction amplicon size found in each specimen was then recorded. RESULTS: No significant differences in the ISQ values of the implants (P > .05) were noted during the study period. In each recall visit, a correlation was observed between Holgers score and polymerase chain reaction amplicon sizes (P < .001). A gradual decrease in both parameters was also noted following the treatment protocol (P < .05). From the 90 exudate specimens obtained from all the observation visits, 1-kbp amplicon sizes were usually found in the group with Holgers score 1 (47 of 52 specimens); 2-kbp amplicon sizes were often found in the group with Holgers score 2 (22 of 32 specimens) and predominantly found in the group with Holgers score 3 (5 of 6 specimens). CONCLUSION: The 1-kbp amplicon sizes can serve as a marker for mild clinical inflammation of peri-implant skin. Similarly, 2-kbp amplicon sizes may be used as a prognostic marker for denoting greater cell destruction and inflammation, which indicate a greater risk of severe inflammation. However, further studies are required to support these findings.

Identification of Veillonella Species in the Tongue Biofilm by Using a Novel One-Step Polymerase Chain Reaction Method.

Six Veillonella species have been frequently isolated from human oral cavities including infectious sites. Recently, it was reported that diet, smoking, and possibly socioeconomic status can influence the bacterial profile in oral cavities. In addition, oral hygiene habits may also influence oral microbiota in terms of both numbers and diversity of microorganisms. In this study, the identification of Veillonella species in tongue biofilms of Thai children, divided into three groups dependent on their status of oral hygiene. For this, we used a novel one-step PCR method with species-specific primer sets based on sequences of the rpoB gene. As shown in the results, the number of isolates of Veillonella species was 101 strains from only 10 of 89 subjects. However, the total number of bacteria was high for all subjects. Since it was reported in previous studies that Veillonella species were easy to isolate in human tongue biofilms at high numbers, the results obtained in this study may suggest country- or age-specific differences. Moreover, Veillonella species were detected predominantly in subjects who had poor oral hygiene compared to those with good or moderate oral hygiene. From these results, there is a possibility that Veillonella species may be an index of oral hygiene status. Furthermore, V. rogosae was a predominant species in tongue biofilms of Thai children, whereas V. parvula and V. denticariosi were not isolated at all. These characteristics of the distribution and frequency of Veillonella species are similar to those reported in previous studies. Although further studies are needed in other countries, in this study, a successful novel one-step PCR method was established to detect Veillonella species in human oral cavities easily and effectively. Furthermore, this is the first report investigating the distribution and frequency of Veillonella species in tongue biofilms of Thai children.

Evaluation of host ß-globin gene fragment lengths in peri-implant crevicular fluid during the wound healing process: a pilot study.

PURPOSE: To evaluate the host ß-globin gene fragment lengths in the cell-free peri-implant crevicular fluid (PICF) during the wound healing process. MATERIALS AND METHODS: Nineteen patients (25 implants) were recruited into this study. As part of the control group, gingival crevicular fluids (GCF) from healthy teeth were collected before implant placement. PICF specimens from each implant were collected during weeks 2 to 12 after implant placement. All GCF and PICF specimens were centrifuged to collect the supernatant as cell-free DNA. Five primer pairs specific to the ß-globin gene for amplifying 110-base pair (bp), 325-bp, 408-bp, 536-bp, and 2-kilo-base pair (kb) amplicons were used to evaluate DNA fragment lengths with conventional polymerase chain reaction (PCR). The longest PCR amplicon of each specimen was recorded. RESULTS: The number of 536-bp amplicons (10 of 25 implant specimens) and 2-kb amplicons (8 of 25 implant specimens) in week 2 was higher than at the other visits. In the study, the mucositis group showed the highest number of 536-bp amplicons (22 of 34 implant specimens) and 2-kb amplicons (12 of 34 implant specimens), whereas the healthy implant group showed a low number of 536-bp amplicons (3 of 66 implant specimens), and the cell-free PICF specimens had no 2-kb amplicons. Furthermore, 325-bp and 110-bp amplicons were similar in number in the control teeth and healthy implants. CONCLUSION: There was a difference in the number of the longest amplicons of cell-free PICF specimens between the mucositis and healthy implant groups. This pilot study suggests that the PCR amplicon lengths of ß-globin gene fragments in cell-free PICF specimens might be used as a biomarker to monitor soft tissue inflammation around implants.

The effects of silane-SiO2 nanocomposite films on Candida albicans adhesion and the surface and physical properties of acrylic resin denture base material.

STATEMENT OF PROBLEM: Polysiloxane has been used as a coupling material in restorative dental materials for several decades. However, few studies are available on the application of polysiloxane in other dental prosthesis functions. PURPOSE: The purpose of this study was to investigate the effects of silane-SiO2 nanocomposite films on Candida albicans adhesion and the surface and physical properties of acrylic resin denture base materials. MATERIAL AND METHODS: Specimens were separated into 2 groups, uncoated and coated. They were coated with a film by using the dip-coating method. Specimens were incubated with Candida albicans 10(7) cells/mL for 1 hour, and the adherent cells were counted under an optical microscope. The following surface properties were measured: surface chemical composition with Fourier-transform infrared spectrometry, surface roughness with a surface profiler, surface energy with the sessile drop method, and surface hardness with a microhardness tester. The physical properties, including water sorption, water solubility, ultimate flexural strength, and flexural modulus, were evaluated according to International Organization for Standardization 20795-1 requirements. The adhesion of Candida albicans and the surface properties of the specimens were investigated after cleaning with effervescent tablets and brushing. An MTT assay was used to evaluate the coated specimens. The results were statistically analyzed with the Mann-Whitney U test (α=.05). RESULTS: A significant reduction in Candida albicans adhesion (P=.002) was observed before cleaning. In addition, the surface energy was comparable (P=.100), the surface hardness increased significantly (P=.008), and the surface roughness remained unchanged (P=.310). After cleaning with effervescent tablets, a significant decrease in Candida albicans adhesion (P=.002) and in surface roughness (P=.008) was observed; however, similar surface energies were measured (P=.100). After cleaning with a toothbrush, the adhesion of Candida albicans was significantly higher on the coated specimen than on the uncoated specimen (P=.004). The surface roughness values were significantly different (P=.008), and the surface energies could not be determined. The coated specimen had a silicon-oxygen-silicon peak instead of an ester bond in the polymethyl methacrylate structure. The coating film reduced the water sorption (P=.008) and water solubility (P=.032), and increased the ultimate flexural strength (P=.008) and flexural modulus (P=.032) of the specimen. The coated specimen also had satisfactory toxicity results. CONCLUSIONS: Reduced Candida albicans adhesion was observed on the coated specimens. The polymeric film did not change the surface roughness of the acrylic resin specimen; however, it did slightly reduce the surface energy. The physical properties of the acrylic resin did not decrease after it was coated with the film.

Association of untreated metabolic syndrome with moderate to severe periodontitis in Thai population.

BACKGROUND: Metabolic syndrome (MetS) correlates with systemic inflammation. A relation of MetS to periodontitis has been reported. This study aims to evaluate whether periodontitis is associated with untreated MetS, plasma adiponectin, and leptin among Thai people. METHODS: One hundred twenty-five participants (aged 35 to 76 years) were recruited. Demographic and biologic data, bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) of all teeth were examined. Plasma adiponectin and leptin levels were measured. RESULTS: Forty-four participants (35.2%) were healthy, and 81 (64.8%) had MetS. All periodontal conditions (BOP, PD, and CAL) were significantly worse in patients with MetS than healthy participants. After adjustment for confounders, MetS was strongly associated with severe periodontitis (odds ratio [OR] = 3.60, 95% confidence interval [CI]: 1.34 to 9.65). MetS with four to five components had a higher association with periodontitis than did MetS with three components (OR = 5.49, 95% CI: 1.75 to 17.19), whereas each separate component had no association with periodontitis, except for high diastolic blood pressure. Periodontitis was also associated with age (OR = 1.08, 95% CI: 1.01 to 1.14) and education (OR = 3.76, 95% CI: 1.05 to 13.40). The risk of MetS was predicted by body mass index and plasma adiponectin (OR = 1.90, 95% CI: 1.24 to 2.92 and OR = 0.93, 95% CI: 0.88 to 0.98, respectively). CONCLUSIONS: There may be a relationship between untreated MetS and periodontitis in Thai people. Periodontal diagnosis should be regularly conducted in patients with MetS.

Comparison of salivary and plasma adiponectin and leptin in patients with metabolic syndrome.

BACKGROUND: The relationship of saliva with plasma protein levels makes saliva an attractive diagnostic tool. Plasma levels of adiponectin and leptin in healthy individuals or diabetes mellitus patients have been previously reported. Nevertheless, salivary levels of these adipocytokines in patients with metabolic syndrome (MS) have never been investigated. This study was aimed to determine adiponectin and leptin levels in saliva and plasma from patients with metabolic syndrome, and evaluate any correlation of these levels with MS. METHODS: Forty-six healthy and 82 MS patients were enrolled. Demographic data and blood biochemistries were recorded. Saliva and plasma adiponectin and leptin levels were analyzed by enzyme-linked immunosorbent assay (ELISA). RESULTS: Adiponectin and leptin were higher in plasma than in saliva (p < .001). Plasma adiponectin was decreased and plasma leptin increased in patients with MS (p < .001). Salivary adiponectin and salivary leptin were not different between healthy subjects and MS patients (p = .619 and p = .523). Correlation between salivary and plasma adiponectin showed significant association (r = .211, p = .018) while salivary and plasma leptin had no correlation (r = -.161, p = .069). Significant correlation was observed between the salivary adiponectin/salivary leptin ratio and plasma adiponectin (r = .371, p < .001), but not with any component of MS. Increased triglyceride and waist circumference were associated with risk of having a low level of plasma adiponectin (OR = 1.009; 95% CI 1.002-1.015 and OR = 1.125; 95% CI 1.029-1.230). For leptin, body mass index and high-density lipoprotein cholesterol (HDL-C) were associated with a high level of plasma leptin (OR = 1.621; 95% CI 1.212-2.168 and OR = .966; 95% CI .938-.996). The OR for MS as predicted by plasma adiponectin was .928 (95% CI .881-.977). CONCLUSIONS: This study showed that salivary adiponectin and leptin do not correlate with MS. Although correlation between salivary and plasma adiponectin was observed, no association with MS was observed. Only plasma adiponectin may be useful for the prediction of MS.

In vitro effects of Salvia officinalis L. essential oil on Candida albicans.

OBJECTIVE: To determine the anticandidal activities of Salvia officinalis L. (S. officinalis) essential oil against Candida albicans (C. albicans) and the inhibitory effects on the adhesion of C. albicans to polymethyl methacrylate (PMMA) resin surface. METHODS: Disc diffusion method was first used to test the anticandidal activities of the S. officinalis L. essential oil against the reference strain (ATCC 90028) and 2 clinical strains of C. albicans. Then the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined by modified membrane method. The adhesion of C. albicans to PMMA resin surface was assessed after immersion with S. officinalis L. essential oil at various concentrations of 1×MIC, 0.5×MIC and 0.25×MIC at room temperature for 30 min. One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey's test was used for multiple comparisons. RESULTS: S. officinalis L. essential oil exhibited anticandidal activity against all strains of C. albicans with inhibition zone ranging from 40.5 mm to 19.5 mm. The MIC and MLC of the oil were determined as 2.780 g/L against all test strains. According to the effects on C. albicans adhesion to PMMA resin surface, it was found that immersion in the essential oil at concentrations of 1×MIC (2.780 g/L), 0.5×MIC (1.390 g/L) and 0.25×MIC (0.695 g/L) for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner (P<0.05). CONCLUSIONS: S. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface. With further testing and development, S. officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis.

Antimicrobial effects of silver zeolite, silver zirconium phosphate silicate and silver zirconium phosphate against oral microorganisms.

OBJECTIVE: To evaluate the antimicrobial activities of silver inorganic materials, including silver zeolite (AgZ), silver zirconium phosphate silicate (AgZrPSi) and silver zirconium phosphate (AgZrP), against oral microorganisms. In line with this objective, the morphology and structure of each type of silver based powders were also investigated. METHODS: The antimicrobial activities of AgZ, AgZrPSi and AgZrP were tested against Streptococcus mutans, Lactobacillus casei, Candida albicans and Staphylococcus aureus using disk diffusion assay as a screening test. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the modified membrane method. Scanning electron microscope and X-ray diffraction were used to investigate the morphology and structure of these silver materials. RESULTS: All forms of silver inorganic materials could inhibit the growth of all test microorganisms. The MIC of AgZ, AgZrPSi and AgZrP was 10.0 g/L whereas MLC ranged between 10.0-60.0 g/L. In terms of morphology and structure, AgZrPSi and AgZrP had smaller sized particles (1.5-3.0 µm) and more uniformly shaped than AgZ. CONCLUSIONS: Silver inorganic materials in the form of AgZ, AgZrPSi and AgZrP had antimicrobial effects against all test oral microorganisms and those activities may be influenced by the crystal structure of carriers. These results suggest that these silver materials may be useful metals applied to oral hygiene products to provide antimicrobial activity against oral infection.

In vitro antimicrobial effects of grape seed extract on peri-implantitis microflora in craniofacial implants.

OBJECTIVE: To determine the antimicrobial effects of grape seed on peri-implantitis microflora. METHODS: The grape seed extract was tested against peri-implantitis microflora most commonly found in craniofacial implants including reference strains of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Candida albicans (C. albicans) and clinical strains of S. aureus, Klebsiella pneumonia (K. pneumonia) and Candida parapsilosis (C. parapsilosis) by disk diffusion test. Minimum inhibitory concentrations (MIC) and minimum cidal concentrations (MCC) were determined using modified agar dilution millpore method. The extract was further combined with polyethylene glycol and propylene glycol, and was tested for antimicrobial effects. RESULTS: Grape seed extract showed positive inhibitory effects with S. aureus at MIC of 0.625 mg/mL and MCC of 1.25 mg/mL respectively. However the extracts showed minimal or no reactivity against strains of E. coli, K. pneumonia, C. parapsilosis and C. albicans. The use of grape seed extract in combination with polyethylene glycol and propylene glycol also showed dose dependent inhibitory effect on S. aureus. CONCLUSIONS: The results of the study showed that grape seed has potential antimicrobial effects which can be further studied and developed to be used in the treatment of infected skin-abutment interface of craniofacial implants.

In vitro antimicrobial effects of grape seed extract on peri-implantitis microflora in craniofacial implants

To determine the antimicrobial effects of grape seed on peri-implantitis microflora.Methods:The grape seed extract was tested against peri-implantitis microflora most commonly found in craniofacial implants including reference strains of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Candida albicans (C. albicans) and clinical strains of S. aureus, Klebsiella pneumonia (K. pneumonia) and Candida parapsilosis (C. parapsilosis) by disk diffusion test. Minimum inhibitory concentrations (MIC) and minimum cidal concentrations (MCC) were determined using modified agar dilution millpore method. The extract was further combined with polyethylene glycol and propylene glycol, and was tested for antimicrobial effects. Results: Grape seed extract showed positive inhibitory effects with S. aureus at MIC of 0.625 mg/mL and MCC of 1.25 mg/mL respectively. However the extracts showed minimal or no reactivity against strains of E. coli, K. pneumonia, C. parapsilosis and C. albicans. The use of grape seed extract in combination with polyethylene glycol and propylene glycol also showed dose dependent inhibitory effect on S.aureus. Conclusions: The results of the study showed that grape seed has potential antimicrobial effects which can be further studied and developed to be used in the treatment of infected skin-abutment interface of craniofacial implants.

Effect of Phyllanthus emblica Linn. on candida adhesion to oral epithelium and denture acrylic.

OBJECTIVE: To investigate the effect of Phyllanthus emblica (P. emblica) Linn. ethanolic extract on the adhesion of Candida albicans (C. albicans) to human buccal epithelial cells (BECs) and denture acrylic surfaces. METHODS: Human BECs and transparent acrylic strips were pretreated with ethanolic extract solution of P. emblica fruits at concentration ranged from 18.7 to 300 mg/mL. After washing BECs and the strips were inoculated with three strains of C. albicans (ATCC 10281 and two clinical isolates) (10(7) cells/mL). Normal saline solution (NSS) and 0.2% chlorhexidine gluconate were used as negative and positive controls, respectively. BECs were harvested on 12 µm-polycarbonate filters (Millipore, USA). The membrane filters and the strips were stained with Gram stain. Adherent yeast cells on 100 randomly selected epithelial cells and 20 randomly selected fields on each strip were counted under microscope. The statistical significance was calculated by Kruskal-Wallis and Tukey tests at a significant level of P< 0.05. RESULTS: Significant lower numbers of all strains of yeasts adhering to BECs and acrylic strips were observed after exposure to 75-300 mg/mL of plant extract compared with NSS. CONCLUSIONS: The present study demonstrates that P. emblica ethanolic extract interferes with the adhesion of C. albicans to BECs and denture acrylic surfaces in vitro.

Effect of an essential oil-containing mouth rinse on VSC-producing bacteria on the tongue.

The objective of the present study was to investigate the inhibitory effect of a commercially available essential oil-containing mouth rinse 12 hours after a single rinse and two weeks of twice daily rinsing, on volatile sulphur compounds (VSC) producing bacteria on the tongue. The study was a randomized, double-blind, controlled crossover design. Thirty-six healthy subjects, aged 20-48 years, volunteered to participate in the study. Subjects were randomly assigned to rinse twice daily with either an essential oil-containing mouth rinse (Cool Mint Listerine Antiseptic) or a negative control rinse. Bacteria samples were taken from the dorsum of the tongue at baseline, after the first rinse and two weeks later. They were plated on OOPS medium to enumerate the VSC-producing bacteria. Intergroup comparisons of log10 transformed colony-forming units of the samples were made using analysis of covariance. Each comparison was performed at a 5% significance level. The mean VSC-producing bacteria in subjects using the essential oil mouth rinse were significantly lower than those using the control rinse twice daily. In healthy subjects, rinsing with an essential oil-containing mouth rinse can have a significant effect on VSC-producing bacteria on the tongue and may be useful for controlling intrinsic oral malodor over prolonged periods.

Efficacy of xylitol and fluoride mouthrinses on salivary Mutans streptococci.

OBJECTIVE: To evaluate the level of salivary Mutans streptococci (MS) after rinsing with xylitol, fluoride, and a combination of xylitol and fluoride solutions, compared with distilled water. METHODS: Eighty healthy 8-9 years old subjects with high level of MS (> 10(5) CFU/mL) were equally divided into 4 groups. Subjects rinsed their mouths for 1 min with 10 mL of 0.05% (w/v) sodium fluoride (NaF), 12.5% (w/v) xylitol or 0.05% (w/v) NaF + 12.5% (w/v) xylitol 3 times daily over 10 weeks. Distilled water rinsed group served as a control. Paraffin-stimulated whole saliva samples were collected at baseline, 5 weeks, and 10 weeks after rinsing to determine the level of salivary MS by culturing on Mitis Salivarius Bacitracin agar. The statistical significance was calculated by Kruskal Wallis, Mann Whitney U, and Wilcoxon signed-rank tests at a significant level of P< 0.05. RESULTS: Significant reductions in MS count were observed in subjects using 0.05% NaF + 12.5% xylitol over other groups within 5 weeks and after 10 weeks and 12.5% xylitol alone after 10 weeks compared with baseline. CONCLUSIONS: The present study provides evidence for the inhibitory effect of xylitol, used in combination with fluoride, delivered in the form of mouthrinse, on salivary MS in the group of schoolchildren.

Fermentation of various sugars and sugar substitutes by oral microorganisms

Objective: To examine acid production of caries-associated strains of oral microorganisms and salivary microorganisms from sugar and sugar substitutes. Methods:Standard and clinical strains of Streptococcus mutans (S. mutans), Lactobacillus casei (L. casei) and Candida albicans were incubated in peptone-yeast-extract media containing 1% test sugar (sucrose, glucose, fructose) or sugar substitutes (xylitol, sorbitol, trehalulose and palatinose) at 37 ℃in 5% CO2 for 24-48 h. The pH of each culture was measured and microbial growth was determined as optical density at 660 nm. Paraffin-stimulated saliva collected from high caries-risk persons were added to media containing 10%test sugar or sugar substitutes. The pH of medium was measured at each time interval from 0-90 minutes. Results:All types of sugar and trehalulose could be fermented by all test microorganisms in pH lower than 5.5 except sucrose by standard strain of L. casei. All sugar and sugar substitutes supported growth of all organisms except xylitol for S. mutans. In the fermentation assay by salivary microorganisms, all sugar could be utilized and produced pH< 5.5 within 10 minutes of incubation and the pH drop was prolonged to until 90 minutes. Conversely, xylitol and palatinose were not fermented by microorganisms in saliva. Conclusions:All test microorganisms could ferment sucrose, glucose, fructose and trehalulose to pH lower than 5.5. Sugar alcohols and palatinose were not utilized well by organisms and may be used as sugar substitutes to reduce dental caries incidence. However, further studies particularly clinical investigations are required to evaluate the cariogenicity of these sugar substitutes.

In vitro antimicrobial activity of Ocimum americanum L. essential oil against oral microorganisms.

The aim of the present study was to evaluate the efficacy of the essential oil of Ocimum americanum L. on in vitro activity against Streptococcus mutans, Lactobacillus casei and Candida albicans. An agar disk diffusion method was employed for screening antimicrobial activity. Minimum inhibitory concentration (MIC) and minimum cidal concentration (MCC) values of the oil against planktonic cells were determined using the Millipore membrane method. The antimicrobial potential of the essential oil was also investigated with a biofilm model. The results indicate that essential oil has antimicrobial activity against all tested microorganisms. The MIC values of the oil against the three organisms was 0.04% v/v whereas the MCC values for S. mutans, L. casei and C. albicans were 0.08%, 0.3% and 0.08% v/v, respectively. S. mutans and C. albicans were more sensitive to the essential oil than L. casei. With the biofilm assay, a 5-minute exposure to 3% v/v essential oil eliminated 3 logo10 of the tested microorganisms. At a lower concentration (0.3% v/v), a 2 log10 reduction in S. mutans and C. albicans was observed while the lactobacilli were more resistant. This finding indicates the possibility of using the essential oil of O. americanum L. in oral health care products for reducing these pathogenic microorganisms in the oral cavity.