Compendium of continuing education in dentistry (Jamesburg, N.J.: 1995)
This investigation examined the in vitro and ex vivo antimicrobial effects of a new dentifrice, C... more This investigation examined the in vitro and ex vivo antimicrobial effects of a new dentifrice, Colgate Total Advanced Fresh, formulated with triclosan/copolymer/sodium fluoride, on oral bacteria, including those odorigenic bacteria implicated in bad breath. The effects of Colgate Total Advanced Fresh were compared to commercially available fluoride dentifrices that served as controls. Three experimental approaches were undertaken for these studies. In the first approach, the dentifrice formulations were tested in vitro against 13 species of oral bacteria implicated in bad breath. The second approach examined the antimicrobial activity derived from dentifrice that was adsorbed to and released from hydroxyapatite disks. In this approach, dentifrice-treated hydroxyapatite disks were immersed in a suspension of bacteria, and reduction in bacterial viability from the release of bioactive agents from hydroxyapatite was determined. The third approach examined the effect of treating bacteria immediately after their removal from the oral cavity of 11 adult human volunteers. This ex vivo study examined the viability of cultivable oral bacteria after dentifrice treatment for 2 minutes. Antimicrobial effects were determined by plating Colgate Total Advanced Fresh and control-dentifrice-treated samples on enriched media (for all cultivable oral bacteria) and indicator media (for hydrogen-sulfide-producing organisms), respectively. Results indicated that the antimicrobial effects of Colgate Total Advanced Fresh were significantly greater than either of the other dentifrices for all 13 oral odorigenic bacterial strains tested in vitro (P < or = 0.05). In the second approach, Colgate Total Advanced Fresh-treated hydroxyapatite disks were significantly more active in reducing bacterial growth than the other dentifrices tested (P < or = 0.05). Finally, ex vivo treatment of oral bacteria with Colgate Total Advanced Fresh demonstrated a 90.9% reduction of all oral cultivable bacteria and a 91.5% reduction of oral bacteria producing hydrogen sulfide compared with the control dentifrice. In conclusion, these results, taken together with the significant reductions in clinical malodor scores by Colgate Total Advanced Fresh demonstrated in organoleptic studies, strongly suggest that this dentifrice kills the bacteria that are implicated in the cause of bad breath.
This randomized double-blind clinical study evaluated the antimicrobial efficacy of two mouthwash... more This randomized double-blind clinical study evaluated the antimicrobial efficacy of two mouthwashes containing (1) 0.075% cetylpyridinium chloride (CPC) + 0.05% sodium fluoride (NaF) in an alcohol-free base and (2) 0.075% CPC + 0.05% NaF in a 6% alcohol base, versus a negative control mouthwash containing 0.05% NaF in an alcohol-free base on numbers of bacteria in supragingival plaque 12 hours after a single use and 12 hours after 14 days' use. Enrolled subjects completed a one-week washout phase prior to providing baseline samples of supragingival plaque that were analyzed for numbers of anaerobic microorganisms. Subjects were randomized to a treatment group and instructed to rinse with 20 mL of the assigned mouthwash for 30 seconds. Post-treatment microbiological analyses were conducted on plaque samples collected 12 hours after the first use of each assigned mouthwash and after completing 14 days of twice-daily use of each assigned mouthwash. Oral examinations were completed ...
This clinical study evaluated relief from dentin hypersensitivity among subjects who brushed thei... more This clinical study evaluated relief from dentin hypersensitivity among subjects who brushed their teeth with a new dentifrice containing 8.0% arginine, calcium carbonate, and 1000 ppm fluoride as sodium monofluorophosphate (MFP) to subjects who brushed with a commercially available dentifrice containing 1000 ppm MFP over an eight-week period. Adult subjects from the New Delhi, India area, with two teeth that exhibited dentin hypersensitivity, both to tactile stimulation using the Yeaple Probe and to stimulation using an air blast delivered by a standard dental unit syringe, were screened for study enrollment. Qualifying subjects were randomly assigned one of the study dentifrices and instructed to brush their teeth for one minute, twice daily (morning and evening) with the provided dentifrice. Follow-up examinations for dentin hypersensitivity were conducted after two, four, and eight weeks of product use. Subjects provided with the new dentifrice containing 8.0% arginine, calcium ...
Objectives: To quantify indole in unstimulated saliva and to compare the effect of two commercial... more Objectives: To quantify indole in unstimulated saliva and to compare the effect of two commercial mouthrinses on indole production. Methods: Following one-week of brushing with a fluoride-based toothpaste, each of ten healthy subjects provided 10 mL of unstimulated morning saliva prior to brushing, eating, and drinking. Saliva (2 mL) was transferred to a centrifuge tube and incubated for 24 h at 37 oC. Each sample was prepared in triplicate. The samples were then extracted with hexanes and analyzed for indole by GC-MS. Two commercially-available mouthrinses were evaluated for their effect on indole concentration, one containing AmF/SnF2 and zinc lactate and the other containing CPC and alcohol (15%). Water was used as a control. Following one week of brushing with a fluoride-based toothpaste, stimulated morning saliva was collected and pooled together from five healthy subjects. The saliva was provided prior to brushing, eating, and drinking. Saliva (2 mL) and tryptophan (0.3 mL, 1....
Objective: Triclosan (TCN) is a broad-spectrum antimicrobial agent which is effective against ora... more Objective: Triclosan (TCN) is a broad-spectrum antimicrobial agent which is effective against oral biofilm bacteria. Numerous clinical studies have demonstrated the efficacy of triclosan-containing dentifrices on oral health including reduced supragingival plaque, gingivitis and oral malodor. This study evaluated long-term bacterial susceptibility to TCN on human supragingival plaque samples collected from adults over a period of 20 years. Materials and Methods: There were 13 separate evaluations over 20 years, with data from 155 assessments presented in this report. Supragingival dental plaque was obtained from adults who had not received dental treatment or antimicrobial therapy in the previous 30 days. Supragingival plaque was collected from the entire dentition at each evaluation and aliquots of the subject's pooled plaque suspension were distributed onto agar media containing 0, 7.5 or 25 µg/ml TCN. Following incubation at 37oC for 5-7 days, the number of colony forming uni...
Objectives: This investigation evaluated the effects of Colgate Total (CT), Crest Pro-Health (CPH... more Objectives: This investigation evaluated the effects of Colgate Total (CT), Crest Pro-Health (CPH); sodium lauryl sulphate (SLS), triclosan (TCS), stannous fluoride (SF), zinc lactate (ZL) and ZLSF in combination on the microbial ecology of oral microcosms maintained in modified drip flow biofilm reactors (MDFRs) and hydroxyapatite disc bioreactors (HDBs). Methods: Fresh saliva was used to inoculate the MDFRs and HDBs. Antimicrobial agents were delivered to the MDFRs 4 times daily for 6 days and to the HDB once. Viable counts, gravimetric analysis and denaturing gradient gel electrophoresis (DGGE) were used to determine the antimicrobial effects. Results: Following multiple treatment periods, TCS was significantly more effective than ZLSF at reducing biomass (>95% at 6d) and ZLSF was significantly more effective than either ZL or SF at reducing the amounts of all functional bacterial groups. TCS significantly (P<0.05) targeted all groups monitored whilst ZLSF also caused signi...
Objective: Peri-implantitis caused by oral microorganisms can result in failure of dental implant... more Objective: Peri-implantitis caused by oral microorganisms can result in failure of dental implant therapy. This in vitro study evaluated an adenosine triphosphate (ATP) luminescence assay in conjunction with anaerobic culture and electron microscopy to compare the efficacy of mouthwashes in inhibiting oral biofilms on titanium surfaces. Methods: Biofilms were formed on titanium disks (10 mm x 1 mm) by incubation for 48 h at 37oC in brain heart infusion broth with human saliva. Biofilm laden disks were treated with; 1) 0.075% cetylpyridinium chloride oral rinse (CPC); 2) 0.075% CPC oral rinse with 225 ppm sodium fluoride (CPC-F); 3) 0.12% chlorhexidine gluconate oral rinse (CHX); or a 4) placebo rinse (P). Scanning electron microscopy (SEM) evaluated biofilm covered surface area. Bacterial viability on disks was assessed by anaerobic culture and by measuring ATP. Untreated, biofilm laden disks served as positive controls while untreated discs served as negative controls. Results: Com...
Compounds of natural origin are increasingly used as adjuncts to oral hygiene. We have adopted fo... more Compounds of natural origin are increasingly used as adjuncts to oral hygiene. We have adopted four distinct approaches to assess the antibacterial activity of dentifrices containing natural active ingredients against oral bacteria in several test systems. Corsodyl Daily (CD), Kingfisher Mint (KM), and Parodontax fluoride (PF) were compared to a dentifrice containing fluoride (Colgate Cavity Protection [CCP]) and one containing triclosan (Colgate Total [CT]). The growth inhibitory and bactericidal potency of the formulations were determined for 10 isolated oral bacteria. Effects of single exposures of simulated supragingival plaques were then determined by epifluorescence and confocal microscopy, while the effects of repeated exposures were quantified by viable counting. Additionally, dense plaques, maintained in continuous culture, were repeatedly dosed, and the outcome was assessed by viable counting and eubacterial DNA profiling. The test dentifrices exhibited variable specificit...
Previous studies suggest that Solobacterium moorei is associated with oral halitosis. In the pres... more Previous studies suggest that Solobacterium moorei is associated with oral halitosis. In the present study, we examined the prevalence of S. moorei on the dorsal surface of the tongue in 57 adults (21 with and 36 without halitosis) by bacterial culture and direct amplification of nucleic acids. We also examined the S. moorei type strain and four clinical isolates for 16S ribosomal nucleic acid sequence, H(2)S and enzyme production, and antibiotic susceptibility. S. moorei was found on the dorsal surface of the tongue in 100% of the subjects with halitosis and 14% of subjects without halitosis. Infection with S. moorei was correlated with organoleptic measures of halitosis and with volatile sulfur compound levels. Nucleic acid probe detection of S. moorei as a test for halitosis exhibited 100% sensitivity and 86% specificity. The S. moorei type strain and all four clinical isolates showed >98% 16S rDNA sequence similarity, produced H(2)S, demonstrated acid phosphatase, beta-galact...
To assess dental plaque on different regions of the dentition prior to and immediately after toot... more To assess dental plaque on different regions of the dentition prior to and immediately after toothbrushing. Subjects refrained from oral hygiene for 22-26 hours prior to baseline whole mouth plaque assessments by the Turesky modification of the Quigley-Hein Index (TMQH). All subjects brushed with a marketed soft-bristled toothbrush and a fluoride dentifrice for 1 minute prior to post-brushing plaque assessments similar to baseline. One calibrated clinical examiner conducted all measurements. 30 subjects (mean age 23 years) completed the study. Irrespective of arch, posterior teeth harbored higher frequencies for scores of 3-5 than corresponding anterior teeth prior to brushing. In comparison to the pre-brushing examination, scores of 0-1 were more common in the post-brushing evaluation, however, greater frequencies of higher plaque were observed on posterior than on anterior regions. Irrespective of gender, subject or arch, anterior teeth harbored lower mean amounts of plaque than p...
To examine the effects of routine use of two dentifrices on tooth stain. Single centre, parallel ... more To examine the effects of routine use of two dentifrices on tooth stain. Single centre, parallel design, double blind randomised clinical study with two treatment groups. Department of Dental Public Health, SDM College of Dental Sciences and Hospital, Dharwad, Karnataka, India. 125 of the 140 study subjects aged 18-70 years completed the 8-week study period. Subjects were randomly assigned to brush twice daily with fluoride toothpaste (control) or a dentifrice formulated with silicas (test) and recalled for tooth stain examinations after 4 and 8 weeks of dentifrice use. Modified Lobene tooth stain index. Whereas statistical analyses indicate no significant differences between the treatment groups for baseline scores of tooth stain intensity, stain area and tooth stain composite scores (p > 0.53), examinations demonstrate significant reductions in stain area, intensity and stain composite scores amongst subjects assigned the test dentifrice at both recall visits versus the control...
Objectives: This investigation assessed regional differences within the human dentition for denta... more Objectives: This investigation assessed regional differences within the human dentition for dental plaque in conjunction with microbiological analyses of dental plaque for anaerobic microorganisms. Methods: Forty-one adults (mean age 28 years) were enrolled prior to clinical evaluations for whole mouth dental plaque (PI) by the Turesky modification of the Quigley-Hein. Dental plaque was collected from anterior (teeth numbers 6-11 and 22 to 27) and posterior surfaces (teeth numbers 2-5, 12-15, 18-21 and 28-31) to enumerate viable bacteria on enriched media following anaerobic incubation at 37C for 7-days. Subjects underwent a whole mouth dental prophylaxis and utilized a fluoride toothpaste for oral hygiene. Evaluations during the day 15 and 30 recall visits included clinical examinations followed by dental plaque collection for microbiological analyses identical to baseline. Results: At baseline, chi-square analyses indicate significantly lower frequencies of plaque scores amongst a...
 The human oral cavity contains several microenvironments or ecologic niches. While mechanical pl... more  The human oral cavity contains several microenvironments or ecologic niches. While mechanical plaque control is well known to reduce the number of supragingival dental plaque bacteria, there is little data on antimicrobial effects in other oral ecologic niches. The present study examined the effects of mechanical plaque control using a microbead dentifrice on bacteria colonizing oral ecologic niches. Twenty-two adults (aged 18-70years) including nine generalized moderate chronic periodontitis subjects and 13 periodontally healthy subjects having average gingival indices ≥1 and plaque indices ≥1.5 completed a 1week washout phase and refrained from oral hygiene the morning of baseline sample collection. Microbial samples from supragingival dental plaque, buccal mucosa, dorsal surface of the tongue and whole mixed saliva were obtained. Subjects brushed with a microbead dentifrice and, after 10min, sampling was repeated. The number of anaerobic bacteria was determined by culture on non-selective media and transformed to log(10) for statistical analyses.   Mechanical plaque control using the microbead dentifrice resulted in statistically significant reductions in bacterial numbers in each ecologic niche (P&lt;0.001). The greatest reduction in the number of viable bacteria occurred in samples taken from the buccal mucosa (97.22%) followed by a 95.22% reduction in supragingival plaque bacteria, a 94.51% reduction in the number of bacteria on the dorsal surface of the tongue and a 91.57% reduction in the number of bacteria in whole mixed saliva. Mechanical plaque control using a microbead dentifrice reduces microbial load in microenvironments throughout the human oral cavity.
This investigation evaluated extrinsic stain removal efficacy after brushing for one and two week... more This investigation evaluated extrinsic stain removal efficacy after brushing for one and two weeks with a commercially available fluoride dentifrice relative to Colgate Total Advanced Clean, a new dentifrice formulated with dual-phase silica. At the baseline visit, one-hundred and forty-four adult subjects were stratified by Lobene Stain Index scores and randomized to two treatment groups using either Total Advanced Clean dentifrice (0.3% triclosan, 2% copolymer, dual phase silica) or a commercially available fluoride dentifrice, and instructed to brush twice daily. Tooth stain evaluations were conducted on stain area, stain intensity, and a composite score of both, after one and two weeks of dentifrice use. Baseline scores demonstrated no significant differences between the two treatment groups for all evaluated stain parameters (p > 0.05). At both the one- and two-week post-use evaluations, subjects brushing with Total Advanced Clean demonstrated significant reductions for all ...
This investigation assessed regional differences in dental plaque and gingivitis within the human... more This investigation assessed regional differences in dental plaque and gingivitis within the human dentition in conjunction with microbiological analyses of dental plaque. Forty-one adults (23 males and 18 females; age range 19-44 years) were enrolled, and a calibrated dental examiner completed whole mouth examinations for dental plaque (PI) and gingivitis (GI) using the Turesky modification of the Quigley-Hein Index (TMQH) and the L6e-Silness (LS) Index, respectively. Dental plaque samples were collected from the anterior surfaces and posterior teeth to determine viable anaerobic bacteria. During this visit, subjects underwent a whole mouth dental prophylaxis and were provided a marketed fluoride dentifrice for twice-daily oral hygiene. Subjects were recalled on day 15 and day 30 for whole mouth assessments of PI and GI, followed by the collection of dental plaque from the anterior and posterior teeth for microbiological analyses during these visits. Low plaque and gingival scores w...
A collection of 39 isolates of Actinobacillus actinomycetemcomitans, obtained from laboratories l... more A collection of 39 isolates of Actinobacillus actinomycetemcomitans, obtained from laboratories located in 5 different geographical regions of the United States, was examined for the presence of plasmid DNA. Only 2 of the strains examined, designated VT736 and VT745, harbored detectable plasmids. Strain VT736 contained a 1.9 kb plasmid species (pVT736-1) and a larger ( &gt; 30 kb) species (pVT736-2). Both plasmids were detected in the covalently closed circular DNA fraction of dye buoyant density gradients. However, only the smaller plasmid was observed in agarose gels containing plasmid-enriched cell lysates prepared by a rapid screening procedure. Strain VT745 contained a single, 24 kb, plasmid (pVT745) that was observed consistently in plasmid-enriched lysates, as well as in the plasmid band of dye buoyant density gradients. A restriction endonuclease map of pVT736-1 was constructed. The plasmid contained one site each for the enzymes HincII, KpnI and XhoI, located 600 to 700 bp from each other on the pVT736-1 map. HincII-digested pVT736-1 DNA could not be cloned in Escherichia coli. However, intact pVT736-1 digested with KpnI or XhoI could be cloned in E. coli on pUC19 or pGEM7Zf(-), respectively. KpnI-digested pVT736-1 was cloned in both orientations on pUC19, but XhoI-digested pVT736-1 was clonable in only one orientation on pGEM7Zf(-). Each of the 3 types of chimeric plasmid constructs provided a potential A. actinomycetemcomitans/E. coli shuttle plasmid for the development of a genetic transfer system in A. actinomycetemcomitans.
A simple in vivo approach to examine early dental plaque formation in the human mouth and to dete... more A simple in vivo approach to examine early dental plaque formation in the human mouth and to determine the effects of common dietary and oral hygiene procedures on biofilm formation is reported. A custom designed device that fits securely behind the teeth of the mandibular arch provides a surface for microbial colonization. This device is prepared with denture acrylic and can be repeatedly used by the subject, exposing a large and constant surface area for microbial accumulation. Large numbers of oral bacteria colonized the device by 2 h; these increased significantly by 4 h (P &lt; 0.05). Bacterial colonization increased significantly after rinsing with a sucrose solution (P &lt; 0.05) but remained unaffected after rinsing with water, a commercially available fluoride mouthrinse without antimicrobial agents, or brushing with a fluoride dentifrice (P &gt; 0.05). Rinsing with mouthrinses formulated with chlorhexidine, cetylpyridinium chloride or triclosan/copolymer significantly inhibited colonization (P &lt; 0.05). A dose-dependent inhibition was noted with chlorhexidine rinses (P &lt; 0.05). Brushing with a triclosan/copolymer dentifrice significantly inhibited microbial colonization compared with a control (P &lt; 0.05). This simple approach was useful for examining the effects of common dietary and oral hygiene procedures. Significant biofilm inhibitory effects were noted with formulations that demonstrated efficacy in previous clinical studies.
Compendium of continuing education in dentistry (Jamesburg, N.J.: 1995)
This investigation examined the in vitro and ex vivo antimicrobial effects of a new dentifrice, C... more This investigation examined the in vitro and ex vivo antimicrobial effects of a new dentifrice, Colgate Total Advanced Fresh, formulated with triclosan/copolymer/sodium fluoride, on oral bacteria, including those odorigenic bacteria implicated in bad breath. The effects of Colgate Total Advanced Fresh were compared to commercially available fluoride dentifrices that served as controls. Three experimental approaches were undertaken for these studies. In the first approach, the dentifrice formulations were tested in vitro against 13 species of oral bacteria implicated in bad breath. The second approach examined the antimicrobial activity derived from dentifrice that was adsorbed to and released from hydroxyapatite disks. In this approach, dentifrice-treated hydroxyapatite disks were immersed in a suspension of bacteria, and reduction in bacterial viability from the release of bioactive agents from hydroxyapatite was determined. The third approach examined the effect of treating bacteria immediately after their removal from the oral cavity of 11 adult human volunteers. This ex vivo study examined the viability of cultivable oral bacteria after dentifrice treatment for 2 minutes. Antimicrobial effects were determined by plating Colgate Total Advanced Fresh and control-dentifrice-treated samples on enriched media (for all cultivable oral bacteria) and indicator media (for hydrogen-sulfide-producing organisms), respectively. Results indicated that the antimicrobial effects of Colgate Total Advanced Fresh were significantly greater than either of the other dentifrices for all 13 oral odorigenic bacterial strains tested in vitro (P &amp;amp;amp;amp;amp;amp;lt; or = 0.05). In the second approach, Colgate Total Advanced Fresh-treated hydroxyapatite disks were significantly more active in reducing bacterial growth than the other dentifrices tested (P &amp;amp;amp;amp;amp;amp;lt; or = 0.05). Finally, ex vivo treatment of oral bacteria with Colgate Total Advanced Fresh demonstrated a 90.9% reduction of all oral cultivable bacteria and a 91.5% reduction of oral bacteria producing hydrogen sulfide compared with the control dentifrice. In conclusion, these results, taken together with the significant reductions in clinical malodor scores by Colgate Total Advanced Fresh demonstrated in organoleptic studies, strongly suggest that this dentifrice kills the bacteria that are implicated in the cause of bad breath.
This randomized double-blind clinical study evaluated the antimicrobial efficacy of two mouthwash... more This randomized double-blind clinical study evaluated the antimicrobial efficacy of two mouthwashes containing (1) 0.075% cetylpyridinium chloride (CPC) + 0.05% sodium fluoride (NaF) in an alcohol-free base and (2) 0.075% CPC + 0.05% NaF in a 6% alcohol base, versus a negative control mouthwash containing 0.05% NaF in an alcohol-free base on numbers of bacteria in supragingival plaque 12 hours after a single use and 12 hours after 14 days' use. Enrolled subjects completed a one-week washout phase prior to providing baseline samples of supragingival plaque that were analyzed for numbers of anaerobic microorganisms. Subjects were randomized to a treatment group and instructed to rinse with 20 mL of the assigned mouthwash for 30 seconds. Post-treatment microbiological analyses were conducted on plaque samples collected 12 hours after the first use of each assigned mouthwash and after completing 14 days of twice-daily use of each assigned mouthwash. Oral examinations were completed ...
This clinical study evaluated relief from dentin hypersensitivity among subjects who brushed thei... more This clinical study evaluated relief from dentin hypersensitivity among subjects who brushed their teeth with a new dentifrice containing 8.0% arginine, calcium carbonate, and 1000 ppm fluoride as sodium monofluorophosphate (MFP) to subjects who brushed with a commercially available dentifrice containing 1000 ppm MFP over an eight-week period. Adult subjects from the New Delhi, India area, with two teeth that exhibited dentin hypersensitivity, both to tactile stimulation using the Yeaple Probe and to stimulation using an air blast delivered by a standard dental unit syringe, were screened for study enrollment. Qualifying subjects were randomly assigned one of the study dentifrices and instructed to brush their teeth for one minute, twice daily (morning and evening) with the provided dentifrice. Follow-up examinations for dentin hypersensitivity were conducted after two, four, and eight weeks of product use. Subjects provided with the new dentifrice containing 8.0% arginine, calcium ...
Objectives: To quantify indole in unstimulated saliva and to compare the effect of two commercial... more Objectives: To quantify indole in unstimulated saliva and to compare the effect of two commercial mouthrinses on indole production. Methods: Following one-week of brushing with a fluoride-based toothpaste, each of ten healthy subjects provided 10 mL of unstimulated morning saliva prior to brushing, eating, and drinking. Saliva (2 mL) was transferred to a centrifuge tube and incubated for 24 h at 37 oC. Each sample was prepared in triplicate. The samples were then extracted with hexanes and analyzed for indole by GC-MS. Two commercially-available mouthrinses were evaluated for their effect on indole concentration, one containing AmF/SnF2 and zinc lactate and the other containing CPC and alcohol (15%). Water was used as a control. Following one week of brushing with a fluoride-based toothpaste, stimulated morning saliva was collected and pooled together from five healthy subjects. The saliva was provided prior to brushing, eating, and drinking. Saliva (2 mL) and tryptophan (0.3 mL, 1....
Objective: Triclosan (TCN) is a broad-spectrum antimicrobial agent which is effective against ora... more Objective: Triclosan (TCN) is a broad-spectrum antimicrobial agent which is effective against oral biofilm bacteria. Numerous clinical studies have demonstrated the efficacy of triclosan-containing dentifrices on oral health including reduced supragingival plaque, gingivitis and oral malodor. This study evaluated long-term bacterial susceptibility to TCN on human supragingival plaque samples collected from adults over a period of 20 years. Materials and Methods: There were 13 separate evaluations over 20 years, with data from 155 assessments presented in this report. Supragingival dental plaque was obtained from adults who had not received dental treatment or antimicrobial therapy in the previous 30 days. Supragingival plaque was collected from the entire dentition at each evaluation and aliquots of the subject's pooled plaque suspension were distributed onto agar media containing 0, 7.5 or 25 µg/ml TCN. Following incubation at 37oC for 5-7 days, the number of colony forming uni...
Objectives: This investigation evaluated the effects of Colgate Total (CT), Crest Pro-Health (CPH... more Objectives: This investigation evaluated the effects of Colgate Total (CT), Crest Pro-Health (CPH); sodium lauryl sulphate (SLS), triclosan (TCS), stannous fluoride (SF), zinc lactate (ZL) and ZLSF in combination on the microbial ecology of oral microcosms maintained in modified drip flow biofilm reactors (MDFRs) and hydroxyapatite disc bioreactors (HDBs). Methods: Fresh saliva was used to inoculate the MDFRs and HDBs. Antimicrobial agents were delivered to the MDFRs 4 times daily for 6 days and to the HDB once. Viable counts, gravimetric analysis and denaturing gradient gel electrophoresis (DGGE) were used to determine the antimicrobial effects. Results: Following multiple treatment periods, TCS was significantly more effective than ZLSF at reducing biomass (>95% at 6d) and ZLSF was significantly more effective than either ZL or SF at reducing the amounts of all functional bacterial groups. TCS significantly (P<0.05) targeted all groups monitored whilst ZLSF also caused signi...
Objective: Peri-implantitis caused by oral microorganisms can result in failure of dental implant... more Objective: Peri-implantitis caused by oral microorganisms can result in failure of dental implant therapy. This in vitro study evaluated an adenosine triphosphate (ATP) luminescence assay in conjunction with anaerobic culture and electron microscopy to compare the efficacy of mouthwashes in inhibiting oral biofilms on titanium surfaces. Methods: Biofilms were formed on titanium disks (10 mm x 1 mm) by incubation for 48 h at 37oC in brain heart infusion broth with human saliva. Biofilm laden disks were treated with; 1) 0.075% cetylpyridinium chloride oral rinse (CPC); 2) 0.075% CPC oral rinse with 225 ppm sodium fluoride (CPC-F); 3) 0.12% chlorhexidine gluconate oral rinse (CHX); or a 4) placebo rinse (P). Scanning electron microscopy (SEM) evaluated biofilm covered surface area. Bacterial viability on disks was assessed by anaerobic culture and by measuring ATP. Untreated, biofilm laden disks served as positive controls while untreated discs served as negative controls. Results: Com...
Compounds of natural origin are increasingly used as adjuncts to oral hygiene. We have adopted fo... more Compounds of natural origin are increasingly used as adjuncts to oral hygiene. We have adopted four distinct approaches to assess the antibacterial activity of dentifrices containing natural active ingredients against oral bacteria in several test systems. Corsodyl Daily (CD), Kingfisher Mint (KM), and Parodontax fluoride (PF) were compared to a dentifrice containing fluoride (Colgate Cavity Protection [CCP]) and one containing triclosan (Colgate Total [CT]). The growth inhibitory and bactericidal potency of the formulations were determined for 10 isolated oral bacteria. Effects of single exposures of simulated supragingival plaques were then determined by epifluorescence and confocal microscopy, while the effects of repeated exposures were quantified by viable counting. Additionally, dense plaques, maintained in continuous culture, were repeatedly dosed, and the outcome was assessed by viable counting and eubacterial DNA profiling. The test dentifrices exhibited variable specificit...
Previous studies suggest that Solobacterium moorei is associated with oral halitosis. In the pres... more Previous studies suggest that Solobacterium moorei is associated with oral halitosis. In the present study, we examined the prevalence of S. moorei on the dorsal surface of the tongue in 57 adults (21 with and 36 without halitosis) by bacterial culture and direct amplification of nucleic acids. We also examined the S. moorei type strain and four clinical isolates for 16S ribosomal nucleic acid sequence, H(2)S and enzyme production, and antibiotic susceptibility. S. moorei was found on the dorsal surface of the tongue in 100% of the subjects with halitosis and 14% of subjects without halitosis. Infection with S. moorei was correlated with organoleptic measures of halitosis and with volatile sulfur compound levels. Nucleic acid probe detection of S. moorei as a test for halitosis exhibited 100% sensitivity and 86% specificity. The S. moorei type strain and all four clinical isolates showed >98% 16S rDNA sequence similarity, produced H(2)S, demonstrated acid phosphatase, beta-galact...
To assess dental plaque on different regions of the dentition prior to and immediately after toot... more To assess dental plaque on different regions of the dentition prior to and immediately after toothbrushing. Subjects refrained from oral hygiene for 22-26 hours prior to baseline whole mouth plaque assessments by the Turesky modification of the Quigley-Hein Index (TMQH). All subjects brushed with a marketed soft-bristled toothbrush and a fluoride dentifrice for 1 minute prior to post-brushing plaque assessments similar to baseline. One calibrated clinical examiner conducted all measurements. 30 subjects (mean age 23 years) completed the study. Irrespective of arch, posterior teeth harbored higher frequencies for scores of 3-5 than corresponding anterior teeth prior to brushing. In comparison to the pre-brushing examination, scores of 0-1 were more common in the post-brushing evaluation, however, greater frequencies of higher plaque were observed on posterior than on anterior regions. Irrespective of gender, subject or arch, anterior teeth harbored lower mean amounts of plaque than p...
To examine the effects of routine use of two dentifrices on tooth stain. Single centre, parallel ... more To examine the effects of routine use of two dentifrices on tooth stain. Single centre, parallel design, double blind randomised clinical study with two treatment groups. Department of Dental Public Health, SDM College of Dental Sciences and Hospital, Dharwad, Karnataka, India. 125 of the 140 study subjects aged 18-70 years completed the 8-week study period. Subjects were randomly assigned to brush twice daily with fluoride toothpaste (control) or a dentifrice formulated with silicas (test) and recalled for tooth stain examinations after 4 and 8 weeks of dentifrice use. Modified Lobene tooth stain index. Whereas statistical analyses indicate no significant differences between the treatment groups for baseline scores of tooth stain intensity, stain area and tooth stain composite scores (p > 0.53), examinations demonstrate significant reductions in stain area, intensity and stain composite scores amongst subjects assigned the test dentifrice at both recall visits versus the control...
Objectives: This investigation assessed regional differences within the human dentition for denta... more Objectives: This investigation assessed regional differences within the human dentition for dental plaque in conjunction with microbiological analyses of dental plaque for anaerobic microorganisms. Methods: Forty-one adults (mean age 28 years) were enrolled prior to clinical evaluations for whole mouth dental plaque (PI) by the Turesky modification of the Quigley-Hein. Dental plaque was collected from anterior (teeth numbers 6-11 and 22 to 27) and posterior surfaces (teeth numbers 2-5, 12-15, 18-21 and 28-31) to enumerate viable bacteria on enriched media following anaerobic incubation at 37C for 7-days. Subjects underwent a whole mouth dental prophylaxis and utilized a fluoride toothpaste for oral hygiene. Evaluations during the day 15 and 30 recall visits included clinical examinations followed by dental plaque collection for microbiological analyses identical to baseline. Results: At baseline, chi-square analyses indicate significantly lower frequencies of plaque scores amongst a...
 The human oral cavity contains several microenvironments or ecologic niches. While mechanical pl... more  The human oral cavity contains several microenvironments or ecologic niches. While mechanical plaque control is well known to reduce the number of supragingival dental plaque bacteria, there is little data on antimicrobial effects in other oral ecologic niches. The present study examined the effects of mechanical plaque control using a microbead dentifrice on bacteria colonizing oral ecologic niches. Twenty-two adults (aged 18-70years) including nine generalized moderate chronic periodontitis subjects and 13 periodontally healthy subjects having average gingival indices ≥1 and plaque indices ≥1.5 completed a 1week washout phase and refrained from oral hygiene the morning of baseline sample collection. Microbial samples from supragingival dental plaque, buccal mucosa, dorsal surface of the tongue and whole mixed saliva were obtained. Subjects brushed with a microbead dentifrice and, after 10min, sampling was repeated. The number of anaerobic bacteria was determined by culture on non-selective media and transformed to log(10) for statistical analyses.   Mechanical plaque control using the microbead dentifrice resulted in statistically significant reductions in bacterial numbers in each ecologic niche (P&lt;0.001). The greatest reduction in the number of viable bacteria occurred in samples taken from the buccal mucosa (97.22%) followed by a 95.22% reduction in supragingival plaque bacteria, a 94.51% reduction in the number of bacteria on the dorsal surface of the tongue and a 91.57% reduction in the number of bacteria in whole mixed saliva. Mechanical plaque control using a microbead dentifrice reduces microbial load in microenvironments throughout the human oral cavity.
This investigation evaluated extrinsic stain removal efficacy after brushing for one and two week... more This investigation evaluated extrinsic stain removal efficacy after brushing for one and two weeks with a commercially available fluoride dentifrice relative to Colgate Total Advanced Clean, a new dentifrice formulated with dual-phase silica. At the baseline visit, one-hundred and forty-four adult subjects were stratified by Lobene Stain Index scores and randomized to two treatment groups using either Total Advanced Clean dentifrice (0.3% triclosan, 2% copolymer, dual phase silica) or a commercially available fluoride dentifrice, and instructed to brush twice daily. Tooth stain evaluations were conducted on stain area, stain intensity, and a composite score of both, after one and two weeks of dentifrice use. Baseline scores demonstrated no significant differences between the two treatment groups for all evaluated stain parameters (p > 0.05). At both the one- and two-week post-use evaluations, subjects brushing with Total Advanced Clean demonstrated significant reductions for all ...
This investigation assessed regional differences in dental plaque and gingivitis within the human... more This investigation assessed regional differences in dental plaque and gingivitis within the human dentition in conjunction with microbiological analyses of dental plaque. Forty-one adults (23 males and 18 females; age range 19-44 years) were enrolled, and a calibrated dental examiner completed whole mouth examinations for dental plaque (PI) and gingivitis (GI) using the Turesky modification of the Quigley-Hein Index (TMQH) and the L6e-Silness (LS) Index, respectively. Dental plaque samples were collected from the anterior surfaces and posterior teeth to determine viable anaerobic bacteria. During this visit, subjects underwent a whole mouth dental prophylaxis and were provided a marketed fluoride dentifrice for twice-daily oral hygiene. Subjects were recalled on day 15 and day 30 for whole mouth assessments of PI and GI, followed by the collection of dental plaque from the anterior and posterior teeth for microbiological analyses during these visits. Low plaque and gingival scores w...
A collection of 39 isolates of Actinobacillus actinomycetemcomitans, obtained from laboratories l... more A collection of 39 isolates of Actinobacillus actinomycetemcomitans, obtained from laboratories located in 5 different geographical regions of the United States, was examined for the presence of plasmid DNA. Only 2 of the strains examined, designated VT736 and VT745, harbored detectable plasmids. Strain VT736 contained a 1.9 kb plasmid species (pVT736-1) and a larger ( &gt; 30 kb) species (pVT736-2). Both plasmids were detected in the covalently closed circular DNA fraction of dye buoyant density gradients. However, only the smaller plasmid was observed in agarose gels containing plasmid-enriched cell lysates prepared by a rapid screening procedure. Strain VT745 contained a single, 24 kb, plasmid (pVT745) that was observed consistently in plasmid-enriched lysates, as well as in the plasmid band of dye buoyant density gradients. A restriction endonuclease map of pVT736-1 was constructed. The plasmid contained one site each for the enzymes HincII, KpnI and XhoI, located 600 to 700 bp from each other on the pVT736-1 map. HincII-digested pVT736-1 DNA could not be cloned in Escherichia coli. However, intact pVT736-1 digested with KpnI or XhoI could be cloned in E. coli on pUC19 or pGEM7Zf(-), respectively. KpnI-digested pVT736-1 was cloned in both orientations on pUC19, but XhoI-digested pVT736-1 was clonable in only one orientation on pGEM7Zf(-). Each of the 3 types of chimeric plasmid constructs provided a potential A. actinomycetemcomitans/E. coli shuttle plasmid for the development of a genetic transfer system in A. actinomycetemcomitans.
A simple in vivo approach to examine early dental plaque formation in the human mouth and to dete... more A simple in vivo approach to examine early dental plaque formation in the human mouth and to determine the effects of common dietary and oral hygiene procedures on biofilm formation is reported. A custom designed device that fits securely behind the teeth of the mandibular arch provides a surface for microbial colonization. This device is prepared with denture acrylic and can be repeatedly used by the subject, exposing a large and constant surface area for microbial accumulation. Large numbers of oral bacteria colonized the device by 2 h; these increased significantly by 4 h (P &lt; 0.05). Bacterial colonization increased significantly after rinsing with a sucrose solution (P &lt; 0.05) but remained unaffected after rinsing with water, a commercially available fluoride mouthrinse without antimicrobial agents, or brushing with a fluoride dentifrice (P &gt; 0.05). Rinsing with mouthrinses formulated with chlorhexidine, cetylpyridinium chloride or triclosan/copolymer significantly inhibited colonization (P &lt; 0.05). A dose-dependent inhibition was noted with chlorhexidine rinses (P &lt; 0.05). Brushing with a triclosan/copolymer dentifrice significantly inhibited microbial colonization compared with a control (P &lt; 0.05). This simple approach was useful for examining the effects of common dietary and oral hygiene procedures. Significant biofilm inhibitory effects were noted with formulations that demonstrated efficacy in previous clinical studies.
Uploads
Papers by Prem Sreenivasan