Study on the Organoleptic Intensity Scale for Measuring Oral Malodor

The 0–5 organoleptic scale is used widely in breath research and in trials to measure the efficacy of anti-odor agents. However, the precise relationship between odor scores and gas concentrations of target odorants is unknown. The purpose of this study was to relate mean organoleptic scores from odor judges (n = 7) for pure odorants (n = 8) representative of those found in oral malodor. Judges used a common 0–5 scale to report the odor intensity of sample sets in random order of concentration. Regression analysis of data showed that odor score was proportional to the log concentration of odorant, and comparison of slopes showed H2S to be the most significant in terms of odor power. Detection thresholds (mol.dm−3) were: Skatole (7.2 × 10−13) < methylmercaptan (1.0 × 10−11) < trimethylamine (1.8 × 10−11) < isovalerate (1.8 × 10−11) < butyrate (2.3 × 10−10) < hydrogen sulphide (6.4 × 10−10) < putrescine (9.1 × 10−10) < dimethyl disulphide (5.9 × 10−8). The study demonstrates the exponential nature of the olfactory response and shows that any single compound’s contribution to malodor depends on odor power and threshold in addition to concentration.

Halitosis management by the general dental practitioner--results of an international consensus workshop

Clinical investigations on patients suffering from halitosis clearly reveal that in the vast majority of cases the source for an offensive breath odor can be found within the oral cavity (90%). Based on these studies, the main sources for intra-oral halitosis where tongue coating, gingivitis/periodontitis or a combination of the two. Thus, it is perfectly logical that general dental practitioners (GDPs) should be able to manage intra-oral halitosis under the conditions found in a normal dental practice. However, GDPs who are interested in diagnosing and treating halitosis are challenged to incorporate scientifically based strategies for use in their clinics. Therefore, the present paper summarizes the results of a consensus workshop of international authorities held with the aim to reach a consensus on general guidelines on how to assess and diagnose patients' breath odor concerns and general guidelines on regimens for the treatment of halitosis.

Effects of training on odor judges scoring intensity

OBJECTIVE

This pilot study was intended to test whether a training protocol improved validity of odor judges (OJs), with or without experience, and whether odorant types differed in error proneness.

METHODS

The OJs (four experienced, two inexperienced) completed a 4-phase training protocol based on the American Society of Testing and Materials standards (ASTM): (i) introduction to sensory scales, n-butanol reference, sniffing techniques; (ii) pretraining measurements; 20 samples of varying intensities of four unpleasant and three pleasant odorants; (iii) exercises assessing quality, intensity, ranking, and matching; and (iv) post-training measurements.

MAIN OUTCOME MEASURES

Subjects' intensity scores were analyzed as the absolute difference from the 'true' intensity (ASTM n-butanol standard) using repeated measures ANOVA.

RESULTS

Training significantly (P = 0.02) reduced OJ errors. Experienced and novice judges did not differ in average errors (P = 0.99), or in improvement in error from pre- to post-training (P = 0.94). Improvement was consistent from pre- to post-training for all odorants except dimethylsulfide for which errors worsened (P = 0.01). Unpleasant and pleasant odorants differed (P = 0.006) in error. After removing water the effects of water control scores from the pleasant odorants, the difference was not significant (P = 0.26).

CONCLUSIONS

The OJs improved in their ability to assess odor intensity irrespective of previous experience. Training is recommended for all OJs prior to research trials.

Pilot study of a breath test for volatile organic compounds associated with oral malodor: evidence for the role of oxidative stress

BACKGROUND

We performed a pilot study of a new method to identify the volatile organic compounds (VOCs) in breath associated with oral malodor, using gas chromatography and mass spectroscopy (GC/MS).

METHODS

Oral cavity breath was collected from seven patients with oral malodor. Breath samples (150 ml) were concentrated onto sorbent traps and analyzed by GC/MS.

RESULTS

Organoleptic scores ranged from 3.0 to 4.0 (mean = 3.3) on a scale of 0-5. Twenty-four of 30 (80.0%) of the most abundant oral malodor volatile organic compounds (OMVOCs) were alkanes and methylated alkanes. These VOCs are products of oxidative stress, generated by lipid peroxidation of polyunsaturated fatty acids in cell membranes.

CONCLUSIONS

Increased oxidative stress in the oral cavity of patients with oral malodor may account for the increased risk of atherosclerosis, coronary heart disease and stroke associated with periodontal disease. The breath test for OMVOCs could potentially provide an objective new test for the assessment of oral malodor.

Bacteriostatic effects of hyaluronic acid

BACKGROUND

This investigation is one of a series of projects seeking to ascertain whether hyaluronic acid (HA) is therapeutically effective in tissue regeneration procedures. The rationale for these investigations is to test the hypothesis that HA can serve as a bioabsorbable carrier for other substrates as well as itself actively promote the regeneration of tissue.

METHODS

In this paper, we report on the bacteriostatic and bactericidal properties of 3 molecular weight formulations of recombinant HA (low, 141 kD; medium, 757 kD; and high, 1,300 kD) on selected oral and non-oral microorganisms in the planktonic phase. Three concentrations of each HA formulation were screened, 0.5, 1.0, and 2.0 mg/ml, using a standard broth culture assay.

RESULTS

Recombinant HA exerted varied bacteriostatic effects on all the bacterial strains tested depending on its molecular weight (MW) and concentration. The high concentrations of the medium MW HA had the greatest bacteriostatic effect, particularly on the Actinobacillus actinomycetemcomitans, Prevotella oris, Staphylococcus aureus, and Propionibacterium acnes strains. The 1.0 mg/ml concentration of high MW HA had the greatest overall bacteriostatic effect, inhibiting the growth of all 6 bacterial strains tested. Among the bacterial strains studied, HA was found to have no bactericidal effects, regardless of concentration or molecular weight.

CONCLUSIONS

The results of this study suggest that HA in the MW range of 1,300 kD may prove beneficial in minimizing bacterial contamination of surgical wounds when used in guided tissue regeneration surgery.

Detecting and treating oral and nonoral malodors

This article suggests methods on how to detect and treat the various oral and nonoral malodor conditions with which patients present. These conditions are separated into those emanating from the nasal passage, sinuses and upper respiratory sources; the mouth; the tongue; the oropharynx; the lower respiratory tract; and the lungs. Foul odors also develop as a result of systemic and gastrointestinal disorders and diseases, as well as the normal breakdown of odiferous ingested foods. The available detection methods are described and future methods are suggested. The overall conclusions made from this review are that currently available management methods will be able to treat most cases. A careful, knowledgeable clinician can usually determine the patient's problem by the use of a thorough history and examination. Occasionally medical consults will be needed; and, in these cases, the approach that must be taken is a combined treatment approach. For example, effective therapy might require a combination of periodontal disease treatment, correction of dental restoration-based food traps and a rigorous daily mechanical debridement of the tongue. The above treatments will often have to be supplemented by the most appropriate mouthwash for the patient's specific condition. Finally, this article hopes to encourage manufacturers of "halitosis products" to support and conduct well-designed clinical trials on their products so that the field is advanced and treatments become more predictable.

The effects of oral rinses on halitosis

Oral rinses are increasingly becoming an important treatment option for halitosis. There are few products on the market that have been thoroughly evaluated in clinical trials designed to test for the long-term efficacy of mouthrinses in the management of this disorder. This review looks at some of the potential causes and detection methods or oral malodor along with the bacterial, microbiological and biochemical processes involved. The article presents the available literature on clinical trials evaluating the efficacy and mechanisms of action of the different types of oral rinses used in the reduction of plaque and gingivitis, in addition to rinse studies geared more specifically to the treatment of halitosis.

The inhibiting effect of aqueous Azadirachta indica (Neem) extract upon bacterial properties influencing in vitro plaque formation

The purpose of this investigation was to examine the inhibitory effects of aqueous extracts derived from the bark-containing sticks (Neem stick) of Azadirachta indica upon bacterial aggregation, growth, adhesion to hydroxyapatite, and production of insoluble glucan, which may affect in vitro plaque formation. Neem stick extracts were screened for minimal bacterial growth inhibition (MIC) against a panel of streptococci by means of a broth dilution assay. Initial bacterial attachment was quantified by the measurement of the adhesion of 3H-labeled Streptococcus sanguis to saliva-conditioned synthetic hydroxyapatite. The effect of the Neem stick extract upon insoluble glucan synthesis was measured by the uptake of radiolabeled glucose from 14C-sucrose. Aggregating activity of the Neem stick extracts upon a panel of streptococci was also examined. No inhibition of bacterial growth was observed among the streptococcal strains tested in the presence of < or = 320 micrograms/mL of the Neem stick extract. The pre-treatment of S. sanguis with the Neem stick extract or the gallotannin-enriched extract from Melaphis chinensis at 250 micrograms/mL resulted in a significant inhibition of the bacterial adhesion to saliva-conditioned hydroxyapatite. Pre-treatment of saliva-conditioned hydroxyapatite with the Neem stick or gallotannin-rich extract prior to exposure to bacteria yielded significant reductions in bacterial adhesion. The Neem stick extract and the gallotannin-enriched extract from Melaphis chinensis inhibited insoluble glucan synthesis. Incubation of oral streptococci with the Neem stick extract resulted in a microscopically observable bacteria aggregation. These data suggest that Neem stick extract can reduce the ability of some streptococci to colonize tooth surfaces.

E-test: a new technique for antimicrobial susceptibility testing for periodontal microorganisms

The purpose of the study was to validate the Epsilometer test (E-test) method for antimicrobial susceptibility testing of selected periodontopathic microorganisms using the agar dilution method as a standard. The E-test has been developed to provide a direct quantification of antimicrobial susceptibility of microorganisms. The device consists of a predefined, continuous, and exponential gradient of antibiotic concentrations immobilized along a rectangular plastic test strip. After 48 hours incubation a drop-shaped inhibition zone intersects the graded test strip at the inhibitory concentration (IC) of the antibiotic. Twenty-two subgingival plaque samples from periodontitis sites were plated on trypticase soy agar supplemented with 5% rabbit blood or 5% sheep blood and trypticase soy agar supplemented with vancomycin and bacitracin. A total of 60 strains of key periodontal pathogens (Prevotella intermedia, Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Eikenella corrodens, Campylobacter rectus, and Capnocytophaga) isolated from 22 sites of 12 patients were studied. The antibiotics tested were clindamycin, metronidazole, tetracycline, ciprofloxacin, cefoxitin, and ampicillin at concentrations above and below the achieved blood or gingival crevicular fluid levels. As a standard reference the minimal inhibitory concentrations (MICs) were determined using the agar dilution method. MICs were compared with ICs determined using the E-test method. The results showed an agreement ranging from 67% to 100%; sensitivity ranging from 75% to 100%; predictability ranging from 56% to 100% and specificity ranging from 33% to 96%. The E-test ICs for ampicillin, cefoxitin, and metronidazole against the Gram-negative capnophilic and microaerophilic rods and the black-pigmented anaerobic rods ICs for ampicillin, clindamycin, metronidazole, and tetracycline showed a high percentage of agreement with the agar dilution MICS.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia following subgingival irrigation and scaling and root planing

The purpose of this study was to determine the incidence of bacteremia after a single professional subgingival irrigation with a 0.12% chlorhexidine gluconate mouthrinse (CHX) as well as after a subsequent scaling and root planing (S/RP) during the same visit. Thirty subjects each with at least 1 site that probed 4 mm or more and bled on probing were randomly assigned to the following groups: 1) irrigation with 0.12% CHX; 2) irrigation with sterile water; and 3) non-irrigated controls. To begin the study blood was drawn just before and 2 minutes after irrigation. Thirty minutes later, blood was drawn again just before and 2 minutes after S/RP at the same site. Specimens were cultured for anaerobic and aerobic microorganisms using standard cultural techniques. Eighteen blood cultures from 15 subjects yielded positive cultures resulting in 23 isolates. Gram-positive rods comprised 34.8% of the total isolates; Gram-positive cocci 34.8%, Gram-negative rods 21.7%, and Gram-negative cocci 8.7%. In the CHX group, bacteremia was detected in 5 subjects after irrigation and in 2 other subjects after S/RP. In the water group, bacteremia was detected in one subject after irrigation and in 4 subjects after S/RP. The control group had 3 bacteremias after S/RP. There was no significant difference between the incidence of bacteremia associated with irrigation by CHX or sterile water (P = 0.141). There was also no significant difference in the incidence of bacteremia after S/RP between the CHX and sterile water irrigation groups and in patients who did not receive irrigation (control group) (P = 0.88).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and microbiological patterns of adults with periodontitis

Although current data suggest that periodontitis may actually be multiple diseases each with varying responses to therapy, little evidence exists to support this theory in adult patients. This report describes the design and initial findings of a longitudinal field trial involving the diagnosis and treatment of adult and refractory periodontitis patients in private practice. Adult patients (N = 221) who met specific clinical criteria were selected from the private practices of 22 periodontists. Clinical characteristics were recorded and subgingival plaque samples were sent to microbiology laboratories at either UCLA or The University of Texas Health Science Center at San Antonio (UTHSCSA). Samples were processed according to protocols standardized between the 2 centers. Five different combinations of the initial clinical and microbial findings were evaluated for patterns in the data by means of cluster analysis. Plaque, bleeding on probing, bone loss scores, probing depth distributions, and microbial findings produced multiple cluster solutions. Solutions involving 6 clusters explained 39.4% to 76.4% of the variation between patients and produced ratios for variation between clusters to variation within clusters of 5.2 to 15.3. The optimal cluster solution incorporated both clinical and microbial findings, with some clusters characterized by high plaque and moderate bleeding on probing and bone loss, whereas others had low plaque but high bleeding on probing and bone loss. Microbial findings of each cluster exhibited distinct patterns with some clusters having a high prevalence (83% to 100%) of specific target bacterial species while other clusters had an absence of these species.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid antimicrobial resistance screening method for Bacteroides intermedius

The purpose of the study was to validate a rapid resistance screening (RRS) method for antimicrobial susceptibility testing of a selected periodontopathic microorganism using the standard broth dilution method as a control. Twenty-five subgingival plaque samples from gingivitis or periodontitis sites were plated on Trypticase soy agar supplemented with 5% rabbit blood with antibiotic discs (RRS method) and without (control). The antibiotics tested were: Augmentin, clindamycin, erythromycin, metronidazole, penicillin G and tetracycline hydrochloride. Bacteroides intermedius isolated from both groups of plates were placed onto antibiotic supplemented Trypticase soy broth. The antibiotic susceptibilities of B. intermedius isolated from the plates with antibiotic discs and the standard broth method were compared. The results showed high sensitivity and predictability for the RRS method compared with the control. The percentage of agreement was: 100% for Augmentin 30 micrograms, clindamycin 2 micrograms and tetracycline 30 micrograms; 96% for erythromycin 15 micrograms, metronidazole 80 micrograms and penicillin 10 IU; 92% for penicillin 2 IU; 88% for erythromycin 2 micrograms and 84% for tetracycline 5 micrograms. The results of this study document the feasibility of the RRS method for testing antimicrobial resistance of whole samples if its efficacy can be demonstrated for other bacteria. This method may be a quick and useful test for the periodontal practitioner in determining the antibiotic susceptibility of periodontal plaque pathogens.

Gingival enhancement in fixed prosthodontics. Part II: Microbiologic findings

This study assessed the changes of the subgingival/marginal microflora during fixed prosthodontic procedures and evaluated the effect of adjunctive rinsing with 0.12% chlorhexidine on the subgingival/marginal microflora during fixed prosthodontic treatment. Thirty patients scheduled for fixed prosthodontics were randomly assigned to either rinsing with 15 ml of tap water b.i.d. (control) or rinsing with 15 ml of 0.12% chlorhexidine gluconate b.i.d. (experimental). Subgingival and marginal plaque was analyzed at baseline, before crown preparation (2 weeks), before crown cementation (5 weeks), and 2 weeks after cementation (7 weeks). The fixed prosthodontic procedures alone altered the subgingival and marginal microbiota toward a more health-associated flora. Adjunctive rinsing twice daily with 0.12% chlorhexidine had a significantly greater effect in reducing putative periodontal pathogens compared with the control regimen. This medication was a useful adjunct to regular oral hygiene during fixed prosthodontic procedures by permitting the establishment and maintenance of a microflora compatible with periodontal health.

Clinical and microbiological effects of subgingival and gingival marginal irrigation with chlorhexidine gluconate

Recent interest in the local delivery of antimicrobial and anti-inflammatory agents has stimulated interest in the efficacy of various treatment regimens. Chlorhexidine gluconate (CHX) delivered daily by home-applied marginal irrigation as a 0.04% solution in combination with a single professional irrigation of 0.12% CHX was tested over a 3-month period. Sixty periodontal maintenance patients each having at least 2 pockets greater than or equal to 4 mm probing depth, and bleeding on probing were assigned to either Group 1: one professional subgingival 0.12% CHX (Peridex) irrigation (Perio Pik) followed by adjunctive daily home marginal 0.04% CHX irrigation (Pik Pocket); Group 2: one professional subgingival 0.12% CHX irrigation followed by adjunctive daily home marginal water irrigation; Group 3: one professional subgingival water irrigation followed by adjunctive daily home marginal water irrigation; or Group 4: control. At baseline and 3 month visits, subgingival plaque samples were taken from 2 sites per patient. Cultural microbiological analysis was performed using non-selective and selective media. Plaque Index, Gingival Index, pocket probing depths, and gingival recession were assessed. Scaling and root planing (supportive periodontal treatment) was provided for each patient followed by subgingival irrigation as outlined above. At 3 months the Gingival Index and pocket probing depths were both significantly reduced (P less than .05) in all irrigation groups compared to baseline. There were no significant changes in clinical parameters in the control group from baseline to 3 months. In Group 1 the GI was significantly reduced (P less than .05) compared to Group 4 at 3 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of subgingival irrigation on bacteremia following scaling and root planing

The purpose of this study was to determine the effects of professional subgingival irrigation, together with subsequent patient administered home marginal irrigation, on the incidence of bacteremia after scaling and root planing (Sc/RP). A total of 60 periodontal maintenance patients were assigned to either Group 1: subgingival irrigation, with 0.12% CHX and daily marginal irrigation with 0.04% CHX; Group 2: subgingival irrigation with 0.12% CHX and daily marginal irrigation with water; Group 3: subgingival and daily marginal irrigation with water; Group 4: Non-irrigation (control). Patients entered the study after receiving a thorough periodontal maintenance appointment including a complete examination, Sc/RP, and standard oral hygiene instruction. Blood samples were taken at the 3-month visit before and after Sc/RP. Microbiological culturing was done using the Septi-Chek system, selective and non-selective media. Results from 54 patients showed that bacteremia was detected prior to Sc/RP in 2 patients and after Sc/RP in 10 patients. No significant effect by treatment regimens on post Sc/RP bacteremia could be detected. The organisms isolated included Eubacterium lentum, Propionibacterium acnes, Streptococcus species, Neisseria species, Candida albicans, Staphylococcus species, and un-identified Gram-negative rods.

Irrigation with 0.06% chlorhexidine in naturally occurring gingivitis. II. 6 months microbiological observations

In an examiner blind positive/negative controlled 6-month study, the efficacy of supragingival irrigation with 0.06% chlorhexidine gluconate on the marginal and subgingival microflora in naturally occurring gingivitis was evaluated. The 222 patients enrolled in the study were assigned to one of four groups: Group 1: Once daily irrigation with 300 ml water followed by irrigation with 200 ml 0.06% chlorhexidine gluconate (experimental); Group 2: Twice daily rinsing with 15 ml 0.12% chlorhexidine (positive control); Group 3: Once daily irrigation with 500 ml water (irrigation control) and Group 4: Sodium fluoride dentifrice for normal oral hygiene only (negative control). All groups received the same sodium fluoride dentifrice for tooth brushing. All patients received a supra- and subgingival oral prophylaxis after baseline examination and at the end of the investigation. Plaque samples were analyzed from 105 patients at baseline, 93 patients at 3 months and 88 patients at 6 months. The 6-months results demonstrated that, when compared with tooth brushing alone, adjunctive supragingival irrigation with 0.06% chlorhexidine gluconate was most effective by significantly reducing (P less than or equal to 0.008) both log10 CFU and % of Gram-negative anaerobic rods and black-pigmented Bacteroides. Chlorhexidine rinse also significantly (P less than or equal to 0.008) reduced log10 CFU of black-pigmented Bacteroides at 6 months. Both chlorhexidine regimens significantly (P less than or equal to 0.008) increased the % of Gram-positive facultative cocci compared to water irrigation at 3 months. Water irrigation had a limited effect on any of the assessed bacterial groups (log10 CFU and %).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of 0.12% chlorhexidine on bacterial recolonization following periodontal surgery

Bacterial plaque accumulation following periodontal surgery has been directly associated with delayed and altered surgical wound healing. Successful antimicrobial treatment following periodontal surgery depends upon the elimination and suppression of wound associated microorganisms. Highly effective antimicrobials should also prevent recolonization of periodontopathogens. In this investigation, the antimicrobial effect of a 0.12% chlorhexidine gluconate mouthrinse (Peridex) on bacterial recolonization after periodontal surgery was determined. A double-blind, randomized, placebo-controlled study was carried out on 40 patients for 6 weeks. Patients with moderate periodontitis (AAP Class III) underwent osseous periodontal flap surgery in one quadrant. Subgingival and marginal plaque samples from the surgery area were taken prior to surgery and 2 and 6 weeks postoperatively. General descriptive bacteriological cultural analysis and assays for specific microbial populations were carried out. During the 6 weeks of mouthrinse use, patients using chlorhexidine had significant reductions over placebo (P less than 0.05) in the number of total Gram-positive facultative cocci, streptococci (85.8%); Gram-positive facultative rods, primarily Actinomyces (91.7%); Capnocytophaga (97.6%) and Gram-negative anaerobic rods (94.5%). Few black pigmented Bacteroides or Actinobacillus actinomycetemcomitans were found prior to surgery or any time postoperatively. In the chlorhexidine group, 6 weeks post surgery, streptococci were the predominant bacterial group in the sampled plaque. Quantitatively, the distribution of bacteria, after 2 and 6 weeks of mouthrinse use, was consistent with a young, less mature plaque. A previous study demonstrated that this plaque was associated with clinical health.