Bactericidal action of bicarbonate ion on selected periodontal pathogenic microorganisms

The anti-plaque effect of high concentration sodium bicarbonate dentifrice on plaque formation and gingival inflammation, irrespective to individual polishing technique and plaque quality

AIM

To assess the anti-plaque effect of a high concentration sodium bicarbonate dentifrice on plaque formation, and gingivitis, as compared to a control toothpaste, irrespective of individual brushing technique and plaque quality.

METHODS

The experimental gingivitis model, with a split-mouth design was used to assess the anti-plaque effect of a high concentration sodium bicarbonate dentifrice on plaque formation. By producing individual fitted trays, the toothpaste was applied in the test quadrant and a control dentifrice in the contralateral. The participants used the individual fitted trays for 1 min every morning and evening, for 21 days. In this period, the participants was only allowed to brush the teeth in the opposite jaw, as usual. Twenty healthy individuals successfully completed the study.

RESULTS

At 21 days, there was no statistically significant difference between test quadrant and control quadrant with regard to plaque indices, gingival index and number of bleeding sites.

CONCLUSION

This study demonstrated that the high concentration sodium bicarbonate dentifrice used did not produce statistically significant anti-plaque effect compared to the control dentifrice, in terms of Plaque- and Gingival Indices, number of bleeding sites or by Quigely and Hein, the Turesky modification Plaque Index, irrespective of brushing technique and individual plaque quality.

TRIAL REGISTRATION

Regional Committee for Medical Research and Ethics, South-East Norway in 2021 (REK.2021/370116).

CLINICAL TRIAL REGISTRATION

NCT05441371 (First registered 09/06/2022, First posted 01/07/2022) ( http://www.

CLINICALTRIALS

gov ). (Retrospectively registered).

Antimicrobial Chemotherapy for Recalcitrant Severe Human Periodontitis

This study evaluated a combined systemic and topical anti-infective periodontal treatment of 35 adults who had experienced ongoing periodontal breakdown following conventional surgical periodontics. The prescribed anti-infective therapy, based on microbiological testing, consisted of a single course of metronidazole plus ciprofloxacin (23 patients), metronidazole plus amoxicillin/clavulanic acid (10 patients), and metronidazole plus ciprofloxacin followed by metronidazole plus amoxicillin/clavulanic acid (2 patients). In addition, the study patients received 0.1% povidone-iodine subgingival disinfection during non-surgical root debridement and daily patient administered oral irrigation with 0.1% sodium hypochlorite. At 1 and 5 years post-treatment, all study patients showed gains in clinical periodontal attachment with no further attachment loss, and significant decreases in pocket probing depth, bleeding on probing, and subgingival temperature. The greatest disease resolution occurred in patients who at baseline harbored predominantly major periodontal pathogens which post-antibiotics became non-detectable and substituted by non-periodontopathic viridans streptococci. The personalized and minimally invasive anti-infective treatment regimen described here controlled periodontitis disease activity and markedly improved the clinical and microbiological status of the refractory periodontitis patients.

Bicarbonate Effects on Antibacterial Immunity and Mucus Glycobiology in the Cystic Fibrosis Lung: A Review With Selected Experimental Observations

The primary defect in cystic fibrosis (CF) is abnormal chloride and bicarbonate transport in the cystic fibrosis transmembrane conductance regulator (CFTR) epithelial ion channel. The apical surface of the respiratory tract is lined by an airway surface liquid layer (ASL) composed of mucin comprising mainly MUC5A and MUC5B glycoproteins. ASL homeostasis depends on sodium bicarbonate secretion into the airways and secretion deficits alter mucus properties leading to airway obstruction, inflammation, and infections. Downstream effects of abnormal ion transport in the lungs include altered intrinsic immune defenses. We observed that neutrophils killed Pseudomonas aeruginosa more efficiently when it had been exposed to sodium bicarbonate, and formation of neutrophil extracellular traps (NETs) by neutrophils was augmented in the presence of increasing bicarbonate concentrations. Physiological levels of bicarbonate sensitized P. aeruginosa to the antimicrobial peptide cathelicidin LL-37, which is present in both lung ASL and in NETs. Sodium bicarbonate has various uses in clinical medicine and in the care of CF patients, and could be further explored as a therapeutic adjunct against Pseudomonas infections.

Effects of Sodium Silicate Complex against Hemorrhagic Activities Induced by Protobothrops mucrosquamatus Venom

Protobothrops mucrosquamatus poses a serious medical threat to humans in Southern and Southeastern Asia. Hemorrhage is one of the conspicuous toxicities related to the pathology of P. mucrosquamatus envenoming. Previous in vitro and in vivo studies showed that a silica-derived reagent, sodium silicate complex (SSC), was able to neutralize hemorrhagic and proteolytic activities induced by pit viper venoms, including Crotalus atrox, Agkistrodon contortrix contortrix and Agkistrodon piscivorus leucostoma. In this study, we validated that SSC could neutralize enzymatic and toxic effects caused by the venom of P. mucrosquamatus. We found that SSC inhibited the hemolytic and proteolytic activities induced by P. mucrosquamatus venom in vitro. In addition, we demonstrated that SSC could block intradermal hemorrhage caused by P. mucrosquamatus venom in a mouse model. Finally, SSC could neutralize lethal effects of P. mucrosquamatus venom in the mice. Therefore, SSC is a candidate for further development as a potential onsite first-aid treatment for P. mucrosquamatus envenoming.

Sodium bicarbonate catheter lock solution reduces hemodialysis catheter loss due to catheter-related thrombosis and blood stream infection: an open-label clinical trial

BACKGROUND

There is no ideal lock solution that prevents hemodialysis (HD) catheter loss due to catheter-related thrombosis (CRT) and catheter-related bloodstream infection (CRBSI). Catheter loss is associated with increased hospitalization and high inpatient costs. Sodium bicarbonate (NaHCO3) demonstrates anti-infective and anticoagulation properties with a good safety profile, making it an ideal lock solution development target.The objective of this study was to determine the safety and efficacy of using sodium bicarbonate catheter lock solution (SBCLS) as a means of preventing HD catheter loss due to CRT and CRBSI.

METHODS

The study took place in a community hospital in Brooklyn, NY, USA. All admitted patients ≥18 years of age who needed HD treatment through CVC were included in the study. 451 patients included in the study were provided SBCLS or NSCLS post-dialysis. Catheter loss due to CRT or CRBSI was evaluated over a period of 546 days.

RESULTS

A total of 452 patients met the criteria; 1 outlier was excluded, 226 were in the NSCLS group and 225 were in the SBCLS group. There were no significant differences between groups in comorbidities at the outset. The NSCLS group had CRT and CRBSI rates of 4.1 and 2.6/1000 catheter days (CD), respectively, compared with 0.17/1000 CD for both outcomes in the SBCLS group. SBCLS patients had a significantly reduced catheter loss rate due to CRT (P < 0.0001) and CRBSI (P = 0.0004). NSCLS patients had higher odds of losing their catheter due to CRT {odds ratio [OR] 26.6 [95% confidence interval (CI) 3.57-198.52]} and CRBSI [OR 15.9 (95% CI 2.09-121.61)] during the study period.

CONCLUSION

The novel approach of using SBCLS was found to be safe and was statistically superior to normal saline in preventing HD catheter loss due to CRT and CRBSI. NaHCO3 solution is inexpensive, readily available in various settings and holds the potential to decrease hospitalization, length of stay and dialysis-related costs.

TRIAL REGISTRATION

Maimonides Medical Center Investigational Review Board, Study IRB 2015-06-25-CIH. ClinicalTrials.gov identifier: NCT03627884.

The efficacy of baking soda dentifrice in controlling plaque and gingivitis: A systematic review

OBJECTIVE

To test the efficacy of a dentifrice containing baking soda (BS), compared with dentifrice without BS for controlling plaque and gingivitis.

MATERIALS AND METHODS

MEDLINE-PubMed and Cochrane-CENTRAL were searched. The inclusion criteria were randomized controlled clinical trials including healthy participants aged 18 years or older. Studies were selected that compared the effect of toothbrushing with a dentifrice with and without BS on the clinical parameters of plaque and gingivitis. Data were extracted from the selected studies, and a meta-analysis was performed.

RESULTS

The search retrieved 21 eligible publications. Among these papers, 43 comparisons were provided, with 23 involving a single-use design and 20 being evaluations with a follow-up. Negative controls were found, or positive controls for which various active ingredients had been used. The included studies showed a moderate overall potential risk of bias and considerable heterogeneity. The meta-analysis of plaque scores from the single-brushing experiments showed that BS dentifrice (BS-DF) was associated with significantly better outcomes than the negative control dentifrices (DiffM -0.20; P < 0.0001; 95% CI: [-0.27; -0.12]) or the positive control dentifrices (DiffM -0.18; P < 0.0001; 95% CI: [-0.24; -0.12]). This finding was only confirmed in studies that used a follow-up design as compared to a negative control (DiffM -0.19; P = 0.01; 95% CI: [-0.34; -0.04]). The indices of gingival bleeding also improved when the comparison was a negative control (DiffM -0.08; P = 0.02; 95% CI: [-0.16; -0.01] and (DiffM -0.13; P < 0.001; 95% CI: [-0.18; -0.08]. However, for the gingival index scores, the meta-analysis did not reveal any significant differences.

CONCLUSION

BS-DF showed promising results with respect to plaque removal in single-use studies. However, the finding was partially substantiated in follow-up studies. Studies that assessed bleeding scores indicated that a small reduction can be expected from BS, relative to a control product.

Bicarbonate Inhibits Bacterial Growth and Biofilm Formation of Prevalent Cystic Fibrosis Pathogens

We investigated the effects of bicarbonate on the growth of several different bacteria as well as its effects on biofilm formation and intracellular cAMP concentration in Pseudomonas aeruginosa. Biofilm formation was examined in 96-well plates, with or without bicarbonate. The cAMP production of bacteria was measured by a commercial assay kit. We found that NaHCO₃ (100 mmol l^-1) significantly inhibited, whereas NaCl (100 mmol l^-1) did not influence the growth of planktonic bacteria. MIC and MBC measurements indicated that the effect of HCO3− is bacteriostatic rather than bactericidal. Moreover, NaHCO₃ prevented biofilm formation as a function of concentration. Bicarbonate and alkalinization of external pH induced a significant increase in intracellular cAMP levels. In conclusion, HCO3− impedes the planktonic growth of different bacteria and impedes biofilm formation by P. aeruginosa that is associated with increased intracellular cAMP production. These findings suggest that aerosol inhalation therapy with HCO3− solutions may help improve respiratory hygiene in patients with cystic fibrosis and possibly other chronically infected lung diseases.

Correcting a Fundamental Flaw in the Paradigm for Antimicrobial Susceptibility Testing

The emergence and prevalence of antibiotic-resistant bacteria are an increasing cause of death worldwide, resulting in a global ‘call to action’ to avoid receding into an era lacking effective antibiotics. Despite the urgency, the healthcare industry still relies on a single in vitro bioassay to determine antibiotic efficacy. This assay fails to incorporate environmental factors normally present during host-pathogen interactions in vivo that significantly impact antibiotic efficacy. Here we report that standard antimicrobial susceptibility testing (AST) failed to detect antibiotics that are in fact effective in vivo; and frequently identified antibiotics that were instead ineffective as further confirmed in mouse models of infection and sepsis. Notably, AST performed in media mimicking host environments succeeded in identifying specific antibiotics that were effective in bacterial clearance and host survival, even though these same antibiotics failed in results using standard test media. Similarly, our revised media further identified antibiotics that were ineffective in vivo despite passing the AST standard for clinical use. Supplementation of AST medium with sodium bicarbonate, an abundant in vivo molecule that stimulates global changes in bacterial structure and gene expression, was found to be an important factor improving the predictive value of AST in the assignment of appropriate therapy. These findings have the potential to improve the means by which antibiotics are developed, tested, and prescribed.

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Standard antimicrobial susceptibility testing (AST) is fundamentally flawed because it is based largely on in vitro efficacy.

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AST performed under conditions that mimic natural infections improves the assignment of appropriate antibiotic therapy.

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In vivo altered susceptibility (IVAS) provides a new paradigm for drug discovery and therapeutic intervention.

Drug testing often excludes potent antibiotics for the treatment of bacterial infections, while frequently identifying antibiotics that are ineffective. However, drug testing under conditions that mimic natural infections succeeded in identifying effective antibiotics, even though these same antibiotics failed standard tests. This work suggests that standard drug-testing may be hindering patient treatment and slowing the process of discovery of new, effective, and safe antibiotics because it disqualifies effective compounds. These findings call for an overhaul of standardized drug testing which hasn't changed in > 50 years.

Management of Oral Sequelae

The purpose of this paper is to enumerate and describe the oral complications that are associated with salivary gland dysfunction. The significance of these oral problems and their related adverse impact on the patient's quality of life are presented. Palliative and therapeutic agents and regimens are discussed, and a suggested protocol for managing the deleterious oral sequelae of salivary gland dysfunction is outlined.

Effectiveness of oral hygiene interventions against oral and oropharyngeal reservoirs of aerobic and facultatively anaerobic gram-negative bacilli

BACKGROUND

Aerobic and facultatively anaerobic gram-negative bacilli (AGNB) are opportunistic pathogens and continue to cause a large number of hospital-acquired infections. AGNB residing in the oral cavity and oropharynx have been linked to nosocomial pneumonia and septicemia. Although AGNB are not considered members of the normal oral and oropharyngeal flora, medically compromised patients have been demonstrated to be susceptible to AGNB colonization.

METHODS

A literature search was conducted to retrieve articles that evaluated the effectiveness of oral hygiene interventions in reducing the oral and oropharyngeal carriage of AGNB in medically compromised patients.

RESULTS

Few studies have documented the use of mechanical oral hygiene interventions alone against AGNB. Although a number of studies have employed oral hygiene interventions complemented by antiseptic agents such as chlorhexidine and povidone iodine, there appears to be a discrepancy between their in vitro and in vivo effectiveness.

CONCLUSION

With the recognition of the oral cavity and oropharynx as a reservoir of AGNB and the recent emergence of multidrug and pandrug resistance in hospital settings, there is a pressing need for additional high-quality randomized controlled trials to determine which oral hygiene interventions or combination of interventions are most effective in eliminating or reducing AGNB carriage.

Hydrogen peroxide: a review of its use in dentistry

Several dentifrices that contain hydrogen peroxide are currently being marketed. The increased use of bleaching agents containing (or generating) H2O2 prompted this review of the safety of H2O2 when used in oral hygiene. Daily exposure to the low levels of H2O2 present in dentifrices is much lower than that of bleaching agents that contain or produce high levels of H2O2 for an extended period of time. Hydrogen peroxide has been used in dentistry alone or in combination with salts for over 70 years. Studies in which 3% H2O2 or less were used daily for up to 6 years showed occasional transitory irritant effects only in a small number of subjects with preexisting ulceration, or when high levels of salt solutions were concurrently administered. In contrast, bleaching agents that employ or generate high levels of H2O2 or organic peroxides can produce localized oral toxicity following sustained exposure if mishandled. Potential health concerns related to prolonged hydrogen peroxide use have been raised, based on animal studies. From a single study using the hamster cheek pouch model, 30% H2O2 was referred to as a cocarcinogen in the oral mucosa. This (and later) studies have shown that at 3% or less, no cocarcinogenic activity or adverse effects were observed in the hamster cheek pouch following lengthy exposure to H2O2. In patients, prolonged use of hydrogen peroxide decreased plaque and gingivitis indices. However, therapeutic delivery of H2O2 to prevent periodontal disease required mechanical access to subgingival pockets. Furthermore, wound healing following gingival surgery was enhanced due to the antimicrobial effects of topically administered hydrogen peroxide. For most subjects, beneficial effects were seen with H2O2 levels above 1%.

Effect of gels containing stannous fluoride on oral bacteria--an in vitro study

The purposes of this investigation were to evaluate and compare the antimicrobial effect of (1) twelve 0.4 per cent stannous fluoride (SnF2) commercial products and (2) different concentrations of SnF2 (range = 0.02 to 3.28 per cent). The antibacterial inhibitory effect of various SnF2 gels was evaluated as to their effectiveness against oral plaque bacteria including strains of S. mutans, S. sanguis, S. sobrinus, A. viscosus, A. actinomycetemcomitans, and B. intermedius. When twelve different commercial preparations of 0.4 per cent SnF2 were compared for inhibitory effect on plaque bacteria, several of the SnF2 preparations were significantly more effective in inhibiting oral bacteria (p < 0.05). With increasing concentration of SnF2, there was a comparable increase in the inhibitory effect on the oral bacteria tested (r2 ranged from 0.867 to 0.996). SnF2 at a concentration of 0.4 per cent had a similar antibacterial effect to 0.12 per cent chlorhexidine. This in vitro study demonstrated that certain SnF2 products are highly effective in inhibiting the growth of bacteria often found in plaque, and this inhibitory effect is directly related to the concentration of the SnF2.

Bicarbonate inhibition of Saccharomyces cerevisiae and Hansenula wingei growth in apple juice

The ability of sodium bicarbonate to inhibit growth of Saccharomyces cerevisiae and Hansenula wingei in apple juice was investigated. Sodium bicarbonate at concentrations of 0.06, 0.12, and 0.24 M was added to pasteurized apple juice that was then inoculated with 10(3) or 10(5) cfu/ml of either yeast. Growth of both yeasts was inhibited by 0.12 M sodium bicarbonate when incubation was at 4 degrees C; 0.24 M sodium bicarbonate caused a slow die off of yeast. At 18 degrees C, H. wingei became more sensitive and died in the presence of 0.12 M sodium bicarbonate, but S. cerevisiae became resistant to 0.24 M sodium bicarbonate. These results could not be attributed to bicarbonate-induced pH elevation or sodium. Potassium and ammonium bicarbonate were also inhibitory, implicating bicarbonate ion as the antimicrobial agent.

Four-year investigation of salt and peroxide regimen compared with conventional oral hygiene

This study of 171 subjects compared the effectiveness of a patient-applied salt and peroxide oral hygiene regimen with the use of conventional oral hygiene methods on clinical measures of periodontal disease, and determined patient compliance with and acceptance of using these two oral hygiene regimens. Results indicated that both regimens, when combined with professional care, were effective in changing clinical measures of periodontal disease to a state favoring periodontal health.

Bicarbonate-based dental powder, fluoride, and saccharin inhibition of dental caries associated with Streptococcus mutans infection of rats

The effects of NaHCO3-based dental powder containing NaF and sodium saccharin on dental caries and Streptococcus mutans recoveries in rats were studied. Weanling specific-pathogen-free Osborne-Mendel (SPFOM) rats were inoculated with S. mutans NCTC-10449S. Four infected groups were topically treated with either demineralized water (DW), a dental powder suspended such that there was 1 part solid per 2 parts DW, 0.073% NaF, or a combination of 0.073% NaF and 0.5% Na-saccharin (Nas). NaF-supplemented DW (at 10 ppm F-) was provided to a 5th group of infected rats as a positive treatment control, but this group was otherwise untreated. A sixth but uninfected group was topically treated with DW. All topical treatments were given once for 1 min daily per rat, for 5 days per week. Animals' teeth were swabbed for recovery of 10449S and total recoverable flora. Recoveries of 10449S were lower from powder-treated rats than from DW-treated rats. This difference approached but did not reach statistical significance. Total caries scores were 51% lower for the dental powder, 36% lower for the topical NaF, 34% lower for the combined NaF-Nas, and 54% lower for the NaF-supplemented drinking water group, all p less than 0.001. While all of the treatments inhibited smooth-surface caries, the dental powder effects, like those for the combined NaF-Nas, and NaF drinking water, were evident in fissure tooth surfaces as well.(ABSTRACT TRUNCATED AT 250 WORDS)

Subcutaneous facial emphysema secondary to use of the Cavi-Jet

A case of subcutaneous facial emphysema secondary to use of the Cavi-Jet air polishing system is reported. Air pressure of the Cavi-Jet may exceed that of other dental instruments such as the air/water syringe or air turbine handpiece. Inadvertent angulation of the nozzle tip into a severe periodontal pocket precipitated this condition, which resolved with no serious sequelae. No treatment other than prophylactic antibiotics was prescribed.

Effect of chewing gum containing sodium bicarbonate on human interproximal plaque pH

The effect of chewing sorbitol gum containing sodium bicarbonate on interproximal plaque pH was determined by use of an ion-sensitive field-effect transistor (ISFET) electrode system with four human volunteers. Plaque pH was lowered by 2 min of chewing of a sucrose-containing toffee. After 20 min, either sodium bicarbonate or control gum was chewed for 10 min, and the pH was followed for an additional 20 min. The minimum pH after toffee chewing was elevated by both the control gum (4.5 +/- 0.3 to 5.2 +/- 0.5) and the sodium-bicarbonate-containing product (4.3 +/- 0.3 to 6.1 +/- 0.6) to levels which were significantly different (p less than 0.01). The rate of rise in pH was 2.6 times faster with the gum containing buffer compared with the control gum. In comparison with the control gum, the sodium bicarbonate gum caused the pH to remain at a higher level, approximately 0.5 pH units, for 20 min after gum chewing. The addition of sodium bicarbonate to gum containing sorbitol markedly enhanced its capacity to cause and maintain an elevation of interproximal plaque pH previously lowered by exposure to fermentable carbohydrate. Sodium bicarbonate may be useful in products designed to reduce the acidogenic challenge to the teeth following food ingestion.

Effects of bicarbonate-based dental powder, fluoride, and saccharin on dental caries and on Streptococcus sobrinus recoveries in rats

The effects of NaHCO3-based dental powder containing NaF and sodium saccharin on dental caries and Streptococcus sobrinus recoveries in rats were studied. Weanling specific-pathogen-free Osborne-Mendel (SPFOM) rats were inoculated with S. sobrinus 6715-13WT. One of six infected groups was topically treated with either demineralized water (DW), a dental powder suspended such that there was 1 part solid per 2 parts DW, 0.073% NaF, 0.5% Na-saccharin (Nas), or a combination of NaF and Nas at the same concentrations. NaF-supplemented DW (at 10 ppm F-) was provided to the 6th group of infected rats as a positive treatment control, but this group was otherwise untreated. A seventh but uninfected group was topically treated with DW. All topical treatments were given once for one min daily per rat, for five days per week. Animals' teeth were swabbed for recovery of 6715-13WT and total recoverable flora. At 37 days after start of treatment, S. sobrinus recoveries were lower only for those rats topically treated with the dental powder (p less than 0.05) by comparison with recoveries from the infected, topical DW-treated group. Caries scores, however, were 42% lower for the groups receiving the dental powder (p less than 0.005), 30% lower for those treated with the combined NaF-Nas (p less than 0.005), and 47% lower for the NaF-supplemented drinking water group (p less than 0.005). The dental powder effects, like those for the combined NaF-Nas and NaF drinking water, were evident on both smooth and fissure tooth surfaces. Both the 10 ppm F- drinking water and the dental powder significantly (p less than 0.005) reduced fissure caries scores below the level elicited by the indigenous mutans-free flora in the DW-treated uninfected rats; however, these reduction were not significantly different from one another. Thus, the 10 ppm F- drinking water and the dental powder equally inhibited not only the S. sobrinus-attributable component of caries but probably also the component of caries attributable to the indigenous oral flora.

Lysozyme-protease-inorganic monovalent anion lysis of oral bacterial strains in buffers and stimulated whole saliva

Similar to Streptococcus mutans, buffer suspensions of Lactobacillus casei, Lactobacillus plantarum, and Fusobacterium nucleatum all undergo cell lysis when treated with the lysozyme-protease-inorganic monovalent anion antibacterial system. For Lactobacillus species treated with lysozyme and proteases at pHs of 4 and 5.3, lysis resulted when a lytic activating concentration of bicarbonate anion followed enzyme treatment. Furthermore, synergistic lysis of these bacteria was noted when lysozyme-protease treatment was followed by bicarbonate anion used in combination with chloride or fluoride anions. Noteworthy, the halides were not active in promoting lysis when used by themselves in the absence of bicarbonate. For F. nucleatum suspended at pH 6.9, lysis was dependent upon the ionic strength of the buffer and resulted when lysozyme-protease treatment of the organism was followed by 100 mmol/L bicarbonate activation. When lysozyme and proteases were omitted from the incubation mixtures and replaced by stimulated whole saliva, pH 5.3, lysis was observed only with L. plantarum and S. mutans, but not with L. casei. The latter could be lysed, however, if suspended in saliva which was diluted several-fold with distilled water. In experiments where lysozyme was selectively depleted from whole saliva by immunoadsorption affinity chromatography, the great majority of the lysis capability of the saliva for L. plantarum was lost, although a significant degree of lysis appeared to be due to salivary factors other than lysozyme. F. nucleatum was also found to lyse in saliva at neutral pH, suggesting that both Gram-positive and Gram-negative oral bacteria may be susceptible to this antibacterial system in vivo.

The use of sodium bicarbonate and hydrogen peroxide in periodontal therapy: a review

The comparative benefits from the use of sodium bicarbonate and hydrogen peroxide over the use of a commercial dentifrice in periodontal therapy is controversial. The consensus of the clinical research indicates that application by patients of sodium bicarbonate and hydrogen peroxide offers no advantage over the preestablished, properly performed home oral hygiene procedures. Any improvements in clinical and microbial parameters generally were attributed to scaling and root planing. The studies that have reported beneficial results with sodium bicarbonate and hydrogen peroxide have used additional antimicrobial agents, concomitant professional application of these substances, and scaling and root planing. In one of these reports, inorganic salts and chloramine-T were delivered subgingivally throughout root-planing procedures, in addition to home application of inorganic salts. Most of these patients also received at least one course of systemic tetracycline therapy. Because this study had no control group, it is impossible to determine whether this program is more effective than are other periodontal therapy programs. A more controlled clinical study involving professional application of sodium bicarbonate, sodium chloride, hydrogen peroxide, and povidone-iodine has shown greater gains in clinical attachment and bone mass than has brushing with toothpaste and water. Again, subgingival scaling and root planing were necessary to attain these results. Because multiple topical agents were applied in both of these reports and systemic antimicrobial agents were used by the Keyes group, it is impossible to determine which agent was responsible for the improvements. Further, professional application may be the crucial factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of oral sequelae

The purpose of this paper is to enumerate and describe the oral complications that are associated with salivary gland dysfunction. The significance of these oral problems and their related adverse impact on the patient's quality of life are presented. Palliative and therapeutic agents and regimens are discussed, and a suggested protocol for managing the deleterious oral sequelae of salivary gland dysfunction is outlined.

Antimicrobial properties of hydrogen peroxide and sodium bicarbonate individually and in combination against selected oral, gram-negative, facultative bacteria

The topical application of hydrogen peroxide (H2O2) and sodium bicarbonate (NaHCO3), individually and in combination, has been used empirically in the treatment of periodontal diseases. In this study, we examined both minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of these disinfectants individually and in combination against selected facultative, Gram-negative oral bacteria in a microtiter dilution assay. The bacteria studied included Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, Eikenella corrodens, and Capnocytophaga gingivalis. These bacteria exhibited MBC (one hr) values ranging from 75 mumol/L to greater than 10 mmol/L and MIC from less than 5 to 500 mumol/L for H2O2. The tested bacteria exhibited MIC values for NaHCO3 of from 23 to 182 mmol/L, and the MBC (one hr) exceeded 728 mmol/L for most of the strains examined. At sublethal (sub-MIC) concentrations, sodium bicarbonate antagonized the ability of H2O2 to inhibit bacterial growth in MIC assays, but sublethal concentrations of H2O2 had no effect on the MIC values of NaHCO3. Lethal concentrations of H2O2 and NaHCO3 exhibited synergistic antimicrobial activity in combination in one-hour bactericidal assays. Since the bactericidal properties of these antimicrobial agents are synergistic, we conclude that it may be rational to use them in combination to treat certain forms of periodontal disease. Also, lower and perhaps safer concentrations of H2O2 can be used in combination with NaHCO3 when oxidative antimicrobial chemotherapy is indicated.

Nutrient and environmental growth factors for eight small-sized oral spirochetes

The present investigation was carried out in order to obtain better information about the growth requirements for small-sized oral spirochetes containing two endoflagella from each cell-end. Eight strains of such spirochetes were isolated from subgingival plaque in patients suffering from advanced marginal periodontitis. The strains were maintained under anaerobic conditions in a fluid basal BHI medium with 15% inactivated rabbit serum, 0.07% Noble Agar and 5 micrograms/ml cocarboxylase. Firstly, the effect of trace amounts of oxygen in the atmosphere and pH in the medium on growth of the spirochete strains were examined. Secondly, the effect of different sera incorporated in the medium was examined, and thirdly, the effect of important growth factors in serum was studied by adding different serum components to the fluid basal medium instead of rabbit serum. Growth was always determined after 4 days' incubation at 35 degrees C, either by counting numbers of spirochete cells in a Petroff-Hauser counting chamber or by measuring the turbidity of the culture spectrophotometrically at 600 nm. There was no difference in growth by using an atmosphere containing 1% oxygen or an anaerobic atmosphere. It was found that serum (rabbit or human) was an essential growth component, and no single growth factor could replace rabbit serum. Only a long chain fatty acid mixture and an amino acid solution could, to a minor extent, stimulate growth compared to the basal medium without rabbit serum. Sodium bicarbonate inhibited growth of all strains. Finally, none of the strains fermented a series of low molecular weight carbohydrates, but all strains produced H2S and indole.

Orthodontic therapy in patients with juvenile periodontitis: clinical and microbiologic effects

The correction of malocclusions in juvenile periodontitis (JP) patients completing periodontal therapy is a problem of increasing clinical concern to orthodontists, since many teeth with severe alveolar bone loss in these patients can now be successfully treated without extraction. In this report, fixed edgewise orthodontic therapy was carried out after the completion of periodontal therapy on four JP patients. The orthodontic therapy included extensive intrusion of teeth severely affected by JP. Phase-contrast microscopic analysis of subgingival plaque from orthodontically treated teeth was used to monitor longitudinally the effects of fixed orthodontic bands on the subgingival flora and also to monitor the efficacy of topical and systemic antimicrobial therapy aimed at suppression of suspected periodontopathic bacteria. Orthodontic movement was completed on most periodontally compromised teeth without significant evidence of additional deterioration in periodontal status. However, within the first 6 months of orthodontic band placement, all patients had significant increases in the number of spirochetes and motile rods in their subgingival flora. Three of the patients also developed high levels of crevicular polymorphonuclear leukocytes around orthodontically treated teeth, indicating significant subgingival inflammation. Intensive antimicrobial measures, including topical inorganic salt applications and systemic tetracycline, were helpful in limiting clinical inflammation and subgingival colonization by periodontopathogens during orthodontic therapy. The results demonstrate that successful orthodontic repositioning can be carried out in treated JP patients. In addition, bacteriologic monitoring and chemotherapeutic suppression of periodontal pathogens may be valuable in the prevention of further destructive periodontal disease activity in periodontitis patients undergoing orthodontic therapy.