Antibacterial and clinical effectiveness of a mouthwash with a novel active system of amine + zinc lactate + fluoride: a randomized controlled trial

OBJECTIVES

To support the daily oral hygiene of patients experiencing gum inflammation, a new mouthwash was developed containing an amine + zinc lactate + fluoride system. In vitro and clinical efficacy was assessed using traditional methods as well as using novel site-specific and subject-specific analyses of the clinical data.

MATERIALS AND METHODS

This mouthwash was evaluated in a 12-h biofilm regrowth assay against a negative control mouthwash and in a 6-month plaque and gingivitis clinical study as compared to a negative control mouthwash. Analyses of healthy versus inflamed sites, visible plaque versus non-visible plaque sites, as well as subject-level evaluations bring new perspectives to the overall performance of this mouthwash and its significance from a patient outcome perspective.

RESULTS

Studies demonstrated that this new mouthwash provided long-term (12-h) antibacterial activity after single application in vitro and reduced clinically all plaque and gingivitis parameters after 3 months and 6 months of use when compared to the negative control mouthwash. Examination of site-level and subject-level data determined that this mouthwash significantly increased the number of healthy sites in the oral cavity and significantly improved the gum health of subjects in the study, as compared to the negative control mouthwash.

CONCLUSIONS

In vitro and clinical research has demonstrated the antibacterial and clinical benefits of this mouthwash containing an amine compound + zinc lactate + fluoride system.

CLINICAL RELEVANCE

Our subject-specific and site-specific analyses provide the dental practitioner with tools that can be used to guide patients who suffer from gingivitis toward optimal product selection and use.

CLINICAL TRIAL REGISTRATION

The trial was registered at ClinicalTrials.gov (reference no. NCT05821712).

Effects of Chlorine Dioxide on Oral Hygiene - A Systematic Review and Meta-analysis

Background

Effective and selective oral rinses are required in the daily medical and dental practice. Currently mouthwashes used have substantial side effects.

Objectives

Our aim was to evaluate the efficacy of chlorine dioxide-containing mouthwashes in comparison with other previously established mouth rinses in healthy adults using oral hygiene indices.

Methods

This work was registered in PROSPERO (CRD42018099059) and carried out using multiple databases and reported according to the PRISMA statement. The search terms used were “chlorine dioxide” AND “oral”, and only randomised controlled trials (RCTs) were included. The primary outcome was the alteration of the plaque index (PI), while the secondary outcomes were the gingival index (GI) and bacterial counts. For the risk of bias assessment, the Cochrane Risk of Bias Tool was used. Statistical analysis for data heterogeneity was performed by Q-value and I²-tests.

Results

364 articles were found in the databases. After the selection process, only five RCTs were eligible for meta-analysis. Data heterogeneity was low. There were no statistical differences in effectiveness between chlorine dioxide and other effective mouth rinses in PI (0.720±0.119 vs 0.745±0.131; 95%; confidence intervals (CIs): 0.487-0.952 vs 0.489-1.001, respectively) and GI (0.712±0.130 vs 0.745±0.131; 95% CIs: 0.457–0.967 vs 0.489–1.001, respectively) and also in bacterial counts.

Conclusion

Chlorine dioxide reduces both plaque and gingival indices and bacterial counts in the oral cavity similar to other routinely used oral rinses, however, the evidence supporting this outcome is very limited. Therefore, further large scale RCTs are needed to decrease the risk of bias.

The Marine Catenovulum agarivorans MNH15 and Dextranase: Removing Dental Plaque

Dextranase, a hydrolase that specifically hydrolyzes α-1,6-glucosidic bonds, has been used in the pharmaceutical, food, and biotechnology industries. In this study, the strain of Catenovulum agarivorans MNH15 was screened from marine samples. When the temperature, initial pH, NaCl concentration, and inducer concentration were 30 °C, 8.0, 5 g/L, and 8 g/L, respectively, it yielded more dextranase. The molecular weight of the dextranase was approximately 110 kDa. The maximum enzyme activity was achieved at 40 °C and a pH of 8.0. The enzyme was stable at 30 °C and a pH of 5–9. The metal ion Sr²⁺ enhanced its activity, whereas NH⁴⁺, Co²⁺, Cu²⁺, and Li⁺ had the opposite effect. The dextranase effectively inhibited the formation of biofilm by Streptococcus mutans. Moreover, sodium fluoride, xylitol, and sodium benzoate, all used in dental care products, had no significant effect on dextranase activity. In addition, high-performance liquid chromatography (HPLC) showed that dextran was mainly hydrolyzed to glucose, maltose, and maltoheptaose. The results indicated that dextranase has high application potential in dental products such as toothpaste and mouthwash.

Treatments for smell and taste disorders: A critical review

A key concern of both the patient and physician is whether treatment is available that will eliminate or quell a given chemosensory disturbance. In cases where obvious oral, nasal, or intracranial pathology is involved, rational straightforward approaches to treatment are often available. In cases where damage to the sensory pathways is secondary to chronic inflammatory disease, trauma, viral invasion, toxic exposure, or unknown causes, the direction for therapy is more challenging. Indeed, many chemosensory disorders, if present for any period of time, cannot be reversed, while others spontaneously remit without any therapeutic intervention. This review assesses the strengths and weaknesses of more than two dozen approaches to treatment that have been suggested for a wide range of taste and smell disorders.

Superficial and Deep Skin Preparation with Povidone-Iodine for Ventriculoperitoneal Shunt Surgery : A Technical Note

Objective

Ventriculoperitoneal (VP) shunt surgery is a common and effective treatment for hydrocephalus and cerebrospinal fluid disorders. Infection remains a major cause of morbidity and mortality after a VP shunt. There is evidence that a deep skin flora microbiome may have a role to play in post-operative infections. In this technical note, we present a skin preparation technique that addresses the issue of the skin flora beyond the initial incision.

Methods

The patient is initially prepped, as standard, with. a single layer of 2% CHG+70% isopropyl alcohol. The novel stage is the ‘double incision’ whereby an initial superficial incision receives a further application of povidone-iodine prior to completing the full depth incision.

Results

Of the 84 shunts inserted using the double-incision method (September 2015 to September 2016), only one developed a shunt infection.

Conclusion

The double incision approach to skin preparation is a unique operative stage in VP shunt surgery that may have a role to play in reducing acute shunt infection.

Effects of selective adaptation on coding sugar and salt tastes in mixtures

Little is known about coding of taste mixtures in complex dynamic stimulus environments. A protocol developed for odor stimuli was used to test whether rapid selective adaptation extracted sugar and salt component tastes from mixtures as it did component odors. Seventeen human subjects identified taste components of "salt + sugar" mixtures. In 4 sessions, 16 adapt-test stimulus pairs were presented as atomized, 150-μL "taste puffs" to the tongue tip to simulate odor sniffs. Stimuli were NaCl, sucrose, "NaCl + sucrose," and water. The sugar was 98% identified but the suppressed salt 65% identified in unadapted mixtures of 2 concentrations of NaCl, 0.1 or 0.05 M, and sucrose at 3 times those concentrations, 0.3 or 0.15 M. Rapid selective adaptation decreased identification of sugar and salt preadapted ambient components to 35%, well below the 74% self-adapted level, despite variation in stimulus concentration and adapting time (<5 or >10 s). The 96% identification of sugar and salt extra mixture components was as certain as identification of single compounds. The results revealed that salt-sugar mixture suppression, dependent on relative mixture-component concentration, was mutual. Furthermore, like odors, stronger and recent tastes are emphasized in dynamic experimental conditions replicating natural situations.

Taste coding after selective inhibition by chlorhexidine

Coding of the complex tastes of ionic stimuli in humans was studied by combining taste confusion matrix (TCM) methodology and treatment with chlorhexidine gluconate. The TCM evaluates discrimination of multiple stimuli simultaneously. Chlorhexidine, a bis-biguanide antiseptic, reversibly inhibits salty taste and tastes of a subset of bitter stimuli, including quinine hydrochloride. Identifications of salty (NaCl, "salt"), bitter (quinine.HCl, "quinine"), sweet (sucrose, "sugar"), and sour (citric acid, "acid") prototypes, alone and as components of binary mixtures, were measured under 4 conditions. One was a water-rinse control and the others had the salt and quinine tastes progressively reduced by treatment with 1 mM chlorhexidine, 3 mM chlorhexidine, and ultimately to zero by elimination of NaCl and quinine.HCl. Treatment with chlorhexidine perturbed identification of salt more than quinine; both were thereafter more often confused with "water" and unidentified when mixed with sucrose or citric acid. All pairwise discriminations that depended on the tastes of NaCl and quinine.HCl deteriorated, and although H(2)O was mistakenly identified as quinine after chlorhexidine, this may have been a decisional bias. Other confusions reflected "unprompted mixture analysis" and an obscuring of salt taste by a less-inhibited stronger quinine or sugar or acid tastes in mixtures. Partial inhibition of the tastes of NaCl and quinine.HCl by chlorhexidine was considered in the context of multiple receptors for the 2 compounds. Discrimination among prototypic stimuli with varying strengths was consistent with a gustatory system that evaluates a small number of independent tastes.

Oral thresholds and suprathreshold intensity ratings for free fatty acids on 3 tongue sites in humans: implications for transduction mechanisms

Multiple putative free fatty acid (FFA) transduction mechanisms have been identified in the oral cavity. They reportedly differ in their distribution on the tongue and each has a unique range of ligand specificities. This suggests that there should be regional differences in sensory responses to varying FFAs. This was assessed through spatial testing with caproic (C), lauric (L), and stearic (S) FFAs among 35 healthy adults. Stimuli were applied to the fungiform (FU), foliate (FO), and circumvallate (CV) papillae with a cotton-tipped applicator. Oral detection thresholds were measured by an ascending, 3-alternative, forced-choice, sip and spit procedure. Intensity ratings were obtained on the general labeled magnitude scale. Nongustatory cues were minimized by testing with the nares blocked, eyes covered, and by masking tactile cues with the addition of gum acacia and mineral oil to the stimuli vehicle. Thresholds were obtained from nearly all individuals at each site, and the concentration was similar across the 3 FFAs. Absolute intensity ratings differed significantly with C > L > S overall and at the CV and FO papillae. At the FU papillae, the L and S ratings were comparable. Ratings were highest at the FU followed by the CV and then the FO papillae. Slopes of the concentration-intensity rating functions were higher for L compared with C and S at the CV papillae as well as both L and C compared with S at the FO papillae. However, overall, slopes were comparable across sites. These findings strengthen evidence for oral FFA perception in humans by replicating threshold sensitivity findings and documenting monotonic scaling ability for these stimuli. Further, they challenge current views on transduction as sensory responsiveness was observed at tongue sites not predicted to support FFA detection.

Cracking taste codes by tapping into sensory neuron impulse traffic

Insights into the biological basis for mammalian taste quality coding began with electrophysiological recordings from "taste" nerves and this technique continues to produce essential information today. Chorda tympani (geniculate ganglion) neurons, which are particularly involved in taste quality discrimination, are specialists or generalists. Specialists respond to stimuli characterized by a single taste quality as defined by behavioral cross-generalization in conditioned taste tests. Generalists respond to electrolytes that elicit multiple aversive qualities. Na(+)-salt (N) specialists in rodents and sweet-stimulus (S) specialists in multiple orders of mammals are well characterized. Specialists are associated with species' nutritional needs and their activation is known to be malleable by internal physiological conditions and contaminated external caloric sources. S specialists, associated with the heterodimeric G-protein coupled receptor T1R, and N specialists, associated with the epithelial sodium channel ENaC, are consistent with labeled line coding from taste bud to afferent neuron. Yet, S-specialist neurons and behavior are less specific than T1R2-3 in encompassing glutamate and E generalist neurons are much less specific than a candidate, PDK TRP channel, sour receptor in encompassing salts and bitter stimuli. Specialist labeled lines for nutrients and generalist patterns for aversive electrolytes may be transmitting taste information to the brain side by side. However, specific roles of generalists in taste quality coding may be resolved by selecting stimuli and stimulus levels found in natural situations. T2Rs, participating in reflexes via the glossopharynygeal nerve, became highly diversified in mammalian phylogenesis as they evolved to deal with dangerous substances within specific environmental niches. Establishing the information afferent neurons traffic to the brain about natural taste stimuli imbedded in dynamic complex mixtures will ultimately "crack taste codes."