The survival of subgingival plaque bacteria in an amine fluoride-containing gel

Changes in white spot lesions following post-orthodontic weekly application of 1.25 per cent fluoride gel over 6 months-a randomized placebo-controlled clinical trial. Part I: photographic data evaluation

Background

White spot lesions (WSLs) are a frequent side-effect of multibracket appliance treatment. The effect of local fluoridation on post-orthodontic WSL is however inconclusive.

Objective

Assessment of WSL changes in response to weekly 1.25 per cent fluoride gel application after multibracket appliance treatment.

Trial design

Randomized, single-centre, double-blind, parallel-group, placebo-controlled study.

Participants

Patients with not less than 1 WSL (modified score 1 or 2) on not less than 1 upper front teeth after debonding.

Interventions

Professional fluoride/placebo gel application during weeks 1-2; self-administered home application (weeks 3-24).

Outcomes

Photographic WSL assessment (dimension and luminance) of the upper front teeth (T0-T5).

Randomization

Random assignment to test (n = 23) or placebo group (n = 23) using a sequentially numbered list (random allocation sequence generated for 50 subjects in 25 blocks of 2 subjects each).

Recruitment

The clinical study duration lasted from March 2011 to September 2013.

Blinding

Unblinding was performed after complete data evaluation.

Numbers analysed

Intent-to-treat analysis set comprising 39 participants (test: n = 21, placebo: n = 18).

Outcome

Dimensional WSL quantification showed limited reliability. Luminance improvement (%) of WSL, however, was seen after 6 months (test/placebo: tooth 12, 24.8/18.0; tooth 11, 38.4/35.4; tooth 21, 39.6/38.3; and tooth 22, 15.2/25.0). No statistically significant group difference existed. Data suggest that WSLs are difficult to measure with respect to reliability and repeatability and methods for monitoring WSLs in clinical trials require improvement/validation.

Harms

Similar adverse events occurred in both groups; none was classified as possibly related to the study product.

Limitations

The number of dropouts was higher than expected and the socio-economic status was not assessed. Furthermore, the unknown level of compliance during the home application phase must be considered as limitation.

Conclusion

Based on the results of this study, no difference could be detected with respect to the development of WSL under post-orthodontic high-dose fluoride treatment.

Registration

The study was registered with ClinicalTrials.gov (Identifier: NCT01329731).

Protocol

The protocol wasn't published before trial commencement.

Anti-plaque agents in the prevention of biofilm-associated oral diseases

The prevention of dental caries and periodontal diseases is targeted at the control of dental plaque. In this context, chemical agents could represent a valuable complement to mechanical plaque control. The active agents should prevent biofilm formation without affecting the biological equilibrium within the oral cavity. Depending on the goals of the preventive measures, various strategies may be considered. Anti-plaque agents with properties other than bactericidal or bacteriostatic activities may be used in primary prevention. In this approach, a modest antiplaque effect may be sufficient or even desirable, as it would decrease the side effects of the active agent. Antimicrobial agents are best indicated in secondary and tertiary prevention, as the objectives are to restore health and to prevent disease recurrence. The rational is to prevent or delay subgingival recolonization by pathogenic micro-organisms. The development of in vitro oral biofilm models certainly represents a major advance for studying and testing oral anti-plaque agents in recent years. The results of these studies have shown that chlorhexidine, hexetidine, delmopinol, amine fluoride/stannous fluoride, triclosan, phenolic compounds, among others, may inhibit biofilm development and maturation as well as affect bacterial metabolism.

Amine fluoride gel affects the viability and the generation of superoxide anions in human polymorphonuclear leukocytes: an in vitro study

Amine hydrofluorides are widely used to prevent caries. As an acidulated gel, they were also studied for their applicability to reduce pathogenic bacteria in periodontal pockets. We assessed the toxicity of this pharmaceutical amine hydrofluoride preparation on human polymorphonuclear leukocytes in vitro by measuring Trypan blue exclusion and the generation of superoxide anions (O2) by the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) after a 3-min contact with gel. Depending on the experimental conditions, gel dilutions up to 1.3 x 10(4) resulted in an increase in Trypan blue-colored cells and liberation of beta-glucuronidase. Dilutions between 3 x 10(4) and 1 x 10(5) augmented the fMLP-mediated O2- generation, which could be prevented by Ca2+ chelation with BAPTA-AM (1,2'-bis (o-aminophenoxyethane-N.N.N'.N'-tetraacetic acid tetra (acetoxymethyl) ester) and ethyleneglycoltetraacetic acid (EGTA) or inhibition of protein kinase C (PKC) with staurosporine and bisindolylmaleimide I. respectively. Compared with data published on the minimal inhibitory concentration for periodontal pathogenic bacteria, the cytotoxicity of amine hydrofluorides on eukaryotic cells is much greater and thus of consequence for their clinical use.

In vitro assessment of the antimicrobial activity of a local sustained release device containing amine fluoride for the treatment of oral infectious diseases

Dental caries and periodontal diseases are chronic infectious diseases caused by oral bacteria. Local sustained release delivery systems extend the time in which the drug is present in the oral cavity, thus enhancing its therapeutic potential while reducing its side effects. Amine-fluorides (AmF) are known anticaries agents and have recently been found to have an antibacterial effect against periodontal pathogens and caries-associated bacteria. The purpose of this in vitro study was to assess the antimicrobial activity of a local sustained release device (LSRD) containing AmF on Streptococcus sobrinus 6715. LSRD was prepared from an ethylcellulose matrix containing AmF. Release kinetics of AmF from the LSRD was measured simultaneously with its antimicrobial activity. The organic amine and the fluoride were released in different kinetics profiles: The fluoride was released faster than the organic amine. The antimicrobial activity of AmF was measured on planktonic bacteria in solution and on bacteria as part of experimental dental plaque. During a 10-day period, the concentration of the released AmF was above its MIC and no bacterial growth was observed. Bacterial counts in the dental plaque were reduced by 1 to 2 log units. Hence, the LSRD containing AmF has the potential to serve as a medicament in prevention and treatment of dental caries and periodontal diseases.