A review of slow-release fluoride devices

Intraoral medical devices for sustained drug delivery

OBJECTIVES

The oral cavity constitutes an attractive organ for the local and systemic application of drug substances. Oromucosal tablets, gels, or sprays are examples of the formulations applied. Due to the elution through the saliva, the residence time of the formulation at the application site is relatively short. Medical devices placed in the oral cavity, with a reservoir for an active substance, play an important role in solving this problem.

MATERIALS AND METHODS

In this review, we discuss the devices described in the literature that are designed to be used in the oral cavity, highlighting the advantages, disadvantages, and clinical applications of each of them.

RESULTS

Among the intraoral medical devices, special types are personalized 3D-printed devices, iontophoretic devices, and microneedle patches.

CONCLUSION

We anticipate that with the development of 3D printing and new polymers, the technology of flexible and comfortable devices for prolonged drug delivery in the oral cavity will develop intensively.

CLINICAL RELEVANCE

The presented review is therefore a useful summary of the current technological state, when in fact none of the existing devices has been widely accepted clinically.

3D printing of a controlled fluoride delivery device for the prevention and treatment of tooth decay

Dental decay is a highly prevalent chronic disease affecting people from all ages. Clinically, fluoride supplementation is the primary strategy in the prevention of dental decay. However, the current existing self-application formulations such as gels or mouthwashes are rapidly cleared after administration, resulting in modest efficacy even after repeated applications. Therefore, a user-friendly formulation that can provide sustained fluoride release in the oral cavity is of great interest for dental decay prevention. Herein, we report the utilization of fused deposition modelling to fabricate personalised mouthguards, which allow local and prolonged fluoride elution. Composite filaments comprising sodium fluoride and polymers with tuneable hydrophobicity were produced using blends of poly(ε-caprolactone) (PCL) and poly(vinyl alcohol) or poly(ethylene glycol) (PEG). The materials exhibited suitable mechanical properties for dental devices as well as different release kinetics depending on their composition. Ex vivo studies were performed on decayed human teeth using the 3D printed tooth caps that precisely fit the complex geometries of each specimen. A significant elevation of fluoride content in the lesion mineral in contact with the PCL/PEG tooth caps was achieved compared to the ones in contact with solutions mimicking dental care products. In conclusion, this study suggested that a sustained localized drug release of fluoride from personalised 3D printed mouthguards at the device-enamel interface can improve the incorporation of fluoride in the tooth matrix and prevent lesion progression.

Emerging Applications of Drug Delivery Systems in Oral Infectious Diseases Prevention and Treatment

The oral cavity is a unique complex ecosystem colonized with huge numbers of microorganism species. Oral cavities are closely associated with oral health and sequentially with systemic health. Many factors might cause the shift of composition of oral microbiota, thus leading to the dysbiosis of oral micro-environment and oral infectious diseases. Local therapies and dental hygiene procedures are the main kinds of treatment. Currently, oral drug delivery systems (DDS) have drawn great attention, and are considered as important adjuvant therapy for oral infectious diseases. DDS are devices that could transport and release the therapeutic drugs or bioactive agents to a certain site and a certain rate in vivo. They could significantly increase the therapeutic effect and reduce the side effect compared with traditional medicine. In the review, emerging recent applications of DDS in the treatment for oral infectious diseases have been summarized, including dental caries, periodontitis, peri-implantitis and oral candidiasis. Furthermore, oral stimuli-responsive DDS, also known as "smart" DDS, have been reported recently, which could react to oral environment and provide more accurate drug delivery or release. In this article, oral smart DDS have also been reviewed. The limits have been discussed, and the research potential demonstrates good prospects.

The history of public health use of fluorides in caries prevention

AIM

The aim of our study was to chronologically analyse various public health measures of fluoride use in caries prevention.

METHODS

We systematically searched the PubMed database on the preventive role of fluorides in public health, published from 1984 to 2014. The search process was divided into four steps, where inclusion and exclusion criteria were defined. Qualitative methodology was used for the article analysis. In the research process, the described forms of F use, diversity of the described F agents, and the observed population group were analysed.

RESULTS

In our systematic review, 40 relevant reviews were revealed. Fluorides have been used in many different forms, but only a few studies showed their significant role in public health. Water fluoridation was the most important public health measure. In the recent decades, the number of studies on topical fluorides is constantly rising. The most extensively described topical forms of fluorides are professionally applied fluoride agents and fluoride toothpaste for home-use. The use of fluoride containing toothpaste in caries prevention is a safe and successful public health measure (PHM) if their use is widespread, and it is recommended for all. The results on other topical forms of fluorides are insufficient to be suggested as an important PHM.

CONCLUSIONS

The role of fluorides in public health prevention has changed in accordance with the knowledge about the fluoride cariostatic mechanism. Previously the most important pre-eruptive effect of fluorides was supplemented by the post eruptive effect. Abundant evidence exists to show the effectiveness of systemic and topical fluorides.

Intraoral Fluoride-Releasing Devices: A Literature Review

Dental caries still continues to be a problem for majority of the individuals and it can be a serious problem for medically compromised, developmentally disabled and elderly individuals. Water fluoridation, systemic and topical fluorides are used for past many years to supply supplemental fluoride in order to combat dental caries. The latest fluoride research is investigating the use of slow-release devices for the long-term intraoral provision of fluoride. The present review addresses two main types of intraoral fluoride-releasing devices like the copolymer membrane device, glass device containing fluoride and some variations of these devices. These devices can significantly increase the salivary fluoride concentration without substantially affecting the urinary fluoride levels. A significant number of studies have confirmed that intraoral fluoride-releasing devices have great potential for use in preventing dental caries in children, high-caries-risk groups, and irregular dental attenders in addition to a number of other applications. As most of the studies done on these devices are in vitro and in vivo studies, more well-designed clinical trials are necessary to evaluate the results so that these devices can be used clinically.

How to cite this article

Gambhir RS, Kapoor D, Singh G, Singh J, Kakar H. Intraoral Fluoride-Releasing Devices: A Literature Review. World J Dent 2012;3(4):350-354.

The effect of fluoride slow-releasing devices on fluoride in plaque biofilms and saliva: a randomised controlled trial

AIM

To investigate the effect of the fluoride sustained slow-releasing device (FSSRD) on F levels in unstimulated saliva and undisturbed plaque biofilms over 7 days. The investigation also aimed at studying the effect of patient age on fluoride (F) concentrations in dental plaque biofilms and unstimulated saliva while using the FSSRD.

STUDY DESIGN

This was a randomised control double blind cross-over study.

METHODS

Sixty-five participants between the ages of 6-35 years took part in this study. The mean age of all the participants was 19.22 years with 24 participants aged between 6-16 years (mean age=11.8 years) and 41 participants aged between 16-35 years (mean age=23.57 years). Plaque biofilms were collected using a modification of the plaque generating device (MPGD) [Robinson et al., 1997]. During the whole study period, including a 7 day washout period before the first leg, all participants were asked to use only non-fluoridated toothpaste and to avoid where possible high fluoride containing foods or drinks. Whenever possible, the FSSRD/placebo device (PD) was attached to the second permanent molar, while the MPGD was attached to the first permanent molars in the same upper dental quadrant. At the end of each leg of the study whole, mixed unstimulated saliva was collected from all participants and analysed for F concentration.

STATISTICS

Statistical analysis using paired sample t-test was used to compare the results of F level between test and control groups, while, Spearman's correlation coefficient was used to test the relationship between patient's age and plaque weight against F concentration in plaque and saliva.

RESULTS

There was no statistically significant difference in F concentration in plaque and saliva between the test and control groups when analysed using paired sample t-test (p>0.05). There was no correlation between patient's age and F concentration in dental plaque and saliva (p>0.05), in both the test and control groups.

CONCLUSIONS

Our data showed no effect of the FSSRD in raising F concentrations in dental plaque and unstimulated whole saliva after 7 days. Such levels may require longer periods to become established.