- No exact quantification methods for the detection of dental caries so far used in the clinics Disadvantages of diagnostic methods:
- Quantification of tooth cavity is not possible
- With existing radiographs, we cannot distinguish between active and arrested lesions and sometimes between non-cavitated and cavitated lesions.
- Painful and fearful procedures
- Amalgam as filling – if degrades and enters digestive system, can cause problems
- Highly prone to dental fracture during tooth extraction
- Nerve damage during tooth extraction
- Phospholipids were dissolved in a chloroform/methanol (2:1, v/v) mixture, glassbeads were added to the flask and the solution was evaporated to dryness in a rotary evaporator.
- Cholesterol (33 mol%) was dissolved in the same solvent mixture and added additionally to the flask whenever required. The films were further dried in vacuum for 20 h to remove organic residues.
- The thin films obtained were hydrated and swelled for 2 h, gently shaken intermittently, at a temperature above the gel to liquid-crystalline phase transition temperature (Tc) with 5 mM or 10 mM phosphate buffer, pH 6.8–7, and kept in the refrigerator overnight.
- Size reduction was performed at a temperature above Tc by extrusion with a extruder using two-stacked 200 nm polycarbonate membranes
- The liposome dispersions were stored in the refrigerator (4 °C). (waiting for pectin to arrive)
- Purified pectin was dissolved in 5 mM phosphate buffer, pH 7.0 ± 0.1, under stirring at room temperature overnight. Pectin concentrations used for liposome coating were 0.05 and 0.2% (w/w).
- Pectin coated liposomes were prepared by adding 1 ml liposomal dispersion to 4 ml pectin solution under continuous magnetic stirring with such a speed that a swirl could be seen in the pectin solution.
- The liposomal dispersion was added to the pectin solution in a drop wise manner (1.2–5.5 ml/min), which afterwards the mixed suspension was stirred for an additional five minutes with a swirling speed.
- Radiographs are the most used detection aid using the bitewing technique. The aim of the bitewings is to detect proximal caries lesions that cannot be detected in the visual inspection. Problem in Radiography: When an occlusal lesion is detected on a bitewing radiograph, the lesion may have already reached the middle third of dentine and hence beyond the scope of remineralisation interventions [1]. Moreover, radiography cannot distinguish between active and arrested lesions and sometimes between non-cavitated and cavitated lesions. Visual and tactile methods – most conventional and used
- Transillumination can also be an useful tool in the detection of approximal caries. Fiber-optic transillumination (FOTI) is based on the phenomenon of light scattering to increase contrast between normal and carious enamel. The transillumination method may support a treatment decision-making but it is not capable of monitoring dental caries lesions as the bitewing radiographs
- is another method proposed for caries detection. Demineralisation, in theory, creates porosities; the porosities will fill with water and ions from saliva causing electrical conductivity changes [2].The ECM device employs a single, fixed-frequency alternating current, which attempts to measure the ‘bulk resistance’ of tooth tissue [38]. The method has shown promising results showing superior performance to FOTI and radiography in early lesions [3]. However, previous studies have shown the presence of stain as a confounder factor [4]. Another issue is the wide variations on reproducibility, possibly due to inconsistent probe contact with the tooth surface [5].
- QLF is a diagnostic aid for detection, quantification and monitoring of early enamel demineralisation. QLF operates on the principle of enamel autofluorescence, detecting and quantifying the loss of fluorescence associated with demineralisation [6]. The literature on SoproLife® is limited to preliminary results only.
- Another caries detection device based on fluorescence is DIAGNOdent (DD). The DIAGNOdent device consists of 655 nm monochromatic light that is emitted from a tip/sensor and can detect back-scattered fluorescence from the tooth [7]. At 655 nm, the fluorophores have been identified as bacterial porphyrins. Some care is required in the use of Diagnodent in clinical studies, due to problems with stain- and plaque-confounding assessments, and perhaps further work is required before it can be used routinely in clinical studies. The systematic review of Diagnodent [8] confirms the need for caution in both clinical practice and research use.
- Gomez J, Tellez M, Pretty IA, Ellwood RP, Ismail A. Non-cavitated carious lesions detection methods: a systematic review. Community Dentistry and Oral Epidemiology. 2012;41(1):55–66. [PubMed]
- Ricketts DN, Kidd EA, Smith BG, Wilson RF. Clinical and radiographic diagnosis of occlusal caries: a study in vitro. J Oral Rehabil. 1995;22(1):15–20. [PubMed] 36. Pretty IA. Caries detection and diagnosis: novel technologies. J Dent. 2006;34(10):727–739.[PubMed]
- Ricketts DN, Kidd EA, Liepins PJ, Wilson RF. Histological validation of electrical resistance measurements in the diagnosis of occlusal caries. Caries research. 1996;30(2):148–155.[PubMed]
- Longbottom C, Huysmans MC. Electrical measurements for use in caries clinical trials. Journal of Dental Research. 2004;83(Spec No C):C76–79. [PubMed]
- . Cortes DF, Ellwood RP, Ekstrand KR. An in vitro comparison of a combined FOTI/visual examination of occlusal caries with other caries diagnostic methods and the effect of stain on their diagnostic performance. Caries research. 2003;37(1):8–16. [PubMed]
- . Huysmans MC, Longbottom C. The challenges of validating diagnostic methods and selecting appropriate gold standards. J Dent Res. 2004;83(Spec No C):C48–52. [PubMed]
- Lussi A, Imwinkelried S, Pitts N, Longbottom C, Reich E. Performance and reproducibility of a laser fluorescence system for detection of occlusal caries in vitro. Caries research. 1999;33(4):261–266. [PubMed]
- Gimenez T, Braga MM, Raggio DP, Deery C, Ricketts DN, Mendes FM. Fluorescence-based methods for detecting caries lesions: systematic review, meta-analysis and sources of heterogeneity. PloS one. 2013;8(4):e60421. [PMC free article] [PubMed]
- Lussi A, Hibst R, Paulus R. DIAGNOdent: an optical method for caries detection. J Dent Res. 2004;83(Spec No C):C80–83. [PubMed]
Potential of Liposomes for Dental Caries
Recently, nanotechnology and the use of biomimetic nanomaterials have been proposed as new strategies for the prevention and treatment in dentistry. Liposomes are biocompatible nanoparticles that offer innumerable possibilities in that they can be easily designed and tailored to suit a specific application.Jones and coworkers investigated the concept of using liposomes for the delivery of antimicrobial agents, such as Triclosan and chlorhexidine, and found that liposomes could be used to target oral bacteria. These studies demonstrate the potential use of liposomes in the intraoral environment.
Positively charged liposomes as a carrier
Liposomes can be formulated in an attempt to overcome common problems associated with drug therapy in the oral cavity, such as salivary clearance and the nonuniform distribution within the oral cavity. Liposomes can be formulated to have high affinity to the dental enamel to obtain direct targeting to teeth. To minimize salivary clearance, the liposomes should also be able to retain on the dental enamel (bioadhesive liposomes).
From the background research, I found that positively charged liposomes will adhere to the negatively charged hydroxy apatite and dental enamel due to the presence of phosphate groups at neutral pH.
Coating of Liposomes with Pectin
Pectin is negatively charged at neutral pH due to the carboxylic acid groups in the galacturonic residues of the pectin chain. This feature of pectin enables the surface coating of positively charged particles, such as liposomes, by ionic interactions. Pectin is asubstance generally recognized as safe (GRAS) by the American Food and Drug Administration (FDA), and was chosen based on its long and safe history in the food industry as a gelling agent or as a stabilizer, and its mucoadhesive properties in drug delivery systems. Pectin is coated on the liposomes to enable adsorption of teeth and also act as a protective layer
Synthesis of Liposomes coated with Pectin
Liposomes were made according to the standardfilm method.
Characterization of Liposomes
Zeta Sizer will be used to characterize the liposomes, getting the size, pH and zeta potential of the liposomes. I had to go out of town for the characterization, which will be completed after the final presentation and further work will be carried out.Details about Dental Caries
For details about the dental caries, I used KEGG website.
Mostly, Dental caries are caused by Gram Positive bacteria. Environmental factor responsible for the dental caries is dietary sugar. Streptococcus mutans, Lactobacillus are few pathogens which causes dental caries.
Theranostic application of Liposomes
Based on the literature studies, I hypothesize that if the DPPC is also combined with Polycaprolactone membrane, the poly caprolactone core is susceptible to degradation by Gram positive bacteria and hence hydrolyzes the Phosphotidylcholine shell, releasing the antibiotic. The antibiotic I take here is Farnesol. The below scheme from the literature describes the mechanism of release of drug due to bacterial lipase.
I used KEGG Pathway to understand the synthesis of Farnesol. The farnesene is then oxidized to yield farnesol.
For the diagnostic property, the liposome is attached to a flourophore (preferrably rhodamine) that could detect the dental cavity. For instance, the fluorescent intensity decreases if the enamel is prone to cavity, as the pectin coated liposome is adhered to the enamel. The decrease in the auto fluorescence of the enamel will enable us to diagnose earlystage dental cavities.
Inhibition of bacterial growth after liposome administration
The presence of bacterial colonies will be taken from the infected enamel as well as from the enamel that has been treated with Liposome administration and compare the difference.
It would be really great if the liposomes could be mixed with a mouthwash, and the patient gargles with the mouth wash, the dental cavities can be diagnosed as well as treated and protected from further damage of teeth as the pectin coated liposomes acts as a protective layer.One most important aspect of farnesol is that it has a floral smell, which makes our mouth fresh.
Background reading
Types of Diagnostic Methods Available
It is yet to be established whether methods such as QLF and ECM may become a helpful tool in the detection of dental caries in everyday practice.
.REFERENCES
Go back to home page