Bioactive Materials for Caries Management: A Literature Review

Researchers have developed novel bioactive materials for caries management. Many clinicians also favour these materials, which fit their contemporary practice philosophy of using the medical model of caries management and minimally invasive dentistry. Although there is no consensus on the definition of bioactive materials, bioactive materials in cariology are generally considered to be those that can form hydroxyapatite crystals on the tooth surface. Common bioactive materials include fluoride-based materials, calcium- and phosphate-based materials, graphene-based materials, metal and metal-oxide nanomaterials and peptide-based materials. Silver diamine fluoride (SDF) is a fluoride-based material containing silver; silver is antibacterial and fluoride promotes remineralisation. Casein phosphopeptide-amorphous calcium phosphate is a calcium- and phosphate-based material that can be added to toothpaste and chewing gum for caries prevention. Researchers use graphene-based materials and metal or metal-oxide nanomaterials as anticaries agents. Graphene-based materials, such as graphene oxide-silver, have antibacterial and mineralising properties. Metal and metal-oxide nanomaterials, such as silver and copper oxide, are antimicrobial. Incorporating mineralising materials could introduce remineralising properties to metallic nanoparticles. Researchers have also developed antimicrobial peptides with mineralising properties for caries prevention. The purpose of this literature review is to provide an overview of current bioactive materials for caries management.

An In Vitro Evaluation of Remineralization Potential of Functionalized Tricalcium Phosphate Paste and CPP-ACPF on Artificial White Spot Lesion in Primary and Permanent Enamel

Aim

Investigation and evaluation of remineralization potential of functionalized tricalcium phosphate paste (fTCP) and casein phosphopeptide-amorphous calcium phosphate (CPP-ACPF) paste on artificially created white spot lesion on human primary and permanent enamel through scanning electron microscopy and microhardness assessment.

Materials and methods

Sixty freshly extracted primary and permanent teeth were selected and artificial white spot lesion were created by using standardized demineralizing solution. Remineralization was carried out using the test pastes. The assessment of demineralization and remineralization was done through a scanning electron microscope and microhardness assessment.

Results

Among the three groups, fTCP shows significantly higher increase in mean microhardness (p < 0.001) through ANOVA and the LSD post hoc test when compared to CPP-ACPF and control group. Also, the unpaired t-test showed that mean change in microhardness in permanent teeth was significantly higher than primary teeth in different time intervals for both experimental groups. Surface morphology was assessed through a scanning electron microscope.

Conclusion

Based on the results of the current study, f-TCP showed comparatively more remineralization potential than CPP-ACP with fluoride.

How to cite this article

Bhadoria N, Gunwal MK, Kukreja R, et al. An In Vitro Evaluation of Remineralization Potential of Functionalized Tricalcium Phosphate Paste and CPP-ACPF on Artificial White Spot Lesion in Primary and Permanent Enamel. Int J Clin Pediatr Dent 2020;13(6):579–584.

Fluoride release and remineralizing potential of varnishes in early caries lesions in primary teeth

This study evaluated the fluoride (F) release and remineralizing potential of varnishes containing sodium fluoride (5% NaF), 5% NaF with CPP-ACP and 5% NaF with TCP in early caries lesions in primary teeth. To determine the F release at 1, 4, 6, 24, 72, and 168 hr, strips were covered with the varnishes and immersed in purified water (n = 7). The varnishes and purified water (negative control) were applied on enamel blocks with early caries lesions (n = 16). Enamel blocks were stored in artificial saliva and submitted to a pH-cycling. The area of enamel hardness loss (ΔS) was analyzed by microhardness, lesion depth by polarized light microscopy (PLM) and the chemical analysis by Energy-dispersive X-ray spectroscopy. Data were submitted to Shapiro-Wilk, two-way and one-way ANOVA, Tukey and paired t-tests (α = 5%). All varnishes released F, but 5% NaF with CPP-ACP had the highest release at 4, 6, 24, and 72 hr (p < .05) followed by 5% NaF with TCP and 5% NaF. No significant difference in ΔS was observed among varnishes (5% NaF = 4,098.4 ± 1,407.9; 5% NaF with CPP-ACP = 4,164.0 ± 1,019.3; 5% NaF with TCP = 4,183.2 ± 1,527.2; p = .999), but all of them differed from the negative control group (6,757.8 ± 2,274.7; p < .001). Lesion depth was lower in varnishes groups compared to negative control (% reduction: 5% NaF = 41.8%, 5% NaF with CPP-ACP = 38.8%, and 5% NaF with TCP = 36.3%; p < .001). Similar Ca, P, and Ca/P ratio percentages among groups and F was not detected after the treatments. All fluoride varnishes showed potential to enhance remineralization of early caries lesions in primary teeth.

Quantitative Analysis of Remineralization of Artificial Carious Lesions with Commercially Available Newer Remineralizing Agents Using SEM-EDX- In Vitro Study"

INTRODUCTION

The basic principle of remineralization is by advocating a biological or non-invasive approach rather than the surgical approach for early enamel lesions. There are relatively newer products available for remineralization, latest being the resin-infiltration technique, commercially available as Icon.

AIM

The aim of the study was to evaluate the remineralizing potential of Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP), Vantej and Icon by the quantitative evaluation of mineral gain.

MATERIALS AND METHODS

Seventy eight maxillary premolars were decoronated at Cemento-Enamel Junction (CEJ) and then sectioned mesio-distally using diamond disc into two halves. Mineral content of the sound specimens were recorded using Energy Dispersive X-ray (EDAX) micro-analyser. The samples were then subjected to demineralization by using demineralizing solution. The samples were grouped (n=26) based on the remineralizing agent used, Group 1: Vantej, Group 2: CPP-ACP, Group 3: Icon. After the application of remineralizing agent, the mineral content was measured using EDAX.

RESULTS

After remineralization, there was a significant difference between the groups when calcium and phosphorous ratios (Ca:P) were compared, showing greater potential of remineralization for CPP-ACP followed by Vantej and Icon group.

CONCLUSION

CPP-ACP performed better than Vantej and Icon in remineralizing the demineralized enamel.

Dentifrice pH but not consistency may affect fluoride uptake in plaque

OBJECTIVE

Test the ability of acidic fluoridated solutions to enhance fluoride (F) bound on bacteria (1) and the effect of dentifrice consistency on plaque fluid F uptake (2).

METHODS

(1) Streptococcus mutans isolates were grown in BHI medium (37°C/18h). Bacteria were washed either with EDTA or CaCl2 both at 1mM to remove or add calcium, respectively. Pellets were incubated with 12 mM NaF at pH 4.5 or 7 for 1 min and F was quantified in the lysates and supernatants with the electrode, after HMDS-facilitated diffusion. (2) A randomized, double-blind, crossover clinical trial was performed in three phases with nineteen adults (20-35 years) that used one of the dentifrices: commercial toothpaste (1100 ppm F, pH7.0 and conventional viscosity (Sorriso Fresh(®))); experimental liquid dentifrice (ELD) (1100 ppm F, pH7.0 and low viscosity [1.1% carboxymethylcellulose (CMC)]) and ELD (1100 ppm F and high viscosity pH7.0 (2.2% CMC)). F concentration in plaque fluid was analyzed using an inverted F electrode.

RESULTS

(1) Significantly higher F amounts were detected in the lysates of bacteria incubated with NaF solution at pH4.5 compared to the supernatant, which was not seen at pH7.0, being this effect calcium-dependent. (2) Significantly higher F concentrations in plaque fluid were found 1h after toothbrushing compared to 12h, but no significant differences were seen among the toothpastes.

CONCLUSIONS

F at low pH binds more efficiently to S. mutans than at neutral pH and dentifrice viscosity does not interfere in plaque fluid fluoride incorporation.

CLINICAL SIGNIFICANCE

pH of the dentifrice but not consistency may be important to F uptake in plaque.

Mechanisms of action of fluoridated acidic liquid dentifrices against dental caries

OBJECTIVE

This study attempted to clarify the mechanisms of action of fluoridated acidic liquid dentifrices against dental caries.

DESIGN

In the in vitro leg, enamel specimens were submitted to a pH-cycling model, treated with distinct dentifrices (0, 550 μgF/g pH 4.5 and pH 7.0, 1100 or 5000 μgF/g pH 7.0) and analyzed using hardness. Alkali-soluble fluoride (F) deposition was quantified on pre-demineralized specimens treated with the dentifrices. In the clinical leg, 2-to-4-year-old children who had been using liquid dentifrices for 6 months (550 μgF/g pH 4.5 or pH 7.0 or 1100 μgF/g pH 7.0) had their plaque samples collected 5 and 60 min after the last brushing. Fluoride uptake in whole plaque was evaluated.

RESULTS

The reduction of the pH had a partial preventive effect on subsurface hardness loss only. [F] had a significant influence on the deposition of fluoride, surface and subsurface hardness loss. In vivo, the reduction of the pH was able to significantly increase plaque F uptake, leading to similar levels as those found for the neutral dentifrice containing twice [F].

CONCLUSION

The results obtained from in vitro studies whose design does not include the presence of dental plaque should be interpreted with caution.

The dentist's role in promoting community water fluoridation: a call to action for dentists and educators

BACKGROUND AND OVERVIEW

Community water fluoridation is an important public health intervention that reduces oral health disparities and increases the health of the population. Promotion of its safety and effectiveness is critical to maintaining its widespread acceptance and ensuring its continued use. Dentists are a potentially important source of knowledge regarding the oral health benefits and safety of water fluoridation. However, few dentists regularly discuss fluorides, and water fluoridation in particular, with patients. The authors aim to describe and discuss the role and importance of dentists' promotion of public water fluoridation, barriers to dentists' involvement and some approaches that might influence dentists to promote water fluoridation more actively.

CONCLUSIONS AND PRACTICE IMPLICATIONS

Ongoing promotion of fluoridation by dentists is a key factor in ensuring sustained municipal water fluoridation. However, current undergraduate dental curricula do not adequately prepare dentists for this role, and continuing dental education may be insufficient to change clinical practice. Although smoking-cessation literature can shed some light on how to proceed, changing dentists' practice behavior remains a largely unstudied topic. Dental associations are a key resource for dentists, providing information that can assist them in becoming advocates for water fluoridation.

Fluoride plus functionalized β-TCP: a promising combination for robust remineralization

With more than 50 years of clinical success, fluoride serves as the gold standard agent for preventing tooth decay. In particular, the action of fluoride facilitates saliva-driven remineralization of demineralized enamel and alters solubility beneficially. Still, tooth decay remains problematic, and one way to address it may be through the development of new mineralizing agents. Laboratory and clinical studies have demonstrated that the combination of fluoride and functionalized β-tricalcium phosphate (fTCP) produces stronger, more acid-resistant mineral relative to fluoride, native β-TCP, or fTCP alone. In contrast to other calcium-based approaches that seem to rely on high levels of calcium and phosphate to drive remineralization, fTCP is a low-dose system designed to fit within existing topical fluoride preparations. The functionalization of β-TCP with organic and/or inorganic molecules provides a barrier that prevents premature fluoride-calcium interactions and aids in mineralization when applied via common preparations and procedures. While additional clinical studies are warranted, supplementing with fTCP to enhance fluoride-based nucleation activity, with subsequent remineralization driven by dietary and salivary calcium and phosphate, appears to be a promising approach.

Biofunctional properties of caseinophosphopeptides in the oral cavity

Caseinophosphopeptides (CPPs), bioactive peptides released from caseins, have the ability to enhance bivalent mineral solubility. This is relevant to numerous biological functions in the oral cavity (promotion of tooth enamel remineralisation, prevention of demineralisation and buffering of plaque pH). Therefore, CPPs may play a positive role as prophylactic agents for caries, enamel erosion and regression of white spot lesions. Most in vitro and in situ studies demonstrate strong evidence for the bioactivity of CPPs in the oral cavity. Nevertheless, relatively little is known concerning their use as adjuvants for oral health and more particularly regarding their long-term effects on oral health.

In situ remineralization of white-spot enamel lesions by 500 and 1,100 ppm F dentifrices

The aim of this study was to evaluate the remineralization potential of three silica-containing NaF dentifrice systems in an intraoral model. Subjects (N = 30) in this randomized, three-phase, 28-day, crossover study served as their own control. Each participant wore a customized orthodontic appliance attached to a mandibular molar and contained one tooth block with caries-like lesion. For each phase, participants engaged in twice-daily brushing for 2 min with one of the following dentifrices: 500 ppm F, 500 ppm F plus functionalized β-tricalcium phosphate (fTCP), and a clinically proven 1,100 ppm F. After each phase, appliances were removed, and specimens were analyzed using surface microhardness (SMH), transverse microradiography (TMR), and cross-sectional microhardness (CSMH). Statistically significant (p < 0.05) remineralization of white-spot lesions relative to baseline occurred for each dentifrice as determined with SMH and TMR. No significant differences (p > 0.05) in SMH were found among the three groups, but trending revealed the 500 ppm F plus fTCP produced 26% and 27% greater SMH recovery relative to 500 and 1,100 ppm F, respectively. Similarly, no significant differences (p > 0.05) in TMR were found among the groups. However, the 500 ppm F plus fTCP dentifrice produced 10% and 38% greater mineral recovery relative to 500 and 1,100 ppm F, respectively, while reducing the lesion depth 30% and 52%, respectively. Significant differences (p < 0.05) in CSMH existed among the three dentifice groups at different enamel depths, but statistical differences (p < 0.05) in relative lesion size were only found between 500 ppm F plus fTCP and 500 ppm F. The combination of fTCP and fluoride in a single-compartment, water-based dentifrice can cooperate with fluoride to produce significant remineralization. These results suggest that the combination of 500 ppm F with fTCP may provide comparable anticaries benefits relative to a 1,100 ppm F dentifrice.

Strategies for noninvasive demineralized tissue repair

This article provides a state-of-the-art overview of clinically relevant evidence regarding effective, noninvasive management strategies to prevent, arrest, and remineralize caries lesions. With the rapidly increasing knowledge about oral biofilms and the process of caries in itself, the profession is embarking on new strategies. This is an exciting time, with several promising new agents and novel treatment modalities at the horizon to prevent and manage caries lesions. Some are already available in clinical practice. Studies, however, have yet to show conclusive evidence of clinical efficacy. None have shown to be more effective than fluoride and protection by sealant.