NMR studies of a novel calcium, phosphate and fluoride delivery vehicle-αS1-casein(59–79) by stabilized amorphous calcium fluoride phosphate nanocomplexes

Calcium phosphopeptides -- mechanisms of action and evidence for clinical efficacy

Phosphoproteins/phosphopeptides with clusters of acidic residues are found throughout nature, where they aid in the prevention of unwanted precipitation of solid calcium phosphates. The acidic residues, particularly phosphoserine, interact with calcium and stabilize clusters of calcium and phosphate. Saliva and milk are two examples of biological fluids that contain such phosphoprotein/phosphopeptide-stabilized calcium phosphates, and both share a similar evolutionary pathway. Saliva has been shown to have remineralization potential and is of critical importance in maintaining the mineral content of teeth in the oral environment. Milk can be enzymatically modified to release casein phosphopeptides that contain the clusters of residues that allow milk to stabilize high concentrations of calcium and phosphate. These casein phosphopeptide-stabilized amorphous calcium phosphate nanocomplexes (CPP-ACP) can stabilize even higher concentrations of calcium and phosphate than milk and can be considered a salivary biomimetic, since they share many similarities to statherin. The mechanisms of action and the growing body of scientific evidence that supports the use of CPP-ACP to augment fluoride in inhibiting demineralization and enhancing the remineralization of white-spot lesions are reviewed.

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.

Effects of casein phosphopeptide amorphous calcium fluoride phosphate paste on white spot lesions and dental plaque after orthodontic treatment: a 3-month follow-up

The effects of casein phosphopeptide amorphous calcium fluoride phosphate (CPP-ACFP) paste vs. control paste on the remineralization of white spot caries lesions and on plaque composition were tested in a double-blind prospective randomized clinical trial. Fifty-four orthodontic patients, with multiple white spot lesions observed upon the removal of fixed appliances, were followed up for 3 months. Subjects were included and randomly assigned to either CPP-ACFP paste or control paste, for use supplementary to their normal oral hygiene. Caries regression was assessed on quantitative light-induced fluorescence (QLF) images captured directly after debonding and 6 and 12 wk thereafter. The total counts and proportions of aciduric bacteria, Streptococcus mutans, and Lactobacillus spp. were measured in plaque samples obtained just before debonding, and 6 and 12 wk afterwards. A significant decrease in fluorescence loss was found with respect to baseline for both groups and no difference was found between groups. The size of the lesion area did not change significantly over time or between the groups. The percentages of aciduric bacteria and of S. mutans decreased from 47.4 to 38.1% and from 9.6 to 6.6%, respectively. No differences were found between groups. We observed no clinical advantage for use of the CPP-ACFP paste supplementary to normal oral hygiene over the time span of 12 wk.

Comparison of the remineralization potential of CPP-ACP and CPP-ACP with 900 ppm fluoride on eroded human enamel: An in situ study

OBJECTIVE

The aim of this in situ study was to compare the remineralization potential of pastes containing CPP-ACP and CPP-ACP with 900 ppm fluoride on human enamel softened by a cola drink.

DESIGN

Forty-five enamel specimens obtained from human third molar teeth were eroded in a cola drink for 8 min and then attached to intra-oral devices worn by five volunteers. The specimens were subjected to three different in situ remineralization protocols using: (1) CPP-ACP (Group I), (2) CPP-ACP with 900 ppm fluoride (Group II), and (3) saliva (Group III, control). Vickers microhardness measurements were obtained at baseline followed by demineralization and remineralization stages.

RESULTS

The CPP-ACP, CPP-ACP with 900 ppm fluoride and saliva controls resulted in 46.24%, 64.25% and 2.98% increase in post-erosion microhardness values, respectively. One-way ANOVA revealed statistically significant differences in the mean microhardness values between pastes containing CPP-ACP and CPP-ACP with 900 ppm fluoride.

CONCLUSIONS

Both CPP-ACP and CPP-ACP with 900 ppm fluoride substantially remineralized the softened enamel, with the CPP-ACP and fluoride combination showing higher remineralization potential than CPP-ACP. This study confirmed the synergistic effect of fluoride with CPP-ACP on remineralization of eroded enamel.

New Approaches to Enhanced Remineralization of Tooth Enamel

Dental caries is a highly prevalent diet-related disease and is a major public health problem. A goal of modern dentistry is to manage non-cavitated caries lesions non-invasively through remineralization in an attempt to prevent disease progression and improve aesthetics, strength, and function. Remineralization is defined as the process whereby calcium and phosphate ions are supplied from a source external to the tooth to promote ion deposition into crystal voids in demineralized enamel, to produce net mineral gain. Recently, a range of novel calcium-phosphate-based remineralization delivery systems has been developed for clinical application. These delivery systems include crystalline, unstabilized amorphous, or stabilized amorphous formulations of calcium phosphate. These systems are reviewed, and the technology with the most scientific evidence to support its clinical use is the remineralizing system utilizing casein phosphopeptides to stabilize and deliver bioavailable calcium, phosphate, and fluoride ions. The recent clinical evidence for this technology is presented and the mechanism of action discussed. Biomimetic approaches to stabilization of bioavailable calcium, phosphate, and fluoride ions and the localization of these ions to non-cavitated caries lesions for controlled remineralization show promise for the non-invasive management of dental caries.

The impact of window functions on NMR-based paramagnetic relaxation enhancement measurements in membrane proteins

Though challenging, solution NMR spectroscopy allows fundamental interrogation of the structure and dynamics of membrane proteins. One major technical hurdle in studies of helical membrane proteins by NMR is the difficulty of obtaining sufficient long range NOEs to determine tertiary structure. For this reason, long range distance information is sometimes sought through measurement of paramagnetic relaxation enhancements (PRE) of NMR nuclei as a function of distance from an introduced paramagnetic probe. Current PRE interpretation is based on the assumption of Lorentzian resonance lineshapes. However, in order to optimize spectral resolution, modern multidimensional NMR spectra are almost always subjected to resolution-enhancement, leading to distortions in the Lorentizian peak shape. Here it is shown that when PREs are derived using peak intensities (i.e., peak height) and linewidths from both real and simulated spectra that were produced using a wide range of apodization/window functions, that there is little variation in the distances determined (<1 A at the extremes). This indicates that the high degree of resolution enhancement required to obtain well-resolved spectra from helical membrane proteins is compatible with the use of PRE data as a source of distance restraints. While these conclusions are particularly important for helical membrane proteins, they are generally applicable to all PRE measurements made using resolution-enhanced data.

The effect of casein phosphopeptide-amorphous calcium phosphate and a cola soft drink on in vitro enamel hardness

BACKGROUND

The authors conducted an in vitro study to compare the hardness of normal enamel with enamel eroded by a cola soft drink and enamel remineralized by casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) or artificial saliva.

MATERIALS AND METHODS

The authors immersed 40 extracted sound central and lateral incisors alternately in a cola soft drink or artificial saliva for 10 cycles of five seconds each. They repeated this procedure two times at six-hour intervals. They divided the samples randomly into four groups and applied CPP-ACP to the samples, immersed them in artificial saliva, deionized water or both. They measured the hardness on the labial surface at baseline, after erosion and after remineralization and analyzed the data with one-way repeated-measures analysis of variance and two-way analysis of variance.

RESULTS

The cola soft drink significantly decreased enamel hardness. CPP-ACP and CPP-ACP and artificial saliva significantly increased the hardness of eroded enamel. CPP-ACP and CPP-ACP and artificial saliva increased the hardness of eroded enamel significantly more than artificial saliva did.

CONCLUSIONS

CPP-ACP increased the hardness of eroded enamel. CPP-ACP had a greater effect on enamel hardness than did artificial saliva.

CLINICAL IMPLICATIONS

Consumption of a cola soft drink can cause tooth erosion. CPP-ACP may significantly remineralize eroded enamel compared with artificial saliva.

Calcium phosphate-based remineralization systems: scientific evidence?

Dental caries remains a major public health problem in most communities even though the prevalence of disease has decreased since the introduction of fluorides. The focus in caries research has recently shifted to the development of methodologies for the detection of the early stages of caries lesions and the non-invasive treatment of these lesions. Topical fluoride ions, in the presence of calcium and phosphate ions, promote the formation of fluorapatite in tooth enamel by a process referred to as remineralization. The non-invasive treatment of early caries lesions by remineralization has the potential to be a major advance in the clinical management of the disease. However, for net remineralization to occur adequate levels of calcium and phosphate ions must be available and this process is normally calcium phosphate limited. In recent times three calcium phosphate-based remineralization systems have been developed and are now commercially available: a casein phosphopeptide stabilized amorphous calcium phosphate (Recaldent (CPP-ACP), CASRN691364-49-5), an unstabilized amorphous calcium phosphate (ACP or Enamelon) and a bioactive glass containing calcium sodium phosphosilicate (NovaMin). The purpose of this review was to determine the scientific evidence to support a role for these remineralization systems in the non-invasive treatment of early caries lesions. The review has revealed that there is evidence for an anticariogenic efficacy of the Enamelon technology for root caries and for the Recaldent technology in significantly slowing the progression of coronal caries and promoting the regression of lesions in randomized, controlled clinical trials. Hence the calcium phosphate-based remineralization technologies show promise as adjunctive treatments to fluoride therapy in the non-invasive management of early caries lesions.

Fluoride and casein phosphopeptide-amorphous calcium phosphate

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) slows the progression of caries and remineralizes enamel subsurface lesions. The aim of this study was to determine the ability of CPP-ACP to increase the incorporation of fluoride into plaque and to promote enamel remineralization in situ. Randomized, double-blind, cross-over studies involved mouthrinses and dentifrices containing CPP-ACP and fluoride. The mouthrinses were used for 60 sec, three times/day for 5 days, and supragingival plaque was collected and analyzed for F. The dentifrices were rinsed as a water slurry for 60 sec four times/day for 14 days in an in situ model. The addition of 2% CPP-ACP to the 450-ppm-F mouthrinse significantly increased the incorporation of fluoride into plaque. The dentifrice containing 2% CPP-ACP produced a level of remineralization similar to that achieved with a dentifrice containing 2800 ppm F. The dentifrice containing 2% CPP-ACP plus 1100 ppm F was superior to all other formulations.

In vitro synthesis and characterization of amorphous calcium phosphates with various Ca/P atomic ratios

Amorphous calcium phosphates (ACP) were synthesized utilizing poly(ethylene glycol) as stabilizing additive at low temperature. Effects of aging time, pH value, reactant and initial Ca/P atomic ratio on the phase and chemical composition of calcium phosphate precipitates were investigated by powder X-ray diffraction and induced coupled plasma atomic spectroscopy. It was found that ACP could be stabilized by poly(ethylene glycol) in the mother solution for more than 18 h at 5 degrees C, and Ca/P atomic ratios of ACP precipitates could be adjusted from 1.33 to 1.50 by controlling pH values and initial Ca/P atomic ratios. ACP precipitates were characterized by thermal gravity analysis, Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive spectrum. The results show that there is 4 wt% poly(ethylene glycol) in ACP powders without any contaminated ions, and the spherical particle size of ACP powders is 60 approximately 70 nm in the diameter with uniform size distribution which endows it as a potential precursor to prepare crystalline calcium phosphate phases. ACP has potential to be used as biodegradable and/or bioresorbable biomaterials and tissue engineering scaffold.