Effect of casein and whey-protein solutions on caries experience and feeding patterns of the rat

Impact of Dairy Products and Plant-Based Alternatives on Dental Health: Food Matrix Effects

The impact of dairy products on dental health has been researched widely and shows an important role of various constituents, as well as the specific product matrix, in maintaining and improving dental health. These include, for instance, the position of lactose as the least cariogenic fermentable sugar, the high levels of calcium and phosphate, the presence of phosphopeptides as well as the antibacterial peptides lactoferrin and lysozyme and high buffering capacity. With plant-based alternatives for dairy products being developed and marketed these days, the specific benefits of dairy products in relation to dental health are often overlooked and most products contain more cariogenic carbohydrates, lack phosphopeptides, and have fewer minerals and less buffering capacity. Comparative studies performed to date indeed suggest that plant-based products do not match dairy counterparts when it comes to maintaining and improving dental health. Careful consideration of these aspects is required in relation to future developments of products and human diets. In this paper, we review the impact of dairy products and plant-based dairy alternatives on dental health.

Assessment of Cariogenicity by pH-value Decrement of Plaque Solution with Four Infant Milk Formulas: An In Vitro Study

Introduction

People all over the world use a wide variety of infant formulas to nourish the infants. Recent studies demonstrated the high caries-inducing potential of infant formulas. This indicates a need for awareness toward the possible role of the infant formulas in the etiology of early childhood caries (ECC).

Aim

The present study was undertaken to evaluate and comparatively assess the change in plaque pH solutions after fermenting four commonly used infant milk formulas.

Materials and methods

This simple randomized study was carried out on 40 healthy children aged 4–6 years old. The children received full-mouth prophylaxis before examination. They were asked not to implicate oral hygiene for 24 hours and not to have anything at least 2 hours prior the study. Supragingival plaque from the buccal surface of posterior teeth was collected using a Hu-Friedy's curette. Four commonly used infant milk formulas were prepared and given to children for rinsing. The pH of plaque samples were measured at 30 and 60 minutes at 37°C.

Results

The present study showed that all of the four infant milk formulas decreased the mean pH values in plaque solutions significantly after 30 and 60 minutes of preparation.

Conclusion

Our results showed that the plaque pH varied in response to the oral rinsing with the various infant formulas and most of infant formulas were able to reduce the pH significantly below the pH before the rinse. Based upon this study further evaluation of the cariogenicity of infant formulas is recommended.

How to cite this article

Pandey A, Pathivada L, Kajapuram P, et al. Assessment of Cariogenicity by pH-value Decrement of Plaque Solution with Four Infant Milk Formulas: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(3):263-266.

Fate of hydroxyapatite nanoparticles during dynamic in vitro gastrointestinal digestion: the impact of milk as a matrix

This study investigated the behavior of nano-sized particles of hydroxyapatite (nHA) during dynamic in vitro gastrointestinal digestion, alone or dispersed within skim milk. The dissolution and the structural changes of nHA were investigated by analyzing the dissolution of calcium and using transmission electron microscopy and X-ray diffraction. The dissolution of nHA during gastric digestion involved a rapid early stage and a much slower later stage. It was incomplete by the end of gastric digestion, both with and without milk. However, there was no sign of nHA recrystallization in the intestinal phase. X-ray diffraction analysis of digesta showed the breakdown of the crystalline structure of nHA and the formation of potentially new calcium phosphate phases during digestion. Skim milk formed a structural clot and significantly retarded the dissolution of nHA during gastric digestion. Possible mechanisms leading to the incomplete dissolution of nHA and the matrix effect of milk are discussed.

Evaluation of Plaque pH Changes Following Consumption of Health Drinks by Children: A Pilot Study

INTRODUCTION

With increased trend among people to choose a healthy diet, there is an increased consumption of health drinks by children. Thus, it is important to know their cariogenicity.

AIM

To evaluate the effect of consumption of health drinks viz., Horlicks, Boost and Complan on plaque pH in children.

MATERIALS AND METHODS

The study consisted of four groups: Group I (control)- 10% sucrose solution, Group II- Horlicks, Group III- Boost, Group IV- Complan. Samples of plaque from representative teeth were collected and pH was measured using an electrode outside the mouth. After baseline pH was recorded, children were given their respective drinks and were asked to consume slowly over a period of three to five minutes following swish with 20 ml of the test drink for one minute. The pH was then recorded after 10, 20, 30, 40 and 60 minutes of the post consumption period. Obtained values were subjected to one-way ANOVA test for multiple group comparison followed by Post-Hoc Tukey's test for group wise comparison.

RESULTS

Twenty minutes after consumption of Complan and Boost, pH was decreased, but not to the critical pH value as in case of sucrose. The pH was found to be slightly increased, 20 minutes post Horlicks consumption. Post 60 minutes consumption of all the drinks including sucrose solution, the pH was increased in comparison to post 20 minutes. However, 60 minutes post consumption of Boost and Horlicks, pH increased above the baseline.

CONCLUSION

Consumption of health drinks viz., Complan and Boost did not lower the plaque pH to the level of critical pH. Consumption of Horlicks increased the plaque pH.

Enamel remineralization assessment after treatment with three different remineralizing agents using surface microhardness: An in vitro study

AIM

The aim of this study is to evaluate the enamel remineralization after treatment with three different remineralizing agents using surface microhardness assessment.

MATERIALS AND METHODS

This in vitro study involves 50 enamel samples divided into five groups of 10 samples each. The positive control group consisted of intact enamel and a negative control group consisted of demineralized enamel samples. All groups excluding the positive control group were subjected to demineralization following which three of these groups were remineralized using remineralizing agents (casein phosphopeptide amorphous calcium phosphate [CPP-ACP] [GC tooth mousse], casein phosphopeptide amorphous calcium phosphate with fluoride [CPP-ACPF] [GC tooth mousse plus], sodium fluoride [phos-flur]). The groups treated with remineralizing agents were subjected to pH cycling over a period of 28 days. This was followed with assessment of surface microhardness (Micro Vickers Hardness tester, Matsuzawa Co., Ltd, Toshima, Japan).

STATISTICAL ANALYSIS

One-way analysis of variance test and posthoc Tukey test were conducted for multiple group comparison.

RESULTS

There was an improved enamel remineralization in the group, remineralized using CPP-ACPF in comparison with the other groups.

CONCLUSION

Casein phosphopeptide with fluoride is a promising material for remineralization of enamel subsurface lesions.

The effect of casein phosphopeptide amorphous calcium phosphate on the in vitro shear bond strength of orthodontic brackets

Objective

The purpose of this study was to evaluate the effect of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) on the shear bond strength (SBS) of brackets bonded to non-demineralized teeth with either phosphoric acid etching or self-etching primer.

Methods

Sixty human premolars were randomly assigned to 1 of 4 treatment groups (n = 15 each): phosphoric acid etching (group 1); self-etching primer (group 2); CPP-ACP for 2 weeks + phosphoric acid etching (group 3), and CPP-ACP for 2 weeks + self-etching primer (group 4). After bonding of the maxillary premolar metal brackets, specimens were subjected to shear forces in a testing machine. Scanning electron microscopy was used to observe etching patterns on the enamel surfaces of all teeth. A 2-way analysis of variance was used to test for effects of CPP-ACP and etching system on SBS.

Results

Significantly higher mean SBSs were observed in groups subjected to phosphoric acid etching (i.e., groups 1 and 3; p < 0.05). On the other hand, SBSs did not appear to be influenced by CPP-ACP (i.e., groups 3 and 4; p > 0.05). We observed a uniform and clear etched pattern on the enamel surface of the phosphoric acid etching groups.

Conclusions

CPP-ACP does not significantly affect the SBS of orthodontic brackets bonded to non-demineralized teeth, regardless of which adhesive method is used to bond the brackets.

Minimal intervention dentistry for managing dental caries - a review: report of a FDI task group

This publication describes the history of minimal intervention dentistry (MID) for managing dental caries and presents evidence for various carious lesion detection devices, for preventive measures, for restorative and non-restorative therapies as well as for repairing rather than replacing defective restorations. It is a follow-up to the FDI World Dental Federation publication on MID, of 2000. The dental profession currently is faced with an enormous task of how to manage the high burden of consequences of the caries process amongst the world population. If it is to manage carious lesion development and its progression, it should move away from the 'surgical' care approach and fully embrace the MID approach. The chance for MID to be successful is thought to be increased tremendously if dental caries is not considered an infectious but instead a behavioural disease with a bacterial component. Controlling the two main carious lesion development related behaviours, i.e. intake and frequency of fermentable sugars, to not more than five times daily and removing/disturbing dental plaque from all tooth surfaces using an effective fluoridated toothpaste twice daily, are the ingredients for reducing the burden of dental caries in many communities in the world. FDI's policy of reducing the need for restorative therapy by placing an even greater emphasis on caries prevention than is currently done, is therefore, worth pursuing.

Effect of chewing paneer and cheese on salivary acidogenicity: a comparative study

Aim: The aim was to evaluate the salivary pH reversal phenomenon by chewing paneer and processed cheese after a chocolate challenge.

Materials and methods: Thirty caries-free children were randomly selected and divided into 2 groups: Control group was given processed cheese (Amul) and the experimental group was given paneer (Amul) after a chocolate challenge. After determining the resting salivary pH using GC pH strips, the subjects were asked to eat the test foods and salivary pH was measured at time intervals of 5, 10, 15, 30 and 60 minutes to record the time taken for the salivary pH to return to baseline values after an acidogenic challenge.

Results: The data was analyzed and intergroup comparison was done using paired student’s t-test. The test meals increased salivary pH after chocolate challenge significantly from baseline values and neutralized the fall in pH after a chocolate challenge. The protective effect was evident after 5 minutes of consuming chocolate and was highest up to 30 minutes after which the salivary pH gradually fell but had not returned to baseline values even at 60 minutes.

Conclusion: The findings suggest that chewing of paneer like cheese abolishes the fall in salivary pH caused by sugar consumption and maybe recommended as a protective food in pediatric diet counseling.

How to cite this article: Tayab T, Rai K, Kumari V, Thomas E. Effect of Chewing Paneer and Cheese on Salivary Acidogenicity: A Comparative Study. Int J Clin Pediatr Dent 2012;5(1):20-24.

Clinical efficacy of casein derivatives: a systematic review of the literature

BACKGROUND

The objective of this article was to review systematically the clinical trials of casein derivatives (specifically casein phosphopeptide-amorphous calcium phosphate [CPP-ACP] complex) used in dentistry.

TYPES OF STUDIES REVIEWED

The authors included clinical studies that examined the efficacy of casein derivatives in dentistry. They excluded in vitro studies, case series, case reports, letters to editors (not containing primary data), editorials, review articles and commentaries, but read them to identify any potential studies.

RESULTS

The authors searched 98 articles for relevance, determined according to title, abstract and full text, resulting in a yield of 12 original studies. Nine were clinical trials that focused on caries prevention, seven of which showed that CPP-ACP (as found in sugar-free pellet or slab chewing gum, lozenges, milk or mouthrinse) was effective in preventing dental caries by remineralizing subsurface carious lesions in situ in a dose-response fashion. One was a clinical trial with conflicting results regarding the effect of CPP-ACP on the regression of white-spot lesions; one was a survey of the relief of dry-mouth symptoms; and one was an uncontrolled clinical study that showed the lack of effectiveness and lack of short-term therapeutic effect in treating dentin hypersensitivity.

CLINICAL IMPLICATIONS

The quantity and quality of clinical trial evidence are insufficient to make conclusions regarding the long-term effectiveness of casein derivatives, specifically CPP-ACP, in preventing caries in vivo and treating dentin hypersensitivity or dry mouth.

Effect of a CPP-ACP agent on the demineralization and remineralization of dentine in vitro

OBJECTIVES

The aim of this study was to determine in vitro the effect of a commercial paste based on CPP-ACP complex on the demineralization of sound human dentine and on remineralization potential of artificial caries-like lesions formed on dentine surfaces.

METHODS

Forty dentine specimens were prepared with hard tissue microtome. The specimens were divided in four groups the A, B, C and D (n=10). The specimen surfaces were subjected to surface analysis by Fourier transformance micro multiple internal reflectance infrared spectroscopy (micro MIR-FTIR). Tooth mousse was applied on surface specimens of A group, while no agent were applied on the specimens of B group. Afterwards, groups A, B, C and D were immersed in demineralization solution for 7 days. Afterwards, the surfaces were subjected to micro MIR-FTIR analysis and the mineral to matrix ratio was used to assess the extent of dentin demineralization (DM). Tooth mousse was applied on specimens of group C, while no agent was applied on specimens of group D. The groups C and D immersed in artificial saliva for 7 days and were subjected to analysis by micro MIR-FTIR and the mineral to matrix ratio was used to assess the extent of dentin remineralization (RM).

RESULTS

Group A showed significant lower %DM in comparison to group B. Group C resulted in a significant higher %RM compared to group D.

CONCLUSIONS

The presence of agent CPP-ACP on dentine surfaces provoked lower demineralization and higher remineralization in comparison with the dentine surfaces without agent.

The effect of different milk formulas on dental plaque pH

OBJECTIVES

The purposes of this study were (1) to investigate the effect of different milk formulas on dental plaque pH after rinsing with these three categories, type of protein-based formulas (milk-based, soy-based, protein hydrolysate), type of sugar (only lactose, lactose and other sugars, only non-milk extrinsic sugars), and casein ratio (high and low casein), and (2) to observe organic acids formed by different milk formulas.

METHODS

Baseline plaque pH and plaque pH at 2, 5, 10, 15, 20, 25, 30, and 60 min after rinsing with milk formulas were recorded by a combination electrode in 14 healthy subjects. Deionized water and 10% sucrose were used as a negative and positive control. The plaque sample was also analysed to identify and quantify the organic acids using a high-performance liquid chromatography. Parameters including minimum pH, maximum pH drop, and area under curve were compared by RMANOVA and paired t-test.

RESULTS

The minimum pH was not significantly different among different protein-based formulas, whereas, the maximum plaque pH drop of soy-based and milk-based formula was significantly higher than that produced by protein hydrolysate formula (P=0.022 and 0.03, respectively). Area under curve produced by soy-based and milk-based formulas was significantly larger than that created by protein hydrolysate formula (P=0.025 and<0.001, respectively). Milk formulas containing only lactose caused significantly less plaque pH change in minimum pH (P<0.001), maximum pH drop (P=0.003), and area under curve (P<0.001) when compared with formulas containing lactose and other sugar but not with special formulas containing only non-milk extrinsic sugar. Similarly, special formulas containing non-milk extrinsic sugar produced significantly lower minimum pH and smaller area under curve than formulas containing lactose and other sugar did (P=0.044 and 0.009, respectively). No different results were found between high and low casein follow-on formulas. Lactic acid was produced more by rinsing with formulas containing lactose and other sugars than that produced by formulas containing only lactose.

CONCLUSIONS

This study suggests that milk formulas containing added other sugars tend to cause a decrease in plaque pH.

In situ and non-invasive detection of specific bacterial species in oral biofilms using fluorescently labeled monoclonal antibodies

Noninvasive in situ detection of suspected cariogenic bacterial species within dental biofilms could facilitate monitoring of the dynamic change of oral microbial flora and assist in the assessment of the treatment efficacy of therapeutic agents. In this study, we explore the possibility to use three well-characterized monoclonal antibodies (MAbs) against Streptococcus mutans, Actinomyces naeslundii, and Lactobacillus casei to identify these three important members of the oral microbial community in the complex environment of oral biofilms. These MAbs, which were conjugated to different fluorescent labels and visualized with confocal laser scanning microscopy (CLSM), proved to be an useful tool to identify the three species of interest (S. mutans, A. naeslundii, and L. casei) under various experimental conditions including in vitro and in vivo derived oral biofilms. Manifold addition of the MAbs on consecutive days did not alter the biofilm structure thus allowing monitoring of the same biofilm over extended time periods. Using this MAb-based method the effect of sucrose challenge on the biofilm composition and the distribution of S. mutans, A. naeslundii, and L. casei were examined. S. mutans was found to be the predominant species under the various biofilm conditions tested. These studies indicate that MAbs based bacterial detection with CLSM is a versatile tool which permits new insights into the ecology of oral biofilm development.

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

The repair of early tooth enamel lesions has been recently demonstrated by tryptic phosphopeptides derived from milk caseins that associate with amorphous calcium phosphate (ACP) forming stable complexes. These casein phosphopeptides (CPP), containing the cluster sequence-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-, form calcium phosphate delivery vehicles that retard enamel demineralization and promote remineralization. Recently, we have shown that these peptides also stabilize calcium fluoride phosphate as soluble complexes. These complexes designated CPP-ACFP, have the potential to provide superior clinical efficacy in preventing dental caries and treating and repairing early stages of disease. In an approach to determine the ultrastructure of the casein phosphopeptide-amorphous calcium fluoride phosphate complexes, we have studied the structure of the predominant peptide alpha(S1)-CN(59-79) bound to ACFP using nuclear magnetic resonance (NMR) spectroscopy and X-ray diffraction. The alpha(S1)-CN(59-79) peptide stabilized calcium fluoride phosphate as amorphous nanocomplexes with a hydrodynamic radius of 2.12+/-0.26 nm. The nanocomplexes exhibited stoichiometry of one peptide to 15 calcium, nine phosphate and three fluoride ions. Sequence-specific resonance assignments were determined for the peptide alpha(S1)-CN(59-79) complexed to the ACFP. The secondary structure of the peptide alpha(S1)-CN(59-79) was characterized by sequential (i, i+1), medium-range (i, i+2) nOes and H alpha chemical shifts. The spectral data were compared with that of the peptide alpha(S1)-CN(59-79) bound to calcium ions, revealing that the structurally significant secondary NH and alpha-chemical shifts were similar.

Bioactive properties of milk proteins with particular focus on anticariogenesis

Beyond nutrition, there is an increasing amount of data and information to demonstrate a bioactive role for dairy components in adults including a role in prevention of dental caries. Specifically, the casein fraction and hydrolysates thereof have been the focus of researchers investigating cariogenicity prevention. Tooth enamel is a polymeric substance consisting of crystalline calcium phosphate embedded in a protein matrix. Dental caries develop by acidic demineralization (calcium and phosphorus solubilization) of tooth enamel. Demineralization occurs directly (acidic food consumption) or indirectly (by fermentation products of dental plaque odontopathogenic bacteria growing on residual food particles between teeth or adhering to the plaque). Research efforts with milk derived bioactive peptides have focused on inhibition of cariogenic, plaque-forming bacteria, inhibition of tooth enamel demineralization, and subsequent enamel remineralization. Caseinophosphopeptides (CPP) and glycomacropeptide (GMP) have been patented for use in common personal hygiene products to prevent dental caries. Research has shown CPP and GMP to be growth inhibitory to the cariogenic bacteria Streptococcus mutans and other species. Additionally, CPP forms nanoclusters with amorphous calcium phosphate (AMP) at the tooth surface to provide a reservoir of calcium and phosphate ions to maintain a state of super saturation with respect to tooth enamel. This would buffer plaque pH, and also provide ions for tooth enamel remineralization. Glycosidic structures attached to GMP are important to numerous bioactive properties of the peptide including anticariogenicity. Like CPP, GMP has shown inhibitory activity to enamel demineralization and promotes tooth enamel remineralization.

Immunization with the RgpA-Kgp proteinase-adhesin complexes of Porphyromonas gingivalis protects against periodontal bone loss in the rat periodontitis model

A major virulence factor of Porphyromonas gingivalis is the extracellular noncovalently associated complexes of Arg-X- and Lys-X-specific cysteine proteinases and adhesins designated the RgpA-Kgp complexes. In this study we investigated the ability of RgpA-Kgp as an immunogen to protect against P. gingivalis-induced periodontal bone loss in the rat. Specific-pathogen-free Sprague-Dawley rats were immunized with either formalin-killed whole P. gingivalis ATCC 33277 cells with incomplete Freund's adjuvant, RgpA-Kgp with incomplete Freund's adjuvant, or incomplete Freund's adjuvant alone. The animals were then challenged by oral inoculation with live P. gingivalis ATCC 33277 cells. Marked periodontal bone loss was observed in animals immunized with incomplete Freund's adjuvant alone; this bone loss was significantly (P < 0.05) greater than that detected in animals immunized with formalin-killed whole cells or RgpA-Kgp or in unchallenged animals. There was no significant difference in periodontal bone loss between animals immunized with formalin-killed whole cells and those immunized with RgpA-Kgp. The bone loss in these animals was also not significantly different from that in unchallenged animals. DNA probe analysis of subgingival plaque samples showed that 100% of the animals immunized with incomplete Freund's adjuvant alone and challenged with P. gingivalis ATCC 33277 were positive for the bacterium. However, P. gingivalis ATCC 33277 could not be detected in subgingival plaque samples from animals immunized with formalin-killed whole cells or with RgpA-Kgp. Immunization with formalin-killed whole cells or RgpA-Kgp induced a high-titer serum immunoglobulin G2a response. Western blot analysis of RgpA-Kgp using pooled protective antisera taken from rats immunized with RgpA-Kgp revealed immunodominant bands at 44, 39, and 27 kDa. In conclusion, immunization with RgpA-Kgp restricted colonization by P. gingivalis and periodontal bone loss in the rat.

Dental caries-protective agents in milk and milk products: investigations in vitro

OBJECTIVES

To characterise and identify the anti-dental caries components that exist in milk and milk products.

METHODS

Standard enamel or hydroxyapatite demineralisation tests were devised to simulate the action of acid on tooth mineral, and they were used to show which constituents of milk possessed a potential protective action against acid attack.

RESULTS

Milk and milk products were fractionated and tested, revealing that minerals, including calcium and phosphorus, played a part in this protective process. The findings also drew attention to the effectiveness of minor milk protein or protein-associated components, the structures of which are mostly known, which were separated and characterised by gel electrophoresis as proteose-peptone fractions 3 and 5. The strength of adsorption of the protein or polypeptides in these fractions to dental enamel was measured and found to be sufficient to reduce the extent of demineralisation of enamel by acid buffer solutions.

CONCLUSIONS

The removal of lactose, fat, casein and other proteins had little influence on the protective effect of the milk fractions. Besides calcium and phosphorus, milk contains other more powerful protective factors, which were identified as proteose-peptone fractions 3 and 5. Details of their composition and the strength of their adherence to the surface of dental mineral are given.

Biological mechanisms of early childhood caries

The present paper reviews biological issues in early childhood caries (ECC) in light of the current understanding of the field. Despite the general global decline in dental caries in the past decades, ECC has become a significant problem in many developing countries and some minority communities in western industrialized nations. Like other types of caries, ECC is caused by mutans streptococci that ferment dietary carbohydrates to produce acid attacks on susceptible teeth over a period of time. However, while the general etiology of ECC appears similar to that of other types of caries, the predisposing factors are still unclear. The biology of ECC may be modified by several factors unique to young children, related to the implantation of cariogenic bacteria, immaturity of the host defense systems, as well as behavioral patterns associated with feeding and oral hygiene in early childhood.

Anticariogenic complexes of amorphous calcium phosphate stabilized by casein phosphopeptides: a review

Using laboratory, animal, and human in situ caries models, investigators have shown that casein phosphopeptide amorphous calcium phosphate complexes (CPP-ACP) exhibit an anticariogenic activity. The casein phosphopeptides (CPP) are produced from a tryptic digest of the milk protein casein by aggregation with calcium phosphate and purification by ultrafiltration. The CPP have a remarkable ability to stabilize calcium phosphate in solution and substantially increase the level of calcium phosphate in dental plaque. Through their multiple phosphoseryl residues, the CPP bind to forming clusters of amorphous calcium phosphate (ACP) in metastable solution, preventing their growth to the critical size required for nucleation and precipitation. The proposed mechanism of anticariogenicity for the CPP-ACP is that they localize ACP in dental plaque, which buffers the free calcium and phosphate lon activities, thereby helping to maintain a state of supersaturation with respect to tooth enamel depressing demineralization and enhancing remineralization. The CPP-ACP, unlike fluoride, can be added to sugar-containing foods and therefore have commercial potential as an additive to foods as well as to toothpastes and mouthwashes for the control of dental caries.

The effect of milk and sucrose consumption on caries in 6-to-11-year-old Italian schoolchildren

The effect of milk on dental caries was studied on a sample of 6-to-11-year-old Italian schoolchildren. The daily amount of milk consumed and the frequency of consumption of sucrose-containing foods were obtained by a 24-hour dietary diary. In the subsequent oral examination, the level of visible plaque and the number of decayed, extracted and filled teeth (both primary and permanent) of the children were recorded. 439 children (217 boys) who did not use fluoride prophylaxis and with poor oral hygiene were selected from among 890 children. They were divided into three groups according to the frequency of sucrose consumption. The data were statistically analysed using multiple logistic regression. The children consumed a daily average of 209 +/- 133 ml of milk and there were no differences among the three groups in this respect. As expected, the dental health of the children with low sucrose frequency was significantly better than that of the children with high sucrose frequency. The regression on the whole sample showed a weak, significant, negative association between milk consumption and caries (p < 0.05). In the group of high sucrose-consuming children a negative, highly significant association was found (p < 0.001), while in the two groups of low and moderate sucrose-consuming children no association was found. These data suggest that, in the present sample of children who did not use fluoride and with poor oral hygiene, milk has a caries preventive effect only on those subjects with a high daily sucrose-consuming frequency.

Incorporation of caseinoglycomacropeptide and caseinophosphopeptide into the salivary pellicle inhibits adherence of mutans streptococci

The protective effects of milk and milk products against dental caries have been demonstrated in many animal studies. We have shown that this effect was mediated by micellar casein or caseinopeptide derivatives. A reduction in the Streptococcus sobrinus population in the oral microbiota of animals fed diets supplemented with these milk components was consistently observed. A possible explanation for these findings is that milk components are incorporated into the salivary pellicle, thereby reducing the adherence of S. sobrinus. This hypothesis was tested in vitro by the incubation of bovine enamel discs with unstimulated saliva. The resulting pellicle was washed and incubated with caseinoglycomacropeptide (CGMP) and/or caseinophosphopeptide (CPP) labeled with 17- and 12-nm gold particles. All samples were prepared for electron microscopy by high-pressure freezing followed by freeze-substitution. It was demonstrated by high-resolution scanning electron microscopy with back-scattered electron imaging, as well as by transmission electron microscopy, that both peptides were incorporated into the pellicle in exchange for albumin, confirming previous findings. This protein was identified with a mouse anti-human serum albumin followed by goat anti-mouse IgG labeled with 25-nm gold particles. Incorporation of CGMP and/or CPP into salivary pellicles reduced the adherence of both S. sobrinus and S. mutans significantly. It is suggested that the calcium and phosphate-rich micellar casein or caseinopeptides are incorporated into the pellicle. The resulting ecological shifts, together with the increased remineralization potential of this biofilm, may explain its modified cariogenic potential.

Anticariogenicity of calcium phosphate complexes of tryptic casein phosphopeptides in the rat

Casein phosphopeptides (CPP) stabilize calcium phosphate through the formation of casein-phosphopeptide amorphous calcium-phosphate complexes (CPP-CP). The ability of CPP-CP to reduce caries activity was investigated by use of specific-pathogen-free rats inoculated with Streptococcus sobrinus. The animals consumed a defined cariogenic diet free of dairy products. Solutions (100 microL) of the CPP-CP (0.1, 0.2, 0.5, 1.0% w/v) were applied to the animals' molar teeth twice daily. Other groups of animals received solutions containing 500 ppm F, the non-phosphorylated peptides of a casein tryptic digest (0.5% w/v), or the calcium-phosphate complex of a synthetic octapeptide, Ac-Glu-Ser(P)-Ile-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-NHMe, corresponding to the common sequence in the CPP. The CPP-CP significantly reduced caries activity in a dose-response fashion, with 1.0% CPP-CP producing 55% and 46% reductions in smooth surface and fissure caries activity, respectively, being similar to that of 500 ppm F. The anticariogenic effects of CPP-CP and fluoride were additive, since animals receiving 0.5% CPP-CP plus 500 ppm F had significantly lower caries activity than those animals receiving either CPP-CP or fluoride alone. The tryptic digest of casein with the phosphopeptides selectively removed showed no anticariogenic activity. The synthetic octapeptide-calcium phosphate complex significantly reduced caries activity, confirming that this calcium-phosphate-stabilizing portion of the casein phospho-peptides is associated with anticariogenicity. The CPP-CP did not significantly affect the level of S. sobrinus in fissure plaque.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of milk and casein proteins on the adherence of Streptococcus mutans to saliva-coated hydroxyapatite

Experiments sought to determine the nature of the binding of milk proteins to hydroxyapatite (HA) and to saliva-coated hydroxyapatite (sHA), and to determine the effect of milk and casein on the adherence of Streptococcus mutans GS-5 to sHA. The binding of radiolabelled alpha-casein to HA was reduced when incubated simultaneously with parotid saliva, and enhanced in the presence of milk. The binding of beta- and kappa-casein to HA was unaffected by the presence of parotid saliva and enhanced by the presence of milk. The in vitro bacterial adherence of Strep. mutans GS-5 to sHA beads was reduced when beads were coated with milk instead of buffer, or when bacteria were added to sHA in the presence of milk instead of buffer. Casein proteins (alpha, beta, kappa) added to sHA simultaneously with bacteria inhibited the adherence of Strep. mutans GS-5 to sHA. kappa-Casein, when bound to sHA, inhibited streptococcal adherence to sHA; alpha- and beta-casein, when bound to sHA, had no effect on streptococcal adherence. Fractionation of kappa-casein by anion-exchange chromatography revealed the anti-adherence activity of kappa-casein was mediated primarily by a 40,000 mol. wt. glycoprotein-containing fraction. These data show that milk, particularly kappa-casein fractions, can modulate the adherence of Strep. mutans GS-5 to SHA surfaces in vitro.

In vitro modulation of oral bacterial adhesion to saliva-coated hydroxyapatite beads by milk casein derivatives

Bovine caseinate, derivatives of its glycosylated moiety [caseinoglycomacropeptide (CGP)], and caseinophosphopeptides were evaluated as inhibitors of adhesion of oral bacteria to saliva-coated hydroxyapatite beads (S-HA). All milk casein-derived components behaved as potent inhibitors of Streptococcus sanguis OMZ 9 and Streptococcus sobrinus OMZ 176 adhesion to S-HA, whereas neither bovine serum albumin nor polyethyleneglycol were able to interfere with the adhesion of these strains. By contrast, none of the molecular species tested was able to inhibit the attachment of Actinomyces viscosus Ny 1 to S-HA. On the other hand, casein derivatives were shown to displace human serum albumin from S-HA beads. They were also able to bind to the bacterial cell surface of all strains examined. Collectively, these findings suggest that interactions between acidic casein-derived milk components and the biological surfaces involved in bacterial adhesion to S-HA result in an inhibitory effect that is selective for the oral streptococci examined.

The use of milk as a saliva substitute

Xerostomia, a clinical manifestation of salivary gland dysfunction, affects many people. These individuals frequently sip liquids to alleviate the discomforts associated with hyposalivation. Milk appears to have many of the chemical and physical properties of a good saliva substitute. Besides the obvious benefit of providing moisture and lubrication for the dehydrated mucosa, milk buffers oral acids, reduces enamel solubility, and contributes to enamel remineralization. These anticariogenic factors are generally attributed to the high calcium and phosphate content along with the milk phosphoproteins that strongly adsorb to enamel. Patients with xerostomia frequently have difficulty in obtaining proper nutrition due to problems associated with lubricating, masticating, tasting, and swallowing food. Milk is a food with high nutritional quality that would certainly benefit most patients with xerostomia. Because of the nutritional, anticariogenic, and moisturizing properties of milk, patients with xerostomia may find milk of value as a saliva substitute to help reduce the oral health problems associated with hyposalivation.

The effect of cheese on dental caries: a review of the literature

The relationship between nutrition and dental health has been a topic of interest for many years. Recently, the cariostatic properties of cheese have been the subject of intensive research. Most of these studies suggest that the use of cheese as the final food in a meal will help to reduce caries. Several mechanisms by which cheese may reduce enamel demineralization have been proposed. Chewing cheese stimulates saliva flow. The alkaline nature of saliva buffers the acids formed in plaque. There is also an increased rate of sugar clearance due to the diluting action of cheese-stimulated saliva. Research has also suggested that chewing cheese may reduce the levels of cariogenic bacteria. This may be secondary to the reduced incidence of caries as conditions within a carious lesion tend to promote the growth of these organisms. The high calcium and phosphorus content seems to be another factor in the cariostatic mechanism of cheese. Both casein and whey protein seem to be involved in the reduction of enamel demineralization. Casein phosphopeptides may also be responsible for some anticariogenicity by concentrating calcium and phosphate in plaque. An overview of the effect of milk on dental caries is also presented in this review.

Protein dissimilation by human salivary-sediment bacteria

Proteins of known composition and structural characteristics were incubated (1.0 mg/mL) with re-suspended salivary sediment (2.5% v/v) in a lactate-salt medium with an initial pH of 5.2 for two hr at 37 degrees C. Hydrolysis of the proteins was monitored by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Hydrogen ion, amines, and ammonia were measured by use of a combined pH electrode, high-performance liquid chromatography, and glutamate dehydrogenase, respectively. Of the proteins studied, the caseins alpha s1, beta, and kappa and the histones H1 and H3 were extensively hydrolyzed by the salivary-sediment bacteria. The hydrolysis of these proteins was attributed to their relative lack of tertiary (folded) structure. The only amine detected was the polyamine putrescine arising from the catabolism of arginine following the hydrolysis of the arginine-rich histone H3. None of the other proteins extensively hydrolyzed by salivary sediment, although containing arginyl and lysyl residues, served as substrates for putrescine or cadaverine production. Pre-hydrolysis of the arginine-rich histone H3 and poly-L-arginine with trypsin resulted in a marked increase in putrescine produced, suggesting that the salivary-sediment proteolytic activity was not "trypsin-like". Incubation of salivary-sediment bacteria with the caseins and the histone H3 resulted in an increase in ammonium ion concentration and an associated decrease in hydrogen ion concentration. The increase in ammonium ion concentration not attributed to arginine hydrolysis was correlated with the content of glutaminyl plus asparaginyl residues of the proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Colonization of rat molar teeth by mutans streptococci with different salivary agglutination characteristics

The oral implantation of salivary agglutination-positive and -negative mutans streptococci was studied using streptomycin resistant (StrR) organisms. StrR Streptococcus mutans strains Ingbritt and NCTC 10449 are agglutinated by rat saliva and the StrR strains Streptococcus sobrinus 6715-13 and Strep. mutans GS5 are not. Four groups of Sprague-Dawley rats were inoculated orally with each organism (one per group) and fed a sucrose diet. A further two groups of animals were similarly inoculated with either the agglutination-positive Strep. mutans Ingbritt or the agglutination-negative Strep. sobrinus 6715-13 and fed a glucose diet. StrR streptococci were recovered from smooth-surface dental plaque of all animals on the sucrose diet with no significant difference in the recovery of agglutination-positive Strep. mutans strains Ingbritt and NCTC 10449 and agglutination-negative Strep. mutans GS5. However, the recovery of agglutination-negative Strep. sobrinus 6715-13 from smooth-surface plaque of animals on either the sucrose or the glucose diets was significantly lower than that of the other strains. Agglutination-positive Strep. mutans Ingbritt colonized smooth enamel surfaces of animals on the sucrose and the glucose diets in numbers that were not significantly different. However, the colonization of such surfaces by agglutination-negative Strep. sobrinus 6715-13 was significantly enhanced by the sucrose diet. Agglutination-positive and -negative StrR mutans streptococci were recovered from fissure plaque of all inoculated sucrose-fed animals in numbers that were not significantly different. Successful colonization of smooth enamel surfaces by the StrR streptococci resulted in increased smooth-surface caries.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cheese extract and its fractions on enamel demineralization in vitro and in vivo in humans

In order to isolate and identify the most active anti-cariogenic components(s) of aqueous cheese extract (CE), we separated it into low (LMW) (MW less than 500), medium (MMW) (500 less than MW less than 10,000), and high (HMW) (MW greater than 10,000) molecular weight fractions by means of the Amicon ultrafiltration system. These fractions were then tested in vitro with a bacterial system containing S. mutans, adapted from that of Turtola (1977). The LMW fraction reduced the demineralization caused by the fermentation of sucrose by 96% (p less than 0.001) as compared with the water control; this was not significantly different from a 50% concentration of the CE. The MMW and HMW fractions reduced demineralization by 36 and 42%, respectively. The concentrations of acid-soluble calcium and phosphorus in CE, LMW, MMW, and HMW were 1509 and 462, 991 and 310, 231 and 7, and 162 and 3 micrograms/mL, respectively. A solution containing the same levels of calcium and phosphorus as CE was somewhat more effective in reducing demineralization in vitro than was CE itself (p less than 0.01). In vivo, the addition of these same calcium and phosphorus levels to a 10% sucrose solution reduced its cariogenicity by 67% (p less than 0.001), as judged by the intra-oral cariogenicity test (ICT). Plaque calcium and phosphorus concentrations were significantly higher in the ICT plaque samples subjected to the sucrose-Ca,P solution (p less than 0.01) than in the sucrose control. The resting pH, minimum pH, and shape of the pH curves produced by the sucrose control and sucrose-Ca,P were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

The prevention of sub-surface demineralization of bovine enamel and change in plaque composition by casein in an intra-oral model

The ability of bovine milk phosphoprotein (casein) to be incorporated into plaque, prevent enamel sub-surface demineralization, and affect bacterial composition was determined using a modified intra-oral caries model. The intra-oral model consisted of a removable appliance containing a left and right pair of bovine enamel slabs placed to simulate an approximal area. Supragingival plaque was collected and impacted into the left and right inter-enamel spaces. The left side of the appliance was exposed to various sugar and salt solutions, while the right side was exposed to sugar and casein solutions. Sodium caseinate, the major fraction alpha s1-casein, and a tryptic digest of alpha s1-casein (TD-casein) were studied. Sodium caseinate at a level of 2% w/v in a 3% sucrose-3% glucose-salt solution (pH 7.0) prevented sub-surface enamel demineralization over a ten-day period as shown by microradiography and microhardness. Two exposures of a 2% w/v sodium caseinate, alpha s1-casein, or TD-casein solution (pH 7.0) per day prevented sub-surface enamel demineralization caused by six exposures of a 3% sucrose-3% glucose-salt solution per day over a ten-day period. Intact alpha s1-casein and tryptic peptides were shown immunochemically to be incorporated into the inter-enamel plaque. The incorporation of casein and its breakdown in plaque did not produce a significant change in the amount or composition of plaque bacteria. The ability of casein and tryptic peptides to prevent enamel demineralization was related to their incorporation into plaque, thereby increasing plaque calcium phosphate and acid-buffering capacity by the phosphoseryl, histidyl, glutamyl, and aspartyl residues and indirectly through catabolism by plaque bacteria.

Characterization of a rat salivary sialoglycoprotein complex which agglutinates Streptococcus mutans

Rat saliva agglutinated Streptococcus mutans Ingbritt and NCTC 10449 and Streptococcus sanguis NCTC 7864 but not S. mutans NCTC 10921, GS 5, or LM 7, Streptococcus sobrinus 6715-13 or OMZ 65, or Streptococcus cricetus HS 6, as measured turbidometrically. The specificity of agglutination by rat saliva was the same as that by human saliva. Agglutination was associated with a mucin complex (rat salivary agglutinin complex [rS-A]) of sulfated sialoglycoproteins, with a trace of associated lipid and an apparent Mr of 1.6 X 10(6), isolated by gel-filtration Fast Protein Liquid Chromatography. The complex was dissociated in a high-ionic-strength buffer containing 6 M urea and then fractionated by gel filtration and anion-exchange Fast Protein Liquid Chromatography into four sulfated sialoglycoprotein components, designated rS-A-1Q1, rS-A-1Q2, rS-A-1Q3, and rS-A-2, with rS-A-1Q2 being polydisperse through differential glycosylation of the polypeptide backbone. The dissociation destroyed agglutination activity. The polypeptide backbones contained up to 42% serine plus threonine and up to 40% glycine plus alanine plus proline plus valine. The carbohydrate moiety of the rS-A sialoglycoproteins consisted of N-acetylgalactosamine, sialate, galactose, fucose, N-acetylglucosamine, and small amounts of mannose, with the predominant sugar being N-acetylgalactosamine. Agglutination was inhibited by 1 mM EDTA but was restored by 1.5 mM CaCl2. Agglutination was also inhibited by 5 mM CaCl2; nonimmune sera; cationic polymers; and wheat germ, lentil, soybean, and peanut lectins. However, agglutination was not affected by lipoteichoic acid, various anionic proteins, or various sugars. Neuraminidase treatment of rS-A did not affect activity, but tryptic digestion of S. mutans did prevent agglutination. The results are consistent with calcium bridging the negative groups within the rS-A complex and allowing the approach of rS-A to the bacterial cell surface to effect a specific conformational attachment.