Breastfeeding and early childhood caries. Review of the literature, recommendations, and prevention.

CONTEXT: Early childhood caries is a chronic disease that affects a child's general state of health. The question of a link between primary tooth caries and breastfeeding has been addressed for many years, with contradictory results. The concomitant decay of primary teeth, effective establishment, or not, of oral hygiene, and alimentary diversification away from breastfeeding are all confounding factors in this topic. The aim of our study was to analyze the links between breastfeeding and the appearance of caries, as described in the scientific literature and in the recommendations of specialist societies. METHODS: A review of publications written in English and French was carried out, searching for the terms early childhood caries, decay and breastfeeding, focusing on literature reviews and meta-analyses dating from the past 10 years. The PubMed database of the US National Library of Medicine National Institutes of Health (NBCI) was used. Furthermore, a review of specialist dental and pediatric societies was conducted. RESULTS: Breastfeeding until the age of 1 year is not associated with an increased risk of dental caries, and may even provide protection compared with feeding with formula milk. By contrast, infants who are breastfed beyond the age of 12 months demonstrate an increased risk of caries. However, the results derive from heterogeneous studies that do not always take into account contradictory factors such as eating habits of the mother or infant (feeding during the night, number of meals per day, eating sweet foods etc.), dental hygiene, or the sociocultural context. Moreover, the most recent recommendations of pediatric and dental societies advise breastfeeding until the age of 2 years, suggesting that this be accompanied by toothbrushing and better nutrition by reducing the frequency and consumption of sugary foods, aimed at helping parents choose prolonged breastfeeding. CONCLUSION: Extended breastfeeding is a protective factor for childhood caries under 1 year of age. Beyond 1 year, it is difficult to conclude between protection and aggravation of caries because of the multiplicity of confounding factors such as dietary patterns, which vary depending on countries and families, and problems of oral hygiene. In practical terms, when breastfeeding continues beyond 1 year, consultation with a dentist is necessary for examination and preventive advice regarding dietary practices (especially sugar intake), oral hygiene, or supplementary fluoride.

Biocompatibility of blood tubings.

We studied hemocompatibility of various blood tubings with C3a anaphylatoxin measurement and comparative electron scanning microscopy. The following tubing materials were tested: polyvinylchloride (PVC) plasticised with phthalate (PVC), pvc plasticised with phthalate coextruded with polyurethane (PIV), and two phthalate-free lines: pvc plasticised with trimellitate coextruded with polyurethane (TRI) and pvc plasticised with LT 360 (LTP). Results of C3a generation rate showed a significant activation by all blood tubings, with a reduced rate with PIV when compared to all others. Electron scanning microscopy showed marked alterations of PIV surface on tubings stored for 6 months. Protein deposits on internal surfaces after dialysis were similar whatever tubing material was tested, but adhesive cell number was greater with TRI when compared to PVC and LTP. Hemocompatibility is unchanged with phthalate-free tubings when compared to phthalate plasticised ones. In contrast with phthalate plasticised PVC there is no beneficial effect of polyurethane coextrusion with trimellitate plasticised PVC in regard to C3a generation.

Blood lines should be considered in studies of biocompatibility during acetate haemodialysis.

In this one-year prospective study, the biocompatibility of blood lines used for acetate haemodialysis treatment was evaluated in 12 patients. These blood lines, polyvinyl chloride (PVC) and polyurethane extruded PVC (PE) respectively were compared in a schedule of four alternating three-month periods of treatment: PVC/PE/PVC/PE. White blood cell count, complement, IgE and thromboxane values were recorded monthly. A reduction in white blood cell and polymorphonuclear counts after 30 minutes of dialysis was significantly less during period 2 than period 1. Pre-dialysis eosinophil counts varied in a seasonally dependent pattern. We conclude that in spite of their small area, blood lines have some effect on biocompatibility and that the season of the year has to be considered in biocompatibility studies involving eosinophils.

Beta 2-microglobulin kinetics during haemodialysis and haemofiltration.

Since the identification of beta 2-microglobulin as a major component of 'dialysis amyloid', concern about its removal by different dialysis methods has been raised. Haemodialysis with regenerated cellulose membranes increases serum beta 2-microglobulin by 10-15%. Serial measurements show a very early increase during cuprophan haemodialysis, the mechanism of which is as yet unknown. After cuprophan haemodialysis, serum values return to the initial pretreatment concentrations by the time of the next haemodialysis. In contrast to regenerated cellulose, dialysis with polycarbonate lowers serum beta 2-microglobulin by 8%, and dialysis with polysulphone by 53%. As opposed to cuprophan, after polysulphone haemodialysis the serum concentrations have not returned to the initial pretreatment levels within 48 h. Comparison of beta 2-microglobulin removal using the same polysulphone membrane for haemodialysis and haemofiltration shows that beta 2-microglobulin is more effectively removed by convection than by diffusion when both treatment modes are matched for blood flow and urea clearance. Therefore, in contrast to haemodialysis with regenerated cellulose membranes, where a transient, intradialytic release of beta 2-microglobulin is induced, significant removal is observed using higher permeable membranes. These findings may have implications for the generation of 'dialysis amyloid'.

High-flux synthetic versus cellulosic membranes for beta 2-microglobulin removal during hemodialysis, hemodiafiltration and hemofiltration.

Efficient removal of beta 2 microglobulin (beta 2-M) in end-stage renal failure patients is a continuing preoccupation, as the incidence and severity of dialysis-associated amyloidosis are increasing. To evaluate comparative beta 2-M removal we studied six stable end-stage renal failure patients during high-flux 3-h haemodialysis, haemodia-filtration, and haemofiltration, using acrylonitrile, cellulose triacetate, polyamide and polysulphone capillary devices. The reduction of plasma beta 2-M, total removal in ultrafiltrate/dialysate, and beta 2-M sieving coefficients were measured by RIA. The results suggest that convection plays the major role in beta 2-M removal when high-flux synthetic membranes are used in combination with high blood flow rates. In contrast, using the cellulose triacetate membrane under investigation, beta 2-M removal is diminished when ultrafiltration rates are increased. Accordingly, in any future prospective study on the role of beta 2-M retention in the amyloidogenesis, it is recommended that high-flux synthetic membranes be employed rather than the type of high-flux cellulosic membranes used in this study. The modality with which these synthetic membranes are used is probably less important, as long as maximum convective transport rates are obtained. Under present conditions, this will imply haemofiltration or haemodiafiltration rather than haemodialysis.