Consensus report of the European Federation of Conservative Dentistry: erosive tooth wear--diagnosis and management.

OBJECTIVE: Due to an increased focus on erosive tooth wear (ETW), the European Federation of Conservative Dentistry (EFCD) considered ETW as a relevant topic for generating this consensus report. MATERIALS AND METHODS: This report is based on a compilation of the scientific literature, an expert conference, and the approval by the General Assembly of EFCD. RESULTS: ETW is a chemical-mechanical process resulting in a cumulative loss of hard dental tissue not caused by bacteria, and it is characterized by loss of the natural surface morphology and contour of the teeth. A suitable index for classification of ETW is the basic erosive wear examination (BEWE). Regarding the etiology, patient-related factors include the pre-disposition to erosion, reflux, vomiting, drinking and eating habits, as well as medications and dietary supplements. Nutritional factors relate to the composition of foods and beverages, e.g., with low pH and high buffer capacity (major risk factors), and calcium concentration (major protective factor). Occupational factors are exposition of workers to acidic liquids or vapors. Preventive management of ETW aims at reducing or stopping the progression of the lesions. Restorative management aims at reducing symptoms of pain and dentine hypersensitivity, or to restore esthetic and function, but it should only be used in conjunction with preventive strategies. CONCLUSIONS: Effective management of ETW includes screening for early signs of ETW and evaluating all etiological factors. CLINICAL RELEVANCE: ETW is a clinical condition, which calls for the increased attention of the dental community and is a challenge for the cooperation with other medical specialities.

Enamel erosion in dietary acids: inhibition by food proteins in vitro.

The aim of this study was to investigate the effects of two common food proteins on human enamel erosion in vitro. Erosion was measured by non-contact profilometry in citric, malic and lactic acids at pH 2.8, 3.2 and 3.8 and five commercially available soft drinks, in the presence of a salivary pellicle. Whole milk casein or hen egg ovalbumin was added to the acid solutions and drinks at 0.2% w/v, and the effect on erosion was determined by comparison with the corresponding solution without protein. Casein significantly reduced erosion in all but two solutions. The effects of the individual subfractions of casein in citric acid at pH 3.2 were similar to that of whole casein. Ovalbumin reduced erosion in some solutions, but the magnitude of the reduction was less than that with casein. A greater proportional reduction in erosion was seen in citric acid than in malic or lactic acids. We postulate that the mechanism involves adsorption of proteins to the pellicle or the enamel surface, forming a protein film with enhanced erosion-inhibiting properties. The citrate ion may play an active stabilising role, since erosion reduction was less in the other acids. In conclusion, casein and, to a lesser extent, ovalbumin show promise as potential anti-erosive additives to drinks.

In vitro studies on the effect of sodium tripolyphosphate on the interactions of stain and salivary protein with hydroxyapatite.

OBJECTIVES: To study properties of sodium tripolyphosphate (STP) relevant to inhibition or removal of dental stain in vitro. METHODS: The effects of STP and other phosphates on adsorption of a dietary chromogen (black tea polyphenol) and salivary protein to hydroxyapatite (HA) powder were studied by analysing loss of protein or tea stain from solutions mixed with HA or HA pre-treated with the test agents. The effects on desorption of protein and stain from HA were studied by analysis of water or solutions of test agents mixed with HA or HA pre-treated with saliva or tea solution. RESULTS: At concentrations and pH representative of those likely to occur in the mouth, STP inhibited adsorption of salivary protein and black tea polyphenol to, and desorbed these substances from, HA surfaces. Adsorption and desorption of protein and stain were not influenced by pH of the STP solutions but adsorption varied with concentration. STP showed equivalent effectiveness with respect to salivary protein adsorption and desorption as a longer-chain condensed phosphate. The inhibitory activity of HA-bound STP on adsorption of salivary protein and stain resisted extensive washing. CONCLUSIONS: STP is likely to be an effective agent for inhibiting and removing dental stain, whether bound directly to mineralised surfaces or indirectly via salivary pellicle.

Organic material and the optical properties of the dark zone in caries lesions of enamel.

Sections of uncavitated natural caries lesions of human enamel were extracted with various solvents and examined by polarizing microscopy. After lipid extraction, the dark zone enlarged by 19-162% and its birefringence increased, while after protein extraction it shrank by 37-92% and became less birefringent. It is concluded that occlusion of submicroscopic pores by organic material largely accounts for the optical properties of the dark zone. The results are not consistent with occlusion of pores by reprecipitation of mineral. On the basis of previous work, organic material in this location could influence demineralization and remineralization.

The hydroxyapatite ion activity product in acid solutions equilibrated with human enamel at 37 degrees C.

Five samples of powered enamel were each sequentially equilibrated 5 times at 37 degrees C with either 4 or 17 mmol/l H3PO4, in contact with air, and the ionic activity product for hydroxyapatite (IHA) estimated. There was evidence for preferential release of Mg and Na, especially in the first equilibrations. In two experiments, raised values of IHA were observed in the first equilibration but otherwise IHA was reasonable constant within experimental error and was much closer to the solubility product of hydroxyapatite than many previous estimates, mainly at 25 degrees C, suggest. The mean value of IHA for the majority fraction, averaged over all samples, was 1.7 (+/- 0.7) x 10(-58). Non-apatitic solids formed in all systems but solubility appeared nevertheless to be controlled by an apatitic phase: either the enamel mineral itself or apatite reprecipitated during the course of equilibration. High values of IHA reported previously may be due to use of conditions favouring dissolution only of more soluble factions or to metastability artifacts associated with control of solubility by non-apatitic phases.