Cost-effectiveness of probiotics and fluoride varnish in caries prevention in preschool children.

OBJECTIVES: The purpose of this study was to evaluate the cost-effectiveness of two preventive interventions aimed at increasing the proportion of caries-free preschool children of low socioeconomic status using a decision analytic model. METHODS: Two scenarios were tested, one with a school milk program (SMP) and one without (non-SMP). Fluoride varnish (FV) and a probiotic (PB) were compared to a do-nothing alternative among children in public nurseries/schools over a 4-year period. FV was applied biannually and a PB (Lactobacillus rhamnosus) added to milk powder prepared daily. A Markov decision tree model was utilized. Several sources of data were used to populate the model. Probabilistic and deterministic sensitivity analyses were performed, and a public provider perspective was used. RESULTS: In the SMP scenario, PB was more effective and less costly than FV and, compared with do-nothing, increased the proportion of caries-free children by 14.5%, with a cost of USD 12.5 per child (June 2018). PB presented an incremental cost-effectiveness ratio (ICER) or cost per extra caries-free child of USD 86.2. In the non-SMP scenario, both interventions were cost-effective. FV (compared with do-nothing) increased the percentage of caries-free children by 8.3% with an ICER of USD 338.3 and PB (compared with FV) increased the effect by 6.2% with an ICER of USD 1400.2. CONCLUSIONS: The findings showed that PB was most effective and less costly than FV in the SMP scenario only. This type of analysis and its results provide essential information for decision-makers to improve the oral health of preschool children.

Photo-Induced Partially Aromatized Intramolecular Charge Transfer.

Diverse models of intramolecular charge transfer (ICT) have been proposed for interpreting the origin of the charge-transfer (CT) state in donor-acceptor (D-A) dyes. However, a large variety of fused-heterocyclic dyes containing a pseudo-aromatic ring in the rigid structure have shown to be incompatible with them. To approximate a solution within the ICT concept, we reported a novel ICT model called partially aromatized intramolecular charge transfer (PAICT). PAICT involves the generation of a CT state from an ICT that occurred within a pre-excited D-A fused-heterocyclic structure possessing a pseudo-aromatic or unstable aromatic ring as the acceptor moiety. The model was proposed from the multiple-emissive mesomeric D-A N1-aryl-2-(trifluoromethyl)benzo[b][1,8]naphthyridin-4(1H)-one, whose excited mesomeric states, which are defined by the aromatic and pseudo-aromatic forms of the pyrindin-4(1H)-one ring, led to a common partial aromatized CT state upon excitation via PAICT. The latter was supported through theoretical calculations on the excited mesomeric states, one-dimensional (1D) and two-dimensional (2D) excitation-emission measurements in different solvents, and the detection of three excited states by lifetime measurements upon 370 nm excitation. The existence of mesomerism was supposed from: (i) two overlapping bands at 370-390 (or 400-420 nm) in UV-vis spectra, (ii) the direct interaction between the pyridinic nitrogen of one molecule and the carbonylic oxygen of the other found in the solid state and, (iii) the detection of three excited states by lifetime measurements. The PAICT opens new perspectives for interpreting the charge-transfer phenomenon in fused-heterocyclic dyes, in particular, those containing a pseudo-aromatic or unstable aromatic ring as an acceptor moiety.