Comparative tooth whitening efficacy of 18% carbamide peroxide liquid whitening gel using three different regimens

OBJECTIVE: Recently, a novel paint-on liquid whitening gel--Colgate Simply White Clear Whitening Gel--which contains 18% carbamide peroxide, has been developed as a self-administered tooth bleaching system. The purpose of the present study was to determine the efficacy and safety of this product using alternate exaggerated or simplified treatment regimens. METHODOLOGY: This was a three-week clinical trial using a parallel, double-blind, stratified protocol with three different instructions for application: 1) twice-daily, no air-drying, and 15 minutes without eating/drinking; 2) three times daily, 30-second air-drying and 30 minutes without eating/drinking; or 3) four times daily, 30-second air-drying and 30 minutes without eating/drinking. One-hundred and twenty (120) healthy volunteers were balanced into three equal groups based on shade scores (A3 or darker). Clinical evaluations (shade guide, oral tissue health, gingival index and visual analog sensitivity score) were performed on each group at baseline and weekly for the next 21 days. At the conclusion of the study, a survey of the subjects' opinions on their assigned product regimen was also conducted. RESULTS: Subjects who used Colgate Simply White Clear Whitening Gel three and four times daily achieved the greatest shade improvement (5.88 +/- 1.53 shades, and 5.57 +/- 1.54, respectively). However, these values were only about one shade better than the value observed for the more convenient, twice-daily, "no-dry" regimen (4.51 +/- 1.77 shades), though they were statistically significant (p < 0.05). The result for the four-times daily protocol was not statistically different from the three-times group. Also, no differences were observed between the groups concerning oral tissue health, gingival index or tooth sensitivity, and no adverse effects were observed or reported regardless of the regimen used. Surveys completed by the subjects showed that those who used the twice-daily, "no-dry" regimen found the product to be the easiest to use, the most comfortable and the most pleasant tasting. CONCLUSION: It can be concluded from the clinical data that three or four applications of Colgate Simply White Clear Whitening Gel per day provided better efficacy. In addition, the use of the whitening gel twice daily, even without "dry time" and only 15 minutes without eating/drinking, yielded results that were comparable to previously reported results using the original on-label directions. The potential additional benefit to the "simplified regimen" is that it was perceived to be the most convenient and comfortable. The use of Colgate Simply White Clear Whitening Gel up to four times daily for up to three weeks is also safe, and the tendency of abusing the product with more frequent daily use may be deterred by the inconvenience reported by the study subjects.     

Drosophila lifespan enhancement by exogenous bacteria

We researched the lifespan of Drosophila under axenic conditions compared with customary procedure. The experiments revealed that the presence of bacteria during the first week of adult life can enhance lifespan, despite unchanged food intake. Later in life, the presence of bacteria can reduce lifespan. Certain long-lived mutants react in different ways, indicating an interplay between bacteria and longevity-enhancing genes.     

Insight in early psychosis: a 1-year follow-up

Insight was investigated in 180 individuals consecutively admitted to a comprehensive early psychosis treatment program. Insight was assessed on admission and after 3, 6 and 12 months. Insight improved significantly over 12 months, and was negatively correlated with both positive and negative symptoms, and positively correlated with depressive symptoms at admission. There were no associations with cognition.     

L-CCG-I activates group III metabotropic glutamate receptors in the hippocampal CA3 region

Specific agonists of metabotropic glutamate receptors (mGluRs) provide powerful tools to discriminate afferent fibers originating from different presynaptic neurons. The group II mGluR agonists L-CCG-I ((2S,1'S,2'S)-2-(2-carboxycyclopropyl)glycine) and DCG-IV ((2S,2'R,3'R)-2-(2',3'-dicarboxy-cyclopropyl)glycine) are commonly used to distinguish between mossy fiber and associational-commissural (A/C) fiber input to the hippocampal CA3 region because only on the former group II mGluRs are expressed. Since previous reports indicated that L-CCG-I can activate group III mGluRs as well, we investigated whether L-CCG-I depresses A/C field potentials. L-CCG-I (10-300 microM) exhibited a significant dose-dependent and reversible reduction of A/C field potentials by 8 +/- 4% (10 microM), by 32 +/- 4% (100 microM, p < 0.001) and by 38 +/- 7% (300 microM, p < 0.05) that was accompanied by a concomitant increase in paired-pulse facilitation. Moreover, the selective group III antagonist (R,S)-alpha-methylserine-O-phosphate (MSOP; 100 microM) significantly reduced the field potential inhibition by L-CCG-I (100 microM) to 9 +/- 4% (p < 0.05). In contrast, DCG-IV did not affect A/C field potentials. In conclusion, the purported group II mGluR agonist L-CCG-I depresses A/C synaptic transmission by activation of group III mGluRs. For this reason, DCG-IV should be the drug of choice when aiming to discriminate between mossy fiber and A/C input to CA3 pyramidal cells.     

Hypocarnitinemia in lysinuric protein intolerance

Carnitine deficiency in lysinuric protein intolerance (LPI) has been reported only in a single case. We describe hypocarnitinemia in a 11 year-old male patient with LPI and relate its development to intake, biosynthesis, and uptake of carnitine.