Effect of three different remineralising agents on prevention against acidic erosion of primary teeth: an in vitro study.

PURPOSE: This study aimed to evaluate and compare the protective effect of fluoride varnish (Enamelast™, Ultradent Inc., Cologne, Germany), casein phosphopeptide-amorphous calcium phosphate fluoride/CPP-ACPF (MI Paste Plus, GC Corp., Tokyo, Japan) and self-assembling P11-4 peptide (Curodont™ Protect, Credentis AG, Windisch, Switzerland), against acidic erosion of primary teeth. METHODS: Forty primary anterior teeth were randomly assigned to four groups (n = 10): group 1: control, group 2: fluoride varnish, group 3: CPP-ACPF and group 4: self-assembling P11-4 peptide. After applying remineralising agents, except for the control group, all specimens underwent an erosive challenge of carbonated soft drink and artificial saliva for 15 cycles of 6 s each at 6-h intervals for a day. Groups were compared in terms of surface microhardness, roughness readings, and surface scanning with an extra-oral scanner (D800; 3Shape A/S) before and after the erosive process. RESULTS: All experimental groups showed superior results than the control group regarding microhardness, surface roughness, and substance loss. The fluoride varnish group showed significantly favourable results in microhardness change. There was no significant difference between the experimental groups regarding surface roughness and enamel loss measurements. CONCLUSION: 5% NaF fluoride varnish, CPP-ACPF and self-assembling P11-4 peptide protect the enamel of primary teeth against erosion compared to artificial saliva alone.

Analysis of gene copy number changes in head and neck cancer.

OBJECTIVE: Chromosomal alterations and copy number changes are frequent events in tumors, leading to amplification of focal regions containing several oncogenes. Gains and losses of several regions have been reported in head and neck cancer (HNC) but the copy number changes of the individual genes located in these regions have not been analyzed so far. In this study we aimed to analyze the copy number variations in patients with HNC. DESIGN: Prospective study SETTING: University hospital PARTICIPANTS: 50 patients with squamous cell carcinoma of the head and neck METHODS: Copy number changes and amplifications of 22 genes in tumors and matched tissue were analyzed by MLPA which allows simultaneous analysis of gene copy numbers in multiple genetic regions. RESULTS: Amplifications were observed in 52% and losses were detected in 20% of the samples. Chromosome 8 was found to harbor the most frequent copy number alterations. The most frequently amplified genes were CCND1 and the MED1 genes followed by the MTDH and MYC genes on the long arm and ZNF703 on the short arm of chromosome 8. Amplification of the ZNF703, PRDM14 and MYC genes were highly correlated suggesting that the genes displaying high copy number changes on chromosome 8 collaborate during carcinogenesis. CONCLUSIONS: The alterations found in our study supports the contribution of gene amplifications and indicate cooperation between certain oncogenes in the pathogenesis of HNSCC. Correlations between amplification of less familiar genes and known oncogenes warrant further investigation. This article is protected by copyright. All rights reserved.