Chromosomal breakpoints in a cohort of head and neck squamous cell carcinoma patients.

Head and neck squamous cell carcinoma (HNSCC) presents complex chromosomal rearrangements, however, the molecular mechanisms behind HNSCC development remain elusive. The identification of the recurrent chromosomal breakpoints could help to understand these mechanisms. Array-CGH was performed in HNSCC patients and the chromosomal breakpoints involved in gene amplification/loss were analyzed. Frequent breakpoints were clustered in chromosomes 12p, 8p, 3q, 14q, 6p, 4q, Xq and 8q. Chromosomes 6, 14, 3, 8 and X exhibited higher susceptibility to have breaks than other chromosomes. We observed that low copy repeat DNA sequences are localized at or flanking breakpoint sites, ranging from 0 to 200 bp. LINES, SINES and Simple Repeats were the most frequent repeat elements identified in these regions. We conclude that in our cohort specific peri-centromeric and telomeric regions were frequently involved in breakpoints, being the presence of low copy repeats elements one of the explanations for the common rearrangement events observed.

Evaluation of the efficacy of a 2-step etch-and-rinse, 2-step self-etch and 1-step self-etch adhesive systems, in class II primary molars restorations. An one year prospective, randomized clinical trial.

PURPOSE: To evaluate the clinical efficacy at 6 months (6 M) and 12 months (12 M) of 3 adhesive strategies (two-step etch-and-rinse; two-step self-etch; one step self-etch) used in composite resin restorations in primary molars. METHODS: This randomized clinical study involved 101 class II restorations in primary molars of 34 children (4-8 years old), distributed by 3 groups according to the 3 tested adhesive systems: GI- ClearfilTMS3Bond Plus (CSB); GII- ClearfilTMSE Protect Bond (CSEPB); GIII- Prime&Bond®XP (PBXP). Restorations were evaluated according to FDI criteria, immediately after execution, at 6 M and 12 M. All ethical and legal requirements were met. Statistical analysis was performed using IBM®SPSS®v26 and MS Excel® (5% significance level). RESULTS: The aesthetic, biological and most of the functional parameters evaluated remained without significant changes over time. Statistically significant differences were only found regarding the "marginal adaptation" parameter at 12 M, with worsening of scores for the three groups (p < 0.001). Comparing the groups, no significant differences were detected between any of the evaluated parameters (aesthetics properties: p = 0.721; functional properties: p = 0.122). CONCLUSIONS: After a one-year period, the self-etch adhesives tested presented a clinical efficacy similar to the etch-and-rinse adhesive in restoring class II cavities in primary molars. TRIAL REGISTRATION NUMBER: ISRCTN11458186.

Prevalence and sociobehavioural determinants of early childhood caries among 5-year-old Portuguese children: a longitudinal study.

PURPOSE: To assess the prevalence of early childhood caries (ECC) and associated factors among a 5-year-old cohort. METHODS: An observational longitudinal study was conducted with a sample of 142 preschoolers. A calibrated dentist performed intraoral examinations following International Caries Detection and Assessment System (ICDAS-II) criteria at baseline and after 6 months. A questionnaire on sociodemographic variables and oral health-related behaviours was answered by caregivers. Statistical analysis included descriptive statistics and computation of confidence intervals (95% confidence level). RESULTS: Baseline prevalence of ECC and severe ECC (S-ECC) were 40.1% and 11.3%, respectively. After 6 months ECC and S-ECC prevalence rates were 46.5%, and 13.2%, respectively. At both evaluations most caries lesions were untreated. Parental education and occupation were significantly associated with ECC. Behaviour variables found to be significantly associated with the disease comprised: establishing toothbrushing habits before the first year, toothbrushing twice daily and with parental assistance, frequency of dental visits, age at first dental visits, daily ingestion of sweets and number of daily meals. CONCLUSION: The prevalence of ECC was very high, with most of the lesions left untreated. ECC experience was associated with participants' socioeconomic background and several of the surveyed oral health-related behaviour variables.