RESUMEN
The aim of this 3-year, randomized clinical trial (RCT) in split-mouth design was to explore the clinical survival of a Bis-GMA-free pit and fissure sealant (Helioseal F Plus) in comparison to a control material (Helioseal F). The initial population consisted of 92 adolescents. Follow-ups took place after one year (N = 85), two years (N = 82) and three years (N = 76) after application. At each examination, sealant retention and the presence of caries were recorded. The statistical analysis included the calculation of Kaplan-Meier survival curves, log-rank tests and a Cox proportional hazard regression model. No adverse events were documented. The proportion of completely intact sealants and those with minimal loss was almost identical in both groups, at 84.3% (Helioseal F; 113/134) and 81.7% (Helioseal F Plus; 107/131) after three years of observation. The regression analysis revealed an operator dependency, but no significant differences were found between the materials, the study centers, the chosen isolation technique, patient age or sex. After 3 years, 91.7% and 100.0% of all molars were free of non-cavitated carious lesions or carious cavities, respectively. It can be concluded that the new fissure sealing material can be considered as at least equivalent in terms of survival and retention behavior compared to the predecessor material.
RESUMEN
Based on a complete survey of homicides committed by young people between the age of 14 and 21 (juvenile and adolescent offenders) in the German state of Brandenburg during a period of 10 years, two typologies are presented to describe homicidal acts. The first typology is based on motivation and identifies the basic social attitude of the offender manifested in the concrete offence, whereas the typology based on group context deals with the social conditions influencing the offender in his actions in the youth group. Both are supported by comprehensive data regarding the personal and social circumstances of the offenders and offences. In the typology based on motivation, our study distinguishes between homicide committed out of conviction, homicide due to the social background and homicide for egoistic reasons in order to satisfy a sudden urge in an overpowering situation. In the typology based on group context, a distinction is made between solo and group offences with the latter being subdivided into emotional/non-emotional and planned/ unplanned acts. By typologizing offences according to motivation, perpetrators can be categorized according to their affiliation with a certain milieu and their emotional and ideological disposition. Contrary to conventional criminological studies, the typology according to group context suggests a high percentage of group-based violent crime, which has so far been described on the margin only.