A randomised clinical trial on the use of intermediate bonding on the retention of fissure sealants in children.

OBJECTIVE: To assess whether an adhesive bonding agent increases the retention of resin fissure sealants on first permanent molars (FPMs) and to determine any difference in sealant retention on occlusal, buccal, or palatal surfaces. The effect of the child's behaviour on the retention of the sealants was also assessed. METHODS: One hundred and twelve children were recruited (age range 5-15 years). One operator placed sealants (Helioseal, Ivoclar Vivadent) on 390 FPMs using a split-mouth design. The study group, (n = 195), had an ethanol-based adhesive bond (ExciTEF, Ivoclar Vivadent) placed prior to sealant application, and no bond was used in the control group (n = 195). The sealants were reviewed after 12 months and analysed using Fisher's exact test. RESULTS: The addition of a bonding agent significantly increased sealant retention (P = 0.0005). Retention of bonded sealants on occlusal surfaces was higher (98%) than non-bonded sealants (93%) (P = 0.08). Bonded sealants placed on buccal/palatal surfaces were retained (92%) more successfully than non-bonded sealants (82%) (P = 0.0005). The behaviour of the patient significantly affected the retention of fissure sealants (P = 0.0001). CONCLUSIONS: The addition of an ethanol-based bonding agent significantly increased the retention of sealants at 12 months particularly on palatal fissures of maxillary first permanent molar teeth.

Development and validation of a stability-indicating HPLC method for the simultaneous determination of losartan potassium, hydrochlorothiazide, and their degradation products.

Losartan potassium was the first in a new class of potent angiotensin II receptor antagonists which are well-tolerated in the treatment of hypertension. Losartan potassium is the active ingredient in tablets COZAAR and is combined with diuretic co-active hydrochlorothiazide (HCTZ) in tablets HYZAAR for increased efficacy. Losartan potassium has one main impurity and two primary degradates. HCTZ has one major degradate as well as two common process impurities. Historically, separate methods have been used for the analysis of each active and their respective impurities and degradates. The ultimate goal of this work was to develop and validate a single high-performance liquid chromatography method selective for the eight main components of tablets HYZAAR. A single method was developed to afford simultaneous quantitation of actives and degradates for each of the two existing formulations. Each method is presented herein and demonstrated to be suitable for quantitation to 0.1% levels of all relevant degradates, as well as 100% levels of respective drug substances.

Forbidden knowledge. A case study with commentaries exploring ethical issues and genetic research.

This case is part of a series of case studies used as an exercise within a program on research ethics education. The case involves research on genetic birth defects in a culturally distinct, closed religious community in which elders speak for the community. The case raises ethical issues of informed consent in such a setting; of collaboration with the community; of conflicts between the researchers' responsibilities to the community as a whole and to individual subjects; of the impact of the researcher's findings on the practices and values of the community and issues regarding how the researchers share findings with subjects and how the findings are stored.