Al-Shalan TA, Al-Musa BA, Al-Khamis AM Parents' attitude towards children's first dental visit in the College of Dentistry, Riyadh, Saudi Arabia. Saudi Med J. 2002 Sep;23(9):1110-4.
Arathi R, Ashwini R Parental presence in the dental operatory-parent's point of view. J Indian Soc Pedod Prev Dent. 1999 Dec;17(4):150-5.
Cox IC, Krikken JB, Veerkamp JS Influence of parental presence on the child's perception of, and behaviour, during dental treatment. Eur Arch Paediatr Dent. 2011 Aug;12(4):200-4.
An Objective Assessment of Dental Fear, and the Influence of the Parental Presence on the Behavior of Anxious Children on Their First Restorative Dental Visit
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.