Mechanisms of vitamin A metabolism and deficiency in the mammalian and fly visual system.

Vitamin A deficiency can cause human pathologies that range from blindness to embryonic malformations. This diversity is due to the lack of two major vitamin A metabolites with very different functions: the chromophore 11-cis-retinal (vitamin A aldehyde) is a critical component of the visual pigment that mediates phototransduction, while the signaling molecule all-trans-retinoic acid regulates the development of various tissues and is required for the function of the immune system. Since animals cannot synthesize vitamin A de novo, they must obtain it either as preformed vitamin A from animal products or as carotenoid precursors from plant sources.

A comparative evaluation of the efficacy of erbium: yttrium-aluminum-garnet and diode lasers in smear layer removal and dentin permeability of root canal after biomechanical preparation - A scanning electron microscopy study.

The chemomechanical preparation of root canal dentin with hand or rotary instruments creates debris and a smear layer. Root canal preparation (RCP) along with irrigants is not effective in cleaning apical portions, and hence, different laser activation systems were used for better cleaning in the apical third. Aim: The aim of this study is to compare the efficacy of erbium: yttrium-aluminum-garnet (Er:YAG) and diode laser irradiation in smear layer removal and dentin permeability after biomechanical preparation using scanning electron microscopic investigation.

Clinical and Practical Implications of Storage Media used for Tooth Avulsion.

Unlabelled: Replantation is being widely accepted as an effective treatment option for an avulsed tooth. However, the long-term fate of replanted teeth is unpredictable; it is dependent on various factors, such as the time interval between avulsion and replantation, extra-alveolar storage period (dry storage or storage media), the vitality status of pulp or periodontal tissues and the type and period of splinting. The appropriate use of storage media is an important clinical factor affecting the postoperative prognosis of avulsed teeth following replantation.

Management of pigmented gingiva in child patient: a new era to the pediatric dentistry.

Gingival health in the form of size, shape, consistency and appearance are essential components responsible for an attractive smile as well as may cause unpleasant appearance. Melanin pigmentation often occurs in the gingiva as a result of an abnormal deposition of melanin which can compromise the confidence level from the age of childhood. The present article describes and discusses the two cases of gingival melanin pigmentation in 12 and 13 years of female patient and their early surgical intervention with successful follow-up of 9 and 6 months.