Biology


Comments

Post a Comment

Popular posts from this blog

Alternative Coinitiators Applicable to Photocurable Resin Composites

Image
The composite resins available on the market today are mostly light-cured resins. So, photoinitiator molecules are included in these materials which have the ability to absorb light, and as result, generate free radicals which initiate the polymerization of these resin materials.  The light curing systems most commonly employed in the composites are the camphorquinone/amine system. The photoinitiator is camphorquinone, which requires a coinitiator to perform the polymerization process. Tertiary amines (aliphatic or aromatic) do not absorb light, but interact with the activated camphorquinone to produce reactive species. However, this photoinitiator system has some disadvantages, such as the tendency to promote yellowing to resin materials low compatibility with oral tissues   and even mutagenic characteristics. PDF LINK
Read more

Enostosis Mimicking a Supernumerary Tooth

Image
A 17 year old female with history of malaligned teeth was referred from orthodontist for extraction of a supernumerary tooth along with first premolars in lower jaw. This is a usual practice to gain space for future orthodontic treatment. The referral included an orthopantomogram revealing a dense, well defined radiopaque lesion in relation to the periapical region of lower left first and second premolars. It is horizontal in alignment measuring 2 cm inlength and 5 mm in width lying parallel to lower border in close proximity withroots of premolars. On examination, clinically there was no cortical bone expansion or enlargement on the labial or lingual side.  The patient did not show any signs or symptoms of infection. The orthodontist considered this radiopaque lesion (supernumerary tooth in jaw) to interfere with his orthodontic treatment or potentially cause resorption of roots.  In view of determining the proximity of this radiopacity to surrounding structures, we ...
Read more

Esthetic and Functional Rehabilitation of Molar Incisor Hypomineralisation: Report of Two Cases

Image
Molar-Incisor-Hypomineralisation (MIH) is a qualitative defect of 1-4 first permanent molars with or without the maxillary and mandibular permanent incisors. It seems to have been recognized first in the 1970s and prevalence varies between 2.8% and 25%, dependent upon the study. The term molar incisor hypomineralization (MIH) was introduced in 2001 to describe the clinical appearance of enamel hypomineralization of systemic origin affecting one or more permanent first molars (PFMs) that areassociated frequently with affected incisors.   Earlier condition was referred as hypomineralized PFMs, idiopathic enamel hypomineralization, dysmineralized PFMs, non-fluoride hypomineralization and cheese molars and is attributed to disrupted ameloblastic function during the transitional and maturational stages of amelogenesis. MIH’s clinical management is challenging due to: 1) the sensitivity and rapid development of dental caries in affected PFMs; 2) the limited cooperation of a ...
Read more