Clinical and histologic evaluation of an enamel matrix protein derivative combined with a bioactive glass for the treatment of intrabony periodontal defects in humans.

Item does not contain fulltextThe present study clinically and histologically evaluated healing of human intrabony defects following treatment with a combination of enamel matrix derivative (EMD) and bioactive glass (BG) or BG alone. Six patients displaying either combined one- and two-walled (five patients) or three-walled (one patient) intrabony defects around teeth scheduled for extraction were included. A notch was placed at the most apical extent of the calculus on the root surface to serve as a reference. Six months after surgery, the teeth or roots were extracted, together with some of their surrounding soft and hard tissues, and processed for histologic evaluation; a gain of clinical attachment was found in all cases. Healing in all three defects treated with EMD + BG was mainly characterized by new cementum with inserting collagen fibers and new periodontal ligament; most graft particles were surrounded by bone-like tissue, indicating ongoing mineralization. Treatment with BG resulted in epithelial down-growth and connective tissue encapsulation of the graft material in all three specimens. Reformation of cementum and periodontal ligament was observed in one of the specimens, limited to the most apical part of the defect. Formation of bone-like tissue around the graft particles was observed in only one of the three specimens treated with BG. Direct contact between the BG particles and root surface (cementum or dentin) was not observed in any of the six specimens. BG alone has low potential to facilitate periodontal regeneration. However, EMD + BG resulted in formation of new cementum with an associated periodontal ligament, as well as enhanced mineralization around the BG particles

N-Heterocyclic dronic acids: applications and synthesis

Substituted hydroxymethylenebisphosphonic acid derivatives--either as dronic acids or their dronate sodium salts, are important pharmaceuticals in the treatment of diseases arising from excessive bone-resorption. Potential has also been identified in areas ranging from parasite-growth inhibition to immunological and cancer therapeutics. Representative clinically relevant N-heterocyclic derivatives include zoledronic and risedronic acids. The biochemical background and mechanism of action of these drugs are discussed, along with trends in structural development and future prospects. Synthetic routes to dronates are then summarized. The most popular route to valuable dronic acids involves the 3- component condensation of a substituted acetic acid, phosphorous acid, and phosphorus trichloride. However, the protocols recorded in the literature are very diverse. This review gives a critical account of reported methods, explores the contradictions and suggests a practical synthetic procedure after clarifying the inconsistencies described. Possible mechanisms of the reaction are also discussed