Biocompatibility of a resin-modified glass-ionomer cement applied as pulp capping in human teeth

Purpose: to evaluate the human pulp response following pulp capping with ca lcium hydroxide (CI-I, Group 1), and the resin-modified glass-ionomer Vitre bond (VIT, Group 2). Materials and Methods: Intact teeth with no cavity pre paration were used as control Group (ICG, Group 3). Buccal Class V cavities were prepared in 34 sound human premolars. After exposing the pulps, the p ulp capping materials were applied and the cavities were Filled using Clear fil Liner Bond 2 bonding agent and Z100 resin-based composite. The teeth we re extracted after 5, 30, and from 120 to 300 days, fixed in 10% buffered f ormalin solution, and prepared according to routine histological techniques . 6-mu m sections were stained with hematoxylin and eosin, Masson's trichro me, or Brown gr Brenn technique for bacterial observation. Results: At 5 da ys, CH caused a large zone of coagulation necrosis, The mononuclear inflamm atory reaction underneath the necrotic zone was slight to moderate. VIT cau sed a moderate to intense inflammatory pulp response with a large necrotic zone. A number of congested venules associated with plasma extravasation an d neutrophilic infiltration was observed. Over time, only CH allowed pulp r epair and complete dentin bridging around the pulp exposure site. VIT compo nents displaced into the pulp tissue triggered a persistent inflammatory re action which appeared to be associated with a lack of dentin bridge formati on. After 30 days a few histological sections showed a number of bacteria o n the lateral dentin walls. In these samples the pulp response was similar to those samples with no microleakage. VIT was more irritating to pulp tiss ue than CH, which allowed pulp repair associated with dentin bridge formati on. These results suggested that VIT is not an appropriate dental material to be used in direct pulp capping for mechanically exposed human pulps.