AIM: Direct pulp capping is the treatment of an exposed vital pulp with a dental material to facilitate the formation of reparative dentin and maintenance of vital pulp. A bioengineered drug delivery vehicle has the potential to increase the success rate of pulp capping. The aim of this study was to develop an injectable and light-curing drug delivery vehicle for endodontic treatment including direct pulp capping.METHODS: Polyethylene glycol-maleate-citrate (PEGMC) hydrogel was synthesized as a drug delivery vehicle that is composed of PEGMC (45% w/v), acrylic acid (AA) (5% w/v), 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) (0.1% w/v), and deionized water. The association between prehydrogel-solution volume and visible light-curing was examined. The cytotoxicity of the hydrogel was tested using L929 cells in a cell culture system. Ca(2+) release from the hydrogel was determined using calcium hydroxide as the incorporated medicine.RESULTS: The results showed that the light-curing time for hydrogel is comparable to composite resin. The hydrogel had cell toxicity similar to adhesive systems. Moreover, controlled Ca(2+) release was obtained from the calcium hydroxide incorporated hydrogel.CONCLUSIONS: The data suggest that hydrogel should be explored further as a promising drug delivery vehicle for vital pulp therapy and regenerative endodontics