This case was a 40-year-old male patient with an immature lower left second premolar of open apex, and diagnosed with pulp necrosis and chronic apical abscess. We performed apexification and used mineral trioxide aggregate (MTA) barrier technique. One month after the apexification, the healing process was stable, and the tooth was restored with full coverage bonded porcelain restoration extending to the buccal side to achieve proper occlusal function and esthetic outcome. At two years follow-up recalling, the lesion was completely healed, and there were no adverse symptoms.