7Van de Velde T, Sennerby L, De Bruyn H. The clinical and radiographic outcome of implants placed in the posterior maxilla with a guided flapless approach and immediately restored with a provisional rehabilitation:a randomized clinical trial[J].Clin Oral Implants Res,2010,21(11) : 1223-33.
8Hosseini M, Worsaae N, Schiodt M, et al. A 1-year randomised controlled trial comparing zirconia versus metal- ceramic implant supported single-tooth restorations[J].Eur J Oral Implantol, 2011,4(4): 347-61.
