Single-tooth Morse taper connection implants after 1 year of functional loading: a multicentre study on 302 patients

Purpose: This prospective clinical study evaluated the survival rate and the implant-crown success of 314 Morse taper connection implants, used for single-tooth replacement, after 1 year of functional loading. Materials and methods: Over a 4-year period (January 2003 to January 2007), 314 implants (168 maxilla, 146 mandible) were inserted in 302 patients (128 males, 174 females, aged between 23 to 79 years) in six different clinical centres. The sites included anterior (n = 118) and posterior (n = 196) teeth. To evaluate implant-crown success, the following clinical, prosthetic and radiographic parameters were assessed: modified plaque index (mPI), modified sulcus bleeding index (mBI), probing depth (PD), distance from the implant crown margin to the corona] border of the pen-implant mucosa (DIM), width of keratinised mucosa (KM), prosthesis function, and the distance between the implant shoulder and first crestal bone-implant contact (DIB). Success criteria included: absence of suppuration and mobility, PD<5.0 mm, absence of prosthetic complications, absence of continuous pen-implant radiolucency, and DIB<1.5 mm after 1-year of functional loading. Prosthetic restorations were all-ceramic (n = 116) and metal-ceramic (n = 198) crowns. Results: The implant survival rate was 98.4% (5 implant losses, 1 drop-out). A few prosthetic complications (0.6% implant-abutment loosening) were reported. The mean DIB was 0.887 +/- 0.308 mm. Among the survived implants (308), four did not fulfil the success criteria, giving an implant-crown success of 98.7%. Conclusion: The use of Morse taper connection implants represents a successful procedure for single-tooth replacement, in the anterior and posterior areas of both arches. The high mechanical stability may reduce prosthetic complications.