The preliminary results of a 5-year multi-center clinical investigation have been announced, revealing positive early outcomes for the Trefoil system.1 The aim of the study is to evaluate implant and prosthetic survival of the Trefoil system, the new treatment for mandibular edentulism and failing mandibular dentition that places a fixed prosthesis on three implants and achieves passive fit with a unique adjustable fixation mechanism.

Trefoil Bar

Positive survival rates for the Trefoil system

Dr. Kenji Higuchi and four principal investigators (Dr. Rubén Rosenberg, Dr. Rubén Davό, Prof. Dr. Massimo Albanese, and Dr. Glen Liddelow), located in practices across four continents, had placed 330 Trefoil Implants in 110 patients at close of recruitment in February 2017. These early results – comprising 6 months’ follow-up for 94 patients and 1 years’ follow-up for 40 patients – were presented by Dr. Higuchi at the EAO Congress on 5–7 October, 2017.

Trefoil system multi center study

Implant and prosthetic survival:

  • 98.2% implant cumulative survival rate at 6 months (n = 282), with 5 implant failures in 4 patients.
  • 97.6% implant cumulative survival rate at 1 year (n = 120), with 8 implant failures in 6 patients.
  • Only 2 prostheses were removed due to implant failure, and no additional prostheses failed.
 Implant survival rate

Soft and hard tissue health:

  • Marginal bone remodeling from implant placement to 6 months was −0.48 ± 1.14 mm (n = 177).
  • Soft tissue outcomes were ideal for most patients (>75%) across all parameters evaluated.

Soft tissue parameters

Improved quality of life

Oral health-related quality of life improved after prosthetic placement and improvements were sustained throughout the study period (n = 38).

Functional and esthetic satisfaction was very high (> 9.1) for all follow-up visits according to both patients and clinicians.

Fast time-to-teeth

The Trefoil system aims to help clinicians treat more edentulous patients with its fast workflow, pre-manufactured bar and the immediate loading of a fixed and final prosthesis, possible on the day of surgery*. In these preliminary results, 76.4% of patients received their fixed, final prosthesis within just 48 hours, and mean time-to-teeth was 2 days, 11.5 hours.


The Trefoil system demonstrates successful early clinical outcomes in terms of high implant and prosthetic survival rates, low marginal bone-level change, and short time-to-teeth.

  • Patients reported notable improvements in quality of life and, along with clinicians, reported excellent functional and esthetic satisfaction at all follow-ups after treatment.
  • The ability to immediately deliver a final fixed solution reduces chair and laboratory time compared with treatments requiring a provisional prosthesis.

The launch of the new Trefoil system has made the passive fit of a pre-manufactured bar possible for the very first time, using its revolutionary, adjustable fixation mechanism and just three implants. Now supported by successful early clinical outcomes at 1-year follow-up, it is an innovation that drives efficiency at every step and makes a fixed, full-arch implant solution a real possibility for more patients.

More to explore

*Depending on clinical preference and close cooperation with the laboratory. 


  1. Higuchi K, Davó R, Liddelow G, et al. An adaptive prefabricated full-arch framework on three implants in the mandible: preliminary results. Clin Oral Implants Res 2017;28(Suppl) The TREFOIL Concept 5 Year Clinical Investigation (NCT02940353).

Posted by Chris Kendall