Ana Ferro1,*; Miguel De Araújo Nobre2,3

1Oral Surgery, Maló Clinic, Lisboa; 2Research, Development and Education, Maló Clinic, Lisbon; 3Research, Development and Education, Maló Clinic, Lisboa, Portugal

Background: The All-on-4 concept represents a protocol for immediate function full-arch fixed prosthetic rehabilitation with good long-term outcomes. New surfaces have been recently developed for both dental implants (TiUltra) and abutments (Xeal) aiming to enhance both hard and soft tissue outcomes (osseointegration and mucointegration, respectively) in immediate function rehabilitation protocols. It is necessary to investigate the clinical outcome of such innovations in full-arch established protocols.

Aim/Hypothesis: The aim of this study is to evaluate the clinical outcomes (3 years) of full-arch rehabilitations through the All-on-4 concept using implants (TiUltra surface) and multi-unit abutments (Xeal surface).This pilot analysis reports the results of the 16 first consecutive patients at 1-year follow-up

Material and Methods: This prospective single cohort pilot study enrolled patients between February 2019 and January 2020 at a private rehabilitation center (Maló Clinic, Lisbon, Portugal) and it was approved by an independent ethics committee. In the pilot group, sixteen patients (10 women, 6 men; average age = 60.3 years) with full-arch rehabilitations ad modem All-on-4 concept with 64 implants (NobelParallel CC TiUltra; Nobel Biocare AB) and 64 Multi-unit abutments with Xeal surface (Nobel Biocare AB) in immediate function, supporting 16 fixed full-arch prostheses (maxillary: 11;mandibular: 5) were included. Follow-up clinical appointments were performed at 10 days, 2, 4, 6 months and 1 year.

Outcome measures were evaluated at 1-year follow-up. Primary outcome measures were prosthetic survival and implant success (estimated using life tables). Secondary outcome measures were marginal bone loss, biological and mechanical complications, plaque and bleeding indices. Descriptive statistics were computed.

Results: No patients withdrew from the study. No implant failures occurred, rendering a 100% cumulative implant and prosthetic success rate. The average (95% confidence interval) marginal bone loss at 1 year was 0.46 mm (0.32; 0.60). Mechanical complications occurred in 3 patients (18.8%) consisting of fracture of the provisional prosthesis (in 2 patients) and loosening of a prosthetic screw (in 1 patient); all complications resolved through mending the prosthesis in the dental laboratory. No biological complications occurred. One patient (1 implant) presented a probing pocket depth of 5 mm (pseudo-pocket). The plaque index mode was 1 (corresponding to mild plaque accumulation); the bleeding index mode was 1 (corresponding to an isolated bleeding spot visible). Both plaque and bleeding indices remained stable over the follow-up visits.

Conclusion and Clinical implications: Within the limitations of this pilot study, full-arch rehabilitations ad modem All-on-4 using dental implants with TiUltra surface and abutments with Xeal surface demonstrate low marginal bone loss and healthy soft tissue response at one year of follow-up. Future evaluations should be performed in higher sample size and longer follow-ups to examine the hard and soft tissue response, in particular the maintenance of stable soft tissue parameters and the incidence of peri-implant pathology.

Disclosure of Interest: A. Ferro Conflict with: Nobel Biocare, Conflict with: Nobel Biocare, Conflict with: Nobel Biocare, Conflict with: Nobel Biocare, Conflict with: Nobel Biocare, M. De Araújo Nobre Conflict with: Nobel Biocare, Conflict with: Nobel Biocare.

Keywords: biomechanical stability, immediate loading, implant surface