All on 4 treatment concept

Where patient-centric innovations and clinical science meet

Changing lives

All on 4 treatment concept magazine

In the early 1990s, Dr. Paulo Malo challenged the traditional methods of treating edentulous patients by introducing a groundbreaking innovation to the field of dental rehabilitation: immediate loading of a fixed full-arch prosthesis on just two straight and two tilted implants. The first edentulous patients were treated with what is called today, the All-on-4® treatment concept in 1990s. However, the dental community was not ready to accept this paradigm shift, and the inventor team had to wait several years before seeing their work in a peer-reviewed publication.1 

In their first retrospective clinical study with 44 patients, 176 immediately loaded Brånemark implants for the All-on-4® treatment concept were followed for 2 years and achieved cumulative survival rates of 96.7%. Since then, this innovation has become a standard practice in many dental clinics worldwide, providing patients with a predictable, and time- and cost-efficient treatment option.2

Patient stays at the center

Edentulism is estimated to affect over 350 million people globally.3 Implant-supported restorations are recognized as the optimal treatment solution for these patients.4 But the All-on-4® treatment concept raises the bar of patient centricity, by making it possible to deliver a fixed dental prosthesis and improving their oral health-related quality of life in just one day. For an edentulous patient who might have been suffering from impaired masticatory function, social handicap, and poor quality of life, receiving a fixed provisional prosthesis on the same day as their surgery is a transformative life experience. Patient-reported outcomes confirm the high degree of patient satisfaction with esthetics, phonetics, and function.5,6

But, is this solution delivered in one day predictable, too? Yes, as our science confirms. Today, the All-on-4® treatment concept is widely recognized as one of the most established solutions for edentulism, documented in more than 57 clinical studies, with over 24,300 anodized surface implants (TiUltra and TiUnite) in more than 4600 patients.7

Science matters

To the best of our knowledge, no other implant-supported clinical concept for treating fully edentulous patients has been backed by as many long-term clinical studies, systematic reviews, and meta-analyses, which are the highest-ranked types of evidence. Del Fabbro et al.’s comprehensive systematic review article is one of the most recent publications on this topic, to examine the efficacy of fixed full-arch prostheses supported by both axial and tilted implants.8 Out of 24 clinical studies which met the inclusion criteria, only 6 reported treatment outcomes were with implants manufactured by companies other than Nobel Biocare—confirming the significant role Nobel Biocare has played to advance clinical studies in this field. With 2637 patients including 1464 maxillary and 1271 mandibular arches, followed for up to 18 years, the cumulative survival rate was 93.91%, for implants, and 99.31% for prostheses, and comparable in peri-implant bone response between the treated jaw.

All on 4 infographics

Tilting the implants

Tilting posterior implants allows improved engagement of the existing bone. But, what effect does this have on stress distribution within the implant and the surrounding peri-implant bone?

In the clinical setting, Krekmanov et al. were possibly the first who published on “tilting of posterior mandibular and maxillary implants for improved prosthesis support.” Their analysis showed the distribution of load in tilted and non-tilted implants is comparable,9 which was later confirmed by finite element models,10,11 and suggested the tilted implants may even decrease the bone stress, due to the decreased cantilever area.

Today, more studies confirm that angulation of posterior implants in All-on-4® does not affect implant survival or marginal bone loss,12,13 based on results with up to 15 years of clinical follow-up.14

A long-term view is crucial

The longest follow-up clinical study we know for the mandibular arch has indeed been published by Malo et al.15 In their retrospective longitudinal study published in the Journal of Clinical Implant Dentistry and Related Research in 2019, authors followed 471 edentulous patients treated with the All-on-4® treatment concept for up to 18 years. 98.8% of the prostheses survived, and the implant survival rate was 93%. After 10 years, the marginal bone remodeling was -1.72 mm. In that same year, the team published the findings of yet another long-term clinical study, including 1072 patients treated with the All-on-4® treatment concept in the maxilla.16 After up to 13 years of follow-up, the prosthetic success was 99.2%, and implant cumulative survival was 94.7%. For implants that completed the 10-year follow-up, the marginal bone remodeling was -1.67 mm.

Another recent publication featuring true long-term outcomes of the All-on-4® treatment concept is the retrospective study of Agliardi et al. with 692 Nobel Biocare implants placed in 72 maxillae and 101 mandibles. After up to 15 years of function, the implant cumulative survival rate was 97.5% in the maxilla, and 96.9% in the mandible.14

Where our science is headed

Nobel Biocare has roots in science and clinical innovations. From believing in the young Paulo Malo in the early days of the All-on-4® treatment concept, to precision engineering, Immediate Function, digital dentistry, and now, introducing the era of Mucointegration™. The All-on-4® treatment concept with TiUltra™ implants and Xeal™ Multi-unit Abutments are currently being evaluated in several ongoing clinical trials, including a multicenter, prospective, non-interventional study with a total of 1000 patients in need of a single, multiple, or full-arch restoration.17  

Stay tuned and follow #sciencefirst on Nobel Biocare social media networks for information about the news on this study, and other real-world clinical evidence in dental implantology and regenerative science.

As said by Ralph Waldo Emerson, "The mind, once stretched by a new idea, never returns to its original dimensions."


1. Maló P, Rangert B, Nobre M. "All-on-Four" immediate-function concept with Brånemark System implants for completely edentulous mandibles: a retrospective clinical study. Clin Implant Dent Relat Res. 2003;5 Suppl 1:2-9.
Read on Pubmed

2. Babbush CA, Kanawati A, Kotsakis GA, Hinrichs JE. Patient-related and financial outcomes analysis of conventional full-arch rehabilitation versus the All-on-4 concept: a cohort study. Implant Dent. 2014 ;23(2):218-24.
Read on Pubmed

3. World Health Organization, "Global oral health status report: towards universal health coverage for oral health by 2030," 2022.
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4.Allen PF, McMillan AS. A longitudinal study of quality of life outcomes in older adults requesting implant prostheses and complete removable dentures. Clin Oral Implants Res. 2003;14(2):173-9.
Read on Pubmed

5. Sannino G, Barlattani A. Straight Versus Angulated Abutments on Tilted Implants in Immediate Fixed Rehabilitation of the Edentulous Mandible: A 3-Year Retrospective Comparative Study. Int J Prosthodont. 2016;29(3):219-26.
Read on Pubmed

6. Weinstein R, Agliardi E, Fabbro MD, et al. Immediate rehabilitation of the extremely atrophic mandible with fixed full-prosthesis supported by four implants. Clin Implant Dent Relat Res. 2012 ;14(3):434-41.
Read on Pubmed

7. Data on file. Nobel Biocare.

8. Del Fabbro M, Pozzi A, Romeo D, et al. Outcomes of Fixed Full-Arch Rehabilitations Supported by Tilted and Axially Placed Implants: A Systematic Review and Meta-Analysis. Int J Oral Maxillofac Implants. 2022 Sep-Oct;37(5):1003-1025.
Read on Pubmed

9. Krekmanov L, Kahn M, Rangert B, et al. Tilting of posterior mandibular and maxillary implants for improved prosthesis support. Int J Oral Maxillofac Implants. 2000 May-Jun;15(3):405-14.
Read on Pubmed

10. Huang HL, Lin TW, Tsai HL et al. Biomechanical Effects of Bone Atrophy, Implant Design, and Vertical or Tilted of Posterior Implant on All-on-Four Concept Implantation: Finite Element Analysis. 2022 J. Med. Biol. Eng. 42, 488–497.
Read online

11. Zampelis A, Rangert B, Heijl L. Tilting of splinted implants for improved prosthodontic support: a two-dimensional finite element analysis. J Prosthet Dent. 2007 Jun;97(6 Suppl):S35-43. 
Read on Pubmed

12. Chrcanovic BR, Albrektsson T, Wennerberg A. Tilted versus axially placed dental implants: a meta-analysis. J Dent. 2015 Feb;43(2):149-70.
Read on Pubmed

13. Gaonkar SH, Aras MA, Chitre V, et al. Survival rates of axial and tilted implants in the rehabilitation of edentulous jaws using the All-on-four™ concept: A systematic review. J Indian Prosthodont Soc. 2021 Jan-Mar;21(1):3-10.
Read on Pubmed

14. Agliardi EL, Pozzi A, Romeo D, et al. Clinical outcomes of full-arch immediate fixed prostheses supported by two axial and two tilted implants: A retrospective cohort study with 12-15 years of follow-up. Clin Oral Implants Res. 2023 Apr;34(4):351-366.
Read on Pubmed

15. Maló P, de Araújo Nobre M, Lopes A, et al. The All-on-4 treatment concept for the rehabilitation of the completely edentulous mandible: A longitudinal study with 10 to 18 years of follow-up. Clin Implant Dent Relat Res. 2019 Aug;21(4):565-577.
Read on Pubmed

16.Maló P, de Araújo Nobre M, Lopes A, et al. The All-on-4 concept for full-arch rehabilitation of the edentulous maxillae: A longitudinal study with 5-13 years of follow-up. Clin Implant Dent Relat Res. 2019 Aug;21(4):538-549.
Read on Pubmed

17. Identifier: NCT04737421.
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