Objectives: The present consensus report critically evaluates the scientific evidence based on a comprehensive systematic review of the All-On-4 treatment concept, focusing primarily on the treatment indications, surgical procedures and prosthetic protocols, and secondarily on the mechanical and biological complications involved.
Material and methods: A systematic review was made in advance of the meeting. Consensus statements, treatment guidelines and recommendations for future research were based on within-group as well as plenary debates and discussions of the systematic review.
Results: The main indication of All-On-4 standard care is an atrophic maxilla or mandible, with or without remnant hopeless tooth. in ASA I or II patients. This surgical-prosthetic protocol seems efficient, safe and effective in the case of Cawood & Howell class IV, V and VI. It is necessary for the implant to have had an insertion torque of over 35 Ncm for immediate loading. The provisional prosthesis should provide rigidity, being non-flexible in order to avoid micro-movements, and should be strong enough to not fracture. Balanced occlusion without interferences is required, ensuring very gentle dynamic movements. The design of the definitive prosthesis must be cleanable and biomechanically adjusted to the implant position and individual characteristics of each patient. A non-concave acrylic base resting over soft tissue is recommended, facilitating hygiene. Regarding occlusion, a group guide should be made, taking into account whether the antagonist is not a removable complete denture. In that case, bi-balanced occlusion should be assessed. Prosthetic complications occur as a result of fractures of the provisional acrylic prostheses. These problems in turn can be resolved by repair through relining or fixing. The most frequent biological complication is the loss of at least one implant, while the second most frequent complication is the development of peri-implantitis and mucositis.
Conclusions: In the treatment of atrophy for full-arch implant supported restorations it is considered that four implants suffice for immediate loading and the final prosthesis, even when there is available bone between the mental foramina or maxillary sinuses. The weakness of the quality of the available evidence indicates that further studies are needed, involving an appropriate design and with adequate follow-up in All-On-4 standard care to confirm the present results mainly in relation to survival rates and complications. Key words:Atrophic jaw, All-on-4, immediate implant loading, edentulous mandible, edentulous maxilla, tilted implant, implant failure, dental implants.
Conflict of interest statement
Conflict of interest statement:The authors have declared that no conflict of interest exist.
Immediate loading in partially and completely edentulous jaws: a review of the literature with clinical guidelines.Periodontol 2000. 2014 Oct;66(1):153-87. doi: 10.1111/prd.12040. Periodontol 2000. 2014. PMID: 25123767 Review.
Immediate loading of fixed cross-arch prostheses supported by flapless-placed supershort or long implants: 1-year results from a randomised controlled trial.Eur J Oral Implantol. 2015 Spring;8(1):27-36. Eur J Oral Implantol. 2015. PMID: 25738177 Clinical Trial.
Immediate occluding definitive partial fixed prosthesis versus non-occluding provisional restorations - 4-month post-loading results from a pragmatic multicenter randomised controlled trial.Eur J Oral Implantol. 2016 Spring;9(1):47-56. Eur J Oral Implantol. 2016. PMID: 27022636 Clinical Trial.
Minimally invasive treatment of the atrophic posterior maxilla: a proof-of-concept prospective study with a follow-up of between 36 and 54 months.J Prosthet Dent. 2012 Nov;108(5):286-97. doi: 10.1016/S0022-3913(12)60178-4. J Prosthet Dent. 2012. PMID: 23107236 Clinical Trial.
State of the art and clinical recommendations in periapical implant lesions. 9th Mozo-Grau Ticare Conference in Quintanilla, Spain.J Clin Exp Dent. 2017 Mar 1;9(3):e471-e473. doi: 10.4317/jced.53600. eCollection 2017 Mar. J Clin Exp Dent. 2017. PMID: 28298994 Free PMC article. Review.
Cited by 1 article
Bone substitute made from a Brazilian oyster shell functions as a fast stimulator for bone-forming cells in an animal model.PLoS One. 2018 Jun 5;13(6):e0198697. doi: 10.1371/journal.pone.0198697. eCollection 2018. PLoS One. 2018. PMID: 29870546 Free PMC article.
- Gallucci GO, Benic GI, Eckert SE, Papaspyridakos P, Schimmel M, Schrott A. Consensus statements and clinical recommendations for implant loading protocols. Int J Oral Maxillofac Implants. 2014;29:287–90. - PubMed
- Agliardi E, Clerico M, Ciancio P, Massironi D. Immediate loading of full-arch fixed prostheses supported by axial and tilted implants for the treatment of edentulous atrophic mandibles. Quintessence Int. 2010;41:285–93. - PubMed
- Patzelt SB, Bahat O, Reynolds MA, Strub JR. The all-on-four treatment concept: a systematic review. Clin Implant Dent Relat Res. 2014;16:836–55. - PubMed