All-on-4® treatment concept: High rates of long-term clinical success
As global life expectancy continues to rise, our aging populations face increasing burdens of chronic disease and disability.1 Edentulism is a disability significantly impacting the quality of life of patients.1,2 Affecting an estimated 302 million people globally, edentulism increased 27.3% over a single decade.1
For many edentulous patients, the optimized esthetics, high stability and retention offered by a fixed restoration is an ideal solution for their dissatisfaction with the functionality and esthetics of dentures.3,4,5 The current expert consensus is that an implant-supported restoration should become the first choice for edentulous patients.6 For clinicians, addressing this continuing unmet medical need with advanced and clinically proven long-term solutions can help build their practice for the future.
One of the best-documented restorative concepts for edentulous patients is a fixed, full-arch prosthesis, immediately loaded onto two axial implants in the anterior and two tilted implants in the posterior.7,8 In the words of Paulo Maló, the All-on-4® treatment concept is “demonstrated to be a predictable treatment modality for full-arch rehabilitation with good results in the short, medium and long term”.7
- 1. Patient treated with the All-on-4® treatment concept in both the mandible an…
- 2. In the mandible: Predictable outcomes after 10–18 years follow-up
- 3. In the maxilla: High clinical success rates after 5–13 years of follow-up
- 4. Low rates of biological complications
- 5. The All-on-4® treatment concept is a fixed, full-arch treatment with up to 1…
Patient treated with the All-on-4® treatment concept in both the mandible and maxilla
Since 1998, more than 150,000 people have been treated with this procedure.9 With longstanding use of such a well-established restorative procedure, one would be right to expect that very long-term clinical evidence of its effectiveness and safety would now be available. This year, two publications from the Maló Clinic in Lisbon, Portugal, provided just that.7,8
In the mandible: Predictable outcomes after 10–18 years follow-up
Clinical outcomes after 10–18 years of follow-up were investigated among patients who had a mandibular rehabilitation with the All-on-4® treatment concept.7
The cumulative prosthetic survival rate was 98.8% (only 4 out of 471 patients lost their prostheses due to implant failures). Also, the implant cumulative survival and success rates* were 93.0% and 91.7%, respectively, from a total of 1,884 implants.
A total of 281 (out of 320) patients with mandibular restorations had periapical radiographs both from the day of surgery (baseline) and their 10-year follow-up visit. The average marginal bone loss was −1.7 mm (95% confidence interval: −1.6, −1.9 mm). Fewer than 10% of patients (n=27) exhibited >3 mm bone loss around their implants, with smoking (three-fold increased risk) and prior implant failure (almost four-fold increased risk) being the two most important risk indicators.
Mandibular implants supporting the All-on-4® treatment concept showed predictable outcomes over up to 18 years of follow-up.7
In the maxilla: High clinical success rates after 5–13 years of follow-up
Clinical outcomes after 5–13 years of follow-up were evaluated among patients who underwent a maxillary rehabilitation using the All-on-4® treatment concept.8
The prosthetic success rate was 99.2%; only 9 out of 1,072 patients lost their prostheses due to implant failures. The implant cumulative survival and success rates were 94.7% and 93.9%, respectively, from a total of 4,288 implants.
Among patients who had periapical radiographs from the day of surgery and after 10 years (n=129), the average marginal bone loss was −1.67 mm (95% confidence interval: −1.58, −1.77 mm). Patients who were smokers exhibited the greatest risk of increased marginal bone loss (a 67% increased risk for MBL >2.8 mm at 5 years).
Maxillary implants supporting the All-on-4® treatment concept showed predictable outcomes at up to 13 years of follow-up.9
Low rates of biological complications
Clinicians understand that biological and mechanical complications can occur with full-arch restorations, especially over a 10+ year time horizon.
In the two reports from the Malo Clinic, the incidence of biological complications at the implant level was 11.8% in the mandible (223/1,884 implants) and 7.8% in the maxilla (312/4,288 implants). Biological complications in the mandible were significantly associated with the previous failure of a neighbouring implant, smoking and systemic conditions, e.g. patients with cardiovascular disease or diabetes. In the maxilla, the main risk indicators were age and smoking. Smokers had a 57% increased risk of biological complications compared to nonsmokers.
During the up to 18-year follow-up period in the mandible, mechanical complications occurred in 29.5% of the provisional and 36.7% of the final prostheses. A considerable proportion of these were minor: the loosening of abutment or prosthetic screws in the provisional or definitive prosthesis. The lowest rates of mechanical complications were observed in patients with definitive prostheses comprising a titanium framework and all-ceramic crowns. In the maxilla, mechanical complications occurred in 58.8% of provisional prostheses and 7.3% of the final prostheses.
The All-on-4® treatment concept is a fixed, full-arch treatment with up to 18 years of documented clinical success
These two retrospective studies are real-world data unparalleled in their length of follow-up time and quantities of patients and implants. The impressive implant- and prosthetic success rates, together with preservation of marginal bone levels, confirm that the All-on-4® treatment concept is a predictable and effective long-term solution for patients burdened with edentulism. Also, by understanding the patient-specific factors such as smoking, age, gender and medical background, clinicians may optimize future outcomes when transforming patients’ smiles and lives.
* Implant success was based on the Maló Clinic success criteria: (1) implant fulfilled its intended function as support for reconstruction; (2) implant was stable when individually and manually tested; (3) no signs of persistent infection that could jeopardize the implant outcome; (4) no radiolucent areas around the implants, ; (e) good esthetic outcome of the rehabilitation; and, (5) allowed construction of a fixed prosthesis, which provided the patient with comfort and good hygienic maintenance.10
References
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2. Yamada J, Kori H, Tsukiyama Y, et al. Immediate loading of complete-arch fixed prostheses for edentulous maxillae after flapless guided implant placement: a 1-year prospective clinical study. Int J Oral Maxillofac Implants 2015;30(1):184-193.
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3. Albaker AM. The oral health-related quality of life in edentulous patients treated with conventional complete dentures. Gerodontology 2013;30(1):61-66.
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6. Feine JS, Carlsson GE, Awad MA, et al. The McGill consensus statement on overdentures. Mandibular two-implant overdentures as first choice standard of care for edentulous patients. Montreal, Quebec, May 24-25, 2002. Int J Oral Maxillofac Implants 2002;17(4):601-602.
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7. Malo P, de Araujo 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;21(4):565-577.
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8. Malo P, de Araujo 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;21(4):538-549.
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9. Nobel Biocare. Data on File.
10. Maló P, de Araújo Nobre MA, Ferro A, Parreira GG. Five-year outcome of a retrospective cohort study comparing smokers vs. nonsmokers with full-arch mandibular implant-supported rehabilitation using the All-on-4 concept. J Oral Sci 2018;60(2):177-186.
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