Scientific highlights

Evidence matters – Highlights from 2019 scientific literature

Implant dentistry is a continually evolving field and, in 2019, Nobel Biocare unveiled several major innovations – all backed by scientific evidence. At Nobel Biocare, we take pride in our investment in research and development, which is one of the largest in the industry. One recent study showed that, in the past 20 years, Nobel Biocare implants were evaluated in a greater number of randomized, controlled trials than products from most of its competitors.1

As we look back over another successful year, we wanted to share the recent outputs from several of our collaborations with expert dental clinicians. The six publications described here highlight our clinical trials, surface innovation, and the total system performance of our implant–abutment connections and restorative solutions. They also demonstrate the durability and wide applicability of our solutions for edentulous patients.

Randomized controlled trial demonstrating the efficacy of barrier membranes

Clinical trials are considered by many to be the “gold standard” for scientific evidence. One example of our investment in randomized, controlled, clinical trials is a study that compared bone formation and soft tissue healing with creos™ xenoprotect – a natural collagen membrane – with a reference membrane, Bio-Gide® (Geistlich Pharma AG).2 In this trial, patients received either the reference membrane (n = 25) or creos™ xenoprotect (n = 24) during simultaneous guided bone regeneration and placement of NobelReplace® Conical Connection implants at single dehisced sites.2

From implant insertion to re-entry 6 months later, creos™ xenoprotect showed a high percentage defect fill and a low membrane exposure rate.3 At 12 months,2 implant survival and success rates were 100%.3 Across all other secondary outcomes improvements were seen: positive bone level changes (creos xenoprotect +0.01 mm, reference +0.42 mm); improved pink esthetic scores (creos xenoprotect 7.55 to 8.10, reference 6.48 to 7.48); overall better quality of life (OHIP-14 score of 6.5 pre-treatment to 1.9 at 12 months); excellent overall satisfaction with function and esthetics (visual analogue score of 9.9 and 9.7, respectively).3 Importantly, results for the creos™ xenoprotect group were similar to the reference membrane group (differences not statistically significant) showing non-inferiority.3

Taken together, this study demonstrates the efficacy of creos™ xenoprotect in facilitating bone gain to support successful implant placement.3

Find out about our natural collagen membrane, creos™ xenoprotect 

creos xenoprotect

Surface innovation benefiting soft tissue health with novel, anodized abutments

In 2019, Nobel Biocare introduced the Xeal™ and TiUltra™ surfaces. With their chemistry and topography, these innovative surfaces were developed with the goal to optimize early tissue integration and long-term tissue stability.

Prior to its market release, Hall and colleagues conducted a randomized, controlled, clinical study to investigate if the anodized, nanostructured Xeal™ surface could improve healing and soft tissue health compared with machined titanium abutments.4

Xeal surface

Anodized abutment surface, Xeal

Each of 35 subjects received one abutment with the Xeal™ surface and one machined titanium abutment.4 Throughout a 2-year follow-up, keratinized mucosal heights were observed to be significantly greater for abutments with the Xeal™ surface versus machined titanium abutments.4 There were no significant differences in biofilm formation between abutments with the Xeal™ surface versus machined titanium abutments. And, the investigators reported significantly lower soft tissue bleeding following removal of abutments with the Xeal™ surface versus machined titanium abutments at 6 weeks.4

This clinical study provides evidence that abutments with the anodized, nanostructured, Xeal™ surface improved surface-dependent peri-implant healing and soft tissue health versus machined titanium abutments.

Find out more about our pioneering Mucointegration™ surfaces Xeal and TiUltra

Total system performance: prospective demonstration of excellent clinical outcomes in the anterior maxilla

The choice of components that clinicians make undoubtedly influences how well patients’ restorations will function for years to come. When restoring anterior teeth, there is an additional prosthetic challenge of avoiding placement of the abutment screw hole too close to the incisal edge of the crown. Angulated screw channel (ASC) abutments provide one way to overcome this, offering flexibility and freedom also to place an implant in an optimal way given the available bone.

Friberg and colleagues initiated a prospective study in the Brånemark Clinic to evaluate NobelParallel™ Conical Connection implants in combination with authentic Nobel Biocare ASC abutments in single-tooth restorations in the anterior maxilla.5

In total, 51 NobelParallel™ Conical Connection implants were placed in 47 patients according to a two-stage surgical protocol.5 The interim results at 1-year follow-up showed a 98% cumulative implant survival rate, while mean marginal bone resorption was 0.41 mm (22 implants; standard deviation = 0.36 mm).5

These results confirm that NobelParallel™ Conical Connection implants demonstrate good treatment outcomes regarding implant survival and marginal bone preservation.5 Use of authentic, original-manufacturer ASC abutment ensured proper tightness at the implant–abutment connection, and no complications were observed.5

When clinicians choose Nobel Biocare solutions, they can be confident that the products they receive were designed and tested to fit and function perfectly together as a complete system.

Learn more about the versatility of NobelParallel™ Conical Connection implants and the restorative flexibility of our angulated screw channel solutions.

NobelParallel implant

(A) NobelParallel CC; narrow platform (NP) left, regular platform (RP) right.

The longest follow-up of the All-on-4® treatment concept

The All-on-4® treatment concept is a predictable treatment modality for full-arch rehabilitation with good results in the short, medium and long term.6

In this retrospective study, the very long-term clinical outcomes of 471 edentulous patients who received mandibular rehabilitations with the All-on-4® treatment concept, were investigated.6 An excellent cumulative prosthetic survival rate of 98.8% was observed after 10–18 years of follow-up.6 From a total of 1,884 implants, the cumulative implant survival and success rates were 93.0% and 91.7%, respectively.[6] The average marginal bone level change for patients who attended a 10-year follow-up visit was −1.7 mm (95% confidence interval: −1.6, −1.9 mm).6 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.6


All on 4 implant survival data

The incidence of biological complications at the implant level was 11.8%, and was significantly associated with the previous failure of a neighboring implant, smoking and systemic conditions.6 While mechanical complications occurred in 29.5% of the provisional and 36.7% of the final prostheses, a considerable proportion were minor: the loosening of abutment or prosthetic screws in provisional or definitive prostheses.6 The lowest rates of mechanical complications were observed in patients with definitive prostheses comprising a titanium framework and all-ceramic crowns.6

This study shows that high rates of long-term clinical success with predictable outcomes after 10–18 years can be attained with the All-on-4® treatment concept in the mandible.6

Find more about this study in our recent article, “All-on-4® treatment concept: High rates of long-term clinical success”.


Longevity of clinical success with maxillary full-arch restorations

Full‐arch rehabilitation of the edentulous maxilla according to the All‐on‐4® treatment concept is also a viable treatment option for the longer term.7

In this retrospective study, clinical outcomes after 5–13 years were evaluated among 1,072 patients who underwent a maxillary rehabilitation using the All-on-4® treatment concept.7

The prosthetic success rate was 99.2%; only 9 out of 1,072 patients lost their prostheses due to implant failures.7 The implant cumulative survival and success rates were 94.7% and 93.9%, respectively, from a total of 4,288 implants.7

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).7 Patients who were smokers exhibited the greatest risk of increased marginal bone loss (a 67% increased risk for bone loss >2.8 mm at 5 years).7

The incidence of biological complications at the implant level was 7.8%. Mechanical complications occurred in 7.3% of the final prostheses.7 The main risk indicators were age and smoking.7 Smokers had a 57% increased risk of biological complications compared to nonsmokers.7

Such high success rates with up to 13 years of follow-up are testament to the viability and longevity of the All‐on‐4® treatment concept.

Find more about this study in our recent article, “All-on-4® treatment concept: High rates of long-term clinical success”.

Maxillary implants supporting the All-on-4® treatment concept. Survival rate.

A large percentage of patients eligible for standardized treatment of the edentulous mandible

Nobel Biocare’s Trefoil™ system was developed with a time-efficient, template-guided clinical workflow and simplified laboratory protocol.8 But how well can an individualized fit be attained with a standardized, pre-fabricated restorative solution?

Trefoil system with denture

The Trefoil system’s pre-manufactured bar with a unique fixation mechanism can adjust to compensate for inherent deviations from the ideal implant position.9 That makes definitive teeth in a day a viable choice for more patients. (Depending on clinician preference and close cooperation with the laboratory)

In this study, cone beam computed tomography (CBCT) data from 100 partially and fully edentulous patients referred for full-arch mandibular restoration were used to evaluate the percentage of patients whose mandibular morphology could accommodate the standardized Trefoil restoration without any modification of the device.8

Using digital image analysis, CBCTs were registered to a reference CBCT of a patient treated previously with the premanufactured full-arch prosthesis.8 Bone height and thickness around simulated implants, distances to the incisive canal, mandibular arch width and semi-automated volume calculations were performed to evaluate patient eligibility.8

Using the system-specific 5.0-mm diameter implants with lengths of 13 mm and 11.5 mm, 85% and 86% of patients, respectively, were eligible for treatment with the standardized prosthesis.8 Eligibility was greater for men versus women (odds ratio = 3.9, p = 0.045) due to increased bone volume.8

This evidence suggests that, based on mandibular morphology, the Trefoil™ system can serve a large percentage of patients with edentulous mandibles or failing mandibular dentition.8

Find a course on full-arch rehabilitation so you can offer your patients the revolution in full-arch restoration.



1. Sarkis-Onofre R, Marchini L, Spazzin AO, Santos MBFD. Randomized controlled trials in implant dentistry: assessment of the last 20 years of contribution and research network analysis. J Oral Implantol 2019;45(4):327-333.
Read on PubMed

2. Urban I, Wessing B, Alández N et al. A multicenter randomized controlled trial using a novel collagen membrane for guided bone regeneration at dehisced single implant sites: Outcome at prosthetic delivery and at 1‐year follow‐ Clin Oral Implants Res 2019;30(6):487-497.
Read on PubMed

3. Wessing B, Urban I, Montero E, et al. A multicenter randomized controlled clinical trial using a new resorbable non-cross-linked collagen membrane for guided bone regeneration at dehisced single implant sites: interim results of a bone augmentation procedure. Clin Oral Implants Res 2017;28(11):e218-e226.
Read on PubMed

4. Hall J, Neilands J, Davies JR, et al. A randomized, controlled, clinical study on a new titanium oxide abutment surface for improved healing and soft tissue health. Clin Implant Dent Relat Res 2019;21(Suppl 1):55-68.
Read on PubMed

5. Friberg B, Ahmadzai M. A prospective study on single tooth reconstructions using parallel walled implants with internal connection (NobelParallel CC) and abutments with angulated screw channels (ASC). Clin Implant Dent Relat Res 2019;21(2):226-231.
Read on PubMed

6. 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.
Read on PubMed

7. 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.
Read on PubMed

8. Aouini W, Lambert F, Vrielinck L, Vandenberghe B. Patient eligibility for standardized treatment of the edentulous mandible: a retrospective CBCT-based assessment of mandibular morphology. J Clin Med. 2019;8(5).
Read on PubMed

9. Karl M, Carretta R, Higuchi KW. Passivity of fit of a novel prefabricated implant-supported mandibular full-arch reconstruction: a comparative in vitro study. Int J Prosthodont 2018;31(5):440–442.
Read on PubMed