Insertion of dental implants exhibits an increasing trend over the years on a global scale, becoming the best treatment option in terms of long-term success for replacing missing teeth [
Dental implant surface plays an important role in tissue interaction as well as in the rate and quality of osseointegration, as the design of the surface will influence the implant integration with the surrounding bone. Surface properties, chemical composition, hydrophilicity, and roughness are parameters that are crucial for the short- and long-term success of an implant [
Since its launch in 2000, more than 15 million implants with TiUnite surface (Nobel Biocare, Gothenburg, Sweden) have been used. The TiUnite surface (Nobel Biocare, Gothenburg) consists of a moderately rough thickened titanium oxide layer [
The advantages of this anodically oxidized surface include a higher osteoconductivity and a shortened healing phase [
Nevertheless, relatively few studies exist on the long-term outcome (with at least 10 years of follow-up) of implants with anodically oxidized surfaces inserted with immediate loading protocols: these studies registered cumulative survival rates over 96.5% at 10 years of follow-up [
There is a necessity of more studies investigating the long-term outcome (with at least 10 years) of implants with anodically oxidized surface inserted in immediate function.
The aim of this study was to evaluate the 10-year survival and marginal bone level outcomes of dental implants with anodically oxidized surface for support of fixed prosthetic rehabilitation in immediate function on both jaws.
This retrospective study was performed in Malo Clinic Lisbon (a private clinic in Portugal) from January 2001 (first implant insertion) to December 2012 (last follow-up appointment) and was approved by an independent ethical committee (Ethical Committee for Health, authorization number 004/2012).
The inclusion criteria for patient selection were the need for rehabilitation of single, partial, or full-arch maxilla or mandible through dental implants with anodically oxidized surface inserted with an immediate function protocol between January 2001 and January 2003. Exclusion criteria were patients rehabilitated through dental implants inserted in one-stage or two-stage surgical approaches, patients that underwent bone grafting procedures in the position of the implants, and patients rehabilitated with machined surface dental implants. These patients were identified from the medical records.
The rehabilitation procedure was divided into 2 treatment stages as per protocol: the first stage comprising the treatment planning, surgical intervention, immediate provisional prosthesis manufacture, and the maintenance appointments during the first 6 postoperative months and the second stage comprising the definitive prosthesis manufacture and the long-term maintenance.
A clinical examination with a preoperative panoramic radiograph and a computed tomography (CT) scan were used to plan the surgeries. The medication protocol was as follows: antibiotics before surgery and 15 days after surgery (Oraminax® 1 g, Wyeth Laboratories, Azevedos, Algés, Portugal); cortisone medication (prednisone 5 mg; Meticorten®, Schering-Plough Farma, Agualva-Cacém, Portugal), given daily in a regression mode (15 mg to 5 mg) from the day of surgery until 4 days postoperatively; anti-inflammatory medication (Nimed®, Rhône-Poulenc Rorer, Mem Martins, Portugal), administered for 2 days postoperatively starting on day 4; analgesics (clonixin 300 mg; Clonix®, Janssen-Cilag Farmaceutica, Barcarena, Portugal), given on the day of surgery and postoperatively for the first 3 days if needed; and antacid medication (omeprazole 20 mg; Generis, Lisbon, Portugal), given on the day of surgery and daily for 6 days postoperatively. The surgery was performed under local anesthesia (lidocaine hydrochloride 2% with epinephrine 1 : 100,000; Rapicaine®, Unipharm, Veracruz, Mexico). One operator (PM) performed the surgical procedures.
The insertion of the anodically oxidized surface implants followed the manufacturer’s standard procedures [
For full-arch edentulous rehabilitation [
Common to all types of rehabilitation, the drilling sequence was modified by employing underpreparation in order to secure a final torque of at least 30 Ncm before the final seating of the implant. Countersinking was used only when required to create space for the tilted implants’ head (
All implants underwent immediate loading. For single teeth or fixed partial prostheses, the intended final abutment (ranging from CeraOne, MirusCone, EsthetiCone, or Multiunit Abutments; Nobel Biocare AB) was inserted on the day of surgery and a provisional acrylic-resin crown/fixed partial prosthesis was connected (screw-retained). The occlusion was adjusted to eliminate direct contact to the prosthesis. After 6 months the patients received their permanent prosthetic reconstruction consisting of full-ceramic crowns (Procera Alumina or Zirconia; Nobel Biocare AB) or metal-ceramic fixed partial prostheses.
For full-arch rehabilitation, based on the impression, provisional full-arch acrylic-resin prostheses (PalaXpress Ultra, Heraeus Kulzer GmbH, Hanau, Germany) with titanium cylinders (Nobel Biocare AB) were manufactured at the laboratory and delivered on the day of surgery. Final acrylic-resin prostheses of the same type, metal-acrylic-resin prosthesis with a titanium framework (Procera® titanium framework; Nobel Biocare AB) and acrylic-resin teeth (PalaXpress Ultra, Heraeus Kulzer GmbH), or metal-ceramic prostheses with a titanium framework (Procera titanium framework; Nobel Biocare AB) and ceramic crowns (Procera Alumina crowns; Nobel Biocare AB) were delivered, respectively, at the earliest, 6 months after surgery.
The patients were instructed to have a soft food diet for the first four months after surgery. Ten days after surgery, the sutures were removed, and hygiene and implant stability (clinical mobility and suppuration by finger pressure) were checked. The occlusion was rechecked according to the initial protocol, a procedure that was repeated after 2 and 4 months. Usually, at around 4 months, the prostheses were again removed, jet-cleaned (using Air-Flow Powder, EMS, Nyon, Switzerland), and disinfected (using 0.2% chlorhexidine; Elugel, Pierre Fabre Dermo-Cosmetique), and the implants were checked for anchorage (clinical mobility), suppuration, and pain.
The patients were evaluated at 6 months after surgery, one-year after surgery, and thereafter every 6 months. The prosthesis was removed in every clinical appointment (except for single crowns) and the implants were evaluated in terms of stability.
Primary outcome measure was implant survival evaluated based on function and using the implant as unit of analysis. The implants survival was evaluated based on function and determined by fulfillment of the following criteria [
Secondary outcome measures were marginal bone level evaluated at 10 years of function using the implant as unit of analysis. A conventional radiographic holder (super-bite; Hawe Neos, Bioggio, Switzerland) was used, and its position was manually adjusted for an estimated orthognathic position of the film. An outcome assessor examined all implant radiographs. Each periapical radiograph was scanned at 300 dpi with a scanner (HP Scanjet 4890, HP Portugal, Paço de Arcos, Portugal), and the marginal bone level was assessed with image analysis software (Image J version 1.40 g for Windows, National Institutes of Health, Bethesda, MD, USA). The reference point for the reading was the implant platform (the horizontal interface between the implant and the abutment), and the marginal bone level was assessed and defined as the most apical contact between bone and implant. The measurements were performed on the mesial and distal sites, and average values were calculated. The radiographs were calibrated using the implant platform diameter. The radiographs were accepted or rejected for evaluation based on the clarity of the implant threads; a clear thread guaranteed both sharpness and an orthogonal direction of the radiographic beam towards the implant axis.
Survival was calculated using life table analysis. Descriptive statistics were computed for the variables of interest (marginal bone level). Cumulative implant survival rates were computed through life table analysis considering the overall, the implant site (maxilla, mandible), the type of restoration (single tooth, partial restoration, and full-arch restoration), the patients’ smoking status (smoker, nonsmoker), systemic status (healthy, systemic compromised), and parafunctional habits status (nonbruxer, bruxer). The average marginal bone level with corresponding 95% confidence interval (95% CI) was calculated overall and implant site specific and further evaluated according to the patients’ smoking, systemic, and parafunctional status. The data was analysed using the software SPSS for Windows version 17 (IBM SPSS, New York, USA).
The study included 75 patients (44 females and 31 males), with an age range of 29 to 88 years (mean age of 60 years). The medical status of the patients was established at implant insertion: fourteen patients with 57 implants were bruxers; twenty-one patients with a total of 69 implants were smokers; fourteen patients with a total of 56 implants had systemic conditions such as hepatitis, cardiovascular condition, thyroid condition, diabetes, rheumatologic condition, HIV, oncologic condition, and neurologic condition as presented in Table
Patient characteristics, number of implants per group, and number of failed implants according to the presence or absence of comorbidities, smoking habits, and bruxism habits.
Condition | Number of patients | Number of implants (implants failed) |
---|---|---|
Hepatitis | 1 | 8 |
Cardiovascular condition | 8 | 31 |
Thyroid condition | 2 | 4 (1) |
Diabetes | 2 | 8 |
Rheumatologic condition | 0 | 0 |
Smokers | 21 | 69 (2) |
HIV | 1 | 8 |
Oncological condition | 4 | 20 |
Neurologic condition | 2 | 13 |
One or more of the abovementioned conditions | 4 | 23 |
Heavy bruxers | 14 | 57 (0) |
Healthy patients | 37 | 126 (10) |
Total | 75 | 264 (12) |
A total of 21 patients (28%) with 66 implants (25%) were lost to follow-up: fifteen patients became unreachable and 6 patients passed away due to causes unrelated to implant treatment.
Seventy-five patients received 264 dental implants, 167 in the maxilla and 97 in the mandible. One hundred and nine of the inserted implants supported full-arch rehabilitation, 80 implants supported fixed partial prostheses, and 75 implants supported single tooth rehabilitation. From these 264 implants with moderately rough surfaces, 126 were Brånemark System MkIII (Nobel Biocare AB) implants (68 placed in the maxilla and 58 in the mandible) and 138 were Brånemark System MkIV (Nobel Biocare AB) implants (99 in the maxilla and 39 in the mandible) (Tables
Dental implants with external implant-abutment connection distribution by type of implant, diameter, and length.
Type of implants | Number of implants (implants failed) |
---|---|
Mk III 3.3 mm diameter: 10 mm of length | 2 |
Mk III 3.3 mm diameter: 11.5 mm of length | 1 |
Mk III 3.3 mm diameter: 13 mm of length | 6 |
Mk III 3.75 mm diameter: 15 mm of length | 7 (1) |
Mk III 3.75 mm diameter: 8.5 mm of length | 2 |
Mk III 3.75 mm diameter: 10 mm of length | 9 |
Mk III 3.75 mm diameter: 11.5 mm of length | 10 |
Mk III 3.75 mm diameter: 13 mm of length | 19 |
Mk III 3.75 mm diameter: 15 mm of length | 70 (8) |
| |
Total number of Mk III implants | 126 (9) |
| |
Mk IV 3.3 mm diameter: 8.5 mm of length | 6 |
Mk IV 4.0 mm diameter: 8.5 mm of length | 17 (1) |
Mk IV 4.0 mm diameter: 10 mm of length | 19 |
Mk IV 4.0 mm diameter: 11.5 mm of length | 9 |
Mk IV 4.0 mm diameter: 13 mm of length | 31 (1) |
Mk IV 4.0 mm diameter: 15 mm of length | 56 (1) |
| |
Total number of Mk IV implants | 138 (3) |
| |
Total number of implants | 264 (12) |
Implant type, position in the maxilla/mandible, and implant failures after 10 years’ follow-up.
Implant positions in the maxilla (number of implant failures) | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Implant position→ | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | Total |
MKIII implants | 1 | 0 | 4 | 1 | 10 | 4 | 12 (2) | 7 (1) | 9 (1) | 7 (1) | 3 | 5 | 3 | 1 | 1 | 0 | 68 (5) |
MKIV implants | 0 | 2 | 18 | 17 | 6 (1) | 1 | 5 | 7 | 4 | 3 | 4 | 6 (1) | 11 | 12 | 2 | 1 | 99 (2) |
| |||||||||||||||||
Implant positions in the mandible (number of implant failures) | |||||||||||||||||
Implant position→ | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | Total |
| |||||||||||||||||
MKIII implants | 0 | 2 | 2 | 7 (1) | 2 | 1 | 11 (1) | 1 (1) | 2 (1) | 12 | 2 | 4 | 6 | 4 | 2 | 0 | 58 (4) |
MKIV implants | 0 | 3 | 7 | 5 (1) | 0 | 0 | 1 | 1 | 0 | 3 | 0 | 0 | 6 | 6 | 6 | 1 | 39 (1) |
A total of 12 implant failures were registered in 6 patients: 9 Brånemark system MkIII implants and 3 Brånemark system MkIV implants. There were five implant failures in the first year, two implant failures in the second year, three implant failures in the fourth year, one implant failure after five years, and one implant failure after 9 years of follow-up. Five implant failures occurred in two patients with full-arch prostheses (4 implant failures and 1 implant failure occurred in mandibular full-arch prostheses supported by 6 implants and 4 implants, resp.) and with implant-supported prosthesis as opposing dentition: the first patient (healthy) with 4 implant failures due to infection (exhibiting probing pocket depths over 9 mm, with concurrent presence of bleeding on probing, suppuration, and marginal bone loss extending to the apical third of the implant) between 23 and 36 months (positions 31, 41, 42, and 45) in a full-arch prosthesis supported by 6 implants, had new implants inserted after 6 months (uneventful). One patient (smoker) with 1 implant failure after 53 months (position 45) due to infection (exhibiting probing pocket depths of 6 mm, with concurrent presence of bleeding on probing, suppuration, and marginal bone loss extending to the apical third of the implant) in a full-arch prosthesis supported by four implants had the prostheses adapted to be supported by the remaining three implants. One implant (position 14) failed after 8 years due to infection (exhibiting probing pocket depths of 6 mm, with concurrent presence of bleeding on probing, suppuration, and marginal bone loss extending to the apical third of the implant) in a healthy patient with a maxillary fixed partial prosthesis (supported by two implants) with natural teeth as opposing dentition: the failed implant was not reinserted and the patient had the prostheses adapted to be supported by the remaining implant. Six implants failed in 3 patients with maxillary single tooth rehabilitation: one healthy patient, with implant-supported fixed prosthesis as opposing dentition, lost 4 implants due to loss of osseointegration (positions 11, 12, 21, and 22) after one month and no implants were reinserted (the rehabilitation was transformed into a fixed prosthesis over natural teeth); another patient (smoker and with thyroid condition), with natural teeth as opposing dentition, lost 1 implant after one year due to loss of osseointegration (position 24) with the prostheses adapted to be supported by implants on positions 23 and 25; a third patient (healthy), with natural teeth as opposing dentition, lost one implant after 5 months due to loss of osseointegration (position 12) that was reinserted after 6 months (uneventful).
The overall implant cumulative survival rate (CSR) registered in this study was 95.2% at 10 years, with 95.6% for the maxilla and 94.7% for the mandible (Table
Cumulative survival rates for implants with anodically oxidized surface by total and per arch of rehabilitation.
Time | Total number of implants | Implant failures | Lost to follow-up | Follow-up not completed | Survival rate% | Cumulative survival rate% |
---|---|---|---|---|---|---|
Total number of implants | ||||||
0-1 year | 264 | 5 | 1 | 0 | 98.1% | 98.1% |
1-2 years | 258 | 2 | 10 | 0 | 99.2% | 97.3% |
2-3 years | 246 | 0 | 0 | 0 | 100% | 97,3% |
3-4 years | 246 | 3 | 5 | 0 | 98.8% | 96.1% |
4-5 years | 238 | 1 | 0 | 0 | 99.6% | 95.7% |
5-6 years | 237 | 0 | 6 | 0 | 100% | 95.7% |
6-7 years | 231 | 0 | 30 | 0 | 100% | 95.7% |
7-8 years | 201 | 0 | 12 | 0 | 100% | 95.7% |
8-9 years | 189 | 1 | 1 | 0 | 99.5% | 95.2% |
9-10 years | 187 | 0 | 1 | 0 | 100% | 95.2% |
10-11 years | 186 | 0 | 0 | 136 | 100% | 95.2% |
11-12 years | 50 | 0 | 0 | 45 | 100% | 95.2% |
| ||||||
Maxilla | ||||||
0-1 year | 169 | 5 | 1 | 0 | 97.0% | 97.0% |
1-2 years | 163 | 1 | 10 | 0 | 99.4% | 96.4% |
2-3 years | 152 | 0 | 0 | 0 | 100% | 96.4% |
3-4 years | 152 | 0 | 5 | 0 | 100% | 96.4% |
4-5 years | 147 | 0 | 0 | 0 | 100% | 96.4% |
5-6 years | 147 | 0 | 3 | 0 | 100% | 96.4% |
6-7 years | 144 | 0 | 17 | 0 | 100% | 96.4% |
7-8 years | 127 | 0 | 11 | 0 | 100% | 96.4% |
8-9 years | 116 | 1 | 1 | 0 | 99.1% | 95.6% |
9-10 years | 114 | 0 | 0 | 0 | 100% | 95.6% |
10-11 years | 114 | 0 | 0 | 78 | 100% | 95.6% |
11-12 years | 36 | 0 | 0 | 34 | 100% | 95.6% |
| ||||||
Mandible | ||||||
0-1 year | 95 | 0 | 0 | 0 | 100% | 100% |
1-2 years | 95 | 1 | 0 | 0 | 98.9% | 98.9% |
2-3 years | 94 | 0 | 0 | 0 | 100% | 98.9% |
3-4 years | 94 | 3 | 0 | 0 | 96.8% | 95.8% |
4-5 years | 91 | 1 | 0 | 0 | 98.9% | 94.7% |
5-6 years | 90 | 0 | 3 | 0 | 100% | 94.7% |
6-7 years | 87 | 0 | 13 | 0 | 100% | 94.7% |
7-8 years | 74 | 0 | 1 | 0 | 100% | 94.7% |
8-9 years | 73 | 0 | 0 | 0 | 100% | 94.7% |
9-10 years | 73 | 0 | 1 | 0 | 100% | 94.7% |
10-11 years | 72 | 0 | 0 | 58 | 100% | 94.7% |
11-12 years | 14 | 0 | 0 | 11 | 100% | 94.7% |
Cumulative survival rates for implants with anodically oxidized surface by total and type of reconstruction.
Time | Total number of implants | Implant failures | Lost to follow-up | Follow-up not completed | Survival rate% | Cumulative survival rate% |
---|---|---|---|---|---|---|
Full-arch | ||||||
0-1 year | 105 | 0 | 0 | 0 | 100% | 100% |
1-2 years | 105 | 1 | 0 | 0 | 99.0% | 99.0% |
2-3 years | 104 | 0 | 0 | 0 | 100% | 99.0% |
3-4 years | 104 | 3 | 0 | 0 | 97.1% | 96.2% |
4-5 years | 101 | 1 | 0 | 0 | 99.0% | 95.2% |
5-6 years | 100 | 0 | 0 | 0 | 100% | 95.2% |
6-7 years | 100 | 0 | 14 | 0 | 100% | 95.2% |
7-8 years | 86 | 0 | 8 | 0 | 100% | 95.2% |
8-9 years | 78 | 0 | 0 | 0 | 100% | 95.2% |
9-10 years | 78 | 0 | 1 | 0 | 100% | 95.2% |
10-11 years | 77 | 0 | 0 | 63 | 100% | 95.2% |
11-12 years | 14 | 0 | 0 | 14 | 100% | 95.2% |
| ||||||
Fixed partial prostheses | ||||||
0-1 year | 80 | 0 | 0 | 0 | 100% | 100% |
1-2 years | 80 | 0 | 3 | 0 | 100% | 100% |
2-3 years | 77 | 0 | 0 | 0 | 100% | 100% |
3-4 years | 77 | 0 | 0 | 0 | 100% | 100% |
4-5 years | 77 | 0 | 0 | 0 | 100% | 100% |
5-6 years | 77 | 0 | 0 | 0 | 100% | 100% |
6-7 years | 73 | 0 | 11 | 0 | 100% | 100% |
7-8 years | 62 | 0 | 1 | 0 | 100% | 100% |
8-9 years | 61 | 1 | 0 | 0 | 98.4% | 98.4% |
9-10 years | 60 | 0 | 0 | 0 | 100% | 98.4% |
10-11 years | 60 | 0 | 0 | 43 | 100% | 98.4% |
11-12 years | 17 | 0 | 0 | 14 | 100% | 98.4% |
| ||||||
Single teeth | ||||||
0-1 year | 79 | 5 | 1 | 0 | 93.6% | 93.6% |
1-2 years | 73 | 1 | 7 | 0 | 98.6% | 92.3% |
2-3 years | 65 | 0 | 0 | 0 | 100% | 92.3% |
3-4 years | 65 | 0 | 5 | 0 | 100% | 92.3% |
4-5 years | 60 | 0 | 0 | 0 | 100% | 92.3% |
5-6 years | 60 | 0 | 2 | 0 | 100% | 92.3% |
6-7 years | 58 | 0 | 5 | 0 | 100% | 92.3% |
7-8 years | 53 | 0 | 3 | 0 | 100% | 92.3% |
8-9 years | 50 | 0 | 1 | 0 | 100% | 92.3% |
9-10 years | 49 | 0 | 0 | 0 | 100% | 92.3% |
10-11 years | 49 | 0 | 0 | 30 | 100% | 92.3% |
11-12 years | 19 | 0 | 0 | 17 | 100% | 92.3% |
Implant survival curves according to the patients’ smoking status.
Implant survival curves according to the patients’ systemic status.
Implant survival curves according to the patients’ parafunctional habits status.
The average (95% confidence interval) marginal bone level for the anodically oxidized surface implants at 10 years of follow-up was 1.96 mm (1.71; 2.22), with 1.92 mm (1.61; 2.23) for the maxilla and 2.00 mm (1.58; 2.44) for the mandible (Table
Marginal bone level at 10 years for anodically oxidized implants in immediate function.
Descriptive statistics, number, and frequencies by total and distributed by arch of rehabilitation
Maxilla | Mandible | Total | ||||
---|---|---|---|---|---|---|
Average (mm) [95% confidence interval] | 1.92 [1.61; 2.23] | 2.00 [1.58; 2.44] | 1.96 [1.71; 2.22] | |||
Standard deviation (mm) | 1.31 | 1.71 | 1.50 | |||
Number | 73 | 63 | 136 | |||
| ||||||
Frequencies | | % | | % | | % |
| ||||||
0 mm | 3 | 4.1% | 0 | 0.0% | 3 | 2.2% |
0.1 to −1.0 mm | 19 | 26.0% | 21 | 33.3% | 40 | 29.4% |
1.1 to −2.0 mm | 25 | 34.2% | 23 | 36.5% | 48 | 35.3% |
2.1 to −3.0 mm | 10 | 13.7% | 8 | 12.7% | 18 | 13.2% |
>3.0 mm | 16 | 21.9% | 11 | 17.5% | 27 | 19.9% |
Discrimination of patients with implants with a marginal bone level (MBL) > 3.0 mm at 10 years
Patients | | Age | Gender | Patient characteristics |
---|---|---|---|---|
1 | 4 | 55 | Male | Smoker, HIV+, bruxer |
2 | 4 | 72 | Female | — |
3 | 3 | 56 | Male | Smoker |
4 | 2 | 50 | Female | Smoker |
5 | 2 | 52 | Male | Smoker |
6 | 2 | 57 | Female | Cancer |
7 | 2 | 60 | Female | Bruxer |
8 | 1 | 46 | Female | Smoker |
9 | 1 | 61 | Female | — |
10 | 1 | 61 | Female | Cancer |
11 | 1 | 60 | Female | Smoker |
12 | 1 | 51 | Male | Smoker |
13 | 1 | 87 | Female | — |
14 | 1 | 32 | Female | Smoker |
15 | 1 | 62 | Male | Smoker |
Patient with a fixed partial rehabilitation (implant positions #45 and #47) supported by two MkIII implants with anodically oxidized surface at 10 years of follow-up.
Patient with a single tooth rehabilitation (position #46) supported by an MkIV implant with anodically oxidized surface at 10 years of follow-up.
Error-bar plot illustrating the bone level at 10 years according to the patients’ smoking status. The average (95% confidence interval) bone level was 1.60 mm (1.37; 1.83) for nonsmokers and 2.95 mm (2.32; 3.58) for smokers. Note that the 95% confidence interval of the average (represented by the error bars) does not overlap, indicating a significant difference between both groups.
Error-bar plot illustrating the bone level at 10 years according to the patients’ systemic status. The average (95% confidence interval) bone level was 1.99 mm (1.70; 2.29) for healthy patients and 1.89 mm (1.36; 2.41) for systemic compromised patients. Note that the 95% confidence interval of the average (represented by the error bars) significantly overlaps indicating a nonsignificant difference between both groups.
Error-bar plot illustrating the bone level at 10 years according to the patients’ parafunctional habit status. The average (95% confidence interval) bone level was 1.87 mm (1.57; 2.16) for nonbruxers and 2.32 mm (1.80; 2.85) for bruxers. Note that the 95% confidence interval of the average (represented by the error bars) significantly overlaps indicating a nonsignificant difference between both groups.
The results registered in this study demonstrated a successful long-term outcome for implants with anodically oxidized surface placed exclusively in immediate function, with high cumulative survival rates at 5 and 10 years of follow-up and considering the high prevalence of patients with smoking habits (1/4 of the patients), systemic conditions (1/5 of the patients), and parafunctional habits (1/5 of the patients).
Concerning the type of prosthetic rehabilitation, cumulative implant survival rates around 98% were registered for full-arch rehabilitation performed with immediate loading in the mandible [
At 10 years of follow-up, the number of studies is scarce. Concerning studies with at least 10 years of function, Östman et al. [
It is important to notice that compared to the previously cited studies [
The marginal bone level registered in this study at 10 years (1.96 mm) was higher compared to the 1.6 mm of marginal bone level reported by Östman et al. [
The limitations of this study include the retrospective design, the single center, and more than 20% of loss to follow-up rate. Nevertheless, it is important to note the common correlation between long-term studies and a higher probability for loss to follow-up as previously reported [
Future investigations should focus on the long-term evaluation of these implants taking into consideration the soft tissue outcomes and the stratification according to different populations (healthy versus systemically compromised and smokers versus nonsmokers).
Within the limitations of this study and based on the 10 years’ outcome results, it is possible to conclude that fixed prosthetic rehabilitation supported by implants anodically oxidized surfaces in immediate function represents a valid treatment procedure.
This study was supported by Nobel Biocare Services AG, Grant 2014-1260. Paulo Maló is currently a consultant for Nobel Biocare. Miguel de Araújo Nobre, Yolande Gonçalves, Armando Lopes, and Ana Ferro have no conflict of interests.
The authors would like to thank Mr. Sandro Catarino and Mrs. Andreia de Araújo for all the help with data management.