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-up.

OBJECTIVES: To compare clinical performance of a novel resorbable non-cross-linked collagen membrane (CXP) with a reference membrane (non-cross-linked resorbable membrane; BG) for simultaneous implant placement and guided bone regeneration (GBR) at dehisced single implant sites. MATERIALS AND METHODS: Preliminary data from this randomized controlled trial were reported previously; this is the 12-month report. The primary outcome measure was defected height at 6 months post-GBR. Secondary outcomes included implant cumulative survival rate (CSR) and success rate since placement; bone level changes, pink esthetic score (PES), and patient satisfaction since definitive prosthesis delivery; patient quality of life since pretreatment; and the 1-year bleeding index. Non-parametric statistical analyses were performed. RESULTS: Among patients, 24 were treated with CXP and 25 with BG. The 1-year implant CSR and success rate were 100% (n = 42). Bone level change between definitive prosthetic delivery and 1 year was not significantly different between the CXP and BG groups (BG + 0.42 mm, CXP + 0.01 mm). The PES increased from 7.55 to 8.10 for the CXP group and from 6.48 to 7.48 for the BG group; 1-year bleeding indices were 0 (16 CXP, 18 BG) and 1 (4 CXP, 2 BG). Patient quality of life changed from an OHIP-14 score of 6.5 at pretreatment to 1.9 at 1 year. Overall satisfaction (visual analogue score) with function and esthetics was 9.9 and 9.7, respectively. Inter-group differences were not significant for assessed outcomes. No device-related adverse events were reported. CONCLUSIONS: The use of CXP and BG for simultaneous implant placement and GBR at dehisced implant sites similarly reduced defect height and improved secondary measures, indicating non-inferiority.

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.

OBJECTIVE: To compare clinical performance of a new resorbable non-cross-linked collagen membrane, creos xenoprotect (CXP), with a reference membrane (BG) for guided bone regeneration at dehisced implant sites. MATERIALS AND METHODS: This randomized controlled clinical trial enrolled patients with expected dehiscence defects following implant placement to restore single teeth in the maxillary and mandibular esthetic zone and premolar area. Implants were placed using a two-stage surgical protocol with delayed loading. Bone augmentation material placed at the implant surface was immobilized with CXP or BG membrane. Soft tissue health was followed during the healing period, and the defect size was measured at reentry and 6 months after implant placement. RESULTS: Of the 49 included patients, 24 were treated with CXP and 25 with BG. Patient characteristics did not differ between the two arms. In the CXP arm, the defect height at implant insertion was (mean ± SD) 5.1 ± 2.1 mm (n = 24) and reduced at reentry by 81% to 1.0 ± 1.3 mm (n = 23). In the BG arm, the defect height at implant insertion was 4.9 ± 1.9 mm (n = 25) and reduced at reentry by 62% to 1.7 ± 2.1 mm (n = 24). Assuming a margin of non-inferiority of 1 mm, CXP was non-inferior to BG. Membrane exposure rate was highest at week 3 in both arms, reaching 16.7% for BG and 8.7% for CXP. CONCLUSIONS: The new resorbable non-cross-linked collagen membrane facilitates bone gain to support implant placement in expected dehiscence defects. The observed trend toward higher mean bone gain and lower exposure rate with CXP compared to BG should be further investigated.

Short, parallel-walled, conical-connection implants for a broad range of indications in the maxilla and mandible: Retrospective multicenter study with up to 33 months of follow-up.

OBJECTIVE: To evaluate the survival and complication rate of 7-mm short, parallel-walled, conical-connection implants in daily practice. METHOD AND MATERIALS: This multicenter retrospective study included 219 consecutive patients who received 323 implants. Indication was limited vertical bone height preventing placement of implants longer than 7 mm. Placement and loading protocols were determined on a case-by-case basis and included placement in fresh extraction sockets and healed sites, and loading was either immediate, early, or delayed. Patients were followed for up to 33 months. Outcome measures were implant survival rate and any biologic or technical complications. RESULTS: In total, eight implants in seven patients failed, accounting for the survival rate of 97.3% at implant level and 96.4% at patient level. The mean time to failure was 7.5 months and 10.2 months at the implant and patient level, respectively. The majority of patients (67.1%) received one implant and the placement was predominantly in healed sites (82.7%). Immediate loading was done for 21.4% of implants placed in the extraction site and for 21.3% of implants placed in healed sites. In most of the cases (71.8%) implants were placed in the premolar or molar position in the mandible. No complications were reported. CONCLUSION: These results suggest that in cases of limited vertical bone height, the short, parallel-walled, conical-connection implant can successfully support different prosthesis types in a wide variety of indications and loading protocols.

Guided surgery with tooth-supported templates for single missing teeth: A critical review.

AIM: To systematically scrutinise the scientific literature to evaluate the accuracy of computer-guided implant placement for single missing teeth, as well as to analyse the eventual clinical advantages and treatment outcomes. MATERIAL AND METHODS: The electronic and manual literature search of clinical studies published from January 2002 up to November 2015 was carried out using specified indexing terms. Outcomes were accuracy; implant and prosthetic failures; biological and mechanical complications; marginal bone loss (MBL); sulcus bleeding index (SBI); plaque score (PS); pink esthetic score [PES]; aesthetic and clinical outcomes. RESULTS: The search yielded 1027 relevant titles and abstracts, found during the electronic (n = 1020) and manual (n = 7) searches. After data extraction, and screening of titles, abstracts, and full-texts, 32 studies fulfilled inclusion criteria and were included in the critical review: two randomised controlled clinical trials, six prospective observational single cohort studies, one retrospective observational study, three in vitro comparative studies, 10 case reports and 10 systematic reviews. A total of 209 patients (18 to 67 years old) were treated with 342 implants using computer-guided implant surgery. The follow-up ranged from 12 to 52 months. The cumulative survival rate ranged from 96.5% to 100%. Eleven implant planning softwares and guided surgery systems were used and evaluated. CONCLUSIONS: Computer-guided surgery for single missing teeth provides comprehensive treatment planning, reliable implant positioning, favourable clinical outcomes and aesthetics. A tooth-supported template for the treatment of single missing teeth results in greater accuracy of implant positioning than with mucosa-supported or bone-supported templates. The limited scientific evidence available suggests that guided surgery leads to implant survival rates as good as conventional freehand protocols. Computer-guided surgery implies additional costs, that should be analysed in terms of cost-effectiveness, considering the reduction of surgery time, postoperative pain and swelling, as well as, the potential increased accuracy. Long-term randomised clinical trials are eagerly needed to investigate the clinical performance of guided surgery in partially edentate patients.

Five-Year Results of a Randomized Controlled Trial Comparing Patients Rehabilitated with Immediately Loaded Maxillary Cross-Arch Fixed Dental Prosthesis Supported by Four or Six Implants Placed Using Guided Surgery.

PURPOSE: To compare the 5-year clinical and radiological outcomes of patients rehabilitated with four or six implants placed using guided surgery and immediate function concept. MATERIALS AND METHODS: Forty patients randomly received four (All-on-4) or six (All-on-6) immediately loaded implants, placed using guided surgery, to support a cross-arch fixed dental prosthesis. Outcome measures were survival rates of implants and prostheses, complications, peri-implant marginal bone loss, and periodontal parameters. RESULTS: No drop-out occurred. Seven implants failed at the 5-year follow-up examination: six in the All-on-6 group (5%) and one in the All-on-4 group (1.25%), with no statistically significant differences (p = .246). No prosthetic failure occurred. Both group experienced some technical and biologic complications with no statistically significant differences between groups (p = .501). All-on-4 treatment concept demonstrated a trend of more complications during the entire follow-up period. A trend of more implant failure was experienced for the All-on-6 treatment concept. Marginal bone loss (MBL) from baseline to the 5-year follow-up was not statistically different between All-on-4 (1.71 ± 0.42 mm) and All-on-6 (1.51 ± 0.36 mm) groups (p = .12). For periodontal parameters, there were no differences between groups (p > .05). CONCLUSION: Both approaches may represent a predictable treatment option for the rehabilitation of complete edentulous patients in the medium term. Longer randomized controlled studies are needed to confirm these results.

A retrospective multicenter case series evaluating a novel 3.0-mm expanding tapered body implant for the rehabilitation of missing incisors.

OBJECTIVE: Narrow-diameter implants are indicated for narrow sites, small interdental/interimplant spaces, or sites with congenitally missing teeth. They also offer a substitute for invasive augmentation procedures. The authors retrospectively evaluated the performance of a new 3.0-mm diameter implant for rehabilitating small anterior spaces. METHOD AND MATERIALS: This observational multicenter retrospective case series included consecutive patients needing single-unit restoration for mandibular and lateral maxillary incisors. The outcome variables were: implant survival, Plaque Index, pocket probing depth (PPD), Jemt's papilla index, bleeding on probing (BOP), and marginal bone remodeling. RESULTS: In total, 45 patients received 58 3.0-mm implants placed in healed sites (n = 22), extraction sockets (n = 16), or sites with congenitally missing teeth (n = 20). Average follow-up time was 15.1 ± 5.2 months. Prosthetic loading was immediate (n = 23), early (n = 16), or delayed (n = 19). Two implants were lost, and two prosthetic complications occurred. One-year bone remodeling averaged -0.36 ± 0.85 mm (n = 44). PPD averaged 1.75 ± 0.58 mm. Neither BOP nor plaque was detected around implants. CONCLUSIONS: At 1-year follow-up, narrow 3.0-mm diameter implants placed in mandibular and lateral maxillary incisor sites demonstrate a high survival rate and support stable marginal bone levels and healthy soft tissue.

Five-year follow-up of immediate fixed restorations of maxillary implants inserted in both fresh extraction and healed sites using the NobelGuide™ system.

BACKGROUND: Transition from a hopeless dentition to an implant prosthesis, without wearing a removable denture, requires adaptation with guided surgery in postextraction cases. PURPOSE: The study aims to evaluate mid-term follow-up of patients with compromised dentition treated with immediate fixed restorations on maxillary implants inserted in fresh extraction and healed sites by using NobelGuide™ (Nobel Biocare AB, Gothenburg, Sweden) in combination with a specially designed radiographic stent. MATERIALS AND METHODS: Twenty-seven patients (females 20, males 7) aged 34 to 71 years (mean 55.8) were treated with flapless surgery. Immediate full-arch (n = 19) or partial (n = 10) restorations were delivered. Patients were followed both clinically (mean 61.3 months, 48-77) and radiologically for up to 5 years (mean 46.5 months, 12-61). Cumulative survival rate (CSR) was assessed. Marginal bone remodeling was evaluated at implant insertion, after 2 and 4/5 years. Soft tissue parameters as well as biological and mechanical complications were also recorded. RESULTS: One-hundred sixty implants were assessed. Four implants in two patients failed and were removed (overall CSR 97.33%), and two were replaced. All final prostheses were stable and in good function throughout the study. Bone loss from insertion to 2 years, for implants placed in both extraction and healed sites, was 0.85 mm (SD 1.28, n = 130); from insertion to last radiological control (4-5 years), 1.39 mm (SD 1.88, n = 127); and between 2 years and last control, 0.64 mm (SD 1.66, n = 111). No bone loss difference was found between extraction and healed sites at any time (p > .05). At the last visit, most implants showed normal mucosa. No other complications occurred. CONCLUSIONS: This 5-year retrospective study demonstrated a good outcome with regard to implant survival, marginal bone changes, and soft tissue conditions.

Immediate and early function of Brånemark System implants placed in the esthetic zone: a 1-year prospective clinical multicenter study.

BACKGROUND: Immediate/early implant function means great benefits for patients and therapists because treatment time and cost can be substantially reduced. This concept has become an accepted alternative for complete arch fixed restorations in the mandible, and clinical documentation is emerging for other indications. PURPOSE: The purpose of this prospective clinical multicenter study was to evaluate the outcome of implants placed in incisor, canine, and premolar regions in maxillas or mandibles. Implants were loaded with provisional crowns and bridges on the same day or within a few days and were followed up for 1 year during function. MATERIALS AND METHODS: Four centers treated 76 patients each in need of an implant-retained prosthesis in the anterior and premolar regions in the maxilla or mandible. A total of 116 titanium implants with machined surfaces (Brånemark System , Nobel Biocare AB, Gothenburg, Sweden) were placed: 74 in maxillas and 42 in mandibles. Eighty-seven prostheses were made, of which 63 were single crowns and 24 were bridges (supported by 53 splinted implants). Twenty-two implants in 14 patients were placed in fresh extraction sites. The goal with the preparation and insertion technique was to achieve good primary implant stability and a minimum implant insertion torque of 30 Ncm before the implant was completely seated. The occlusion was adjusted to eliminate direct contact with the provisional prostheses. After 6 months, the patients received their permanent prostheses. Sixty-seven patients were followed for 1 year. RESULTS: Five implants were lost in five patients, three in the maxilla and two in the mandible. Four of the lost implants were single-tooth replacements and one was splinted. The cumulative survival rate (CSR) was 95.7% for all implants after 1 year and 93.7% and 98.1% for single-tooth and splinted implants, respectively. There were no implant losses in the extraction sites. CONCLUSIONS: The CSR of 96% at 1 year indicates that immediate function of Brånemark System implants placed in incisor to premolar regions in both jaws is a viable concept. More failures occurred with single-tooth replacements (6.3%) than with splinted implants (1.9%).

Prospective multicenter study on immediate rehabilitation of edentulous lower jaws according to the Brånemark Novum protocol.

BACKGROUND: During recent years a new treatment concept, Brånemark Novum, has been developed in which implants are inserted in the edentulous lower jaw and immediately connected to a prefabricated titanium bar. A fixed prosthesis is then attached to the bar during or immediately following surgery. PURPOSE: The aim of the present study was to investigate the application of this concept under various settings, to determine technique sensitivity, and to evaluate the clinical outcome after 1 year of follow-up. MATERIALS AND METHODS: Fifty-one patients were included in a prospective multicenter investigation and followed up for 1 year. Cumulative implant survival rates were evaluated by life table analysis. In addition, clinical comparisons were performed to evaluate implant loss in relation to patient characteristics. Questionnaires were used to evaluate the treatment protocols and to obtain patients' opinions. RESULTS: The prosthetic treatment was completed on the same or the following day in 76% of the patients. The cumulative implant survival rates for implants and prostheses were 91% and 94%, respectively, after 12 months. CONCLUSIONS: The present study demonstrated that single-stage surgery and immediate loading of implants with prefabricated bridgework in the mandible can result in high implant success and significant reduction in treatment time, with patient satisfaction.

A two-center retrospective analysis of long-term clinical and radiologic data of TiUnite and turned implants placed in the same mouth.

PURPOSE: The gradual shift from using implants with turned surfaces to implants with moderately rough surfaces has raised questions regarding the long-term behavior of the latter. The aim of the present retrospective study was to compare clinical and radiographic data of the two implant surfaces using the "same mouth" approach. MATERIALS AND METHODS: A total of 122 consecutive patients were treated with both turned and TiUnite implants; however, 26 of these patients could not be reached for follow-up and were excluded from the study. The remaining 96 patients received 257 turned and 243 TiUnite Brånemark System implants, not necessarily supporting the same constructions and not necessarily inserted during the same session. Data were collected up to 10 years of function. RESULTS: During the first 6-year period, 18 turned implants and 1 TiUnite implant failed, resulting in implant cumulative survival rates (CSRs) of 93.0% and 99.1% for turned and TiUnite implants, respectively. During the following years, 1 turned and 3 TiUnite implants failed, resulting in CSRs of 90.3% and 96.6% for the two surfaces, respectively, a significant difference. A small but significant difference in mean bone level was seen between turned and TiUnite implants. CONCLUSION: Implants with turned and TiUnite surfaces showed comparable clinical and radiographic data during the study period. The early implant failure rate, as well as the overall failure rate, were significantly reduced when using TiUnite implants.