Nobel Biocare Implants Research Articles

A Comparative Evaluation of Stress Distribution Around Different Widths of Implant and Bony Interface in Function During Axial and Non-axial Loading: A Finite Element Analysis.

The study employed three-dimensional (3D) finite element analysis (FEA) and examined how implant diameters affect stress distribution across the implant-bone contact and how stress transmission through this interface changes during axial and non-axial loading. A 3D mandibular model was created using cone beam CT of a patient with implants inserted into the first mandible molar. Nobel Biocare implants (Nobel Biocare, Switzerland) with specific dimensions of 3.5 mm, 4.3 mm, 5.0 mm, and 6.0 mm were chosen. Models were created in CATIAV5R19 (Dassault Systemes, France) from threaded titanium implant dimensions. Implants were finite element-modeled utilizing ANSYS Workbench v11.0 (Ansys, Inc, Pennsylvania, USA). The analysis involved applying 100 N axial, 50 N buccolingual, and 50 N mesiodistal loads. In a lower first molar bone segment, the implant top surface was loaded in 100 N axial, 50 N buccolingual, and 50 N mesiodistal orientations. The cortical bone proximal to the implant neck had the most von Mises stress, regardless of model or stress scenario. In Model I cortical bone, maximal stress was centered at the implant neck. Most stress was on lingual bone plates, lesser on buccal, and least on mesial and distal. Less than half of the implant stress was transmitted to the cortical bone. The stress transferred from the implant to the cortical bone in Model II was less than half of the implant stress. The same was true for Models III and IV. In Model I cancellous bone, stress was concentrated in the implant's coronal half and minimal in the apical half. The stress patterns under axial loading were distributed favorably. Therefore, it can be inferred that an augmentation in the diameter of the implant enhances the even distribution of stress at the interface between the bone and the implant by offering a larger surface area for the dispersion of stress. Furthermore, it was determined that applying force along an implant's axis was a beneficial loading direction and did not negatively impact its lifespan.

Surface Modifications of Commercial Dental Implant Systems: An Overview.

The aim of this review was to perform a comprehensive overview of evidence pertaining to the influence of various surface modifications on the surface roughness, bone implant contact, and the success and complication rates of the implants. Modified sandblasted, large-grit, acid-etched (SLA) implants (SLActive implants) have a higher implant stability quotient compared with conventional SLA implants. Also, when compared between the implant surfaces from various manufacturers, Biomet 3i Nanotite implants were shown to have a relatively higher implant stability quotient compared to Straumann implants as well as the Biomet Osseotite implants. Only one study reports the insertion torque values as obtained by the various implant surfaces, with the findings being statistically similar for all the types, and a higher mean value for Biomet 3i Nanotite implants. Among SLA and SLActive surfaces, the latter was found to have a lower marginal bone loss, and among Astratech implants, the marginal bone loss levels were similar for Osseospeed and Tioblast surfaces. When Osseospeed, TiUnite and SLActive surfaces were compared, Osseospeed was found to have the minimum bone loss while TiUnite was found to have the highest. The bone implant contact percentages are similar and satisfactory for most of the implant surface modifications that are available currently. Upon assessing the recent literature on the survival rates for implants with various surface modifications, it was found that among Nobel Biocare implants, the survival rate was higher for TiUnite implants, compared with the turned surfaces. Surprisingly, among the Straumann implant surfaces, the survival rates were found to be higher for the SLA implants when compared to the modified SLA implants. Only one of the included studies evaluated the survival rate for Astratech implant surfaces and found a 100% survival rate for both the Osseospeed and Tioblast surface implants. Therefore, major advancements have been made in developing novel surfaces of dental implants. The numerous innovations set the stage for rehabilitating patients with high success and predictable survival rates even in challenging conditions.

Macroscopic Evidence of Surface Changes of Dental Implants After Insertion and Removal in Dense Bone: In Vitro Study.

Titanium and zirconium wear are discussed in the literature as contributing factors for mechanical complications. The purpose of this study was to evaluate if current implant designs present visible clinical evidence of surface damage after insertion and removal in dense bone and if these changes are comparable in titanium and zirconia implants. For this experimental in vitro and pilot study, four implant systems were evaluated. Astra Tech Implants (Dentsply Sirona), Nobel Biocare Implants (Nobel Biocare), Straumann Implants (Institut Straumann), and Zeramex Implants (Dentalpoint). Six implants of each group with similar lengths (between 10 and 11 mm) and diameters (between 4.0 and 4.5 mm) were used. Protocols for implant bed preparations in dense bovine bone disks represented type II bone density. The implants were inserted and removed to evaluate the changes experienced by their surfaces using a magnification compatible with 5× magnification of the clinical setting. The presence or absence of damage and type of damage were evaluated at the coronal, middle, and apical regions at higher magnification. The Cochran Q test for binary dichotomous samples was used for statistical comparisons. All the groups showed surface changes; titanium implants showed abrasion at the threads' flanks, and zirconia implants showed microfractures at the tip of the threads. Due to the insertion and removal of titanium and zirconia implants in dense bone, the flanks and tips of the implant threads will develop visible surface damage.

Three-Year Evaluation of the Influence of Implant Surfaces on Implant Failure and Peri-implantitis: A Double-Blind Randomized Controlled Trial with Split-Mouth Design.

To compare the onset of peri-implantitis, incidence of failure, and peri-implant marginal bone level changes between implants with a roughened surface and those with a machined/turned surface. All patients needing two dental implants of the same size on the left and right sides of the same arch, and not scheduled for immediate loading, were enrolled between October 2012 and February 2016. The patients were randomly allocated either to Nobel Biocare MKIII or Sweden & Martina Outlink2. Rough-surface implants and machined-surface implants were used from each company. After the preparation of two identical implant sites, each implant (rough or machined of the same group) was randomly allocated to the right and left sides of the same patient, following a split-mouth design. Outcome measures were peri-implantitis onset, incidence of failure, and peri-implant marginal bone level changes. Patients were followed up for 3 years after loading. One hundred fourteen patients were enrolled and treated; nine patients dropped out. Following an intent-to-treat analysis to avoid overestimation, proportions are given related to the initial number of 114 patients. Peri-implantitis incidence was 4.39% for machined implants (5/114), 0.88% for rough implants (1/114), 1.75% in the Nobel Biocare group (2 cases), and 3.51% in the Sweden & Martina group (4 cases). The failure rate was 1.75% in machined implants (2/114), 0.88% in rough implants (1/114), 0.98% in the Nobel Biocare group (1/114), and 1.85% in the Sweden & Martina group (1/114). No statistically significant differences in marginal bone loss were found comparing different surfaces, while marginal bone loss was significantly lower in Nobel Biocare than in Sweden & Martina implants. Based on the results of this study, no significant differences can be demonstrated in either peri-implantitis or failure rate or in marginal bone loss between rough and machined implants. Marginal bone loss was significantly worse in machined-surface Sweden & Martina than in rough-surface Nobel Biocare implants.

Five-year survival rates for implants placed using digitally-designed static surgical guides: a systematic review.

Digitally-designed static surgical guides provide an acceptable level of accuracy and predictability for the placement of dental implants. However, to our knowledge, few published studies have compared the long-term survival of implants placed in this way with those placed using other methods. A systematic search of electronic databases using a population, intervention, comparison, and outcome (PICO) framework was conducted of Medline and EMBASE, as well as grey literature and hand searches, to obtain all relevant work pertaining to the survival of dental implants placed by guided surgery. The studies were required to have at least 10 patients with a follow up of at least five years. A total of 621 titles were screened. Four studies met the inclusion criteria for quantitative analysis, and they all reported the exclusive use of Nobel Biocare implants and the NobelGuide system (Nobel Biocare Services). Cumulative survival rates ranged from 94.5% to 100% over five years. The survival rates of implants placed using digitally-designed static surgical guides are comparable to the estimated overall survival rate (95.6% over five years), despite the complex nature of the treatments done with guided surgery. Clinicians who do these operations should, however, have the experience and ability to revert to conventional freehand techniques if complications arise.

Criterion assessment system of the actual level of expertise of dental professionals practicing implant dentistry

The aim of the study was to develop criterion assessment system of the actual level of expertise of dental professionals practicing Implant dentistry. The study comprised fifteen dental experts aged from 35 to 47 years with the average 15 years clinical experience. For evaluation of the clinical portfolio of the dentists we developed 10 reference points and to ensure unification of the assessment approach we organised consensus methodical conference for our expert group. Scores were applied by parity of reasoning with point-rating system applied in continuing education programs of Medical University. Assessment of 43 clinical portfolios with short term and long term results of implant supported restorations was performed. Treatment was provided with the use of Nobel Biocare implants and prosthodontic rehabilitation was achieved with the use of CAD/CAM 'Procera' technology. The study showed that dentists who practice implant dentistry from 1 to 7 years have good manual skills and clinical expertise sufficient for achieving positive treatment outcome. At the same time in general their actual diagnostic skills are not sufficient, they misapply additional diagnostic methods, do not perform risk analysis of potential clinical complications that leads to shifting responsibilities on the patients in case of complications emergence. Methods of Computer Assisted Design are widely popular during all stages of rehabilitation (diagnostic, surgical stent, final prosthesis framework). Actual level of expertise of dental professionals doesn't depend on sex distribution. Males and females who practice implant dentistry have similar levels of clinical expertise.

Survival of Implants after Indirect Maxillary Sinus Elevation Procedure: A Two Years Longitudinal Study

The aim of the study was to evaluate the survival rate of two diverse implant systems with different implant surfaces with the same geometrical design. One hundred fifty patients were included in the study in which 95 were males and 55 were females and 150 implants were placed using indirect sinus floor elevation technique and only one implant was placed in each subject and they were categorized into two groups of 100 in group A and 50 in group B as per two different implant systems. At review appointments, implants were tested clinically and radiographically and were examined for signs of infection. The patients were examined periodically after placement of the implants, and follow-up was conducted annually. Results of the Chi-square analysis showed no significant association between the type of implant surface and rate of success or failure of the implant. There was no significant difference between the observed and expected frequency of successful implants in group A as well as group B, indicating that the surface type of implant had no significant association with the success of the implant in group A and B. To date, there is no consensus in the literature regarding the best surface and even on the macrotopography of the implants for better osseointegration. However, Surface treatments improve the result of osseointegration, especially in the early stages, benefiting bone affixation with qualitative and quantitative enhancements. In the present study, we achieved clinical success with both kinds of implant surfaces however Bioetched implant surface showed promising results comparable to Tiunite surface of Nobel BioCare Implants. In the future, more case-controlled studies with longer follow-up are needed to validate the results of the present findings.

The Effect of Torque Application Technique on Screw Preload of Implant-Supported Prostheses.

To examine the effect of different torque application techniques (torqued, retorqued once, and retorqued twice) on the removal torque of implant-supported fixed complete dental prostheses. Four Nobel Biocare implants (4.3 × 13 + 3; 13-mm thread height + 3-mm collar height) were stabilized temporarily inside four holes made in an acrylic mandibular master model. A metal framework was constructed, casted, and finished using a standardized technique. A passively fitting framework was achieved by removing the implants from the acrylic master model and hand-screwing them to the metal framework. Then, the whole assembly was restabilized in the acrylic master model. The torque experiment consisted of three protocols: (1) torquing screws to 35 Ncm a single time; (2) torquing the screws to 35 Ncm and then immediately retorquing the same screws to the same value; and (3) torquing the same screws to 35 Ncm three consecutive times. Removal torque was recorded for each implant using a digital torque meter. The highest torque value was recorded for the retorqued-once application technique (29.5 ± 1.5 Ncm); next was the torqued technique (27.9 ± 0.7 Ncm); and, last was the retorqued-twice technique (27.2 ± 1.6 Ncm). The Games-Howell post hoc test showed that the retorqued-once application technique resulted in significantly higher torque values than the torqued and retorqued-twice torque application techniques (P ≤ .05). Retightening abutment screws once after the initial torquing could enhance the removal torque of the screw. Care must be taken when retorquing the screws more than once, as this may inversely affect the removal torque.

A histomorphometric study of short and normal implants in human cadavers

Initial implant stability is one of the fundamental criteria for obtaining osseointegration. The aim of this study was to establish a correlation between the primary stability of short and normal implants placed in different types of bone density. A total of 60 Nobel Biocare implants (Goteborg, Sweden®) of different length and design were inserted in 7 maxillae and mandibles of recently deceased persons (20 Replace Select® Straight 10 ´ 4.3 mm, 20 Replace Select® Tapered RP 10 ´ 4.3 mm and 20 Nobelspeedy Shorty® RP 7 ´ 4 mm). Histomorphometry was carried out to analyze the different local bone volume and the bone-to-implant contact (BIC). The mean BIC for the three implant types varied strongly in the maxilla (Replace Select® Straight 0.78% ± 1.0; Replace Select® Tapered 1.3% ± 1.2; Nobelspeedy Shorty® RP 2.35% ± 1.7) but was very similar in the mandible. A comparable pattern was found for the amount of bone tissue present within distances of 0.2 mm and 1.0 mm around the implant. All measured parameters were numerically higher in the mandible than in the maxilla. The fact that shorter implants showed numerically higher values of BIC and BV/TV in the upper jaw, suggests that they may improve implant therapy in cases of poor bone supply in this region. The lack of such differences makes the existence of a similar effect less likely in the lower jaw.

Influence of surface roughness and shape on microdamage of the osseous surface adjacent to titanium dental implants

To assess the relationship between smooth and roughened implant surfaces of straight and narrow configurations with respect to microdamage of the bone surface during placement of dental implants. Straight and tapered, rough and smooth surface Nobel Biocare implants were placed into sheep mandibles. Microdamage within the bone adjacent to the implant surface was quantitated using a semi-automated digitized histomorphometric method. Independent of implant type, microdamage, microcracks, cross-hatch damage and diffuse damage were significantly higher close to the implants compared with far from the implants. Microcracks and cross-hatch damage were higher for the rough cylindrical implants than all the other implant types. Insertion of a rough cylindrical implant type results in an increased fraction of microdamaged bone matrix in comparison to rough tapered, smooth cylindrical and smooth tapered implants.

Bone Level Changes Around Axial and Tilted Implants in Full‐Arch Fixed Immediate Restorations. Interim Results of a Prospective Study

The aim of this prospective study was to assess clinical outcomes and peri-implant bone level changes around tilted and axial implants supporting full-arch fixed immediate rehabilitations up to 60 months of loading. Forty-seven patients (22 women and 25 men) were included in the study. Each patient received a full-arch fixed bridge supported by two axial and two distal tilted implants. Loading was applied within 48 hours of surgery. Patients were scheduled for follow-up at 6, 12, 18, 24 months, and annually up to 5 years. At each follow-up, plaque level and bleeding scores were assessed and radiographic evaluation of marginal bone level change was performed. Periapical radiographs were taken using a paralleling technique, and subsequently scanned at 600 dpi. An image analysis software was used to assess bone level. A total of 33 mandibles and 16 maxillae were rehabilitated (two patients received a fixed prosthesis in both arches). One hundred ninety-six Nobel Biocare implants of 4 mm diameter were placed. The mean follow-up duration was 52.8 months (range 30-66 months) in the mandible, and 33.8 months (range 22-40 months) in the maxilla. All subjects attended the scheduled follow-up visits. No implant was lost. No significant difference in marginal bone loss was found between axial and tilted implants in both jaws, at each follow-up. No significant difference in bone loss was found between mandible and maxilla, for both axial and tilted implants at each comparable time frame, although slightly higher mean values were always found for the mandible. The use of tilted implants in the immediate rehabilitation of fully edentulous jaws is safe and is not associated to a higher marginal bone loss as compared to axially placed implants.

Five‐Year Evaluation of Lifecore Restore® Implants: A Retrospective Comparison with Nobel Biocare MK II® Implants

The purpose of this study was to compare survival rates and marginal bone resorption of the Lifecore (LC) Restore Implant System with the benchmark Nobel Biocare (NB) MK II Implant System. All implants were inserted by the same surgeon and all radiological analyses were performed by the same radiologist. Two hundred ninety LC implants were analyzed radiologically after 1 year and compared with the same number of NB implants serving as a historical reference group. After 5 years, 200 LC implants could be compared with 224 NB implants. Each implant was monitored for exposed threads, as compared with the baseline registrations. No significant differences were found between the two implant systems regarding survival rates (LC 100% and NB 99.2%). Considering the findings of this study, the two implant systems compared might be regarded as clones. Nevertheless, because of dissimilar onset of threads, about 1 mm more implant-retaining bone anchorage is gained with the Lifecore Restore Implants as compared with NB MK II Implants. Based on the assumption that >3 exposed NB threads correspond to >4 exposed LC threads, significantly more bone loss (p < .01) could be demonstrated for the NB implants after 5 years. Thus, it may be justified to consider the differences in implant design to have a decisive clinical relevance.

Immediate Placement of Implants and Appliance in an Irradiated Patient: A Case Study

The purpose of this study was to evaluate the immediate placement of implants and appliance using hyperbaric oxygenation on a 45-year-old male with a history of squamous cell carcinoma of the floor of the mouth. Five Nobel Biocare implants between the mental foamina were used along with a course of pre- and postsurgical hyperbaric oxygenation. After 39 months, the patient is symptom free and shows no signs of rejection. Conclusion Using an accepted hyperbaric oxygenation protocol when placing and restoring immediate implants in this patient resulted in a successful treatment outcome.

Oxidized titanium implants (Nobel Biocare® TiUnite™) compared with turned titanium implants (Nobel Biocare® mark III™) with respect to implant failure in a group of consecutive patients treated with early functional loading and two‐stage protocol

The purpose of this study was to compare two implant types of similar shape but with different surfaces with respect to implant failure. A total of 136 patients were treated with Nobel Biocare Implants between January 2001 and December 2002. Totally 394 implants were placed, of which 199 were oxidized titanium implants (Nobel Biocare TiUnite and 195 with turned titanium surface (Nobel Biocare Mark III. Sixty-three patients underwent a one-stage surgical protocol, of which 24 were objected to early functional loading. The remaining 73 patients were treated with a traditional two-stage surgical protocol. All patients were followed for a minimum of 5 months after loading of the implants. Implants were classified as survivals when clinically stable and fulfilling purported function without any discomfort to the patient, with no signs of infection or ongoing pathologic process. Seven implants were lost in five patients (two males and three females), six in the maxilla and one in the mandible. All failed implants were Mark III implants, inserted following the traditional two-stage protocol. The implant success rate was 98.2% for the whole-patient group, divided as a 100% success rate following the implants with oxidized surface (Nobel Biocare TiUnite compared with a success rate of 96.4% with implants with turned surface (Nobel Biocare Mark III).

Maintenance requirements of implant-supported fixed prostheses opposed by implant-supported fixed prostheses, natural teeth, or complete dentures: A 5-year retrospective study.

Purpose The purpose of this study was to compare the maintenance requirements of implant-supported fixed prostheses with cantilever arms in edentulous jaws when opposed by fixed prostheses of similar design, by natural teeth, or by complete dentures. Materials and Methods The maintenance requirements for the 5-year follow-up period were obtained by examining the dental records of 37 people. Six were provided with fixed prostheses in both arches, 22 with a fixed prosthesis in the mandible opposed by a complete denture, and 9 with a fixed prosthesis opposed by natural teeth. Everyone was treated with Nobel Biocare implants using standard implant and prosthetic protocols. Results The denture teeth and acrylic resin were repaired on 44 occasions in the group with implants in both jaws, on 14 occasions in the group with implants opposed by natural teeth, and twice in the group in which the implants were opposed by a complete denture. The group with implants in both jaws was more likely to fracture the gold-alloy framework, which occurred on six occasions. The group with implants in both jaws was significantly different from the other two groups in relation to higher incidence of fracture of the teeth and gold-alloy framework. Conclusion The maintenance requirements of implant-supported fixed prostheses with cantilever arms opposed by fixed prostheses of similar design were much greater than when opposed by natural teeth or complete dentures.

Examination of the implant—abutment interface after fatigue testing

Purpose. This study examined potential differences in detorque values of abutment screws after fatigue testing when the dimensions between external implant hexagon and internal abutment hexagon were altered or the implant external hexagonal shape was eliminated. Material and Methods. Three subsets (N = 10) of NobelBiocare implants were assessed: (1) standard external hexagon (R), (2) modified hexagon (M), and (3) circular (C) platform geometry. Thirty Procera machined abutments with 25-degree angulated loading platforms were manufactured. Abutments were retained with gold Unigrip abutment screws tightened to 32 N/cm with an electronic torque controller. Vertical scribes across the implant—abutment interface allowed longitudinal displacement evaluation. A carousel-type fatigue testing device delivered dynamic loading forces between 20 and 200 N for 5,000,000 cycles, or the approximate equivalent of 5 years in vivo mastication, through a piston to the abutment platform. Macroscopic and radiographic examination of the implant/abutment specimens was performed. The abutment screws were removed and the detorque values recorded. Bearing surfaces were examined microscopically. Results. No abutment looseness or longitudinal displacements at the implant—abutment interface were noted. Radiographic examination demonstrated no indication of screw bending or displacement. The mean detorque values for R, M, and C were 14.40 ± 1.84 N/cm, 14.70 ± 1.89 N/cm, and 16.40 ± 2.17 N/cm, respectively. The analysis of variance demonstrated significant differences between only designs R and C (P=.031). Conclusion. Increasing the vertical height, or degree of fit tolerance, between the implant external hexagon and the abutment internal hexagon or completely eliminating the implant external hexagon did not produce a significant effect on the detorque values of the abutment screws after 5,000,000 cycles in fatigue testing, or the equivalent of 5 years' of mastication for the implant/abutment specimens evaluated. (J Prosthet Dent 2001;85:268-75.)

The fit of cast and premachined implant abutments

Statement of problem. There is insufficient information regarding the adaptation of abutments to implants. Purpose. This study assessed the adaptation of premachined, cast, and laboratory modified premachined abutments to implants at two sites: abutment/implant interface and screw to screw seat. Material and methods. Six combinations of abutments and implants were studied: CeraOne abutments joined to Nobel Biocare implants; STR (Implant Innovations Inc.) abutments joined to 3I implants; Cast UCLA (3I) abutments subjected to porcelain firing cyclesand joined to 3I implants; Cast UCLA abutments subjected to porcelain firing cycles and joined to Nobel Biocare implants; UCLA premachined abutments cast with gold palladium alloy and subjected to porcelain firing cycles (later joined to 3I implants); and UCLA premachined abutments joined to 3I implants. Each group contained five assemblies. Results. The adaptation of abutments to implants was closer and the amounts of contact larger for assemblies with premachined and laboratory modified premachined abutments than for those with cast abutments. Conclusion. The finishing of custom-made abutments requires further refinement. (J Prosthet Dent 1998;80:184-92.)