BioHorizons has supported many studies over the years to guide implant and prosthetic development. The scientific method was followed using a wide variety of models including laboratory, animal and human. Within these models, implant performance was evaluated in many different conditions with special emphasis on load analysis including non-functional and functional immediate load as well as early and delayed load.
© Clin. Oral Impl. Res. 2008 May;19(6):553-559.
Purpose:
The different implant systems available today present several types of surface treatments, with the aim of optimizing bone-implant contact. This study compared 4 different types of implant surfaces.
Materials and Methods:
The first, second, third, and fourth mandibular premolars were extracted from five young, adult mongrel male dogs. Ninety days after removal, four 3.75-mm-diameter, 10-mm-long screw-type implants (Paragon) were placed with different surface treatments in mandibular hemiarches. The dogs received two implants of each of the following surface treatments: smooth (machined), titanium plasma spray (TPS), hydroxylapitite coating (HA) and sandblasting with soluble particles (SBM).
The implants were maintained unloaded for ninety days. After this period, the animals were sacrificed, and the hemimandibles were extracted and histologically processed to obtain non-decalcified sections. Two longitudinal ground sections were made for each implant and analyzed under light microscopy, coupled to a computerized system for histomorphometry.
Results:
The following means were obtained for bone-implant contact percentage: machined = 41.7%, TPS = 48.9%, HA = 57.9%, and SBM = 68.5%.
Discussion:
The means for all treatments that added roughness to the implant surface were numerically superior to the mean found for the machined surface. However, this difference was statistically significant only between groups SBM and machined (Tukey test, P < .05).
Conclusions:
The SBM-treated surface provided a greater bone-implant contact that a machined surface after 90 days without loading in this model.
© Int J Oral and Maxillofac Implants 2002;17:377-383 Note: SBM (Sandblasted with Soluble Particles Medium) is equivalent to RBT (Resorbable Blast Texturing) surface treatment. Both surface treatments are performed by Bio-Coat in Southfield, Michigan.
Background:
Dental implant thread geometry has been proposed as a potential factor affecting implant stability and the percentage of osseointegration. Therefore, the aim of this prospective, randomized, parallel arm study was to evaluate the effects of dental implant thread design on the quality and percent of osseointegration and resistance to reverse torque in the tibia of rabbits.
Methods:
Seventy-two custom-made, screw-shaped, commercially pure titanium implants (3.25 mm diameter x 7 mm length) were placed in the tibiae of 12 white New Zealand rabbits. Each tibia received three implants of varying thread shapes: one with a V-shaped, one with a reverse buttress, and one with a square thread design.
The rabbits were sacrificed following an uneventful healing period of 12 weeks. Implants in the right tibiae underwent histologic and histomorphometric assessments of the bone-to-implant contact (BIC) and the radiographic density of surrounding bone, while implants in the left tibiae were used for reverse-torque testing. Differences between the three thread designs were examined using analysis of variance (ANOVA).
Results:
Data showed that the square thread design implants had significantly more BIC and greater reverse-torque measurements compared to the V-shaped and reverse buttress thread designs, while no differences were found in radiographic bone density assessments.
Conclusion:
These results indicate that the square thread design may be more effective for use in endosseous dental implant systems.
© J Periodontol 2004;75:1233-1241
ABSTRACT
Background:
Immediate loading of dental implants has been introduced as a method of reducing implant treatment time without compromising its prognosis. In this research, the effects of loading time on the amount of bone-to-implant contact and bone formation around dental implants were evaluated histologically.
Methods:
Three months prior to implantation, the lower premolar teeth of 15 dogs were extracted. Three or four dental implants were placed in the healed extraction sites for each dog (N = 48). Dividing the dogs into three groups, the implants were either loaded 48 hours or 1 week later with metallic or prefabricated acrylic crowns or were left unloaded until the time of sacrifice. Three months after implant insertion, the animals were sacrificed and samples were investigated to define the amount of bone-to-implant contact, lamellar and woven bone percentage, and local inflammation of the newly formed bone.
Results:
No significant difference in the observed criteria was reported among the three groups (P >0.05); however, the unloaded group had the highest degree of bone-to-implant contact and the group loaded 48 hours after the primary implant insertion had the least. The prosthesis type had no significant effect on the implant success rate (P>0.05). The lamellar and woven bone percentage of newly formed bone also did not differ in the three groups (P>0.05). One implant from each group failed in this study.
Conclusion:
Loading time does not seem to significantly affect the degree of osseointegration and bone-to-implant contact and the composition of newly formed bone around dental implants.
© J Periodontol. 2006;77(10)1701-1707.
This article reports the five-year results of an independently monitored, prospective, multi-center, clinical trial of a bone quality-based implant design. At six study centers, 495 implants were placed in 151 cases with an average follow-up period of 1.6 years (range 1.0 to 3.6 years), following prosthesis delivery.
The majority of the implants placed were D2 or D3 implants to support fixed partial dentures or implant-supported overdentures. Using strict success criteria, there were three implant failures, resulting in a cumulative 99.5% success rate according to Kaplan-Meier survival analysis.
Radiographic analysis revealed a mean bone loss of 0.06 mm at one year and bone gain of 0.04 mm at two years following prosthesis loading. There were no statistical differences in the results by center, implant type, bone density, area of the mouth, or prosthesis type. The results of this five-year study revealed a high success rate and limited bone loss in all areas of the mouth, independent of bone quality.
© Implant Dent 2002;11:224-234
Purpose:
The objective of this study was to determine changes in interdental papillae, alveolar bone loss, esthetics, and initial healing success when one-piece narrow diameter implants are immediately loaded in limited tooth-to-tooth spacing sites.
Materials and Methods:
31 implants were placed in 17 subjects. Digital photographs were made at each clinical visit to assess soft tissue healing. Interproximal soft tissue fill of the embrasure was assessed with a modified Jemt index. Standardized radiographs were made at baseline (implant placement) and at interim healing (6 and 12 months post-surgery). Radiographic bone height was measured from a consistent landmark on the implant. A one-sided t-test was used to determine statistical differences of bone height.
Results:
One implant had clinical mobility and was removed for an overall survival rate of 96.7%. Mean bone height on the day of placement and restoration was 2.33 ± 0.73mm above the first thread. Mean bone height at 6 and 12 months post restoration was 1.75 ± 0.78; 1.63 ± 0.81mm respectively. There was a statistically significant loss of bone support over the initial six months (0.58mm; p<0.01) with no significant progression thereafter (0.12mm; NS). Complete fill of the papillae was found in 92% of maxillary lateral sites and 60% of mandibular incisor sites.
Discussion and Conclusion:
The use of narrow diameter one-piece immediately loaded implants appears to be an effective prosthetic treatment for areas of limited spacing.
© Int J Oral Maxillofac Implants. 2008 Mar-Apr;23(2):281-288
Background:
The immediate loading treatment concept can be successfully used in implant dentistry. Bone cells migrate onto the implant surface and establish a stable anchorage on the titanium surface. When implants are loaded immediately after surgery, there is a high long-term success rate of the implant-supported reconstruction.
Based on histologic observations from different animal studies, the interface of immediately loaded implants can have a direct bone-to-implant connection without any fibrous tissue formation. Mature bone formation is dependent on the loading period. The aim of this study was to demonstrate a histologic analysis of retrieved, clinically stable immediately loaded implants with different implant designs and surfaces. An objective demonstration of the bone-implant interface was presented for the implant systems used.
Methods:
A total of 29 implants [N. BioHorizons = 6] with different implant designs and surfaces were retrieved from patients who were treated with implants using an immediate loading protocol and fixed immediate restorations placed the same day after surgery. The loading period was between 2 and 10 months. The bone-implant interface was examined histologically and histomorphometrically.
Results:
A high bone-to-implant percentage of 66.8% (±8.9%) [BioHorizons BIC% = 80.6%] was found in the examined retrieved implants. Some marginal bone resorption was observed in the crestal part of the implants.
Conclusion:
According to the present histologic and histomorphometric evaluation of retrieved, clinically stable implants, immediate occlusal loading can present a high level of bone-to-implant contact in humans.
© J Periodontol 2005; 76:1823-1832
Background:
The aim of this study was the evaluation, from a clinical point of view, of implants subjected to immediate functional loading (IFL) and to immediate non-functional loading (INFL) in various anatomical configurations.
Methods:
The study included 152 patients who had given their informed consent. A total of 646 implants [N. BioHorizons = 242] were inserted. The implants were placed in 39 totally edentulous mandibles, 14 edentulous maxillae, 23 edentulous posterior mandibles, 16 edentulous anterior mandibles, 16 edentulous anterior maxillae, and 15 edentulous posterior maxillae. Fifty-eight implants were used to replace single missing teeth. In 65 cases, IFL was carried out for 422 implants. INFL was carried out in 116 cases, (224 implants).
Results:
In the IFL group 6 of 422 implants failed (1.4%) [N. BioHorizons = 0/0%] ; in the INFL group 2 of 224 implants failed (0.9%) [N. BioHorizons = 0/0%]. All the other implants appeared, from clinical and radiographic observations, to have successfully osseointegrated and have been functioning satisfactorily since insertion. All failures were observed in the first few months after implant loading.
Conclusion:
Immediate functional and non-functional loading seems to be a technique that gives satisfactory results in selected cases.
© J Periodontol 2003;74:225-241
Background:
The concept of immediate loading of root-form implants for fixed restorations has received increasing interest over the last 5 years. Several authors have commented on parameters that may influence results, including implant number; implant length, bone density, and patient habits. The trigger for bone remodeling around an implant may occur from the surgical trauma of insertion or the mechanical environment of strain at the interface.
In the classic two-stage approach, these were divided episodes, separated by 3 to 6 months. Immediate loading compresses this time frame; the two driving mechanisms for bone repair occur concurrently. A scientific approach to the interface development is to match the bone healing response of trauma (woven bone of repair) to the response of mechanical load (reactive woven bone), so the sum of these two entities does not result in fibrous tissue formation and clinical mobility of the implant.
Purpose:
It is the purpose of this article to review the scientific rationale of these statements and coordinate them to bone physiology and bone biomechanics.
Materials and Methods: Findings from previous reports in the literature were reviewed and summarized to form the basis of a prospective study using a bone quality-based implant system (Maestro, BioHorizons Implant Systems, Inc., Birmingham, AL, USA).
A transitional prosthesis was delivered either on the day of surgery or within 2 weeks for 30 patients and 31 arches. A total of 244 implants were used to support these restorations, for an average of 7.8 implants per prosthesis. After 4 to 7 months, the final restorations were fabricated. One year after the final restoration was loaded, the implant survival was 100%; the 31 restorations also had a survival of 100% over this time frame. This report presents these implants and restorations over a 1- to 5-year period, with an average follow-up period of 2.6 years.
Results:
The bone loss from implant insertion to final prosthesis delivery averaged 0.7 mm. The first-year bone loss after final prosthesis delivery averaged 0.07 mm. A slight increase in bone height was observed after the first year, but generally no increase was observed over the remaining evaluation period.
Conclusions:
In the current report, no implant failure occurred, and crestal bone loss values were similar to or less than values reported with the conditional two-stage approach. This may be related to the number and position of implants, implant design, and/or the surface condition of the implant loading.
© Clin Implant Dent Relat Res 2003;5:17-28
Immediate loading is a surgical-prosthetic procedure extensively used in implant dentistry. Despite its frequent use, minimal data are available on the long-term clinical success rate of immediate functional loading (IFL) and immediate nonfunctional loading (INFL) of implants. The aim of this study was to evaluate the long-term survival and bone loss of immediate nonfunctional single implant restorations in a group of patients that were monitored for 5 years.
One hundred and eleven patients (41.4% men) with a median age of 40 years were included in this study. A total of 111 implants were placed. All implants were placed with a minimum insertion torque of 25 Ncm. A temporary restoration was relined with acrylic resin, trimmed, polished, and cemented or screw retained 1 to 2 hours later. Occlusal contact was avoided in centric and lateral excursions.
After provisional crown delivery, a periapical radiograph was performed by means of a customized Rinn holder device. Data were analyzed by means of Kaplan-Meier and life-table algorithms. Stratification of implant survival was performed for the available variables of interest, and comparisons were analyzed using a log-rank test.
Investigated parameters were time of implant placement, bone quality, implant site, implant diameter and length, and type of implant surface enhancement. The parameters for overall success rate were defined by bone resorption <1.5 mm after the first year of loading and <0.2 mm thereafter. During the 5-year follow-up period, a survival rate of 95.5% was observed. All failures occurred within 4 months of implant loading.
There were statistically significant differences regarding healed vs. post-extraction implant sites (100% and 92.5%, respectively, P = .05) and type of bone (D1 vs. D4 yielded 100% and 95.5%, respectively, P <.05). No differences were detected for: (1) site (100% for mandible and 94.6% for maxilla, P =.319); (2) implant diameter (survival rates of 97.26% for <4.5-mm diameter and 92.11% for >4.5- mm diameter, P =.206); (3) implant lengths (survival rates of 96.97% for implants >13 mm and 94.87% for implants <13 mm, P=.624); and (4) type of implant surface enhancement (survival rates of 94.03% for 67 cases of grit-blasted and acid-etched surfaces and a failure rate of 4 out of 5, and 94.12% for 17 cases of hydroxyapatite (HA)-coated surfaces with only 1 failure).
The success rate (defined as bone resorption <1.5 mm after the first year of loading and <0.2 mm thereafter) was 97.2%. Immediate nonocclusal loading of single implants is a reliable surgical-prosthetic procedure with a low rate of implant loss and a low quantity of peri-implant bone loss over time.
© J Oral Implantol 2006;32:43-51
Once the titanium bar was welded intraorally to the abutments, opaque was applied and the provisional restoration was relined and screw-retained the same day. In addition, a comparison of deformations and stress distributions in implant-supported, metal-reinforced and nonmetal-reinforced resin provisional restorations was analyzed in the edentulous mandible by a three-dimensional finite element model (FEM).
Results:
All of the 192 rigidly temporized immediately loaded implants osseointegrated. An implant success rate of 100% was achieved over a period of 6 months postplacement. No fracture or luting cement failure of the provisional restoration occurred during the observation time. Compared to mere acrylic superstructures, a significant reduction of deformation and strain within metal-reinforced provisional restorations was detected by FEM analysis.
Conclusion:
The results of this study indicate that the syncrystallization technique allows an expedite and adequate rigid splinting of multiple immediately loaded implants. The advantages of the technique are:
© Clin Implant Dent Relat Res 2006;8:123-134
The maxillary posterior region of the mouth sustains greater bite forces compared to the anterior, yet often presents the poorest bone density. A biomechanical approach, often presented to decrease risk factors in regions of high stress or poor bone density, is to increase implant surface area. Most manufacturers provide implants in variable lengths.
Sinus grafts permit longer implants; however, finite element analysis support the hypothesis that implant length is a secondary parameter for stress distribution. A more beneficial approach, to enhance implant surface area in the posterior regions, has primarily been to increase the implant diameter. However, when conventional designs and diameters are used, this only increases surface area by 30% yet bite forces increase by more than 300% in the posterior regions.
A change in implant diameter and thread design (i.e. BioHorizons Implant System, Inc.) may increase surface area by more than 300%. This clinical report demonstrates an implant surgical success rate of 99.4% in the posterior maxilla, using the bone quality-based implant system from BioHorizons. In addition, there were no early loading failures and no prosthetic failures.
Crestal bone loss during early loading averaged .71 mm or less, dependent upon a one-stage or two-stage surgical approach. The increase in surface area of this design, coupled with the compressive load thread of this design, may indeed be responsible for the decrease in early loading implant failure and also contribute to a decrease in crestal bone stresses, which may reduce crestal bone loss.
© Oral Health 2000;8:7-15
Objectives:
The use of osseointegrated implants as an endoestal anchorage device to provide support for dental prostheses is a reliable and widely accepted treatment modality. The purpose of this study was to evaluate the clinical performance of biohorizons implants placed in the maxilla or in the mandible.
Methods:
One hundred fifty-five consecutive patients (71 men, 84 women), aged between 18 and 72 years (mean: 54 years) participated in this study. A total of 500 implants (internal; BioHorizons, Birmingham, AL, USA) were inserted. The cases were examined retrospectively in order to evaluate the clinical efficiency of BioHorizons implants and to determine the success rate of implant retained/supported prosthesis after a 5-year period. All implants were assessed clinically and radiographically on a yearly basis.
Results:
One hundred fifty-five consecutive patients (71 men, 84 women), aged between 18 and 72 years (mean: 54 years) participated in this study. A total of 500 implants (internal; BioHorizons, Birmingham, AL, USA) were inserted. The cases were examined retrospectively in order to evaluate the clinical efficiency of BioHorizons implants and to determine the success rate of implant retained/supported prosthesis after a 5-year period. All implants were assessed clinically and radiographically on a yearly basis.
Conclusion:
Within the limitations of the observation period and sample number, the present findings confirmed sufficient success and survival rates of BioHorizons implants placed in the mandible as well as implants placed in the maxilla after a 5-year period. We can then conclude these implants can be highly satisfactory from a clinical point of view.
© Ege University, Faculty of Dentistry, Izmir, Turkey