Implant Stability Parameters Research Articles

Osseointegration Potential Assessment of Bone Graft Materials Loaded with Mesenchymal Stem Cells in Peri-Implant Bone Defects.

Many studies have been exploring the use of bone graft materials (BGMs) and mesenchymal stem cells in bone defect reconstruction. However, the regeneration potential of Algipore (highly purified hydroxyapatite) and Biphasic (hydroxyapatite/beta-tricalcium phosphate) BGMs combined with bone marrow-derived mesenchymal stem cells (BMSCs) remains unclear. Therefore, we evaluated their osseointegration capacities in reconstructing peri-implant bone defects. The cellular characteristics of BMSCs and the material properties of Algipore and Biphasic were assessed in vitro. Four experimental groups-Algipore, Biphasic, Algipore+BMSCs, and Biphasic+BMSCs-were designed in a rabbit tibia peri-implant defect model. Implant stability parameters were measured. After 4 and 8 weeks of healing, all samples were evaluated using micro-CT, histological, and histomorphometric analysis. In the energy-dispersive X-ray spectroscopy experiment, the Ca/P ratio was higher for Algipore (1.67) than for Biphasic (1.44). The ISQ values continuously increased, and the PTV values gradually decreased for all groups during the healing period. Both Algipore and Biphasic BGM promoted new bone regeneration. Higher implant stability and bone volume density were observed when Algipore and Biphasic BGMs were combined with BMSCs. Biphasic BGM exhibited a faster degradation rate than Algipore BGM. Notably, after eight weeks of healing, Algipore with BSMCs showed more bone-implant contact than Biphasic alone (p < 0.05). Both Algipore and Biphasic are efficient in reconstructing peri-implant bone defects. In addition, Algipore BGM incorporation with BSMCs displayed the best performance in enhancing implant stability and osseointegration potential.

The Effect of Bone Density Measured by Cone Beam Computed Tomography and Implant Dimensions on the Stability of Dental Implants.

The aim of this study was to evaluate the effect of bone density value in Hounsfield unit derived from cone beam computed tomography (CBCT), and implant dimensions in relation to implant stability parameters namely the resonance frequency analysis and the insertion torque (IT) value. It included 24 patients who received 42 dental implants (DI). The bone density of the planned implant site was preoperatively measured using cone beam computed tomography. The implant stability was measured using Osstell implant stability quotient (ISQ). The ISQ values were recorded immediately postoperatively and after 16 weeks. The IT value was categorized as 35 N/cm or > 35 N/cm. The mean (standard deviation) primary stability was 79.58 (5.27) ISQ, which was significantly higher than the secondary stability 74.31 (6.34) ISQ ( P < 0.0001). There was a significant moderate positive correlation of bone density with primary stability ( r = 0.4, P = 0.0099) and no correlation with secondary stability ( r = 0.003, P = 0.9867). The bone density of DI with 35 N/cm IT was significantly lower than with > 35 N/cm IT ( P = 0.0390). Better stability was recorded with wider implants. Whereas the length of the DI showed a nonsignificant correlation with primary and secondary stability ( P = 0.7633 and 0.4670, respectively). The DI dimensions showed a nonsignificant correlation with the IT. Cone beam computed tomography may be considered as a reliable method to assess bone density and predict the implant stability. The diameter of DI affected the implant stability favorably, whereas DI length showed no effect.

Assessment of the Effect of Bone Density on Implant Stability: A Clinical Study.

Background:In this study, we determined the effect of bone density on implant stability.Methodology:Two hundred and sixty dental implant sites in 128 patients were assessed for resonance frequency analysis (RFA) following implant insertion, at 6 months and 12 months. The implant stability quotient (ISQ) was determined.Results:The mean ± standard deviation bone density in anterior mandible was 862.8 ± 203.4 Hounsfield units (HU), in posterior mandible was 528.4 ± 115.6 HU, in anterior maxilla was 594.2 ± 95.2 HU, and in posterior maxilla was 438.1 ± 110.2 HU. The mean insertion torque in successful implants was 38.2 ± 7.1 Ncm and in failed implants was 22.4 ± 4.2 Ncm. The mean RFA value in successful implants was 65.4 ± 5.8 and in failed implants was 45.8 ± 4.1 ISQ. A statistically significant (P < 0.05) difference was obtained.Conclusion:Within the limitation of the study, we observed that successful implants exhibited higher RFA and insertion torque and were higher into failed implants suggesting a correlation of bone quality and implant stability parameters.

Thermoplastic versus Conventional Heat Cured Denture Bases for Implant - Retained Mandibular Overdenture

Objective: The aim of this study was to compare radiographically thermoplastic and conventional heat cured acrylic resin as denture base material for mandibular conventional type implant retained complete overdentures and evaluate the effect of this difference on the implants stability. Materials and methods: Fourteen edentulous patients were selected to construct two implants retained mandibular overdenture. The patients were equally divided into two groups according to material of denture base: group I, patients with thermoplastic resin constructed by injection moulding technique; and group II, patients with denture bases constructed by conventional heat curing acrylic resin. Radiographic and implant stability parameters were evaluated 1 year study. Results: There was no statistically significant difference between the thermoplastic and conventional heat cured denture bases for implant retained mandibular overdenture in bone resorption and stability of the implants. Conclusion: There was no statistically significant difference between the thermoplastic and conventional heat cured implant overdenture bases. Both denture bases have beneficial effect on implant osseointegration and stability.

Modified surgical drilling protocols influence osseointegration performance and predict value of implant stability parameters during implant healing process.

The aim of this study was to evaluate the effects of three different surgical drilling protocols on changes of implant stability parameters and osseointegration performance during the healing period in rabbit femoral condyles. Thirty New Zealand white rabbits were used in this study. Three experimental groups according to different surgical drilling protocols (undersized, standard and oversized preparation) were designed. Measurements of implant stability parameters were performed immediately after implant insertion and then at 1, 2, 4, and 8weeks after the operation. After the animals were sacrificed, the bone blocks with implant were prepared for histological evaluation and histomorphometric analysis. The results demonstrated that the ISQ values of each group increased gradually through the whole healing period, while the damping factor showed the opposite tendency. The histomorphometric analysis revealed that BIC (bone-implant contact) values gradually increased with time until 8weeks of healing at each group. In addition, the undersized group has the highest initial BIC (25.16% ± 7.25%) and the lowest values were found in oversized group (9.13% ± 5.89%). Moreover, a higher correlation (R2= 0. 9817) between ISQ and BIC values in oversized group and moderate correlations between DF and BIC values in undersized group (R2= 0.823) were demonstrated. The undersized drilling protocol group presented the highest implant stability and BIC values in the whole healing period, while the similar tendency of results was found between standard and oversized drilling protocol groups. These results suggested that undersized drilling protocol is mechanically and biologically beneficial in low-density bone. The modifications of surgical drilling protocols would influence the predictive value of implant stability parameters for osseointegration performance.

Implant Stability Parameters &amp; Bone Density Values of Different Graft Materials with Immediately Placed Dental Implants

Objectives: This study was conducted to assess and compare the effect of autogenous bonegraft versus mineralized plasmatic matrix (MPM) and versus the Nano hydroxyapatite bone graftas bone regenerative materials during immediate implant placement.Material and Methods: A total of 14 patients with 18 implants have been included in thisstudy, patients were divided into 3 groups. Group I(control group) received autogenous bone graft.Group II (study group A) received Mineralized Plasmatic Matrix (MPM), and group III (studygroup B) received Nano hydroxyapatite as bone regenerative materials for immediate implantplacement. The treatment outcome was evaluated clinically and radiographically at 3 and 6 monthsof implant placement. Implants stability was measured using Osstell radiofrequency device at 3 and6 months postoperatively. Also bone density were measured radiographically at 2 weeks and at 3and 6 months postoperatively and statistically analysed.Results: Statistical analysis of bone density measurements between the three groups showedsignificant difference (P ≤ 0.05) between the control autogenous bone group and the two othergroups (MPM &Nano bone) at all time intervals. Comparison between the test groups revealednon-significant difference (P ≤ 0.05) between (MPM & Nano bone) at two weeks interval. Whileat three & six months postoperatively there was a significant difference (P ≤ 0.05 between the twogroups. Regarding implant stability comparison between the three groups , there was no statisticalsignificant difference between them (P ≤ 0.05) at three and six months post operatively.Conclusion: The autogenous bone graft remains the gold standard for grafting materials but theuse of MPM and Nano hydroxyapatite grafting materials can also give successful results regardingimplant stability and bone density.

The influence of bone graft procedures on primary stability and bone change of implants placed in fresh extraction sockets

BackgroundThis study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically.MethodsTwenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients.ResultsThe increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg (R = 0.606, P = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery.ConclusionsBone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

Monitoring the Changes of Material Properties at Bone-Implant Interface during the Healing Process In Vivo: A Viscoelastic Investigation.

The aim of this study was to monitor the changes of viscoelastic properties at bone-implant interface via resonance frequency analysis (RFA) and the Periotest device during the healing process in an experimental rabbit model. Twenty-four dental implants were inserted into the femoral condyles of rabbits. The animals were sacrificed immediately after implant installation or on day 14, 28, or 56 after surgery. Viscoelastic properties at bone-implant interface were evaluated by measuring the implant stability quotient (ISQ) using RFA and by measuring the Periotest values (PTVs) using the Periotest device. The bone/implant specimens were evaluated histopathologically and histomorphometrically to determine the degree of osseointegration (BIC%). The BIC% values at different time points were then compared with the corresponding ISQ values and PTVs. The mean ISQ value increased gradually and reached 81 ± 1.7 on day 56, whereas the mean PTV decreased over time, finally reaching −0.7 ± 0.5 on day 56. Significant correlations were found between ISQ and BIC% (r = 0.701, p < 0.001), PTV and BIC% (r = −0.637, p < 0.05), and ISQ and PTV (r = −0.68, p < 0.05). These results show that there is a positive correlation between implant stability parameters and peri-implant-bone healing, indicating that the RFA and Periotest are useful for measuring changes of viscoelastic properties at bone-implant interface and are reliable for indirectly predicting the degree of osseointegration.

The stability analysis of implants installed in osteotomies with different types of controlled bone defects

The stability parameters of implants (ITV, ISQ & PTV) according to different sizes of controlled bone defects made in implant osteotomies were analyzed and the correlation among the three kinds of implant stability parameters was tested in this study. 45 tapped screw-type dental implants were inserted in three types of implant osteotomies made in 8 fresh-frozen pig femoral bones: Type1 — without coronal bone defect, Type2 — with 3 mm coronal bone defects, and Type3 — with 6 mm coronal bone defects. The insertion torque values, ISQ & PTV of implants were measured and analyzed statistically. It is concluded that the circumferential coronal bone defects statistically influence the primary stability of implants; ITV, ISQ and PTV are suitable and available to detect the peri-implant coronal bone defects in 3 mm increments, and ITV and PTV are more sensitive to coronal cortical bone loss. There was a strong correlation between ITV and ISQ.

Effect of a Modified Stepped Osteotomy on the Primary Stability of Dental Implants in Low-Density Bone: A Cadaver Study

The aim of this study was to examine the effect of an alternative surgical technique on endosseous dental implant stability parameters in Class D4 bone. Differences between insertion torque (IT) and implant stability quotient (ISQ) produced by a conventional osteotomy versus a modified stepped osteotomy were examined. Correlations between IT, density in Hounsfield units (HU), and ISQ were also examined. Computed tomographic scans were taken of 16 cadaver heads to determine bone density at maxillary implant recipient sites, which ranged from 173.4 to 312.1 HU. Twenty-two implants were placed in sites with Misch Class D4 bone; control sites received 11 conventional osteotomies and test sites 11 modified stepped osteotomies. Maximum IT was recorded with an implant motor and confirmed with a torque driver, and ISQs were measured. Significant differences were analyzed with a Wilcoxon signed rank test, and correlations were analyzed with the Pearson test. The mean IT in the control group was 15.91 Ncm, and in the test group it was 26.82 Ncm. The modified stepped osteotomy had a significantly greater mean IT than the conventional osteotomy, but no significant difference in ISQ was found between groups. Pearson correlations showed a significant positive correlation between IT in the control and test groups. Significant correlations were found between ISQ and HU in the test group. No other significant correlations between HU, IT, and ISQ were found. Within the limits of this cadaver study, the modified stepped osteotomy resulted in significantly greater implant stability in terms of IT than the conventional osteotomy in soft bone. Significant correlations were found between the IT produced in the modified stepped osteotomy and bone density. No significant correlations were found between IT and ISQ.

Evaluation of relationship between preoperative bone density values derived from cone beam computed tomography and implant stability parameters: a clinical study

The aim of this study was to explore the efficacy of bone density value derived from cone beam computed tomography (CBCT) by evaluating its correlation with implant stability parameters including insertion torque value (ITV) and radiofrequency analysis in relation to different clinical variables including location, gender, age, bone quality, and implant diameter. A total of 65 implants were placed in 17 patients. The bone densities of implant recipient sites were preoperatively recorded using CBCT. Bone quality was subjectively assessed, which depends on the stiffness of the jawbone according to the Lekholm and Zarb index during drilling procedure. The maximum ITV of each implant was recorded using a digital torque meter during implant placement. Resonance frequency measurements were taken using an Osstell Mentor immediately after implant placement. Data were analyzed statistically. The mean bone density, insertion torque, and implant stability quotient values of all implants were 556 ± 80, 37.4 ± 3.3 Ncm, and 73.8 ± 7.2, respectively. Statistically significant correlations were found between bone density values from CBCT and implant stability parameters in relation to all variables. Bone density assessment using CBCT is an efficient method and significantly correlated with implant stability parameters and Lekholm and Zarb index. Thus, it is possible to predict initial implant stability and possibility of immediate or early loading using CBCT scans prior to implant placement.

Relation between bone quality values from ultrasound transmission velocity and implant stability parameters - an ex vivo study

The objective of this study was to determine the relationship between bone qualities measured by ultrasound transmission velocity (UTV) and primary implant stability parameters measured by radiofrequency analysis (RFA) and push-out test (POT) in an ex-vivo model. Three blocks of fresh porcine bone samples were obtained from different anatomic regions, correlating to cortical, mixed and cancellous bone. Mechanical bone qualities of these samples were measured using UTV (expressed in m/s) prior to implantation. Three similar implants (4.1×11mm, AstraTech OS) were inserted into each of the procured bone blocks. The evaluation of implant-bone interface stability was evaluated by RFA expressed as implant stability quotient (ISQ), and POT measured in Newton (N). For cortical, mixed and cancellous bone samples UTV values showed a mean of 2049.33, 1728.67 and 1427.67m/s, respectively. For the implants inserted into cortical, mixed and cancellous bone samples the mean RFA (ISQ) values were 94.33, 81.33 and 63.11, whereas the POT values were >2000, 680 and 290N, respectively. There was a strong correlation between UTV values and implant stability parameters that was shown descriptively by scatter box plots. The bone quality measurements obtained by UTV values significantly correlated to primary implant stability values measured by RFA and push-out test. Moreover, UTV was able to significantly differentiate between the different bone types. This suggested that UTV may be considered as a reasonable instrument to measure bone quality preoperatively and would help clinicians predict primary implant stability before implant insertion.

Biomechanical Aspects of Primary Implant Stability: A Human Cadaver Study

The quality of bone is an important factor in the successful implant treatment, and it is evident that higher implant failure is more likely in poor quality of bone. The primary stability of oral implants related to resistance to micromotion during healing is influenced by bone quality, surgical technique, and implant design. The aims of this biomechanical study were to explore the effect of bone quality on initial intraosseous stability of implants, and to determine the correlations between the bone quality and implant stability parameters. Twenty-four implants (Neoss Ltd., Mölnlycke, Sweden) were placed into anterior and posterior regions of three human cadaver mandibles. The bone densities of implant recipient sites were preoperatively determined using computerized tomography (CT) in Hounsfield unit (HU). The maximum insertion torque values were recorded, and primary implant stability measurements were noninvasively performed by means of resonance frequency analysis (RFA). The bone density values ranged from -267 HU to 553 HU. It was found that mean bone density, insertion torque, and RFA values were 113 +/- 270 HU, 41.9 +/- 5 Ncm, and 70 +/- 7 implant stability quotient (ISQ), respectively. Statistically significant correlations were found between bone density and insertion torque values (r = 0.690, p < .001); bone density and ISQ values (r = 0.557, p < .05); and insertion torque and ISQ values (r = 0.853, p < .001). CT is a useful tool to assess bone quantity and quality in implant recipient sites, and bone density has a prevailing effect on implant stability at placement.

Influence of bone density on implant stability parameters and implant success: a retrospective clinical study

BackgroundThe aim of the present clinical study was to determine the local bone density in dental implant recipient sites using computerized tomography (CT) and to investigate the influence of local bone density on implant stability parameters and implant success.MethodsA total of 300 implants were placed in 111 patients between 2003 and 2005. The bone density in each implant recipient site was determined using CT. Insertion torque and resonance frequency analysis were used as implant stability parameters. The peak insertion torque values were recorded with OsseoCare machine. The resonance frequency analysis measurements were performed with Osstell instrument immediately after implant placement, 6, and 12 months later.ResultsOf 300 implants placed, 20 were lost, meaning a survival rate of %. 93.3 after three years (average 3.7 ± 0.7 years). The mean bone density, insertion torque and RFA recordings of all 300 implants were 620 ± 251 HU, 36.1 ± 8 Ncm, and 65.7 ± 9 ISQ at implant placement respectively; which indicated statistically significant correlations between bone density and insertion torque values (p < 0.001), bone density and ISQ values (p < 0.001), and insertion torque and ISQ values (p < 0.001). The mean bone density, insertion torque and RFA values were 645 ± 240 HU, 37.2 ± 7 Ncm, and 67.1 ± 7 ISQ for 280 successful implants at implant placement, while corresponding values were 267 ± 47 HU, 21.8 ± 4 Ncm, and 46.5 ± 4 ISQ for 20 failed implants; which indicated statistically significant differences for each parameter (p < 0.001).ConclusionCT is a useful tool to determine the bone density in the implant recipient sites, and the local bone density has a prevailing influence on primary implant stability, which is an important determinant for implant success.

Relations between the bone density values from computerized tomography, and implant stability parameters: a clinical study of 230 regular platform implants

The objective of this study was to determine the relationship between bone density, insertion torque, and implant stability at implant placement. One-hundred and eight patients were treated with 230 Brånemark System implants. A computerized tomography (CT) machine was used for pre-operative evaluation of the jaw bone for each patient. The maximum insertion torque values were recorded with the OsseoCare equipment. Implant stability measurements were performed with the Osstell machine for only 142 implants. The mean bone density and insertion torque values were 721+/-254 Hounsfield unit (HU) and 39.1+/-7 N cm for 230 implants, and the correlation was significant (r=0.664, p<0.001). The mean bone density, insertion torque, and resonance frequency analysis values were 751+/-257 HU, 39.4+/-7 Nc m, and 70.5+/-7 implant stability quotient (ISQ), respectively, for 142 implants. Statistically significant correlations were found between bone density and insertion torque values (p<0.001); bone density and ISQ values (p<0.001); and insertion torque and ISQ values (p<0.001). The bone density values from pre-operative CT examination may provide an objective assessment of bone quality, and significant correlations between bone density and implant stability parameters may help clinicians to predict primary stability before implant insertion.