Implant stability measurements using resonance frequency analysis: biological and biomechanical aspects and clinical implications

Evaluation of the Transfemoral Bone-Implant Interface Properties Using Vibration Analysis

Evaluating the bone-implant interface (BII) properties of osseointegrated transfemoral (TFA) implants is important for early failure detection and prescribing loads during rehabilitation. The objective of this work is to derive and validate a 1D finite element (FE) model of the Osseointegrated Prosthetic Limb (OPL) TFA system that can: (1) model its dynamic behaviour and (2) extract the BII properties. The model was validated by: (1) comparing the 1D FE formulation to the analytical and 3D FE solutions for a simplified cylinder, (2) comparing the vibration modes of the actual TFA geometry using 1D and 3D FE models, and (3) evaluating the BII properties for three extreme conditions (LOW, INTERMEDIATE, and HIGH) generated using 3D FE and experimental (where the implant was embedded, using different adhesives, in synthetic femurs) signals for additional validation. The modes predicted by the 1D FE model converged to the analytical and the 3D FE solutions for the cylinder. The 1D model also matched the 3D FE solution with a maximum frequency difference of 2.02% for the TFA geometry. Finally, the 1D model extracted the BII stiffness and the system's damping properties for the three conditions generated using the 3D FE simulations and the experimental INTERMEDIATE and HIGH signals. The agreement between the 1D FE and the 3D FE solutions for the TFA geometry indicates that the 1D model captures the system's dynamic behaviour. Distinguishing between the different BII conditions demonstrates the 1D model's potential use for the non-invasive clinical evaluation of the TFA BII properties.

Evaluation of bone integrity around the acetabular cup using noninvasive laser resonance frequency analysis

Resonance frequency analysis (RFA) is valuable for assessing implant status. In a previous investigation, acetabular cup fixation was assessed using laser RFA and the pull-down force was predicted in an in vitro setting. While the pull-down force alone is sufficient for initial fixation evaluation, it is desirable to evaluate the bone strength of the foundation for subsequent fixation. Diminished bone quality causes micromotion, migration, and protracted osseointegration, consequently elevating susceptibility to periprosthetic fractures and failure of ingrained trabecular bone. Limited research exists on the evaluation of bone mineral density (BMD) around the cup using RFA. For in vivo application of laser RFA, we implemented the sweep pulse excitation method and engineered an innovative laser RFA device having low laser energy and small dimensions. We focused on a specific frequency range (2500-4500 Hz), where the peak frequency was presumed to be influenced by foundational density. Quantitative computed tomography with a phantom was employed to assess periprosthetic BMD. Correlation between the resonance frequency within the designated range and the density around the cup was evaluated both in the laboratory and in vivo using the novel laser RFA device. The Kruskal-Wallis test showed robust correlations in both experiments (laboratory study: R = 0.728, p < 0.001; in vivo study: R = 0.619, p < 0.001). Our laser RFA system can assess the quality of bone surrounding the cup. Laser RFA holds promise in predicting the risk of loosening and might aid in the decision-making process for additional fixation through screw insertion.

Double layer graft technique for horizontal alveolar ridge augmentation with staged implant placement: radiographic histological and implant stability analysis-a case report

INTRODUCTION

Horizontal ridge augmentation of a deficient alveolar bone site is performed either simultaneously with implant placement or in a staged approach prior to implant insertion. There are several available strategies for the augmentation of alveolar ridge deficiencies, including guided bone regeneration (GBR) through the use of barrier membranes. The success of the GBR approach mainly depends on the exclusion of soft tissue cells during bone remodeling.

CASE PRESENTATION

A healthy 25-year-old male patient presented with a missing upper left central incisor after clinical and radiographic examination, the site showed a class III defect horizontal atrophy. The procedure performed was the horizontal alveolar ridge augmentation using resorbable pericardium membrane with double layer graft technique (DLT) where autogenous bone placed as a first layer of the graft followed by xenograft as a second layer, the membrane was fixed with titanium pins. A cone beam computed tomography (CBCT) was performed before, immediately and 6 month following the surgery. After 6 months during implant placement, a core biopsy specimen was retrieved, stored and prepared for histological evaluation, with assessment of primary implant stability. The radiographic analysis showed a horizontal width gain of about 4 mm, at 6 month following implant placement, the implant was successfully osteointegrated with stability assessment also done after 6 months from placement.

CONCLUSION

DLT was successfully used for horizontal alveolar ridge augmentation, thus allowing a prosthetically driven implant placement. More cases assessing implant survival and success are needed to confirm the results of this case report.

Evaluation of a vibration modeling technique for the in-vitro measurement of dental implant stability

The Advanced System for Implant Stability Testing (ASIST) is a device currently being developed to noninvasively measure implant stability by estimating the mechanical stiffness of the bone-implant interface, which is reported as the ASIST Stability Coefficient (ASC). This study's purpose was to determine whether changes in density, bonding, and drilling technique affect the measured vibration of a dental implant, and whether they can be quantified as a change in the estimated BII stiffness. Stability was also measured using RFA, insertion torque (IT) and the pullout test. Bone-level tapered implants (4.1 mm diameter, 10 mm length) were inserted in polyurethane foam as an artificial bone substitute. Samples were prepared using different bone densities (20, 30, 40 PCF), drilling sequences, and superglue to simulate a bonded implant. Measurements were compared across groups at a significance level of 0.05. The ASC was able to indicate changes in each factor as a change in the interfacial stiffness. IT and pullout force values also showed comparable increases. Furthermore, the relative difference in ISQ values between experimental groups was considerably smaller than the ASC. While future work should be done using biological bone and in-vivo systems, the results of this in-vitro study suggest that modelling of the implant system with a vibration-based approach may provide a noninvasive method of assessing the mechanical stability of the implant.

Very Early Loading of a Bone-Anchored Hearing System Is Safe

OBJECTIVE

To investigate the feasibility of early sound processor loading with two separate bone-anchored hearing aid implants 1 to 2 weeks after implantation. Secondary endpoints included registration of any postoperative complications, skin reactions, and any adverse events.

STUDY DESIGN

Prospective, nonrandomized, noncontrolled, multicenter clinical trial.

SETTING

Tertiary referral center.

PATIENTS

Sixty adult patients, eligible for bone-anchored hearing aid surgery, were enrolled.

INTERVENTION

Implantation of the bone-anchored hearing aid implants were done using minimally invasive surgery with tissue preservation.

MAIN OUTCOME MEASURE

Implant stability quotient (ISQ) values were recorded using resonance frequency analysis. Follow-ups were scheduled 5 to 12 days, 4 to 8 weeks, 6 months, and 12 months postoperatively. Differences between the lowest ISQ values (ISQ low) over time were analyzed by paired-samples t test with a significance level of 0.05. Skin and soft tissue reactions were assessed according to Holger's classification.

RESULTS

Loading time of the Ponto Wide implant was 11.6 ± 1.4 days (SD) in average (median, 12 d; range, 7-19 d). Loading of the Ponto BHX implant was done 9.7 ± 3.5 days (SD) postoperatively (median, 9 d; range, 5-19 d). The implant stability increased significantly during the 12-month study period with both implants. One Ponto BHX implant was lost. Skin and soft tissue reactions were few in both groups. Across all planned follow-up visits, no skin and soft tissue reactions were observed in 86% (Ponto BHX implant) and 85% (Ponto Wide implant).

CONCLUSION

Very early loading of sound processors after percutaneous bone-anchored hearing system surgery is safe already 1 to 2 weeks postoperatively.

Resonance frequency analysis for evaluation of the connecting condition between fixed prostheses and their abutment teeth: An in vitro and finite element analysis study

STATEMENT OF PROBLEM

Loss of retention is a clinical complication for fixed partial dentures (FPDs). However, a method sensitive enough to measure the early retention loss of FPDs is lacking.

PURPOSE

The purpose of this in vitro and finite element analysis (FEA) study was to determine whether resonance frequency analysis (RFA) with a newly developed system can detect lack of FPD retention caused by cement loss.

MATERIALS AND METHODS

Two evaluation methods were used: RFA of an in vitro model of a 3-unit FPD from the second premolar to the second molar and FEA by using a simplified model. The in vitro model was used to evaluate 4 connecting conditions: both crowns cemented, only the premolar crown cemented, only the molar crown cemented, and both crowns uncemented. Tapping stimulation (16 impulsive forces, 4 Hz) was directly applied to the buccal side of the second molar or the second premolar, and an attached 3D accelerometer sensor was used to record the resonance frequency (RF) of the tapped tooth. The amplitude, frequency, Q-value, and total area under the curve (AUC) of the RF values in the buccolingual direction were compared between connecting conditions. The FEA was done by using a simplified model of a 3-unit FPD with similar connecting conditions as the in vitro model study, and the RF amplitude and frequency of each tooth were calculated. Statistical evaluation included 1-way analysis of variance and the Tukey HSD test to compare the differences among each connecting condition under each parameter for measurement sites on the molar and the premolar, respectively (α=.05).

RESULTS

For both the molar and premolar measurements in both the in vitro and FEA models, when the measurement site was on the uncemented tooth, the amplitude of RF-1 increased, the Q-value of RF-2 decreased, and the area under the curve increased (P<.05).

CONCLUSIONS

The same 3 trends found between the measurement sites of the in vitro study and FEA indicated that RFA may be useful for detecting an FPD with loosening caused by cement loss, even partial cement loss.

A randomized, multicenter, double-blinded parallel study to evaluate the safety and performance of zoledronate-coated versus uncoated dental implants in partially edentulous patients

OBJECTIVE

To evaluate patient safety, implants survival and implant stability of the bisphosphonate (zoledronate) as a coating on dental implants in patients requiring oral rehabilitation in the posterior maxilla.

MATERIALS AND METHODS

In this multicenter, double-blind, randomized controlled study, 62 patients were randomized to receive either zoledronate-coated or uncoated control implants in the premolar or molar area of the maxilla, using a one stage-protocol. Due to dropouts and exclusion 49 patients completed the study. The implants were examined by resonance frequency analysis (RFA) using an implant stability quotient (ISQ) scale at the time of insertion, and at 8 weeks, and after 12 weeks prior to prosthetic restoration. Radiographs were taken prior to surgery, directly after insertion, and during the follow-up at 12 weeks, 6 months, and 1 year to analyze changes in marginal bone levels (MBL). Finally, all complications and adverse effects (AE) were observed and recorded.

RESULTS

Out of 62 included patients, 49 patients completed the study. No AE were reported by patients receiving zoledronate-coated implants. There was no statistically significant difference between the zoledronate-coated or uncoated implant groups when comparing ISQ levels at insertion and after 12 weeks of healing, the mean of the ISQ values demonstrated a change of 4.64 (95% confidence interval: 15.46; 5.79, p = 0.43) between the two groups. At 8- and 12-weeks, ISQ values remained stable (range 62-70). Radiographic analysis showed no statistically significant difference in MBL between the two implant groups after 1 year of loading neither at the mesial side (p = 0.99) or the distal side (p = 0.97). MBL for coated implants were 0.57 mm at the mesial side and 0.46 mm at the distal side. For the uncoated implants, MBL was 0.48 mm at the mesial side and 0.47 mm at the distal side.

CONCLUSION

The zoledronate-coated dental implants are safe to use in a one-stage surgery protocol in patients requiring oral rehabilitation in the posterior maxilla, after 1 year of loading. There were no statically significant changes in implant stability and marginal bone levels measured by intraoral radiographs in comparison to uncoated control implants.

Radiological Evaluation and Biomechanical Stability of Implants Simultaneously Placed at the Sites with Sole Advanced Platelet-Rich Fibrin (A-PRF) Grafted Sinus Floor

Introduction

In this retrospective study stabilities of 24 implants simultaneously placed at posterior maxillae with sinuses grafted by advanced platelet rich fibrin (A-PRF) and newly formed bone around them were evaluated.

Patient and Methods

Fourteen augmented maxillary sinuses of 11 patients with a mean residual alveolar bone height of 4.55 mm were involved in this study. Maxillary sinus lifting via lateral window approach and implant site osteotomy were performed, and prepared A-PRF clots were used as sole graft material. Each of the implants was immediately placed with a good primary stability. Postoperative sixth month tomography images were compared with preoperative ones in order to calculate the gained bone height and implant stability quotient (ISQ) values were recorded.

Results

The new vertical mean bone height of 24 implant sites was 12.21 mm with an implant survival rate of 100%. ISQ values of the implants were ranging from 62 to 75 with a mean value of 68. Statistically the diameter of implant did not have any effect on new bone formation and the ISQ values, however the length of them did.

Conclusion

A-PRF as a graft material for sinus lifting with simultaneous implant placement is a reliable technique with its low cost and lack of immunogenic reaction risk.

Maxillary sinus membrane elevation and coagulum compared with maxillary sinus floor augmentation and a composite graft: A 1-year single-blinded randomized controlled trial

OBJECTIVE

The aim was to evaluate the 1-year implant outcome and patient-related outcome measures (PROMs) after maxillary sinus membrane elevation and coagulum (test) compared with maxillary sinus floor augmentation and a 1:1 ratio of autogenous bone graft from the buccal antrostomy and deproteinised porcine bone mineral (DPBM) (control).

MATERIALS AND METHODS

Forty patients (30 female, 10 male) with a mean age of 50 years (range 25-71 years) and an alveolar ridge height between 4 and 7 mm were randomly allocated to test or control. Outcome measures included survival of suprastructures and implants, implant stability quotient, health status of the peri-implant tissue, peri-implant marginal bone loss, frequency of complications and PROMs using Oral Health Impact Profile-14 combined with questionnaires assessing patient's perception of the peri-implant soft tissue, implant crown, function of the implant, and total implant treatment outcome using visual analogue scale. Mean differences were expressed with standard deviation and 95% confidence interval. Level of significance was 0.05.

RESULTS

All suprastructures and implants were well-functioning after 1-year of functional implant loading. No significant difference in any of the applied outcome measures was observed between test and control. Both treatments revealed high patient satisfaction scores and significant improvement in oral health-related quality of life.

CONCLUSION

There were no significant differences in implant outcome and PROMs between test and control, after 1-year of functional implant loading. Neither of the treatments can therefore be considered better than the other. Thus, long-term randomized controlled trials are needed before definitive conclusions can be provided about the two treatment modalities.

Development of reduced volume endosseous cuspid tooth implant using topology optimization by SIMP technique for improved osseointegration

The article aims to design and develop a topology-optimized endosseous cuspid tooth implant of the maxilla region. The manuscript presents a numerical analysis of the resulting von Mises stresses and effective strain resulting in the topology-optimized implant with occlusal loading of 110 N. Solid Isotropic Material with Penalization (SIMP) method is employed for topology optimization and four different models, namely model-1, model-2, model-3, and model-4, are developed based on volume reduction rates of 8%, 16%, 24%, and 32%, respectively. FEA results highlight that the maximum stress and strain in the screw increases with volume reduction rates. The comparative analyses of the resulting stresses in the compact and cancellous bone along with the strain in the screw led to the conclusion that model-1, model-2, and model-3 resulted in moderate stresses on compact and cancellous bone compared to the original model of the implant. However, the screw and bones are subjected to maximum stress and strain in the model-4. The study concludes that model-2, with 16% reduced volume and 14.2% reduced mass as compared to the original implant, may be considered as the optimized design of the model. The resulting model offers a significant reduction in the weight and volume with a minor increase in effective stress and strain without negatively impacting the functionality and bio-mechanical performance of the implant. The optimized dental implant prototype is also fabricated as a proof of concept by the Fused Deposition Modelling process.

Evaluation of different surface treated implants after provisionalization: A 6-month prospective study

Background

Replacing missing teeth with dental implants has become the best treatment option; therefore, clinicians need to understand the predictability of the treatment. Surface treatment of implants is one of the methods to improve osseointegration, thus improving the quality of treatment. Increasing esthetic awareness among patients has led to the popularity of immediate provisionalization of dental implants. This study investigated the effect of surface treatment on implant stability when loaded with immediate non-functional temporary prostheses and compared the superiority of one surface treatment over the other in terms of osseointegration by evaluating implant stability quotient (ISQ).

Methods

Twenty implants with different surface treatments were placed, i.e., resorbable blast media (RBM) surface and alumina blasted/acid-etched (AB/AE) surfaces. All the implants were non-functionally loaded, and ISQ was measured immediately after implant placement and 6 and 12 weeks after non-functional loading. Crestal bone levels, mPI, mSBI, and peri-implant probing depths were compared for both groups at 1, 3, and 6 months.

Results

At 12 weeks, all the implants showed desirable ISQ, indicating successful osseointegration. The increase in ISQ at 12 weeks was significantly higher for RBM implants compared to baseline, indicating a more predictable course of osseointegration. Crestal bone levels recorded at 1, 3, and 6 months did not significantly differ between the groups. All other parameters showed comparable values for both groups at all intervals.

Conclusion

Replacing missing teeth with dental implants with immediate non-functional restorations is a predictable treatment option.

Significance of bone morphology and quality on the primary stability of orthodontic mini-implants: in vitro comparison between human bone substitute and artificial bone

AIM

This study evaluated artificial bone models against a human bone substitute to assess the primary stability of orthodontic mini-implants (OMIs) at varying implant sites with different morphologies and qualities.

MATERIALS AND METHODS

A total of 1200 OMI placements of four types were inserted into four artificial bone models of different density (D1, D2, D3, D4) and into a human bone substitute (HB). The implants varied in diameter (2.0 and 2.3 mm) and length (9 and 11 mm). Each specimen had four implant sites: no defect, one-wall defect, three-wall defect, and circular defect. The implant stability quotient (ISQ) values were measured using resonance frequency analysis (RFA) and insertion placement torque values (IPT) were assessed for primary stability. Correlation analysis was performed to evaluate the different models.

RESULTS

The highest IPT value was registered for the 2.0 mm × 11 mm implant inserted into D1 with no defect (37.53 ± 3.02 Ncm). The lowest ISQ value was measured for the 2.3 mm × 9 mm OMI inserted into D3 with a circular defect (12.33 ± 5.88) and the highest for the 2.3 mm × 9 mm implant inserted into HB with no defect (63.23 ± 2.57). A strong correlation (r = 0.64) for IPT values and a very strong correlation (r = 0.8) for ISQ values was found between D2 and HB.

CONCLUSION

Bone defects and bone quality affected the primary stability of implants in terms of ISQ and IPT values. Results for bone model D2 correlated very well with the HB substitution material.

Bone density and proximal support effects on dental implant stability - Finite element analysis and in vitro experiments

OBJECTIVES

The application of dental implants presents the occurrence of implant failures associated with bone proximal support. This study aims to assess implant behavior, in particular implant stability and strain distribution in the bone at different bone densities, and the effect of proximal bone support.

MATERIAL AND METHODS

Three bone densities (D20, D15, and D10) were considered in the experimental in vitro study, represented by solid rigid polyurethane foam and two conditions of bone support in the proximal region. A finite element model was developed and validated experimentally and a Branemark model at a 3:1 scale was implanted in the experiments; the model was loaded and extracted.

RESULTS

The results of the experimental models validate the finite element models with a correlation R2 equal to 0.899 and NMSE of 7%. The implant extraction tests for the effect of bone properties in the maximum load were 2832 N for D20 and 792 N for D10. The effect of proximal bone support changes the implant stability was observed experimentally; at 1 mm less bone support decreases by 20% of stability and at 2 mm by 58% for D15 density.

CONCLUSIONS

Bone properties and bone quantity are important for the initial stability of the implant. A bone volume fraction of less than 24 g/cm3 exhibits poor behavior and is not indicated for implantation. Proximal bone support reduces the primary stability of the implant and the effect is critical in lower bone density.

Influence of Implant Macro-Design, -Length, and -Diameter on Primary Implant Stability Depending on Different Bone Qualities Using Standard Drilling Protocols-An In Vitro Analysis

(1) Background: Primary implant stability is vital for successful implant therapy. This study explores the influence of implant shape, length, and diameter on primary stability in different bone qualities. (2) Methods: Three implant systems (two parallel-walled and one tapered) with various lengths and diameters were inserted into polyurethane foam blocks of different densities (35, 25, 15, and 10 PCF) using standard drilling protocols. Primary stability was assessed through insertion torque (IT) and resonance frequency analysis (RFA). Optimal ranges were defined for IT (25 to 50 Ncm) and RFA (ISQ 60 to 80). A comparison of implant groups was conducted to determine adherence to the optimal ranges. (3) Results: Implant macro-design, -length, and -diameter and bone block density significantly influenced IT and RFA. Optimal IT was observed in 8/40 and 9/40 groups for the parallel-walled implants, while the tapered implant achieved optimal IT in 13/40 groups (within a 25-50 Ncm range). Implant diameter strongly impacted primary stability, with sufficient stability achieved in only one-third of cases despite the tapered implant's superiority. (4) Conclusions: The findings highlight the need to adapt the drilling protocol based on diverse bone qualities in clinical practice. Further investigations should explore the impact of these adapted protocols on implant outcomes.

Combination of leukocyte and platelet-rich fibrin and demineralized bovine bone graft enhanced bone formation and healing after maxillary sinus augmentation: a randomized clinical trial

BACKGROUND AND OBJECTIVE

The resorption of alveolar ridge bone and maxillary sinus pneumatization are challenges to implant-supported prosthetic rehabilitation. Bone regeneration using bone substitutes and growth factors are alternatives for maxillary sinus augmentation (MSA). Therefore, we sought to evaluate the effects of the association between leukocyte and platelet-rich fibrin (L-PRF) and deproteinized bovine bone mineral (DBBM) in MSA procedures.

MATERIALS AND METHODS

Thirty-six maxillary sinuses from 24 individuals were included in this randomized clinical trial. The maxillary sinuses were randomly grafted with LPRF and DBBM (test group) or grafted only with DBBM (positive control). Dental implants were installed in the test group following two periods of evaluation: after 4 (DBBM+LPRF4) and 8 (DBBM+LPFR8) months of sinus graft healing, while the control group received implants only after 8 months. Cone beam computed tomography (CBCT) was taken 1 week after surgery (T1) and before implant placement (T2). Bone samples were collected during implant placement for histomorphometric and immunohistochemical (IHC) analysis. The primary implant stability was assessed by resonance frequency analysis.

RESULTS

CBCT analysis demonstrated a significant decrease in bone volume from T1 to T2 in all groups without differences among them. Histologically, the test group showed significantly increase in bone neoformation in both periods of evaluation (LPRF+DBBM4: 44.70±14.01%; LPRF+DBBM8: 46.56±12.25%) compared to the control group (32.34±9.49%). The control group showed the highest percentage of residual graft. IHC analysis showed increased staining intensity of osteocalcin (OCN), vascular endothelial growth factor (VEGF), and runt related transcription factor 2 (RUNX-2) in LPRF+DBBM4 group, and osteopontin (OPN) in the L-PRF+DBBM8. Primary implant stability was successfully achieved (above 60 in implant stability quotient) in all the evaluated groups.

CONCLUSION

Combination of L-PRF and DBBM increased and accelerated new bone formation allowing early implant placement probably due to the higher protein expression of RUNX2, VEGF, OCN, and OPN. These data suggest that the use of L-PRF might be an interesting alternative to use in combination with DBBM for augment the maxillary sinuses allowing the installation of appropriate length implants in shorter period of time.

CLINICAL RELEVANCE

This study showed improvement in bone neoformation and accelerated healing when associating L-PRF and DBBM for maxillary sinus augmentation procedures.

TRIAL REGISTRATION

This study was registered before participant recruitment in Brazilian Registry of Clinical Trials (ReBEC - RBR-95m73t).

Significance of 25(OH) D3 in Early Dental Implant Failure (EDIF) during osseointegration-A systematic review

Bone metabolism is a key factor for successful osseointegration, and low vitamin D levels may negatively impact the process of osseointegration after implant placement. The study was aimed at evaluating the relation of vitamin D levels with dental implant osseointegration and subsequently the success or failure of the implant. The focused questions were-What is the effect of vitamin D levels on successful dental implant osseointegration and what is the effect of vitamin D supplementation on successful implant osseointegration? A search was conducted on PubMed and Google Scholar using the terms "vitamin D," "cholecalciferol," "1,25(OH) D," "dental implant," "osseointegration," and "bone implant contact" for a period of 10 years from 2011 to 2020. Clinical trials, cross-sectional studies, case series, and case reports were included. A total of ten studies were included after the screening process. Five of these studies evaluated the effect of vitamin D supplementation on osseointegration, whereas five only evaluated the effect of vitamin D deficiency on dental implant osseointegration. Only five of these studies reported dental implant failure varying from 7% to 13% in vitamin D deficient/insufficient groups. Positive relationship exists between serum vitamin D levels and dental implant osseointegration; however, few studies failed to report any relation. More prospective clinical research studies as well as randomized controlled trials are needed to show a significant correlation between decreased serum levels of vitamin D and increased risk of dental implant failure in perspective of vitamin D supplementation which can promote the osseointegration of dental implants.

Investigation of the Influence of Roughness and Dental Implant Design on Primary Stability via Analysis of Insertion Torque and Implant Stability Quotient: An In Vitro Study

In the placement of dental implants, the primary fixation between the dental implant and the bone is of great importance and corresponds to compressive mechanical fixation that aims to prevent micromovement of the implant. The aim of this research was to determine the role of roughness and the type of dental implant (tissue-level or bone-level) in implant stability, measured using resonance frequency analysis (RFA) and insertion torque (IT). We analyzed 234 titanium dental implants, placed in fresh calf ribs, at the half-tissue level and half-bone level. The implant surface was subjected to grit-blasting treatments with alumina particles of 120, 300, and 600 μm at a projection pressure of 2.5 bar, resulting in three types of roughness. Roughness was determined via optical interferometry. The wettability of the surfaces was also determined. Implant stability was measured using a high-precision torquemeter to obtain IT, and RFA was used to determine the implant stability quotient (ISQ). The results show that rough surfaces with Sa values of 0.5 to 4 μm do not affect the primary stability. However, the type of implant is important; bone-level implants obtained the highest primary stability values. A good correlation between the primary stability values obtained via IT and ISQ was demonstrated. New in vivo studies are necessary to know whether these results can be maintained in the long term.

Longitudinal Study of Bone Height Change between Two Approaches for Sinus Floor Elevation

Background and Objectives: The purpose of this study is to assess the long-term maintenance of each approach of sinus elevation, the crestal approach and lateral approach, by comparing the radiographic results of each technique. Materials and Methods: In total, 103 patients who had undergone an implant procedure with either the crestal approach or lateral approach method applied to their maxillary molar edentulous area were included. Using orthopantomographs, the radiographic changes were consistently evaluated over 3 years after the procedure (immediately after procedure and 1 year, 2 years and 3 years after implant placement) Results: The radiographic evaluation after 3 years of implantation with sinus elevation showed a significant amount of bone formation (8.07 mm for crestal approach and 12.00 mm for lateral approach method). The largest amount of grafted height loss occurred during the 1 year, but the resorption was minimal (0.98 mm for crestal approach and 0.95 mm for lateral approach method) over the entire 3 years. Conclusions: Although the lateral approach showed more bone growth, the amount of bone resorption was similar to that of the crestal approach. Both methods showed the highest amount of bone resorption in the first year, and the amount of change thereafter was insignificant. It is judged that both methods can be used according to the situation to help implant placement.

Reliability of implant stability measuring devices depending on various clinical conditions: an in vitro study

PURPOSE

The aim of this study was to evaluate the reliability of implant stability measuring devices depending on the location of the implant and the position of the patient.

MATERIALS AND METHODS

Six implants were installed in different dentate sextants of six artificial bone models. Implant stability was measured in three conditions of the bone model (without mounting on a phantom head, mounted on a phantom head in supine position, and mounted on a phantom head in upright position). A resonance frequency analysis device (Osstell) and two damping capacity analysis devices (Periotest and Anycheck) were used to measure implant stability. The values measured outside the phantom head were treated as controls, and the values inside the phantom head were compared using an independent t-test.

RESULTS

Osstell showed different results in two of the six divisions in both the supine and upright positions compared to outside of the mouth (P < .05). Periotest showed different results in all six parts in the supine position and in five parts in the upright position compared to outside of the mouth (P < .05). While Anycheck showed different results in five areas in the supine position compared to outside of the mouth, it showed different results in only one area in the upright position (P < .05).

CONCLUSION

In the difficult implant position for the operator to access, the implant stability measuring devices show less reliability. The accessibility of implant is greatly affected in the order of Osstell, Anycheck, and Periotest.

Comparative evaluation of implant stability and crestal bone level between tapered and cylindrical implants in the posterior regions of the mandible: A prospective, randomized, split-mouth clinical trial

Purpose

To compare the clinical outcome of tapered and cylindrical implants placed in the posterior region of mandible by measuring implant stability and crestal bone level at the healing period.

Materials and Methods

A prospective clinical study was conducted on 15 patients who were included in the study based on the inclusion and exclusion criteria. A total of 30 dental implants were placed in both groups: 15 implants in Group I (tapered implants) and 15 implants in Group II (cylindrical implants) in the posterior region of mandible. Implant stability assessment by periotest was done at the time of implant placement (baseline) and after 3 months. The crestal bone level was measured with the help of radiovisiography (RVG) at the time of implant placement (baseline) and at 3 and 6 months.

Results

At baseline, there was statistically significant (P < 0.01) difference in primary implant stability. Tapered implants had higher primary implant stability than cylindrical implants. However, at 3 months, there was no statistically significant (P > 0.05) difference in the secondary implant stability of both the groups. Also, the crestal bone level on the mesial and distal sides of dental implant for tapered and cylindrical implants was statistically nonsignificant (P > 0.05) at all time intervals, that is, at baseline and at 3 and 6 months.

Conclusion

Tapered implants had higher primary stability than cylindrical implants, and no difference was found in secondary stability. The crestal bone level was similar for both groups during early healing and early post-loading periods.

Correlation between CT - derived bone density and optimal bone densities acquired from CBCT scans

It is of interest to explore the correlation between preoperative bone density, assessed via CBCTT, and primary stability of dental implants, assessed by torque ratchet. A total of 100 patients who had implant placed were taken a sample for this retrospective study. The Hounsfield units (HU) derived preoperative bone densities at implant sites that were acquired with the help of the CBCT and the primary stability was achieved during the day of surgery. Both were compared to optimum bone densities. Statistical correlation was done between the HU and Bone density. Data suggests that evaluating HU values, along with other parameters, before performing implant surgery could lead to better primary implant stability.

A mathematical approach to estimate micro-displacement of a dental implant using electromagnetic Frequency Response Analysis

The aim of this paper is to formulate a mathematical model of dental prosthetic using single degree of freedom (SDOF) to assess the micro-displacement under electromagnetic excitation. Using Finite Element Analysis (FEA) and values from literature, stiffness and damping values of the mathematical model were estimated. For ensuring the successful implantation of dental implant system, monitoring of primary stability in terms of micro-displacement is crucial. One of the most popular techniques for the measurement of stability is the Frequency Response Analysis (FRA). This technique assesses the resonant frequency of vibration corresponding to the maximum micro-displacement (micro-mobility) of the implant. Among the different FRA techniques, the most common method is the Electromagnetic FRA. The subsequent displacement of the implant in the bone is estimated by equations of vibration. A comparison has been made to observe the variation in resonance frequency and micro-displacement due to varying input frequency ranges of 1-40 Hz. The micro-displacement and corresponding resonance frequency were plotted using MATLAB and the variation in resonance frequency is found to be negligible. The present mathematical model is a preliminary approach to understand the variation of micro-displacement with reference to electromagnetic excitation force and to obtain the resonance frequency. The present study validated the use of input frequency ranges (1-30 Hz) with negligible variation in micro-displacement and corresponding resonance frequency. However, input frequency ranges beyond 31-40 Hz is not recommended due to large variation in micromotion and corresponding resonance frequency.

A three-year prospective cohort study evaluating implant stability utilising the osstell® and periotest™ devices

Objectives

To investigate implant stability measurements from two different devices and at three different time points in order to determine their level of correlation. To also evaluate the influence of a range of clinical characteristics on the values produced by the devices at these three time points.

Materials &amp; Methods

Measurements were recorded at implant placement (T1), implant exposure (T2) and at 3 years from implant placement (T3). A range of clinical data was collected including patient demographics and site characteristics. Stability measurements and clinical characteristics were recorded for 29 patients and 68 dental implants at T1, subsequent stability measurements were recorded for 67 implants at T2 and 58 implants at T3. Correlation testing between the Osstell® and Periotest™ devices was carried out utilising Spearman's rank correlation for each time point. Analysis of the difference between clinical factors and stability measurements was compared using Krushal-Wallis test for each variable and time point.

Results

A single dental implant failed shortly after 2nd stage surgery for an overall survival rate of 98% during the study timeline. The median ISQ value was 73.25 (IQR 67–75) at T1 and 74 (IQR 70.5–77) at T3. The median Periotest value was −4 (IQR −6, −2) at T1 and −6 (IQR −7, −5) at T3. The range of ISQ values observed was 50 (39–89) ISQ at T1 and decreased to 21 (61–82) ISQ at T3. The Periotest values ranged from 37 (29 to −8) at T1 and decreased to 6 (−2 to −8) at T3. A weak to moderate correlation was observed between mean ISQ and Periotest values across time-points T1, T2 and T3, (r = −0.26, p = 0.05), (r = −0.35, p &lt; 0.01) and (r = −0.28, p = 0.04) respectively.

Conclusions

Based on the results of this study there was a weak to moderate level of correlation between values recorded between the two measurement devices at implant placement, implant exposure and three years following placement. For both the Osstell® and Periotest™ a narrowing of the range of stability values was observed from T1 to T3. In general, Periotest™ seemed to be more sensitive in highlighting differences in measurements affected by local conditions.

Clinical application of platelet-rich fibrin to enhance dental implant stability: A systematic review and meta-analysis

Objective

To investigate the effect of platelet-rich fibrin application on implant stability.

Study design

Five databases, namely, PubMed, Embase, Web of Science, Wiley, and China National Knowledge Infrastructure, were searched for reports published up to November 20, 2022. Randomized controlled trials (RCT), including parallel RCTs and split-mouth RCTs, with at least 10 patients/sites were considered for inclusion.

Results

After screening based on the inclusion criteria, ten RCTs were included. Low heterogeneity was observed in study characteristics, outcome variables, and estimation scales (I² = 27.2%, P = 0.19). The qualitative and meta-analysis results showed that PRF increased the effect of implant stabilizers after implant surgery.

Conclusions

The results of the present systematic review and meta-analysis suggest that PRF can increase implant stability after implant surgery. PRF may also have a role in accelerating bone healing and tends to promote new bone formation at the implant site.

Long-Term Follow-up of a Wide-Diameter Bone-Anchored Hearing Implant: 10-Year Experience on Stability, Survival, and Tolerability of an Implant-Abutment Combination

OBJECTIVE

To compare stability, survival, and soft tissue reactions between a wide-diameter (test) and previous-generation small-diameter (control) bone-anchored hearing implant and to ascertain the safety of loading the test implant 3 weeks after surgery, at a long-term follow-up of 10 years.

STUDY DESIGN

This study is a continuation of two previously completed, multicenter, randomized, controlled trials and consisted of one to two additional follow-up visits until 10 years after surgery.

PATIENTS

Fifty-one of the 72 participants from the previous trials were included. Patients received a test or control implant. All control implants were loaded 6 weeks after surgery (group A). Test implants were loaded 3 (group B) or 6 weeks (group C) after surgery.

RESULTS

The test implant showed significantly higher implant stability quotient (ISQ) values than the control implant throughout the 10-year follow-up. At 10 years, the mean ISQ-high values for both implants were higher than at the first follow-up visit. No significant differences in change of ISQ-high from baseline to 10 years were noticed between both implants and loading groups. Soft tissue reactions were rarely seen. At 10-year follow-up, no patients presented with adverse soft tissue reactions. Excluding explantations, the implant survival rate was 78.6% (group A), 100% (group B), and 90.0% (group C).

CONCLUSIONS

The test implant showed superior mean ISQ values and significantly better implant survival throughout 10-year follow-up. In addition, the current study concludes that it is safe to load the test implant at 3 weeks after surgery, as long-term results show high ISQ values and good implant survival.

Modelling the resonant frequency associated with the spatio-temporal evolution of the bone-dental implant interface

Dental implant stability is greatly affected by the mechanical properties of the bone-implant interface (BII), and it is key to long-term successful osseointegration. Implant stability is often evaluated using the Resonant Frequency Analysis (RFA) method, and also by the quality of this interface, namely the bone-implant contact (BIC). True to this day, there is a scarcity of models tying BIC, RFA and a spatially and mechanically evolving BII. In this paper, based on the contact/distance osteogenesis concept, a novel numerical spatio-temporal model of the implant, surrounding bone and evolving interface, was developed to assess the evolution of the interfacial stresses on the one hand and the corresponding resonant frequencies on the other. We postulate that, since the BIC percentage reaches saturation over a very short time, long before densification of the interface, it becomes irrelevant as to load transmission between the implant and the bone due to the existence of an open gap. Gap closure is the factor that provides continuity between the implant and the surrounding bone. The results of the calculated RFA evolution match and provide an explanation for the multiple clinical observations of a sharp initial decline in RFA, followed by a gradual increase and plateau formation. STATEMENT OF SIGNIFICANCE: A novel three-dimensional numerical model of an evolving bone-dental implant interface (BII) is presented. The spatio-temporal evolution of the bone-implant contact (BIC) and the BII, based on contact/distance (CO/DO) osteogenesis, is modeled. A central outcome is that, until BII maturation into a solid continuous bone (no open gap between CO-DO fronts), the bone-implant load transfer is hampered, irrespective of the BIC. The resonant frequencies' evolution of the jawbone-BII-implant is calculated to reproduce the well-established implant stability analysis based on the Resonant Frequency Analysis. The results resemble those reported clinically, and here too, the determinant transition occurs only after interfacial gap closure. Those results should motivate clinicians to re-consider structural continuity of the BII rather than the BIC only.

The Construction and Evaluation of a Multi-Task Convolutional Neural Network for a Cone-Beam Computed-Tomography-Based Assessment of Implant Stability

Objectives: Assessing implant stability is integral to dental implant therapy. This study aimed to construct a multi-task cascade convolution neural network to evaluate implant stability using cone-beam computed tomography (CBCT). Methods: A dataset of 779 implant coronal section images was obtained from CBCT scans, and matching clinical information was used for the training and test datasets. We developed a multi-task cascade network based on CBCT to assess implant stability. We used the MobilenetV2-DeeplabV3+ semantic segmentation network, combined with an image processing algorithm in conjunction with prior knowledge, to generate the volume of interest (VOI) that was eventually used for the ResNet-50 classification of implant stability. The performance of the multitask cascade network was evaluated in a test set by comparing the implant stability quotient (ISQ), measured using an Osstell device. Results: The cascade network established in this study showed good prediction performance for implant stability classification. The binary, ternary, and quaternary ISQ classification test set accuracies were 96.13%, 95.33%, and 92.90%, with mean precisions of 96.20%, 95.33%, and 93.71%, respectively. In addition, this cascade network evaluated each implant's stability in only 3.76 s, indicating high efficiency. Conclusions: To our knowledge, this is the first study to present a CBCT-based deep learning approach CBCT to assess implant stability. The multi-task cascade network accomplishes a series of tasks related to implant denture segmentation, VOI extraction, and implant stability classification, and has good concordance with the ISQ.

The Effect of Laser Micro Grooved Platform Switched Implants and Abutments on Early Crestal Bone Levels and Peri-Implant Soft Tissues Post 1 Year Loading among Diabetic Patients-A Controlled Clinical Trial

Background and Objectives: The study aimed to compare the mean crestal bone level (CBL) and peri-implant soft tissue parameters in laser micro-grooved (LMG) platform switched implants and abutments (I&A) post 1 year of functional loading among non-diabetic and type II diabetic individuals. Materials and methods: Patients with an edentulous site having minimum bone height and width of ≥13 mm and ≥6 mm, respectively, were divided into two groups: (i) Non-diabetic-8 (control) and (ii) diabetic-8 (test). LMG Implants were placed and loaded immediately with a provisional prosthesis. Mean crestal bone level (MCBL) was evaluated radiographically at baseline and at 1 year. Peri-implant attachment level (PIAL) and relative position of the gingival margin (R-PGM) were recorded. Implant stability quotient (ISQ) level and implant survival rate (ISR) were evaluated at 1 year. Results: Early MCBL within the groups 1 year postloading was similar both mesially and distally (control-0.00 to 0.16 mm and 0.00 to 0.17 mm, respectively; test-0.00 to 0.21 mm and 0.00 to 0.22 mm, respectively) with statistical significance (p ≤ 0.003, p ≤ 0.001 and p ≤ 0.001, p ≤ 0.001, respectively). However, intergroup comparison showed no significant difference statistically in the MCBL in 1 year post functional loading. The peri-implant soft tissue parameters showed no significant difference between the groups. ISQ level between both groups did not reveal any significant changes (p ≤ 0.92), and ISR was 100%. Conclusions: LMG Implants resulted in minimal and comparable early crestal bone loss and soft tissue changes post 1 year of functional loading in moderately controlled diabetic and non-diabetic individuals, suggesting that this could be a reliable system for use in systemically compromised individuals.

Evaluation of Correlation between Vitamin D Levels and Implant Stability in Indian Population: A Prospective Study in Bangalore

Purpose

Dental implants have become a definitive method for the esthetic and functional rehabilitation of both partially and completely edentulous arch. There is a significant role of vitamin D in bone metabolism and there are only few human studies that evaluate the effect of vitamin D deficiency on stability of dental implants. The study thus aims to evaluate the correlation of vitamin D deficiency and implant stability in delayed endosseous implant.

Methods

The study included 20 subjects of either gender in the age group of 20-50 years, who required implant placement for rehabilitation of partially edentulous condition. Vitamin D status was evaluated for all subjects preoperatively. Implant stability was checked postoperatively at three months and six months using Electronic Technology Resonance Frequency Analysis.

Results

The study found that for every 1 ng/ml increase in Vitamin D levels, the implant stability Quotient value (ISQ) significantly increased by 0.48 at 3 months and 0.62 units at 6 months, which was statistically significant at P = 0.01 and P = 0.002, respectively. Statistical analysis was done using Student Paired t test, Pearson Correlation test and Simple Linear regression analysis.

Conclusion

Albeit the smaller sample size, the results of the study showed the positive influence of vitamin D on stability of implant. The study thus emphasizes on the significance of screening the vitamin D status of subjects prior to implant placement.

Clinical and radiographic outcomes of dental implant after maxillary sinus floor augmentation with rhBMP-2/hydroxyapatite compared to deproteinized bovine bone

Objectives

This study aimed to evaluate the clinical and radiographic outcomes of early implant placement and functional loading in maxillary sinus floor augmentation (MSFA) using recombinant human bone morphogenetic protein 2/hydroxyapatite (rhBMP-2/HA) and to compare these outcomes with those of the conventional protocol in MSFA using deproteinized bovine bone (DBB).

Materials and methods

The rhBMP-2/HA and DBB groups consisted of 14 and 13 patients who underwent MSFA with BMP and DBB, respectively. After placement of 22 implants and 21 implants in the rhBMP-2/HA and DBB groups, respectively, abutment connections were performed 3 months after implant placement for the rhBMP-2/HA group and 6 months after implant placement for the DBB group. Changes in grafted sinus height (GSH), marginal bone loss (MBL), and implant stability were evaluated up to one year after functional loading.

Results

Survival rates for the rhBMP-2/HA and DBB groups after one year of functional loading were 90.9% and 90.5%, respectively. Both groups exhibited no significant time-course changes in GSH until one year of functional loading (rhBMP-2/HA, p = 0.124; DBB, p = 0.075). Although significant MBL occurred after one year of functional loading for both groups (rhBMP-2/HA, p < 0.001; DBB, p < 0.001), there were no significant differences in time-course changes in MBL between the two groups (p = 0.450). The mean implant stability quotient values in the rhBMP-2/HA and DBB groups were 75.3 and 75.4 after one year of functional loading, respectively, and there were no significant differences between the two groups (p = 0.557).

Conclusions

MSFA using rhBMP-2/HA allowed implant rehabilitation with early implant placement and functional loading and led to a comparable survival rate and implant stability after 1 year of functional loading with acceptable MBL and stable maintenance of GSH compared to the MSFA using DBB with 6 months of healing after implant placement.

Impact of Three Different Surgical Drilling Protocols on Early Loaded Single Implant in Posterior Maxilla: A 3-year Follow-up

AIM

This study aims to compare three different drilling techniques for implant site preparation to enhance the primary stability of the early loaded single implant in the posterior maxilla.

MATERIALS AND METHODS

A total of 36 dental implants were used in this study for the replacement of a missing single tooth or more in the maxillary posterior region with an early loaded dental implant. The patients were randomly divided into three groups. In group I, the drilling was performed using an undersized drilling technique, in group II, the drilling was performed using bone expanders, and in group III, the drilling was performed using the osseodensification (OD) technique. Patients were evaluated clinically and radiographically at regular time intervals immediately, 4 weeks, 6 months, 1 year, 2 years, and 3 years after surgery. All clinical and radiographic parameters were subjected to statistical analysis.

RESULTS

All implants in group I were stable and successful, while 11 from 12 implants survived in both groups II and III. There was no significant difference in peri-implant soft tissue health and marginal bone loss (MBL) throughout the whole study period between the three groups, while there was a significant difference in implant stability and insertion torque between groups I, II, and III at the time of implant placement.

CONCLUSION

Preparing the implant bed using the undersized drilling technique with drills with similar geometry to the implant being inserted provides high implant primary stability without the need for additional instruments or cost.

CLINICAL SIGNIFICANCE

Dental implants can be early loaded in the posterior maxilla by using an undersized drilling technique, as it improves primary stability.

Intra- and inter-operator concordance of the resonance frequency analysis. A cross-sectional and prospective clinical study

OBJECTIVE

Resonance frequency analysis (RFA) provides an evaluation of implant stability over time. This analysis is a non-invasive, precise, and objective method. Several studies compare the RFA system with other devices. However, few investigations analyze repeatability and reproducibility between different operators. The aim of this study was to evaluate the intra- and inter-operator concordance of the Osstell® ISQ.

MATERIAL AND METHODS

RFA measurements were performed with Osstell® ISQ in a total of 37 implants placed in 21 patients. At the time of implant placement, 6 measurements per implant were taken by three different experienced operators. Three measurements were carried out consecutively and three by removing and placing the SmartPeg-Osstell® to assess intra-operator and inter-operator agreement.

RESULTS

Intra-operator concordance according to the intraclass correlation coefficient (ICC) showed high concordance. The ICC values were higher than 0.9 (p < 0.0001) for consecutive measures and alternative measures, being almost perfect of Landis & Koch classification. For inter-operator concordance The ICC was 0.709 (p < 0.0001) and 0.670 (p < 0.0001) for consecutive and alternative measures, respectively, both estimates being in the substantial category. In torque and ISQ values, no statistically significant differences were observed when operators and measurements were compared.

CONCLUSIONS

Osstell® ISQ system was stable both in intra-operator and inter-operator measurements. This device has excellent repeatability and reproducibility, demonstrating reliability to measure the stability of dental implants.

CLINICAL RELEVANCE

Resonance frequency analysis (RFA) is a non-invasive, objective, and reliable diagnostic method to determine the ideal moment to load the implant, as well as to predict possible failures.

Electrochemical deposition of lithium coating on titanium implant with enhanced early stage osseointegration

Recently, a large number of studies have reported that lithium (Li) displayed a positive effect on osteogenesis. However, only a few studies have investigated the Li-incorporated surfaces through electrochemical deposition. In this study, electrochemical deposition was conducted on a CHI600E electrochemical workstation. The characterization of electrochemical deposition (ECD) and ECD-Li surfaces were detected by field-emission scanning electron microscopy with energy-dispersive spectrometer. rBMSCs were cultured on two surfaces for subsequent adhesion, proliferation and live/dead assay. To evaluate the effects of Li-incorporated implants by electrochemical deposition on osseointegration in vivo, teeth extraction of two premolars and one first molar in bilateral mandible were performed on six male beagle dogs. After 3 months, ZDI and ZDI-Li implants were inserted into the bilateral mandible of each beagle dog. Micro Computed Tomography (Micro-CT) and hard tissue sectioning analysis were carried out to evaluate the osseointegration at 4- and 8-weeks post-implantation. Results showed that ECD-Li surface promoted adhesion and proliferation of BMSCs in the early stage. More importantly, through micro-CT analysis, the values of bone volume/total volume (BV/TV) (0.374 ± 0.015), bone-implant contact (BIC) (0.831 ± 0.025), and Tb.Th (0.412 ± 0.007) in ZDI-Li group was significantly higher than those of ZDI group (0.302 ± 0.009, 0.700 ± 0.023, 0.353 ± 0.001, p < .01) at 4 weeks. Similarly, ZDI-Li group manifested more bone contact with the implant surfaces at 4 weeks based on hard tissue sectioning analysis, whereas no significant difference was detected between two groups at 8 weeks. Therefore, incorporating Li into implant surface through ECD could enhance early osseointegration in vivo.

Implant stability of narrow diameter implants in hyperglycemic patients-A 3-month case-control study

OBJECTIVES

The aim of this prospective case-control study was to compare the development of implant stability quotients of narrow diameter implants in patients with type 2 diabetes mellitus (T2DM) and healthy individuals within the first 3 months after implant insertion.

METHODS

Sixteen patients with T2DM (HbA1C > 6.5%) as test group and 16 nondiabetic patients (HbA1C < 5.9%) as the control group were evaluated. All patients received narrow-diameter tissue level implants in an edentulous area posterior to the canine. The implant stability was measured by means of resonance frequency analysis after 3 days, 7 days, 4 weeks, and 3 months postplacement. Statistical analysis of intergroup differences and correlation to HbA1c values and treated jaw was performed in PRISM 8.

RESULTS

The means for implant stability quotients showed a significant increase between Day 3 and 3-month assessment in both groups. No significant differences between study groups and no correlation of implant stability to HbA1c were found.

CONCLUSION

The present study shows encouraging clinical outcomes for narrow-diameter implants inserted in the posterior zone in patients with uncontrolled T2DM.

Primary Implant Stability Analysis of Different Dental Implant Connections and Designs-An In Vitro Comparative Study

Primary implant stability can be evaluated at the time of placement by measuring the insertion torque (IT). However, another method to monitor implant stability over time is resonance frequency analysis (RFA). Our aim was to examine the effect of bone type, implant design, and implant length on implant primary stability as measured by IT and two RFA devices (Osstell and Penguin) in an in vitro model. Ninety-six implants were inserted by a surgical motor in an artificial bone material, resembling soft and dense bone. Two different implant designs-conical connection (CC) and internal hex (IH), with lengths of 13 and 8 mm, were compared. The results indicate that the primary stability as measured by RFA and IT is significantly increased by the quality of bone (dense bone), and implant length and design, where the influence of dense bone is similar to that of CC design. Both the Osstell and Penguin devices recorded higher primary implant stability for long implants in dense bone, favoring the CC over the IH implant design. The CC implant design may compensate for the low stability expected in soft bone, and dense bone may compensate for short implant length if required by the anatomical bone conditions.

Immediate implant placement with platelet rich fibrin as space filling material versus deproteinized bovine bone in maxillary premolars: A randomized clinical trial

BACKGROUND

Several biomaterials have been suggested to augment the jumping gap during immediate implant placement.

PURPOSE

The aim of this study was to compare the effect of xenograft or platelet derived growth factor (PRF) to graft the jumping gap in immediate implant placement in the maxillary premolar region.

MATERIALS AND METHODS

Twenty patients underwent atraumatic extraction followed by immediate placement. The patients were equally divided into two groups. The first group received xenograft as a jumping gap filling material. The second group received PRF to graft the jumping gap. All patients received preoperative, immediate postoperative, and 6 months postoperative cone beam CT scan (CBCT). Implant stability quotient ISQ values were taken for the installed implants immediate postoperative and at 6 months.

RESULTS

Implants receiving PRF as a jumping gap graft material demonstrated a significantly greater amount of crestal bone loss 1.85 ± 0.89 mm as compared to xenograft group 0.77 ± 0.32 mm (t = 3.52, p = 0.005). PRF group showed significantly greater reduction in buccopalatal direction 1.63 mm as compared to xenograft group 0.59 mm (t = 4014, p <0.001). ISQ values were similar immediately postoperative (t = 0.070, p = 0.945) while the ISQ values were significantly lower in PRF group as compared to xenograft graft at the six-month interval (t = 0.248, p = 0.023).

CONCLUSION

The use of xenograft material as a jumping gap filling material resulted in superior results compared to PRF with regards to crestal bone loss, buccolingual socket reduction, and ISQ values.

Management and prevention of soft tissue complications in implant dentistry

The management and prevention of soft tissue complications is of key importance in modern implant dentistry and influences biologic and esthetic outcomes. The assessment of the soft tissue conditions from a quantitative and qualitative perspective should, therefore, be part of the overall treatment plan. Such an assessment dictates a potential indication as well as an ideal time point for additional soft tissue management. A proper risk assessment and management of the soft tissues at the planned implant site are of key importance prior to any implant‐related surgery. Cases with peri‐implant soft tissue complications generally involve: (a) a lack of attached and keratinized mucosa; (b) insufficient volume; (c) development of mucosal dehiscences; or (d) a combination of (a), (b), and (c). In case of soft tissue deficiencies, these should be addressed as early as possible to increase the predictability of the surgical interventions. This article reviews the main causes for peri‐implant soft tissue complications and presents different therapeutic options for the management of various clinical scenarios.

Clinical Evaluation of a Novel Laser-Ablated Titanium Implant System for Bone Anchored Hearing Systems in a Pediatric Population and the Relationship of Resonance Frequency Analysis With Implant Survival

OBJECTIVE

To evaluate the clinical outcomes of pediatric patients implanted a novel 4.5 mm wide laser ablated titanium bone anchored implant system and to evaluate the implant stability over the first 12-month period.

STUDY DESIGN

A prospective, single-subject, repeated measure, cohort study. Participants served as their own controls.

SETTING

Community and tertiary referral hospital pediatric assessment center.

PATIENTS

A total of 115 consecutive pediatric patients aged 4 to 15 years were implanted with 176 laser ablated titanium bone anchored implants from January 2016 to January 2019.

MAIN OUTCOME MEASURE

Clinical outcomes, implant failure rates, and post implantation implant stability quotient (ISQ) scores were studied over the first 12-month period. Data were analyzed for statistical significance through mixed effect modeling, with the significance level p = 0.01.

RESULTS

A median 12-month survival of 96.6% was observed. Six implants (3.5%) were lost in total, one of these (0.6%) was lost due to trauma. Adverse skin reactions (Holgers grade 2-4) were observed in 4.4% of all postoperative visits, occurring in 22 individuals (19.1%). Neither the ISQ high (ISQH) nor ISQ low (ISQL) values increased significantly between the stage 1 and 2 surgeries. In contrast, the ISQ results, irrespective of abutment size, demonstrated an increasing trend from 49.1 to 57 over the 12 months review period. A statistically significant change was only demonstrated from the 3 months follow up onwards.

CONCLUSION

The use of 4.5 mm wide laser-ablated titanium bone anchored hearing implants resulted in superior survival rates and excellent clinical outcomes compared with previous implant systems.

The stability of tetracalcium phosphate/titanium implants: A short-term follow-up study

Background/purpose

Materials and methods

Results

Conclusion

Nanostructured Zn-Substituted Monetite Based Material Induces Higher Bone Regeneration Than Anorganic Bovine Bone and β-Tricalcium Phosphate in Vertical Augmentation Model in Rabbit Calvaria

The capacity of a nanostructured multicomponent material composed of Zn-substituted monetite, amorphous calcium phosphate, hydroxyapatite and silica gel (MSi) to promote vertical bone augmentation was compared with anorganic bovine bone (ABB) and synthetic β-tricalcium phosphate (β-TCP). The relation between biological behavior and physicochemical properties of the materials was also studied. The in vivo study was conducted in a vertical bone augmentation model in rabbit calvaria for 10 weeks. Significant differences in the biological behavior of the materials were observed. MSi showed significantly higher bone regeneration (39%) than ABB and β-TCP (24%). The filled cylinder volume was similar in MSi (92%) and ABB (91%) and significantly lower in β-TCP (81%) implants. In addition, β-TCP showed the highest amount of non-osteointegrated particles (17%). MSi was superior to the control materials because it maintains the volume of the defect almost full, with the highest bone formation, the lowest number of remaining particles, which are almost fully osteointegrated and having the lowest amount of connective tissue. Besides, the bone formed was mature, with broad trabeculae, high vascularization and osteogenic activity. MSi resorbs gradually over time with an evident increment of the porosity and simultaneous colonization for vascularized new bone. In addition, the osteoinductive behavior of MSi material was evidenced.

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

ABSTRACT

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.

Short-Term Evaluation of Prosthetic Rehabilitation of Thin Wiry Ridge by Ridge Splitting and Simultaneous Implants Placement: Non-randomized Control Trial

Objective  This article evaluates the success of prosthetic rehabilitation of thin wiry ridge and implants placed simultaneously in splitted ridge both clinically and radiographically.

Materials and Methods  Twenty-one participants were enrolled of which 13 patients (8 females and 5 males) were suffering from maxillary ridge atrophy and 8 patients (5 females and 3 males) had mandibular ridge atrophy; a total of 42 implants were performed using the ridge expansion technique. The expansion was performed using the conventional disk technique, piezoelectric corticotomy, and self-threading expanders. Implants were placed and loaded with fixed partial denture after 4 months for the mandible and 6 months for the maxilla. Implant stability quotient (ISQ) was measured at T0 (implant placement) and TL (loading). Crestal bone levels were measured at different times: T0, TL, and T12 (12 months). Evaluation of prosthetic and surgical complications was carried out. Data were analyzed and compared using analysis of variance and paired t -tests at a significance level of 5%.

Results  All implants met the criteria for success. All implants showed a higher mean bone loss from T0 to TL (1.259 ± 0.3020) than from TL to T12 (0.505 ± 0.163) with a statistically significant difference ( p  < 0.0001). ISQ values sharply increased at the time of loading (72.52 ± 2.734) than at implant insertion (44.5 ± 4.062) with a significant difference ( p  < 0.0001). Minor prosthetic and surgical complications were reported.

Conclusion  The results from this study support the efficacy of prosthetic rehabilitation of thin wiry ridge using split ridge technique and the success of implants placed simultaneously in splitted ridge.

Clinical evaluation and resonance frequency analysis of laser-ablated titanium bone-anchored hearing implant system in children with Down Syndrome

OBJECTIVES

To evaluate complication rates and resonance frequency analysis (RFA) of the stability of a new laser-ablated titanium Bone Anchored hearing Implant system in children with Down syndrome.

METHODS

A prospective, single-subject, repeat measure, cohort study in which each participant served as their own control. Consecutive paediatric patients 4yrs- 15 years old, with a primary diagnosis of Down syndrome (trisomy 21) were implanted between January 2015-January 2020 with BHX Oticon wide implants. Evaluation of soft tissue reactions, fixture failure rates and post implantation Implant stability Quotient (ISQ) at both fixtures and abutment levels were studied over a 12-month period. Data was analysed for statistical significance through mixed effect modelling with significance set at p = 0.01.

RESULTS

31 consecutive paediatric patients with a diagnosis of Down syndrome were implanted with 43 Ponto BHX Oticon™ implant system. Twelve children had bilateral implants and nineteen were unilateral. Over the 12 month follow up 2 fixtures (4.6%) were lost, and adverse skin reactions (Holgers >2) were recorded in 3.2% of all clinical reviews. Implant level stability quotient showed no statically significant change between first and second stage 71.1-71.7. Abutment level ISQ increased from 46.2 to 56.7 p = 0.0001 at the 12-month review point as compared to that recorded at loading.

CONCLUSION

Implant survival and adverse skin reactions were found to be in keeping with those in published literature and much improved compared to previous implant systems placed at this centre. Although abutment level ISQ showed an increase over the review period no correlation between this and implant loss can be concluded.

Stability of Dental Implants and Thickness of Cortical Bone: Clinical Research and Future Perspectives. A Systematic Review

Dental surgery implantation has become increasingly important among procedures that aim to rehabilitate edentulous patients to restore esthetics and the mastication ability. The optimal stability of dental implants is correlated primarily to the quality and quantity of bone. This systematic literature review describes clinical research focusing on the correlation between cortical bone thickness and primary/secondary stability of dental fixtures. To predict successful outcome of prosthetic treatment, quantification of bone density at the osteotomy site is, in general, taken into account, with little attention being paid to assessment of the thickness of cortical bone. Nevertheless, local variations in bone structure (including cortical thickness) could explain differences in clinical practice with regard to implantation success, marginal bone resorption or anchorage loss. Current knowledge is preliminarily detailed, while tentatively identifying which inconclusive or unexplored aspects merit further investigation.

Machine Learning-Based Diagnosis in Laser Resonance Frequency Analysis for Implant Stability of Orthopedic Pedicle Screws

Evaluation of the initial stability of implants is essential to reduce the number of implant failures of pedicle screws after orthopedic surgeries. Laser resonance frequency analysis (L-RFA) has been recently proposed as a viable diagnostic scheme in this regard. In a previous study, L-RFA was used to demonstrate the diagnosis of implant stability of monoaxial screws with a fixed head. However, polyaxial screws with movable heads are also frequently used in practice. In this paper, we clarify the characteristics of the laser-induced vibrational spectra of polyaxial screws which are required for making L-RFA diagnoses of implant stability. In addition, a novel analysis scheme of a vibrational spectrum using L-RFA based on machine learning is demonstrated and proposed. The proposed machine learning-based diagnosis method demonstrates a highly accurate prediction of implant stability (peak torque) for polyaxial pedicle screws. This achievement will contribute an important analytical method for implant stability diagnosis using L-RFA for implants with moving parts and shapes used in various clinical situations.

Effects of platelet concentrates on implant stability and marginal bone loss: a systematic review and meta-analysis

Background

Osseointegration is essential for the success and stability of implants. Platelet concentrates were reported to enhance osseointegration and improve implant stability. The purpose of this review is to systematically analyze the effects of platelet concentrates on implant stability and marginal bone loss.

Methods

Two researchers independently performed searches in the following databases (last searched on 21 July 2021): MEDLINE (PubMed), Cochrane Library, EMBASE, and Web of Science. In addition, a manual search was carried out on references of relevant reviews and initially included studies. All randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on the application of platelet concentrates in the implant surgery procedure were included. The risk of bias of RCTs and CCTs were assessed with a revised Cochrane risk of bias tool for randomized trials (RoB 2.0) and the risk of bias in non-randomized studies—of interventions (ROBINS-I) tool, respectively. Meta-analyses on implant stability and marginal bone loss were conducted. Researchers used mean difference or standardized mean difference as the effect size and calculated the 95% confidence interval. In addition, subgroup analysis was performed based on the following factors: type of platelet concentrates, method of application, and study design.

Results

Fourteen studies with 284 participants and 588 implants were included in the final analysis. 11 studies reported implant stability and 5 studies reported marginal bone level or marginal bone loss. 3 studies had high risk of bias. The meta-analysis results showed that platelet concentrates can significantly increase implant stability at 1 week (6 studies, 302 implants, MD 4.26, 95% CI 2.03–6.49, P < 0.001) and 4 weeks (8 studies, 373 implants, MD 0.67, 95% CI 0.46–0.88, P < 0.001) after insertion, significantly reduced marginal bone loss at 3 months after insertion (4 studies, 95 implants, mesial: MD − 0.33, 95% CI − 0.46 to − 0.20, P < 0.001; distal: MD − 0.38, 95% CI − 0.54 to − 0.22, P < 0.001). However, the improvement of implant stability at 12 weeks after insertion was limited (P = 0.10). Subgroup analysis showed that PRP did not significantly improve implant stability at 1 week and 4 weeks after insertion (P = 0.38, P = 0.17). Platelet concentrates only placed in the implant sites did not significantly improve implant stability at 1 week after insertion (P = 0.20).

Conclusions

Platelet concentrates can significantly improve implant stability and reduce marginal bone loss in the short term. Large-scale studies with long follow‐up periods are required to explore their long-term effects and compare effects of different types.

Trial registration

This study was registered on PROSPERO, with the Registration Number being CRD42021270214.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01929-x.

Laser resonance frequency analysis of pedicle screw stability: A cadaveric model bone study

There is no evaluation method currently available to assess intraoperative pedicle screw fixation (PSF) strength. In this study, we established a laser-based resonance frequency analysis (RFA) system with high-speed, noncontact, quantitative measurements of PSF. Clinical investigations in the future can assess surgical failure risk of implants. We investigated the characteristics of the laser RFA and compared them with the conventional methods. We inserted a pedicle screw in the vertebral pedicle of human cadaver or model bone, followed by screw pull-out, peak torque, implant stability quotient (ISQ) value obtained by the magnetic dental RFA system, and fixation force of laser RFA. We compared the outcomes using best-fit linear or logarithmic approximations. For the model bone study, the resonance frequency (RF) versus peak torque/pull-out force (POF) demonstrated strong correlations using logarithmic approximation (vs. peak torque: R = 0.931, p < .001, vs. POF: R = 0.931, p < .001). RF strongly correlated with the ISQ value using linear approximation (R = 0.981, p < .001). For the cadaveric vertebrae study, the correlation coefficients between RF and the peak torque/POF were significant regardless of approximation method (peak torque: logarithmic: R = 0.716 vs. linear: R = 0.811; p < .001) (POF: logarithmic: R = 0.644 vs. linear: R = 0.548; p < .05). Thus, the results of this study revealed a constant correlation between RFA and conventional methods as a measurement validation, predicting favorable support for intraoperative PSF. RFA has the potential to be a new index for evaluating the implant fixation force.