Primary Stability Of Implants Research Articles

Evaluation of thin-threaded implants primary stability in type IV bone right after maxillary sinus floor elevation: A human cadaver study.

The bone-implant interface plays a crucial role in obtaining sufficient primary stability for dental implants in weak bone supports. The aim of this human cadaver study was to evaluate the primary stability of new thin-threaded implants when placed in type IV bone right after maxillary sinus floor elevation. The study followed the CACTUS (ChAracteristics of Cadaver Training and sUrgical Studies) guidelines. Twenty-four edentulous maxillary posterior zones with type IV bone and a residual bone height of 4mm were selected using computed tomography scans. First, an osteotome sinus floor elevation was performed (C.M.C Tech, IBS IMPLANT, Daejeon, South Korea). Implants with thin threads (MagiCore, IBS IMPLANT, Daejeon, South Korea) were placed simultaneously. Samples were divided into two groups: Group 1 (G1): 11mm-long implants with an elevation of 8mm; Group 2 (G2): 7mm-long implants with an elevation of 4mm. Primary stability was assessed using resonance frequency analysis (RFA). The average primary stability values in the mesiodistal (MD) direction were 45.67±3.09 Implant Stability Quotient (ISQ) for G1 and 38.76±16.94 ISQ for G2, and in the buccolingual direction were 43.33±13.23 ISQ for G1 and 38.47±16.14 ISQ for G2. The primary stability of the thin-threaded implants was compatible with clinical osseointegration in sinus sites with limited bone contact area in both experimental situations. Clinical studies are needed to confirm these encouraging results.

Osseodensification versus piezoelectric internal sinus elevation (PISE) technique in delayed implant placement (a randomized controlled clinical trial)

Transalveolar sinus elevation is a minimally invasive technique aimed at augmenting the vertical bone height in the posterior maxilla, facilitating successful implant placement in areas with insufficient bone volume. This study compares the efficacy of osseodensification and piezoelectric internal sinus elevation (PISE) techniques in delayed implant placement. The primary objective was to radiographically assess vertical bone gain and bone density, while secondary objectives included clinical assessment of primary implant stability and post-operative satisfaction of both patients and operators. The study population of a total of 16 patients was randomly divided into two groups. Group 1 underwent osseodensification sinus lift using sticky bone as a graft material, whereas Group 2 received PISE with the same graft material. Results indicated that the osseodensification technique led to greater bone gain, improved bone density, and shorter surgical duration. Additionally, osseodensification was associated with enhanced rapid healing and higher patient satisfaction. Conversely, the PISE technique demonstrated superior primary stability of implants on the day of surgery. These findings suggest that while both techniques are effective, osseodensification may offer advantages in terms of bone gain, density, and patient satisfaction, making it a reliable method for enhancing rapid healing in delayed implant placement. the study was registered on clinicaltrials.gov at 26th September 2023 and clinical trials ID is NCT06055127.

Primary Stability and Osseointegration of the Implant in an Iatrogenically Oversized Cavity by Bone Substitute: An Animal Study

Background: The aim of this study was to compare the success rate of autogenous bone and combination of autogenous bone and beta-tricalcium phosphate (β-TCP) grafts in restoring the primary stability and osseointegration of dental implants after the oversized preparation of the bone cavity in animal models. Methods: Three months after extracting 3 premolars from 4 male Terrier dogs, 24 implants were inserted in cavities larger than the fixture size. Then, based on the type of graft materials around the implant fixture, they were randomly divided into the autogenous bone group (A, n=8), the autogenous bone group with β-TCP (B, n=8), and the control group with no grafts (C, n=8). After 16 weeks, the removal torque quantity (RTQ) test and Periotest® were used for osseointegration assessment. Results: According to the results of the RTQ test, group B was significantly higher than group C (P=0.022), but no statistical difference was observed between groups A and B, as well as groups A and C. Based on the results, the Periotest® value significantly differed in group B compared to groups A (P=0.049) and C (P=0.014), but there was no difference between groups A and C in this regard. Conclusions: According to the findings of the study, the combination of autogenous bone graft and TCP could improve secondary stability and osseointegration of dental implants.

The Effect of Increasing Thread Depth on the Initial Stability of Dental Implants: An In Vitro Study

Background: The long-term success of dental implants largely depends on achieving primary stability, previously described as crucial to obtaining osseointegration and immediate loading protocol requirements. Implant thread depths seem to be one of the key factors influencing primary stability, particularly in low-density bone. Insertion torque (IT) and resonance frequency analysis (RFA) are considered the most reliable tests to assess primary stability. The aim of this work was to evaluate how different thread depths of commercially available dental implants affect primary stability in low-density D3 bone. Materials and Methods: An in vitro study was carried out between February 2024 and March 2024. Twenty-four dental implants were divided into four groups (six implants each) according to their thread depths (Group A: 4 mm, Group B: 4.5 mm, Group C: 5 mm, Group D: 5.5 mm) and were inserted in D3-type artificial bone blocks. The main outcome variables were the IT and the Implant Stability Quotient (ISQ) measured in four different areas of the implant (buccal, lingual, mesial, and distal) with an Osstel® ISQ reader. Descriptive and inferential analyses of the data were performed, and the significance value was set at 5%. Results: A total of 24 implants were analyzed. The highest IT values were obtained in Group D, with a mean of 54.03 Ncm (standard deviation (SD) = 8.99), while the lowest measurements were observed in Group A (mean = 25.12; SD: 2.96 N.cm). The mean ISQ values were consistently higher in Group D for each analyzed area, with a mean of 70.13 N.cm (SD = 1.12). Conclusions: Taking into consideration the limitations of this in vitro study, greater thread depths seem to increase the primary stability of dental implants placed in soft bone. Furthermore, a positive correlation was observed between all IT and ISQ values, regardless of the thread depth.

The Importance of Bone Quality Diagnostics in Preventing Displacement of Dental Implants within the Mandibular Body: A Case Report

Abstract Among the immediate complications that can occur after dental implant placement, accidental displacement within the medullary spaces of the mandibular body is a rare clinical situation. This case report describes implant displacements in the posterior mandibular region and emphasizes the importance of assessing bone density and mandibular medullary patterns prior to implant placement according to a new classification by Lekholm and Zarb modified by Rosas et al. The case reports reported three implant displacements in type II bone of the mandibular body, as classified by Lekholm and Zarb. Following the complication, the bone was reclassified as II-B according to the modification by Rosas et al. The implants were extracted from three female patients aged from 37 to 75 years, with only one having a medical history. All complications were treated and resolved without any alteration after implant removal. To reduce the risk of intraoperative complications that affect the primary stability of dental implants, such as implant migration in the mandibular body, it is important to consider factors that may affect the mechanical locking of the implant at the time of placement, such as the pattern and thickness of the bony trabeculae and the size of the medullary spaces in areas of anatomical risk. For this purpose, we recommend using the modified Lekholm and Zarb classification by Rosas et al. This classification considers the trabecular bone biotype, which helps in planning the surgical approach procedure and establishing a regenerative protocol to minimize the risk of complications with the inferior dental nerve.

A Comparison of Different Implant Site Preparation Techniques in Low-Density Bone: An Ex-Vivo Study.

Osseointegration is considered a prerequisite for the long-term success of dental implants, and many researchers have considered the stability of the implant when placed in the bone. Many techniques include undersized drilling, densifying burs, magnetic mallets, and expanders. These methods have led to higher initial insertion torque values. The present study aims to evaluate the effectiveness of expanders, densifying burs, and magnetic mallet methods for preparing the implant site in low-density bone and compare them in terms of achieving good initial implant stability. The present study was conducted in an ex vivo animal model using bovine rib bones. This study was performed on 20 bovine ribs; each rib had four implant site preparations divided into four groups according to the drilling method: a control group of the conventional technique (n=20), the expanders group (n=20), the densification burs group (n=20), and the magnetic mallet group (n=20). The measured values were Primary Insertion Torque and Implant Stability Quotient (ISQ). The highest average insertion torque was in the magnetic Mallet group, where the average was 43.75 N/cm2, followed by the burs group, where the average was 43.00 N/cm2, then the expanders group with an average of 32.80 N/cm2, then the conventional preparation group with 19.30 N/cm2as the lowest average among the study groups. The highest ISQ mean was in the burs group, where the mean was 80.30, followed by the magnetic Mallet group, where the mean was 80.20, then the expanders group with a mean of 68.90, then the conventional preparation group with 50.10 as the lowest mean among the study groups. Within the limitation of this study, we conclude that all methods used were better than conventional preparation in both ISQ and insertion torque, with the magnetic mallet group outperforming the insertion torque and the Densah burs outperforming the ISQ.

The effect of compressive force in bone tissue induced by implants of different primary stabilities on macrophage polarization and bone regeneration

Dental implants with different primary stabilities give rise to distinct stress distributions at the implant-bone interface after placement and exert mechanical force on the cells in the bone tissue. This study aimed to investigate whether the mechanical forces in peri-implant bone participate in the body’s immune response and influence macrophage polarization. Therefore, an in vivo rat implantation model with different primary implant stabilities was established. The osteoimmune response and macrophage polarization were investigated, and the osseointegration of the implants was evaluated. In an in vitro experiment, an external compressive force was applied to RAW264.7 cells, and the polarization phenotype was observed. MC3T3-E1 cells were cultured in macrophage-conditioned medium to investigate the regulatory effect of the macrophage-secreted cytokines on the osteogenic differentiation of osteoblasts. In vivo experimental results indicated that the primary stability of implants is positively correlated with the mechanical force. The osteoimmune response was significantly amplified by compressive force generated from implants. This compressive force first induced both M1 and M2 macrophage polarization and then accelerated the progression of the transition to M2 macrophages in the bone repair phase. In vitro, compressive force significantly upregulated the M1 and M2 macrophage polarization. In addition, the suppressive effect of macrophages on the osteogenesis of MC3T3 cells was relieved by cytokines secreted by macrophages under compressive force loading, which promoted their osteogenesis. Overall, these results clarify that compressive force from different primary stabilities is an important influencing factor regulating the osteoimmunne response and macrophage polarization in addition to maintaining the implant.

Comparison of 5-year cup and stem migration between ceramic-on-ceramic and ceramic-on-polyethylene bearing in press-fit total hip arthroplasty: a randomised controlled trial using radiostereometric analysis.

The inelasticity of ceramic bearings might affect primary stability and migration of implants in press-fit total hip arthroplasty (THA). This randomised controlled trial compares migration patterns of the uncemented Delta-TT cup and H-MAX S stem between ceramic and polyethylene liners, up to 5 years follow-up. Patients receiving primary press-fit THA were randomly allocated to a ceramic (n = 28) or polyethylene (n = 25) liner. Migration was measured using model-based radiostereometric analysis (RSA) at baseline and 1.5, 3, 6, 12, 24 and 60 months postoperatively and compared between groups using mixed models statistical analysis. The focus of this study is on the 2- to 5-year migration of the Delta-TT cup and migration during complete follow-up of the H-MAX S stem up to 5-years. At 5-year follow-up, mean (95% CI) proximal cup translation was 0.56 (0.37-0.74) mm in ceramic and 0.58 (0.25-0.90) mm in polyethylene (p = 0.729). The mean change in adduction was 1.05° (0.27-1.82°) in ceramic and 0.78° (-0.16-1.71°) in polyethylene. Mixed modelling showed that all between-group effects were ⩽0.20 mm for translation and ⩽0.22° for rotation at 5 years postoperatively (p ⩾ 0.23). Mean cup migration between 2 and 5 years was limited (all parameters <0.17 mm and <0.30°). At 5-year follow-up, mean stem subsidence was 2.09 mm (0.89-3.29 mm) in ceramic and 2.55 (0.97-4.12) mm in polyethylene. The mean change in internal rotation was 3.69° (1.98-5.40°) in ceramic and 4.01° (2.20-5.81°) in polyethylene. Most stem migration occurred up to 1.5 months, stabilising afterwards. All between-group effects were ⩽0.75 mm for translations and ⩽1.41° for rotations (p ⩾ 0.26). 5-year migration patterns of press-fit cups and stems were similar between ceramic and polyethylene liners. The Delta-TT cup and H-MAX S stem showed secondary stabilisation and remained stable up to 5 years in both groups, which is promising for long-term survival with both liner types. ClinicalTrials.gov (NCT03093038).

Homogenized finite element simulations can predict the primary stability of dental implants in human jawbone

Adequate primary stability is a pre-requisite for the osseointegration and long-term success of dental implants. Primary stability depends essentially on the bone mechanical integrity at the implantation site. Clinically, a qualitative evaluation can be made on medical images, but finite element (FE) simulations can assess the primary stability of a bone-implant construct quantitatively based on high-resolution CT images. However, FE models lack experimental validation on clinically relevant bone anatomy. The aim of this study is to validate such an FE model on human jawbones. Forty-seven bone biopsies were extracted from human cadaveric jawbones. Dental implants of two sizes (Ø3.5 mm and Ø4.0 mm) were inserted and the constructs were subjected to a quasi-static bending-compression loading protocol. Those mechanical tests were replicated with sample-specific non-linear homogenized FE models. Bone was modeled with an elastoplastic constitutive law that included damage. Density-based material properties were mapped based on μCT images of the bone samples. The experimental ultimate load was better predicted by FE (R2 = 0.83) than by peri-implant bone density (R2 = 0.54). Unlike bone density, the simulations were also able to capture the effect of implant diameter. The primary stability of a dental implant in human jawbones can be predicted quantitatively with FE simulations. This method may be used for improving the design and insertion protocols of dental implants.

The Effect of Osteotomy Preparation Technique and Implant Diameter on Primary Stability and Bone-implant Interface of Short Implants (6 mm).

To evaluate the effect of osteotomy preparation technique and implant diameter on primary stability and bone-implant interface of short implants (6mm), when placed in bone with high degree of cancellous content. 90 short (S) implants (6 mm) divided in nine groups based on width (Narrow 4.2 mm, Regular 4.8 mm, Wide 5.4 mm) (N,R,W) and osteotomy preparation (Standard, Osteotome, Osseodensification) (ST, OT, OD) and placed in porcine tibia plateau bone samples: Group SN-ST; Group SN-OT; Group SN-OD; Group SRST; Group SR-OT; Group SR-OD; Group SW-ST; Group SW-OT and Group SW-OD. Insertion torque and Implant Stability Quotient (ISQ) were measured. Four implants from each group SNST, SN-OT, SN-OD were evaluated histomorphometrically. Insertion torque was significantly higher for implants of Group SW-OD compared to Group SW-ST (50.00 ±14.14 Ncm vs 28.00 ±10.85 Ncm, p&#61; 0.005) and Group SW-OT compared to Group SW-ST (46.87 ±17.10 Ncm vs 28.00 ±10.85 Ncm, p&#61;0.026). Insertion torque was significantly higher for implants of Group SW-OD compared to Group SN-OD (50.00 ±14.14 Ncm vs 31.5 ±15.82 Ncm, p&#61;0.04). No significant differences were observed for the percentage of bone, marrow space and connective tissue in contact to the implant surface between studied groups. Osteotomy preparation technique at sites with high degree of cancellous content can influence the implant insertion torque for short and wide implants (5.4x6mm). Implant width can influence the insertion torque of short implants placed with the osseodensification technique.

Primary Stability and Fracture Resistance of Zirconia and Titanium Implants: A Paired Comparative In Vitro Study.

Compare Neodent Zi® zirconia implants' insertion torque (IT) and removal torque (RT) with Neodent Alvim® titanium. Measure the maximum torque supported by the zirconia implant until its fracture (MT) and the maximum torque sustained by the assembler of this implant (MTA) until its fracture. In this in-vitro study twenty four implants were used. Two groups of implants with the same macrogeometry and from the same manufacturer were compared, Zirconia (n=12) and Titanium (n=12). Implant bed preparations were completed in bovine ribs following a standardized drilling protocol. Then, the insertion torque (IT), removal torque (RT), maximum torque to fracture (MT) and maximum torque to fracture of the assembler (MTA) were completed using a calibrated torque meter. Data was presented using descriptive statistics including means, standard deviations (SD), medians, and quartiles. The Shapiro-Wilk test was used to verify data normality and the Wilcoxon test was used to evaluate differences between groups. Statistical significance was established as p < 0.05. Zirconia implants showed: IT 89.33 ± 31.18 Ncm and RT 84.89 ± 32.92 Ncm. Titanium implants showed: IT 77.58 ± 28.96 Ncm and RT 76.75 ± 31.29 Ncm without significant differences (p>0.05). In relation to fracture under rotational force, the zirconia implants fractured at 106.17 ± 22.54 Ncm, and the implant assembly fractured at 84.00 ±13.14 Ncm. Neodent Zi® implants showed stability but lower fracture torque than Alvim® titanium. As the fracture values of the assembler were significantly lower than the fracture values of the zirconia implants, it can be stated that, as recommended by the manufacturer, they act as a safety measure during installation.

Osseodensification: An Innovative Technique With Manifold Gains.

Prosthodontics, which isremovable and fixed, is the branch dealing with the replacement of missing teeth. Implant therapy is the popular treatment modality and commonly preferred treatment option by many patients and clinicians for missing teeth in recent years. Primary implant stability (PIS) is one of the crucial factors for osseointegration. It has been considered a crucial factor in the success of implants. Moreover, several factors influence PIS. On the other hand, both secondary implant stability and osseointegrationare influenced by the PIS. Bone density, bone volume, bone-to-implant contact, and other factors that enhance or degrade the primary stability. Certain host sites such as the maxillary posterior region demand more dense bone to achieve desired results as they are the low-density areas of the jaw. So, a new promising and growing innovative concept of osseodensification (OD) offers a great solution with multiple benefits and desirable results. This review article aims to enlighten the multiple benefits of OD technique and their mechanism of action.

Preservation of Socket for Immediate Dental Implants in Aesthetic Zone from Upper Jaw: Aesthetic Approach-Case Report

Ensuring optimal aesthetic outcomes in dental implant cases within the maxillary anterior area requires careful consideration of socket preservation and atraumatic tooth extraction. These factors play a crucial role in achieving successful and aesthetically pleasing treatments. The objective of this study is to present a series of clinical cases involving dental extractions of anterior maxillary teeth with a poor prognosis. This study highlights the importance of socket preservation and atraumatic tooth extraction in ensuring optimal aesthetic results in dental implant cases within the maxillary anterior area. In these cases, a two-armed lever technique was planned for atraumatic alveolar preservation during the extraction process.Following the tooth extraction, the fresh socket was reclassified, and dental implants were subsequently placed using a modified drilling technique in certain cases. The authors assessed the primary stability of the implants, while in other cases, bone regeneration procedures were performed. The presented clinical cases demonstrate the successful implementation of the two-armed lever technique for atraumatic alveolar preservation, leading to favorable outcomes in terms of primary implant stability and bone preservation. Techniques for bone preservation after tooth extraction aim to minimize post-extraction bone resorption. By implementing appropriate protocols, such as the concept of the dual zone and the two-armed lever technique, successful outcomes can be achieved in terms of both aesthetics and preservation of the alveolar bone.

Primary Implant Stability: A Crucial Pillar in Implantology

Primary Implant Stability: A Crucial Pillar in Implantology

Primary Stability of Implants Inserted into Polyurethane Blocks: Micro-CT and Analysis In Vitro.

A total of 150 implant sites were prepared in rigid polyurethane blocks to simulate two distinct bone densities of 15 pounds per cubic foot (PCF) and 30 PCF, with a 1-mm-thick simulated cortex. The implant sites were equally distributed among piezoelectric surgery (PES), traditional drills (TD), and black ruby magnetic mallet inserts (MM). Two methods have been employed to evaluate the implant's primary stability, Osstell and micro-tomography. In the present study, we observed significant variations in the implant stability quotient (ISQ) values. More precisely, our findings indicate that the ISQ values were generally higher for 30 PCF compared to 15 PCF. In terms of the preparation technique, PES exhibited the greatest ISQ values, followed by MM, and finally TD. These findings corresponded for both bone densities of 30 PCF (PES 75.6 ± 1.73, MM 69.8 ± 1.91, and TD 65.8 ± 1.91) and 15 PCF (PES 72.3 ± 1.63, MM 62.4 ± 1.77, and TD 60.6 ± 1.81). By utilizing Micro-CT scans, we were able to determine the ratio of the implant occupation to the preparation site. Furthermore, we could calculate the maximum distance between the implant and the wall of the preparation site. The findings demonstrated that PES had a higher ratio of implant to preparation site occupation, followed by TD, and then the MM, at a bone density of 30 PCF (PES 96 ± 1.95, TD 94 ± 1.88, and MM 90.3 ± 2.11). Nevertheless, there were no statistically significant differences in the occupation ratio among these three approaches in the bone density of 15 PCF (PES 89.6 ± 1.22, TD 90 ± 1.31, and MM 88.4 ± 1.17). Regarding the maximum gap between the implant and the site preparation, the smallest gaps were seen when TD were used, followed by MM, and finally by PES, either in a bone density 15 PCF (PES 318 ± 21, TD 238 ± 17, and MM 301 ± 20 μm) or in a bone density 30 PCF (PES 299 ± 20, TD 221 ± 16, and MM 281 ± 19 μm). A statistical analysis using ANOVA revealed these differences to be significant, with p-values of < 0.05. The outcomes of this study indicate that employing the PES technique and osteo-densification with MM during implant insertion may enhance the primary stability and increase the possibility of early implant loading.

Evaluation of the Correlation Between the Structural Parameters of Trabecular Bone in CBCT and the Primary Stability of Dental Implants.

To investigate the relationship between the structural parameters of trabecular bone obtained from CBCT imaging and the primary stability of dental implants. Sixty patients underwent implant placement followed by primary stability evaluation via measurement of the insertion torque (IT) and the implant stability quotient (ISQ). Gray values (GV) and the fractal dimension (FD) were also measured using pretreatment CBCT images. FD values showed a positive and significant relationship with ISQ and IT values (P = .017 and P = .004, respectively). Additionally, there was a positive and significant correlation between GV and IT (P = .004) as well as between GV and ISQ (P = .010). FD and GV showed a considerable difference between the maxillary and mandibular jaws and were higher in the mandible. Only FD was significantly different between men and women and was higher in men. In the two age groups (older and younger than 45 years), only GV was considerably higher in people older than 45 (P < .05). Both fractal dimension and gray values obtained from CBCT are efficient methods for predicting the primary stability of the implant due to their relationship with ISQ and IT values.

Measurement of Implant Insertion Torque in Intentionally Undersized Osteotomy Site Preparation in the Posterior Maxilla: A Prospective Clinical Study.

Achieving adequate primary stability for dental implants in the posterior maxilla is challenging due to the area's low bone density and fine trabecular bone. Low primary implant stability can compromise the long-term success of the implant. This study aims to evaluate the effect of intentionally undersized osteotomy sites on the insertion torque of implants placed in type 4 bone density in the posterior maxilla, regardless of the surgeon's tactile sense of the bone density. The conventional implant placement technique was performed in the posterior maxilla by intentionally omitting the last drill of the recommended drilling sequence protocol. The insertion torque was measured using an integrated surgical motor software. The study included 72 implants in patients of both genders and different age groups. The retrieved samples were divided into four groups, with insertion torque ranging from 11 Ncm to 48 Ncm. The mean insertion torque was 26.51 ± 0.18 Ncm for all cases (P = .001). No significant difference was found in the mean insertion torque between different age groups (26.51 ± 2.845, P = .84). However, a significant difference was observed between male and female cases (P = .84). Most implant insertion torque measurements vary significantly between cases in the intentionally underprepared posterior maxillary osteotomy site. The last drill should be omitted for all preparations of the posterior maxillary implant sites. Intentionally minimizing the osteotomy site is recommended for all posterior maxillary implant cases.

Critical loss of primary implant stability in osteosynthesis locking screws under cyclic overloading

Primary implant stability, which refers to the stability of the implant during the initial healing period is a crucial factor in determining the long-term success of the implant and lays the foundation for secondary implant stability achieved through osseointegration. Factors affecting primary stability include implant design, surgical technique, and patient-specific factors like bone quality and morphology. In vivo, the cyclic nature of anatomical loading puts osteosynthesis locking screws under dynamic loads, which can lead to the formation of micro cracks and defects that slowly degrade the mechanical connection between the bone and screw, thus compromising the initial stability and secondary stability of the implant. Monotonic quasi-static loading used for testing the holding capacity of implanted screws is not well suited to capture this behavior since it cannot capture the progressive deterioration of peri‑implant bone at small displacements. In order to address this issue, this study aims to determine a critical point of loss of primary implant stability in osteosynthesis locking screws under cyclic overloading by investigating the evolution of damage, dissipated energy, and permanent deformation. A custom-made test setup was used to test implanted 2.5 mm locking screws under cyclic overloading test. For each loading cycle, maximum forces and displacement were recorded as well as initial and final cycle displacements and used to calculate damage and energy dissipation evolution. The results of this study demonstrate that for axial, shear, and mixed loading significant damage and energy dissipation can be observed at approximately 20 % of the failure force. Additionally, at this load level, permanent deformations on the screw-bone interface were found to be in the range of 50 to 150 mm which promotes osseointegration and secondary implant stability. This research can assist surgeons in making informed preoperative decisions by providing a better understanding of the critical point of loss of primary implant stability, thus improving the long-term success of the implant and overall patient satisfaction.

First-in-Human Pilot Study to Assess Methodology for Using a Mineral-Organic Bone Adhesive for Optimization of Primary Stability and Implant Success for Implants Glued into Immediate Extraction Sockets and Immediately Temporized: Pilot Study.

To assess the handling properties and clinical function of a new class of material, a so-called mineral-organic bone adhesive (Tetranite; TN), which as yet has no precedent in orthopedic or oral and maxillofacial surgery, for clinically unstable implants placed in immediate extraction sockets and immediately temporized in the anterior maxilla. A cohort of up to 15 patients requiring between one and four immediate dental implants placed into maxillary extraction sockets from canine to canine were eligible for inclusion. Implants had to be unstable with an insertion torque of < 15 Ncm. Implants were then stabilized using TN, which was allowed to set before reassessing stability using both torque and resonance frequency measurements. Implant stability quotients (ISQs) taken after TN setting were compared to ISQs taken prior to its application, and the implants had to demonstrate resistance to a forward torque of 20 Ncm to be considered stable. ISQs were monitored at 1 week and 1, 3, 7, and 12 months postplacement. In addition, peri-implant tissue health was monitored, adverse events were recorded, and implant success was determined at 1 year postplacement. Eleven patients received a total of 14 implants. Three out of the first six implants failed within 1 month (50%), and thus a protocol amendment was made to remove steps considered potentially destructive to the bonding process. As a result of these amendments, only one further failure was experienced for the next eight implants placed (12.5%). Mean ISQ data averaged for buccolingual and mesiodistal measurements demonstrated a baseline value before TN application of 59.1 Ncm (SD: ± 9.7; range: 40.5 to 73.0). After final setting of the TN, mean ISQ measured 71.9 Ncm (± 6.5; 56.0 to 80.0). At 3 months, just prior to restoration placement, mean ISQ measured 71.0 Ncm (± 6.6; 57.0 to 78.0). Thereafter, the mean ISQ continued to increase at both the 7- and 12-month follow-ups with scores of 78.9 (± 4.6; 72.0 to 84.5) and 80.3 (± 3.8; 74.5 to 85.0), respectively. The surviving 10 implants went on to be fully restored and remained in function beyond the end of the study period to yield a final success rate of 71.4%. The purpose of a first-in-human study is to demonstrate an extrapolation of preclinical data into the controlled human clinical arena. It is an opportunity to learn what does and does not translate well from experimental data. In that regard, the current pilot study can be deemed a complete success. The implant survival rate of 71.4%, while disappointing, should be considered in light of the protocol amendments identified, the user handling experience learned, and the opportunity to modify the material to better perform in the human patient, as all represent important lessons learned. The notable increase in ISQ sheds light on the nature by which the glue was substituted for bone to yield a stable implant by the end of the study period.

Primary stability with osseodensification drilling of dental implants in the posterior maxilla region in humans: A systematic review.

Currently, a new non-subtractive drilling technique, called osseodensification (OD), has been developed. It involves using specially designed drills with large negative cutting angles that rotate counterclockwise, causing expansion through plastic bone deformation, thus compacting the autologous bone to the osteotomy walls, which improves the primary stability of the implant.The present systematic review aimed to determine whether the OD technique can increase the primary stability of dental implants in the posterior maxilla region as compared to the conventional drilling (CD) technique.Five databases were searched up to June 30, 2022. The inclusion criteria embraced observational clinical studies, randomized and non-randomized controlled trials, human studies in vivo, comparing OD and CD, with the measurement of the primary stability of implants in the posterior maxilla region by means of the implant stability quotient (ISQ). The tools used to assess the risk of bias were RoB 2 and the NewcastleOttawa Scale (NOS).Seven articles met the inclusion criteria, with 4 classified as having a low risk of bias and 3 with a moderate risk of bias. The OD technique consistently demonstrated an average ISQ value of 73 KHz across all studies, whereas CD yielded an average value of 58.49 kHz (p < 0.001 for 5 articles).It can be concluded that in comparison with CD, OD improves primary stability at baseline in low-density bone, such as the maxilla.