Primary Stability Of Dental Implants Research Articles

Effect of the Implant Macro-Design on Primary Stability: A Randomized Clinical Trial

Aim of the study: Comparing the impact of two different implant macro-designs on the primary stability. Material and methods: Patients received implants in the lower posterior jaw (bone type II and III). Two different macro-design implants were inserted randomly in accordance with a conventional drilling protocol, the first one is the hybrid self-tapping implant: Straumann® bone level BL and the second one is tapered self-tapping implant: Straumann® bone level tapered BLT.16 implants (3.3 and 4.1 mm diameter, length between 8 and 10 mm) of each of the two above-mentioned implants were used. The assessment of the primary stability of each implant design was carried out by using two methods, recording the maximum insertion torque IT (DTA device) and recording the implant stability quotient ISQ using the resonance frequency analysis RFA (with the Osstell device). Results: Within the limitation of the present study, in all bone types, BLT implants showed significantly higher mean insertion torque IT when compared to BL with respectively 46.67±6.85 Ncm for BLT implants and 35.77±6.72 Ncm for BL implants (p=0.01 as per the Anova test), and higher mean ISQ with respectively 77.15±5.16 and 70.74±4.83. (p=0.01 as per the Anova test). Conclusion: In type II and III bone, the tapered self-tapping implant (Straumann® BLT) statistically showed better primary stability when compared to hybrid self-tapping implant: Straumann® bone level BL. Within the limitations of the present study, it can be concluded that the implant Macro-Design might be considered as a reliable parameter to achieve acceptable primary stability of dental implants in areas with low bone density. In the present study, the two methods used to assess the primary stability of the different macro-designs, torque assessment and the resonance frequency analysis RFA, showed a weak correlation. The macro-geometry is basically made to satisfy the needs in some critical bone situations and in immediate loading protocol.

Is Resonance Frequency Analysis a Reliable Evaluation for Primary Stability of Implants Without Apical Contact?

The primary stability of dental implants is one of the most crucial factors for providing long-term success of osseointegration. Vertical deficiencies, such as those due to maxillary sinus pneumatization, may cause a severe vertical limitation to residual bone height. This study aimed to examine the primary stabilization of implants without apical contacts. Eighty bone-level implants (4.1-mm diameter/10-mm length) were placed into polyurethane test blocks without apical contacts. According to coronal bone-to-implant contact, groups were set as 4, 6, 8, and 10 mm, respectively. Resonance frequency analysis (RFA) using a SmartPeg was performed separately toward the transversal and horizontal axes by two independent researchers. Data were statistically compared for interobserver and among groups. Interobserver reliability varied from moderate to excellent (intraclass correlation coefficient [ICC]: 0.629 to 0.985). There were no significant differences among the 6 mm, 8 mm, and 10 mm groups, although the 4 mm group showed the significantly lowest stability (P < .001). Transversal and longitudinal measurements of the same groups did not show a parallel correlation statistically. RFA values may be affected by the finger torque in tightening of the SmartPeg among different researchers. Fully placed implants did not significantly show the highest stability among various apically contactless groups. Consequently, RFA should not be used alone to evaluate primary stability for implants without an apical contact.

EFFECTIVENESS OF DENTAL IMPLANTATION WITH IMMEDIATE LOADING WHEN REPLACING FRONTAL DENTITION DEFECTS

Dental implantation, viewed as an independent research-based method used to treat patients with partial and complete adentia, has a special place among the major dental specialties. There are surgical algorithms and established methods for using dental implants available. The classical two-stage implantation protocol with delayed loading is considered the most reliable and predictable, featuring the lowest complication rate. The increased interest in direct dental implantation with immediate loading can be accounted for by psycho-emotional factors, accelerated implant osseointegration, better functional and aesthetic results, prevention of alveolar process bone atrophy, as well as reduced volume of surgical and orthopedic interventions. The stability of dental implants after direct implantation and immediate loading has been found to match the stability of implants after employing a two-stage technique. The primary stability of dental implants installed directly into the hole of the removed tooth on the anterior mandible is due to a small volume of spongy substance at a significantly thick cortical layer, possible installation of an implant with a length exceeding the length of the tooth root, the availability of a proper keratinized gum zone, as well as the removal from occlusion temporary structures on implants.

Possibilities and prospects for experimental and clinical instrumentation techniques for determining the primary stability of dental implants in comparative analysis

The high primary stability of dental implants provides a favorable prognosis for orthopedic treatment with implant-supported structures. The importance of assessing the stability and the bone tissue surrounding the implant as a whole is due to the fact that the process of osseointegration is a structural and functional connection between the bone and the loaded surface of the implant. Determination of the dynamics of the stability of dental implants allows timely monitoring of unpredictable changes at the stages of osseointegration and remodeling of bone tissue around the implant. Currently, in addition to clinical and radiation diagnostic methods, there are generally recognized by clinicians frequency resonance analysis and periotestometry. However, there are some scientific discrepancies indicating the lack of objectivity of these methods and the impossibility of their full-fledged application without the support of radiation and clinical diagnostic methods. In addition to these methods, there are many experimental and less common methods in clinical practice for assessing the primary stability of implants, but with reasonable objectivity. Thus, the reasons are given that for a full assessment of the relationship between the efforts exerted on implants and their movements in the space of bone tissue, devices are needed that reflect the stability and density of the contact of the implant with bone tissue in physical quantities. In particular, methods based on lasers, sound, quantitative ultrasound, and others have found experimental practical application. The ultrasound method of assessing the primary stability of the implant is estimated as the most promising, since it allows you to demonstrate the results of studies in certain physical quantities, as well as to compare these results with histomorphological indicators of osseointegration of dental implants.

Evaluation of bone density by cone-beam computed tomography and its relationship with primary stability of dental implants

One of the critical factors determining the success of dental implants is primary stability. This study aimed to determine the density of jawbones in the implant candidate sites via cone-beam computed tomography (CBCT) and its correlation with the values obtained from resonance frequency analysis during surgery. In this descriptive-analytic study seventeen implant sites requiring implant placement were selected. Impressions were sent to the laboratory to construct a surgical guide via the stereolithographic method. An electronic surgery was performed on the chosen implant sites according to each patient's CBCT information entered into the Kaveh surgical guide software. The bone density of the target areas was calculated using the gray value (voxel value). After preparing the final osteotomy, an implant was installed in the area according to the manufacture's recommendation. The relevant Osstell® SmartPeg was selected and installed on the implant body to determine the primary stability. Kolmogorov-Smirnov test and the correlation pearson correlation statistical test. used for statistical analyze. P value amounts < 0.05 was considered significant. The mean and standard deviation of the gray scale in this study were 563.7 ± 218.8 and 65.3 ± 7.7 implant stability quotient (ISQ) respectively. The correlation between gray scale and ISQ was evaluated by the Pearson correlation test, and the results indicated a strong correlation between the two variables. The voxel value and primary stability had a normal distribution and strong correlation. In other words, the gray scale determined by CBCT imaging techniques at the proposed implant site could be used to assess the bone density before the surgery.

Relationship between the bone density estimated by cone-beam computed tomography and the primary stability of dental implants

It enables more accurate three-dimensional evaluation of anatomic structures and directly measures the bone density. The density of the bone is usually expressed in Hounsfield units (HU)1 which is a parameter that provide the most important details about the available bone. A total of 18 fresh femoral heads of swine were taken for the study. The adjacent soft tissues have been removed completely and the surfaces of the bone blocks were made flat using a carbide bur. The thickness of each block was cross-checked using precision vernier calipers and maintained at more than 10 mm. Using the ISQ values as the independent variable, the standardized partial regression coefficients of the thickness of the cortical bone, the voxel value, and the length of the implant were 0.328, 0.306, and 0.422 respectively, all of them are significant variables. It has been observed that there was a correlation between the thickness of the cortical bone or the voxel values obtained from the CBCT scanning images prior to the implant placement and the implant stabilities.

Regional differences in microarchitecture and mineralization of the atrophic edentulous mandible: A microcomputed tomography study

ObjectiveThe aim of the present study was to assess mineralization and trabecular microarchitecture in atrophic edentulous mandibles and to identify regional differences and relations with the extent of resorption. MethodsCortical and trabecular bone volumes in anterior, premolar and molar regions of 10 edentulous cadaveric mandibles (5 males and 5 females; mean age ± SD: 85.4 ± 8.3 years) were assessed by microcomputed tomography. Mandibular height and Cawood & Howell classes were recorded. Concerning trabecular volumes, bone mineral density (BMD), bone volume fraction, trabecular tissue volume fraction, connectivity density, trabecular number, trabecular thickness, trabecular separation, degree of anisotropy, and structural model index were measured; concerning cortical volumes porosity, BMD and cortical thickness were measured. ResultsIn molar regions, the bone volume fraction and trabecular number were lower, whereas trabecular separation, degree of anisotropy and cortical BMD were higher compared to anterior regions. In premolar regions, mandibular height correlated negatively with trabecular number (Spearman’s correlation r = 0.73, p = 0.017) and connectivity density (Spearman’s correlation r = 0.82, p = 0.004), and correlated positively with trabecular separation (Spearman’s correlation r = − 0.65, p = 0.04). Cortical BMD was higher at bucco-inferior cortex of molar and inferior border of premolar region and lower at anterior cranial buccal and lingual surface. ConclusionsIn the premolar region, increased resorption coincides with local impairment of trabecular bone quality. Cortical bone BMD is higher in areas with highest strains and lower in areas with most mandibular resorption. Trabecular bone volume and quality is superior in the anterior region of the edentulous mandible, which might explain improved primary stability of dental implants in this region.

FEATURES OF TROPHISM OF BONE TISSUE AFTER THE INSTALLATION OF DENTAL IMPLANTS

Relevance. The most important condition for a successful result of dental implantation is high-quality osseointegration of dental implants. In the literature, the issue of the quality of osseointegration is widely covered, which directly depends on the primary stability of dental implants. In the area of bone tissue remodeling, surrounding the installed dental implants, there are permanent processes of bone resorption and its restoration [1][2].The aim is to reveal the reactivity of alkaline phosphatase and osteocalcin in the biological fluid (saliva) in patients after dental implants.Materials and methods. The collection and analysis of clinical material was carried out on the basis of the Clinics of the Samara State Medical University of the Ministry of Health of Russia. Dental implantation surgery was performed in 184 patients aged 32 to 65 years. The gender ratio was 2:3 (40 men and 60 women). The teeth were lost due to poor oral hygiene and caries complications.Results and discussion. At the time of admission of patients to the department of the Department of Prosthetic Dentistry of the Clinics of the Samara State Medical University of the Ministry of Health of Russia, the bulk of the patients had a low hygienic status. The OHI-S index averaged 2.74 ± 0.33 conventional units. (control – 0.50 ± 0.07 c.u.). In order to reduce the negative influence of microorganisms in the supra- and subgingival dental deposits, all patients underwent professional oral hygiene, as well as antimicrobial therapy. At the time of installation of dental implants, the average OHI-S and Müllemann-Cowell index was 0.72 ± 0.06 and 0.57 ± 0.06 conventional units, respectively.Conclusions. 1. The increase in the titer of alkaline phosphatase and osteocalcin during dental implantation is not statistically significant. 2. TCRF in the oral fluid (saliva) exhibits maximum activity by the 14th day, exceeding the initial three times. This indicator remains at an increased level in the period up to six months from the beginning of the operation. 3. Revealing the values of the TRKF titer after the operation of dental implantation is advisable to use as an assessment of the state of trophic processes occurring in the bone tissue.

FEATURES OF TROPHISM OF BONE TISSUE AFTER THE INSTALLATION OF DENTAL IMPLANTS

Relevance. The most important condition for a successful result of dental implantation is high-quality osseointegration of dental implants. In the literature, the issue of the quality of osseointegration is widely covered, which directly depends on the primary stability of dental implants. In the area of bone tissue remodeling, surrounding the installed dental implants, there are permanent processes of bone resorption and its restoration [1, 2]. The aim is to reveal the reactivity of alkaline phosphatase and osteocalcin in the biological fluid (saliva) in patients after dental implants. Materials and methods. The collection and analysis of clinical material was carried out on the basis of the Clinics of the Samara State Medical University of the Ministry of Health of Russia. Dental implantation surgery was performed in 184 patients aged 32 to 65 years. The gender ratio was 2:3 (40 men and 60 women). The teeth were lost due to poor oral hygiene and caries complications. Results and discussion . At the time of admission of patients to the department of the Department of Prosthetic Dentistry of the Clinics of the Samara State Medical University of the Ministry of Health of Russia, the bulk of the patients had a low hygienic status. The OHI-S index averaged 2.74 ± 0.33 conventional units. (control – 0.50 ± 0.07 c.u.). In order to reduce the negative influence of microorganisms in the supra- and subgingival dental deposits, all patients underwent professional oral hygiene, as well as antimicrobial therapy. At the time of installation of dental implants, the average OHI-S and M ü llemann-Cowell index was 0.72 ± 0.06 and 0.57 ± 0.06 conventional units, respectively. Conclusions. 1. The increase in the titer of alkaline phosphatase and osteocalcin during dental implantation is not statistically significant. 2. TCRF in the oral fluid (saliva) exhibits maximum activity by the 14th day, exceeding the initial three times. This indicator remains at an increased level in the period up to six months from the beginning of the operation. 3. Revealing the values of the TRKF titer after the operation of dental implantation is advisable to use as an assessment of the state of trophic processes occurring in the bone tissue.

The correlation of CBCT analysis derived bone density parameters with primary implant stability - a clinical study

Background/Aim. There are numerous studies on the usefulness of computed tomography (CT) in the assessment of the bone volume and morphology and on the relationship between CT and primary implant stability. But there is the scarcity of data about the correlation between bone density and the value of primary implant stability. The aim of this study was to examine the correlation of cone beam CT (CBCT) analysis derived bone density with primary stability value. Methods. Clinical prospective experimental study was conducted on 38 healthy patients missing one tooth in the lateral region. It was planned to install Bredent Blue Sky Narrow self-taping dental implants with dimensions 3.5 ? 10 mm. During preoperative preparation, a CBCT scan was performed on Planmeca apparatus, followed by preimplantation measurements and planning in the CBCT apparatus software (Romexis). The mean value of the average bone density was automatically generated and expressed in Hounsfield units (HU). Upon implant placement, we performed measurements of the primary implant stability using Osstell apparatus. Results. Of the 38 patients included in the study, there were 68.4% male patients and 31.6% female patients. The arithmetic mean of the measured bone density of all subjects in the study amounted to 536.2 HU. The arithmetic mean of dental implant primary stability for all subjects in the study was 68.7 ISQ. There was a statistically significant strong positive connection between HU and ISQ (r = 0.744, p &lt; 0.001). Higher HU values were connected to higher ISQ values. In the multivariate linear regression model, statistically significant predictors of higher ISQ values: males (B = 4.669; p = 0.047) and higher HU values (B = 0.032; p &lt; 0.001). Conclusion. In our clinical study, there was a statistically significant strong positive correlation between the bone density expressed in HU units, measured in the software of the CBCT device and the primary stability of dental implants expressed in ISQ units.

Applicability of cone beam computed tomography gray values for estimation of primary stability of dental implants

Objective: To evaluate the relationship between bone density measured by computed tomography (CT) and cone beam computed tomography (CBCT) (Sirona’s Galileos scanner) with primary stability of dental implants. Material and methods: 20 fresh bovine femoral heads were prepared by removal of soft tissue, sectioning of the bone, and placement of markers for location and angulation of implants. Bone density of peri-implant areas was determined preoperatively by CT and CBCT scanning of the prepared bone samples represented by Hounsfield units (HUs) and gray values (GVs), respectively. Then, 60 implants in three sizes (diameter = 4 mm, length = 8, 10, and 12 mm) were inserted into the bones and maximum insertion torque (IT) was recorded. Osstell device was also used for determining the implant stability quotient (ISQ) for each implant. Statistical analysis was performed on the data (alpha = 0.05). Results: Mean ± SD values of GV, HU, and ISQ were 1592.75 ± 231.82, 675.26 ± 115.38 and 61.90 ± 10.14, respectively. Moreover, the most frequent IT limit was 30-35 Ncm (41.4%). Significant relationships were observed between HU and IT, GV and IT, HU and ISQ, GV and ISQ, and IT and ISQ in all implant sizes. Moreover, GV and HU also significantly correlated to each other. Conclusion: Bone density values in CBCT and CT scans are positively associated to primary stability of dental implants. Therefore, GVs obtained from Galileos CBCT scanner can be used for preoperative selection of edentulous sites which allow for better implant stability or locations which require further procedures for enhancing the success rate of dental implants. KEYWORDSComputed tomography; Cone beam computed tomography; Dental implant.

Impact of Socket Preservation Technique Using Autogenous Dentin Graft and Hydroxyapatite Crystals on Primary Stability of Dental Implants in Same Individuals: A Pilot Study

A pilot study was conducted to analyze and compare the stability of dental implants using 2 different graft materials (autologous dentin graft and an alloplastic hydroxyapatite [HA] crystal) in the same patient. As far as we know, this study is first of its kind where socket preservation has been done using 2 different grafts in the same patient. Ten patients undergoing extraction of at least 2 teeth were selected. Atraumatic extractions were performed. Out of the 2 extraction sockets, 1 was grafted with autogenous tooth graft and other with HA crystals. Computed tomography scan was performed 3 months after grafting to evaluate bone mineral density. Primary implant stability was measured using resonance frequency analysis. It was observed that among both sites, autogenous tooth grafted sites showed better results.

Association between Bone Density Values, Primary Stability and Histomorphometric Analysis of Dental Implant Osteotomy Sites on the Upper Jaw.

Sufficient bone volume, as well as the bone quality characteristics are necessary prerequisites to ensure optimal mechanical stability of the implants and subsequent osseointegration. The aim of the present study was to assess the correlation between bone density values obtained by cone-beam computed tomography (CBCT), the primary stability of dental implants and the histomorphometric analysis of bone quality. Following tooth extraction, socket preservation with frieze-dried bone allograft or protein-rich fibrin (PRF) was performed on 30 patients with 30 maxillary teeth in the region from second premolar to second premolar. Four months after the procedure, CBCT was used to assess the bone density (Hounsfield units) in the area of extraction. Thirty bone samples were harvested from implant sites using a trephine drill. They were analyzed with Image J software. Immediately after placing the implant, the implant stability quotient was measured using the Osstell Idx device. The results revealed significant correlations between bone density and primary stability along the vestibulo-oral (r=0.392, p=0.032) and mesiodistal axes (r=0.407, p=0.026). Bone density also correlated strongly with the percentage of newly formed bone (r=0.776, p<0.001). Bone quality, in terms of bone density measured in CBCT and new bone formation are correlated to the primary stability of the dental implants and vice versa.

Can the Bone Density Estimated by CBCT Predict the Primary Stability of Dental Implants? A New Measurement Protocol.

The use of dental implants to restore edentulous parts of the jaws is a common and well-documented treatment method. Effective dental implant treatment is known to be affected by both the quality and the quantity of bone required for implant placement, bone quality is a critical factor to consider when predicting stability of implants. Thus, stability of the initial implant and the possibility of early loading could be predicated using cone-beam computed tomography (CBCT) scans and primary stability parameters before implant placement. The aim of this study was to objectively assess bone density obtained by CBCT and the correlations with primary stability of dental implants using implant stability meter IST device. A total of 40 implants were placed in 16 patients (9 males and 7 females with a range of 22 to 61 years (mean age 40.44 ± 12.3 years). The bone densities of implant recipient sites were preoperatively recorded using CBCT. The maximum insertion torque value of each implant was measured by engine during implant placement and compared to the primary stability for every implant using implant stability meter device (IST). A statistically significant correlation was found between bone density value from CBCT with the primary implant stability and insertion torque. Although the small samples size, the study shown bone density assessment using CBCT is an efficient method and significantly correlated with primary stability using implant stability meter device IST and insertion torque.

Effect of bone quality and quantity on the primary stability of dental implants in a simulated bicortical placement

ObjectivesConventional dental implants inserted in the molar region of the maxilla will reach into the sinus maxillaris when alveolar ridge height is limited. When surgery is performed without prior augmentation of the sinus floor, primary stability of the implant is important for successful osseointegration. This study aimed at identifying the impact of bone quality and quantity at the implantation site on primary implant stability of a simulated bicortical placement.Materials and methodsIn our in vitro measurements, bone mineral density, total bone thickness and overall cortical bone thickness were assessed by micro-computed tomography (μCT) of pig scapulae, which resembled well the bicortical situation found in human patients. Dental implants were inserted, and micromotion between bone and implant was measured while loading the implant with an axial torque.ResultsThe main findings were that primary implant stability did not depend on total bone thickness but tended to increase with either increasing bone mineral density or overall cortical bone thickness.Clinical relevanceLimited bone height in the maxilla is a major problem when planning dental implants. To overcome this problem, several approaches, e.g. external or internal sinus floor elevation, have been established. When planning the insertion of a dental implant an important aspect is the primary stability which can be expected. With other factors, the dimensions of the cortical bone might be relevant in this context. It would, therefore, be helpful to define the minimum thickness of cortical bone required to achieve sufficient primary stability, thus avoiding additional surgical intervention.

Effect of Surface Modification on the Primary Stability of Dental Implants by Plasma Oxidation and Storage Treatment

Plasma oxidation could produce an oxidized surface, resulting in a graded TiO2−x film layer and significantly improving dental implant hydrophilicity and biocompatibility. Unfortunately, these features are gradually lost by the influence of the environment. In this study, alkali storage was used to improve these characteristics at room temperature. Titanium samples were divided into sandblasting acid-etching (SLA), oxidation (SLA samples that were oxidized), and storage (SLA samples that were oxidized and stored in 0.1 mol/L NaOH solution) groups. We measured the surface properties of each group, including the roughness, chemical composition, and hydrophilicity of these materials. We investigated the effects of titanium storage on cell responses, including cell attachment, proliferation, differentiation. We also investigated the osseointegration of the stored titanium implants. The results showed that the storage process maintains the superhydrophilic properties of oxidation treatment. Oxidized samples promoted cell responses. The descending order of biocompatibility was storage &gt; oxidation &gt; SLA. Furthermore, oxidation and alkali storage had significant effects on bone growth at the early stage of the implant. These results suggested that alkali storage can suitably maintain the surface characteristics of plasma oxidation, and the combination of oxidation and storage treatment can improve the primary implant stability.

Primary Stability of Dental Implants in Low-Density (10 and 20 pcf) Polyurethane Foam Blocks: Conical vs Cylindrical Implants.

Background: The aim of the present study was to compare, in low-density polyurethane blocks, the primary implant stability values (micromobility) and removal torque values of three different implant geometries in two different bone densities representing the structure of the human posterior jaws. Methods: A total of 60 implants were used in the present investigation: twenty implants for each of three groups (group A, group B, and group C), in both polyurethane 10 pcf and 20 pcf densities. The insertion torque, pull-out torque, and implant stability quotient (ISQ) values were obtained. Results: No differences were found in the values of Group A and Group B implants. In both these groups, the insertion torques were quite low in the 10 pcf blocks. Better results were found in the 20 pcf blocks, which showed very good stability of the implants. The pull-out values were slightly lower than the insertion torque values. High ISQ values were found in Group A and B implants. Lower values were present in Group C implants. Conclusions: The present investigation evaluated implants with different geometries that are available on the market, and not experimental implants specifically created for the study. The authors aimed to simulate real clinical conditions (poor-density bone or immediate post-extraction implants) in which knowledge of dental implant features, which may be useful in increasing the primary stability, may help the oral surgeon during the surgery planning.

Influence of cortical bone and implant design in the primary stability of dental implants measured by two different devices of resonance frequency analysis: An in vitro study.

BackgroundThis study aimed to evaluate the effect of the implant design and the presence of cortical bone in the primary stability, as well as analyze the differences between the stability measurements obtained by two different resonance frequency analysis (RFA) devices. Material and MethodsA total of 80 Klockner implants of two different models [40 Essential Cone implants (group A) and 40 Vega implants (group B)] were used. The implants were placed in two polyurethane blocks that simulated the mechanical properties of the maxillary bone. One block featured a layer of cortical bone that was absent from the other block. The primary stability of all implants was measured by insertion torque and RFA using two different devices: Penguin RFA and Osstell IDX. ResultsPrimary stability was superior in the cortical bone in both torque and RFA. In the block containing cortical bone, group A implants obtained a greater insertion torque than did group B. The insertion torque was lesser in the bone lacking cortex. Regarding the ISQ of the implants, group A presented higher values in the block with cortical bone, but the values were lower in the block without cortical bone. There were no significant differences between the values obtained from the Osstell IDX and Penguin RFA. ConclusionsThe presence of cortical bone positively influences the primary stability of dental implants. The design of the implant also has a statistically significant influence on implant primary stability, although the impact depends on whether there is coronal cerclage or not. There were no statistically significant differences in the implant stability measurements obtained by two different devices. Key words:Implant stability, resonance frequency analysis, torque, osstell, penguin, cortical.

The effects of implant design, bone quality, and insertion process on primary stability of dental implants: an in-vitro study

The aim of this study was to analyse the maximum insertion torque (MIT) with respect to the implant thread face angle, bone quality and the insertion process. Two implants were designed and made: one with high face angle (HFA) and the other with low face angle (LFA). Bovine bones were classified, and then the MIT values of the implants were measured per round using standard protocol. Finally, three-way ANOVA was used to interpret the MIT values. For the main effects, MIT values (mean and standard error) of LFA (17.4 ± 0.7 N cm) and HFA implants (20.8 ± 0.7 N cm) were significantly different. The MIT values for the D4 (9.4 ± 0.6 N cm), D3 (19.1 ± 0.7 N cm), and D2 (28.8 ± 1.1 N cm) bones were significantly different. Considering the higher primary stability as an essential provision for immediate load implants, it is recommended to use implants featured with higher thread face angles.

Calculating ISQ Primary Stability of a Dental Implant through Micromotion

There are several types of primary and secondary stability measuring methods, but there are no calculating methods to determine direct primary stability. The aim of this work is to make a calculation method for primary stability. The out coming result of the calculation should be the same form and unit as available in the clinical and used RFA (Resonance Frequency Analysis) method, especially the ISQ (Implant Stability Quotient). Dental implant analog screws were inserted in bone modelling standard PUR (Polyurethane) solid foam blocks, and the insertion torque and the micromotion was monitored. The ISQ values of the inserted screws were measured also. On the basis of results, the characteristic equation was determined, which showed an excellent correlation (r = 0.96) between the micro mobility and ISQ. To simulate the micro mobility of an inserted screw with FEA (Finite Element Analysis) in any case of the change the bone material properties is not difficult instead of in vitro and in vivo examinations. Using the simulation results and the characteristic equation the clinically used ISQ value could be determinable. Thanks to this simple method, it is easy to monitor virtually the stability change in any lesion of bone structure. As a result of the conducted measurements and simulations, it can be concluded that the ISQ value, which represent the implant primary stability, can be calculated via FEA. With this simulation method, it is possible to predict and monitor pre-clinically the primary stability of dental implants with new geometries.