| Abstract|| |
Introduction: Osseointegration as formulated by Alberktson is crucial for implant survival and success. Osseointegration is a measure of implant stability. Measuring implant stability helps to arrive at decisions as to loading of an implant, allows protocol choice on a patient to patient basis and provides enhanced case documentation. The RFA technique provides with clinically relevant information about the state of the implant–bone interface at any stage after implant placement. Aim: Evaluation of primary and secondary stability between implants of two different systems by resonance frequency analysis device. Methodology: This study was conducted among 17 patients divided into two groups. Group 1 (n = 10) receiving 20 MIS seven implants and Group 2 (n = 7) received 20 Alphadent active implants. The primary implant stability was measured at the time of implant placement and secondary stability is measured at 3–4 months interval using RFA device OSSTELL ISQ. Statistical analysis was performed using paired t test for intra group and independent sample test for intergroup comparisons. Results: No statistically significant differences in primary and secondary stabilities were found between the implant systems at either time intervals (P > 0.05). A positive correlation was noticed between mesiodistal stability and implant diameter in MIS seven group (P < 0.05). A positive correlation was noticed between mesiodistal, labiolingual stabilities and implant diameter in Alphadent group (P = 0.03). A positive correlation was noticed between mesiodistal, labiolingual stabilities and implant length in Alphadent group (P = 0.03). Conclusion: From the present data, it can be concluded that within the limitations of study, implant systems used and their design features showed no significant correlation to implant stability between the groups. More studies are required to assess the effect of implant designs and surface conditions on implant stability on a long-term basis.
Keywords: Endosseous implants, osseointegration, primary stability, resonance frequency analysis, secondary stability
|How to cite this article:|
Kastala VH, Ramoji Rao MV. Comparative evaluation of implant stability in two different implant systems at baseline and 3–4 months intervals using RFA device (OSSTELL ISQ). Indian J Dent Res 2019;30:678-86
|How to cite this URL:|
Kastala VH, Ramoji Rao MV. Comparative evaluation of implant stability in two different implant systems at baseline and 3–4 months intervals using RFA device (OSSTELL ISQ). Indian J Dent Res [serial online] 2019 [cited 2020 Aug 5];30:678-86. Available from: http://www.ijdr.in/text.asp?2019/30/5/678/273426
| Introduction|| |
Replacement of missing teeth with dental implants represents one of the most successful treatment options in dentistry today. Osseointegration, as formulated by Alberktson, is crucial for implant survival and success. Osseointegration is a direct functional and structural contact between living bone and the surface of load bearing implant. Osseointegration is a measure of implant stability. Implant stability is determined by the mechanical properties of bone tissue at implant site, bone maturation, bone remodelling, bone density and degree of engagement of implant within bone. This is gained in two different stages. Primary stability results from mechanical engagement of implant within cortical bone. This depends on bone density, surgical technique and implant geometry. Secondary stability results from regeneration and remodeling of bone and tissue around the implant that is determined by primary stability, bone maturation, remodeling and bone density with time. Primary stability dictates and is positively associated with secondary stability.
A stable implant displays mobility on microscale where as a failed implant shows mobility on macroscale due to fibrous tissue that could be due to failed osseointegration after initial healing or gradual disintegration. Therefore, it implies that an initially successful but failing implant shows an increase in degree of micromobility. Implant stability, being the key element, needs to be evaluated at different time points to ensure successful osseointegration., Measuring implant stability helps to arrive at decisions as to loading of an implant, allows protocol choice on a patient-to-patient basis and provides better case documentation. Various methods are developed to assess implant stability such as histologic analysis, radiographs, percussion test, reverse torque test, cutting torque resistance analysis, periotest, and RFA (resonance frequency analysis) device.,,
Histologic analysis was considered gold standard to measure osseointegration but is not widely used though it is clinically accepted due to unnecessary biopsies required for implant stability assessment. Radiographic analysis is a non-invasive method that can be performed at any stage of healing and changes in radiographic bone level cannot precisely indicate implant stability. Percussion tests provide a ringing sound as a sign of good osseointegration and are not reliable as they provide poor qualitative information., Cutting torque resistance analysis utilizes energy that correlates to bone density further determining implant stability. It cannot assess the secondary stability and is not frequently used as a diagnostic aid as the lower limit value that denotes potential failure of implant has not been established., Reverse torque test proposed by Roberts et al. gives information on degree of bone to implant contact of any given implant and is not widely used as it can provide information as to all or none outcome (osseointegrated or failed) and it cannot quantify degree of osseointegration.,
Modal analysis measures the natural frequency or displacement signal of a system in resonance. It is performed in two models: theoretical and experimental. The experimental or dynamic modal analysis has been used to quantify degree of osseointegration and implant stability. Dental mobility checker developed by Aoki and Hirakawa utilizes the same principle as impact hammer method, provides measurements for osseointegrated implants. It has certain disadvantages such as difficulty in double tapping and the application of small force to an implant immediately after placement may jeopardize the process of osseointegration., Kaneko et al. used pulsed oscillation waveform to analyze the mechanical vibrational characteristics of the bone implant bone interface using forced excitation of a steady state wave but the sensitivity was low for assessment of implant rigidity. Dental Periotest has been thoroughly studied and advocated as a reliable method to determine implant stability. Readings of -8 to + 50 are interpreted. Succesfully integrated implants have yielded a wide range of periotest values. These variations suggest that for implants, there is no absolute value that is considered acceptable. Periotest cannot diagnose a borderline case or an implant in the process of osseointegration.,
Limitation of these methods, therefore, leads to the development of other diagnostic tests that are non-invasive, clinically applicable, user-friendly and reliable to measure implant stability such as the Resonance Frequency Analysis Device. In 1996, Meredith and coworkers first described the resonance frequency analysis for implant stability measurement which is commercially available as Osstell, Implomates, and Penguin. This technique measures the resonance of a transducer that is attached to implants to correlate with micromobility or displacement which, in turn, is determined by the bone density. The RFA technique provides with clinically relevant information about the state of the implant –bone interface at any stage after implant placement. It can be used an additional parameter to support decision-making during implant treatment and follow up.
RFA consists of a transducer connected to an implant, which is excited over a range of frequencies. RFA causes the implant to vibrate while at the same time, analyses the implant motion to provide information as an implant stability quotient (ISQ) on a scale from 1–100. During the measurement, smart peg was attached to the implant and the sleeve of the hand piece was kept at a distance of 0.5mm from the implant. The hand piece was held horizontally at right angles to the long axis of the implant and patient in an upright position. The scale ranged from 0–100. The higher values reflected greater stability.
Aim and objectives
Evaluation of primary (baseline) and secondary stability (3–4 month interval) of MIS Seven and Alphadent implant systems was conducted using RFA device Osstell ISQ.
This clinical trial was conducted among 58 patients visiting the Department of Periodontics, Drs Sudha and Nageswar Rao Siddhartha Institute of Dental Sciences, Chinnaoutapalli, Krishna District, Andhra Pradesh. The study protocol was approved by the institutional ethical committee. The purpose of the study was explained to all subjects and written informed consent was taken prior to the study. Patients with partially edentulous maxillary or mandibular arches were selected for the study following recording of clinical history and thorough oral examination. After thorough examination, patients meeting the inclusion criteria were divided into two groups, group-A comprising 10 patients planned to receive 20 MIS Seven internal hex implants and group-B,7 patients enrolled to receive 20 Alphadent active implants.
Patients enrolled into the study were selected based on inclusion and exclusion criteria.
Inclusion criteria: 1. Patients aged 18–60 years with single or multiple missing teeth. (Though the lower age limit for inclusion into study is 18 years, most of the patients included in the study were aged between 45–60 years), 2. systemically healthy patients, 3. adequate bone height (greater than 10mm) and bone width (greater than 4mm) at the sites planned for implant placement, 4. patients with bone density more than 750 HU (Hounsfield Units) 5. patients maintaining good oral hygiene, 6. patients smoking less than 20 cigarettes per day.
Exclusion criteria: 1. Patients with cardiac pacemakers, 2. patients with bleeding disorders, 3. patients with parafunctional habits such as bruxism, 4. patients who have undergone radiotherapy of head and neck in the last six months, 5. patients with history of acute coronary heart attack in the past one year.
Implant systems used in study
Design characteristics of MIS Seven implant system: It has self-tapping, surface thread design, internal hex with tricone connection and sandblasted surface which is acid-etched. This system offers implants of various lengths (6, 8, 10, 11.5, 13, 16 mm) and various diameters (3.3,3.75,4.20,5.0,6.0 mm). Implants are dispensed in double sterile packaging including implant fixture, final drill, cover screw. MIS implant system also supplies gingival former and corresponding abutments.
The second implant system used in this study was Alphadent implant system. It has symmetrical conical, spiral shaped, triple thread design. The surface is active, hydrophilic, a distinct layered microporous structure with an oxide layer of 10-12 μm. Titanium oxide film is enriched with calcium hydroxyapatite that stimulates active bone growth throughout the implant surface. It has microrings at the conical part for contact with cortical plate and intermediate threads that curve apically.
| Methodology|| |
This study was conducted in the following steps: 1. Diagnosis and treatment planning for implant, 2. Surgical protocol for group-A, 3. Surgical protocol for group–B, 4. Preoperative, intraoperative, postoperative evaluation by clinical and radiographic methods, 5. Collection of data and statistical analysis of results.
Diagnosis and treatment planning
Treatment planning was based on the following pre-treatment records and investigations
1. Detailed medical and dental history, 2. Diagnostic casts, 3. IOPA, OPG radiographs, 4. CBCT scan done to evaluate the quality and quantity of bone present at implant site as it is essential to evaluate the bone in order to establish implant insertion planning, 5. Investigations such as complete hemogram, INR, Hb%, ESR, PCV, bleeding time, clotting time, blood sugar levels and routine urine examination were done to evaluate the fitness of the patient for implant surgery.
Based on inclusion and exclusion criteria, patients were divided into two groups: Group A – MIS Seven implant placement, Group B – Alphadent implant placement Surgical protocols for Group A – MIS Seven implant placement.
All the surgical procedures were carried under strict aseptic conditions. The surgical site was scrubbed and the patient was aseptically draped. Surgery was performed under local anesthesia (lignocaine 20 mg/ml with adrenaline 1:80.000). After achieving adequate local anesthesia, crestal incision was placed on the site indicated for implant placement with No. 15 B. P. blade. Full thickness mucoperiosteal flap was elevated using periosteal elevator. Osteotomy was carried out following manufacturer's recommendations. Sequential drilling with copious irrigation was carried out till the desired osteotomy was prepared. Implant was placed in the prepared osteotomy and positioned with torque ratchet. The implant shoulder was kept at the level of the alveolar crest bone. Torque of 30-40 Ncm is achieved after implant placement into osteotomy site. IOPA X rays were taken using RVG device in a long cone technique during the surgery and immediately after the implant placement. Implant stability was evaluated with resonance frequency analyzer (RFA). To measure the implant stability smart peg was attached to the implant head. The transducer was kept along the occlusal surfaces of the teeth just 0.5 to 1 mm short of the smart peg. Repeated measurements were taken in mesiodistal, labiolingual directions and the value most frequently observed was recorded. The flap was closed with 3-0 black braided silk sutures to achieve primary closure.
Patients were postoperatively advised antibiotics and analgesics for a period of 5 days, oral rinse with chlorhexidinegluconate (0.2%) for a period of 15 days. After one week, sutures were removed. All the patients were reviewed at regular intervals.
After 3–4 months, with second stage surgery, implants were exposed and subsequently gingival former was placed for 15 days. Gingival former was removed and abutment placed. Another IOPA X ray was taken 3–4 months after the implant placement. The surgical protocol followed for placement of dental implants in group-B was similar to the procedure already described for MIS SEVEN implant placement.
Clinical and radiographic evaluation
Post operatively, all the implants in both the groups were evaluated with the following clinical parameters at baseline, 3–4 months.
1. Implant stability, 2. IOPA radiographs
Assessment of implant stability using Resonance Frequency Analyzer (RFA)
The implant stability was measured with the help of resonance frequency analyzer at baseline, 3–4 months. The RFA (OSSTELL Stampgatan, Sweden) was used for measurement of implant stability.
Descriptive and analytical statistics were done. The Shapiro Wilk test was used to check normaility of data. For evaluation of mean differences between the groups, independant sample and paired t-test were used wherever appropriate. Pearson correlation test was used to check association between variables.
Software: SPSS (Statistical Package for Social Sciences) Version 20.1 (Chicago, USA Inc., USA).
| Results|| |
Evaluation of the following clinical parameters: implant stability (mesiodistal and labiolingual) using RFA device OSSTELL ISQ was carried out at two time points, 1. at the time of implant placement and 2. at 3–4 months interval during placement of abutment. The mean age of the study population among MIS seven group was 55.15 with a standard deviation of 15.06. Among the alphadent group, the mean age of the population was 45.10 with a standard deviation of 11.53.
Intragroup comparison of mesiodistal implant stability in the MIS seven group reveals a mean ISQ value of 73.45 ± 8.19 at baseline and 74.42 ± 19.21 at 3–4 months. The mean difference in ISQ between two time points is 0.97 is not statistically significant [Table 1] and [Graph 1].
|Table 1: Intragroup comparison of mesio.distal and labio.lingual implant stability at baseline and at 3.4 months|
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Mean mesiodistal implant stability values within Alphadent group at baseline was 77.42 ± 5.66 and at 3–4 months interval was 75.25 ± 7.11. The mean difference in implant stability was 2.17 reveals statistical insignificance [Table 2] and [Graph 2]. The labiolingual implant stability comparison within MIS seven implant system group at two-time points baseline and after three months revealed a mean baseline ISQ value of 73.85 ± 7.55 and 73.95 ± 19.10, respectively. The mean difference in ISQ value of 0.10 reveals statistical insignificance [Table 1] and Gragh 3]. The labiolingual implant stability values at both time points baseline and after a 3–4 month interval within alphadent active group were 76.42 ± 6.12 and 76.20 ± 6.81, respectively. The mean difference in mean stability value is 0.22 which is not statistically significant [Table 1] and [Graph 3].
|Table 2: Mean age of the study population among the two groups-MIS Seven and Alphadent active implant system. |
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Intergroup comparison of mesiodistal implant stability at baseline was done by utilizing independent sample t test. P value <0.05 was considered to be statistically significant. The mean mesiodistal implant stability at baseline for the MIS seven is 73.45 ± 8.19 and among Alphadent active group, the value is 77 ± 5.66. The mean difference in stability is 3.97ISQ. Thus, it is evident that the average mesiodistal ISQ value did not differ significantly at baseline between the groups [Table 3] and Graph 1]. Intergroup comparison of mean mesiodistal implant stability at 3–4 months for the MIS seven group showed ISQ of 74.42 ± 19.21 and alphadent group showed 75.25 ± 7.11. The mean difference is 0.82 which is not statistically significant [Table 3] and [Graph 1]. Intergroup comparison of mean labiolingual implant stability at baseline for the MIS seven group was 73.85 ± 7.55 and Alphadent group showed a mean labiolingual stability at baseline was 76.42 ± 6.12. The mean difference in stability is 2.57. Thus, it is evident that the average labiolingual ISQ value didnot differ significantly between groups [Table 3] and [Graph 3]. The intergroup comparison of mean labiolingual implant stability values after 3-4 are 73.95 ± 19.10 in MIS seven group and 76.20 ± 6.81 in alphadent active implant group. Though both groups showed a mean difference of 2.25ISQ, this difference is not statistically significant [Table 3] and [Graph 3].
|Table 3: Intergroup comparison of mesio-distal and labio-lingual implant stability at baseline and at 3-4 months|
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Mesiodistal and labiolingual implant stability values after a 3-4 month interval in MIS implant group are correlated to implant diameter with r-value of 0.625 and 0.606 respectively. P = 0.03 derived from Pearson correlation test indicates statistically significant correlation between mesiodistal implant stability and implant diameter at baseline. P = 0.005 for labiolingual implant stability at 3-4 month interval indicates statistical significance. Correlation between implant length and mesiodistal, labiolingual stabilities at baseline and 3-4 month interval among MIS group were not observed [Table 4].
|Table 4: Correlation between diameter, length of implant to mesio-distal and labio-lingual stability at baseline and at 3-4 months of MIS Seven and Alphadent active implant system|
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Correlation was observed between implant diameter and mesiodistal, labiolingual stabilities at baseline and 3-4 month interval in the alphadent group revealing a r-valvue of -0.384, -0.268, respectively and P = 0.031 suggests statistical significance. Correlation between implant length and labiolingual stabilities at baseline in the alphadent group was observed revealing a r-value of-0.486 and P = 0.030 is statistically significant [Table 4]. Comparison of mesiodistal implant stability at baseline and 3–4 months for the two groups – MIS Seven and Alphadent Active implant system reveals that primary stability of Alphadent group is greater than MIS group, a decrease in secondary stability at 3–4 months among Alphadent group and a rise in secondary stability at 3–4 months among MIS group [Graph 4].
Comparison of labio-lingual implant stability at baseline and 3–4 months for MIS Seven and Alphadent Active implant system suggests an insignificant change in labio-lingual implant stability at baseline and 3–4 months of the two groups – MIS Seven and Alphadent Active implant system [Graph 5].
Correlation between diameter of implant and mesiodistal implant stability at 3–4 months of MIS Seven implant system was noticed revealing an increase in stability with increase in diameter. 4.2, 5.0 mm diameter implants showed better mesiodistal stability than 3.2 mm diameter implants [Graph 6]. Correlation between diameter of implant and labio-lingual stability at 3–4 months of MIS Seven implant system was noticed revealing an increase in stability with increase in diameter. 4.2, 5.0 mm diameter implants showed better labiolingual stability than 3.2 mm diameter implants [Graph 7]. Correlation between diameter of implant and mesio-distal stability at 3–4 months of Alphadent Active implant system was noticed revealing an increase in stability with increase in diameter. 3.75, 5.0 mm diameter implants showed better stability than 3.2 mm diameter implants [Graph 8]. Correlation between length of implant and labio-lingual stability at baseline of Alphadent Active implant system was noticed revealing highest stability for implant lengths of 11.5 mm and 16mm implants [Graph 9].
| Discussion|| |
The advent of novel implant designs over the last decade makes it prudent to critically evaluate parameters that determine their long-term survival. Implant stability is one such parameter that measures the anchorage, quality of implant in alveolar bone at various time intervals at the time of placement (Primary stability) and after 3–4 months of bone healing (secondary stability). The accurate method of measuring Implant stability is studied over time by various methods such as resonance frequency analysis, periotest, and finite element analysis. RFA is proven to be an accurate method to access implant stability., In the present study, Osstell ISQ, that utilizes RFA technology was used to determine implant stability. Implant stability portrays the process of osseointegration, pattern of implant loading and implant success.
Sennerby and Roos, hypothesized that an ISQ value of >60 is indicative of success, and an ISQ value <45 indicates implant failure. However, such thresholds still lack sufficient evidence in terms of the exact time of the greatest change in post insertion stability. The increase or decrease in implant stability can be attributed to the changes occurring at the bone-implant interface during the early healing phase.
Literature with regard to implant stability measured by the Osstell device in different directions is very scarce.,, Sim and Lang 2010, Park et al. 2011 recommend the use of bidirectional measurements that are approximately perpendicular to each other in order to secure the highest and lowest ISQ values., Seong et al. (2008) stated that wide variability in the results are obtained from bi directional application of the Osstell probe. Two-directional assessments may reveal more sensitive information than uni-directional readings. Measurement of the stiffness of the bone/implant complex in one direction reflects the stability of an implant only partially, because implant–bone fusion occurs at 360° around a fixture and implant stability is a general reflection of this fusion.
Primary stability at the time of placement is determined by many factors such as implant design, drilling protocol, bone morphology and implant dimensions. Our study evaluated the impact of two different implant designs, i. e., MIS Seven and Alphadent active on primary stability. In the MIS implant group we obtained a baseline ISQ value of 73.45 (MD) 73.85 (LL). Though these ISQ values indicate good primary stability we did not observe a significant difference between the bidirectional measurements. These values could be attributed to the unique design features such as cervical microthreads which improve BIC and minimise compressive stress. In addition, since MIS Seven implants are self-tapping, the bone drilling technique might have contributed to the primary stability as indicated by Marković et al. in 2013. This design also promotes denser bone in the pitch region due to compressive threads and minute lateral displacement on bone tissue during implant insertion.
In terms of secondary stability, the MIS group implants showed an insignificant augment in ISQ of 74.42 (MD) and 73.95 (LL) after three months. Secondary stability at 3–4 months is influenced by multiple factors which like implant surface topography, bone quality and patient related factors. MIS implants possess acid etched and sand blasted surface morphology that optimises tissue response promoting osteoconductivity and early bone deposition. Gottlow et al. 2013 stated that sand blasted implants exhibit better secondary stability than oxidized implant surfaces. In addition, rough implant surfaces present a larger surface area and allow a finer mechanical attachment to surrounding tissues. Guizzardi et al. 2004, Franchi 2007, and Guilherme Jose 2016 have demonstrated that sand blasted implant surfaces accelerate peri-implant osteogenesis by enhancing adhesion, growth and metabolic activity of osteoblasts.,,
Among the alphadent group, the primary stability (77.42 ISQ) was noted to be insignificantly greater than in MIS group (73.45 ISQ). This high primary stability could be attributed to implant features such as conical implant body and symmetrical, spiral-shaped thread design. Implant body has a conical shape that matches the shape of the drill, thereby ensuring good primary fixation into osteotomy site. Antirotational sulcus and curving in the apical part also enhance the adherence of implant to osteotomy walls. Enhanced contact with surrounding cortical plate is a prerequisite to achieve primary stability which could be due to microrings at the cervical part of alphadent implants and intermmediate threads on the implant surface which enhance bone–implant contact (BIC). Anodized surface throughout the implant enhances active bone growth that quickly promotes mechanical (primary) stability. Duncan et al. 2011 stated that anodic oxidation increases early integration in Osstem implants due to formation of a porous titanium oxide film on surface of titanium implants increasing surface roughness and concentration of calcium and phosphate ions. Marković et al.(2013), stated that bone-drilling technique significantly increases primary implant stability in low-density bone regardless of the macro-design of the implant used. This increased stability could be due to undersized drilling technique used in our study to achieve a firm implant placement into osteotomy site that brings about changes in the micromorphology of peri-implant trabecular bone caused by apico-lateral condensation.
Secondary implant stabilities labiolingual (76.2 ISQ), mesiodistal (75.25 ISQ) were high among Alphadent group and were maintained without significant drop in stability. Threads at various levels of height on implant surface that allows greater implant stability even in soft bone and prevents further bone resorption. Surface is active and hydrophilic due to anodic oxide layer of thickness 10–12 microns. This multilayer surface enhances concentration of calcium and phosphate ions that allows bony tissue to grow deeper and in between micropores. Sul et al. 2005, Guilherme Jose 2016 also supported that high secondary implant stability and successful osseointegration are attributed to titanium oxide film that enhances cell viability, cellular and tissue response that benefits osseointegration.,
The mean mesiodistal, labiolingual ISQ values did not differ significantly neither at baseline nor at 3-4 month interval between the groups. Esposito et al. found no evidence that any particular type of dental implant has superior long-term success. Pimentel Lopes de Oliveira et al. 2016 compared primary, secondary stabilities of implants with anodized surfaces and implants treated by acids and proposed that there is no significant difference.
The length and diameter of the implants placed in this study were determined according to the available bone height and ridge width. Implants of at least 3.25 mm in diameter and 10 mm in length were used but the large majority of implants were regular-sized (mean implant length: 11.5 mm; mean implant diameter: 4.2 mm). There is a statistical significant correlation between labioloingual stability and implant diameter among MIS implant system (P = 0.005). Emphasized relationship between implant diameter and ISQ values.,, Wider implants are more appropriately engaged with buccal and lingual cortical plates and offer a larger surface for osseointegration, thereby exhibiting more primary and secondary stability.,,
With regard to secondary stability, one should expect that given the same architecture, wider-diameter implants result to be more stable than thinner ones because they can potentially engage a larger amount of osseointegrated interface. This study revealed a statistical significant correlation between mesiodistal stability and implant diameter among MIS implant system (P = 0.003). Veltri et al. proved that a strong positive correlation exists between ISQ values expressing secondary stability and the simulated bone–implant contact due to increase in implant diameter.
There is a statistical significant correlation between mesiodistal, labiolingual stability and implant diameter among Alpha dent implant system (P = 0.031). Rokn et al., Quesada-García et al. evaluated that implant diameter had a positive influence on ISQ values in both implant systems, which might also be attributed to greater implant-bone contact area as the diameter increases., In this study 11.5,13 mm implants show better stability than 10mm implants of the same diameter. There is a statistical significant correlation between mesiodistal, labiolingual stability and implant length among Alpha dent implant system (P = 0.031). Barikani et al. propsed that among long implants irrespective of diameter of the replace select system showed higher stability compared to Branemark implants.
Lekholm et al. 1994 stated that most of the failed implants were were 7mm or 10 mm in length. Long implants are necessary for successful osseointegration to ensure greater surface area for bone contact.
The RFA technique has been extensively used in clinical research for the last two decades. Nonetheless, from available literature, there is still a lack of precise information on the correlation between ISQ values and the short-and long-term implant outcomes as the implants in both systems were followed up only for a period of 3–4 months. All these findings support further that single RFA measurements of an implant do not allow assessment of its current status or prediction of its performance. Only repeated measurements over a longer period of time would have clinical significance and prognostic value. Still however, future prospective as well as retrospective studies, are certainly needed to establish threshold ranges for implant stability and for implants at risk for losing stability.
| Conclusion|| |
Within the limitations of the present study, it can be concluded that discrepancy in implant stability was statistically not significant between MIS seven implant and Alphadent active implant groups neither at the time of implant placement nor at 3-4 month interval. Mesiodistal and labiolingual Implant stabilities were high at the time of implant placement and increased insignificantly with time in MIS seven group. Mesiodistal and labiolingual implant stability were high initially and well maintained, but ISQ values decreased insignificantly at 3-4 month interval time in Alphadent active group. Among both implant systems, there was a statistically significant correlation of implant stability to implant diameter and among Alphadent group, to implant length. Drawbacks of the study include lack of standardization of site of implant placement and lack of correlation between bone density, torque values to implant stability. Since the sample size and study evaluation period was small, a long-term study with larger sample size is recommended to further authenticate the results of the study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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Dr. Vidya Hiranmayi Kastala
Department of Periodontics and Implantology, Drs. Sudha and Nageswar Rao Siddhartha Institute of Dental Sciences, Chinnaoutapalli, Gannavaram Mandal, Krishna District - 521 286, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2], [Table 3], [Table 4]