Reliability and validity of the instrumental assessment of implant stability in dry human mandibles

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL RELEVANCE

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

Comparison of Primary Stability of Implants Installed by Two Different Methods in D3 and D4 Bone Types: An In Vitro Study

Objective:

The purpose of the study is to assess the method of implant insertion in D3 and D4 bones and influence of insertion torque for achieving better primary implant stability.

Materials and Methods:

A total of 32 specimens (wood blocks) simulating D4 and D3 bone were grouped into 1, 2, 3, and 4. In groups 1 and 3, the implant and abutment were placed by manual method while in groups 2 and 4 by motor-driven method. The osteotomy site was prepared as per the protocol for soft bone, and implants were placed till the implant platform was in flush with the surface of the block. After achieving a standard insertion torque of 40 N.cm, pullout test was carried out with a universal testing machine and results were analyzed by one-way analysis of variance.

Results:

An intergroup comparison of peak loads revealed an overall statistically significant difference (P < 0.0001) with a mean of 442.638 N, maximum in group 4 and least (202.963 N) in group 1. The mean elongation break was found to be maximum in group 3 samples (81.67600%) and less in group 4 (37.15113%). Intergroup comparison of Young’s modulus was statistically significant (P < 0.0001) with a mean value found to be minimum among group 1 samples (597.54750 MPa) and maximum in group 2 (1056.76463 MPa). An intergroup comparison of yield points was found to be maximum among group 4 samples (16.17238MPa) and least in group 1 (5.77438MPa).

Conclusion:

The D3 bone sample provided greater primary stability of implant than D4 bone samples, and the motor-driven implant seemed to have improved stability than that placed manually.

PRIMARY STABILITY IN VARIOUS-LEVELS IMPACTED IMPLANTS: AN EX-VIVO STUDY

The aim of this study was to examine the primary stabilization of different vertically impacted bone implants. Implant stability was measured by resonance frequency analysis. Forty-five dental implants were used and divided into three groups. Group 1 was placed 4 mm (1/3 impacted), Group 2 was placed 8 mm (2/3 impacted), and Group 3 was placed 12 mm (fully impacted). Implant stability quotient values were measured on the longitudinal and transversal axis by two independent researchers. The fully-impacted group showed the significantly highest value among the groups (p < 0.05). There were statistically varying implant-stability quotient values between researchers. None of the 1/3 impacted implants' value reached a 70 implant-stability quotient value.

Initial Stability Measurements of Implants Using a New Magnetic Resonance Frequency Analyzer With Titanium Transducers: An Ex Vivo Study

The establishment of dental implant stability is mandatory for successful osseointegration. Resonance frequency analysis (RFA) is the most frequently used method for the clinical measurement of implant stability. The purpose of the present study was to evaluate the reliability of the recently developed RF analyzer Penguin RFA and to compare it with the traditional RF analyzer Osstell ISQ. Sixty implants were inserted into fresh steer vertebrae and pelvis. Implant stability was measured using Penguin RFA by its transducers (multipegs) and Osstell ISQ by its transducers (smartpegs). Additionally, stability was measured by multipegs with Osstell ISQ and by smartpegs with Penguin RFA. The intraobserver and interobserver reliability of Penguin RFA were estimated by the intraclass coefficient (ICC). Mean implant stability quotients (ISQs) measured with Osstell ISQ were higher than the ISQs measured with Penguin RFA (P < .05). The intra- and interobserver reliability of Penguin RFA were considered as excellent (ICC > 0.7). For Osstell ISQ, no significance in ISQs was detected between the readings by smartpegs and multipegs (P > .05), while for Penguin RFA ISQs by smartpegs were significantly higher than the ISQs by multipegs (P <.05). The recently developed Penguin RFA is reliable and can be used in clinical practice for the measurement of dental implant stability regardless of the bone type. The multipegs originally manufactured for the Penguin RFA is also compatible with Osstell ISQ.

Is clinical experience important for obtaining the primary stability of dental implants with aggressive threads? An ex vivo study

Background

The aim of this study was to investigate the clinicians’ experience on maintaining the primary stability of implants with aggressive threads belonging to a novel dental implant system.

Material and Methods

Three hundred implants with aggressive threads were inserted in fresh bovine ribs mimicking Type IV bone by five clinicians which were classified according to their previous experience of total number of implant insertion. An independent examiner measured the primary stability of all implants after insertion by using resonance frequency analysis (RFA), electronic percussive testing (EPT) and removal torque methods.

Results

No significant differences were detected between the stability values measured by the clinicians (p< 0.05) except the Periotest values (PTVs) of the non-experienced clinician. PTVs of the non-experienced clinician were significantly higher than the PTVs of the expert and good clinicians (p >0.05). Significantly higher stability values were detected in the secondary insertion of the non-experienced clinician as compared to her initial insertion values (p >0.05). No significant differences were detected between the first and second measurements of the other clinicians (p< 0.05).

Conclusions

Within the limitations of this ex-vivo study, it may be concluded that experience does not play an important role in maintaining the stability of implants with aggressive threads.

Key words:Implantology, experimental design, osseointegration.

Influence of torsional strength on different types of dental implant platforms

AIM

The study assessed deformation of implant components submitted to torsion tests of 80 and 120 N · cm using an optical stereomicroscope.

MATERIAL AND METHODS

The following 3 types of Titaniumfix conical implant connections (n = 5) measuring Ø 4.0 × 11.5 mm were used: external, internal hexagon and Morse taper connections. The diagonal and lateral measurements of the hexagon implant platform were measured before and after the torsion test.

RESULTS

The torsion test using torque of 80 and 120 N · cm altered the implant dental platforms. All groups presented deformation of implant component after torque of 80 N · cm with no statistical difference among them. During torque of 120 N · cm, a difference in the Morse taper connection in relation to the internal and external hexagon connection was observed. The Morse taper connection implant, followed by the internal hex implant, underwent less deformation. Greater deformation occurred in the external hex implants.

CONCLUSION

For all the implants, high insertion torques deformed the implant platform preventing long-term maintenance and stability of implants.

Stability, Survival, and Tolerability of an Auditory Osseointegrated Implant for Bone Conduction Hearing: Long-Term Follow-Up of a Randomized Controlled Trial

OBJECTIVE

To compare implant stability, survival, and soft tissue reactions for a novel (test) and previous generation (control) percutaneous auditory osseointegrated implant for bone conduction hearing at long-term follow-up of 5 years.

STUDY DESIGN

Single follow-up visit of a previously completed multicenter, randomized, controlled trial.

PATIENTS

Fifty-seven of the 77 participants of a completed randomized controlled trial on a new auditory osseointegrated implant underwent a single follow-up visit 5 years after implantation, which comprised implant stability measurements and collection of Holgers scores. Additionally, implant survival was recorded for all 77 patients from the original trial.

RESULTS

The test implant showed significantly higher implant stability quotient (ISQ) values compared with the control implant throughout the 5-year follow-up. Mean area under the curve of ISQ high from baseline to 5 years was 71.6 (standard deviation [SD] ±2.0) and 66.7 (SD ±3.4) for the test and control implant, respectively (p < 0.0001). For both implants, the mean ISQ value recorded at 5 years was higher compared with implantation (test group +2.03 [SD ±2.55, within group p < 0.0001] and control group +2.25 [SD ±4.95, within group p = 0.12]). No difference was noticed in increase from baseline between groups (p = 0.64). Furthermore, evaluation of soft tissue reactions continued to show superiority of the test implant. At the 5-year follow-up visit, one patient (2.5%) presented with a Holgers grade 2 in the test group, compared with four patients (23.5%) in the control group (p = 0.048); no patient presented with more severe soft tissue reactions. Excluding explantations, the survival rate was 95.8% for the test group and 95.0% for the control group. The corresponding rates including explantations were 93.9 and 90.0%.

CONCLUSION

The test implant showed superiority in terms of higher mean ISQ values and less adverse soft tissue reactions, both at the single 5-year follow-up visit and during the complete follow-up. In addition, both implants showed an equally high implant survival.

Application and Interpretation of Resonance Frequency Analysis in Auditory Osseointegrated Implants: A Review of Literature and Establishment of Practical Recommendations

OBJECTIVE

To establish standardization of implant stability measurements in auditory osseointegrated implants by means of resonance frequency analysis (RFA) through reviewing the currently published literature.

METHODS

Studies reporting on RFA in auditory osseointegrated implants were identified, and the outcomes and the way these were reported were evaluated.

RESULTS

Thirteen clinical studies reporting RFA outcomes of auditory osseointegrated implants were identified and analyzed, which demonstrated variations in methodology and reporting of data. The different reporting standards made a meta-analysis impossible. Heterogeneity and limitations were found in reporting of the types of implants, abutments, and SmartPegs used; study population sizes; follow-up duration; and, reporting of the implant stability quotient (ISQ).

CONCLUSION

RFA is an interesting outcome of clinical studies on auditory osseointegrated implant research and might have potential as a clinically relevant tool for assessing implant stability. Because of the heterogeneous data that have been reported to date, the following guidelines for standardization of application and reporting were established. The implant and abutment type and length, and the type of SmartPeg should always be stated. Absolute stand-alone ISQ values should not be interpreted individually. ISQ values are at this moment most meaningful as a trend in the individual patient or in a population over time. No conclusions should be based on individual ISQ values. Standardized time points for RFA in research should be determined prospectively, with surgery as a baseline. After abutment replacement, individual ISQ trends from baseline cannot be interpreted anymore if the abutments differ in length.

Comparative ex vivo evaluation of two electronic percussive testing devices measuring the stability of dental implants

BACKGROUND

A comparative ex vivo study was performed to determine electronic percussive test values (PTVs) measured by cabled and wireless electronic percussive testing (EPT) devices and to evaluate the intra- and interobserver reliability of the wireless EPT device.

METHODS

Forty implants were inserted into the vertebrae and forty into the pelvis of a steer, a safe distance apart. The implants were all 4.3 mm wide and 13 mm long, from the same manufacturer. PTV of each implant was measured by four different examiners, using both EPT devices, and compared. Additionally, the intra- and interobserver reliability of the wireless EPT device was evaluated.

RESULTS

Statistically significant differences (P <0.05) were observed between PTVs made by the two EPT devices. PTVs measured by the wireless EPT device were significantly higher than the cabled EPT device (P <0.05), indicating lower implant stability. The intraobserver reliability of the wireless EPT device was evaluated as excellent for the measurements in type II bone and good-to-excellent in type IV bone; interobserver reliability was evaluated as fair-to-good in both bone types.

CONCLUSION

The wireless EPT device gives PTVs higher than the cabled EPT device, indicating lower implant stability, and its inter- and intraobserver reliability is good and acceptable.

The Evaluation of the Reliability of Periotest for Implant Stability Measurements: An In Vitro Study

Periotest (Medizintechnik Gulden, Modautal, Germany) is a widely accepted implant stability measurement method, although the reliability is not well known. The aim of this in vitro study was to investigate the reliability of the Periotest in implant stability measurements. Thirty implants were placed in 3 cow ribs. The stability of each implant was measured by insertion torque, resonance frequency analyses, and Periotest and then compared. The Periotest values (PTVs) were measured by 4 different examiners. The measurements were repeated twice in both the buccal and mesial directions, for each implant at 2-hour intervals and the intra- and interobserver reliability of Periotest was measured. Results showed that the intraobserver reliability of the Periotest was excellent for the buccal PTVs but fair to poor for the mesial PTVs. The interobserver reliability of the Periotest was excellent for the buccal PTVs but poor for the mesial PTVs. No significance was found between the PTVs and IT values (P = .803) and PTVs and ISQ values, whereas a 47.1% significant correlation was detected between the IT values and ISQ values (P = .009). The present study indicates that only Periotest measurements from buccal result in excellent intra- and interobserver reliability for the quantification of the implant stability.

Assessment of Osstell ISQ's reliability for implant stability measurement: a cross-sectional clinical study

Resonance frequency analysis (RFA) allows assess implant stability by measuring implant oscillation frequency on the bone. RFA is an objective and non-invasive method for implant stability measurement, although scarce evidence has been provided so far on its reliability. Objectives: Assess the Osstell ISQ system’s reliability (i.e., its measurement reproducibility and repeatability) by means of the intraclass correlation coefficient (ICC) as statistical method. Study Desing: Implants stability registers were completed by means of Osstell ISQ on 85 implants on 23 patients. Six measurements were completed on each implant by means of two different SmartPegs (types I and II); that is, three consecutive measurements with each transducer. Results: Average ISQ was 72.40, 72.22 and 72.79, and 72.06, 72.59 and 72.82 in the first, second, and third measurements with SmartPegs I and II, respectively. Equal values or differences below three ISQ points were observed in 52.9% and 62.4% of the cases with SmartPegs I and II, respectively. The intraclass correlation coefficient was 0.97 for both SmartPegs, and repeatability and reproducibility also reached 0.97 for both SmartPegs. Conclusions: The RFA system Osstell ISQ presents almost perfect repeatability and reproducibility after intraclass correlation coefficient analysis. Osstell ISQ measurements are highly reliable regarding reproducibility. Therefore, one measurement proves enough.

Key words:Dental implants, RFA, ISQ, implant stability, Osstell.

Estudo in vitro da influência do formato e do tratamento de superfície de implantes odontológicos no torque de inserção, resistência ao arrancamento e frequência de ressonância

OBJETIVO: A proposta do estudo foi avaliar a influência do formato e do tratamento de superfície na estabilidade primária de implantes odontológicos, inseridos em diferentes substratos, utilizando-se associação de métodos, como torque de inserção, resistência ao arrancamento e frequência de ressonância. MATERIAL E MÉTODO: Foram utilizados 32 implantes da marca Conexão® (Conexão Sistemas de Prótese Ltda, Arujá, São Paulo, Brasil), sendo: oito cilíndricos com tratamento Porous (CA), oito cilíndricos usinados (MS), oito cilíndricos tratamento duplo Porous (MP) e oito cônicos sem tratamento (CC). Os substratos utilizados para inserção foram: costela de porco; poliuretana Synbone©; poliuretana Nacional® (15, 20, 40 PCF), e madeira. O torque de inserção (TI) foi quantificado utilizando-se um torquímetro digital Kratos®; a força de arrancamento (RA) foi aferida por meio de tração axial, realizada em uma Máquina Universal de Ensaios (Emic® DL-10000), e utilizou-se também análise por meio de frequência de ressonância (RF). Para obtenção dos resultados estatísticos, utilizou-se análise de variância e teste de Tukey (significância de 5%). RESULTADO: Ao analisar o torque de inserção, verificou-se que os implantes com tratamento de superfície não foram diferentes estatisticamente dos usinados, assim como os implantes cilíndricos não tiveram diferença dos cônicos em todos os substratos (p>0,05), com exceção da poliuretana Synbone©. Em relação à resistência ao arrancamento, os implantes tratados e usinados, assim como cônicos e cilíndricos, não tiveram diferença estatística (p>0,05); a análise de frequência de ressonância mostrou que não houve diferença entre os implantes (p>0,05), com exceção da poliuretana Nacional® (20 PCF). CONCLUSÃO: Os formatos e o tratamento de superfície estudados não demonstraram valores significantes quando foram comparados os implantes entre si e, considerando os substratos avaliados, não houve diferença estatística entre os diferentes tipos de implantes.

Analysis of primary stability of dental implants inserted in different substrates using the pullout test and insertion torque

The aim of the study was to evaluate mechanical behavior of implants inserted in three substrates, by measuring the pullout strength and the relative stiffness. 32 implants (Master Porous-Conexao, cylindrical, external hexagon, and surface treatment) were divided into 4 groups (n = 8): pig rib bone, polyurethane Synbone, polyurethane Nacional 40 PCF, and pinus wood. Implants were installed with the exact distance of 5 mm of another implant. The insertion torque (N·cm) was quantified using the digital Kratos torque meter and the pullout test (N) was performed by an axial traction force toward the long axis of the implant (2 min/mm) through mount implant devices attached to a piece adapted to a load cell of 200 Kg of a universal testing machine (Emic DL10000). Data of insertion torque and maximum pullout force were submitted to one-way ANOVA and Bonferroni tests (α = 0.05). Polyurethane Nacional 40 PCF and pinus wood showed the highest values of insertion torque and pullout force, with significant statistical difference (P < 0.05) with other groups. The analysis showed stiffness materials with the highest values for primary stability.

Resonance frequency analysis-reliability in third generation instruments: Osstell mentor®

Few studies assess repeatability and reproducibility in registers of resonance frequency analysis (a value of dental implant stability).

OBJECTIVE

Few studies assess repeatability and reproducibility in resonance frequency analyses (implant stability evaluation). This study is aimed at assessing reliability (repeatabilty and reproducibility) in the Osstell Mentor® system using the intraclass correlation coefficient (ICC) as the statistical method.

STUDY DESIGN

ISQ measurements of RFA were carried out by means of the Osstell Mentor® instrument in 58 implants in 19 patients. Six measurements were performed on each implant by means of two different Smart-Pegs (I and II). Three consecutive measurements were registered with each transducer.

RESULTS

Average ISQ varied from 72.43 to 72.60 and 73.26 in the first, second and third measurements, respectively with the SamrtPeg I and from 72.98 to 73.26 and 73.74 in the first, second and third measurements, respectively with the SamrtPeg II . Exactly equal values were observed in 10.43 and 12.1% of the cases with Smart-Pegs I and II, respectively. The intraclass correlation coefficient was 0.96 and 0.96 for Smart Pegs I and II, respectively. Repeatability and reproducibility was 0.97 for both Smart-Pegs I and II.

CONCLUSIONS

The RFA system contributed by Osstell Mentor® renders almost perfect reproducibility and repeatability, as proven by statistical analysis carried out by means of ICC with 95% confidence level. This instrument contributes highly reliable RFA measurements in dental implants.

Influence of surgical technique, implant shape and diameter on the primary stability in cancellous bone

Achievement of primary stability during surgical placement of dental implants is one of the most important factors for successful osseointegration depending on various anatomical, surgical and implant-related factors. Resonance frequency analysis (RFA) has been shown as a non-invasive and objective technique for measuring the stability of implants. The aim of this study was to evaluate the effect of some surgical and implant-related factors in enhancing primary stability and to estimate a correlation between RFA and insertion torque (IT) in proximal regions of cow ribs representing cancellous bone. Fifteen implant beds were prepared in the most proximal region of six fresh cow ribs. Ninety implants with three different shapes and two different diameters were placed with two different surgical techniques, and the primary stability was compared using RFA and IT. Significantly higher RFA and IT values were achieved when under-dimensioned drilling was used as the surgical method (P<0·01); significantly higher IT values were obtained with the use of wider implants (P<0·01) and partially conical Astra Tech implants showed the highest IT values (P<0·01). When all the implants were considered, significant correlations between the IT and RFA values were noted (%40·6, P<0·05). Partially conical implants with a wide diameter to be placed with the modified surgical technique proposed appear to be useful in enhancing the primary stability in cancellous bone.