A comparison of implant stability quotients measured using magnetic resonance frequency analysis from two directions: a prospective clinical study during the initial healing period

Resonance frequency analysis with two different devices after conventional implant placement with ridge preservation: A prospective pilot cohort study

BACKGROUND

Primary and secondary implant stability is of high importance for survival and success of dental implants in the short and long term. Measurements of implant stability during healing provide the opportunity to monitor the course of the osseointegration process.

PURPOSE

To compare implant stability quotient (ISQ) by resonance frequency analysis (RFA), recorded with two different devices after implant placement.

MATERIALS AND METHODS

Patients with the need of single tooth extraction in posterior sites of the maxilla and the mandible were treated in a surgical center. All patients received additional augmentation with a bovine bone substitute and platelet-rich fibrin (PRF) after atraumatic tooth extraction. After a healing period of 10 weeks, 28 self-tapping titanium-implants were placed. Implant stability was recorded with two different devices (Osstell and Penguin) at the time of implant insertion (T0), 10 days later (T1), and after 7 (T2), or 17 weeks (T3).

RESULTS

No implant was lost, and no postoperative complication occurred during follow-up. Patient cohort comprised 9 female (32.1%) and 19 male patients (67.9%), with a mean age of 52.8 years, 64.3 years, respectively. Mean overall insertion torque was 43.6 Ncm at implant placement with no significant difference between implant location, age, or gender. No patient dropped out. During observation period, a significant increase in mean ISQ was recorded with both devices. Significant positive correlations between insertion torque and ISQ were recorded with both devices at T0, T2, and T3. No significant differences were observed in ISQ-values between both devices, and measuring directions at any point of measurement.

CONCLUSIONS

Within the limitations of this cohort study, both devices were suitable for RFA-measurement and revealed comparable results. Due to the cordless design, handling of the Penquin device was more comfortable. Reusability of the Penguin MultiPeg-transducers may offer an additional benefit with regard on ecological aspects.

Factors Affecting Implant Stability Quotients at Immediately and Conventionally Loaded Implants in the Posterior Maxilla: A Split-Mouth Randomized Controlled Trial

PURPOSE

To assess primary and secondary stability of variable-thread tapered implants in the posterior maxilla and analyze the impact of various factors on implant stability quotients (ISQs).

MATERIALS AND METHODS

Twenty-six subjects received 3-4 adjacent implants in the maxillary premolar-molar sextants to replace bilateral tooth loss. The implants on one side were immediately loaded with a provisional fixed prosthesis regardless of their primary stability. The contralateral control implants were conventionally loaded. Bone quality was subjectively recorded and primary stability was assessed by means of insertion torque values (ITVs) and ISQs in 4 directions. Secondary stability was measured by ISQ at definitive prosthesis delivery (3-3.5 months postoperatively), and 12 months after definitive loading. The impact of measurement direction, loading protocol, time, site-related (bone quality, implant position, crestal buccal bone thickness, apical cortical anchorage), and implant-related (implant dimensions, abutment height) variables on ISQs was assessed.

RESULTS

For logistic reasons, ISQs were obtained for only 18 patients with 60 test and 60 control implants. Most of the implants (82%) at baseline had their lowest ISQ on the buccal aspect. There were no significant differences between ISQs measured in the buccal and palatal directions, or between ISQs in the mesial and distal directions. The mean of buccal and palatal ISQs was significantly lower than the mean of the 2 interproximal measurements at all evaluation periods. ISQs were not significantly different between the 2 loading groups at any time point. All implants showed a time-dependent increase in ISQs. Baseline ISQ correlated weakly with bone quality and ITV. None of the variables had a significant impact on baseline ISQs, except for implants in second molar sites which showed poorer primary stability than first premolars.

CONCLUSION

Measurement direction and time are the most significant parameters affecting ISQs of variable-thread tapered implants in the posterior maxilla.

Comparison of regular- and slope-configured dental implants placed in the edentulous ridge with height discrepancy: A pilot randomized controlled trial

BACKGROUND/PURPOSE

Edentulous ridges with height discrepancies (RHDs) could jeopardize the outcome of implant placement. This study aimed at evaluating the outcomes of placing regular- and slope-configured implants in RHDs.

METHODS

Patients with >1 mm RHDs requesting implant rehabilitation were recruited and randomly assigned to regular- (control) or slope-configured (test) implant treatment using a submerged installation protocol. Thread exposure (TE) and implant stability quotient (ISQ) were evaluated during implant installation (S1) and uncovered surgery (S2), and marginal bone level (MBL) was evaluated after implant installation (T1) and uncovery (T3), and one year after implant placement (T4). Periodontal status and gingival crevicular fluid (GCF) biomarkers of adjacent teeth were evaluated before implant installation (T0), before uncovery (T2), and at T4. Peri-implant clinical status and peri-implant crevicular fluid (PICF) biomarkers of examined implants were evaluated at T4.

RESULTS

Nineteen patients with 17 control and 13 test implants were included. All of the implants survived with acceptable peri-implant health, and PICF biomarkers were at equivalent levels as GCF biomarkers of the adjacent teeth at T4. Compared with the control group, the test group showed reduced TE and equivalent ISQ at S1 and S2, and the loss of MBL was reduced at T4. Regarding the adjacent teeth, all periodontal parameters and GCF biomarkers were slightly decreased from T0 to T2, and the reductions in probing pocket depth and clinical attachment level were slightly greater at T4.

CONCLUSION

Slope-configured implants maintained the implant-supporting structures and minimally altered periodontal status of the adjacent teeth in RHDs.

The clinical significance of implant stability quotient (ISQ) measurements: A literature review

Implant stability quotients (ISQ values) are obtained in dental clinical practice on a non-invasive basis by resonance frequency measurement rapidly after surgical placement of implants. The ISQ-values are used as indicator for mechanical implant stability, and are believed to have predictive power for clinical outcome. It is the aim of this review to provide a synopsis of all factors described in the literature that influence ISQ measurements by performing an exhaustive literature review; moreover, this review aims at elucidating the key factors relevant for a rapid clinical predictive assessment. We searched systematically and exhaustively all major databases for publications relating to ISQ measurement methodology and for ISQ-influencing factor analyses. The reports identified were ordered in experimental (preclinical) studies and in clinical publications. We were able to identify 13 basic factors influencing ISQ-measurements. Among these, local bone quality, playing a key role in such measurements, was subdivided in four specific subfactors; thus a total of 17 individual factors was identified and reported to influence ISQ-measurements. A comprehensive list of these factors is provided in Table-form. A critical analysis points out that only 6 of these factors are of a sound predictive power useful for a rapid clinical assessment; and only two of these factors appear to have a well-documented scientific basis.

Relationship between Implant Length and Implant Stability of Single-Implant Restorations: A 12-Month Follow-Up Clinical Study

Background and Objectives: Implant stability in vivo is contingent on multiple factors, such as bone structure, instrument positioning and implant surface modifications, implant diameter, and implant length. Resonance-frequency analysis is considered a non-invasive, reliable, predictable, and objective method by which to evaluate implant stability, due to its correlation with bone-to-implant contact. The purpose of this study was to evaluate the effect of implant length on the primary and secondary stability of single-implant crown rehabilitations, as measured by resonance-frequency analysis at different times. Materials and Methods: Implants of 10 and 11.5 mm were placed, and the resonance frequency was measured at the time of surgery (T0), as well as at 3 (T1), 6 (T2), and 12 (T3) months post-surgery. Results: A total of 559 implants were placed in 195 patients. Significant differences were observed when comparing the implant stability quotient (ISQ) values at T1, with values for 10-mm implants being greater than those for 11.5-mm implants (p = 0.035). These differences were also observed when comparing ISQ values for buccal and lingual areas. At T0, T2, and T3, no significant differences in ISQ values were observed. The use of 10-mm implants in the anterior maxilla yielded significantly greater values at T0 (p = 0.018) and T1 (p = 0.031) when compared with 11.5-mm implants. Significant differences in measurements were observed only for buccal areas (p = 0.005; p = 0.018). When comparing the sample lengths and sex, women with 11.5-mm implants showed significantly lower results than those with 10-mm implants (p < 0.001). Conclusions: There is a direct relationship between implants of a smaller length and greater ISQ values, with this relationship being most evident in the maxilla and in women.

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.

Comparative evaluation of implant stability in two different implant systems at baseline and 3-4 months intervals using RFA device (OSSTELL ISQ)

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.

Effect of implant macrogeometry on peri-implant healing outcomes: a randomized clinical trial

OBJECTIVES

This randomized split-mouth clinical trial investigated the influence of implant macrogeometry on bone properties and peri-implant health parameters during the healing process.

MATERIAL AND METHODS

Ninety-nine implants were placed bilaterally in posterior mandibles of 23 patients that received at least four dental implant macrogeometries: standard geometry, Integra (IN) and three geometries inducing "healing chamber": Duo (D), Compact (C), and Infra (IF). Insertion torque (IT) and implant stability quotient (ISQ) were measured. Peri-implant health were monitored by visible plaque index (VPI), peri-implant inflammation (PI), and presence of calculus (CC). Data were collected during 90 days. Data were assessed for normality using the asymmetry and kurtosis coefficients followed by the Shapiro-Wilk test. A one-way ANOVA was used to investigate differences in IT and linear bone dimensions between the macrogeometry groups. The repeated measurements ANOVA test or ANOVA-R was used for analysis of ISQ, VPI, and PI. Tukey-Kramer test or Student's t test was used for comparisons between the groups or within each macrogeometry.

RESULTS

Macrogeometry did not significantly influence IT and ISQ values. The minimum ISQ was recorded after 7 days (71.95 ± 12.04, p = 0.0001). Intermediate ISQ was found after 14 days, when the ISQ reached values that are statistically identical to primary stability. The VPI showed significantly higher scores for the D (0.88 ± 1.03) and IN (0.72 ± 0.94) implants after 7 days. The PI was only influenced by the healing time significantly decreasing from 7 (1.07 ± 0.89) to 21 days (0.18 ± 0.18).

CONCLUSION

Implant macrogeometry did not influence IT nor ISQ values. The relationship between IT and SS was more evident for the Duo implant, but only in the final stage of healing process.

CLINICAL RELEVANCE

Show to the clinician that the macrogeometry and drilling protocols did not interfere in the clinical behavior of the implants during the healing process. However, the IT, primary and secondary stability, is quite dependent of the surgeon experience.

The effect of 2 versus 4 implants on implant stability in mandibular overdentures: A randomized controlled trial

STATEMENT OF PROBLEM

Dental research is rich with articles that investigated the influence of host-site variables, some implant-related variables (implant length, diameter, taper, design, location, and surface topography), different loading protocols or surgical procedures, and measurement methodology on dental implant stability. However, the number of implants and its effect on implant stability remain unclear.

PURPOSE

The purpose of this randomized clinical trial was to investigate the influence of implant number on implant stability by comparing 2 versus 4 implants in mandibular implant overdentures.

MATERIAL AND METHODS

The trial included 20 participants with edentulous mandibular ridges. Participants were randomly assigned to 2 equal groups, a 4-implant (experimental) group consisting of 4 implants installed in lateral-canine and premolar regions; and a 2-implant (control) group, consisting of 2 implants in lateral-canine regions. Implant stability was measured using resonance frequency analysis at implant placement and then at 1, 3, 6, 9, and 12 months. The Student t test was used to compare the implant stability quotient (ISQ) values of the anterior implants in the 4-implant and 2-implant groups. One-way ANOVA followed by the post hoc Bonferroni test was used to compare ISQ values among the different follow-up periods within each group (α=.05).

RESULTS

Mean ISQ values for anterior implants in the 4-implant group were slightly higher than those recorded for the 2-implant group at all follow-up periods. However, these differences were not statistically significant (P>.05). Within-group comparison revealed an initial decrease in implant stability for all implants. This decrease was statistically significant for the 2-implant group (P<.001) and for posterior implants in the 4-implant group (P<.001). This was then followed by a gradual increase in ISQ values for all implants in both groups.

CONCLUSIONS

Increasing the number of implants from 2 to 4 in mandibular implant overdentures did not have a significant influence on implant stability.

The Effect of Ridge Expansion on Implant Stability in Narrow Partially Edentulous Ridges - A Preliminary Clinical Study

INTRODUCTION

Currently, dental treatments with better aesthetic results and less treatment time is more acceptable by the patients. Inadequate amount of bone for implant placement at functionally and aesthetically most appropriate position is a common problem.

AIM

To assess the effect of ridge expansion on implant stability in narrow partially edentulous ridges and to evaluate clinically and radiographically the success of dental implants, placed immediately following ridge expansion procedure.

MATERIAL AND METHODS

Ten participants (nine males, one female, average age - 28 years) with partial edentulism associated with narrow atrophic alveolar ridges with adequate height and willing to participate in the study were included. The ridge expansion was performed using osteotomes and simultaneous implant placement was done. A total of 10 implants were placed. Stability, achieved ridge width and radiographic crestal bone loss were assessed three months post-operatively.

RESULTS

Three months follow-up revealed stable implants both clinically and radiographically. All 10 implants were surrounded by adequate amount of bone required for successful functional rehabilitation.

CONCLUSION

The study reveals that the technique of ridge expansion using osteotomes is successful in horizontal expansion, in cases of atrophic alveolar ridges thus, eliminating the need for more complex treatment as well as reduces the rehabilitation time along with improving the quality of bone support.

Longitudinal implant stability measurements based on resonance frequency analysis after placement in healed or regenerated bone

Primary stability is an indicator of subsequent osseointegration of dental implants. However, few studies have compared the implant stability among anatomical regions and bone types; thus, not enough data exist regarding the stability of implants placed in regenerated bone (RB). The present study evaluated primary and long-term stability of implants placed in RB and non-regenerated healed bone (HB). A total of 216 screw cylinder implants were placed in 216 patients (98 in HB and 118 in RB, 6 [RB6, N = 68] or 12 [RB12, N = 50] months after tooth extraction). Implant stability was evaluated using resonance frequency analysis (RFA) measured at the time of implant placement (E1), at the time of loading (4 months after placement, E2), and 4 months after loading (E3). Various clinically relevant measurements were obtained, such as implant diameter, length, and location, as well as bone quality. At E1, implant location, bone quality, and experimental group significantly affected implant stability (all at P < .05). At E2, implant location, diameter, length, and experimental group significantly affected implant stability (all at P < .05). At E3, bone quality, implant diameter, length, and experimental group significantly affected implant stability (all at P < .01). Stability for the RB12 group was significantly higher than all other corresponding values; further, the values did not change significantly over time. For the HB and RB6 groups, stability was significantly higher at E2 than at E1 (P < .001) and was no different between E2 and E3. Implant location, length, and experimental group were associated with these differences (all at P < .05). Compared with HB and RB6, higher implant stability may be achieved in regenerated bone 12 months post-extraction (RB12). This stability was achieved at E1 and maintained for at least 8 months. Variables such as implant length, diameter, and bone quality affected the stability differently over time. Implant stability varied in different anatomic regions and with regard to different healing processes in the bone.

Mini-implant stability at the initial healing period: a clinical pilot study

OBJECTIVE

To evaluate the changes of mini-implant stability over the initial healing period in humans.

MATERIAL AND METHODS

A sample of 19 consecutively treated patients (mean age 15.5 ± 7.3 years) was examined. In each patient, a mini-implant of a size of 2 × 9 mm was inserted into the anterior palate. Implant stability was assessed using resonance frequency analysis (RFA) immediately after insertion (T0), 2 weeks later (T1), 4 weeks later (T2), and 6 weeks later (T3). Insertion depth (ID) and the maximum insertion torque (IT) were measured. Data were tested for correlations between RFA, ID, and IT. All RFA values were tested for statistically significant differences between the different times.

RESULTS

The mean ID was 7.5 ± 0.6 mm, and the mean IT was 16.8 ± 0.6 Ncm. A correlation was found between RFA and ID (r = .726, P < .0001), whereas no correlations between RFA and IT or between IT and ID were observed. From T0 to T1, the stability (36.1 ± 6.1 implant stability quotient [ISQ]) decreased nonsignificantly by 4.9 ± 6.1 ISQ values (P > .05). Between T1 and T2, the stability decreased highly significantly (P < .001) by 7.9 ± 5.9 ISQ values. From T2 on, RFA remained nearly unchanged (-1.7 ± 3.5 ISQ; P > .05).

CONCLUSIONS

Mini-implant stability is subject to changes during the healing process. During weeks 3 and 4, a significant decrease of the stability was observed. After 4 weeks, the stability did not change significantly.

Factors influencing resonance frequency analysis assessed by Osstell mentor during implant tissue integration: II. Implant surface modifications and implant diameter

OBJECTIVES

To monitor the development of the stability of Straumann tissue-level implants during the early phases of healing by resonance frequency analysis (RFA) and to determine the influence of implant surface modification and diameter.

MATERIAL AND METHODS

A total of twenty-five 10 mm length implants including 12 SLA RN v4.1 mm implants, eight SLActive RN v4.1 mm implants and five SLA WN v4.8 mm implants were placed. Implant stability quotient (ISQ) values were determined with Osstell mentor at baseline, 4 days, 1, 2, 3, 4, 6, 8 and 12 weeks post-surgery. ISQ values were compared between implant types using unpaired t-tests and longitudinally within implant types using paired t-tests.

RESULTS

During healing, ISQ decreased by 3-4 values after installation and reached the lowest values at 3 weeks. Following this, the ISQ values increased steadily for all implants and up to 12 weeks. No significant differences were noted over time. The longitudinal changes in the ISQ values showed the same patterns for SLA implants, SLActive implants and WB implants. At placement, the mean ISQ values were 72.6, 75.7 and 74.4, respectively. The mean lowest ISQ values, recorded at 3 weeks, were 69.9, 71.4 and 69.8, respectively. At 12 weeks, the mean ISQ values were 76.5, 78.8 and 77.8, respectively. The mean ISQ values at all observation periods did not differ significantly among the various types. Single ISQ values ranged from 55 to 84 during the entire healing period. Pocket probing depths of the implants ranged from 1 to 3 mm and bleeding on probing from 0 to 2 sites/implant post-surgically.

CONCLUSIONS

All ISQ values indicated the stability of Straumann implants over a 12-week healing period. All implants showed a slight decrease after installation, with the lowest ISQ values being reached at 3 weeks. ISQ values were restored 8 weeks post-surgically. It is recommended to monitor implant stability by RFA at 3 and 8 weeks post-surgically. However, neither implant surface modifications (SLActive) nor implant diameter were revealed by RFA.