Mean Implant Stability Quotient Values Research Articles

Clinical efficacy of the graft free slit-window sinus floor elevation procedure: A 2-year randomized controlled clinical trial.

Slit-window technique is a lateral approach sinus floor elevation (SFE) procedure that utilizes a rigid resorbable membrane in conjunction with stabilizing bony slits to tent the Schneiderian membrane without addition of grafting materials. The aim of this randomized clinical trial was to compare clinical and radiographic outcomes of the Slit-window SFE with those of SFE with bone grafting. Thirty-three patients with 38 edentulous sites were included. Edentulous sites were randomly allocated to the Slit-window SFE or SFE with bone grafting. Simultaneous with SFE, each site received two dental implants. Implant stability quotient (ISQ) values were recorded at baseline and monthly visits for 8months. The bone coverage and bone height gain at implant sites were recorded on cone beam computed tomography (CBCT) scans 6 and 24months postoperatively. There were no significant differences in the mean ISQ values between the groups at any time point (p>0.05). All implants in both groups were found to have complete bone coverage. Significant increases in the bone height were found 6 and 24months postoperatively in both groups (p<0.001). Within limitations of the present study, it can be concluded that the Slit-window SFE technique without the need for bone grafting resulted in sufficient bone height gain around implants placed simultaneous with the SFE procedures. The bone height around these implants was stable during the 2-year follow-up period. The treatment outcomes for these implants were comparable to those placed simultaneous with lateral approach SFE in conjunction with bone grafting.

Using Resonance Frequency Analysis to Compare Delayed and Immediate Progressive Loading for Implants Placed in the Posterior Maxilla: A Pilot Study

Objective:Implants placed in the posterior region of the maxilla have a high incidence of implant failure due to poor bone quality, especially when immediate implant loading is needed. Immediate Progressive Loading (IPL) can enhance bone quality and may offer an alternative solution when Immediate Implant loading is needed.Methods:Six patients (one male and five females; 34-62 years old) were included in this study. Twelve implants were inserted in the posterior region of the maxilla. Resonance Frequency Analysis (RFA) was performed at the time of implant placement and after 1, 2, 3 and 6 months. ISQ (Implant Stability Quotient) values were compared between the Delayed Loading (DL) group after 2 months and the Progressive Loading (PL) group and between different time points for each group.Results:At implant placement, the mean ISQ values for PL and DL implants were 63 and 57, respectively. One month after implant placement, the mean ISQ value for PL implants was 73.Two months after implant placement, the mean ISQ value for PL implants was 75. Three months after implant placement, the mean ISQ values for PL and DL implants were 76 and 69, respectively. Six months after implant placement, the mean ISQ values for PL and DL implants were 79 and 76, respectively.Conclusion:Despite its limitations, this pilot study indicated that compared to DL, PL can enhance bone density and implant stability, resulting in greater early functionality and fewer surgery sessions.

Effect of soft laser on osseointegrated dental implants supported maxillary overdenture

Background/ Aim: Many difficulties are encountered in providing a successful single complete denture treatment. Among these problems are the ways to provide comfort, function, proper esthetics and retention for the maxillary complete dentures in patients with opposing natural dentition. The aim of this study deals with successful rehabilitation of edentulous maxillary ridge (split-mouth technique) opposing a natural teeth prosthetically, retained with dental implants in the canine and posterior regions, using a flapless surgical technique, with an exposure of Low Level Laser Therapy (LLLT) after implant installment in order to evaluate its influence on the osseionegration, implant stability was evaluated using periotest at time of loading, 4 months and 6 months later to show the early success of dental implants placed into low- density bone. Also bone changes was evaluated by using digital periapical radiography with paralleling technique.Materials and methods: Following the split-mouth design, dental implants were inserted in the maxilla of 6 patients, the right side dental implants received LLLT ( laser side) with an output power of 0.5 UT and continuous mode was used to receive a total dose of 30 J per implant over 60 seconds, while the other side was the control side. The soft laser treatment was performed immediately after the surgery, 3 days and a week after surgery, then evaluated for stability during the follow-up period (at time of loading, 4 months and 6 months later) using periotest ,and further bone height changes using digital radiograph.Results: irradiated implants achieved a higher stability compared with control group during the entire follow-up period. At base line and after 4 months; there was no statistically significant difference between implant stability quotient (ISQ) values in the two sides. After 6 months; laser side showed statistically significantly higher mean ISQ values than control side.Conclusion: the present investigation demonstrated that 6 months after soft laser application significantly positively influenced implant stability and bone height around dental implants.

Relationship between cortical bone thickness and implant stability at the time of surgery and secondary stability after osseointegration measured using resonance frequency analysis.

PurposeIt has been suggested that resonance frequency analysis (RFA) can measure changes in the stability of dental implants during osseointegration. This retrospective study aimed to evaluate dental implant stability at the time of surgery (primary stability; PS) and secondary stability (SS) after ossseointegration using RFA, and to investigate the relationship between implant stability and cortical bone thickness.MethodsIn total, 113 patients who attended the Tohoku University Hospital Dental Implant Center were included in this study. A total of 229 implants were placed in either the mandibular region (n=118) or the maxilla region (n=111), with bone augmentation procedures used in some cases. RFA was performed in 3 directions, and the lowest value was recorded. The preoperative thickness of cortical bone at the site of implant insertion was measured digitally using computed tomography, excluding cases of bone grafts and immediate implant placements.ResultsThe mean implant stability quotient (ISQ) was 69.34±9.43 for PS and 75.99±6.23 for SS. The mandibular group had significantly higher mean ISQ values than the maxillary group for both PS and SS (P<0.01). A significant difference was found in the mean ISQ values for PS between 1-stage and 2-stage surgery (P<0.5). The mean ISQ values in the non-augmentation group were higher than in the augmentation group for both PS and SS (P<0.01). A weak positive correlation was observed between cortical bone thickness and implant stability for both PS and SS in all cases (P<0.01).ConclusionsBased on the present study, the ISQ may be affected by implant position site, the use of a bone graft, and cortical bone thickness before implant therapy.

Low-level laser therapy with 940nm diode laser on stability of dental implants: a randomized controlled clinical trial.

Low-level laser therapy (LLLT) is a non-invasive modality to promote osteoblastic activity and tissue healing. The aim of this study was to evaluate the efficacy of LLLT for improvement of dental implant stability. This randomized controlled clinical trial was performed on 80 dental implants placed in 19 patients. Implants were randomly divided into two groups (n=40). Seven sessions of LLLT (940nm diode laser) were scheduled for the test group implants during 2weeks. Laser was irradiated to the buccal and palatal sides. The same procedure was performed for the control group implants with laser hand piece in "off" mode. Implant stability was measured by Osstell Mentor device in implant stability quotient (ISQ) value immediately after surgery and 10days and 3, 6, and 12weeks later. Repeated measures ANOVA was used to compare the mean ISQ values (implant stability) in the test and control groups. Statistical test revealed no significant difference in the mean values of implant stability between the test and control groups over time (P=0.557). Although the mean values of implant stability changed significantly in both groups over time (P<0.05). Although the trend of reduction in stability was slower in the laser group in the first weeks and increased from the 6th to 12th week, LLLT had no significant effect on dental implant stability.

Immediate loading of two flapless placed mandibular implants supporting cross‐arch fixed prostheses: a 5‐year follow‐up prospective single cohort study

Purpose To evaluate the clinical outcome of two implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses 5 years after loading. Materials and methods Eighty consecutive patients were recruited. To be immediately loaded, implants had to be inserted with a minimum torque of 80 Ncm. Forty-six laser-welded titanium and 34 cast silver-palladium frameworks with resin teeth were initially delivered within 8 and 48 h, respectively. Outcome measures, evaluated by two independent assessors included prosthesis and implant failures, complications, marginal bone level changes, implant stability quotient (ISQ) values and patient satisfaction. Results Five years after loading one patient did not return to the control and 10 prostheses were remade. Two implants failed early in two patients, but they were successfully replaced. Thirty-six complications occurred in 28 patients but were all successfully treated. After 5 years, mean marginal bone loss was 0.69 mm, mean ISQ values decreased from 75.4 to 73.8, and all patients were fully satisfied with the therapy. A post-hoc comparison between the outcome of laser-welded and cast frameworks showed that laser-welded frameworks were affected by significantly more complications (19 patients out of 46 and 6 patients out of 34, respectively; difference in proportion = 0.23, 95% CI: 0.03 to 0.43; Pearson's chi-square test, P = 0.032), therefore such a framework construction should be considered as a long-term temporary prosthesis and not a definitive prosthesis. Conclusions Immediately loaded mandibular cross-arch prostheses can be supported by only two implants up to 5 years, if made with a robust cast framework. Longer follow-ups (around 10 years) are still needed to know the prognosis of this treatment modality.

Minimally Invasive Sinus Augmentation Procedure Using a Dedicated Hydraulic Sinus Lift Implant Device: A Prospective Case Series Study on Clinical, Radiologic, and Patient-Centered Outcomes.

The aim of this study was to evaluate clinical and radiologic outcomes of a novel device that allows simultaneous hydraulic sinus membrane elevation, bone grafting, and implant placement. A sample of 18 consecutive participants with severe atrophy of the posterior maxilla underwent transcrestal elevation of the sinus membrane and implant placement. At the 6-month follow-up, the following parameters were assessed: implant success, any complications, marginal bone loss (MBL), three-dimensional (3D) graft measurements, implant stability quotient (ISQ), and graft density. No implants failed during follow-up (10.8 ± 2.8 months; range: 7-14 months). No membrane tears or other adverse events were observed. Mean residual alveolar ridge height was 4.78 ± 0.88 mm. Six months after the procedure, the mean MBL was 0.18 mm. The mean sinus membrane elevation was 12.78 ± 2.18 mm (range: 10.7-14.23). Along the basic 3D reference planes, the dimensions of grafted bone measured around implants were as follows: axial area = 239.7 ± 57.68 mm2; sagittal area = 257.0 ± 60.83 mm2; coronal area = 143.3 ± 29.46 mm2. The mean volume of the graft was 2.38 ± 0.26 mL at baseline and 2.05 ± 0.24 mL 6 months after graft maturation (difference: 0.33 ± 0.29 mL, P = .0090). Graft density (in Hounsfield units [HU]), improved during healing from 322.0 ± 100.42 HU to 1,062.0 ± 293.7 HU; difference 740.0 ± 295.35 HU (P = .0001). The mean ISQ value was 65.5 at implant placement, and it increased to 74.1 at the 6-month examination (P = .0014). Of 18 patients, 12 experienced no pain (66.6%) and 10 experienced no swelling (55.5%). No severe pain or swelling was reported in any of the cases. The mean number of analgesic tablets consumed was 0.78 ± 0.67. Mean surgical time was 24.0 ± 4.07 minutes. The iRaise Sinus Lift System may provide a new option for minimally invasive transcrestal sinus surgery with minimal patient discomfort. A physiologic contraction of 13.9% of its original volume was experienced during healing. Long-term clinical studies are needed to confirm these preliminary results.

A resonance frequency analysis of sandblasted and acid-etched implants with different diameters: a prospective clinical study during the initial healing period.

PurposeThe possibility of immediate or early loading has become popular in implant dentistry. A prerequisite for the immediate or early loading of an implant prosthesis is the achievement of initial stability in the implant. Moreover, in response to clinicians' interest in verifying clinical stability to determine the optimal time point for functional loading, a non-invasive method to assess implant stability has been developed on the basis of resonance frequency analysis (RFA). The primary objective of this study was to monitor the stability of sandblasted, large-grit, and acid-etched (SLA) implants with different diameters during the early phases of healing by RFA. The secondary objective was to evaluate how the initial stability of implants varied depending on different surface modifications and other contributing factors.MethodsThirty-five implants (25 SLA implants and 10 resorbable blasting media [RBM] implants) placed in 20 subjects were included. To measure implant stability, RFA was performed at baseline and at 1, 2, 3, 4, 6, and 10 weeks after surgery.ResultsThe longitudinal changes in the implant stability quotient (ISQ) values were similar for the SLA implants with different diameters and for the RBM implants. During the initial healing period, the ISQ decreased after installation and reached its lowest values at 1 week and 2 weeks, respectively. The mean ISQ values in the SLA implants were significantly higher in Ø 5.0 mm implants than in Ø 4.0 mm implants. Men showed a higher ISQ than women. Mandibular sites showed a higher ISQ than maxillary sites.ConclusionsAll implants used in this study are suitable for immediate or early loading under appropriate indications. A wider diameter and SLA surface treatment of implants could improve the stability, if the implant is fixed with at least 30 Ncm of insertion torque.

Monitoring the Changes of Material Properties at Bone-Implant Interface during the Healing Process In Vivo: A Viscoelastic Investigation.

The aim of this study was to monitor the changes of viscoelastic properties at bone-implant interface via resonance frequency analysis (RFA) and the Periotest device during the healing process in an experimental rabbit model. Twenty-four dental implants were inserted into the femoral condyles of rabbits. The animals were sacrificed immediately after implant installation or on day 14, 28, or 56 after surgery. Viscoelastic properties at bone-implant interface were evaluated by measuring the implant stability quotient (ISQ) using RFA and by measuring the Periotest values (PTVs) using the Periotest device. The bone/implant specimens were evaluated histopathologically and histomorphometrically to determine the degree of osseointegration (BIC%). The BIC% values at different time points were then compared with the corresponding ISQ values and PTVs. The mean ISQ value increased gradually and reached 81 ± 1.7 on day 56, whereas the mean PTV decreased over time, finally reaching −0.7 ± 0.5 on day 56. Significant correlations were found between ISQ and BIC% (r = 0.701, p < 0.001), PTV and BIC% (r = −0.637, p < 0.05), and ISQ and PTV (r = −0.68, p < 0.05). These results show that there is a positive correlation between implant stability parameters and peri-implant-bone healing, indicating that the RFA and Periotest are useful for measuring changes of viscoelastic properties at bone-implant interface and are reliable for indirectly predicting the degree of osseointegration.

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.

Development of Implant Stability Quotient values of implants placed with simultaneous sinus floor elevation - results of a prospective study with 109 implants.

In patients with implant placement and simultaneous sinus floor elevation (SFE), healing periods of 6months have been the standard of care for more than 25years. The primary objective of this prospective case series study was to determine what percentage of implants placed with SFE reach a threshold Implant Stability Quotient (ISQ) of ≥70 after 8weeks of healing using Resonance Frequency Analysis (RFA). A total of 109 dental implants were placed in 97 patients. SFE was carried out with a lateral window approach and a mixture of autogenous bone chips and deproteinized bovine bone mineral (DBBM). Titanium screw-type, tissue-level implants with a chemically modified SLA surface were used. ISQ values were measured after implant insertion (ISQBL ) and after 8weeks of healing (ISQ8wk ). Patients showing ISQ8wk ≥70 subsequently underwent restoration. Implants with an ISQ value<70 were recalled at 2-week intervals. The ISQ at baseline had a mean value of 68.3 (SD±9.8). At 8weeks, the mean ISQ value was 73.6 (SD±6.4). This increase was statistically significant (P<0.001). An ISQ8wk value ≥70 was observed for 91 implants (83%). One implant (0.9%) with a peri-implant infection and severe bone loss at 8weeks was considered an early failure. This study showed that 83% of implants reached the threshold level of ISQ≥70 after 8weeks, allowing an early loading protocol. The early failure rate was considered low with 0.9%. The RFA technology is a suitable method to objectively monitor implant stability longitudinally.

Effect of Magnetic Field on Bone Healing around Endosseous Implants - An In-vivo Study.

After implant placement, a stress-free healing period of 3-6 months is a pre-requisite to achieve good osseointegration. If this duration could be reduced, the patients would feel happier. Eventhough, immediate loading of implants is a clinically feasible concept; it is not possible in certain situations. Few studies have shown that Static magnetic field is useful to promote bone formation faster after the bone is wounded. This pilot study was intended to evaluate the tissue response after implant placement under the influence of magnetic field. Twenty Tidal Spiral implants were used for this study. Two implants were placed in each patient in the anterior mandible corresponding to the B and D regions and the implant on the D region was exposed to magnetic field using safer magnet (Neodymium Boron Iron) and the implant on the B region served as a control. Both the implants were compared for stability using Resonance Frequency Analyzer (RFA) at Days 0, 30, 60 and 90. Mean Implant Stability Quotient (ISQ) values were compared on both sides using student's paired t-test and repeated measures ANOVA (analysis of variance). There was a significant difference in the mean ISQ values, hence, a post-hoc test was done to evaluate whether there is any difference between the follow-ups. The average ISQ value for implants at 0 day in the B and D regions was 68.6 and 68.7 respectively. The average ISQ value at 30th day, 60th day and 90th day was 73.25, 76.05 and 78.95 respectively on the magnetic side (D region). Whereas on the non-magnetic side (B region) at 30th day, 60th day and 90th day was 68.45, 72.05 and 74.45 respectively. The implant stability quotient values obtained on the magnetic side were significantly greater than on the non-magnetic side. Positive correlation exists between the magnetic field and osseointegration.

Resonance frequency analysis of implants placed with osteotome sinus floor elevation in posterior maxillae.

To test the reliability and validity of implant stability quotient (ISQ) values used for assessment of the condition of bone-to-implant interface in the osteotome sinus floor elevation (OSFE) model and to evaluate the influence of residual bone height (RBH) on ISQ values. Forty-six Straumann(®) tissue-level SLA implants (Φ4.8mm*8mm, wide neck, standard plus) placed in 39 patients applying OSFE without grafting were included in the study. Patients were assigned to three groups based on the RBH with one implant per patient randomly chosen: (1) 2≤RBH<4mm (n=14); (2) 4≤RBH<6mm (n=15); (3) 6≤RBH<8mm (n=10). ISQ values were determined with Osstell ISQ(®) at 0, 2, 4, 8, 12, 16, and 20weeks postoperation. The reliability of RFA measurements was tested by the degree of dispersion of ISQ values at each time point, and the validity was tested by linear correlation between ISQ and RBH. ISQ values were then compared among groups at all observed time points. The implants achieved a mean ISQ value of 63.6 immediately after surgery and reached a higher ISQ level of 70 after 20weeks with a dip at 4weeks. A higher degree of dispersion of ISQ values was observed immediately after surgery compared to the other time points. No significant correlations were found between RBH and ISQ values and no significant difference in ISQ values among groups at all the time points. Within the limits of the study, it may be implied that ISQ values are not able to assess the condition of bone-to-implant interface and the role of single RFA measurement in determining loading protocol is questionable.

Mechanical Versus Biological Stability of Immediate and Delayed Implant Placement Using Resonance Frequency Analysis

The purpose was to objectively measure the stability of immediately placed implants compared with implants placed at healed sites using implant stability quotient (ISQ) values obtained by resonance frequency analysis. Data were collected from 137 Nobel Replace Tapered Groovy Implants placed in 85 patients 19 to 93 years old. All implants were placed by the same surgeon from May 2007 to October 2011. Forty-one implants were placed immediately after extraction with MasterGraft bone grafting material and 96 were placed in healed sites with no grafting material. ISQ values obtained by the Osstell ISQ System were recorded at the time of implant placement and at a subsequent follow-up appointment (T2). T2 was split into 2- to 3-month and 4- to 6-month groups depending on when their follow-up ISQ values were obtained. Data were analyzed using simple linear regression. Implants placed in healed sites had higher average ISQ values at implant placement compared with immediately placed implants; however, mean ISQ values in the 2 immediate implant groups exceeded the ISQ threshold of 65. Immediately placed implants in the 2- to 3-month and 4- to 6-month groups had average ISQ values of 65.60 and 68.65, respectively, whereas implants placed in healed sites had averages of 76.73 (2- to 3-month group) and 71.23 (4- to 6-month group). These differences were statistically significant (P < .05). At subsequent follow-up appointments, implants placed in healed sites had higher mean ISQ values. Implants in healed sites had ISQ averages of 79.58 (2- to 3-month group) and 77.31 (4- to 6-month group), whereas immediately placed implants had averages of 73.88 and 70.14. These differences were statistically significant (P < .05). Moreover, these mean ISQ values in immediate implants exceeded the ISQ threshold of 65. Although mean ISQ values of immediately placed implants are lower than those of delayed implants at implant placement and follow-up appointments, immediate implant mean ISQ values consistently remain higher than the clinically successful ISQ threshold of 65 throughout the osseointegration process. These results support the immediate placement of implants in extraction sockets under favorable conditions.

Long-term stability, survival, and tolerability of a novel osseointegrated implant for bone conduction hearing: 3-year data from a multicenter, randomized, controlled, clinical investigation.

To compare the 3-year stability, survival, and tolerability of 2 osseointegrated implants for bone conduction hearing: a wide 4.5-mm-diameter moderately roughened implant with a rounded 6-mm abutment (test) and a 3.75-mm diameter as-machined implant with a conically shaped 5.5-mm abutment (control). In this randomized, prospective, controlled, multicenter clinical study, 77 adult patients were included. Test and control implants were randomly assigned in proportions of 2:1. The implants were loaded with the sound processor from 6 weeks postimplantation. Follow-up after surgery was conducted at 10 days; at 4, 6, 8, and 12 weeks; and at 6, 12, 24, and 36 months after surgery. At every visit, implant stability quotient (ISQ) values were recorded by means of resonance frequency analysis (RFA), and skin reactions were evaluated according to Holgers' classification. Statistically significantly higher mean ISQ values were recorded for the test implant compared with the control implant at each evaluation time point. Between 2 and 3 years after surgery, ISQ values decreased but remained above baseline values. Implant survival was high for both implants: 96.2% of the test implants and 100% of the control implants survived these 3 years. Statistically significantly improved soft tissue outcomes were observed in the test implant group. This extensive long-term clinical investigation demonstrated that the test implant is more stable in terms of ISQ-values and provides high tolerability for the soft tissue. The results show that implant loading at 6 weeks is safe.

A correlation between bone (B), insertion torque (IT), and implant stability (S): BITS score

Although criteria for assessing bone quality have been reported, an overall score that correlates bone quality with the primary stability and secondary stability of implants is not yet available. The purpose of this article was to propose a scoring index that will establish a correlation among the bone density values from computed tomography, maximum insertion torque values, and resonance frequency analysis in different phases of implant treatment. In this study, 60 implant sites were evaluated to assess bone density (Hounsfield units), insertion torque values (Ncm), and primary stability and secondary stability (implant stability quotient values obtained by using resonance frequency analysis). On the basis of computed tomography data, the bone was classified as D1 to D4. The insertion torque was noted and classified into 2 groups, A and B. The implant stability quotient values obtained from resonance frequency analysis depicting primary stability and secondary stability were classified into 5 groups. The primary score noted was a result of the values obtained for the 3 parameters at the time of implant placement. The secondary score was obtained by considering the values of the bone density and resonance frequency analysis recorded at different time intervals. Bone densities of D2, D3, and D4 were noted, dividing the bone type into 3 groups. The maximum torque noted in the study was 40 Ncm. The difference between various insertion torque values and bone types was found to be statistically nonsignificant. Higher mean implant stability quotient values were obtained for primary and secondary stability for the D2 bone than for D3 and D4 bone. When analyzed according to the time of insertion, the mean values increased at second stage surgery in all bone types. The difference in mean values among all bone types was found to be statistically significant (P<.001). A comparison of primary and secondary implant stability quotient values in all bone types did not find any statistical significance (P=.780). A score was recorded at the time of implant placement and at the time of second stage surgery, and the prosthetic treatment was planned accordingly. The score highlights the importance of considering the association of bone quality, insertion torque values, and stability as denoted by implant stability quotient throughout treatment. Based on the variation in the score noted at recall visits, alterations in the treatment plan can be made with respect to the healing period and prosthetic design.

Resonance frequency analysis of osseo-integrated implants for bone conduction in a pediatric population – A novel approach for assessing stability for early loading

ObjectivesThe purpose of our study was to directly measure the stability of a bone anchored hearing device (BAHD) abutment using resonance frequency analysis (RFA) in a pediatric population. RFA was used to guide early loading of the abutment following single stage surgery. MethodsThe principle behind RFA is to obtain a numerical value relating to stability. A Smartpeg (1cm commercially manufactured attachment) is screwed onto the abutment – its resonance in a magnetic field is measured with an Osstell recording device. The degree of movement (vibration) is inversely proportional to the stability of the abutment and a numerical figure, the Implant Stability Quotient (ISQ), is derived. RFA measurements were obtained at surgery, 4 weeks and 16 weeks post implant surgery. Patients were fitted with the new CochlearTM Baha® BI300 series implant using a one-stage procedure and based on RFA stability measures, loading of the sound processor occurred any time from 1 week after implant surgery if the RFA measure was 60 units or over. ResultsTwenty two consecutive patients were recruited. Eight patients had bilateral BAHD's fitted giving a total of 30 implants. The age range was 2–16 years with an average age of 9 years at time of fitting. The time interval from surgery to loading the processor ranged from 1 to 16 weeks, with an average time of 6 weeks. The mean ISQ value at time of surgery was 61.29 (95% CI=2.03), at 4 weeks was 61.92 (95% CI=2.97) and at 16 weeks was 63.45 (95% CI=3.18). ConclusionsOur study shows we have been able to operate a successful program of earlier BAHD loading using single stage surgery in children. This is supported by favorable RFA measures of implant stability with average ISQ values of over 60 units.

Assessment of primary implant stability of self-tapping implants using the resonance frequency analysis

The objective of this study was to determine the influence of implant surface modification and implant length on primary implant stability using resonance frequency analysis (RFA). Twenty-seven patients with bilateral free end mandible were treated with 162 dental self-tapping implants (72 implants with sandblasted and acid-etched surface (SLA) with 8 and 10 mm length, respectively; 90 implants with chemically modified SLA surface (modSLA) and a length of 8 mm). Implant stability quotient (ISQ) values were determined and were compared in between the implant types using statistical analysis ( t -test). Mean ISQ value for all 162 implants was 79.09 (5.97). Statistically significant differences were noted between mean ISQ value of SLA and modSLA implants (76.92 vs. 80.80). Also significantly lower mean ISQ values have been recorded for 8 mm length implants compared to 10 mm length implants in the SLA group (74.15 vs. 79.57). All ISQ values indicate the high primary stability for tapper implants inserted in the posterior part of the mandible. Self-tapping implant design provides sufficient initial stability even for implants with nonstandard length. Further investigations are necessary to define the influence of surface chemical modification on primary implant stability.

Immediate Loading With LASER-Treated Surface Implant

The chemical, physical, and morphologic characteristics of the implant surface play a fundamental role during the osteointegration process. Implant design is of paramount importance in determining implant primary stability and implant ability to sustain loading during and after osteointegration. LASER treatment of the surface allows defining the precise parameters of roughness to obtain a regular and repeatable surface in total absence of contamination. The aim of this study was to analyze the behavior of implant stability of LASER-treated surface implants by repeated resonance frequency analysis (RFA) measurements during 2 years in patients with complete upper maxilla edentulism subject to an immediate-loading protocol. Ten patients were included, and each treated with the insertion of 6 or 8 LASER surface implants according to the individual surgical-prosthetic planning. During the bone drilling and implant insertion, torque values were monitored with a specific handpiece and software. All implants were loaded within 24 hours from the insertion with the application of a temporary full-arch prosthesis. Subsequent follow-up has been done at 24 months from the loading with radiographic controls (OPT) and RFA measurement on all implants at time of implant insertion and at 1, 3, 6, 12, and 24 months from loading. Resonance frequency analyses at 3 and 6 months from the implant loading have shown a rapid increment of implant stability quotient (ISQ) values in the first phases of bone remodeling, subsequent to the peri-implant bone remodeling. The paired comparisons between mean ISQ values by patient showed a statistically significant decrease in primary stability from baseline up to 1 month (P = 0.0039). Subsequent measurements revealed a statistically significant increase in implant stability from 1 up to 3 months (P = 0.0156), from 3 up to 6 months (P = 0.0020), from 6 up to 12 months (P = 0.020), and 12 up to 24 months (P = 0.0391). Resonance frequency analysis of the LASER-treated surface implants showed good ISQ values at all time point measurements. These results are consistent with data from literature on the analysis of RFA in protocols of immediate loading at the upper maxilla.

Bone-Anchored Hearing Implant Loading at 3 Weeks

To clinically evaluate the performance of a titanium percutaneous bone-anchored hearing implant (BAHI) using a 3-week healing period. Short-term implant survival, stability changes, and skin reactions are evaluated from the initial implantation to 6 months postimplantation. Thirty patients eligible for a BAHI were included in an open, prospective clinical investigation. Implant stability quotient (ISQ) values were recorded using resonance frequency analysis (RFA) at the time of implantation and at 10 days; at 3, 6, and 12 weeks; and at 6 months after placement of the implant. Sound processor fitting was performed 3 weeks after implantation. Skin reactions were evaluated according to the Holgers classification. One implant was lost 3 days after implantation because of poor bone quality. No implant loss occurred in the remaining 29 patients (96.7%). The mean ISQ value at the time of implantation was 67.1 (range, 44-71). Compared with baseline, there was a significant dip of -2.2 ISQ units at 10 days (mean, 65.7; p = 0.0093). There was a positive change in mean ISQ compared with baseline over the subsequent visits. No reduction in mean ISQ values was observed after implant loading. Skin reactions were observed incidentally (mean over all visits, 9.7%) and were generally mild (Holgers Grade 1; mean 9.0%). An adverse skin reaction (Holgers Grade 2) was observed only once (mean, 0.7%). The current study suggests that loading the implant and 6-mm abutment with the sound processor at 3 weeks is safe. The stability of the implant as measured by ISQ values had reached its baseline value within 3 weeks after implantation. The degree of stability was not affected by implant loading. Only mild skin reactions were observed incidentally. This study supports the use of early loading at 3 weeks as current practice in healthy adults with good bone quality; thus, these adults can benefit from the rehabilitation of their hearing at an earlier stage.