Relationship between implant stability measurements obtained by insertion torque and resonance frequency analysis: A systematic review

Implant Stability After Graftless Motor-Driven Crestal Sinus Elevation: A Cohort Study

Graftless motor-driven crestal sinus elevation may be a preferable alternative to conventional methods due to the reduction of postsurgical complications and lower cost. This prospective cohort study evaluated the stability of implants installed using this technique. Twenty-nine Straumann BLT (bone level tapered) implants in 29 patients were included in the sample. Average implant stability quotients (ISQ) were measured immediately after surgery (mean: 73.5 ± 9.2) and after a period of healing (mean: 77.1 ± 4.5) using resonance frequency analysis (RFA). There was a significant increase in implant stability after healing (P = .035). The healing duration did not significantly influence how implant stability increased (P =.373). The mean ISQ after healing was significantly higher than the clinically acceptable stability value of 65 ISQ (P < .001). Implant length and width were not significantly correlated with ISQ increase (P = .764 and P = .085, respectively). In addition, there were no significant differences in average ISQ values measured immediately postsurgery (at baseline) or after healing between implants with and without registered perforations during surgery (P = .118 and P = .366, respectively). The posthealing stability of 4 implants that did not achieve primary stability was not significantly less stable after the healing period than those that had achieved primary stability (P = .086). Moreover, the level of insertion torque significantly impacted implant stability immediately postsurgery (P < .001), but the ISQ values measured after healing were not significantly different based on the initial insertion torque values (P = .131). This study suggests that implants installed using graftless motor-driven crestal sinus elevation may achieve clinically acceptable stability as measured by RFA.

Fatigue lifetime of reduced-diameter implants placed in different bone models

OBJECTIVES

This study assessed the fatigue lifetime of reduced-diameter implants placed in either bovine rib or polymer-based bone model.

METHODS

Bovine ribs were classified according to the criteria proposed by Lekholm and Zarb and were analyzed for bone fraction. Fourteen dental implants (3.25 mm in diameter × 15 mm in length) were placed in bovine ribs used as a bone model. They were subjected to resonance frequency analysis. Stainless steel loading hemisphere caps were bonded on the abutments position at 30-degree angle and with a moment arm of 11 mm. Accelerated life testing using the step-stress method was conducted at 2 Hz with a stress ratio of 0.1 until fracture on a servo-hydraulic load frames machine (MTS). Results were compared with those of a previous study wherein implants were placed in a polymer-based bone model. Fatigue lifetime statistics (characteristic lifetime and Weibull modulus) of physical specimens were estimated in a reliability analysis software (ALTA PRO). Fractured specimens were examined under an electron scanning microscope to determine the failure mode.

RESULT

The implants exhibited high stability quotient values (75.07 ± 3.81). Implants placed in bovine ribs showed better data dispersion and longer fatigue lifetime than those placed in polymer-based bone models, with no significant difference between groups. All fractures occurred in the implant body near the bone level and were indicative of fatigue fractures.

SIGNIFICANCE

Bovine ribs appear to be a more suitable material for accelerated life testing than the polymer-based material because of better data dispersion.

Influence on marginal bone levels at implants equipped with blades aiming to control the lateral pressure on the cortical bone. An experimental study in dogs

BACKGROUND

To avoid cortical compression, several implant systems have included in the protocol dedicated drills aimed at widening the cortical region of osteotomy. However, the manual execution of this operation does not guarantee the necessary precision. Hence, the present study aimed to determine the optimal size of the recipient site at the level of the alveolar crest in relation to the size of the coronal region of the implant to achieve the best healing result.

MATERIALS AND METHODS

Blades of different diameters were incorporated into the coronal part of the implant to prepare the cortical region of the mandibular alveolar bone crest in different dimensions in relation to the collar of the implant. The differences in diameter of the blades in relation to the collar of the implant were as follows: one control group, -175 μm, and three test groups, 0 μm, + 50 μm, or + 200 μm.

RESULTS

The marginal bone loss (MBL) at the buccal aspect was 0.7 mm, 0.5 mm, 0.2 mm, and 0.7 mm in the - 175 μm, 0.0 μm, + 50 μm, + 200 μm groups, respectively. The differences were statistically significant between group + 50 μm and control group - 175 μm (p = 0.019), and between + 50 μm and + 200 μm (p < 0.01) groups. The level of osseointegration at the buccal aspect was more coronally located in the test groups than in the control group, whereas the bone-to-implant contact percentage was higher in the + 50 μm and + 200 μm groups. However, these differences were not statistically significant.

CONCLUSIONS

The lowest bone crest resorption and highest levels of osseointegration were observed in the 0.0 μm and + 50 μm groups. The cortical region where the blades had performed their cutting action showed regular healing with perfect hard and soft tissues sealing in all the groups. Cortical blades gathered bone particles, particularly in the + 200 μm group, which were incorporated into the newly formed bone. The results from the present experiment provide support to the use of blades that produce a marginal gap of 50 μm after implant insertion.

Primary stability and osseointegration comparing a novel tapered design tissue-level implant with a parallel design tissue-level implant. An experimental in vivo study

OBJECTIVES

The aim of the present study was to compare a novel tapered, double-threaded self-tapping tissue-Level design implant (TLC) to a well-established parallel walled tissue-level (TL) implant in terms of primary and secondary stability over time.

MATERIALS AND METHODS

Test TLC (n = 10/per timepoint) and control TL (n = 10/per timepoint) implants were placed in the mandible of minipigs and left for submerged healing for 3, 6, and 12 weeks. Maximum insertion torque and implant stability quotient (ISQ) were measured for each implant at placement. Osseointegration and cortical bone maintenance were histologically evaluated by measuring total bone-to-implant contact (BIC) and first bone-to-implant contact (fBIC).

RESULTS

A significantly higher maximum insertion torque was measured for the test implant TLC compared to the control TL implant (57.83 ± 24.73 Ncm and 22.62 ± 23.16 Ncm, respectively; p < .001). The mean ISQ values were comparable between the two implant types (75.00 ± 6.70 for TL compared to 75.40 ± 3.20 for TLC, p = .988). BIC was comparable between both implant types at each of the evaluated time points. The fBIC was found to be significantly more coronal at 12 weeks for the TLC implant compared to the TL implant (0.31 ± 0.83 mm for TLC compared to -0.22 ± 0.85 for TL, p = .027).

CONCLUSION

The novel tapered tissue level design implant showed improved primary stability and an overall improved crestal bone height maintenance compared to the parallel walled design at 12 weeks.

Correlation between Implant Surface Roughness and Implant Stability: A Systematic Review

The aim of this study was to find in the literature data on the relationship between implant surface roughness and implant stability achieved, from the time of placement to three months afterward, to help us to know what type of surface roughness is more favorable to guarantee implant stability and osseointegration. A systematic review was conducted in accordance with the PRISMA 2020 (Preferred Reporting Items for Systematic Review and Meta-analysis) statement, and the protocol was registered on the Open Science Framework. The specific inclusion and exclusion criteria were selected using the PICOS framework. The databases Medline (PubMed), Scopus, the Web of Science and The Cochrane Library were searched up to October 2023. The selection of studies and data extraction were conducted by two independent reviewers. The review included a total of 11 studies. A total of 1331 dental implant placements were identified. Two of the eleven selected studies were on humans in vivo, eight were on animals in vivo, and one was on animals in vitro. A statistically significant correlation between surface roughness and implant stability as measured by resonance frequency analysis (RFA) was not identified in ten of the eleven selected studies. It appears that there is no correlation between primary stability and the degree of implant roughness. However, there appears to be a correlation between the roughness of the implant and the degree of osseointegration, as indicated by bone-implant contact values. This correlation is more closely related to secondary stability. The great methodological variability makes it difficult to compare data and draw conclusions, so it would be desirable to agree on a common methodology to help draw appropriate conclusions from published studies.

Primary stability evaluation of different morse cone implants in low-density artificial bone blocks: A comparison between high-and low-speed drilling

This study aimed to evaluate various biomechanical parameters associated with the primary stability of Maestro and Due Cone implants placed in low-density artificial bones, prepared using high-speed drilling with irrigation and low-speed drilling without irrigation. The insertion torque (IT), removal torque (RT), and implant stability quotient (ISQ) values were recorded for Maestro and Due Cone implants placed in low-density polyurethane blocks (10 and 20 pounds per cubic foot (PCF) with and without a cortical layer) prepared using high-speed and low-speed with or without irrigation using a saline solution, respectively. A three-way ANOVA model and Tukey's post-hoc test were conducted, presenting data as means and standard deviations. P-values equal to or less than 0.05 were considered statistically significant. No statistically significant differences in IT, RT, and ISQ between drilling speeds were observed. However, Maestro implants exhibited lower IT and RT values after high- and low-speed drilling across almost all polyurethane blocks, significantly evident in the 20 PCF density block for IT and in the 20 PCF density block with the cortical layer for the RT with low-speed drilling (IT: 47.33 ± 10.02 Ncm and 16.00 ± 12.49 Ncm for Due Cone and Maestro implants, respectively, with p < 0.01; RT: 44.67 ± 22.81 Ncm and 20.01 ± 4.36 Ncm for Due Cone and Maestro implants, respectively, with p < 0.05) and among the same implant types inserted in different bone densities. Additionally, the study found that for all bone densities and drilling speeds, both implants registered ISQ values exceeding 60, except for the lowest-density polyurethane block. Overall, it can be inferred that low-speed drilling without irrigation achieved biomechanical parameters similar to conventional drilling with both implant types, even with lower IT values in the case of Maestro implants. These findings suggest a promising potential use of low-speed drilling without irrigation in specific clinical scenarios, particularly when focusing on preparation depth or when ensuring proper irrigation is challenging.

Immediate versus early loading of immediately placed bone-level tapered dental implants with hydrophilic surface in full arch maxillary rehabilitation: A pilot randomized clinical trial with 2-year follow-up

This study aimed to compare implant stabilities between the immediate and early loaded, immediately placed bone-level tapered dental implants in the maxilla and to evaluate marginal bone loss (MBL), oral health-related quality of life (OHRQoL), and patient satisfaction at a 2-year follow-up. A pilot, prospective, randomized, controlled clinical trial was conducted on 24 maxillary failing dentition patients. The bone-level tapered implants of 12 patients were immediately loaded with temporary restorations, while the other 12 patients did not receive any kind of temporization. Implant-supported screw-retained complete porcelain-fused-to-metal prostheses were delivered to all patients in the seventh postoperative week. The insertion torque values of implants assigned to the immediate and early loading groups were 33.0 ± 4.87 and 29.26 ± 8.31 Ncm, respectively. The dynamics of implant stability changes from implant placement up to a 2-year follow-up were similar for both groups (Penguin®, p = 0.268; Ostell®, p = 0.552), while the MBL was at submillimeter level. The cumulative implant survival rate was 91.80% for immediately loaded implants and 97.22% for early loaded implants, without significant difference (p = 0.162). The total score on the Oral Health Impact Profile questionnaire significantly decreased over time in both groups, indicating improvement in OHRQoL (p < 0.001), and the high level of patient satisfaction remained after 2 years of function regardless of a loading protocol. Both loading protocols, immediate and early, of six immediately placed bone-level tapered dental implants are an adequate treatment choice for fixed rehabilitation of the maxillary failing dentition.

Clinical evaluation of implants placed within or beyond the boundaries of the alveolar ridge preservation: a retrospective case series with 10 weeks of observations in 28 patients

PURPOSE

This study investigated the effect of implant vertical positioning within alveolar ridge preservation (ARP) sites on implant stability quotient (ISQ) values, which were measured 10 weeks post-implantation.

METHODS

Patients who underwent ARP using collagenized deproteinized bovine bone mineral, followed by implant placement in the posterior area, were divided into 2 groups: the within-ARP group and the beyond-ARP group. In the within-ARP group, osteotomy and implant placement occurred within the ARP boundary. In contrast, in the beyond-ARP group, these procedures were performed beyond the ARP boundary, incorporating 3 mm of pristine bone at the implant's apex. Bone quality was assessed by tactile sense, and both insertion torque during implant surgery and ISQ values at 10 weeks post-implant surgery were measured. Multiple linear regression analysis and Pearson correlation analysis were used to explore the relationship between insertion torque and ISQ values.

RESULTS

In total, 30 ARP sites in 28 patients were analyzed. There was no significant difference in bone quality, as determined by tactile sense, between the within-ARP and beyond-ARP groups. At the time of implant placement, the beyond-ARP group exhibited a higher insertion torque (33.33±13.39 Ncm) compared to the within-ARP group (17.08±11.17 Ncm). However, the ISQ values were similar between the 2 groups 10 weeks after implant placement. A positive correlation between insertion torque and ISQ values was confirmed at 10 weeks post-implant.

CONCLUSIONS

The engagement of pristine bone may facilitate high insertion torque during the placement of implants in ARP sites. Nevertheless, by 10 weeks post-implantation, the ISQ values were found to be comparable, irrespective of the implant's position.

Effects of dental implant diameter and tapered body design on stress distribution in rigid polyurethane foam during insertion

Anchorage, evaluated by the maximum insertion torque (IT), refers to mechanical engagement between dental implant and host bone at the time of insertion without external loads. Sufficient anchorage has been highly recommended in the clinic. In several studies, the effects of implant diameter and taper body design under external loading have been evaluated after insertion; however, there are few studies, in which their effects on stress distribution during insertion have been investigated to understand establishment of anchorage. Therefore, the objective of this study was to investigate the effects of dental implant diameter and tapered body design on anchorage combining experiments, analytical modeling, and finite element analysis (FEA). Two implant designs (parallel-walled and tapered) with two implant diameters were inserted into rigid polyurethane (PU) foam with corresponding straight drill protocols. The IT was fit to the analytical model (R2 = 0.88-1.0). The insertion process was modeled using explicit FEA. For parallel-walled implants, normalized IT and final FEA contact ratio were not related to the implant diameter while the implant diameter affected normalized IT (R2 = 0.90, p < 0.05, β1 = 0.20 and β2 = 0.93, standardized regression coefficients for implant diameter and taper body design) and final FEA contact ratio of tapered implants. The taper design distributed the PU foam stress further away from the thread compared to parallel-walled implants, which demonstrated compression in PU foam established by the tapered body during insertion.

Correlation Between Acquisition of Dental Implant Stability and Hounsfield Units at Dental Implant Placement

Alveolar bone quality at the implantation site affects the initial stability of dental implant treatment. However, the relationship between bone quality and osseointegration has yet to be evaluated. Herein, we aimed to investigate the effect of bone quality on dental implant stability in osseointegration formation changes. Patients underwent computed tomography imaging before dental implantation at the posterior. Hounsfield units were measured at the platform, middle, and tip sites. Implant stability was measured using resonance frequency analysis immediately and at 3 months postoperatively, in which the difference in implant stability quotients (ISQ) was defined as the change between primary and secondary fixation. In multiple regression analysis, the dependent variable was the change between the immediate and secondary fixations. We included 81 implants that conformed to the criteria. Primary fixation yielded the following results: R2 = 0.117, F = 2.529, and P = .047. The difference between the maxilla and mandible of the implantation site (P = .02) and the platform-site Hounsfield units (P = .019) were identified as significant factors. The following results were obtained regarding the change between the immediate and secondary fixation: R2 = 0.714, F = 40.964, and P < .001. The difference between diameter (P = .008) and the immediate ISQ (P < .001) were identified as significant factors. Overall, the bone quality of the implantation site affected initial fixation; however, it had limited effect on secondary fixation. Our findings clarified the period where bone quality affects dental implant treatment and is expected to advance dental implant treatment.

Influence of implant length and insertion depth on primary stability of short dental implants: An in vitro study of a novel mandibular artificial bone model

Background/purpose

Dental implants are a mainstream solution for missing teeth. For the improvement of dental implant surface treatment and design, short dental implants have become an alternative to various complex bone augmentation procedures, especially those performed at the posterior region of both the maxilla and mandible. The objective of this study was to evaluate the effect of various insertion methods on the primary stability of short dental implants.

Materials and methods

Commercial dental implants were inserted into artificial mandibular bone specimens using various insertion methods (equicrestal position, subcrestal position 1.5 mm, and lateral cortical anchorage) in accordance with an implant surgical guide. Insertion torque value (ITV) curves were recorded while implant procedures were performed. Both maximum ITVs (MITVs) and final ITVs (FITVs) were evaluated. Subsequently, Periotest values (PTVs) and implant stability quotients (ISQs) were measured for all specimens. A Kruskal-Wallis test was conducted to analyze the results for four primary stability parameters, and the Dunn test was used for a post hoc pairwise comparison when a difference was identified.

Results

For all groups, their mean MITVs ranged from 33.6 to 59.4 N cm, whereas their mean FITVs ranged from 17.5 to 43.5 N cm. Insertion torque value, ISQ, and PTV decreased significantly when implants were inserted into subcrestal positions. When implants were inserted in the lateral bicortical position, the four aforementioned parameters yielded greater values.

Conclusion

When 6-mm short implants were inserted in a lateral cortical anchorage position, high primary stability was yielded.

Significance of bone morphology and quality on the primary stability of orthodontic mini-implants: in vitro comparison between human bone substitute and artificial bone

AIM

This study evaluated artificial bone models against a human bone substitute to assess the primary stability of orthodontic mini-implants (OMIs) at varying implant sites with different morphologies and qualities.

MATERIALS AND METHODS

A total of 1200 OMI placements of four types were inserted into four artificial bone models of different density (D1, D2, D3, D4) and into a human bone substitute (HB). The implants varied in diameter (2.0 and 2.3 mm) and length (9 and 11 mm). Each specimen had four implant sites: no defect, one-wall defect, three-wall defect, and circular defect. The implant stability quotient (ISQ) values were measured using resonance frequency analysis (RFA) and insertion placement torque values (IPT) were assessed for primary stability. Correlation analysis was performed to evaluate the different models.

RESULTS

The highest IPT value was registered for the 2.0 mm × 11 mm implant inserted into D1 with no defect (37.53 ± 3.02 Ncm). The lowest ISQ value was measured for the 2.3 mm × 9 mm OMI inserted into D3 with a circular defect (12.33 ± 5.88) and the highest for the 2.3 mm × 9 mm implant inserted into HB with no defect (63.23 ± 2.57). A strong correlation (r = 0.64) for IPT values and a very strong correlation (r = 0.8) for ISQ values was found between D2 and HB.

CONCLUSION

Bone defects and bone quality affected the primary stability of implants in terms of ISQ and IPT values. Results for bone model D2 correlated very well with the HB substitution material.

Influence of Multiple Sterilization on Performance of Titanium Pegs When Measuring Implant Stability With Resonance Frequency Analyses

This in vitro study was conducted to investigate the repeatability of the implant stability quotients (ISQ) measured with multipegs after numerous sterilizations and to detect the exact time when the readings start to deviate. Multipegs were sterilized with 3 different methods (autoclaved, autoclaved + ultrasonic cleaner, chemical disinfection + autoclaved) and grouped according to the method applied. All specimens were put into the autoclave with sealed packages every time they were sterilized. Each specimen was sterilized 50 times according to the technique described in its group after an ISQ measurement was performed. Results of the 2-way analysis of variance showed that neither the sterilization method nor the cycles, nor their interaction, were statistically significant. A multipeg may be reused multiple times after sterilization procedures and may be more cost-effective than a disposable smartpeg for checking implant stability after confirming these results in further investigations.

Resonance Frequency Analysis Mapping During Implant Healing Using a Nanostructured Hydroxyapatite Surface

Aim

Stability measured by resonance frequency analysis (RFA) is an important factor to be considered in the success of dental implant treatments, which can be evaluated from the implant stability quotient (ISQ). The aim of the present case series was to map the RFA during healing of implants with nanostructured hydroxyapatite surface to describe the behavior of ISQ values related to individual factors.

Materials and Methods

Twenty-three implants were placed in eight patients by conventional surgical protocol, and ISQ values were monitored from the day of implant placement until week 20. To obtain the ISQ values, an Osstell device was used and the placed implants were grouped in proportional amounts to describe the ISQ behavior considering the length (≤10 or >10 mm), the diameter (3.5 or 4.3 mm), the insertion torque (<40 N-cm or ≥40 N-cm), and the placement area (maxilla or mandible).

Results

All the implants assessed decreased their values in the first 3 weeks after placement. Subsequently, the ISQ values increased by amounts similar to those obtained at the time of the placement and even more. Implants with length >10 mm, diameter 4.3 mm, and insertion torque ≥40 N-cm showed the highest ISQ values.

Conclusions

A decrease in the ISQ values of dental implants with nanostructured hydroxyapatite surface was evidenced between weeks 2 and 3 considering length, diameter, insertion torque, and maxillary or mandibular placement site.

A Comparison of Conical and Cylindrical Implants Inserted in an In Vitro Post-Extraction Model Using Low-Density Polyurethane Foam Blocks

Combining tooth extraction and implant placement reduces the number of surgical procedures that a patient must undergo. Thus, the present study aimed to compare the stability of two types of conical implants (TAC and INTRALOCK) and another cylindrical one (CYROTH), inserted with a range of angulation of 15-20 degrees in low-density polyurethane blocks (10 and 20 pounds per cubic foot, PCF) with or without a cortical lamina (30 PCF), which potentially mimicked the post-extraction in vivo condition. For this purpose, a total of 120 polyurethane sites were prepared (10 for each implant and condition) and the Insertion Torque (IT), Removal Torque (RT), and Resonance Frequency Analysis (RFA) were measured, following a Three-Way analysis of variance followed by Tukey's post hoc test for the statistical analysis of data. The IT and RT values registered for all implant types were directly proportional to the polyurethane density. The highest IT was registered by INTRALOCK implants in the highest-density block (32.44 ± 3.28 Ncm). In contrast, the highest RFA, a well-known index of Implant Stability Quotient (ISQ), was shown by TAC implants in all clinical situations (up to 63 ISQ in the 20 PCF block without the cortical sheet), especially in lower-density blocks. Although more pre-clinical and clinical studies are required, these results show a better primary stability of TAC conical implants in all tested densities of this post-extraction model, with a higher ISQ, despite their IT.

Reliability of implant stability measuring devices depending on various clinical conditions: an in vitro study

PURPOSE

The aim of this study was to evaluate the reliability of implant stability measuring devices depending on the location of the implant and the position of the patient.

MATERIALS AND METHODS

Six implants were installed in different dentate sextants of six artificial bone models. Implant stability was measured in three conditions of the bone model (without mounting on a phantom head, mounted on a phantom head in supine position, and mounted on a phantom head in upright position). A resonance frequency analysis device (Osstell) and two damping capacity analysis devices (Periotest and Anycheck) were used to measure implant stability. The values measured outside the phantom head were treated as controls, and the values inside the phantom head were compared using an independent t-test.

RESULTS

Osstell showed different results in two of the six divisions in both the supine and upright positions compared to outside of the mouth (P < .05). Periotest showed different results in all six parts in the supine position and in five parts in the upright position compared to outside of the mouth (P < .05). While Anycheck showed different results in five areas in the supine position compared to outside of the mouth, it showed different results in only one area in the upright position (P < .05).

CONCLUSION

In the difficult implant position for the operator to access, the implant stability measuring devices show less reliability. The accessibility of implant is greatly affected in the order of Osstell, Anycheck, and Periotest.

Influence of design implant and apical depth in post-extraction sockets: an in vitro simulated study

BACKGROUND

Implant design and apical stability are principal parameters involved in achieving successful primary stability. Using polyurethane models to simulate post-extraction sockets, we investigated the effects of using differing blade designs on the primary stability of tapered implants and the impact of apical depth.

METHOD

Six polyurethane blocks were used to simulate post-extraction pockets. One of the implants presented self-tapping blades (Group A), while the other (Group B) did not. Seventy-two implants were placed at 3 different depths (5 mm, 7 mm, and 9 mm), and a torque wrench was used to measure the stability of the implants.

RESULTS

When evaluating the implants (placed at 5 mm, 7 mm, and 9 mm apical to the socket), we observed that the torque of the Group B implants was higher than that of Group A implants (P < 0.01). At the 9-mm depth, there was no difference between the groups (Drive GM 34.92 Ncm and Helix GM 32.33 Ncm) (P > 0.001), and considering the same implant groups, those placed at 7-mm and 9-mm depths presented higher torques (p < 0.01) than those placed at 5-mm (p > 0.01).

CONCLUSION

Considering both groups, we concluded that an insertion depth of greater than 7 mm is needed for initial stability, and in situations involving reduced supportive bone tissue or low bone density, a non-self-tapping thread design improves implant stability.

Implant rehabilitation of a posterior maxilla with 4-mm long implants splinted to a 10-mm long implant in a patient with osteopenia taking antiresorptive drugs: A 5-year follow-up case report

The report describes the rehabilitation of a maxillary arch with limited bone volume in a 67-year-old female taking antiresorptives due to osteopenia. One 10-mm and two extra-short 4-mm implants were inserted, and implant-supported splinted crowns were fabricated. The 5-year follow-up showed stable bone levels, despite poor initial stability (ISQ: 14-51).

Associations between cortical bone-to-implant contact and microstructure derived from CBCT and implant primary stability

OBJECTIVES

To evaluate the associations between the cortical bone-to-implant contact (CBIC), bone microstructure derived from cone-beam computed tomography (CBCT), and the primary stability of the implant.

MATERIALS AND METHODS

Twenty-two patients with 65 implants were enrolled in this study. The peak insertion torque values (ITVs) were measured during implant insertion, and the implant stability quotient (ISQ) values were measured immediately after implant placement and 3 months after surgery. The profiles of the peri-implant bone structure were outlined using the volumetric reconstruction of the CBCTs and superimposition of the virtual models, and the features of CBIC and bone microstructure parameters were measured. The linear mixed effects model and generalized estimating equation were used to explore the predictors for implant primary stability.

RESULTS

The average ITV, baseline, and secondary ISQ values were 31.44 ± 6.54 N·cm, 73.34 ± 7.39, and 80.32 ± 4.58, respectively. Statistically significant correlations were found between ITV and surface area of CBIC (r = .340, p = .006), bone volume fraction (r = .294, p = .017), and bone surface fraction (r = -.278, p = .039). Implants with buccolingual CBIC had a higher ITV than implants without CBIC (p = .016). None of the parameters were associated with baseline and secondary ISQ values in generalized estimating equation analysis (all p > .05).

CONCLUSIONS

Within the limitations of the study, preoperative CBCT measurements might enable the prediction of ITV and therefore of implant primary stability values.

In vivo osseointegration evaluation of implants coated with nanostructured hydroxyapatite in low density bone

OBJECTIVE

This in vivo study, aimed to biomechanically, histomorphometrically and histologically evaluate an implant surface coated with nanostructured hydroxyapatite using the wet chemical process (biomimetic deposition of calcium phosphate coating) when compared to a dual acid-etching surface.

MATERIAL AND METHODS

Ten sheep (2-4 years old) received 20 implants, 10 with nanostructured hydroxyapatite coating (HAnano), and 10 with dual acid-etching surface (DAA). The surfaces were characterized with scanning electron microscopy and energy dispersive spectroscopy; insertion torque values and resonance frequency analysis were measured to evaluate the primary stability of the implants. Bone-implant contact (BIC) and bone area fraction occupancy (BAFo) were evaluated 14 and 28 days after implant installation.

RESULTS

The HAnano and DAA groups showed no significant difference in insertion torque and resonance frequency analysis. The BIC and BAFo values increased significantly (p<0.05) over the experimental periods in both groups. This event was also observed in BIC value of HAnano group. The HAnano surface showed superior results compared to DAA after 28 days (BAFo, p = 0.007; BIC, p = 0.01).

CONCLUSION

The results suggest that the HAnano surface favors bone formation when compared to the DAA surface after 28 days in low-density bone in sheep.

Surface Modifications of Commercial Dental Implant Systems: An Overview

The aim of this review was to perform a comprehensive overview of evidence pertaining to the influence of various surface modifications on the surface roughness, bone implant contact, and the success and complication rates of the implants. Modified sandblasted, large-grit, acid-etched (SLA) implants (SLActive implants) have a higher implant stability quotient compared with conventional SLA implants. Also, when compared between the implant surfaces from various manufacturers, Biomet 3i Nanotite implants were shown to have a relatively higher implant stability quotient compared to Straumann implants as well as the Biomet Osseotite implants. Only one study reports the insertion torque values as obtained by the various implant surfaces, with the findings being statistically similar for all the types, and a higher mean value for Biomet 3i Nanotite implants. Among SLA and SLActive surfaces, the latter was found to have a lower marginal bone loss, and among Astratech implants, the marginal bone loss levels were similar for Osseospeed and Tioblast surfaces. When Osseospeed, TiUnite and SLActive surfaces were compared, Osseospeed was found to have the minimum bone loss while TiUnite was found to have the highest. The bone implant contact percentages are similar and satisfactory for most of the implant surface modifications that are available currently. Upon assessing the recent literature on the survival rates for implants with various surface modifications, it was found that among Nobel Biocare implants, the survival rate was higher for TiUnite implants, compared with the turned surfaces. Surprisingly, among the Straumann implant surfaces, the survival rates were found to be higher for the SLA implants when compared to the modified SLA implants. Only one of the included studies evaluated the survival rate for Astratech implant surfaces and found a 100% survival rate for both the Osseospeed and Tioblast surface implants. Therefore, major advancements have been made in developing novel surfaces of dental implants. The numerous innovations set the stage for rehabilitating patients with high success and predictable survival rates even in challenging conditions.

Randomized Clinical Trial Comparing Insertion Torque and Implant Stability of Two Different Implant Macrogeometries in the Initial Periods of Osseointegration

Objectives: The present study compared two implants with different macrogeometries placed in healed alveolar sites, evaluating the insertion torque (ITV) and implant stability quotient (ISQ) values at three different periods. Methods: Seventy patients with a total of 100 dental implants were allocated into two groups (n = 50 per group): DuoCone implants (DC group) that included 28 implants in the maxilla and 22 in the mandible, and Maestro implants (MAE group) that included 26 in the maxilla and 24 in the mandible. The ITV was measured during the implant placement, and the ISQ values were measured immediately at implant placement (baseline) and after 30 and 45 days. Results: The mean and standard deviations of the ITV were statistically significant (p < 0.0001), 56.4 ± 6.41 Ncm for the DC group and 29.3 ± 9.65 Ncm for the MAE group. In the DC group, the ISQs ranged between 61.1 ± 3.78 and 69.8 ± 3.86, while the MAE group presented similar values compared with the other group, ranging between 61.9 ± 3.92 and 72.1 ± 2.37. Conclusions: The value of implant insertion torque did not influence the ISQ values measured immediately after implant placement. However, the ITV influenced the ISQ values measured in the two initial periods of osseointegration, with implants installed with lower torques presenting higher ISQ values.

Can the Immediate Implantation With Immediate Loading Achieve an Acceptable Esthetic Outcome? A Prospective Observational Clinical Study

The trending protocol in implantology aims at integrating the esthetic on par with function while reducing discomfort and treatment time with optimal results. The purpose of this study was to evaluate the pink esthetic score in sites treated by graftless instant implantation that was boosted by instant provisionalization with a 2 to 3 mm jumping distance. Thirty-five implants were inserted in the extraction sockets of teeth of 29 healthy qualified patients (22 females and 7 males) with an age range of 23 to 60 years [mean±SD age 41.11±9.9 y). Preoperative assessment was complemented clinically and radiographically for each patient. The used system was Medentika dental implant (Germany). Osstell implant stability quotient was used to measure implant stability at the time of surgery (baseline) and at 16 weeks. Four implants in 3 patients failed. The implant survival rate was 88.6%. The protocol of this study produced a significant decrease in the jumping distance which is 2 to 3 mm at cone-beam computed tomography evaluation with satisfactory esthetic outcomes clinically. Further comparative studies with long-term and larger samples are needed to confirm the conclusion of this study.

Validation of an implant stability measurement device using the percussion response: a clinical research study

Background

Several devices have been developed to measure implant-bone stability as an indicator of successful implant treatment; these include Osstell®, which measures the implant stability quotient (ISQ), and the more recent AnyCheck®, which relies on percussion for the implant stability test (IST). These devices make it possible to measure implant stability. However, no studies have compared the performance of AnyCheck® and Osstell® (i.e., IST and ISQ values) in clinical practice. Therefore, this study aimed to determine the correlation between primary and secondary implant stability using the Osstell® and AnyCheck® devices.

Methods

Ten patients (7 women; age [mean ± standard deviation]: 49.1 ± 13.3 years) with partially edentulous jaws who received a total of 15 implants were included. IST (AnyCheck®) and ISQ (Osstell®) values were measured immediately after implantation and at 1, 2, 3, 4, and 6 weeks post-implantation. Each measurement was performed three times, and the average value was used as the result. The correlation between measurements obtained using the two devices was determined using Spearman's rank correlation coefficient.

Results

The IST values ranged from 79.1 ± 2.87 to 82.4 ± 2.65. The ISQ values ranged from 76.0 ± 2.8 to 80.2 ± 2.35. Spearman's rank correlation coefficient was r = 0.64 immediately after implantation, r = 0.29 at 1 week, r = 0.68 at 2 weeks, r = 0.53 at 3 weeks, r = 0.68 at 4 weeks, and r = 0.56 at 6 weeks. A positive correlation was found in all cases, except at week 1 when the correlation was weak; the IST and ISQ values decreased the most during the first postoperative week and increased during the second week. The IST values were also slightly higher at all measurement points.

Conclusion

The ability to assess implant stability without removing the abutment during healing is essential for determining the timing of loading without the risk of bone resorption. The results of this study suggest that AnyCheck® is useful for determining primary and secondary implant stability.

Fractal Dimension as a Tool for Assessment of Dental Implant Stability-A Scoping Review

A lot of modalities for assessing implant stability are available for clinicians, but they fail to assess trabecular changes as they are solely dependent on the operator's skills. The use of Fractal Dimension (FD) has evolved to be used as a measure for trabecular changes depicting implant stability before and after implant placement. The objective of this systematic review was to qualitatively analyse the available scientific literature describing the use of FD as a tool to measure implant stability on the basis of trabecular changes. An electronic search in PubMed, Web of Science and Scopus was carried out using relevant keywords, such as: fractal dimension; fractal analysis; dental implants; implant stability; osseointegration, etc. Studies reporting the use of FD as a tool to measure implant stability were included and subjected to qualitative analysis using ROBINS-I and Cochrane risk of bias assessment criteria. Fourteen studies were included in this review. Results showed that FD was found to be used solely as a measure of implant stability in seven studies, out of which six studies showed an increment in FD values. The majority of studies concluded with a statistical correlation between FD and respective other assessment methods used. FD may not serve as a sole indicator of implant stability; however, it can be used as an adjunct to conventional methods along with additional fractal factors.

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.

Primary Implant Stability Analysis of Different Dental Implant Connections and Designs-An In Vitro Comparative Study

Primary implant stability can be evaluated at the time of placement by measuring the insertion torque (IT). However, another method to monitor implant stability over time is resonance frequency analysis (RFA). Our aim was to examine the effect of bone type, implant design, and implant length on implant primary stability as measured by IT and two RFA devices (Osstell and Penguin) in an in vitro model. Ninety-six implants were inserted by a surgical motor in an artificial bone material, resembling soft and dense bone. Two different implant designs-conical connection (CC) and internal hex (IH), with lengths of 13 and 8 mm, were compared. The results indicate that the primary stability as measured by RFA and IT is significantly increased by the quality of bone (dense bone), and implant length and design, where the influence of dense bone is similar to that of CC design. Both the Osstell and Penguin devices recorded higher primary implant stability for long implants in dense bone, favoring the CC over the IH implant design. The CC implant design may compensate for the low stability expected in soft bone, and dense bone may compensate for short implant length if required by the anatomical bone conditions.

A comparative evaluation of the effect of platelet rich fibrin matrix with and without peripheral blood mesenchymal stem cells on dental implant stability: A randomized controlled clinical trial

Technological advances in the field of implantology have led to the concept of surface modifications to enhance implant stability by utilization of current concepts of tissue engineering and materials such as platelet concentrates and stem cells. The purpose of the present randomized controlled clinical trial was to evaluate and compare the effect of platelet rich fibrin matrix (PRFM) with and without peripheral blood mesenchymal stem cells (PBMSCs) on implant stability; by assessing the bone to implant contact (BIC) using resonance frequency analysis (RFA), insertion torque and also to establish and correlate the same with implant stability quotient (ISQ). A total of 15 patients with 30 sites ensuring a minimum of two dental implants adjacently placed in an edentulous area; with the age group of 25-50 years of both the sexes were categorized into Group 1 (dental implant with PRFM) and Group 2 (dental implant with PBMSCs embedded in PRFM). Insertion torque values at the time of dental implant placement and ISQ using RFA was recorded at 1 week, 1 month, and 3 months post operatively. There was no significant difference (p = 0.81) in Insertion torque values between both the groups (G1 and G2). Platelet rich fibrin matrix along with PBMSCs enhanced implant stability as higher and statistically significant ISQ values were noted at 1 week (p = 0.18), 1 month (p ≤ 0.001), and 3 months (p ≤ 0.001) intervals in the G2 group. Platelet rich fibrin matrix and PBMSCs showed promising results as a potential regenerative material for increasing and enhancing BIC and hence implant stability.

Stability of dental implants with sandblasted and acid-etched (SLA) and modified (SLActive) surfaces during the osseointegration period

Background. The surface properties of implants are effective factors for increasing the osseointegration and activity of osteoprogenitor cells. This study compared the stability of dental implants with sandblasted and acid-etched (SLA) and modified surfaces (SLActive) using the resonance frequency analysis (RFA). Methods. In a split-mouth design, 50 dental implants with either SLA surface properties (n=25) or modified (SLActive) surface properties (n=25) were placed in the mandibles of 12 patients with a bilateral posterior edentulous area. Implant stability was measured using RFA (Osstell) at implant placement time and every week for 1, 2, and 3 months before the conventional loading time. Results. One week following the implantation, implant stability increased from 70 to 77.67 for SLA and from 71.67 to 79 for SLActive (P < 0.05). Stability improved each week except in the 4th week in SLActive surface measurements. No significant differences were observed between the groups at 2 and 3 months (P > 0.05). Conclusions. For both implant surfaces, increased stability was observed over time, with no significant differences between the groups.

The impact of zero insertion torque on flapless immediate implant placement in the maxilla (5 years follow up clinical study)

Introduction: The achievement of good osseointegration in immediate implant placement can occur in the presence adequate primary stability. The insertion torque varies between cases depending on many factors. Aim: To assess clinically the impact of zero insertion torque on the survival of immediate implant placement in the maxilla for more than 5 years follow-up. Methods: A flapless immediate 2018 implants were in the maxilla in non-restorable single rooted teeth osteotomy site. The insertion torque of the implant was measured clinically by an integrated software. Results: The final insertion torque for 42 implants out of 2018 placed in fresh extraction sockets in the maxilla was zero (no primary stability). Their survival rate was 83.3%. Conclusions: The lack of certain conditions during immediate implant surgical installation and healing had the major effects on success. The loss of torque during immediate implant placement to zero may jeopardize the survival of the implants, but it may not be statistically significant with their failure and loss. The implant primary stability is not an absolute prerequisite to osseointegration; however, it may affect the implant survival rate.

Stability of Dental Implants and Thickness of Cortical Bone: Clinical Research and Future Perspectives. A Systematic Review

Dental surgery implantation has become increasingly important among procedures that aim to rehabilitate edentulous patients to restore esthetics and the mastication ability. The optimal stability of dental implants is correlated primarily to the quality and quantity of bone. This systematic literature review describes clinical research focusing on the correlation between cortical bone thickness and primary/secondary stability of dental fixtures. To predict successful outcome of prosthetic treatment, quantification of bone density at the osteotomy site is, in general, taken into account, with little attention being paid to assessment of the thickness of cortical bone. Nevertheless, local variations in bone structure (including cortical thickness) could explain differences in clinical practice with regard to implantation success, marginal bone resorption or anchorage loss. Current knowledge is preliminarily detailed, while tentatively identifying which inconclusive or unexplored aspects merit further investigation.

Clinical Evaluation of Dental Implants with a Double Acid-Etched Surface Treatment: A Cohort Observational Study with Up to 10-Year Follow-Up

BACKGROUND AND OBJECTIVES

The main purpose of this study was to evaluate the survival and success rates of dental implants with a double acid-etched surface treatment with evaluation times up to 10 years post-loading. Materials and Methods: This study was conducted at a hospital oral surgery and implantology unit. It included 111 dental implants with a double acid-etched surface. Three groups were created: Group 1 (1-3 years loading), Group 2 (3-5 years loading), and Group 3 (over 5 years loading). Probing depth, resonance frequency analysis (ISQ value), and marginal bone loss were evaluated. Results: The data obtained underwent statistical analysis. Overall, 78 patients were included in the study, who received, in total, 111 dental implants, all replacing single teeth. Mean probing depth was 3.03 mm and mean ISQ was 65.54. Regarding marginal bone loss, in Group 1, 67.6% of implants did not undergo any thread loss, in Group 2, 48.3%, and in Group 3, 59.6%; 59.10% of all implants did not present thread loss with a mean bone loss of 0.552 mm. The implant survival rate was 99.1%, and the success rate was 96.37%. Conclusions: Implants with a double acid-etched surface showed excellent success rates in terms of marginal bone loss, ISQ, and probing depth after up to 10 years of loading, making them a clinically predictable treatment option. Future studies are needed to compare this implant surface with other types in different restorative situations.

Can the design of the instruments used for undersized osteotomies influence the initial stability of implants installed in low-density bone? An in vitro pilot study

Objectives

The aims of this study were to compare the initial implant stability obtained using four different osteotomy techniques in low-density synthetic bone, to evaluate the instrument design in comparison to the implant design, and to determinate a possible correlation between the insertion torque and initial stability quotient (ISQ).

Materials and methods

Four groups were identified in accordance with the osteotomy technique used (n = 10 implants per group): group G1, osteotomy using the recommended drilling sequence; group G2, osteotomy using an undersized compactor drill; group G3, osteotomy using an undersized drill; and group G4, osteotomy using universal osseodensification drills. Two polyurethane blocks were used: block 1, with a medullary portion of 10 pounds per cubic foot (PCF 10) and with a 1 mm cortical portion of PCF 40, and block 2, with a medullary of PCF 15 and with a 2 mm cortical portion of PCF 40. Tapered implants of 4 mm in diameter and 11 mm in length were used. The insertion torque (IT) and ISQ were measured. The dimensions of the final instrument used in each group and the dimensions of the implant were used to calculate the total area of each part, and these data were compared.

Results

Differences between the four groups were found for IT and ISQ values depending on the technique used for the osteotomy in the two synthetic bone models (p < 0.0001). All groups showed lower values of initial stability in block 1 than in block 2.

Conclusions

Undersized osteotomies with instruments designed according to the implant body significantly increased the initial stability values compared to beds prepared with universal drills and using the drilling sequence standardized by the manufacturer.

Influences of screw design features on initial stability in immediate implant placement and restoration

BACKGROUND

Self-tapping screws have been extensively used for dental implants. Their biomechanical behavior is highly associated with their clinical success, particularly for screws used for immediate implant placement and restoration, because occlusal forces can directly affect the loading transfer at the bone-implant interface after implantation. The effect of implant design on the initial stability of self-tapping screws remains unclear. This study explored the biomechanical behaviors of implant stability in standardized implants with different design features.

METHODS

Six types of dental implants were designed using computer-aided design/computer-aided manufacturing technology, including three types of cutting flute shapes (spiral, straight, and non-self-tapping) combined with two types of screw features. Peak insertion torque values were first recorded; initial stability levels were subsequently evaluated in terms of the maximum force and resistance to lateral loads using an electrodynamic test system.

FINDINGS

The peak insertion torque values, maximum force, and resistance to lateral loads of the non-self-tapping groups were higher than those of the self-tapping groups by 17%-90% (p < 0.01). The peak insertion torque values of the Straumann implant with a spiral flute was higher than that of the original straight flute by 20% (p < 0.001). However, compared with the original spiral flute, the Nobel Biocare implant with straight flute had a 23% higher maximum force (p = 0.016) and 24.5% higher resistance (p = 0.012) under lateral loading.

INTERPRETATION

Changing the flute design would affect initial implant stability. Non-self-tapping implants exhibited superior initial stability than did self-tapping implants.

Reliability and Correlation of Different Devices for the Evaluation of Primary Implant Stability: An In Vitro Study

Our aim was to analyze the correlation between the IT evaluated by a surgical motor and the primary implant stability (ISQ) measured by two RFA devices, Osstell and Penguin, in an in vitro model. This study examines the effect of bone type (soft or dense), implant length (13 mm or 8 mm), and implant design (CC: conical connection; IH: internal hexagon), on this correlation. Ninety-six implants were inserted using a surgical motor (IT) into two types of synthetic foam blocks. Initial measurements for both the peak IT and ISQ were recorded at the point when implant insertion was stopped by the surgical motor, and the final measurements were recorded when the implant was completely inserted into the synthetic blocks using only the RFA devices. Our null hypothesis was that there is a good correlation between the devices, independent of the implant length, design, or bone type. We found a positive, significant correlation between the IT, and the Osstell and Penguin devices. Implant length and bone type did not affect this correlation. The correlation between the devices in the CC design was maintained; however, in the IH design it was maintained only between the RFA devices. We concluded that there is a high positive correlation between the IT and ISQ from a mechanical perspective, which was not affected by bone type or implant length but was affected by the implant design.

Effects of the Healing Chambers in Implant Macrogeometry Design in a Low-Density Bone Using Conventional and Undersized Drilling

Background:

The ideal installation technique or implant macrogeometry for obtaining an adequate osseointegration in low-density bone tissue follows a challenge in the implantology.

Aims and Objective:

The aim of the present study was to evaluate the behavior of three osteotomy techniques and two implant macrogeometries in two low-density polyurethane blocks. The insertion torque (IT), initial stability, pullout resistance, and weight of the residual bone material deposited on the implants were assessed.

Materials and Methods:

A total of 120 implants with two different macrogeometries were used. They were divided into six groups according to the implant macrogeometry and the drilling technique performed (n = 20 implants per group). The implants were installed in polyurethane blocks with pounds per cubic foot (PCF) 10 and PCF 20 densities. The IT, initial stability, pullout resistance, and weight residual bone were measured.

Results:

Differences were found in the values referring to the macrogeometry of the implants and the type of osteotomy performed. In all groups, the initial stability of the PCF 10 blocks was quite low. The undersized osteotomies significantly increased the values measured in all tests in the PCF 20 density blocks.

Conclusions:

In conclusion, even when a modified (undersized) osteotomy technique is used, implants inserted in low-quality bone (type IV) can present problems for osseointegration due their low initial stability and bone resistance. However, the modification in the implant macrogeometry (with healing chambers) presented more quantity of bone on the surface after the pullout test.

Resonance frequency analysis of implants placed in condensed bone

Objectives

Resonance frequency analysis (RFA) is used to monitor implant stability. Its output, the Implant Stability Quotient (ISQ), supposedly correlates with insertion torque, a common measurement of primary stability. However, the reliability of RFA in condensed bone remains unclear.

Material and methods

In this human cadaver study in edentulous jaws and fresh extraction sockets, implants were inserted using a split‐mouth approach into condensed or untreated bone. Mean ISQ, peak insertion torque, and pre‐ and postoperative bone volume fractions (BV/TV) were assessed.

Results

In edentulous jaws, insertion torque and ISQ correlated both in untreated (r = 0.63, p = 0.02) and in condensed (r = 0.82, p  < 0.01) bone. In extraction sockets, insertion torque and ISQ only correlated in untreated (r = 0.78, p < 0.01), but not in condensed bone (r = 0.15, p = 0.58). In all edentulous jaws, preoperative BV/TV correlated with insertion torque (r = 0.90, p < 0.0001), ISQ (r = 0.64, p < 0.001), and changes in BV/TV (r = –0.71, p < 0.01). In all extraction sockets, preoperative BV/TV did not correlate with either insertion torque (r = 0.33, p = 0.15), ISQ (r = 0.38, p = 0.09), or changes in BV/TV (r = –0.41, p = 0.09). Joint analysis identified preoperative BV/TV as a predictor of postoperative BV/TV (p < 0.001), insertion torque (p < 0.001), and ISQ (p < 0.001).

Conclusions

RFA is feasible for monitoring stability after late implant placement into condensed bone, but not after immediate placement into condensed fresh extraction sites.

A Vibratory, Subresonant Diagnostic Device to Measure Dental Implant Stability Via Angular Stiffness

Stability of a dental implant reflects quality of osseointegration between the implant and its surrounding bone. While many methods have been proposed to characterize implant stability, angular stiffness at the neck of the implant has been proven to be a rigorous and accurate measure. Nevertheless, fast and reliable measurements of the angular stiffness in a clinical environment are not yet available. This article is to demonstrate a novel stability diagnostic device that can measure the angular stiffness accurately in clinical environments. The device consists of a sensing unit, a controller unit, and a mobile app. In the sensing unit, a coupler attaches a buzzer motor and a tiny accelerometer to an abutment of an implant, whose angular stiffness is to be measured. The buzzer vibrates at a frequency below the resonance frequency of the implant–bone–abutment system. Meanwhile, the accelerometer measures the abutment's vibration. The controller unit powers the buzzer, reads the accelerometer data, and transmits the data to the mobile app. The mobile app postprocesses the data and extracts the angular stiffness through use of a finite element model and a nonlinear regression algorithm. The extracted angular stiffness is compared with a calibrated angular stiffness, which is obtained independently via a force hammer and a laser Doppler vibrometer. The comparison shows reasonable agreement, with the difference being in the range of 4–20%.

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.

Osseodensification effect on implants primary and secondary stability: Multicenter controlled clinical trial

Background

Osseodensification (OD) has shown to improve implant stability; however, the influences of implant design, dimensions, and surgical site characteristics are unknown.

Purpose

To compare the insertion torque (IT) and temporal implant stability quotients (ISQ) of implants placed via OD or subtractive drilling (SD).

Materials and Methods

This multicenter controlled clinical trial enrolled 56 patients, whom were in need of at least 2 implants (n = 150 implants). Patients were treated with narrow, regular, or wide implants and short, regular, or long implants in the anterior or posterior region of the maxilla or in the posterior region of the mandible. Osteotomies were performed following manufacturers recommendation. IT was recorded with a torque indicator. ISQ was recorded with resonance frequency analysis immediately after surgery, 3 and 6 weeks.

Results

Data complied as a function of osteotomy indicated significantly higher IT for OD relative to SD. OD outperformed conventional SD for all pairwise comparisons of arches (maxilla and mandible) and areas operated (anterior and posterior), diameters and lengths of the implants, except for short implants. Overall, ISQ data also demonstrated significantly higher values for OD compared to SD regardless of the healing period. Relative to immediate readings, ISQ values significantly decreased at 3 weeks, returning to immediate levels at 6 weeks; however, ISQ values strictly remained above 68 throughout healing time for OD. Data as a function of arch operated and osteotomy, area operated and osteotomy, implant dimensions and osteotomy, also exhibited higher ISQ values for OD relative to SD on pairwise comparisons, except for short implants.

Conclusions

OD demonstrated higher IT and temporal ISQ values relative to SD, irrespective of arch and area operated as well as implant design and dimension, with an exception for short implants. Future studies should focus on biomechanical parameters and bone level change evaluation after loading.

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.

Cone Morse Implant Placement in Patients With Aids Who Use Highly Active Antiretroviral Therapy Report of Clinical Cases

Introduction:

The Acquired Immune Deficiency Syndrome (AIDS) is a condition that manifests itself after the infection of the human organism by the Human Immunodeficiency Virus (HIV). In 1996, the Highly Active Antiretroviral Therapy (HAART) was introduced, with the aim of slowing down the immunodeficiency and restoring the immunity of these patients, extending their life expectancy. Consequently, the need for rehabilitating dental treatments arose, aiming to improve oral health, self-esteem and the quality of life of these patients. This current study was designed to assess vertical dimensional changes in the peri-implant bone level around the placement of dental implants in AIDS patients using HAART.

Materials and Methods:

For the bone level evaluation, at first cone-beam computed tomography, panoramic radiography and periapical radiographs were used during the periods at baseline, 2, 4 and 6 months after the implant installation. The images were digitized and analyzed on programs Adobe Photoshop CS5 and Digimizer 3.1.1.0.

Results:

Were installed 13 implants that presented a peri-implant bone loss average of 0.26 mm in the first bimester, 0.13 mm in the second and 0.18 mm in the third, totalizing a peri-implant bone loss average of 0.57 mm in the semester.

Conclusion:

Despite the several metabolic changes that can affect these patients due to infection, drug therapy, immune response and the absence of an adequate stability quotient and insertion torque, all implants showed osseointegration, as well as the parameters of clinical success after the installation of the implant, and the degree of bone loss in this period is within the expected according to the research.

Clinical Relevance:

Oral health professionals should be aware of the possible complications that future HIV patients may have due to their systemic and drug-related condition in association with osseointegration.

Maximum insertion torque loss after miniscrew placement in orthodontic patients: A randomized controlled trial

OBJECTIVES

To compare torque recordings of immediately loaded orthodontic miniscrews between insertion time and different post-placement timepoints (2 weeks, 4 weeks and removal time, respectively).

SETTING AND SAMPLE POPULATION

Parallel trial with an allocation ratio of 1:1. Eligibility criteria were needs of fixed orthodontic treatment, no systemic disease and absence of using drugs altering bone metabolism.

MATERIAL AND METHODS

Patients received miniscrews, 2.0 mm diameter and 10 mm length. All miniscrews underwent inter-radicular placement, and they were placed in the maxilla or in the mandible, palatally or buccally. No pre-drilling was performed. Miniscrews were loaded immediately after the insertion and were used for distalization, intrusion, extrusion, mesialization or indirect anchorage. Patients were randomly divided into three groups. For each patient, Maximum Insertion Torque (MIT) was evaluated at baseline. MIT was measured again after 2 weeks and after 4 weeks by tightening the screw a quarter of turn in Groups 1 and 2, respectively. At the end of the treatment, maximal removal torque was evaluated in Group 3. Torque variation with respect to insertion time was considered as the primary outcome. Baseline and longitudinal differences were tested using the linear mixed-effects (LME) model.

RESULTS

Forty seven patients and 74 miniscrews were followed up. An association existed between maximum insertion torque and the observation time. A torque decrease of 26.9% and 30% after 2 weeks was observed for mandibular and maxillary miniscrews, respectively. After 1 month, torque values were similar to the baseline records. The overall success rate was 79.7%. No serious harm was observed.

CONCLUSIONS

Maximum insertion torque undergoes a loss during the first 2 weeks, and its values may depend on the insertion site and the anchorage purpose. Removal torque value is almost the same as the initial torque after 1 month.

Can Bone Compaction Improve Primary Implant Stability? An In Vitro Comparative Study with Osseodensification Technique

Background: This study aims to analyze bone compaction and osseodensification techniques and to investigate how cancellous bone compaction could influence primary implant stability (PS). Methods: Two different surgical protocols (bone compactors—BC; osseodensification drills—OD) were compared by placing 20 implants into 20 fresh pig ribs for each procedure. Peak insertion torque (PIT) and peak removal torque (PRT) were investigated using an MGT-12 digital torque gauge, and implant stability quotient (ISQ) was analyzed using an Osstell® Beacon device. Results: Analysis of our data (T-test p < 0.05) evidenced no statistically significant difference between BC and OD in terms of PIT (p = 0.33) or ISQ (p = 0.97). The comparison of PRT values showed a statistically significant difference between BC and OD protocols (p = 0.009). Conclusions: Cancellous bone compaction seems to improve PS, preserving a significant amount of bone and evenly spreading trabeculae on the entire implant site. While the PIT and ISQ values obtained are similar, the PRT values suggest different physical responses from the surrounding bone tissue. Nevertheless, a larger sample and further in vivo studies are necessary to validate the usefulness of BC protocol in several clinical settings.

The Influence of Nanostructured Hydroxyapatite Surface in the Early Stages of Osseointegration: A Multiparameter Animal Study in Low-Density Bone

Background and Objective

The success rates of dental implants in low-density bone have been reported as a challenge, especially for early or immediate loading in the maxilla posterior area. Nanoscale architecture affects the roughness, surface area, surface energy of the implant and can enhance osseointegration. This study aimed to evaluate the implant-surface topography and biomechanical, histomorphometric, and histological bone responses to a new nanostructured hydroxyapatite surface placed in the iliac crest of sheep.

Methods

Ten female sheep (2–4 years) received 30 implants (n=10/group): HAnano^® coated (Epikut Plus^®, S.I.N. Implant System, Sao Paulo, SP, Brazil), SLActive (BLX^®, Straumann, Basel, Switzerland), and TiUnite (NobelActive^®, Nobel Biocare, Göteborg, Sweden) surfaces. Scanning electron microscopy with energy-dispersive spectroscopy evaluated the implant surface topography, the insertion torque value, and resonance frequency analysis evaluated the primary stability, bone-implant contact, and bone-area fraction occupancy were evaluated after 14 and 28 days after implant placement.

Results

The surface morphology was considerably comparable between the implant groups’; however, the TiUnite^® group presented a remarkable different surface. The SLActive^® and TiUnite^® groups presented an insertion torque average of 74 (±8.9) N/cm that was similar to that of HAnano^® 72 (±8.3) N/cm (p >0.05). The resonance frequency evaluated with Osstell^®/SmartPeg^® or Penguin^®/MulTipeg^® showed similar results when assessing implants from the same group. BIC and BAFO significantly increased (p<0.05) throughout the experimental periods to all groups, but BIC and BAFO values were similar among the implants at the same time point. After 4 weeks, bone-implant contact was higher than 80% of the total length analyzed. New bone occupies around 60% of analyzed area around the implants.

Conclusion

HAnano^® coated surface promoted comparable osseointegration as SLActive and TiUnite in the sheep model. The three tested surfaces showed comparable osseointegration at the early stages of low-density bone repair in the sheep model.

Alveolar Bone Density and Width Affect Primary Implant Stability

Primary implant stability (PIS) depends on surgical technique, implant design, and recipient bone characteristics, among other factors. Bone density (BD) can be determined in Hounsfield units (HUs) using cone beam computerized tomography (CBCT). Reliable prediction of PIS could guide treatment decisions. We assessed whether PIS was associated with recipient bone characteristics, namely, BD and alveolar ridge width (ARW), measured preoperatively by CBCT. We studied a convenience sample of 160 implants placed in 48 patients in 2016 and 2017. All underwent CBCT with a radiologic/surgical guide yielding values for ARW and BD. PIS measures used were the implant stability quotient (ISQ) from resonance frequency analysis and insertion torque (IT). IT was most influenced by the HU value at 0.5 mm outside the implant placement area, followed by the value within this area, and ISQ by the HU value at 0.5 mm outside the placement area, followed by implant placement site and apical ARW. ISQ values were significantly related to ARW in coronal (P < .05), middle (P < .01), and apical (P < .01) thirds. ISQs were higher with larger-diameter implants (P < .01). ISQ and IT were strongly correlated (P < .001). PIS in terms of ISQ and IT is positively correlated with edentulous alveolar ridge BD measured by CBCT, implying that implant stability may be predicted preoperatively. Wide alveolar ridges favored lateral PIS but did not affect rotational PIS. The most significant predictor of lateral and rotational PIS in our patients was the HU value at 0.5 mm outside the implant placement area.

Effect of low-level laser therapy on osseointegration of titanium dental implants in ovariectomized rabbits: biomechanics and micro-CT analysis

PURPOSE

The primary aim of this study is to assess, in an animal model, whether biostimulation of osteoporotic bone with low-level laser therapy improves the osseointegration of dental implants.

MATERIAL AND METHODS

Twenty-two female rabbits were randomly divided into two groups: sham-ovariectomy and bilateral-ovariectomy. Laser therapy was applied to the implants placed in the right tibial bones and was not applied to implants placed in the left tibial bones. The periotest device was used for the stability test. Periotest values were recorded after the implantation (T0) and when the animals were euthanized (T1). The removal torque test and micro-computed tomography examination were evaluated.

RESULTS

As a result of removal torque, the mean of ovariectomy-laser group (56.1 ± 5.1 Ncm) was higher than sham-ovariectomy group (55.4 ± 18.5 Ncm) (p = 0.9). In periotest analysis, a significant difference was found between the values of T1 and T0 in all groups, except sham-ovariectomy group (p < 0.05); and the highest difference was found in the ovariectomy-laser group. Micro-CT examination demonstrated that ovariectomy-laser group showed an increase of implant-bone contact when compared with ovariectomy (p < 0.05).

CONCLUSIONS

The values obtained from biomechanical tests and micro-CT in the ovariectomy-laser group were significantly higher than the ovariectomy group and achieved the values in the healthy bone.