Resonance Frequency Analysis Values Research Articles

Evaluation of Implant Stability Quotient of Sandblasted Acid-Etched (SAE) and Chemical-Modified SAE Dental Implants: A Clinical Study

ABSTRACT Objectives: The goal of the current research was to assess the implant stability quotient (ISQ) of dental implants that were chemically changed with SAE and without SAE. Materials and Methods: Patients in the current study had dental implants fitted with SAE (Group I) and chemically altered SAE (Group II). After implant implantation, resonance frequency analysis (RFA) was performed as soon as possible as well as one, three, six, nine, and twelve weeks later. Version 23.0 of SPSS Statistics for Windows was used to statistically analyze the results. Result: In SAE dental implants (Group I), a highest RFA value of 84.1 and a minimum value of 42.2 were noted. In chemically modified implants, the SAE (group II) mean RFA value ranged from 30.3 to 87.1. Conclusion: It has been noted that dental implants with surface treatment exhibit increased implant–bone osseointegration. Implants with hydrophilic surfaces osseointegrate more quickly than those with SAE areas.

Implant Survival in Renal-Transplanted Patients: A Prospective Long-Term Study.

The present study aims to assess the feasibility of implant rehabilitation in kidney-transplanted patients. Patients with kidney transplantation included in periodontal supportive care and at least one year of dialysis with mono- or partial edentulism were eligible for this study. Histomorphometric evaluation of the harvested bone was matched with radiological bone assessment. Implant stability was also monitored with resonance frequency analysis and insertion torque value. Fixed cemented prostheses have been delivered after conventional loading protocol. Supportive periodontal therapy has been administered. Eleven patients (9 males and 2 females) were included. The mean age was 58.1 ± 9.9 years. A total of 17 implants were inserted and analyzed. Mean ITV was 39.3 ± 23.8 Ncm. The mean primary stability (implant stability quotient) at T0 was 71.7 ± 10.5, whereas the mean secondary stability at T1 was 73.0 ± 7.3. The minimum follow-up was 62 months, with a maximum of 84 months (7 years) reached by 4 patients. Fourteen out of 15 implants were in function at a 5-year follow-up (survival rate: 93.3%). Two implants showed peri-implantitis. Seventeen bone samples were collected (13 in the mandible and 4 in the maxilla). The mean percentage of marrow spaces and lamellar bone was 41.6% and 58.4%, respectively. Class 3, according to Misch classification, was found as the mean value of radiological bone density. It can be concluded that implant-supported rehabilitation in kidney-transplanted patients is possible. Adequate periodontal maintenance allows implant rehabilitation in kidney-transplanted patients with long-term sufficient survival rates.

Effect of Commonly Prescribed Medications on Osseointegration and Implant Stability

Background: Osseointegration, the process by which implants integrate with surrounding bone, is crucial for the success of dental implants. However, the impact of commonly prescribed medications on osseointegration and implant stability remains a topic of interest and concern within the field of implant dentistry. Materials and Methods: In this study, we conducted a retrospective analysis of patients who received dental implants between 2018 and 2020. Patients were categorized based on their medication usage at the time of implant placement. Medications included in the analysis were divided into groups such as bisphosphonates, corticosteroids, selective serotonin reuptake inhibitors (SSRIs), and non-steroidal anti-inflammatory drugs (NSAIDs). Implant stability was assessed using resonance frequency analysis (RFA), and osseointegration was evaluated through radiographic examination. Results: A total of 150 patients were included in the study, with 50 patients in each medication group. The mean RFA values for patients on bisphosphonates, corticosteroids, SSRIs, NSAIDs, and control group were 67, 72, 69, 71, and 75 ISQ, respectively. Radiographic evaluation revealed osseointegration rates of 80, 85, 75, 82, and 90% for the respective medication groups. Conclusion: Our findings suggest that commonly prescribed medications may have varying effects on osseointegration and implant stability. While corticosteroids and NSAIDs seem to have minimal impact, bisphosphonates and SSRIs may potentially hinder osseointegration and decrease implant stability. Clinicians should consider patients’ medication history when planning dental implant procedures and closely monitor implant integration in patients taking these medications

A Comparative Study of Two Resonance Frequency Analysis Instruments

Primary implant stability (PIS) depends on the surgical technique, implant design, and the characteristics of the recipient bone, among other factors. This paper aims to study different parameters (recipient bone characteristics like bone density (BD) and mean alveolar crest width (MACW)) that may be related to implant primary stability outcomes. With that, it can be determined if they are reliable PIS methods and guide treatment decisions for successful implant outcomes. Thirty-five dental implants (25 BTI Interna® CORE and 10 Bioner Top DM) were placed in 10 patients in 2022 and 2023. All of them underwent Cone Beam Computed Tomography (CBCT) scans to obtain values for MACW and BD. PIS measurements used were implant stability quotient (ISQ) obtained through different resonance frequency analysis (RFA) methods (Osstell® ISQ and Penguin RFA®) and insertion torque (IT). The results for the following variables showed significance at p<0.001 and p<0.05. Highly significant relationships were observed between Osstell and Penguin RFA values (p<0.001). Regarding IT, a direct proportional relationship with ISQ was observed (p<0.05). PIS, as measured by ISQ and IT, did not show a significant correlation with the mean alveolar crest width of the edentulous ridge measured by CBCT, suggesting that wide or narrow alveolar crests did not have an effect on rotational or lateral PIS in both implant groups. The most significant predictor of lateral and rotational PIS in our patients was the Hounsfield Units (HU) value 0.5 mm away from the implant placement area (p<0.001) and (p<0.05), respectively. In conclusion, non-invasive PIS methods could be considered as a guide for clinicians in treatment decision-making and implant success. However, further research is needed to predict PIS.

The influence of truncated-conical implant length on primary stability in maxillary and mandibular regions: an in vitro study using polyurethane blocks.

This in vitro study is aimed at assessing whether implant primary stability is influenced by implant length in artificial bone with varying densities. A total of 120 truncated-conical implants (60 long-length: 3p L, 3.8 × 14 mm; 60 short-length: 3p S, 3.8 × 8 mm) were inserted into 20, 30, and 40 pounds per cubic foot (PCF) density polyurethane blocks. The insertion torque (IT), removal torque (RT), and resonance frequency analysis (RFA) values were recorded for each experimental condition. In 30 and 40 PCF blocks, 3p S implants exhibited significantly higher IT values (90 and 80 Ncm, respectively) than 3p L (85 and 50 Ncm, respectively). Similarly, RT was significantly higher for 3p S implants in 30 and 40 PCF blocks (57 and 90 Ncm, respectively). However, there were no significant differences in RFA values, except for the 20 PCF block, where 3pS implants showed significantly lower values (63 ISQ) than 3p L implants (67 ISQ) in both the distal and mesial directions. These results demonstrated that the implant's length mainly influences the IT and RT values in the polyurethane blocks that mimic the mandibular region of the bone, resulting in higher values for the 3p S implants, while the RFA values remained unaffected. However, in the lowest density block simulating the maxillary bone, 3p L implants exhibited significantly higher ISQ values. Therefore, our data offer valuable insights into the biomechanical behavior of these implants, which could be clinically beneficial for enhancing surgical planning.

Insertion Torque and Resonance Frequency Analysis in Tapered and Parallel Dental Implants.

Primary implant stability (PIS) is known to vary with recipient bone mass and density, dental implant design and surgical technique. The objective of this preliminary study was to compare rotational and lateral PIS of same-coronal-diameter conical and parallel implants, using insertion torque recorded with a dental implant motor set and implant stability quotient obtained from resonance frequency analysis (performed with both Osstell and Penguin systems) as measures of rotational and lateral stability, respectively. Additionally, the relationship between PIS and alveolar ridge width (ARW) was explored in both implant types. Sixty dental implants (30 tapered and 30 parallel) were randomly placed with a split-mouth design in 17 patients. Bone density and ARW were estimated from cone beam computed tomography images taken with radiological-surgical templates. Density and width values were similar in the 2 groups (P > .05). Implant coronal diameters were 3.75 mm in all cases, while consistent with the manufacturer's recommendations, final drill bit diameters used were 3.25 and 3.4 mm for parallel and tapered implants, respectively. Insertion torque was higher (P < .05) with parallel implants, but between-group differences in implant stability quotient were not significant (P > .05). In tapered implants, insertion torque was inversely correlated with ARW (P < .001). Notably, significant differences were observed between resonance frequency analysis values from Osstell and Penguin systems (P < .001). In conclusion, future studies should explore how PIS may be influenced by final drill bit size regardless of implant design and potential limits on the effectiveness of tapered implants to achieve good stability in thick low-density bone.

Effect of Drilling Preparation on Immediately Loaded Implants: An In Vivo Study in Sheep.

To determine the biologic and biomechanical effects of two implant drilling protocols on the cortical bone around implants subjected to immediate loading. A total of 48 implants were inserted into the mandibles of six sheep following one of two drilling protocols: undersized preparation (US; n = 24) and nonundersized preparation (NUS; n = 24). Immediately after implant insertion, an abutment was placed on each implant and 36 implants were subjected to 10 sessions of dynamic vertical loads (1,500 cycles, 1 Hz) of 25 N or 50 N. Insertion torque value (ITV) was recorded at implant installation. Resonance frequency analysis (RFA) was measured at implant insertion and at each loading session. Fluorochrome was administered at day 17, and the animals were euthanized after 5 weeks. The removal torque values (RTVs) were measured, and samples underwent histomorphometric, μCT (microcomputed tomography), and fluorescence image acquisition analyses. The bone volume density (BV/TV), bone-to-implant contact (BIC), bone area fraction occupancy (BAFO), and fluorochrome stained bone surface (MS) were calculated. A linear mixed model analysis was performed, and Pearson paired correlation was calculated. Five implants from the NUS group failed, with a mean ITV of 8.8 Ncm and an RFA value of 57. The mean ITVs for US group and NUS group were 80.5 (± 14) Ncm and 45.9 (± 25) Ncm, respectively (P < .001). No differences were noted in the RFA values from the time of implant insertion until the end of the study. No differences in RTV, BV/TV, BAFO, or MS were observed between the groups. Intense new bone formation took place in the NUS group implants that were subjected to load. Undersized preparation of cortical bone ensured a greater BIC compared to a nonundersized preparation. Moreover, this study demonstrated that immediate loading did not interfere with the osseointegration process, but loading induced intense new bone formation in the NUS group. It is not recommended to immediately load the implants when the clinically perceived primary stability is lower than an ITV of 10 Ncm and an RFA value of 60. Int J Oral Maxillofac Implants 2023;38:607-618. doi: 10.11607/jomi.9949.

Primary Stability Assessment of Conical Implants in Under-Prepared Sites: An In Vitro Study in Low-Density Polyurethane Foams

Bone characteristics, the implant macrogeometry, and the drilling technique are considered the main important factors to obtain a good implant primary stability (PS). Indeed, although it is known that implant placement in poor bone sites increases the possibility of implant failure, several surgical procedures have been proposed to improve PS, such as site under-preparation. Hence, this in vitro study aimed to evaluate the insertion torque (IT), removal torque (RT), and resonance frequency analysis (RFA) of conical implants (3.3 and 4 × 13 mm) placed in under-prepared sites on 10 and 20 pounds per cubic foot (PCF) density polyurethane sheets (simulating a D3 and D2 bone, respectively) with and without a cortical sheet of 30 PCF in density (corresponding to a D1 bone). After using ANOVA or Kolmogorov–Smirnov test to elaborate data, the resulting IT and RT values were directly proportional to the polyurethane block densities (e.g., the lowest and highest IT values were 8.36 ± 0.52 Ncm in the 10 PCF density sheet and 46.21 ± 0.79 Ncm in the 20 PCF density sheet + cortical for 4 × 13 mm implants) and increased with the increasing amount of site under-preparation (the highest results for both implants were found with a 2.2 mm under-preparation, showing a significantly higher IT with a p &lt; 0.05 compared with others, especially in the highest-density sheets). Both implants inserted in the 20 PCF density block + cortical with all under-preparation protocols exhibited significantly higher RFA values (p &lt; 0.05–0.0001) compared with the corresponding ones in the 10 PCF block. Moreover, 3.3 × 13 mm implants showed the same results comparing the 20 PCF block and the 10 PCF block + cortical. In conclusion, in this in vitro study using low-density polyurethane blocks, the under-preparation of the implant insertion sites was shown to be effective in increasing implants’ PS.

Are Implant Threads Important for Implant Stability? An In Vitro Study Using Low-Density Polyurethane Sheets

Different strategies are known to improve implant primary stability (PS) and the bone-to-implant contact in post-extractive conditions, such as the macro-geometry of screws and apical threads, which can enhance the mechanical characteristics. In any case, the role of the apical area design in maintaining or improving the PS, especially in low-quality bone, still remains unclear. Thus, the present study aimed at evaluating in vitro the Insertion Torque (IT), Removal Torque (RT), and Resonance Frequency Analysis (RFA) of different implant apical threads in a cylindrical (EE) and in three conical implants (T3, TAC, Intra-lock) inserted in simulated post-extraction conditions on low-density polyurethane foams of 10 and 20 pounds per cubic foot (PCF), with and without the addition of a cortical sheet of 30 PCF in density. The IT, RT, and RFA values of all the implants tested were directly proportional to the polyurethane density and to the presence of the cortical sheet, but TAC and Intra-lock implants, which had the latest-generation thread design, always showed significantly higher values (e.g., IT: 18.6 and 18.6 Ncm, RT: 10.8 and 13.7 Ncm, RFA mean: 46 and 43 ISQ, in the 20 PCF density with the cortical sheet for TAC and Intra-lock, respectively). In particular, TAC implants also reached the highest RFA values in the lowest-density foam (19 ISQ). In conclusion, the present in vitro study demonstrated that TAC and Intra-lock apical designs and macro-geometries could play a key role in determining the PS and the polyurethane-implant contact in simulated post-extraction conditions in low-density artificial bone.

Primary Stability Evaluation of a Novel Tapered Implant Inserted in Low-Density Bone Sites: An In Vitro Study.

Purpose: To evaluate primary stability of a new dental implant design in low-density bone sites, compare it with another implant design previously studied in the same bone density, and explore possible correlations between primary stability parameters. Materials and Methods: The study was carried out on fresh humid bovine bone classified as type III. The test group consisted of 30 DS Prime Taper implants (PT), and the control group consisted of 30 Astra Tech EV implants (EV). All the implants were inserted according to the protocol provided by the manufacturer. After placement, variable torque work (VTW), peak insertion torque (pIT), and resonance frequency analysis (RFA) were recorded. Results: Mann-Whitney test showed that the mean VTW and pIT were significantly higher in the test group PT compared to the control group EV; furthermore, statistical analysis showed that the mean RFA was slightly higher in the control group EV but without reaching statistical significance. Pearson correlation analysis showed a very strong positive correlation between pIT and VTW values in both groups; furthermore, it showed a positive correlation between pIT and RFA values and between VTW and RFA values again in both groups. Conclusion: The results showed that the novel tapered implants were able to reach good primary stability in low-density bone sites and that this was superior to parallel-walled implants when measured with VTW and pIT. Moreover, a statistically significant correlation was found between the three methods used to measure implant primary stability.

Comparison of Primary Stability of Two Different Implants DesignsA Prospective Clinical Study

Introduction: Any implant treatment must begin with successful implant integration. The effectiveness of implant osseointegration is determined by various factors, including implant design, implant diameter and density, and surgical technique. Osseointegration is dependent on implant design. Aim: To assess the primary stability of tapered and cylindrical implants by using Resonance Frequency Analysis (RFA) and Insertion Torque Values (ITV). Materials and Methods: This in-vivo, prospective clinical study was conducted in the Department of Prosthodontics at Sibar Institute of Dental Sciences, Guntur, Andhra Pradesh, India in the month of November 2019. Twenty patients were selected for the study. Tapered Bioline implants (Bioline Dental GmbH &amp; Co. KGGermany) were spaced in 10 patients (group 1) and cylindrical Bioline implants (Bioline Dental GmbH &amp; Co. KG-Germany) in the other 10 patients (group 2). For both implant designs, primary stability was assessed immediately after implant placement using RFA by Osstell Mentor and ITV by a torque wrench. KolmogorovSmirnov test, Shapiro-Wilk test were used for checking normality. Mann Whitney U test, Independent t tests, Spearman correlation tests were done by using software Statistical Package for Social Sciences (SPSS) Version 23.0. Results: The mean ISQ (Implant Stability Quotient) for tapered implants was 76.6±2.3, and for cylindrical implants mean ISQ is 59.75±4.2 (p-value &lt;0.001). The mean ITV for tapered implants was 43.5±2.58 Ncm, and for cylindrical implants, the mean ITV was 33±4.21 Ncm (p-value &lt;0.001). The correlation between ITV and RFA was 0.928 which was highly significant (p&lt;0.001**). Conclusion: Within the scope of this investigation, tapered implants showed better primary stability than cylindrical-shaped implants as determined by ISQ and insertion torque values. ITV and ISQ values showed a positive correlation in determining the primary stability of implants.

Insertion Torque, Removal Torque, and Resonance Frequency Analysis Values of Ultrashort, Short, and Standard Dental Implants: An In Vitro Study on Polyurethane Foam Sheets.

Short implants were introduced to reduce morbidity, treatment duration, and complex bone regeneration interventions in atrophic jaws and to improve patient-reported outcomes. This study aimed to determine the insertion torque (IT), removal torque (RT), and resonance frequency analysis (RFA) values of ultrashort (3 mm length), short (7 mm length), and standard implants (10 mm length) inserted in 1-, 2-, 3-, and 4-mm thickness polyurethane sheets with densities of 10, 20, and 30 pounds per cubic foot (PCF). Standard-length implants were the gold standard (control). Overall, short-length implant IT values were higher or similar to the control in most experimental conditions. Those inserted into a 3 mm/30 PCF lamina showed the highest IT values, whereas 5 mm diameter ultrashort-length implants inserted into 2 and 3 mm/20 PCF laminas were higher than other implants. RT values followed the same trend and RFA values were more appreciable in short- and standard-length implants in all the scenarios. However, ultrashort-length implants reached a primary stability comparable to that of standard implants in lower thicknesses. In conclusion, although further studies are needed to corroborate this in vitro model with preclinical and clinical studies, our data shed light on short- and ultrashort-length implants geometries to a potential application in critical atrophy of the posterior jaws.

Survival and stability of strategic mini-implants with immediate or delayed loading under removable partial dentures: a 3-year randomized controlled clinical trial

ObjectivesStability values of mini-implants (MIs) are ambiguous. Survival data for MIs as supplementary abutments in reduced dentitions are not available. The aim of this explorative research was to estimate the 3-year stability and survival of strategic MIs after immediate and delayed loading by existing removable partial dentures (RPDs).Material and methodsIn a university and three dental practices, patients with unfavorable tooth distributions received supplementary MIs with diameters of 1.8, 2.1, and 2.4 mm. The participants were randomly allocated to group A (if the insertion torque ≥ 35 Ncm: immediate loading by housings; otherwise, immediate loading by RPD soft relining was performed) or delayed loading group B. Periotest values (PTVs) and resonance frequency analysis (RFA) values were longitudinally compared using mixed models.ResultsA total of 112 maxillary and 120 mandibular MIs were placed under 79 RPDs (31 maxillae). The 1st and 3rd quartile of the PTVs ranged between 1.7 and 7.8, and the RFA values ranged between 30 and 46 with nonrelevant group differences. The 3-year survival rates were 92% in group A versus 95% in group B and 99% in the mandible (one failure) versus 87% in the maxilla (eleven failures among four participants).ConclusionsWithin the limitations of explorative analyses, there were no relevant differences between immediate and delayed loading regarding survival or stability of strategic MIs.Clinical relevanceThe stability values for MIs are lower than for conventional implants. The MI failure rate in the maxilla is higher than in the mandible with cluster failure participants.Clinical trial registrationGerman Clinical Trials Register (Deutsches Register Klinischer Studien, DRKS-ID: DRKS00007589, www.germanctr.de), January 15, 2015.

Osteointegration assessment by the resonant frequency analysis method in patients with different bone mineral density (clinical and biomechanical aspects): prospective study

BACKGROUND: Dental implant stability depends on the mechanical bone properties in the area of the planned surgical intervention and the correctness of the implant embedded in the bone tissue. A significantly decreased bone tissue mineral density of the jaws was found in patients with osteoporosis, which complicates or even prevents the restoration of the integrity of the dentition by the dental implantation method.&#x0D; AIM: This study aimed to conduct a comparative assessment of the effectiveness of the treatment of dentition defects by dental implantation in patients with a normal state of bone tissue, osteopenia, and osteoporosis, to assess the stability of the installed implants using the resonance frequency analysis.&#x0D; MATERIALS AND METHODS: All patients underwent a densitometric study using double X-ray photon absorptiometry, in addition to the basic examination, in dental implantation operation preparation, which made it possible to identify systemic and regional changes in bone mineral density. Dental implant stability and osseointegration were controlled by the resonant frequency analysis method.&#x0D; RESULTS: The parameters of resonance frequency analysis in patients with normal bone mass, osteopenia, and osteoporosis vary depending on the area where the implants are installed when studying the implant stability in patients with different bone mineral densities. The overall index of resonance frequency analysis values differed from those of the group with osteopenia and osteoporosis, regardless of the area of implants installed in patients with normal bone tissue, and was respectively higher by 7.1% (p 0.001) and 10.1% (p 0.001), respectively. The overall index in the group with osteopenia was higher and differed from that in the group with osteoporosis by 5.7% (p 0.001).&#x0D; CONCLUSION: The resonance frequency analysis results provide significant information about the state of the implant-bone interface at different treatment stages and during follow-up examinations of patients. The measurement technique makes it possible to observe the dynamics of the osseointegration process, and, if necessary, make timely adjustments to the functional load. Resonance frequency analysis is an important method for documenting the clinical outcome of implantation. This is of particular importance from a medical-legal point of view.

Does hyperbaric oxygen therapy pressure reduce mechanical stability of implants?

Hyperbaric oxygen therapy (HBOT) has beneficial effects for patients complaining of poor bone healing such as related to diabetes mellitus. However, it is known that changing pressure conditions might cause dental barotrauma in the oral cavity. The aim of this study was to evaluate implant mechanical stability under HBOT pressure. Thirty-five implants were placed in bone blocks divided into five groups as control, 1, 3, 5, 7 HBOT cycles. In one cycle, 2.4 bar 100% oxygen pressure was performed. Implants’ stabilities were measured with resonance frequency analysis (RFA) and removal torque (RT) meter device. Data were analyzed using Shapiro Wilk, ANOVA, and Tukey HSD tests for RFA and RT values considering p < 0.05 as the statistical significance level. RFA and RT values were compared by Pearson correlation coefficiency. RFA values of 5 and 7 HBOT cycles were significantly lower than 1, 3 HBOT and control group (p < 0.001). There was no statistical difference between 5 and 7 HBOT cycles RFA values. HBOT pressure simulation slightly but statistically decreased the stability for the implants exposed to 5 and 7 HBOT cycles.Graphical abstract

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

This study evaluated artificial bone models against ahuman bone substitute to assess the primary stability of orthodontic mini-implants (OMIs) at varying implant sites with different morphologies and qualities. Atotal of 1200 OMI placements of four types were inserted into four artificial bone models of different density (D1, D2, D3, D4) and into ahuman bone substitute (HB). The implants varied in diameter (2.0 and 2.3 mm) and length (9and 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. 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 acircular 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). Astrong correlation (r = 0.64) for IPT values and avery strong correlation (r = 0.8) for ISQ values was found between D2 and HB. 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.

Does shelf preparation have efficacy on immediate loading of 4 implants supporting screw-retained full-arch dental prosthesis?

Bone reduction and shelf preparation is a common procedure to establish a new alveolar plane before implant surgery, which might effect the primary stability. Primary stability was questioned in terms of bone reduction and shelf preparation. The suitability of immediate loading was compared between the implants placed on crests, which underwent alveoloplasty, and the implants placed on a naturally healed alveolar bone. We designed and implemented a retrospective cohort study. Twenty patients (mean age 49.2 years) were treated with 160 dental implants. The primary predictor variable was extraction and bone reduction. The secondary predictor variables were bone density and the implant surface. The outcome variables were resonance frequency analysis (RFA) and insertion torque (IT) values. There was no statistically significant difference between groups regarding RFA and IT (P > 0,05). Interactions of surface area with the RFA and IT in both groups were not statistically significant; however, bone density presented a statistically significant effect on outcome variables for both groups. IT and RFA are not influenced by bone reduction, shelf preparation, or the implant surface. Primary stability is mostly affected by bone density in the immediate load of 4 implants to support a full-arch prosthesis.

Photobiomodulation and its Effect on Stability of Orthodontic Mini-implants: A Systematic Review and Meta-analysis of Randomised Controlled Trials

Introduction: The influence of Photobiomodulation (PBM) in the field of orthodontics has been of recent interest. PBM has a promising effect on acceleration of tooth movement, alleviation of pain during orthodontic treatment and Mini-Implant (MI) stability. Aim: The aim of this review was to systematically report on the effectiveness of PBM on the stability of orthodontic MI. Materials and Methods: Literature search was conducted in five electronic databases for human trials published between January 2000 to February 2021 on the effectiveness of PBM therapy for stability of orthodontic MI. This systematic review was conducted during January 2021 and February 2021. Cochrane review manager software (Revman version 5.4) and Cochrane Risk Of Bias (ROB) 2 tool were used for bias assessment. The primary outcome measured was the stability of MI using Resonance Frequency Analysis (RFA) or Periotest Value (PTV). The secondary outcomes measured were pain and inflammation around the peri-implant area. Also, Interleukin-1β (IL-1β) was also measured in gingival crevicular fluid. Results: A total of six Randomized Controlled Trials (RCTs) were included in the review. Out of the 6 studies, 2 showed low Risk Of Bias (ROB) whereas 3 showed some concerns and 1 showed high ROB. Quantitative analysis was done for 4 studies with a random effects model to assess the MI stability measured by periotest at 30 days and 60 days. A significant mean difference of -3.31 (95% CI-5.15,-1.47) between PBM and controls for mini-implant stability at 30 days and a significant mean difference of -3.47 (95% CI-4.58, -2.36) between PBM and controls at 60 days with low heterogeneity was obtained. Three studies reported on the pain response after PBM and both groups showed no significant difference. A decrease in gingival inflammation was reported in one study whereas other study showed no significant change in IL-1ß in gingival crevicular fluid. Conclusion: Majority of the studies included in this review reported improved secondary stability with PBM. The low heterogeneous nature of the quantitative studies also supports the data obtained. However, the results should be concluded with caution.

An In Vitro Analysis on Polyurethane Foam Blocks of the Insertion Torque (IT) Values, Removal Torque Values (RTVs), and Resonance Frequency Analysis (RFA) Values in Tapered and Cylindrical Implants

Background: Several different dental implant microgeometries have been investigated in the literature for use in low-density bone sites. The polyurethane solid rigid blocks represent an optimal in vitro study model for dental implants, because their composition is characterized by symmetrical linear chains of monomers of hexa-methylene sequences producing a self-polymerization process. The aim of the present investigation was to evaluate the primary stability of cylindrical and tapered implants positioned into low-density polyurethane solid rigid blocks. Materials and Methods: Two different macrogeometries, cylindrical (4 mm diameter and 10 mm length) and tapered dental implants (4.20 mm diameter and 10 mm length), were investigated in the present study. The implants were inserted into 10 PCF and 20 PCF polyurethane blocks, with and without an additional cortical layer. The insertion torque (IT) values, the removal torque values (RTVs), and the resonance frequency analysis (RFA) values were measured and recorded. Results: A total of 80 sites were tested, and a significant increased primary stability (PS) was detected in favour of tapered dental implants when compared to cylindrical implants in all experimental conditions (p < 0.05). Higher IT, RT, and RFA values were measured in tapered implants in 10 and 20 PCF polyurethane blocks, both with and without the additional cortical layer. Conclusions: Both implants showed sufficient primary stability in poor density substrates, while, on the other hand, the tapered microgeometry showed characteristics that could also lead to clinical application in low-density posterior maxillary sites, even with a drastically decreased bone cortical component.

Effect of different crown removing procedures on the implant stability quotient and removal torque values of dental implants

Objective: To investigate the effects of different crown-removal methods on the osseointegration of dental implants in implant-retained single crowns. Methods: Two implants were inserted in each tibia of each New Zealand rabbit’s rear legs. After 28 days, resonance frequency analysis was performed on the implants to detect the degree of osseointegration; 24 hours later, the sacrificed tibias were divided into 3 groups according to different crown-removal methods: crown removal with a diamond bur, the use of a spring-loaded crown remover, and the use of a pneumatic crown remover. Following the crown-removal procedures, the implants’ resonance frequency analysis values and removal torque values were measured. Results: No significant difference in implant stability quotient was measured after crown removal for either group of diamond bur or group of pneumatic crown remover (p=0.677 and p=0.918, respectively). However, there was a statistically significant difference in implant stability quotient after crown removal for group of spring-loaded crown remover (p=0.008). Moreover, no significant difference was detected between the groups’ removal torque values (p&amp;gt;0.05). Conclusion: The crown-removal procedure has significantly unfavorable effect on the implant stability quotient values of the implants, whereas removal torque values of the implants was not affected crown-removal procedures.