Mandibular overdentures retained by 1 or 2 implants: a 5-year randomized clinical trial on implant stability and peri-implant outcomes.

AIM: This is a report of the 5-year results of a two-group parallel randomized clinical trial comparing longitudinal implant stability, and clinical and radiographic peri-implant outcomes of mandibular overdentures retained by one (1-IOD group) or two (2-IOD group) implants. METHODS: All participants received 4.1 mm diameter tissue-level implants (Straumann® Standard Plus - SLActive®, Institut Straumann AG), installed in the mandible midline (1-IOD; n = 23) or the lateral incisor-canine area bilaterally (2-IOD; n = 24), and loaded after 3 weeks. Implant Stability Quotient (ISQ) was measured using a resonance frequency device (Osstell® Mentor, Integration Diagnostics) at implant placement, after three weeks (loading), and at the 6-month, 1-, 3-, and 5-year follow-ups. Marginal bone loss and clinical implant outcomes (plaque, calculus, suppuration and bleeding) were assessed periodically up to 5 years after loading. RESULTS: Only minor changes in marginal bone level were observed after 5 years (mean = 0.37; SD = 0.44 mm), and satisfactory and stable peri-implant parameters were observed throughout the 5-year follow-up. No significant differences between groups were found. Overall, the mean primary implant stability was considered high (> 70) for the two groups (1-IOD = 78.1 ± 4.5; 2-IOD = 78.0 ± 5.8). No noticeable changes were observed between implant insertion and loading. A marked increase was observed from insertion to the 6-month follow-up - the mean difference for the 1-IOD group was + 5.5 ± 5.5 (Effect size = 1.00), while for the 2-IOD group, the mean difference was + 6.0 ± 5.6 (Effect size = 1.08). No relevant changes were observed throughout the follow-up periods up to 5 years. Linear mixed-effect model regression showed no influence of the bone-related variables (p > 0.05) and the number of implants (p = 0.087), and a significant effect of the time variable (p < 0.001). CONCLUSION: Satisfactory peri-implant outcomes and stable secondary stability suggest good clinical performance and successful long-term osseointegration of the implants for single and two-implant mandibular overdentures. Using a single implant to retain a mandibular overdenture does not seem to result in detrimental implant loading over the five years of overdenture use. CLINICAL RELEVANCE: This study corroborates the use of a single implant to retain a mandibular denture.

Influence of torque and bone type on stability quotient of two implant platforms: a clinical trial.

The objective of this study was to analyze the influence of insertion torque, bone type, and peri-implant bone loss on implant stability quotient (ISQ) of cylindrical external hexagon (EH) and Morse Taper (MT) implants. Forty-four single implants were placed in the edentulous areas of 20 patients who met the inclusion and exclusion criteria. Immediately after implant placement (t1) and after osseointegration (four and six months for mandible and maxilla, respectively) (t2), insertion torque, resonance frequency, and peri-implant bone loss were measured using probing depths and digital periapical radiography. A significant difference was noted in the ISQ values between t1 and t2 in type III bone for EH and MT implants. No significant difference in bone loss values was observed when comparing bone types for EH or MT in all evaluated sites. Based on marginal bone loss assessed using radiography, there was no significant difference between the MT and EH groups. A positive correlation between torque and ISQ t1 value was observed for MT (correlation: 0.439; p = 0.041) and EH (correlation: 0.461; p = 0.031) implants. For EH and MT implants, the greater the insertion torque, the greater was the ISQ value (moderately positive correlation). A weak negative correlation was found between bone type and ISQ t1 for MT implants. Contrarily, no correlation was observed between bone type and ISQ t1 for EH implants. In all cases, bone loss around the implants was clinically normal.

Resonance Frequency Analysis Identifies Implant- and Host-Related Factors Associated With Bone-Anchored Hearing Implant Stability.

HYPOTHESIS: Resonance frequency analysis (RFA) is a reliable, noninvasive method to assess the stability of bone-anchored hearing implants (BAHIs), although surgical-, implant-, and host-related factors can affect its outcome. BACKGROUND: BAHI plays an important role in restoring hearing function. However, implant- and host-related factors contribute to premature implant extrusion. To mitigate this, noninvasive methods to assess implant stability, along with a better understanding of factors contributing to BAHI failure, are needed. METHODS: We evaluated the utility of RFA to quantify implant stability in sawbone (bone mimicking material), 29 human cadaveric samples, and a prospective cohort of 29 pediatric and 27 adult participants, and identified factors associated with implant stability. To validate the use of RFA in BAHI, we compared RFA-derived implant stability quotient (ISQ) estimates to peak loads obtained from mechanical push-out testing. RESULTS: ISQ and peak loads were significantly correlated (Spearman rho = 0.48, p = 0.0088), and ISQ reliably predicted peak load up to 1 kN. We then showed that in cadaveric samples, abutment length, internal table bone volume, and donor age were significantly associated with implant stability. We validated findings in our prospective patient cohort and showed that minimally invasive Ponto surgery (MIPS; versus linear incision), longer implantation durations (>16 wk), older age (>25 yr), and shorter abutment lengths (≤10 mm) were associated with better implant stability. Finally, we characterized the short-term reproducibility of ISQ measurements in sawbone and patient implants. CONCLUSIONS: Together, our findings support the use of ISQ as a measure of implant stability and emphasize important considerations that impact implant stability, including surgical method, implant duration, age, and abutment lengths.

Thermal implant removal in a pig jaw: a proof of concept study.

OBJECTIVES: The aim of this study was to evaluate whether thermal implant removal of osseointegrated implants is possible using a diode laser with an specific temperature-time interval. MATERIALS AND METHODS: First, tooth extraction of the first three premolars was performed in the maxilla and mandible on both sides of 10 pig. After 3 months, implants were inserted into the upper and lower jaws of 10 pigs. After 3 more months, osseointegrated implants were heated with a laser device to a temperature of 50 °C for 1 min. After 14 days, the implant stability quotient (ISQ), torque-out values, and bone-to-implant contact (BIC) ratio were assessed using resonance frequency analysis. RESULTS: ISQ values showed no significant differences within each group or between the control and test groups. Furthermore, torque-out and BIC value measurements presented no significant differences between the groups. CONCLUSIONS: At 50°C, changes in the BIC values were noticeably smaller; however, these differences were not significant. Future studies should evaluate the same procedures at either a higher temperature or longer intervals. CLINICAL RELEVANCE: With only 50 °C for 1 min, a dental implant will not de-integrate predictably.

Correlation of two different devices for the evaluation of primary implant stability depending on dental implant length and bone density: An in vitro study.

Non-invasive objective implant stability measurements are needed to determine the appropriate timing of prosthetic fitting after implant placement. We compared the early implant stability results obtained using resonance frequency analysis (RFA) and damping capacity analysis (DCA) depending on the implant length and bone density. Total 60, 4.0 mm diameter implants of various lengths (7.3 mm, 10 mm, and 13 mm) were used. In Group I, low-density bone was described using 15 PCF (0.24 g/cm3) polyurethane bone blocks, and in Group II, 30 PCF (0.48 g/cm3) polyurethane bone blocks were used to describe medium density bone. RFA was performed using an Osstell® Beacon+; DCA was performed using Anycheck®. Measurements were repeated five times for each implant. Statistical significance was set at P <0.05. In Group I, bone density and primary implant stability were positively correlated, while implant length and primary implant stability were positively correlated. In Group II, the implant stability quotient (ISQ) and implant stability test (IST) values in did not change significantly above a certain length. Primary implant stability was positively correlated with bone density and improved with increasing implant length at low bone densities. Compared with the Osstell® Beacon+, the simplicity of Anycheck® was easy to use and accessible.

ISQ as a Diagnostic Tool in Implants Affected with Bone Loss: An In Vitro Experimental Study.

PURPOSE: To determine the relationship between bone loss that occurs during the peri-implantitis process and variations in implant stability using resonance frequency analysis (RFA) measurement methods. MATERIALS AND METHODS: Forty selftapping implants were placed in cow ribs, and study scenarios were established according to the affected implant side and bone loss depth (n = 10 implants per group): Case 1 = bone loss on one side (vestibular); Case 2 = bone loss on two opposite sides (buccal and lingual); Case 3 = bone loss on two adjacent sides (buccal and mesial); and Case 4 = foursided bone loss (circumferential). For each group of 10 implants, first a bone loss of 0 mm was evaluated, then 4-mm defects (simulating 1/3 of bone loss) were created and evaluated, and finally 8-mm defects (simulating 2/3 of bone loss) were created and evaluated. Osteotomy measurements were made with a periodontal probe. For each implant, RFA was measured by the same operator using the Beacon system (Osstell). RESULTS: The initial implant stability quotient (ISQ) values of the 40 implants exceeded 70, reflecting an average of 73 in the buccolingual (VL) and 74.8 in the mesiodistal (MD) directions. ISQ measurements in the 10 implants in which bone dehiscence was performed on the vestibular aspect reflected a decrease in ISQ values as bone loss increased. When generating bone loss in two opposite sides (buccal and lingual), a greater decrease in ISQ values was observed when 2/3 of the implant were affected. The average VL ISQ measurement was less than 70 when at sites with 2/3 of bone loss. CONCLUSIONS: When bone loss occurs on only one side of the implant, the ISQ values decrease, but the implant maintains good stability. The same occurs when two opposite sides of the implant are affected, as the unaffected side has the least decrease in ISQ value.

A Comprehensive Study on Implant Stability Quotient (ISQ) in View of Resonance Frequency and Spectrum Analysis.

PURPOSE: To investigate how well an implant stability quotient (ISQ) represents resonance frequency. MATERIALS AND METHODS: Benchtop experiments on standardized samples that replicated a mandibular premolar site were conducted to correlate an ISQ value and a resonance frequency to synthetic bone density and an incremental insertion torque; then, a frequency spectrum analysis was performed to check the validity of the resonance frequency analysis (RFA). Brånemark Mk III implants (4 × 11.5 mm; Nobel Biocare) were placed in Sawbones test models of five different densities (40, 30, 40/20, 20, and 15 PCF). An incremental insertion torque was recorded during implant placement. To perform stability measurements, the test models were partially clamped in a vise (unclamped volume: 10 × 20 × 34 mm). A MulTipeg (Integration Diagnostics) was attached to the implants, and a Penguin (Integration Diagnostics) RFA measured ISQ. Simultaneously, the MulTipeg motion was monitored via a laser Doppler vibrometer and processed by a spectrum analyzer to obtain the resonance frequency. Tightness of the clamp was adjusted to vary the resonance frequency. A statistical analysis produced a linear correlation coefficient (R) among the measured ISQ, resonance frequency, and incremental insertion torque. RESULTS: The resonance frequency had high correlation to the incremental insertion torque (R = 0.978), confirming the validity of using RFA for this study. Measured ISQ data were scattered and had low correlation to the resonance frequency (R = 0.214) and the incremental insertion torque (R = 0.386). The spectrum analysis revealed the simultaneous presence of multiple resonance frequencies. CONCLUSIONS: For the designed benchtop tests, resonance frequency does indicate implant stability in view of Sawbones density and incremental insertion torque. However, ISQ measurements do not correlate to the resonance frequency and may not reflect the stability when multiple resonance frequencies are present simultaneously.

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.

Is Acoustic modal analysis a reliable substitution for Osstell® device in dental implant stability assessment? An experimental and finite element analysis study.

BACKGROUND: Different methods have been proposed to investigate the fixation stability of dental implants, each of which has its limitations. Among these methods, resonance frequency analysis (RFA) has been widely utilized to measure dental implant stability. This study aimed to assess dental implants with two non-destructive RFA and acoustic modal analysis (AMA) validated with a finite element simulation of the fundamental natural frequency (NF) of the bone analog-implant structure. MATERIAL AND METHODS: A total number of 18 implants were inserted into two Polyurethane (PU) bone blocks with different densities (0.16 g/cc and 0.32 g/cc). AMA was used to measure NF; First, the sound originating from the axial tapping of the implant was recorded with a simple microphone. Secondly, a fast Fourier transformation algorithm was conducted to determine the NF of the implant-bone analog structure. In parallel, the ISQ (Implant Stability Quotient) value was measured using the Osstell® device. Finally, using finite element analysis (FEA), the implant-bone analog structure was modeled for validation. RESULTS: Doubling the bone analog density resulted in an average increase of 82% and 47% in the NF and ISQ using AMA and Osstell®, respectively (P-value<0.05). Furthermore, a strong linear relationship (R2= 0.93) was observed between the measured NF and ISQ values in the linear regression analysis. The NF of the dental implant predicted by FEA was overestimated by about 15.2% and 15.0% than those in the low- and high-density PUs, respectively. Moreover, the FEA predicted an increase of 83% in NF by increasing the bone analog density from 0.16 to 0.32 g/cc. CONCLUSIONS: Having required the minimum process combined with easily available equipment makes it an ideal method for fixation strength studies. The good correspondence between the ISQ values and NFs, in addition to the good accuracy and reliability of the later method, confirms its application for fixation stability assessment.

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

OBJECTIVES: This in vitro study is aimed at assessing whether implant primary stability is influenced by implant length in artificial bone with varying densities. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. CLINICAL RELEVANCE: Therefore, our data offer valuable insights into the biomechanical behavior of these implants, which could be clinically beneficial for enhancing surgical planning.

Effects of Implant Diameter on Implant Stability and Osseointegration in the Early Stage in a Dog Model.

Purpose: To determine the optimal implant diameter under limited bone width by comparing the effects of implants with different diameters on implant stability, peri-implant bone stability, and osseointegration. In addition, to evaluate the reliability of resonance frequency analysis (RFA) in detecting osseointegration and marginal bone level (MBL). Materials and Methods: Mandibular premolars and first molars of seven beagle dogs were extracted. After 8 weeks, their mandibular models and radiographic information were collected to fabricate implant templates. Implant sites were randomly divided into three groups according to diameter: Ø3.3, Ø4.1, and Ø4.8 mm. Implant stability quotient (ISQ) measurement and radiographic evaluation were performed after surgery (baseline) and at 4, 8, and 12 weeks. Three dogs were euthanized at 4 weeks to observe osteogenesis and implant-tissue interface biology. Four dogs were euthanized at 12 weeks to observe osseointegration. Hard tissue sections were prepared to analyze osteogenesis (fluorescence double labeling) and osseointegration (methylene blue-acid fuchsin staining). Results: At baseline and at 4, 8, and 12 weeks, the ISQ values of Ø4.1- and Ø4.8-mm implants did not differ (P > .05), but both had higher values than the Ø3.3-mm implants (P < .05). The mean marginal bone resorption (MBR) associated with Ø3.3-, Ø4.1-, and Ø4.8-mm implants was 0.65 ± 0.58 mm, 0.37 ± 0.28 mm, and 0.73 ± 0.37 mm, respectively. The buccal MBR of Ø4.8-mm implants was significantly higher than that of Ø4.1-mm implants (P < .05). The bone-to-implant contact (BIC) percentage at 12 weeks did not differ for any group (P > .05). The correlation coefficients between the ISQ and MBL of the Ø3.3-, Ø4.1-, and Ø4.8-mm implants were -0.84 (P < .01), -0.90 (P < .001), and -0.93 (P < .001), respectively, while that between the ISQ and BIC was 0.15 (P > .05). Conclusions: During the early healing stage, the performance of Ø4.1- and Ø4.8-mm implants in terms of implant stability was better than that of Ø3.3-mm implants. Implant diameter may not influence BIC percentage. RFA can be used to evaluate implant stability and MBL but is not suitable to assess the degree of osseointegration.

Resonance Frequency Analysis to Assess the Stability of Immediate Implants: A Retrospective Clinical Trial.

Adequate implant primary stability is a key factor to obtain osseointegration and can be measured at insertion by insertion torque (IT) and at different timepoints with resonance frequency analysis (RFA), expressed as an implant stability quotient (ISQ). This retrospective study investigated the correlation between ISQ and IT at implant insertion. All patients who were eligible for this single-cohort retrospective clinical trial were treated with an immediate implant. IT parameters were recorded at implant insertion, and ISQ values were recorded at insertion and at 2-, 4-, and 12-month follow-ups. The study comprised 23 patients who received 32 implants. The mean IT value was 46.87 ± 9.66 Ncm (range: 25 to 65 Ncm), and the mean ISQ value at implant insertion was 71.45 ± 4.24 (range: 63 to 78); these values showed a statistically significant correlation (P < .0001). According to the present data and considering the implant design used in this trial, there is a statistically significant and positive correlation between IT and ISQ values. Thus, ISQ can be used as a reliable method to measure implant stability over time.

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.

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.

Influence of different surgical techniques on primary implant stability in the posterior maxilla: a randomized controlled clinical trial.

BACKGROUND AND OBJECTIVE: Primary stability (PS) is remarkable for secondary stability and implant success. Surgical technique modifications seem to improve primary stability, especially in poor quality bone. The aim of this study was to compare the insertion torque (IT) and implant stability quotients (ISQ) of implants placed with underpreparation, expanders, and standard surgical instrumentation in different bone types. MATERIAL AND METHODS: This randomized controlled clinical trial enrolled 108 patients (n=108 implants) distributed in three study groups: group 1 (n=36) underpreparation technique, group 2 (n=36) expander technique, and group 3 (n=36) conventional drilling. IT was recorded with a torque indicator. ISQ was recorded with resonance frequency analysis immediately after surgery. RESULTS: ISQ values were associated with the patient's bone quality and were higher in bone quality type II (76.65) and type III (73.60) and lower in bone quality type IV (67.34), with statistically significant differences (p<0.0001). Lower stability results were obtained when conventional drilling (69.31) was used compared to the use of underpreparation (74.29) or expanders (73.99) with a level of significance of p=0.008 and p=0.005, respectively. CONCLUSIONS: The surgical technique influences the PS when there is low-quality bone. In low-quality bones, conventional drilling obtains lower ISQ values. CLINICAL RELEVANCE: Replace the conventional drilling technique for an alternative, underpreparation or expanders, in low-quality bone in order to achieve greater primary stability.

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.

Influence of implant macro-designs on primary and secondary implant stability / Influencia de los macrodiseños de implantes en la estabilidad primaria y secundaria del implante

Introduction: Tapered implants have shown that thanks to their macro design they are capable of expanding the surgical bed performed by the surgeon, which in clinical practice gives a feeling of greater stability, however it is highly subjective and dependent on the operator. Aim: To analyze the influence of the implant macro design in the primary and secondary stability by means of analysis of resonance frequency and force of insertion. Methods: 38 Screw Type and Tapered Type implants were placed in 18 patients in the Bucomaxillofacial Implantology program of the University of Chile during 2006 and 2007 in type II or III bone jaws according to Leckholm and Zarb. Implant stability, implant stability coefficient (ISQ), was measured through Ostell® mentor at the time of installation (ISQ1) and then at connection (ISQ2) and the Insertion Torque through the Osseoset® machine: 17 Screw Type implants with an approximate average contact area of 237 mm2 (3.75/15 mm; 3.75/13 mm) and 17 Tapered Type implants with an approximate average contact area of 226 mm2 (4.3/13 mm; 4.3/16 mm). Results: The averages of ISQ1 and ISQ2 and Insertion Torque respectively for implants with an approximate contact area of 237 mm2 were 71.3 ISQ1, 66.6 ISQ2 and 44.52 Ncm; for 226 mm2 implants it was 75 ISQ1, 72.5 ISQ2 and 48.82 Ncm. Conclusion: Implants with an average contact area of approximately 226 mm2 (Tapered Type) present significantly higher primary and secondary stability than those with an average contact area of approximately 237 mm2 (Screw Type). (Average ISQ1: p = 0.0473; Insertion Torque: p = 0.0031 and Average ISQ2: p = 0.0039)(AU)

Introducción: Los implantes Cónicos han demostrado que gracias a su macro diseño son capaces de expandir el lecho quirúrgico realizado por el cirujano, lo que en la práctica clínica da una sensación de mayor estabilidad, sin embargo, ella es altamente subjetiva y dependiente del operador. Objetivo: Analizar la influencia del diseño del implante en la estabilidad primaria y secundaria mediante análisis de frecuencia de resonancia y Torque de Inserción. Métodos: 38 implantes Tipo Tornillo y Tipo Cónico fueron colocados en 18 pacientes en el programa de Implantología Bucomáxilofacial de la Universidad de Chile durante el año 2006 y 2007 en maxilares de hueso tipo II o III según Leckholm y Zarb. Se midió la estabilidad implantaria, coeficiente de estabilidad del implante (ISQ), a través de Ostell® mentor al momento de la instalación (ISQ1) y luego en la conexión (ISQ2) y el Torque de Inserción a través de el motor Osseoset®: 17 implantes Tipo Tornillo de área de contacto promedio aproximada de 237 mm2 (3.75/15 mm; 3.75/13 mm) y 17 implantes Tipo Cónico de área de contacto promedio aproximada de 226 mm2 (4.3/13 mm; 4.3/16 mm). Resultados: Los promedios de ISQ1 e ISQ2 y Torque de Inserción respectivamente para implantes de área contacto aproximada de 237 mm2 fue de 71,3 ISQ1, 66,6 ISQ2 y 44,52 Ncm; para implantes de 226 mm2 fue de 75 ISQ1, 72,5 ISQ2 y 48,82 Ncm. Conclusión: Los implantes de área contacto promedio aproximada de 226 mm2 (Tipo Cónicos) presentan estabilidad primaria y secundaria significativamente mayor a los de área contacto promedio aproximada de 237 mm2 (Tipo Tornillo). (Promedio ISQ1: p = 0.0473; Torque de Inserción: p = 0.0031 y Promedio ISQ2: p = 0.0039)(AU)

The Effects of Injectable Platelet-Rich Fibrin on Implant Stability.

PURPOSE: To investigate the effects of injectable platelet-rich fibrin (i-PRF) on implant stability. MATERIALS AND METHODS: A total of 40 implants (BEGO Semados RS/RSX implants, BEGO Implant System) were surgically placed in 15 patients between the ages of 25 and 67 years who had mandibular edentulous areas. After the implant sockets were prepared with the appropriate protocol, i-PRF was applied to the implant surface and socket with the help of a 5-cc sterile syringe in the study group, and implants were placed without i-PRF in the control group. In the research process, the resonance frequency analysis (RFA) method was used to measure implant stability. The implant stability quotient (ISQ) values were determined during the time of the operation and at the first, second, and fourth weeks. RESULTS: The results obtained after the stability measurement periods showed that the decrease in the mean ISQ values in the control group was statistically significant in the first week. Evaluations made in the following weeks were not statistically significant. The study group showed an increase in ISQ values during the measurement periods, and the increases in the second and fourth weeks were statistically significant. CONCLUSION: I-PRF had positive effects on early implant stability, and i-PRF can be safely used in dental implant surgery and promotes bone healing around dental implants.

Resonance Frequency Analysis to Evaluate the Effect of Different Drilling Techniques on Implant Stability at Different Time Intervals: A Randomized Clinical Trial.

PURPOSE: To evaluate the effect of different drilling techniques on implant stability at different time intervals. MATERIALS AND METHODS: Patients were randomly allotted into three groups based on drilling technique for osteotomy: conventional drilling technique; simplified drilling technique; or modified conventional drilling technique. In 30 patients (n = 10 each group), a total of 44 implants were placed. In the conventional drilling technique, drills with increasing diameters were used. In the simplified drilling technique, only pilot and final-diameter drills were used. In the modified conventional drilling technique, all the drills were used in sequential order in the clockwise direction except the last drill, which was used in the counterclockwise direction. Implant stability quotient was recorded immediately after placing implants and at 1 and 3 months. Statistical analysis was performed with two-way analysis of variance (ANOVA) and Student t test. RESULTS: Two-way ANOVA showed that drilling technique (P < .001) and time (P = .002) did have a statistically significant effect on implant stability quotient. The modified conventional drilling technique showed a drop in secondary implant stability at 1 month that was negligible compared to the other techniques. After 1 month, there was a significant increase in implant stability quotient with the modified conventional drilling technique compared to the conventional drilling technique (P = .001). The least crestal bone loss during 3 months of follow-up was with the modified conventional drilling technique (0.37 ± 0.06). CONCLUSION: Secondary stability increased with the modified conventional drilling technique in 3 months and showed a negligible drop at 1 month. This novel drilling technique had an early shift from a decrease to an increase in stability pattern, along with the least crestal bone loss at 3 months.

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.