The significance and parameter standards of the implant primary stability / 口腔疾病防治

@#The nature, significance, parameters, influencing factors and testing of implant primary stability were studied by a literature review. Primary stability is a kind of anchorage force at the interface between the implant and bone, and it is merely mechanical. The significance of primary stability is to keep the implant unmovable so that the new bone can grow undisturbed on the surface of the implant without interference from fibrous tissue. The implant is finally bound to the bone by osseointegration. The most common assessments of primary stability are insertion torque (IT), the implant stability quotient (ISQ) of the resonance frequency analysis (RFA) and Periotest. IT is more commonly used to directly imply initial stability. At present, no consensus has been reached regarding the concrete parameters of primary stability to predict osseointegration. Implant osseointegration could be developed through all phases of primary stability. However, the excessive primary stability would cause mini-bone fractures, followed by bone necrosis at the interface and the final failure of implantation. Primary stability is influenced by three factors: implant design, bone condition of alveolar bone, and surgical technique. Under the condition of a lack of primary stability and immediate implantation, there may be the possibility of successful osseointegration. Therefore, it is necessary to re-examine the accuracy of the current elaboration on the primary stability. It is related directly to whether the clinic can choose the appropriate implant treatment path.

The evaluation of implant stability measured by resonance frequency analysis in different bone types

OBJECTIVES: Bone density seems to be an important factor affecting implant stability. The relationship between bone density and primary and secondary stability remains under debate. The aim of this study was to compare primary and secondary stability measured by resonance frequency analysis (RFA) between different bone types and to compare implant stability at different time points during 3 months of follow-up. MATERIALS AND METHODS: Our study included 65 implants (BioHorizons Implant Systems) with 3.8 or 4.6 mm diameter and 9 or 10.5 mm length in 59 patients. Bone quality was assessed by Lekholm-Zarb classification. After implant insertion, stability was measured by an Osstell device using RFA at three follow-up visits (immediately, 1 month, and 3 months after implant insertion). ANOVA test was used to compare primary and secondary stability between different bone types and between the three time points for each density type. RESULTS: There were 9 patients in type I, 18 patients in type II, 20 patients in type III, and 12 patients in type IV. Three implants failed, 1 in type I and 2 in type IV. Stability values decreased in the first month but increased during the following two months in all bone types. Statistical analysis showed no significant difference between RFA values of different bone types at each follow-up or between stability values of each bone type at different time points. CONCLUSION: According to our results, implant stability was not affected by bone density. It is difficult to reach a certain conclusion about the effect of bone density on implant stability as stability is affected by numerous factors.

Evaluation of the stability of sandblasted, large-grit, acid-etched implants with tapered straight body design

PURPOSE: Implant surface modification and implant design are the principle targets for achieving successful primary stability. The aim of this study was to measure implant stability quotient (ISQ) values of sandblasted, large-grit, acid-etched (SLA) implants with tapered straight body design during the healing period, and to determine the various factors affecting implant stability. MATERIALS AND METHODS: To measure implant stability, resonance frequency analysis (RFA) was performed in 26 patients (13 women and 13 men) with 44 SLA implants with tapered straight body design. Implant stability (ISQ values) was evaluated at baseline and healing abutment connection (12 weeks), and the correlations between RFA and insertion torque (IT), bone quality, and jawbone were determined. RESULTS: The mean ISQ value of the implants was 69.4 ± 10.2 at the time of implant placement (baseline) and 81.4 ± 6.9 at the time of healing abutment connection (P 0.05). CONCLUSION: ISQ values of SLA implants with tapered straight body design were high at baseline and healing abutment connection. It was concluded that SLA implants with tapered straight body design show improved primary and secondary stability, and that immediate or early loading may be applicable.

Effect of osseointegration in the posterior area by Shenggu pills / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aimed to investigate the osseointegration condition by measuring the implant stability quotient (ISQ) to study the effect of osseointegration in the posterior area by Shenggu pills.</p><p><b>METHODS</b>A total of 101 DENTIUM implants were placed in 48 patients. Fifty implants placed in 24 patients were addressed as usual, whereas 51 implants placed in 24 patients were treated with Shenggu pills. ISQ was tested on the day of surgery and consecutively at 4, 8, and 12 weeks. All data were analyzed.</p><p><b>RESULTS</b>The efficacy of the treatment group was no much better than that of control group on the day of surgery and consecutively at 12 weeks with no significant difference (P>0.05). The efficacy of the treatment group was significantly better than that of the control group at 4 and 8 weeks (P<0.05). The implants placed in the mandible were significantly better than those placed in the maxilla (P<0.05).</p><p><b>CONCLUSIONS</b>Early intake of Shenggu pills could accelerate the implant bone union, improve the implants' ISQ, and ensure the success rate of the operation.</p>

Is there a difference in the resonance frequency values obtained directly on the implants and abutments? / ¿Existe diferencia en la frecuencia de resonancia obtenida directamente en los implantes y pilares?

The aim was to evaluate the differences of implant stability quotient (ISQ) between implants with external hexagon and Morse taper connectors. The study had a split mouth design, composed by 10 patients who received hybrid protocol prosthesis. In total, 40 implants (3.75 x 13 mm) were installed: on the right side, 20 external hexagon, and on the left, 20 Morse taper. After two years in function, the stability test was applied by using the MRI machine Osstell ISQ directly on the implants and on the abutments. Considering the measurements made on the implants, there were differences between HE and CM mesial (p= 0.011), lingual (p= 0.003) and distal (p= 0.006). Considering the measurements made on the abutments, there were differences between HE and CM on the buccal (p= 0.020) and lingual (p= 0.004). The trend and higher values are for the CM group. The values for Morse taper implants were always higher in a statistically significant manner, when compared to the external hexagon.

El objetivo fue evaluar las diferencias del coeficiente de estabilidad de implantes comparando los de conexión de hexágono externo (HE) y cono morse (CM). El estudio tuvo un diseño de boca dividida, siendo compuesta por 10 pacientes que recibieron protocolos protésicos de tipo hibrido. En total, 40 implantes (3,75x13 mm) fueron instalados: en el lado derecho, 20 implantes de hexágono externo y en el lado izquierdo, 20 implantes de cono morse. Después de dos años en función, la prueba de estabilidad fue aplicada utilizando una maquina MRI, Ostell ISQ directamente sobre los implantes y pilares. Considerando las medidas en los implantes, hubo diferencias entre los implantes HE y CM en mesial (p= 0,011), lingual (p= 0,003) y distal (p= 0,006). Considerando las medidas en los pilares, hubo diferenciasentre HE y CM en el sector bucal (p= 0,020) y lingual (p= 0,004). Los valores mas altos se obtuvieron en CM; los valores de las conexión tipo cono morse presentaron mayor estabilidad al comparase con los implantes de conexión de hexágono externo.

Combined effects of rhBMP-2 and rhVEGF coated onto implants on osseointegration: pilot study / 대한치과보철학회지

PURPOSE: The present study is aimed to evaluate the combined effect of recombinant human bone morphogenetic protein 2 (rhBMP-2) and recombinant human vascular endothelial growth factor (rhVEGF) coated onto anodized implants on osseointeration. MATERIALS AND METHODS: Six New Zealand white rabbit were used in this study. Each animal received 4 implants that were either coated with rhBMP-2 and rhVEGF (Study group) or anodized implant (Control group) in both tibia. This was performed using a randomized split-mouth design. A total 24 implants were used. The implant stability quotient (ISQ) value using resonance frequency analyser and removal torque (RTQ) measurement were investigated at 2 and 8 weeks. The t-test was used for statistical analysis (alpha=.05). RESULTS: Control and study group showed good osseointegration at 8 weeks. The ISQ and RTQ values of study group were significant compared with the control group at 8 weeks (P.05). CONCLUSION: It was concluded that rhBMP-2 with rhVEGF coated onto anodized implants can induce better osseointegration at late healing period.

The influence of implant diameter, length and design changes on implant stability quotient (ISQ) value in artificial bone / 대한치과보철학회지

PURPOSE: The purpose of this study is to ascertain the stability of the implant by comparing the effects of the change of implant diameter, length and design on implant stability quotient. MATERIALS AND METHODS: To remove the variable due to the difference of bone quality, the uniform density (0.48 g/cm3) Polyuretane foam blocks (Sawbones(R), Pacific Research Laboratories Inc, Vashon, Washington) were used. Implants (Implantium(R), Dentium, Seoul, Korea) were placed with varying diameters (phi3.8, phi4.3 and phi4.8) and length (8 mm, 10 mm and 12 mm), to assess the effect on implant stability index (ISQ). Also the influence of the design of the submerged and the non-submerged (SimplelineII(R), Dentium, Seoul, Korea) on ISQ was evaluated. To exclude the influence of insertion torque, a total of 60 implants (n = 10) were placed with same torque to 35 N. Using Osstell(TM) mentor (Integration Diagnostic AB, Sweden) ISQ values were recorded after measuring the resonant frequency, one-way ANOVA and Tukey HSD test results were analyzed. (alpha=0.05). RESULTS: 1. The change of the diameter of the implant did not affect the ISQ (P>.05), but the increase of implant length increased the ISQ(P<.001). 2. The change in implant design were correlated with the ISQ, and the ISQ of submerged design was significantly higher than that of the non-submerged design(P<.05). CONCLUSION: In order to increase implant stability, the longer implant is better to be selected, and on the same length of implant, submerged design is thought to be able to get a higher ISQ than the non-submerged.

Resonance frequency analysis.

Initial stability at the placement and development of osseointegration are two major issues for implant survival. Implant stability is a mechanical phenomenon which is related to the local bone quality and quantity, type of implant, and placement technique used. The application of a simple, clinically applicable, non-invasive test to assess implant stability and osseointegration is considered highly desirable. Resonance frequency analysis (RFA) is one of such techniques which is most frequently used now days. The aim of this paper was to review and analyze critically the current available literature in the field of RFA, and to also discuss based on scientific evidence, the prognostic value of RFA to detect implants at risk of failure. A search was made using the PubMed database to find all the literature published on "Resonance frequency analysis for implant stability" till date. Articles discussed in vivo or in vitro studies comparing RFA with other methods of implant stability measurement and articles discussing its reliability were thoroughly reviewed and discussed. A limited number of clinical reports were found. Various studies have demonstrated the feasibility and predictability of the technique. However, most of these articles are based on retrospective data or uncontrolled cases. Randomized, prospective, parallel-armed longitudinal human trials are based on short-term results and long-term follow up are still scarce in this field. Nonetheless, from available literature, it may be concluded that RFA technique evaluates implant stability as a function of stiffness of the implant bone interface and is influenced by factors such as bone type, exposed implant height above the alveolar crest. Resonance frequency analysis could serve as a non-invasive diagnostic tool for detecting the implant stability of dental implants during the healing stages and in subsequent routine follow up care after treatment. Future studies, preferably randomized, prospective longitudinal studies are certainly needed to establish threshold ranges for implant stability and for implants at risk for losing stability for different implant system.

Effect of bone quality and implant surgical technique on implant stability quotient (ISQ) value

PURPOSE: This study investigated the influence of bone quality and surgical technique on the implant stability quotient (ISQ) value. In addition, the influence of interfacial bone quality, directly surrounding the implant fixture, on the resonance frequency of the structure was also evaluated by the finite element analysis. MATERIALS AND METHODS: Two different types of bone (type 1 and type 2) were extracted and trimmed from pig rib bone. In each type of bone, the same implants were installed in three different ways: (1) Compaction, (2) Self-tapping, and (3) Tapping. The ISQ value was measured and analyzed to evaluate the influence of bone quality and surgical technique on the implant primary stability. For finite element analysis, a three dimensional implant fixture-bone structure was designed and the fundamental resonance frequency of the structure was measured with three different density of interfacial bone surrounding the implant fixture. RESULTS: In each group, the ISQ values were higher in type 1 bone than those in type 2 bone. Among three different insertion methods, the Tapping group showed the lowest ISQ value in both type 1 and type 2 bones. In both bone types, the Compaction groups showed slightly higher mean ISQ values than the Self-tapping groups, but the differences were not statistically significant. Increased interfacial bone density raised the resonance frequency value in the finite element analysis. CONCLUSION: Both bone quality and surgical technique have influence on the implant primary stability, and resonance frequency has a positive relation with the density of implant fixture-surrounding bone.

The study of bone density assessment on dental implant sites

INTRODUCTION: Bone density is one of the important factors for the long term success of endosseous implants. The bone density varies from site to site and from patient to patient. A preoperative evaluation of the bone density is quite useful to oral surgeons for planning dental implantation. More accurate information on the bone density will help surgeons identify suitable implant sites, thereby increase the success rate of dental implantation. This study examined the correlation between the bone density measured preoperatively by computed tomography (CT) and the implant primary stability measured by resonance frequency analysis. Furthermore, the effects of the implant sites, gender, age and generalized systemic disorder patients on the bone density and primary implant stability were examined. MATERIALS AND METHODS: One hundred and fourteen patients were selected. None of the patients had undergone a tooth extraction or bone graft history in the previous year. Preoperatively, the patients underwent CT scanning to evaluate the Hounsfield unit (HU), and resonance frequency analysis (RFA) was used to evaluate the implant primary stability at the time of implant installation. All implants were 4.0 mm diameter and 11.5 mm length US II. All patients were recorded and the HU and implant stability quotient (ISQ) value were evaluated according to the sites, gender and age. RESULTS: The highest HU values were found in the mandibular anterior site (827.6+/-151.4), followed by the mandibular molar site (797+/-135.1), mandibular premolar site (753.8+/-171.2), maxillary anterior site (726.3+/-154.4), maxillary premolar site (656.7+/-173.8) and maxillary molar site (621.5+/-164.9). The ISQ value was the highest in the mandibular premolar site (81.5+/-2.4) followed by the mandibular molar site (80.0+/-5.7), maxillary anterior site (77.4+/-4.1), mandibular anterior site (76.4+/-11.9), maxillary premolar site (74.2+/-14.3) and maxillary molar site (73.7+/-7.4). The mean HU and ISQ value were similar in females and males. (HU: P=0.331, ISQ: P=0.595) No significant difference was also found in the age group respectively. However, the correlation coefficients between the variables showed a closed correlation between the HU and ISQ value. CONCLUSION: These results showed close correlation between the bone density (HU) and primary stability value (ISQ) at the time of implant installation (Correlation coefficients=0.497, P<0.01). These results strengthen the hypothesis that it might be possible to predict and quantify the initial implant stability and bone density from a presurgical CT diagnosis. These results strengthen the hypothesis that it might be possible to predict and quantify the initial implant stability and bone density from a presurgical CT diagnosis.

Comparion of stability in titanium implants with different surface topographies in dogs

STATEMENT OF PROBLEM: A few of studies which compared and continuously measured the stability of various surface treated implants in the same individual had been performed. PURPOSE: We aim to find the clinical significance of surface treatments by observing the differences in the stabilization stages of implant stability. MATERIAL AND METHODS: Eight different surface topographies of dental implants were especially designed for the present study. Machined surface implants were used as a control group. 4 nano-treated surface implants (20 nm TiO2 coating surface, heat-treated 80 nm TiO2 coating surface, CaP coating surface, heat treated CaP coating surface) and 3 micro-treated surface implants [resorbable blast media (RBM) surface, sandblast and acid-etched (SAE) surface, anodized RBM surface] were used as experiment groups. All 24 implants were placed in 3 adult dogs. Periotest(R) & ISQ values measured for 8 weeks and all animals were sacrificed at 8 weeks after surgery. Then the histological analyses were done. RESULTS: In PTV, all implants were stabilized except 1 failed implants. In ISQ values, The lowest stability was observed at different times for each individual. The ISQ values were showed increased tendency after 5 weeks in every groups. After 4 to 5 weeks, the values were stabilized. There was no statistical correlation between the ISQ values and PTV. In the histological findings, the bone formation was observed to be adequate in general and no differences among the 8 surface treated implants. CONCLUSIONS: In this study, the difference in the stability of the implants was determined not by the differences in the surface treatment but by the individual specificity.

Influence of implant diameter and length changes on initial stability / 대한치과보철학회지

STATEMENT OF PROBLEM: Adequate bone quality and quantity were important to achieve initial stability and to prevent early failures. However there were few published data available regarding the actual effect of dimensional change in implant geometry on initial stability. PURPOSE: The purpose of the current study was to investigate the influence of diameter and length changes on initial stability of implants. MATERIAL AND METHODS: Four types of dummy bone (D1, D2, D3 and D4) consisted of cortical and cancellous layers with different thickness were simulated. Implants which had similar surface area to each other (3.5 x 13.0-mm, 4.0 x 11.5-mm, 4.5 x 10.0-mm, 5.0 x 8.5-mm) were inserted in dummy bones. Implant stability as a function of peak insertion torque and resonance frequency values were recorded for each implant. RESULTS: 1. Bone quality was a major influential factor to achieve initial stability (P .05), however insertion torques were increased with wider and shorter implants (P < .05). 3. In D4 dummy bone, implant stability quotient values and insertion torques were decreased with wider and shorter implants (P <. 05). CONCLUSION: From a point of view of initial stability, it is suggested that use of wide and short implant may be helpful in avoiding bone augmentation procedures in area of adequate bone quality.

Influence of implant fixture design on implant primary stability / 대한치과보철학회지

STATEMENT OF PROBLEM: Current tendencies of the implant macrodesign are tapered shapes for improved primary stability, but there are lack of studies regarding the relationship between the implant macrodesign and primary stability. PURPOSE: The purpose is to investigate the effect of implant macrodesign on the implant primary stability by way of resonance frequency analysis in the bovine rib bones with different kinds of quality. MATERIAL AND METHOD: Fifty implants of 6 different kinds from two Korean implant systems were used for the test. Bovine rib bones were cut into one hundred pieces with the length of 5 cm. Among them forty pieces of rib bones with similar qualities were again selected. For the experimental group 1, the thickness of cortical part was measured and 20 pieces of rib bones with the mean thickness of 1.0mm were selected for implant placement. For the experimental group 2, the cortical parts of the remaining 20 pieces of rib bones were totally removed and then implants were placed on the pure cancellous bone according to the surgical manual. After placement of all implants, the implant stability quotient(ISQ) was measured by three times, and its statistical analysis was done. RESULTS: There are statistically significant differences in ISQ values among 4 different kinds of Avana system implants in the experimental group 2. For the experimental group 1, Avana system implants showed significantly different ISQ values, but when differences in the thickness of cortical parts were statistically considered, did not show any significant differences in ISQ values. Among Oneplant system implants, there are no significant differences in ISQ values for the experimental group 2 as well as for the experimental group 1. CONCLUSION: Within the limits of this study, bone quality and implant design have some influences on the primary stability of implants. Especially in the bone of poor quality, tapered shape of implants are more favorable for the primary stability of implants.

The effect of different surface treatment on the osseointegration and stability of implants / 대한치과보철학회지

PURPOSE: This experiment examined the effect of different surface treatment on the osseointegration and stability of implants. MATERIAL AND METHODS: In this study, 40 each of machined, SLA and RBM implants, which are the most commonly used implants, were implanted into the tibia of 20 normal rabbits using OsseoCareTM. The rabbits were sacrificed after 1 week, 4 weeks, 8 weeks and 12 weeks for implant stability analysis, removal torque analysis, histologic and histomorphometric analysis. RESULT: ISQ showed significant difference between Machined and RBM at first week and at 4 weeks. There was significant difference between Machined and both SLA and RBM(p<0.05) but after 8 weeks there were no significant difference between each group. In the removal torque, RBM showd significantly higher values than SLA and Machined surface at 1st week. At 4th and 12th week, there was significant difference between Machined and SLA, RBM(p<0.05). In the bone to implant contact variable, there was no significant difference between each surface treatment method. In the Machined surface group, there was no significant difference between each time interval, but in SLA group, there were significant differences between the 1st week and 12th week. and in RBM group, there were significant differences between the 1st week and 8th, 12th week and between 4th and 12th week(p<0.05). The bone area showed significantly higher values in SLA and RBM compared to Machined surface 1st and 8th week and significantly higher values in SLA than Machined surface at the 4th week(p<0.05). CONCLUSION: The roughened surface of implants showed positive effect in the early stages of implantation and assisted in bone formation. After the bone formation stage, there was no statistical difference between Machined and roughened surface groups. In dental implantation, where initial stability is critical to the success of implants, the use of roughened surface implants should assist in reducing the healing period after implantation.

Application of resonance frequency analysis in measuring the stability of implants / 国际生物医学工程杂志

Resonance frequency analysis(RFA) has been successfully applied to measure the stability of implants, and proved to an objective method. Domestic and international scholars in the field of organ implantation have paid great attention on RFA in recent years. The present paper systematically introduces principles and applications of RFA in buccal medicine. The advantages and insufficiencies of RFA are discussed too.

A study on the correlation between implant stability values and initial insertion torque / 대한치과보철학회지

Statement of problem. Osseointegration is important mechanism of dental implant but it is not easy to evaluate. Indirect measurement is non-invasive and clinically applicable but they need more study about correlation between indirect values and degree of osseointegration. Purpose. The aims of this study were to evaluate the coefficient of correlation between indirect measurement and direct measurement under different healing time, and assessment of effect of initial insertion torque to the implant stability. Material and Methods. 20 rabbits received 3 implants on each side of tibia. Three kinds of implants (machined surface implant, Sandblasted with Large grit and Acid etched implant, Resorbable Blast Media treated implant) were used. During the surgery implant insertion torque were measured with OsseocareTM. After the 1, 4, 8, 12 weeks of healing time, animals were sacrificed and stability values (Implant Stability Quotient with OsstellTM, removal torque with torque gauge) were measured. Results. The Bone quality of rabbit tibia was classified into 2 groups according to the insertion torque. Resonance frequency analysis (ISQ) and removal torque showed positive correlation until 4th week (r=0.555, p=0.040). After 8th week (r=-0.011, p=0.970) the correlation became weak and it turned negative at 12th week (r=-0.074, p=0.801). Insertion torque and ISQ showed changing correlation upon the healing time (1st week: r=0.301, p=0.033, 4th week: r=-0.429, p=0.018, 8th week: r=0.032, p=0.865, 12th week: r=-0.398, p=0.029). Insertion torque and removal torque has positive correlation but it was not statistically significant (1st week: r=0.410, p=0.129, 4th week: r=-0.156, p=0.578, 8th week: r=0.236, p=0.398, 12th week: r=-0.260, p=0.350). Conclusion. In this study, bone quality may affect the degree of osseointegration positively during healing time and correlation between ISQ and degree of osseointegration can be different according to the healing time and bone quality.

The stability of osseointegrated implants and the relative factors / 实用口腔医学杂志

0.05). Conclude:The bone type may affect the stability of ITI osseointegrated implants.