Bone density and implant stability with advanced platelet-rich fibrin in immediately loaded- implant assisted mandibular overdentures / Densidade óssea e estabilidade dos implantes com fibrina rica em plaquetas avançada em overdentures mandibulares com carga imediata

ABSTRACT Objective: The aim of this study is to determine the effect of Advanced Platelet-Rich Fibrin on bone density and implant stability in immediately loaded- implant-assisted mandibular overdentures (Split-mouth study). Material and Methods: Ten completely edentulous patients received two implants in the mandibular canine region and locator attachments were used to retain immediately loaded- implant mandibular overdentures. Each patient served in two Groups, one Group for each side. One side of the mandible received an implant with topical application of Advanced Platelet-Rich Fibrin in the implant osteotomy site (Group I) and the other site received an implant without application of Advanced platelet-rich fibrin (Group II). Each patient was examined clinically for implant stability using Osstell Mentor device and radiographically by ultra-low dose CT scan to measure bone density around the implant at baseline, three, six months, and one year. Results: There were no statistically significant differences (P>.05) in bone density and implant stability among the studied Groups during one year follow-up period. Conclusion : Advanced Platelet-Rich Fibrin has no effect on bone density and implant stability in immediately loaded implant-assisted mandibular overdenture.(AU)

RESUMO Objetivo: O objetivo deste estudo é determinar o efeito da Fibrina Rica em Plaquetas Avançada na densidade óssea e estabilidade dos implantes em Overdentures mandibulares com carga imediata (estudo de boca dividida). Material e Métodos: Dez pacientes edêntulos foram submetidos à instalação de dois implantes mandibulares na região dos caninos e pilares locator foram utilizados como sistema de retenção para as overdentures mandibulares com carga imediata. Cada paciente participou nos dois grupos, sendo um grupo para cada lado. Um lado da mandíbula recebeu implante com aplicação tópica de Fibrina Rica em Plaquetas Avançada no local do sítio cirúrgico do implante (Grupo I) e o outro local recebeu implante sem aplicação de Fibrina Rica em Plaquetas Avançada (Grupo II). Cada paciente foi examinado clinicamente quanto à estabilidade do implante usando o dispositivo Osstell Mentor e radiograficamente por tomografia computadorizada de ultrabaixa dose para medir a densidade óssea ao redor do implante no início do estudo, três, seis meses e um ano. Resultados: Não houve diferenças estatisticamente significativas (P>0,05) na densidade óssea e na estabilidade do implante entre os grupos estudados durante o período de acompanhamento de um ano. Conclusão: A Fibrina Rica em Plaquetas Avançada não tem efeito na densidade óssea e na estabilidade de implantes em Overdentures mandibulares com carga imediata (AU)

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.

Estabilidad primaria en implantes inmediatos versus implantes colocados en hueso maduro: un estudio clínico retrospectivo / Primary stability in immediate implants versus implants placed in mature bone: a retrospective clinical study

La estabilidad primaria es un requisito importante para la supervivencia y éxito de los implantes durante la osteointegración. En los últimos años, los implantes inmediatos postextracción han demostrado ser una opción de tratamiento exitosa y predecible para la reposición de dientes con mal pronóstico, pero surge la duda de si dichos implantes alcanzan valores de estabilidad primaria comparables a aquellos colocados en hueso maduro. Comparar la estabilidad primaria de implantes inmediatos colocados en alveolos postextracción con la de implantes colocados en hueso maduro. Se llevó a cabo un estudio clínico retrospectivo, con los datos recogidos sobre 175 implantes, colocados en 175 pacientes. Todos los implantes colocados pertenecían al modelo Essential Cone (Klockner Implant System) y se dividieron en dos grupos: implantes inmediatos (Grupo A, n=31) e implantes colocados en hueso maduro (Grupo B, n=144). La estabilidad primaria de todos los implantes se midió mediante torque de inserción y análisis de frecuencia de resonancia con Osstell ISQ. No se encontraron diferencias estadísticamente significativas respecto a la estabilidad medida a través del torque de inserción (26,29+10,07 Vs 25,76+9,72 N/cm) pero sí que se encontraron diferencias significativas en la medida de la estabilidad primaria mediante AFR, siendo inferiores los valores correspondientes a los implantes colocados en los alveolos post exodoncia (60,74 ± 6,17 en sentido VL y 62,19 ± 7.64 en sentido MD frente a 68,34 ± 6.26 en sentido VL y 69,29 ± 7.98 en sentido MD obtenidos en los implantes colocados en hueso maduro). El torque de inserción de los implantes inmediatos es similar al de los implantes colocados en hueso maduro, pero sus valores ISQ son significativamente inferiores, lo que demuestra un mayor grado de micromovimiento, y por consiguiente, un mayor riesgo de fracaso durante el período de osteointegración.

Primary stability is an important requirement for the survival and success of implants during osseointegration. In recent years, immediate post-extraction implants have proven to be a successful and predictable treatment option for the replacement of teeth with a poor prognosis, but the question arises as to whether these implants reach primary stability values comparable to those placed in mature bone. The objective of the study was to compare the primary stability of immediate implants placed in post-extraction alveoli with that of implants placed in mature bone. A retrospective clinical study was carried out, with data collected on 175 implants, placed in 175 patients. All implants placed belonged to the Essential Cone model (Klockner Implant System) and were divided into two groups: immediate implants (Group A, n = 31) and implants placed in mature bone (Group B, n = 144). The primary stability of all implants was measured by insertion torque and resonance frequency analysis with Osstell ISQ. No statistically significant differences were found regarding the stability measured through the insertion torque (26.29 + 10.07 Vs 25.76 + 9.72 N / cm) but significant differences were found in the measurement of primary stability by means of AFR, the values corresponding to implants placed in the post-exodontic alveoli being lower (60.74 ± 6.17 in the VL direction and 62.19 ± 7.64 in the MD direction versus 68.34 ± 6.26 in the VL direction and 69.29 ± 7.98 in the MD direction obtained in implants placed in mature bone). The insertion torque of immediate implants is similar to that of implants placed in mature bone, but their ISQ values are significantly lower, which demonstrates a higher degree of micromotion, and therefore, a greater risk of failure during the period of osseointegration.

Innovative method “DV-PIMS” technique and dental implant design for grafting injectable platelet-rich fibrin around the dental implant – Goat jaw cadaver study

Aims: Dental implants have revolutionized the treatment modality for replacing missing teeth. The ability of implants to osseointegrate with the bone leads to its success. The problem is sometimes there is inadequate bone available for implant. If hygiene is not maintained, biofilms of bacteria can be formed around the dental implant. One approach to this problem has been development of bioactive surgical additives. Platelet-rich fibrin (PRF) appears as an alternative. There are various techniques of using PRF. These techniques need skill and practice to use PRF. Objective: To evaluate implant stability and flow of injectable PRF (i-PRF) of regular implant and modified innovative design implant. Materials and Methods: Thirty goat jaw bones were selected. Implants were placed in mandibular posterior region. Fifteen implants were placed using regular dental implant system (Group A) on the left side of jaw bone. The other 15 implants were placed using modified dental implant (Group B) on the right side of jaw bone. The body of these implants at middle has drainage vents to drain/flow the i-PRF-like dye. The dye was injected through regular and modified implants (DV-PIMS technique). Then the stability was checked with the help of Periotest. Cross section was taken 3 cm away from dental implant at the angle of mandible, to check the flow of i-PRF/platelet-rich plasma (PRP)-like dye. Results: Periotest evaluation showed a mean of 2.3 for implant Group B and a mean of 1.5 for implant Group A. The flow of i-PRF-like dye was seen in Group B, and Group A does not show any flow. Conclusion: There are various techniques of using PRF. These techniques need skill and practice to use PRF. This (DV-PIMS) method aims to explain new implant design that disperses an i-PRF solution from inside out. The screw section of the new implant is made of a reservoir running vertically down inside. That reservoir is filled with (injectable) PRF, and then a cover screw is placed. The solution will begin to slowly diffuse out, through the vents in implant, keeping biofilms from forming or avoiding at the screw–bone interface and accelerate healing process.

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.

Influência do número de roscas e da densidade dos blocos de poliuretano na estabilidade primária de implantes do sistema intraoss / The influence of implant thread number and polyurethane block density on primary stability values of the Intraoss implant system

Objetivo: avaliar e comparar a estabilidade primária dos implantes cilíndricos de 3,75 mm x 11 mm Titaoss e Titaoss dupla rosca, do Sistema Intraoss, instalados em blocos de poliuretano com baixa densidade. Material e métodos: foram realizadas 32 cavidades em dois blocos de poliuretano, simulando as densidades de ossos tipo III e IV. As estabilidades dos implantes foram mensuradas por meio do torque de inserção e frequência de ressonância. Resultados: os implantes Titaoss instalados no osso tipo III apresentaram valores de torque de inserção de 43,1 ± 14,87 Ncm, enquanto os valores dos implantes Titaoss dupla rosca foram 46,9 ± 5,3 Ncm. No osso tipo IV, os implantes Titaoss apresentaram valores de 30 ± 0,0 Ncm e os dupla rosca de 29,4 ± 1,77 Ncm. Não houve diferença significante na estabilidade primária entre os grupos dos implantes (p > 0,05) instalados no mesmo tipo de osso. Os implantes Titaoss instalados no osso tipo III apresentaram valores de ISQ de 57,3 ± 4,69, ao passo que os valores para os implantes Titaoss dupla rosca foram 54,9 ± 3,98. No osso tipo IV, os implantes Titaoss apresentaram valores de 48,4 ± 4,07 ISQ e os dupla rosca de 50,8 ± 3,98 ISQ. As estabilidades primárias dos implantes foram maiores no osso tipo III quando comparado ao IV (p < 0,05). Conclusão: os dois desenhos de implantes permitem a obtenção da estabilidade primária para a técnica da carga mediata. No entanto, para submeter esses tipos de implante à carga imediata, indica-se a técnica da subfresagem.

Objectives: this in vitro study aimed to evaluate and compare the primary stability of the cylindrical implants (3.75 mm x 11 mm) Titaoss and Titaoss double thread from Titaoss System placed in cavities made of low-density polyurethane blocks. Material and methods: 32 cavities were made in two types of polyurethane blocks simulating the type III and IV bone densities. The implant stability values were measured using the final insertion torque and resonance frequency analysis. Results: the Titaoss implants placed in type III bone achieved 43.1 ± 14.87 Ncm, while the double-thread values were 46.9 ± 5.3 Ncm. For bone type IV, the Titaoss implants reached 30Ncm and the double thread 29.4± 1.77 Ncm. No statistically significant differences on implant stability were seen for both groups (p > 0.05) for the same bone type. the Titaoss implants in bone type III had 57.3 ± 4.69 and the double thread 54.9 ± 3.98 ISQ values. In type IV bone, Titaoss reached 48.4 ± 4.07 and the double thread 50.8 ± 3.98 ISQ units. The primary stability values were greater at type III than type IV bone (p < 0.05). Conclusion: both implant designs allow for primary stability. However, the use of an underpreparation technique is recommended in cases of immediate loading protocols.

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.

Differences in percussion-type measurements of implant stability according to height of healing abutments and measurement angle / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the effect of healing abutment height and measurement angle on implant stability when using Periotest and AnyCheck. MATERIALS AND METHODS: 60 implants were placed into artificial bone blocks. After implant insertion, 2, 3, 4 and 5 mm healing abutments were installed on 15 specimens, respectively. Insertion torque value, implant stability test, Periotest value were measured. Insertion torque value was controlled between 45 – 55 Ncm. AnyCheck was used for measuring implant stability test and Periotest M was used for measuring Periotest value. Implant stability test and Periotest value were measured at the angles of 0 and 30 degrees to the horizontal plane. Measured values were analyzed statistically. RESULTS: Insertion torque value had no significant difference among groups. When healing abutment height was higher, implant stability test and Periotest value showed lower stability. Also when measurement angle was decreased, implant stability test and Periotest value showed lower stability. CONCLUSION: When measuring stability of implants with percussion type devices, measured values should be evaluated considering height of healing abutments and measurement angle.

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

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

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>

The rate and stability of mandibular block bone graft in recent 5 years / 대한악안면성형재건외과학회지

BACKGROUND: The purposes of the present study were to compare implant stabilities of mandibular block bone graft and bovine bone graft and to evaluate influencing factors for implant stability in mandibular block bone (MBB) graft. METHODS: This retrospective study investigated 1224 cases and 389 patients treated by one surgeon in the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital (Yangsan, Korea) between January 2010 and December 2014. Proportions that MBB graft cases constitute in all implant restoration cases and in all bone graft cases were measured. Implant stability quotient (ISQ) values were achieved by the same surgeon before loading. The average ISQ values of the experimental groups were compared. In addition, ISQ values of influencing factors, such as age, sex, implant size, and implant placement site, were compared within the MBB group using OsstellTM Mentor (Osstell®, Göteborg, Sweden). Paired t test and ANOVA were conducted for statistical analysis with a significance level of 0.05. RESULTS: Fifty-five percent of all implant restoration cases performed bone graft while MBB cases constituted 34% of all implant restoration cases and 61% of all bone graft cases. Comparing ISQ values according to bone graft materials, the MBB group manifested sufficient implant stability by presenting comparable ISQ value to that of the experimental group without bone graft. Among the reviewed factors, females, mandibular molar regions, and implants in larger diameter displayed greater implant stabilities. CONCLUSIONS: Satisfactory implant stability was accomplished upon administration of MBB graft. Within the limitation of this study, gender, implant site, and implant diameter were speculated to influence on implant stability in MBB graft.

Assessment of Implant Stability: Methods and Recent Advances.

Achieving primary stability is of greatest importance, at the time of implant placement. A rigid fixation of implant within the host bone, in absence of micromotion is the most critical factor for successful osseointegration. Over the years, several authors have reported various methods in literature to monitor implant stability, which include, tapping the abutment with a metallic instrument, histomorphometry test, removal torque test, cutting torque test, radiography, periotest, and resonance frequency analysis. Resonance frequency analysis (RFA) offers a clinical, objective way to measure stability and presumed osseointegration of implants. The review focuses on different methods used to assess implant stability and recent advances in this field.

Accuracy of resonance frequency analysis by third generation Osstell® / Precisión del análisis de frecuencia de resonancia mediante Osstell® de tercera generación

The Resonance Frequency Analysis by Osstell® is used in the assessment of primary and secondary implant stability. The aim of this study was to determine its accuracy as a method of testing, checking its repeatability and reproducibility. A pilot study was performed whereby implants were placed in a cow rib to compare several ISQ measurements with the same SmartPeg transducer (repeatability), or with different SmartPegs (reproducibility). Statistical analysis of the data showed a high correlation of the ISQ values obtained in both assays, which suggests that Osstell®analysis can provide high repeatability and reproducibility.

El análisis de frecuencia de resonancia (AFR) por Osstell® se utiliza en la evaluación de la estabilidad primaria y secundaria del implante. El objetivo del presente estudio fue establecer la precisión del AFR mediante Osstell©, como método de prueba empleado en la determinación de la estabilidad implantaria. Se realizó un estudio experimental in vitro, en el que se colocaron implantes en una costilla de vaca y compararon diferentes mediciones del coeficiente de estabilidad del implante (ISQ) obtenidas sobre estos implantes con un mismo transductor SmartPeg (repetibilidad) o con diferentes SmartPegs (reproductibilidad). El análisis estadístico de los datos mostró una elevada correlación de los ISQ obtenidos en ambos ensayos, lo cual sugiere una reproductibilidad y repetibilidad elevada del análisis mediante Osstell.

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.

Influence of insertion torque on primary stability of dental implants in beagle / 实用医学杂志

Objective To investigate the correlation between the insertion torque values and primary stability of dental implants using different insertion torque values ,and search for the best insertion torque values that can acquire good primary stability. Methods Six male pure beagles were selected, and the first molars and four premolars of bilateral mandibulars were extracted. Three months later, a total of 48 XIVE dental implants were inserted. All implants were divided into group A, group B, group C, and group D based on the insertion torque value (ITV): group A, 0 0.05). Conclusion With the limitations of the study, it was concluded the primary stability does not simply depend on the insertion torque;When the insertion torque value was no less than 20Ncm, the dental implant can acquire good primary stability.

Geometrical design characteristics of orthodontic mini-implants predicting maximum insertion torque / 대한치과교정학회지

OBJECTIVE: To determine the unique contribution of geometrical design characteristics of orthodontic mini-implants on maximum insertion torque while controlling for the influence of cortical bone thickness. METHODS: Total number of 100 cylindrical orthodontic mini-implants was used. Geometrical design characteristics of ten specimens of ten types of cylindrical self-drilling orthodontic mini-implants (Ortho Easy(R), Aarhus, and Dual Top(TM)) with diameters ranging from 1.4 to 2.0 mm and lengths of 6 and 8 mm were measured. Maximum insertion torque was recorded during manual insertion of mini-implants into bone samples. Cortical bone thickness was measured. Retrieved data were analyzed in a multiple regression model. RESULTS: Significant predictors for higher maximum insertion torque included larger outer diameter of implant, higher lead angle of thread, and thicker cortical bone, and their unique contribution to maximum insertion torque was 12.3%, 10.7%, and 24.7%, respectively. CONCLUSIONS: The maximum insertion torque values are best controlled by choosing an implant diameter and lead angle according to the assessed thickness of cortical bone.

Avaliação da estabilidade do implante pela análise da frequência de ressonância: estudo in vivo com carregamento imediato e precoce em um modelo em cães / Evaluation of implant stability by means of resonance frequency analysis: an in vivo study with immediate and early loading in the dog model

Este estudo teve por objetivo avaliar a estabilidade de implantes de carga imediata ou precoce, em diferentes intervalos de tempo. Material e Métodos: foram extraídos os pré-molares mandibulares, bilateralmente, de oito cães e, após 12 semanas, cada cão recebeu seis implantes (três em cada lado da mandíbula). A carga foi aplicada em pares, em um implante de cada lado, sendo que o primeiro par recebeu carga imediata, o segundo par após sete dias, e o terceiro par após 14 dias. Em cada período, as medidas de estabilidade dos implantes foram realizadas por frequência de ressonância (ISQ). Após 12 semanas, uma nova leitura da estabilidade dos implantes foi realizada. A análise estatística foi feita usando modelo linear de efeitos mistos, que é uma generalização do modelo linear padrão (Anova). Diferenças foram consideradas significantes quando p < 0,05. Resultados: a estabilidade do implante mudou no decorrer do tempo para todos os protocolos de carga, apresentando aumento significativo na estabilidade final, mas as variações foram semelhantes para os três grupos estudados. Nos períodos de sete dias e 14 semanas, o protocolo de carga imediata apresentou menor estabilidade de implante do que os protocolos de sete e 14 dias. Conclusão: a estabilidade do implante diminui nos períodos iniciais após a cirurgia e aumenta no período de 14 semanas. A estabilidade dos implantes do protocolo de carga imediata é menor do que a dos protocolos de sete e 14 dias, sugerindo cautela para seu uso...

This study aimed to evaluate implant stability in function with immediate or early loading protocols at different time intervals. Material and Methods: The mandibular premolars of eight dogs were pulled bilaterally. After 12 weeks, each dog received 6 implants (3 at each mandibular side). Implant loading was performed for each implant pair according to the following periods: immediate (fi rst pair), 7 days later (second pair), 14 days later (third pair). Implant stability measurements were performed by means of resonance frequency for each period. After 12 weeks, new readings of implant stability were obtained. The statistical analysis was performed using a mixed linear model, which is a generalization of the standard linear model (Anova), with differences considered signifi cant at p<0.05. Results: Implant stability changed throughout time for all loading protocols, presenting a significant increase in fi nal stability values, but variations were similar for the three studied groups. At 7- and 14-week periods, immediate loading protocol presented lower implant stability than 7-day or 14-day protocols. Conclusions: Implant stability diminishes in the initial periods after surgery, and increases in a 14-week period. In the middle-term, there were no statistically significant differences in the stability of immediately-loaded implants, one or two weeks after implant placement...

Retrospective study of implant stability according to the implant length, diameter and position / 대한치과보철학회지

PURPOSE: The aim of this retrospective study was to evaluate the influence of implant diameter, length and placement to implant stability. MATERIALS AND METHODS: Total 90 implants (US II plus(TM), Osstem co, Busan, Korea) of 72 patients were determined as experimental samples. The factors of diameters(o 4 mm, o 5 mm), lengths (10 mm, 11.5 mm, 13 mm), and implant placement (maxilla, mandible) were analyzed. The stability of the implants was measured by resonance frequency analysis (RFA) at the time of implant placement and impression taking. The difference of ISQ values according to patient's gender was evaluated by Independent t-test. ISQ values were compared between implant diameter, length and placement using one-way ANOVA and Tukey HSD test (alpha=.05). To compare ISQ values between at the time of surgery and impression taking, paired t-tests were used (alpha=.05). RESULTS: The change of implant length did not show significant different on the ISQ value (P>.05). However, 5 mm diameter implants had higher ISQ values than 4 mm diameter implants (P<.05). Implants placed on the mandible showed significantly higher ISQ values than on the maxilla (P<.05). CONCLUSION: In order to increase implant stability, it is better to select the wider implant, and implants placed on mandible are possible to get higher stability than maxilla. ISQ values at impression taking showed higher implant stability than ISQ values at implant placement, it means that RFA is clinically effective method to evaluate the change of implant stability through the osseointegration. The consideration of the factors which may affect to the implant stability will help to determine the time of load applying and increase the implant success rate.

Evaluation on the efficacy and safety of calcium metaphosphate coated fixture

PURPOSE: The purpose of this study was to assess the difference in efficacy between calcium metaphosphate (CMP)-coated implant fixtures and conventional resorbable blasted media (RBM) processed implant fixtures. MATERIALS AND METHODS: This study targeted 50 implants from 44 patients who visited Dankook University Dental Hospital. Implantations were done separately for RBM treated and CMP-coated implants, although their design was the same. Calcium metaphosphate has a quicker biodegradation process through hydrolysis compared to other phosphate calcium groups. For the first year of the implantation, the resorption volume of marginal bone analyzed via radiography and perio-test value were measured, under the check plan. Their analyses were composed of a non-inferiority trials test. A 95% level of reliability was used. RESULTS: In the comparative analysis of the resorption volume of marginal bone and the perio-test value, no statistically significant difference was found between the CMP-coated implants and RBM implants. CONCLUSION: One year after the implant placement, CMP-coated implants were found not to be inferior to the conventional RBM implants.

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.