scholarly journals Preoperative Computed Tomography-Derived Bone Densities in Hounsfield Units at Implant Sites Acquired Primary Stability

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Kyou Hiasa ◽  
Yasuhiko Abe ◽  
Yohei Okazaki ◽  
Keisuke Nogami ◽  
Wataru Mizumachi ◽  
...  
Keyword(s):  
Primary Stability ◽  
Multiple Comparisons ◽  
Implant Stability ◽  
Hounsfield Units ◽  
Anterior Maxilla ◽  
Posterior Maxilla ◽  
Preoperative Ct ◽  
The Mean ◽  
Ct Data ◽  
Anterior Mandible

The purpose of this study was to evaluate preoperative CT-derived bone densities in Hounsfield units (HU) at implant sites that acquired primary stability, and to compare these values to the optimal bone densities proposed in the literature. Fifty-one patients, 18 males (37 implant sites) and 33 females (67 implant sites) between 2003 and 2010 were assessed. CT data for different jaw sections, regions, and operating procedures were compared using the Kruskal-Wallis test and Scheffe's test for multiple comparisons (P<0.05). The mean bone density in the maxilla was significantly lower than that in the mandible (P<0.05); the mean bone densities in the 4 jaw regions decreased in the following order: anterior mandible > anterior maxilla > posterior mandible > posterior maxilla. The bone densities assessed by HU fell into the range of optimal bone densities associated with acquired primary implant stability proposed in the literature.

Resonance Frequency Analysis of 208 Straumann Dental Implants During the Healing Period

2013 ◽  
Vol 39 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Ahmet Umut Guler ◽  
Mahmut Sumer ◽  
Ibrahim Duran ◽  
Elif Ozen Sandikci ◽  
Nazife Tuba Telcioglu
Keyword(s):  
Dental Implant ◽  
Implant Stability ◽  
Anterior Maxilla ◽  
Implant Placement ◽  
Healing Period ◽  
Posterior Maxilla ◽  
Significant Difference ◽  
Final Measurement ◽  
Diagnostic Benefit ◽  
Anterior Mandible

The most important prerequisite for the success of an osseointegrated dental implant is achievement and maintenance of implant stability. The aim of the study was to measure the 208 Straumann dental implant stability quotient (ISQ) values during the osseointegration period and determine the factors that affect implant stability. A total of 164 of the implants inserted were standard surface, and 44 of them were SLActive surface. To determine implant stability as ISQ values, measurements were performed at the stage of implant placement and healing periods by the Osstell mentor. The ISQ value ranges showed a significant increase during the healing period. Except for the initial measurement, the posterior maxilla had the lowest ISQ values, and there was no significant difference among anterior mandible, posterior mandible, and anterior maxilla (P &lt; .05). Implant length did not have a significant influence on ISQ value (P &gt; .05). The second measurement was significantly higher in men compared with women (P &lt; .05). The second measurement was significantly higher than the others at 4.8 mm, and for the final measurement, there were no significant differences between 4.8 and 4.1 mm, which were higher than 3.3 mm (P &lt; .05). When comparing sandblasted, large-grit, acid-etched (SLA) and SLActive surface implants, there were no significant differences for insertion measurements, but for second measurements, SLActive was significantly higher (P = 0), and for the final measurement, there was no significant difference. It appears that repeated ISQ measurements of a specific implant have some diagnostic benefit, and the factors that affect implant stability during the healing period are presented.

Influence of implant design, length, diameter, and anatomic region on implant stability: a randomized clinical trial

2021 ◽  
Vol 61 (1) ◽  
Author(s):  
André Moreira ◽  
◽  
José Rosa ◽  
Filipe Freitas ◽  
Helena Francisco ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Primary Stability ◽  
Implant Design ◽  
Implant Stability ◽  
Anterior Maxilla ◽  
Implant Stability Quotient ◽  
Relevant Effect ◽  
Posterior Maxilla ◽  
Significant Difference ◽  
Secondary Stability

Objectives: To evaluate the influence of implant geometry and anatomical region on implant stability. Methods: A randomized controlled clinical trial was conducted on 45 patients, in whom a total of 79 implants were placed: 40 MIS C1 Implants and 39 MIS Seven Implants. The implant stability quotient was measured using resonance frequency analysis immediately after implant placement and 8 weeks later with an Osstell Mentor device. Results: 76 implants were analyzed. The implant stability quotient was statistically significantly higher for secondary stability than primary stability (68.7±8,6 vs. 65.2±10.3, respectively, p=0.023). Considering primary stability, no statistical differences were found between the implant lengths 8.0 mm, 10.0 mm, 11.0 mm, and 11.5 mm (67.9±7.6, 63.9±10, 57.2±11.1, and 66.4±11.3, respectively, p=0.312). The same was observed for secondary stability (68.4±9.4, 67.9±9.3, 74.7±1.5, and 69.2±7.9, respectively, p=0.504). Also, there were no statistically significant differences between the implant diameters 3.75 mm and 4.20 mm concerning primary stability (64.3±8.7 and 66.1±11.7 respectively, p=0.445) or secondary stability (68.8±8.2 and 68.7±9.1 respectively, p=0.930). Regarding implant design, a statistically significant difference was found only for secondary stability, favoring MIS Seven implants (p=0.048). The intraoral location was statistically significant for both primary and secondary stability, as these were higher on the anterior maxilla than the posterior maxilla and mandible (p<0.05). Conclusions: The diameter and length of the implants studied did not influence their stability. Implant design may influence secondary stability, whereas intraoral location has a relevant effect on primary and secondary stability.

scholarly journals Influence of implant design, length, diameter, and anatomic region on implant stability: a randomized clinical trial

2021 ◽  
Vol 62 (1) ◽  
Author(s):  
André Moreira ◽  
◽  
José Rosa ◽  
Filipe Freitas ◽  
Helena Francisco ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Primary Stability ◽  
Implant Design ◽  
Implant Stability ◽  
Anterior Maxilla ◽  
Implant Stability Quotient ◽  
Relevant Effect ◽  
Posterior Maxilla ◽  
Significant Difference ◽  
Secondary Stability

Objectives: To evaluate the influence of implant geometry and anatomical region on implant stability. Methods: A randomized controlled clinical trial was conducted on 45 patients, in whom a total of 79 implants were placed: 40 MIS C1 Implants and 39 MIS Seven Implants. The implant stability quotient was measured using resonance frequency analysis immediately after implant placement and 8 weeks later with an Osstell Mentor device. Results: 76 implants were analyzed. The implant stability quotient was statistically significantly higher for secondary stability than primary stability (68.7±8,6 vs. 65.2±10.3, respectively, p=0.023). Considering primary stability, no statistical differences were found between the implant lengths 8.0 mm, 10.0 mm, 11.0 mm, and 11.5 mm (67.9±7.6, 63.9±10, 57.2±11.1, and 66.4±11.3, respectively, p=0.312). The same was observed for secondary stability (68.4±9.4, 67.9±9.3, 74.7±1.5, and 69.2±7.9, respectively, p=0.504). Also, there were no statistically significant differences between the implant diameters 3.75 mm and 4.20 mm concerning primary stability (64.3±8.7 and 66.1±11.7 respectively, p=0.445) or secondary stability (68.8±8.2 and 68.7±9.1 respectively, p=0.930). Regarding implant design, a statistically significant difference was found only for secondary stability, favoring MIS Seven implants (p=0.048). The intraoral location was statistically significant for both primary and secondary stability, as these were higher on the anterior maxilla than the posterior maxilla and mandible (p<0.05). Conclusions: The diameter and length of the implants studied did not influence their stability. Implant design may influence secondary stability, whereas intraoral location has a relevant effect on primary and secondary stability.

scholarly journals How Do Parameters of Implant Primary Stability Correspond with CT-Evaluated Bone Quality in the Posterior Maxilla? A Correlation Analysis

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 270
Author(s):  
Ji-Hyun Kim ◽  
Young-Jun Lim ◽  
Bongju Kim ◽  
Jungwon Lee
Keyword(s):  
Bone Density ◽  
Bone Quality ◽  
Objective Assessment ◽  
Primary Stability ◽  
Insertion Torque ◽  
Hounsfield Units ◽  
Stability Parameters ◽  
Posterior Maxilla ◽  
Different Types ◽  
Edentulous Patients

The aim of the present study was to evaluate correlations between bone density and implant primary stability, considering various determinants such as age, gender, and geometry of implants (design, diameter). Bone density of edentulous posterior maxillae was assessed by computed tomography (CT)-derived Hounsfield units, and implant primary stability values were measured with insertion torque and resonance frequency analysis (RFA). A total of 60 implants in 30 partially edentulous patients were evaluated in the posterior maxilla with two different types of dental implants. The bone density evaluated by CT-derived Hounsfield units showed a significant correlation with primary stability parameters. The bone quality was more influenced by gender rather than age, and the type of implant was insignificant when determining primary stability. Such results imply that primary stability parameters can be used for objective assessment of bone quality, allowing surgical modifications especially in sites suspected of poor bone quality.

scholarly journals Analysis of correlation between hounsfield units of CBCT scans and implant primary stability in implant stability quotient (ISQ)

2018 ◽  
Vol 29 ◽  
pp. 297-297
Author(s):  
Alexandre Campos Montenegro ◽  
Mario Vieira Neto ◽  
Gonçalo Pimentel Neto ◽  
Silvana Pizzini Montenegro ◽  
Kamila Temponi ◽  
...  
Keyword(s):  
Primary Stability ◽  
Implant Stability ◽  
Hounsfield Units ◽  
Implant Stability Quotient

scholarly journals The association between lower Hounsfield units on computed tomography and cage subsidence after lateral lumbar interbody fusion

2020 ◽  
Vol 49 (2) ◽  
pp. E8
Author(s):  
Zhuo Xi ◽  
Praveen V. Mummaneni ◽  
Minghao Wang ◽  
Huibing Ruan ◽  
Shane Burch ◽  
...  
Keyword(s):  
Interbody Fusion ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Lumbar Interbody Fusion ◽  
Hounsfield Units ◽  
Cage Subsidence ◽  
Preoperative Ct ◽  
Grade Ii ◽  
The Mean ◽  
Grade Iii

OBJECTIVEOne vexing problem after lateral lumbar interbody fusion (LLIF) surgery is cage subsidence. Low bone mineral density (BMD) may contribute to subsidence, and BMD is correlated with Hounsfield units (HUs) on CT. The authors investigated if lower HU values correlated with subsidence after LLIF.METHODSA retrospective study of patients undergoing single-level LLIF with pedicle screw fixation for degenerative conditions at the University of California, San Francisco, by 6 spine surgeons was performed. Data on demographics, cage parameters, preoperative HUs on CT, and postoperative subsidence were collected. Thirty-six–inch standing radiographs were used to measure segmental lordosis, disc space height, and subsidence; data were collected immediately postoperatively and at 1 year. Subsidence was graded using a published grade of disc height loss: grade 0, 0%–24%; grade I, 25%–49%; grade II, 50%–74%; and grade III, 75%–100%. HU values were measured on preoperative CT from L1 to L5, and each lumbar vertebral body HU was measured 4 separate times.RESULTSAfter identifying 138 patients who underwent LLIF, 68 met the study inclusion criteria. All patients had single-level LLIF with pedicle screw fixation. The mean follow-up duration was 25.3 ± 10.4 months. There were 40 patients who had grade 0 subsidence, 15 grade I, 9 grade II, and 4 grade III. There were no significant differences in age, sex, BMI, or smoking. There were no significant differences in cage sizes, cage lordosis, and preoperative disc height. The mean segmental HU (the average HU value of the two vertebrae above and below the LLIF) was 169.5 ± 45 for grade 0, 130.3 ± 56.2 for grade I, 100.7 ± 30.2 for grade II, and 119.9 ± 52.9 for grade III (p < 0.001). After using a receiver operating characteristic curve to establish separation criteria between mild and severe subsidence, the most appropriate threshold of HU value was 135.02 between mild and severe subsidence (sensitivity 60%, specificity 92.3%). After univariate and multivariate analysis, preoperative segmental HU value was an independent risk factor for severe cage subsidence (p = 0.017, OR 15.694, 95% CI 1.621–151.961).CONCLUSIONSLower HU values on preoperative CT are associated with cage subsidence after LLIF. Measurement of preoperative HU values on CT may be useful when planning LLIF surgery.

scholarly journals Relationship between Cortical Bone Thickness and Cancellous Bone Density at Dental Implant Sites in the Jawbone

Diagnostics ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 710
Author(s):  
Shiuan-Hui Wang ◽  
Yen-Wen Shen ◽  
Lih-Jyh Fuh ◽  
Shin-Lei Peng ◽  
Ming-Tzu Tsai ◽  
...  
Keyword(s):  
Bone Density ◽  
Cortical Bone ◽  
Dental Implant ◽  
Cancellous Bone ◽  
Bone Thickness ◽  
Anterior Maxilla ◽  
Cortical Bone Thickness ◽  
Posterior Maxilla ◽  
Dental Implant Surgery ◽  
Anterior Mandible

Dental implant surgery is a common treatment for missing teeth. Its survival rate is considerably affected by host bone quality and quantity, which is often assessed prior to surgery through dental cone-beam computed tomography (CBCT). Dental CBCT was used in this study to evaluate dental implant sites for (1) differences in and (2) correlations between cancellous bone density and cortical bone thickness among four regions of the jawbone. In total, 315 dental implant sites (39 in the anterior mandible, 42 in the anterior maxilla, 107 in the posterior mandible, and 127 in the posterior maxilla) were identified in dental CBCT images from 128 patients. All CBCT images were loaded into Mimics 15.0 to measure cancellous bone density (unit: grayscale value (GV) and cortical bone thickness (unit: mm)). Differences among the four regions of the jawbone were evaluated using one-way analysis of variance and Scheffe’s posttest. Pearson coefficients for correlations between cancellous bone density and cortical bone thickness were also calculated for the four jawbone regions. The results revealed that the mean cancellous bone density was highest in the anterior mandible (722 ± 227 GV), followed by the anterior maxilla (542 ± 208 GV), posterior mandible (535 ± 206 GV), and posterior maxilla (388 ± 206 GV). Cortical bone thickness was highest in the posterior mandible (1.15 ± 0.42 mm), followed by the anterior mandible (1.01 ± 0.32 mm), anterior maxilla (0.89 ± 0.26 mm), and posterior maxilla (0.72 ± 0.19 mm). In the whole jawbone, a weak correlation (r = 0.133, p = 0.041) was detected between cancellous bone density and cortical bone thickness. Furthermore, except for the anterior maxilla (r = 0.306, p = 0.048), no correlation between the two bone parameters was observed (all p > 0.05). Cancellous bone density and cortical bone thickness varies by implant site in the four regions of the jawbone. The cortical and cancellous bone of a jawbone dental implant site should be evaluated individually before surgery.

Stability Development of Immediately Loaded Hybrid Self-Tapping Implants Inserted in the Posterior Maxilla: 1-Year Results of a Randomized Controlled Trial

2017 ◽  
Vol 43 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Vladimir S. Todorovic ◽  
Miroslav Vasovic ◽  
Mia-Michaela Beetge ◽  
Andre W. van Zyl ◽  
Vladimir Kokovic
Keyword(s):  
Controlled Trial ◽  
Primary Stability ◽  
Implant Stability ◽  
Chemically Modified ◽  
Implant Placement ◽  
Early Results ◽  
Posterior Maxilla ◽  
Initial Drop ◽  
Modified Surface ◽  
Type 3

The objective of the present study was to elucidate stability development of immediately loaded hybrid self-tapping implants inserted in the posterior maxilla. Forty-eight hybrid self-tapping implants with a chemically modified surface (∅︀4.1; length: 8 mm) were inserted bilaterally in the maxillary first and second premolar and first molar sites of 8 patients. In each patient, both sides of the maxilla were assigned randomly to either immediate (IL) or early (EL) loading group. Implant stability was evaluated by means of resonance frequency analysis immediately after implant placement and after 1, 2, 3, 4, 5, 6, 12, 26, and 52 weeks. High values of primary stability were found in both groups (71.91 ± 6.52 implant stability quotient [ISQ] in IL group; 73.87 ± 6.5 ISQ in EL group), with significant differences between the groups at the different time points. Initial decrease in stability was observed between the first and fifth weeks in the IL group and between the first and third weeks for the EL group. In the IL group 1 implant was removed after 3 weeks due to lack of stability. Early results of this study showed the ability of hybrid self-tapping dental implants with a chemically modified surface to achieve sufficient primary stability and to maintain high values of secondary implant stability in bone type 3 and 4, even when loaded immediately. Minimal alterations in stability were observed for both investigated groups, but the EL group showed faster recovery after an initial drop in stability.

scholarly journals Does Implant Design Affect Implant Primary Stability? A Resonance Frequency Analysis–Based Randomized Split-Mouth Clinical Trial

2015 ◽  
Vol 41 (6) ◽  
pp. e281-e286 ◽  
Author(s):  
Sergio Alexandre Gehrke ◽  
Ulisses Tavares da Silva ◽  
Massimo Del Fabbro
Keyword(s):  
Standard Deviation ◽  
Resonance Frequency ◽  
Frequency Analysis ◽  
Primary Stability ◽  
Implant Design ◽  
Resonance Frequency Analysis ◽  
Implant Stability ◽  
The Mean ◽  
Group 2 ◽  
Group 1

The purpose of this study was to assess implant stability in relation to implant design (conical vs. semiconical and wide-pitch vs narrow-pitch) using resonance frequency analysis. Twenty patients with bilateral edentulous maxillary premolar region were selected. In one hemiarch, conical implants with wide pitch (group 1) were installed; in the other hemiarch, semiconical implants with narrow pitch were installed (group 2). The implant allocation was randomized. The implant stability quotient (ISQ) was measured by resonance frequency analysis immediately following implant placement to assess primary stability (time 1) and at 90 days after placement (time 2). In group 1, the mean and standard deviation ISQ for time 1 was 65.8 ± 6.22 (95% confidence interval [CI], 55 to 80), and for time 2, it was 68.0 ± 5.52 (95% CI, 57 to 77). In group 2, the mean and standard deviation ISQ was 63.6 ± 5.95 (95% CI, 52 to 78) for time 1 and 67.0 ± 5.71 (95% CI, 58 to 78) for time 2. The statistical analysis demonstrated significant difference in the ISQ values between groups at time 1 (P = .007) and no statistical difference at time 2 (P = .54). The greater primary stability of conical implants with wide pitch compared with semiconical implants with narrow pitch might suggest a preference for the former in case of the adoption of immediate or early loading protocols.

scholarly journals Computed tomography is not necessary to assess rotation of the femoral component in navigation-assisted total knee replacement

2016 ◽  
Vol 44 (6) ◽  
pp. 1314-1322 ◽  
Author(s):  
Daniel Hernández-Vaquero ◽  
Alfonso Noriega-Fernandez ◽  
Ivan Perez-Coto ◽  
Manuel A. Sandoval García ◽  
Andres A. Sierra-Pereira ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Total Knee Replacement ◽  
Femoral Component ◽  
Knee Replacement ◽  
Transepicondylar Axis ◽  
Component Rotation ◽  
Preoperative Ct ◽  
Total Knee ◽  
The Mean ◽  
Ct Data

Objective To demonstrate that postoperative computed tomography (CT) is not needed if navigation is used to determine the rotational position of the femoral component during total knee replacement (TKR). Methods Preoperative CT, navigational, and postoperative CT data of 70 TKR procedures were analysed. The correlation between the rotational angulation of the femur measured by CT and that measured by perioperative navigation was examined. The correlation between the femoral component rotation determined by navigation and that determined by CT was also assessed. Results The mean femoral rotation determined by navigation was 2.64° ± 4.34°, while that shown by CT was 6.43° ± 1.65°. Postoperative rotation of the femoral component shown by CT was 3.09° ± 2.71°, which was closely correlated with the angle obtained through the intraoperative transepicondylar axis by navigation (Pearson’s R = 0.930). Conclusions Navigation can be used to collect the preoperative, intraoperative, and postoperative data and final position of the TKR. The rotation of the femoral component can be determined using navigation without the need for CT.

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