Implant Length Research Articles

Distortion of digital panoramic radiographs used for implant site assessment.

Aims:This study is conducted to determine the amount of distortion of digital panoramic radiographs.Materials and Methods:Panoramic radiographs of all patients who received dental implants in the years 2012 and 2013 were selected from the records at the faculty of dentistry, King Abdulaziz University. Radiographs were analyzed using the R4 Kodak Software for linear measurements of implants length and width. The measurements were compared to the actual size of the implant, and the amount of distortion was calculated.Results:A total of 169 implants were analyzed. Horizontally, there was a statistically significant increase of 0.4 mm in width in the radiographic measurement compared to the actual size in the incisor region. Vertically, the sample overall exhibited a decrease by 0.4 mm compared to the actual size. Incisors had the highest difference with a decrease of 1.7 mm in the radiographic measurements compared to actual size. The highest distortion was found in the incisor region for both diameter and length (1.1 and 0.86), respectively.Conclusion:Digital panoramic radiographs show minimal to no distortion. The highest distortion is found in the anterior area.

Dose Intraoperative Fluoroscopy Precisely Predict Catheter Tip Location via Superior Vena Cava Route?

Adequate catheter tip location is crucial for functional intravenous port and central venous catheter. Numerous complications were reported because of catheter migration that caused by inadequate tip location. Different guidelines recommend different ideal locations without consensus. Another debate is actual movement of intravascular portion of implanted catheter. From literature review, the catheter migrated peripherally an average of 20 mm on the erect chest radiographs. In this study, we want to verify the actual presentation of catheter movement within a vessel and try to find a quantitative catheter length model to recommend.From March 2012 to March 2013, 346 patients were included into this prospective cohort study. We collect clinical data from medical record and utilized picture archiving and communication system to measure all image parameters. Statistical analysis was utilized to identify the risk factors for catheter migration.The nonmigration group had 221 patients (63.9%); 67 (19.4%) patients were classified into the peripheral migration group; and 58 (16.8%) patients were classified into the central migration group. Patients with short height (P = 0.03), larger superior vena cava (SVC) diameters at the brachiocephalic vein confluence site (P = 0.02), and longer implanted catheter length (P = 0.0004) had greater risks for central migration. We utilized regression curve for further analysis and height (centimeters)/10 had moderate correlation distances from the entry vessel to the carina.Although intravascular movement of catheter was exist in implanted catheter, the intraoperative fluoroscopy could provide accurate catheter tip location in 63.9% patients. Additional length of catheter implantation seems unnecessary in 80.6% patients. Patients with short height, larger SVC diameters at the brachiocephalic vein confluence site had greater risk for catheter central movement. Height/10 may be consider as reference length of implantation for inexperience surgeon and precise implantation length could be adjust under guidance of fluoroscopy.

Determination of Implant Length in Maxillary Anterior Region

Determination of Implant Length in Maxillary Anterior Region

Influence of the length and location of implants on distal extension removable partial dentures: finite element analysis

#35, 36, 37이 소실된 시상절단면의 후방연장모형과 가철성 국소의치를 기본모형으로 사용했다. NX 9.0으로 7개의 모델을 디자인했다. 모델 A, B, C에서 각각 11, 6, 4 mm 길이의 임플란트가 #37 인공치 하방에 위치 되었다. 모델 D, E, F에서 각각 11, 6, 4 mm의 임플란트가 #36 인공치 하방에 위치되었다. 모델 G는 임플란트가 없었 다. 수직하중(250 N)을 #36의 중심와에 가했고, 유한요소 분석프로그램을 이용해 von Mises stress와 변위를 관찰했다.

Otto Aufranc Award: Large Heads Do Not Increase Damage at the Head-neck Taper of Metal-on-polyethylene Total Hip Arthroplasties.

Fretting and corrosion at head-neck junctions of total hip arthroplasties (THAs) have been associated with adverse local tissue reactions in patients with both metal-on-polyethylene (MoP) and metal-on-metal (MoM) prostheses. Femoral head size contributes to the severity of fretting and corrosion in large-diameter MoM THAs, but its impact on such damage in MoP THAs remains unknown. (1) Is femoral head size associated with increased fretting or corrosion at the head-neck junction in MoP total hips? (2) Is duration of implantation associated with increased fretting or corrosion? The severity of fretting/corrosion on surfaces of head tapers and stem trunnions was visually examined in 154 MoP THAs retrieved as part of 3282 revision surgeries performed at our institution between January 1, 2007, and December 31, 2013. Fretting and corrosion damage were subjectively graded by two independent observers on a 1 to 4 scale, and their relations to head size, alloy combinations, taper/trunnion design, length of implantation (LOI), and location were investigated. Differences in scores never exceeded one grade, and this occurred in only 17% of examined implants. With the available implants, the study provided 88% power to detect differences of 0.5 in fretting or corrosion scores in these analyses. Fretting and corrosion of the tapers and the trunnions were not affected by head size (p = 0.247, p = 0.471, p = 0.837, and p = 0.868, respectively), although taper/trunnion design affected taper fretting (p = 0.005) and corrosion (p = 0.0031) and trunnion fretting (p = 0.0028). Head taper fretting (observed in 73% of heads) increased with LOI, but head taper corrosion (noted in 93% of heads) was not affected. Trunnion fretting (observed in 86% of stems) was more severe in mixed-alloy combinations and with increased LOI and was more severe proximally. Trunnion corrosion (noted in 72% of stems) was also location-dependent with greater corrosion distally. Fretting and corrosion are regular occurrences in MoP THAs, but neither damage type was related to femoral head size. Conversely, taper design, LOI, and alloy combination affected the severity of both fretting and corrosion. Although it has been suggested that trunnion corrosion seen in MoP bearings is a function of larger diameter heads, our data suggest that larger femoral heads may be used for increased damage at the modular junction of MoP THAs.

Cortical Bone Augmentation Versus Nerve Lateralization for Treatment of Atrophic Posterior Mandible: A Retrospective Study and Review of Literature.

We sought to assess implant success/survival/failure rate following cortical autogenous tenting technique (CATT) versus inferior alveolar nerve transposition (IANT) in the posterior mandible. Patients who underwent these two procedures between 2007 and 2011 were analyzed. CATT was performed using lateral ramus block graft and implants were inserted simultaneously or after 4 to 6 months. In IANT, implants were placed simultaneously after nerve transposition with or without mental foramen involvement. Data regarding marginal bone level (MBL), pus discharge (PD), neurosensory dysfunction (NSD), implant mobility, and failure were collected. Success rate was measured based on Pisa Consensus. Independent sample t-test with a significance level of 0.05 was used to compare implant dimensions and MBL changes between the two techniques. A total of 118 patients with a mean age of 54.85 years were included. The mean follow-up after CATT and IANT was 37.97 and 18.51 months, respectively. The overall survival and success rates of dental implants in the CATT group were 98.73% and 71.52%, respectively. The corresponding values for IANT subjects were 98.74% and 94.56%, respectively. Implant length and diameter in IANT group were significantly longer and wider than implants used after CATT (p value < .001). MBL changes in both techniques were less than 1 mm (p value = .79). Two cases of NSD, seven PD, and two implant failures were found in the CATT group. For IANT patients, seven permanent NSD, two PD, two implant failures, and one mandibular fracture were documented. Both techniques had implant survival rates similar to implants placed in unaltered bone. A higher implant success rate, albeit with higher incidence of long-lasting nerve damage, was observed in the IANT group.

PD26-06 IMPLANT LENGTH – BASELINE CHARACTERISTIC CORRELATIONS

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Surgical Therapy I1 Apr 2015PD26-06 IMPLANT LENGTH – BASELINE CHARACTERISTIC CORRELATIONS Nelson Bennett, Anthony Bella, Gerard Henry, Edward Karpman, Will Brant, LeRoy Jones, Bryan Kansas, Tobias Kohler, and Mohit Khera Nelson BennettNelson Bennett More articles by this author , Anthony BellaAnthony Bella More articles by this author , Gerard HenryGerard Henry More articles by this author , Edward KarpmanEdward Karpman More articles by this author , Will BrantWill Brant More articles by this author , LeRoy JonesLeRoy Jones More articles by this author , Bryan KansasBryan Kansas More articles by this author , Tobias KohlerTobias Kohler More articles by this author , and Mohit KheraMohit Khera More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.1082AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The “Prospective Registry of Outcomes with Penile Prosthesis for Erectile Restoration” (PROPPER) is a large, multi-institutional, prospective clinical study. There is a paucity of data regarding the factors that contribute to penile prosthesis size. Co-morbid conditions and demographic data with implanted penile prosthesis size were correlated. METHODS The PROPPER registry prospectively evaluates outcomes in men undergoing penile prosthesis implantation. Men completed baseline questionnaires prior to prosthesis implantation and at 12 months. Demographic, etiology of ED, duration of ED, co-morbid conditions, and pre-operative penile length (flaccid and stretched), operative technique, implant type and length, duration of surgery were complied. Pearson correlation coefficient was generated for length of implanted penile prosthesis vs. comorbid conditions /demographic data. RESULTS 849 men underwent implantation of IPP at 11 study sites. One of patient with missing implant length was excluded. All AMS IPP types were included in the analysis. Comorbidities were CV disease (32.1%), DM (13.4%), and PD (11.9%). Primary etiology of ED: RP (29.0%), CV Disease (20.3%), DM (21.4%), Other (16.1%), PD (9.8%), and Priapism (1.2%). Mean duration of ED is 6.8 ± 4.6 years. Pearson Correlation was weakly negatively correlated with White/Caucasian (r = -0.13; p=0.0002), RP (r = -0.13; p=0.0001), concomitant presence of PD (r = -0.08; p=0.0146), venous leak (r = -0.08; p=0.0149), and SUI (r = -0.15; p<0.0001). Implant length was weakly positively correlated with Black/AA men (r = 0.27; p≤0.0005), CV disease (r = 0.13; p≤0.0005) and stretched penile length (r = 0.26; p<0.0001) There is a moderate positive correlation with flaccid penile length (r =0.33; p<0.0001). CONCLUSIONS Implanted penile cylindrical length is significantly negatively correlated with White/Caucasian ethnicity. History of RP and presence of SUI are also strongly negatively correlated with implant length. Positive correlates include Black/AA ethnicity, CV disease, preoperative stretched penile length, and flaccid penile length. There does not appear to be a significant correlation with diabetes or duration of ED. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e568 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nelson Bennett More articles by this author Anthony Bella More articles by this author Gerard Henry More articles by this author Edward Karpman More articles by this author Will Brant More articles by this author LeRoy Jones More articles by this author Bryan Kansas More articles by this author Tobias Kohler More articles by this author Mohit Khera More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Corrosion and Fretting of a Modular Hip System: A Retrieval Analysis of 60 Rejuvenate Stems

Femoral stems with dual-taper modularity were introduced to allow independent control of length, offset, and version. Corrosion and fretting related to micromotion at the neck-stem junction are thought to stimulate an adverse local tissue reaction (ALTR). Analysis of 60 consecutively retrieved modular-neck stem implants (Rejuvenate, Stryker) revised primarily for ALTR was done to determine the variables influencing corrosion and fretting patterns at the neck-stem interface. Taper damage evaluation was performed with stereomicrocopic analysis with two observers. Evidence of fretting and corrosion was seen at the neck-stem taper in all implants, including three implants revised for periprosthetic fractures within four weeks of the index surgery indicating that this process starts early. Femoral stems paired with the long overall neck lengths had significantly higher corrosion scores. Correlation of the corrosion severity at particular locations with the length of implantation suggests that the neck-stem junction experiences cyclic cantilever bending in vivo. The positive correlation between the length of implantation and fretting/corrosion scores bodes poorly for patients who still have this implant. Scanning electron microscopy on a subset of specimens was also performed to evaluate the black corrosion material. We strongly urge frequent follow-up exams for every patient with this particular modular hip stem.

Influence of mefloquine administration during early pregnancy on rat embryonic development

Mefloquine (MQ) is a potent effective antimalarial drug against multiple drug-resistant Plasmodium falciparum. It has been proved that MQ can be given safely during the second and third trimesters. However, there is very limited information on the drug safety during the first trimester. The aim of the present work was to investigate the embryotoxicity and teratogenicity of MQ during critical periods of early development. Wistar rats were orally administered with a single dose of MQ (45 mg/kg bwt or 187 mg/kg bwt) on the 1st, 6th or 13th days of pregnancy. Cyclophosphamide (CPA) was chosen as a positive control. On the 21st day of gestation, standard parameters of reproductive performance and fetal examination were estimated. Malondialdehyde (MDA) level, glutathione reductase activity and glutathione (GSH) content were evaluated in placenta and liver homogenates of mothers and fetuses. The results indicated that MQ did not adversely affect the number of implantation, resorption, litter size and fetal body weight and length. Only groups treated with MQ on the 1st day of gestation exhibited significant decrease in fetal body weight. Examination of fetuses for external, visceral and skeletal changes showed minimal variations involving extension of lateral brain ventricles and renal pelvis and signs of delayed ossification. These variations were accompanied with significant elevation of MDA level and reduction of GSH content of fetal liver. Prenatal exposure to MQ at early pregnancy did not cause any embryolethal or teratogenic effect. It could slightly exacerbate minor variations.

Effect of Implant Diameter and Length on Stress Distribution for Titanium and Zirconia Implants by Using Finite Element Analysis (FEA)

Purpose: The purpose of this study was to analyze stress distribution patterns in implant restorations created in different length and diameter made of titanium and zirconia by using three dimensional finite element analysis (FEM) with straight and 15° angled abutment. Materials and Methods: For titanium models; Ti-6Al-4V for implant fixture, connection element and abutments (straight and 15° angled abutment), yttrium tetragonal zirconium polycrystal (Y-TZP) for zirconium framework, Felds phatic porcelain for superstructure material and for zirconia models; Y-TZP for implant fixture, connection element, abutments (straight and 15° angled abutment) and zirconium framework, Felds phatic porcelain for superstructure material were used. The implants and their superstructures were modeled using CAD software Creo Elements-Pro5.0 and the mandibula was modeled using MIMICS 13.1 software. Optimum finite element modelled was obtained using 3-matic segmentation of MIMICS. The solid models of mandibular incisors were transferred to mesh model in FEM (ANSYS/Workbench 12.1) to analyze. The models simulated implants were placed in vertical position in the lost incisor of anterior mandible. First model simulated the titanium and zirconia implants with a diameter of 3.8 mm and lengths of 9.0 mm, 10.5 mm, 12.0 mm and 15.0 mm for each model. Second model simulated titanium and zirconia implants with a diameter of 4.6 mm and lengths of 9.0 mm, 10.5 mm, 12.0 mm and 15.0 mm for each model. Third model simulated titanium and zirconia implants with a diameter of 5.8 mm and lengths of 9.0 mm, 10.5 mm, 12.0 mm and 15.0 mm for each model. This process was repeated for implants with 15° angled abutment. Loading of implants, respectively in an axial, a lingual and a mesiodistal direction with average masticatory forces of 114.6 N, 17.1 N and 23.4 N simulated in an oblique direction. The values of equivalent Von Mises Stress at the implant-bone interface were calculated for all variations using finite element analysis. Results: A comparison between titanium and zirconium implants with maximum stress for implants of the same length but different diameters, same diameters with different lengths and straight and 15° angled abutment showed nearly similar variances. Conclusion: With in the limitations of this study, increasing implant diameter is better than decreasing implant diameter both for titanium and zirconium models but raising implant length is worse than decreasing implant length with applied masticatory forces.

Does matching relation exist between the length and the tilting angle of terminal implants in the all-on-four protocol? stress distributions by 3D finite element analysis.

PURPOSETo explore whether there is matching relation between the length and the tilting angle of terminal implants in the All-on-Four protocol by studying the effects of different implant configurations on stress distributions of implant, bone, and framework.MATERIALS AND METHODSFour implants were employed to support a full-arch fixed prosthesis and five three-dimensional finite element models were established with CT images, based on the length (S and L) and distal tilt angle (0°, 30° and 45°) of terminal implants for an edentulous mandible, which named: Tilt0-S, Tilt30-S, Tilt30-L, Tilt45-S and Tilt45-L. An oblique 240 N was loaded at second molar. The von Mises Stresses were analyzed. The implants were consecutively named #1 to #4 from the loading point.RESULTS1) Tilt0-S had the greatest stress on the implants, with the other groups exhibiting variable reductions; the four implants of Tilt45-L demonstrated the greatest reduction in stress. 2) Tilt0-S had the greatest stress at bone around #1 implant neck, and Tilt45-L exhibited the least stress, which was a 36.3% reduction compared to Tilt0-S. 3) The greatest stress in the framework was found on the cantilevers distal to #1 implant. Tilt45-S exhibited the least stress.CONCLUSIONMatching different length and tilting angle of the terminal implants led to variable stress reductions on implants, bone and the superstructure. By optimizing implant configuration, the reduction of stress on implants and surrounding bone could be maximized. Under the present condition, Tilt45-L was the preferred configuration. Further clinical testings are required.

The initial stability of dental implant with horizontal plate (An in vitro study)

The Initial (primary) stability is one of the factors that play an important role in the success of the dental implants. The purpose of this study was to evaluate the initial stability of dental implant with horizontal plate by using five analytical tests: insertion torque, removal torque, resonance frequency analysis, push-in test and pull-out test. Materials and methods: Two different lengths of dental implants (5mm and 10mm) were tested in this study; each dental implant was 4mm in diameter with a square threads shape of 1mm pitch and 0.5mm depth. The crestal area was 4.2mm diameter contained a right angle margin circumferential ring while the apical area was tapered with two self-tapping grooves. In this study, the initial stability of dental implants' design was compared with initial stability of dental implants of the same dimensions and design that engage horizontal plates of 1.5mm thickness at the apical part. All dental implants were implanted into a solid rigid polyurethane foam blocks (artificial bone) of 0.48g/cm3 density and tested by the five initial stability tests. Each test was done with forty samples (twenty samples of 5mm length and twenty samples of 10mm length). Results: The statistical analysis was performed and the result showed that there was very highly significant difference between dental implants with the horizontal plates and dental implants without the horizontal plates of both 5mm and 10 mm lengths in four initial stability tests which were insertion torque, removal torque, push-in test and pull-out test. The statistical analysis of the resonance frequency analysis showed that there was non-significant difference between dental implants with the horizontal plates and dental implants without the horizontal plates of both lengths. Conclusion: These results implied that the dental implants with the horizontal plates had better primary stability compared with the dental implants without the horizontal plates confirming that the horizontal plates enhanced the primary stability of the dental implants.

Consecutive unsplinted implant-supported restorations to replace lost multiple adjacent posterior teeth: A 4-year prospective cohort study

Objective. The aim of this study was to investigate the various events occurring in unsplinted implant restoration in posterior jaws during a period of 4 years. Materials and methods. From August 2008 to April 2009, eight volunteers (three men and five women) who had two or more consecutively missing teeth received 20 implants in posterior maxillae and mandibles. Unsplinted single crowns were delivered to each implant. For the 4-year follow-up periods, patients were enrolled in a maintenance schedule at 1, 3, 6, 12, 24, 36 and 48 months. The data, including a questionnaire, radiography, mobility and probing were recorded on regular check-ups. Results. A total of 20 implants in eight patients were followed up for 48 months, showing a 100% survival rate. Mean marginal bone loss around implants was 0.26 mm. Statistical analysis revealed insignificant correlation between metal-ceramic and zirconia-ceramic crowns and among implant lengths (8.5 mm, 10 mm and 11.5 mm). Mean probing depths were similar or insignificantly different, regardless of the materials used or length of implants. The most frequent complications, in decreasing order, were food impaction (65%) and porcelain chipping (45%), sensitivity (25%), pain (20%) and loose contact (15%). Compared with metal-ceramic crowns, zirconia-ceramic crowns showed more unfavorable cases of porcelain chipping (p = 0.017), pain (p = 0.007) and loose contact with an adjacent crown (p = 0.031). Conclusions. Within the limits of the sample size, this study showed that unsplinted implant-supported single restorations to replace consecutive posterior missing teeth may function well.

Occlusion on oral implants: current clinical guidelines

Proper implant occlusion is essential for adequate oral function and the prevention of adverse consequences, such as implant overloading. Dental implants are thought to be more prone to occlusal overloading than natural teeth because of the loss of the periodontal ligament, which provides shock absorption and periodontal mechanoreceptors, which provide tactile sensitivity and proprioceptive motion feedback. Although many guidelines and theories on implant occlusion have been proposed, few have provided strong supportive evidence. Thus, we performed a narrative literature review to ascertain the influence of implant occlusion on the occurrence of complications of implant treatment and discuss the clinical considerations focused on the overloading factors at present. The search terms were 'dental implant', 'dental implantation', 'dental occlusion' and 'dental prosthesis'. The inclusion criteria were literature published in English up to September 2013. Randomised controlled trials (RCTs), prospective cohort studies and case-control studies with at least 20 cases and 12months follow-up interval were included. Based on the selected literature, this review explores factors related to the implant prosthesis (cantilever, crown/implant ratio, premature contact, occlusal scheme, implant-abutment connection, splinting implants and tooth-implant connection) and other considerations, such as the number, diameter, length and angulation of implants. Over 700 abstracts were reviewed, from which more than 30 manuscripts were included. We found insufficient evidence to establish firm clinical guidelines for implant occlusion. To discuss the ideal occlusion for implants, further well-designed RCTs are required in the future.

Stress Distribution Around Single Short Dental Implants: A Finite Element Study.

Bone height restrictions are more common in the posterior regions of the mandible, because of either bone resorption resulting from tooth loss or even anatomic limitations, such as the position of the inferior alveolar nerve. In situations where adequate bone height is not available in the posterior mandible region, smaller lengths of implants may have to be used but it has been reported that the use of long implants (length ≥10 mm) is a positive factor in osseointegration and authors have reported failures with short implants. Hence knowledge about the stress generated on the bone with different lengths of implants needs scientific evaluation. The purpose of this study was to compare and evaluate the influence of different lengths of implants on stress upon bone in mandibular posterior area. A 3 D finite element model was made of the posterior mandible using the details from a CT scan, using computer software (ANSYS 12). Four simulated implants with lengths 6 mm, 8 mm, 10 mm and 13 mm were placed in the centre of the bone. A static vertical force of 250 N and a static horizontal force of 100 N were applied. The stress generated in the cortical and cancellous bone around the implant were recorded and evaluated with the help of ANSYS. In this study, Von Mises stress on a 6 mm implant under a static vertical load of 250 N appeared to be almost in the same range of 8 and 10 mm implant which were more as compared to 13 mm implant. Von Mises stress on a 6mm implant under a static horizontal load of 100N appeared to be less when compared to 8, 10 and 13 mm implants. From the results obtained it may be inferred that under static horizontal loading conditions, shorter implants receive lesser load and thus may tend to transfer more stresses to the surrounding bone. While under static vertical loading the shorter implants bear more loads and comparatively transmit lesser load to the surrounding bone.

Implant based differences in adverse local tissue reaction in failed total hip arthroplasties: a morphological and immunohistochemical study.

BackgroundAdverse local tissue reaction (ALTR) is characterized by periprosthetic soft tissue inflammation composed of a mixed inflammatory cell infiltrate, extensive soft tissue necrosis, and vascular changes. Multiple hip implant classes have been reported to result in ALTR, and clinical differences may represent variation in the soft tissue response at the cellular and tissue levels. The purpose of this study was to describe similarities and differences in periprosthetic tissue structure, organization, and cellular composition by conventional histology and immunohistochemistry in ALTR resulting from two common total hip arthroplasty (THA) implant classes.MethodsConsecutive patients presenting with ALTR from two major hip implant classes (N = 54 patients with Dual-Modular Neck implant; N = 14 patients with Metal-on-Metal implant) were identified from our prospective Osteolysis Tissue Database and Repository. Clinical characteristics including age, sex, BMI, length of implantation, and serum metal ion levels were recorded. Retrieved synovial tissue morphology was graded using light microscopy and cellular composition was assessed using immunohistochemistry.ResultsLength of implantation was shorter in the DMN group versus MoM THA group (21.3 [8.4] months versus 43.6 [13.8] months respectively; p < 0.005) suggesting differences in implant performance. Morphologic examination revealed a common spectrum of neo-synovial proliferation and necrosis in both groups. Macrophages were more commonly present in diffuse sheets (Grade 3) in the MoM relative to DMN group (p = 0.016). Perivascular lymphocytes with germinal centers (Grade 4) were more common in the DMN group, which trended towards significance (p = 0.066). Qualitative differences in corrosion product morphology were seen between the two groups. Immunohistochemistry showed features of a CD4 and GATA-3 rich lymphocyte reaction in both implants, with increased ratios of perivascular T-cell relative to B-cell markers in the DMN relative to the MoM group (p = 0.032).ConclusionOur results demonstrate that both implant classes display common features of neo-synovial proliferation and necrosis with a CD4 and GATA-3 rich inflammatory infiltrate. Qualitative differences in corrosion product appearance, macrophage morphology, and lymphocyte distributions were seen between the two implant types. Our data suggests that ALTR represents a histological spectrum with implant-based features.

Retrospective study of sintered porous-surfaced dental implants placed in the augmented sinus.

The purpose of this study was to analyze clinical and radiographic outcomes of sintered porous-surfaced dental implants placed in partially edentulous posterior maxillae. The study group consisted of 42 partially edentulous patients who received sinus augmentation using the lateral window technique or crestal approach at Catholic University Hospital of Daegu and one private clinic. The 42 patients received a total of 92 sintered porous-surfaced dental implants in the edentulous posterior maxillae. All implants were restored with fixed prostheses. Of the 92 implants, 17 implants were restored with individual (nonsplinted) crowns, while 75 implants were splinted to other implants. Panoramic views and periapical radiographs using the standardized long-cone paralleling technique were taken at the first visit, postoperatively, at the time of prosthesis seating, and at a follow-up visit. Survival rates of implants in relation to location, length, diameter, crown-to-implant (C/I) ratio, and type of prosthesis were investigated. Statistical data were analyzed using software with the chi-square test. Of the 92 implants, 8 (8.7%) were removed, and the cumulative survival rate was 91.3% after a maximum 9-year functional period (mean: 72.8 months; range: 11 to 107 months). There were no statistical differences in relation to the location of implants, C/I ratio, or type of prosthesis. However, there were statistical differences in relation to the length and diameter of implants. Average crestal bone loss was 0.68 mm at 1-year follow-up and 1.13 mm at final examination. All implants were inserted in the augmented maxillary sites. The cumulative survival rate of sintered porous-surfaced implants in posterior maxillae was 91.3%. Sintered porous-surfaced implants showed satisfactory results in the edentulous posterior maxillae.

Photoelastic stress analysis of splinted and unitary implant-supported prostheses

Univ Estadual Paulista UNESP, Aracatuba Dent Sch, Dept Dent Mat & Prosthodont, BR-16016050 Sao Paulo, Brazil

Osseointegration of short titan implants: A pilot study in pigs

Reduced vertical bone level in the implantation area is often considered one of the limiting factors before implant insertion. Inserting implants of reduced length might be useful in order to avoid vertical bone augmentation prior to implantation. To the present day, no official guidelines exist as to the optimal length for these implants. It is nevertheless well known that the stability of an implant depends primarily on its osseointegration, which could otherwise be influenced by modifying implant surface texture. The aim of our study was to evaluate osseointegration in correlation with implant length and surface texture. Three different variations of titan implants (n=5) were compared: two types, each with an acid-etched and ceramic blasted surface, were inserted in the upper jaw of adult female minipigs at different lengths (tioLogic ST Shorty, 5mm length; tioLogic ST, 9mm length) and were compared to a control group (tioLogic ST, 9mm length, ceramic blasted surface). Eight weeks after unloaded healing, bone tissue specimens containing the implants were processed, stained with Masson–Goldner-trichrome and analyzed histologically. Regardless of implant length and surface texture, new bone formation with no signs of inflammation could be detected in the area of the threads. Implants with a modified surface showed no statistically significant difference in bone-implant-contact (BIC) (tioLogic ST Shorty, 56.5%; tioLogic©ST; 77.2%), but a statistically significant difference could be found, when the 9mm implants were compared to the control group (BIC 48.9%). Surface modification could positively influence osseointegration as well as contribute to overcoming the adverse effects of length reduction.

A Four-Year Survival Rate Multicenter Prospective Clinical Study on 377 Implants: Correlations Between Implant Insertion Torque, Diameter, and Bone Quality

The purpose of this study was to evaluate the survival rate and incidence of prosthetic complications in 377 implants with a double octagon connection. Furthermore, the correlations among implant dimensions (diameter and length), bone quality, and insertion torque were investigated. A 4-year multicenter prospective clinical study was designed to evaluate the survival rate of 377 dental implants inserted in 189 patients between January 2004 and April 2010. After an average follow-up of 46 months, the implant survival rate was 99.7%, and the incidence of complication was 0.53%. Moreover, insertion torque was statistically related in a significant way to implant diameter. The connection system seemed to reduce the risk that the prosthetic component screw would loosen. Within the limits of this study, it was observed that a wider diameter corresponded to a higher implant primary stability. Implant length did not seem to be critical in obtaining higher primary stability.