Institut Straumann Research Articles

Comparison of microbial adhesion and biofilm formation on different orthodontic aligners

This study aimed to compare and evaluate time-dependent biofilm formation and microbial adhesion on 6 different clear aligner systems: Invisalign (Align Technology, San Jose, Calif), Clarity (3M ESPE Maplewood, Minn), ClearCorrect (Institut Straumann AG, Basel, Switzerland), Smartee (Smartee Denti-Technology, Shanghai, China), Orthero (Orthero, Istanbul, Turkey) and Graphy (Graphy Inc, Seoul, South Korea). Streptococcus mutans (ATCC 25175) and Lactobacillus acidophilus (ATCC 4356) were used to evaluate the microbial adhesion and biofilm formation on orthodontic clear aligners at the 0, 24, 48, 72, 96, 120, 168, and 240 hours. Two-way repeated measures analysis of variance (Greenhouse-Geisser) test and post-hoc Bonferroni T2 tests were used for statistical evaluation. The statistical significance level was set at P<0.05. It was found that more bacterial formation occurred on ClearCorrect than on Smartee at 120, 168, and 240 hours (P<0.05). It was observed more biofilm formation at 168 hours on Graphy than on Smartee (P<0.05). It was found that S mutans+ L acidophilus formed more biofilm at 120 and 168 hours on Graphy than on Invisalign (P<0.05). Elevated biofilm formation across all materials carries substantial clinical implications. Orthodontists and patients should remain aware of the increased risk of microbial colonization with extended aligner usage.

Immediately versus early placed bone-level-tapered implants supporting all-ceramic crowns on titanium base abutments: 1-year radiographic and pink esthetic outcomes of a multicenter pilot RCT.

Aim of this study was to assess survival rates, radiographic, and pink esthetic outcomes of a bone-level-tapered (BLT) implant following immediate or early implant placement. Patients in need of tooth extraction and one implant in the anterior or premolar area were recruited in five centers. Patients were randomly assigned to the immediate or early placement protocol. Implants were restored with all-ceramic crowns cemented to titanium-base-abutments. Radiographic bone levels, implant stability quotient (ISQ), and pink esthetic outcomes were assessed. Data were analyzed descriptively. Level of significance was set at 0.05. Differences between groups were tested using Wilcoxon-signed-rank and Mann-Whitney-U test as nonparametric tests. A total of 60 patients received 60 BLT implants (Institut Straumann). At 12-months, 59 implants (98.3%) were osseointegrated. The mean distance from implant shoulder to first bone-to-implant contact was 0.15 ± 0.59 mm without significant differences between the groups. Median ISQ values increased from 75.5 to 78.5. A mean buccal recession of 0.1 ± 0.70 mm occurred with no difference between groups. The mean papilla height gain in both groups was 0.5 ± 1.47 mm mesially and 0.4 ± 1.36 mm distally. After 1 year, immediately and early placed BLT implants exhibit similar bone level changes, ISQ values, and pink esthetic outcomes. The present research contributes to the knowledge on clinical outcomes of immediately and early placed BLT implants restored with buccally microveneered ceramic single crowns out of two different ceramic materials. The research shows that similar esthetic and radiographic outcomes can be reached by means of immediate implant placement compared to the conventional early placement protocol. The improvement of esthetic soft-tissue parameters over time was shown for both implant placement protocols.

Evaluation of Porcine Collagen Membranes Used with Guided Bone Regeneration for Critical Defects: A Histological, Histomorphometric, Immunohistochemical, and Inflammatory Profile Analysis.

The objective of this study was to compare the effectiveness of two porcine collagen membranes of different origin used for guided bone regeneration procedures. Resorbable collagen membrane from porcine dermis (Bio-Gide, Geistlich Pharma AG, Wolhusen, Switzerland) and resorbable collagen membrane from porcine pericardium (Jason, Institut Straumann AG, Peter Merian-Weg, Switzerland) were evaluated; histological, histometric, immunohistochemical, and inflammatory profile analyses were performed. The study was carried out on critical defects created in the calvaria of 72 rats (Rattus norvegicus albinus, Wistar variety) divided into three groups: coagulum group (Co), porcine pericardium group (JS), and porcine collagen group (BG). The defects were filled with clot, over which the membranes were placed. The animals were euthanized 7, 15, 30, and 60 days after surgery. The Shapiro-Wilk test was used to assess data distribution. Analysis of variance (ANOVA) and the Bonferroni multiple comparison test were used to compare the differences across the mean values of the variables. Nonparametric tests, Mann-Whitney and Wilcoxon W, were used for the quantitative analysis of the inflammatory profile. A significance level of 5% (p < 0.05) was adopted with a confidence interval of 95%. SPSS software version 2.0 was used. A total of 1,008 analyses were performed on 288 histological slides. It was noted that both types of collagen membranes used in this study were effective for the guided bone regeneration procedure, with a greater proportion and thickness of bone formation among recipients of the BG (735 points, p = 0.021). This membrane also had greater permeability (62.25). The animals in the JS group, which received the porcine pericardial membrane, showed early and accelerated bone formation from early bone tissue, milder osteopontin and osteocalcin levels, and greater inflammatory reaction (86.4). The collagen membrane from porcine dermis demonstrated a more orderly and physiological repair process, while the porcine pericardial membrane presented a more accelerated repair process that did not remain constant over time.

Assessment of Micro-Gap in Hybrid Abutment-Crowns Fabricated with Different Materials

Objective: The aim of this in vitro study is to evaluate the micro-gap changes in three dimensions after thermodynamic loading between hybrid abutment crowns made of different materials and implants with internal conical connection.&#x0D; Methods: A total of 10 morse cone connection implants (Straumann Bone Level Implant, Institut Straumann AG, Basel, Switzerland) were used. In this study, two study groups were formed using lithium disilicate glass-ceramic (LD) and polymethyl methacrylate (PMMA) in hybrid abutment-crown production (n=5). Hybrid abutment-crowns were fabricated by CAD/CAM system. Hybrid abutment crowns were designed and manufactured digitally. A 4-month of clinical cycle was applied to the samples in the chewing simulator. The micro-gap at the implant- abutment interface was visualized with micro-CT before and after thermodynamic loading. Micro-gap change was determined using these obtained images. For comparisons, independent t-test was used.&#x0D; Results: When comparing the micro-gap volumes before and after aging, no significant difference was observed between the LD and PMMA groups. The micro-gap increase after loading was 0.68 ±0.209 in the LD group and 0.45 ±0.373 in the PMMA group. Although the increase was higher in the LD group, there is no statistically significant difference between two groups.&#x0D; Conclusion: he micro-gap in the interface of implants and hybrid abutment crowns increased after aging. Hybrid abutment-crown material affected the micro-gap increase, but it was not statistically significant.

Immediate Implant Placement in the Esthetic Zone Using a Novel Tapered Implant Design and a Digital Integrated Workflow: A Case Series.

The purpose of this case series was to assess the application of a novel self-cutting, tapered implant (Straumann® BLX, Institut Straumann AG, Basel, Switzerland) in combination with a digital integrated prosthetic workflow for the immediate placement and restoration. Fourteen consecutive patients, requiring replacement of a single hopeless maxillary or mandibular tooth, meeting the clinical and radiographic indication criteria for immediate implant placement, were treated. All cases followed the same digitally-guided procedure of extraction and immediate implant placement. Immediate temporization with full contoured screw-retained provisionals was performed using an integrated digital workflow. After implant placement and dual-zone bone and soft tissue augmentation, connecting geometries and emergence profiles were finalized. The average implant insertion torque was 53.2 ± 14.9 Ncm and ranged between 35 and 80 Ncm, allowing immediate provisional restoration in all cases. Final restorations were delivered three months after implant placement. An implant survival rate of 100% was observed at the 1-year recall after loading. The results of this case series suggest that immediate placement of novel tapered implants and immediate provisionalization using an integrated digital workflow can result in predictable functional and esthetic results for the immediate transition of failing single teeth in the esthetic area.

Evaluation of one-piece zirconia dental implants: An 8-year follow-up study

ObjectivesLong-term studies of modern zirconia implants are still insufficient. This prospective 8-year follow-up study investigated one-piece zirconia implants.Materials and methodsPatients who had received a one-piece zirconia dental implant (PURE ceramic implant, Institut Straumann GmbH, Basel, Switzerland) were included in this study. Next to the implant survival and success rates, the radiographic and clinical implant parameters were assessed.ResultsThe overall survival rate of 67 zirconia implants in 39 patients was 100%. The overall success rate was 89.6%. Around the immediate zirconia implants, the success rate was 94.7%, and around the delayed implants, 87.5%. The immediate implants showed a significantly higher bone crest compared to the delayed implants (p = 0.0120). According to the pink esthetic score, the immediate implants revealed more favorable esthetic results compared to the delayed implants after an 8-year follow-up (p = 0.0002).ConclusionsAfter 8 years, the one-piece zirconia implants presented an 89.6% success rate. Regarding the timing of implantation, in individual cases, immediate implantation can have slight advantages over delayed implantation.Clinical relevanceImmediate implants can also be considered for zirconia implants and should not be excluded on principle.

Reverse scan body: A complete digital workflow for prosthesis prototype fabrication.

To assess the accuracy of fit of prosthesis prototypes fabricated via a complete digital workflow protocol with a reverse scan body skipping intraoral scanning for implant data acquisition. A maxillary stone cast with four multiunit abutment implant analogs (Screw-Retained Abutments, Institut Straumann AG, Basel, Switzerland) with adequate anteroposterior spread simulated a common clinical patient situation. This stone cast served as the master cast and an interim screw-retained prosthesis was fabricated on it. Novel reverse scan bodies were connected to the interim prosthesis, and extraoral scanning was performed with a white light intraoral scanner. The produced standard tessellation language (STL) files were then imported to computer-assisted design software and after the digital design, the STL file was exported to a computer-assisted machining milling machine and a three-dimensional (3D) printer to produce a total of 50 milled and 50 printed fixed complete denture prototypes, respectively. Two clinicians assessed the accuracy of fit of each digitally fabricated prosthesis prototype on the master cast, utilizing the screw-resistance test and radiographic evaluation. Out of the 100 prototypes, 94% (94/100) were fitting accurately. Fisher's exact test was used to test the difference among the groups. The test revealed statistically significant results (p=0.027). Out of the 50 digitally fabricated milled prosthesis prototypes, 50 (100%) presented with accurate fit under in vitro assessment. Out of the 50 digitally fabricated 3D printed prototypes, 44 (88%) presented with accurate fit under in vitro assessment. Accurately fitting digitally fabricated prosthesis prototypes can be milled after extraoral scanning with reverse scan bodies without intraoral implant data acquisition.

Esthetic and clinical outcomes after immediate placement and restoration: Comparison of two implant systems in the anterior maxilla-A cross-sectional study.

To assess the esthetic and clinical performance of a novel self-tapping implant system for single-tooth restorations in the esthetic zone after immediate placement and provisionalization. This cross-sectional study included 52 patients contributing a total of 52 immediately placed and restored implants with ≥12 months after functional loading, comparing two different implant systems: Straumann® BLX (Institut Straumann AG, Basel, Switzerland; 25 patients) and Ankylos® (Dentsply Sirona, Hanau, Germany; 27 patients). As the primary outcome measure, peri-implant tissue esthetics were assessed by means of pink esthetics score (PES) rated by three independent clinicians. Moreover, as secondary outcome measures, the peri-implant tissue health was assessed by means of bleeding on probing, probing depth, and suppuration. Apart from that, the modified plaque index, keratinized mucosa width, and the presence of mucosal recessions were also assessed. When clinical signs suggested the possibility of peri-implantitis, radiographs were indicated to assess progressive bone loss. The mean PES ratings were 12.10± 1.10 for Ankylos versus 11.2± 1.86 for BLX, both achieving good esthetic results without significant differences (p= 0.143). There were no differences among most clinical parameters (plaque, bleeding on probing, probing depth, peri-implant mucosal recession), although peri-implant mucositis was present in one-third of the cases. The inter-rater agreement on esthetics was not significant (p < 0.250). Within the limitations of the present study, it was concluded that the use of either BLX or Ankylos implant systems was associated to comparable peri-implant health and good pink esthetic outcomes during immediate implantation and restoration protocols, for at least 12 months.

An in vitro evaluation of 2 methods for retrieving fractured abutment screw fragments from the intaglio of 4 different implant systems

Statement of problemWhen an abutment screw fractures, there is no standardized technique for retrieving it from the intaglio of the dental implant. PurposeThe purpose of this in vitro study was to assess the relative efficacy of a commercially available screw fragment retrieval kit with a range of standard dental instruments in regard to success and retrieval time. In addition, the effects of other variables on the success rate of screw fragment retrieval and the retrieval time required were also investigated. Finally, the integrity of the intaglio screw channel of the dental implant was also assessed following retrieval. Material and methodsThe abutment screws from 4 dental implant systems: Osseotite Certain, Ø4.1 mm (Zimmer Biomet); Osseotite External hexagonal connection micromini, Ø3.25 mm (Zimmer Biomet); Standard Plus Tissue Level, Ø4.8 mm (Institut Straumann AG); and Brånemark Mark III TiUnite, Ø4.1 mm (Nobel Biocare) had notches placed between the first and second coronal threads before being placed in their respective abutments, positioned in the dental implants (n=128), and tightened until the screws fractured. The dental implant specimens were placed in maxillary and mandibular casts at the lateral incisor and first molar sites on both sides. The casts were placed in mannequin heads on a dental chair and assigned to 2 experienced and 2 inexperienced operators who used 2 different retrieval kits to retrieve the screw fragments.Chisquared tests were used to determine the association between the success rate of screw fragment retrieval and the other factors recorded (α=.05), and a binary logistic regression was used to determine the association between the retrieval event and all of the independent variables. Regression models were developed to determine the factors effecting retrieval time. ResultsAn overall success rate of 88.3% was achieved for screw fragment retrieval. No statistically significant difference (P>.999) was found in the relative efficacy of the retrieval kits. Univariate analysis identified a statistically significant association (P<.01) in the success of abutment screw fragment retrieval between the Osseotite Certain and the Osseotite External hexagonal connection micromini implant systems. Gamma regression analysis identified significant differences between the time taken to retrieve the screw fragments and the type of dental implant (P<.001), (P<.01). The time taken to retrieve screw fragments in the maxillary arch was significantly longer than for the mandibular arch (P<.05). ConclusionsThe commercially available screw fragment retrieval kit and the standard dental instruments were equally effective in retrieving the screw fragments. Less time was required to retrieve screw fragments in the mandibular arch than the maxillary arch. The level of experience of the operator had no effect on the ability to successfully retrieve fractured abutment screws.

Macroscopic Evidence of Surface Changes of Dental Implants After Insertion and Removal in Dense Bone: In Vitro Study.

Titanium and zirconium wear are discussed in the literature as contributing factors for mechanical complications. The purpose of this study was to evaluate if current implant designs present visible clinical evidence of surface damage after insertion and removal in dense bone and if these changes are comparable in titanium and zirconia implants. For this experimental in vitro and pilot study, four implant systems were evaluated. Astra Tech Implants (Dentsply Sirona), Nobel Biocare Implants (Nobel Biocare), Straumann Implants (Institut Straumann), and Zeramex Implants (Dentalpoint). Six implants of each group with similar lengths (between 10 and 11 mm) and diameters (between 4.0 and 4.5 mm) were used. Protocols for implant bed preparations in dense bovine bone disks represented type II bone density. The implants were inserted and removed to evaluate the changes experienced by their surfaces using a magnification compatible with 5× magnification of the clinical setting. The presence or absence of damage and type of damage were evaluated at the coronal, middle, and apical regions at higher magnification. The Cochran Q test for binary dichotomous samples was used for statistical comparisons. All the groups showed surface changes; titanium implants showed abrasion at the threads' flanks, and zirconia implants showed microfractures at the tip of the threads. Due to the insertion and removal of titanium and zirconia implants in dense bone, the flanks and tips of the implant threads will develop visible surface damage.

Transfer learning in a deep convolutional neural network for implant fixture classification: A pilot study.

PurposeThis study aimed to evaluate the performance of transfer learning in a deep convolutional neural network for classifying implant fixtures.Materials and MethodsPeriapical radiographs of implant fixtures obtained using the Superline (Dentium Co. Ltd., Seoul, Korea), TS III (Osstem Implant Co. Ltd., Seoul, Korea), and Bone Level Implant (Institut Straumann AG, Basel, Switzerland) systems were selected from patients who underwent dental implant treatment. All 355 implant fixtures comprised the total dataset and were annotated with the name of the system. The total dataset was split into a training dataset and a test dataset at a ratio of 8 to 2, respectively. YOLOv3 (You Only Look Once version 3, available at https://pjreddie.com/darknet/yolo/), a deep convolutional neural network that has been pretrained with a large image dataset of objects, was used to train the model to classify fixtures in periapical images, in a process called transfer learning. This network was trained with the training dataset for 100, 200, and 300 epochs. Using the test dataset, the performance of the network was evaluated in terms of sensitivity, specificity, and accuracy.ResultsWhen YOLOv3 was trained for 200 epochs, the sensitivity, specificity, accuracy, and confidence score were the highest for all systems, with overall results of 94.4%, 97.9%, 96.7%, and 0.75, respectively. The network showed the best performance in classifying Bone Level Implant fixtures, with 100.0% sensitivity, specificity, and accuracy.ConclusionThrough transfer learning, high performance could be achieved with YOLOv3, even using a small amount of data.

Differential Effects of Neurectomy and Botox-induced Muscle Paralysis on Bone Phenotype and Titanium Implant Osseointegration.

Metabolic bone is highly innervated by both sensory and sympathetic nerves. In addition to skeletal development, neural regulation participates in local bone remodeling, which is important for successful osseointegration of titanium implants. Neurectomy is a model used to investigate the lack of neural function on bone homeostasis, but the relative impacts of direct denervation to bone or denervation-induced muscle paralysis are less well defined. To investigate this difference, we used two nerve intervention models, sciatic and femoral neurectomy (SFN) v. botox-induced muscle paralysis (BTX) and assessed the resulting femoral bone phenotype and Ti implant osseointegration. Male Sprague Dawley rats (19) were randomly divided into three groups: implant control (n=5), SFN (n=7), and BTX (n=7). Ti implants (microrough/hydrophilic [modSLA], Institut Straumann AG) were placed in the distal metaphysis of each femur on day 24 post-SFN or BTX. Bone and muscle were examined on day 28 after implant insertion. Both nerve intervention models impaired osseointegration. MicroCT and histology indicated that both models had reduced trabecular bone formation. Only BTX reduced cortical bone formation and increased cortical bone porosity. BTX resulted in more bone loss characterized by the least trabecular and cortical bone, as well as osseointegration. Osteoblasts isolated from the tibia exhibited a model-specific phenotype when they were grown on Ti substrates in vitro. Neurectomy caused more severe muscle atrophy than botox injection. These results indicate that neural regulation directly modulates bone formation and osseointegration. Muscle paralysis modulated the effects of loss of neural inputs into bone, supporting the hypothesis that mechanical loading of bone is a factor in achieving successful osseointegration. The different effects of botox and neurectomy on bone phenotype indicated that the sensory and sympathetic nerves had a role in the osseointegration process.

Effect of additional reference objects on accuracy of five intraoral scanners in partially and completely edentulous jaws: An in vitro study

Statement of problemThe effect of additional reference objects on the accuracy of different intraoral scanners for partially and completely edentulous patients has not been investigated sufficiently. PurposeThe purpose of this in vitro study was to evaluate the effect of an additional reference object in the form of additional artificial landmarks on the trueness and precision of different intraoral scanners in partially and completely edentulous areas. Material and methodsPartially and completely edentulous models with 2 and 4 implants (BLT, RC, Institut Straumann AG), respectively, were used in the study. For the digital scan, scan bodies (CARES Mono Scanbody) were attached, and reference data obtained by using industrial scanners. Ten digital scans of the same model were made with each intraoral scanner: PRIMESCAN, TRIOS 3, TRIOS 4, Carestream 3600, and Medit. Then, additional artificial landmarks were attached, and 10 more intraoral scans were made with each device. Computer-aided design files of the scan bodies were aligned to obtain 3-dimensional surfaces with reference and test scanners. Trueness and precision of distance, angulations, and vertical shift between scan bodies were estimated. The Mann-Whitney Wilcoxon or Student 2-sample t test was applied to estimate statistically significant differences between groups (α=.05). ResultsIn the partially edentulous model, distance trueness mean ±standard deviation values ranged from −46.7 ±15.4 μm (TRIOS 3) to 392.1 ±314.3 μm (Medit) in models without additional artificial landmarks. When additional artificial landmarks were applied, trueness of distance mean ±standard deviation values ranged between −35 ±13 μm (TRIOS 4) and 117.7 ±232.3 μm (CARESTREAM). Trueness mean ±standard deviation values of angulation varied from −0.0 ±0.5 degrees (CARESTREAM) to 0.2 ±0.0 degrees (PRIMESCAN) without additional artificial landmarks and from 0.0 ±0.2 degrees (TRIOS 3) to 0.4 ±0.5 degrees (CARESTREAM) with additional artificial landmarks. Vertical shift trueness measurements varied from −108 ±47.1 μm (TRIOS 4) to 107.2 ±103.5 μm (Medit) without additional artificial landmarks and from −15.0 ±45.0 μm (CARESTREAM) to −86.9 ±42.1 μm (TRIOS 4) with additional artificial landmarks. The additional artificial landmark technique improved the trueness of all measured parameters for the 5 tested intraoral scanners. No statistically significant differences were found among models with or without additional artificial landmarks, except for Medit in all parameters and PRIMESCAN in angle measurements (P<.05). The best precision for distance was found with TRIOS 3 and with PRIMESCAN for angulation and vertical shift. Larger deviations were observed in the completely edentulous situation. The effect of additional artificial landmarks was limited when the accuracy parameters of digital scans were considered. ConclusionsScans with and without additional artificial landmarks of partially edentulous conditions scanned by any of the intraoral scanners tested did not influence precision and trueness, except for Medit i500 in the distance and vertical shift parameters and CARESTREAM3600 in vertical shift. Precision and trueness of digital scans of completely edentulous areas were affected, except for Medit i500 for distance, PRIMESCAN and TRIOS 4 for angle, and all systems except TRIOS 4 for vertical shift precision.

The influence of crown coverage on the accuracy of static guided implant surgery in partially edentulous models: An in vitro study

ObjectiveTo evaluate the influence of crown coverage of surgical guides on the accuracy of static computer-assisted implant surgeries (sCAISs) in different partially edentulous situations. MethodsAcrylic models with five types of partially edentulous situations were fabricated in this study. In coDiagnostiX software (Dental Wings, Montreal, Canada), surgical templates were designed and fabricated with reduced crown coverage (RCC), standard crown coverage (SCC) and extended crown coverage (ECC). Then, fully guided implant placement into the acrylic models was performed by dental surgeons with more than 10 years of experience. In total, 120 models and 120 guides were manufactured, and 168 bone-level Straumann replica implants (4.1 × 10 mm, Institut Straumann AG, Basel, Switzerland) were inserted. Postoperative implant positions were scanned (Trios 3, 3 shape, Copenhagen, Denmark) and compared with the preplanned virtual positions via coDiagnostiX (Dental Wings, Montreal, Canada). The angular, coronal and apical deviations were measured and analyzed to evaluate the accuracy of implant insertion. Statistical analysis was performed using one-way ANOVA and Tukey's test. ResultsFor single tooth missing situations, the RCC group was similar to the SCC group and ECC group in anterior sites. In premolar or molar sites, the SCC and ECC groups had no statistically significant difference (p > .05), while the RCC group had more coronal and apical deviation (p < .05). For multiple teeth missing situations, there was no difference among the RCC, SCC and ECC groups (p > .05). No difference was found among the five edentulous situations with different CCs (p > .05). ConclusionThe CC of templates can significantly affect the accuracy of guided surgeries when implants are inserted in a single gap at posterior sites. Templates with CC extended to the undercut line may be an optimal choice for static guided surgeries. Clinical significanceThe accuracy of static guided implant surgery can be influenced by the CC of templates, and proper CC with the guide covering extending to the undercut line may contribute to improved accuracy. CC should be taken into consideration when designing surgical templates.

P2. Use of semaphorin 3A for improving osseointegration of titanium implants in type 2 diabetes mellitus rats

<h3>BACKGROUND CONTEXT</h3> Type 2 diabetes mellitus (T2DM) is a systemic disease that can compromise osseointegration of metal implants; thus, technologies that can improve osteogenesis in T2DM patients are needed. Semaphorin 3A (3A) is a novel osteoprotective protein that has been reported to improve bone formation. Our goal was to assess 3A for potential clinical use. However, current T2DM rat models lack translatability to human conditions. It is important to clarify osseointegration in a more translational T2DM. For this study, we used the Zucker diabetic Sprague Dawley rat (ZDSD) as a more clinically relevant T2DM model. It is a polygenic model with an intact leptin pathway as in humans, and exhibits human-like type 2 diabetes progression. <h3>PURPOSE</h3> This study used grit blasted/acid etched (SLA) Ti implants (microrough/hydrophobic) in ZDSD rat femurs to determine if 3A can improve their osseointegration in T2DM. <h3>METHODS</h3> Thirty male, 15-week-old ZDSD rats (D, Charles River) and 24 aged-matched male Sprague Dawley rats (N, Charles River) were used (IACUC approved). Rats were paired fed with a high-fat diet (Purina 5SCA) until 70% of D rats turned diabetic (blood glucose >250mg/dL for a week) and switched to a normal diet (Purina 5008) for the rest of the study. Three weeks after turning diabetic, D rats were randomized to three groups: click hydrogel delivery vehicle (D GEL), hydrogel containing 3A (D 3A+GEL), hydrogel implanted and 3A injected separately (D i3A+GEL) with n=7. N rats were randomized to N GEL, N 3A+GEL, N i3A+GEL with n=8. Holes were created bilaterally in the metaphysis of distal femurs, and hydrogels were inserted in the hole by mixing PEG-N3 and PEG-DBCO crosslinker with either 0.9% sterile saline in GEL and i3A+GEL or with 6ug 3A in 3A+GEL. SLA implants (Institut Straumann AG) were inserted immediately into the holes after GEL. i3A+GEL had bilateral subperiosteal 3A injections (6ug/leg) at implant sites on day 3 and day 10 post-surgery. Rats were euthanized at 4 weeks postop. Bone phenotype and osseointegration of isolated fixed femurs were assessed by micro-computed tomography (microCT). Total bone to implant contact (BIC) was defined as the percentage of the implant surface in contact with newly formed bone. Evaluations of BIC were also performed separately for two subregions, the medullary (bone marrow BIC) and the cortical compartment (cortical BIC). Removal torque testing was performed with fresh, non-fixed femurs. <h3>RESULTS</h3> D GEL had less trabecular bone formation than N GEL. Cortical bones at metaphysis and mid-diaphysis were not affected by T2DM. D GEL had less total BIC and less bone marrow BIC but no difference in cortical BIC than N GEL. D 3A+GEL had less total BIC and cortical BIC than N 3A+GEL but bone marrow BIC in D 3A+GEL was the same as in N 3A+GEL. Similar results were observed between D i3A+GEL and N i3A+GEL. Maximum torque and torsional stiffness were less in D GEL than N GEL but not different between D 3A+GEL and N 3A+GEL or D i3A+GEL and N i3A+GEL. There was no significant difference in torsional energy among all groups. <h3>CONCLUSIONS</h3> T2DM reduced trabecular bone formation but did not affect cortical bone. Osseointegration was impaired in T2DM indicated by having less total BIC. Sema3A improved osseointegration in T2DM indicated by increased bone marrow BIC and increased mechanical properties of integrated bone tissues after sema3A delivered by hydrogel or local injection. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Analysis of the temperature variations in different implant systems with thermal imaging camera: An in vitro study on bovine ribs:

Aim The aim of this study was to evaluate the thermal variations during implant osteotomy with three different implant systems at different drilling speeds in the bovine bone. Also, we aimed to explore the period over 47°C during drilling with each drill of each implant system. Materials and methods Using bovine ribs, 3 implant systems were compared: Implantium® (Dentium, Seoul, Korea), Straumann® (Institut Straumann AG, Basel, Switzerland), and Anyridge® (Anyridge, Seoul, Korea). With increasing diameter drills (Implantium (4 drills); Straumann (4 drills); Anyridge (5 drills)) at three drilling speeds (150, 250, and 400 rpm) implant bed preparations were performed with a conventional approach. Maximum heat generated and the duration of the generated heat over 47°C in each drill of each implant system at different drilling speeds were measured, and results were compared. Results Significant increase in temperature was observed for the majority of the drills at 250 rpm (except D-I2, S-4.2, M-2) and 400 rpm (except M-2) when compared to the 150 rpm (p<0.05). However, between 250 and 400 rpm temperature variations did not follow a uniform trend and showed differences based on the drill used. Maximum generated heat observed in D-I2 (400rpm) as 59.37°C for Implantium system, in S-3.5 (250 rpm) as 58.71°C for Straumann system, in M-2.8 (400rpm) as 75.67°C Anyridge system. For all measurements Implantium and Strauman systems exhibit lower variations in temperature when compared to the Anyridge system. The period over critical threshold also below the limit of 1 minute for all measurements. The maximum duration of over 47°C was observed for the drill M-2.8 (400rpm) as 15.63 seconds. Conclusion It can be concluded based on the results of the study that when considering the temperature increase and the time spent for preparation of implant site over the critical threshold by the evaluated systems at different speeds without irrigation was in safe limit clinically. Further in vitro and in vivo studies by considering more parameters required to be conducted to determine the optimum drilling parameters for each implant system in clinical practice.

A Comparison of the Autogenous Bone Collection Capacity of Two Bur Drill Systems Used in Implant Surgery with Different Bur Diameters and Lengths at Different Drilling Speeds: An In Vitro Study.

The aim of this study was to compare the bone collection capacity of bur drill systems used in implant surgery with different diameters, lengths, and drilling speeds. This study was performed on bovine ribs. Two bur drill systems were studied: Implantium (Dentium) and Straumann (Institut Straumann). The groups were divided into subgroups according to the bur diameter. As a result, there were four Implantium subgroups (3.3, 3.8, 4.3, and 4.8 mm) and three Straumann subgroups (3.3, 4.1, and 4.8 mm). In addition, for each bur diameter, the bone collection capacities of the drill systems were evaluated at three different drilling speeds (150, 250, and 400 rpm) and two bur lengths (10 and 12 mm). The diameter, length, and speed changes were performed, and the results were compared between the two drill systems. The mean bone weight collected by using the Straumann burs was higher than that of the Implantium burs at each drilling speed and bur length. Using the Straumann system, the different drilling speeds/lengths of the burs had no impact on the bone collection capacity, irrespective of the bur diameter (P > .05). However, the drilling speeds/lengths of the Implantium system resulted in a statistically significant difference in the same diameters (P < .05). Both bur systems were suitable for autogenous graft collection for bone grafting in implant surgery, but the Straumann burs were more successful than the Implantium burs.

Clinical performance of narrow-diameter titanium\u2013zirconium implants in immediately loaded fixed full-arch prostheses: a 2-year clinical study

ObjectivesThe aim of this study was to evaluate the outcomes of immediate fixed full-arch prostheses supported by axial or tilted narrow-diameter Ti-Zr implants (3.3 mm) (Roxolid®, Institut Straumann® AG, Basel, Switzerland) (NDIs) in combination with standard-diameter implants up to 2 years’ follow-up.Materials and methodsThe study was conducted at Kocaeli University Faculty of Dentistry from 2016 to 2018. 37 jaws of 28 patients with an average age of 52 years were rehabilitated with fixed full-arch prostheses supported by 179 implants. Cumulative survival rate (CSR), implant success, marginal bone loss (MBL), and prosthetic survival rate as well as complications were analyzed.ResultsTotal CSR of 99.4% and 98.5% for all and narrow implants respectively have been observed at 2 years’ follow-up. No prosthesis failures were observed, yielding a cumulative prosthetic survival rate of 100%. The NDIs achieved 0.63 mm MBL at 1 year and 1.02 mm at 2 years. The mean MBL at 1 year was 0.51 mm (mandible 0.63 mm/maxilla 0.41 mm) and 0.73 mm (mandible 0.90 mm/maxilla 0.43 mm) at 2 years. Both implant angulation and loading protocol did not influence the MBL.ConclusionsThe combination of narrow-diameter implants with standard-diameter implants in immediate fixed full-arch rehabilitation has a good prognosis to become a new standard of care for severely atrophic jaws.Clinical relevanceThe use of narrow-diameter implants in fixed full-arch rehabilitations in atrophic ridges would be a successful and predictable treatment approach.

Physical characterization of 3 implant systems made of distinct materials with distinct surfaces

Statement of problemDental implants undergo various surface treatments. Studies that have characterized their surface and subsurface by using the same methods are scarce. PurposeThe purpose of this study is to physically characterize the surface and subsurface of implant systems made of commercially pure (cp) titanium (Ti) grade (gr) 4 and Ti alloy gr 23 and to evaluate whether airborne-particle abrasion and acid etching is an appropriate surface treatment for Ti alloy gr 23. Material and methodsImplant groups (n=3) were as follows: TG4AO, cp Ti gr 4, treated with anodic oxidation (3.5×8 mm) (NobelReplace Conical; Nobel Biocare); TG23AE, Ti gr 23 (TiAlV ELI) airborne-particle abraded-and-etched (3.9×8 mm) (V3; MIS); and TG4AE, cp Ti gr 4, airborne-particle abraded and etched (3.3×8 mm) (BL; Institut Straumann AG). Surface roughness, surface topography, and elemental and surface composition were investigated with optical profilometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The presence and size of Ti hydride (TiH) needles were determined on metallographic sections. Depth profiling was obtained by time-of-flight secondary ion mass spectrometry (ToF-SIMS) to determine possible enrichment of an alloying element at the implant surface. ResultsThe mean arithmetic deviation roughness (Sa), of TG4AO was 0.80 μm. The Sa of TG4AO was 1.22 μm, and the Sa of TG4AO was 1.59 μm. The difference between the groups was significant (P<.001). TG23AE and TG4AE displayed a macrotexture and microtexture with pores; TG4AO showed a 3-to 12-μm canyon-like structure. The surface and subsurface compositions were as follows: for TG4AO, αTi and phosphorus-rich anatase; for TG23AE, α-Ti matrix with β-Ti grains; and for TG4AE, α-Ti and δ-TiH2-x. TiH needles were found only on TG4AE; the Ti oxide layer of TG4AO was rough, 3-to 16-μm thick, and porous. The time-of-flight secondary ion mass spectrometry (ToF SIMS) concentration profile of TG23AE did not show enrichment of any alloying element. ConclusionsThe roughness, topography, and composition of the surfaces were different for all implants tested. Airborne-particle abrasion and subsequent etching was an appropriate treatment for Ti gr 23 alloy implants.

Early Loading of Mandibular Molar Single Implants: 1 Year Results of a Randomized Controlled Clinical Trial.

The purpose of this study was to compare the implant survival, peri-implant marginal bone level, and peri-implant soft tissue of three different types of implants. This was performed with an early loading protocol, using a complete digital workflow, for one year of follow-up. Twenty-four patients with a single missing tooth in the mandibular posterior region were randomly assigned to the control group (SLActive Bone level implant; Institut Straumann AG, Basel, Switzerland), experiment group 1 (CMI IS-III Active implant; Neobiotech Co., Seoul, Korea), and experiment group 2 (CMI IS-III HActive implant; Neobiotech Co., Seoul, Korea). For each patient, a single implant was installed using the surgical template, and all prostheses were fabricated using a computer-aided design/computer-aided manufacturing system on a 3-dimensional model. A provisional prosthesis was implanted at 4 weeks, and a definitive monolithic zirconia prosthesis was substituted 12 weeks following the implant placement. The implant stability quotient (ISQ) and peri-implant soft tissue parameters were measured, and periapical radiographs were taken at 1, 3, 4, 8, 12, 24, 36, and 48 weeks after implant placements. Seven implants in the control group, nine implants in the experiment 1 group, and eight implants in the experiment 2 group were analyzed. There were no significant differences among the three groups in terms of insertion torque, ISQ values between surgery and 8 weeks of follow-up, marginal bone loss at 48 weeks of follow-up, and peri-implant soft tissue parameters (P > 0.05). Statistically significant differences in ISQ values were observed between the control and experiment 1 groups, and the control and experiment 2 groups at the 12 to 48 weeks’ follow-ups. Within the limits of this prospective study, an early loading protocol can be applied as a predictable treatment modality in posterior mandibular single missing restorations, achieving proper primary stability.