Narrow Implants Research Articles

The Fatigue Behavior of Narrow Single-body Titanium Implants in Saline and Acidic Media.

The objective of this study was to examine how the saline and acidic environment affects the mechanical integrity of narrow single-body titanium implants for oral rehabilitation. Thirty titanium-base alloy implants with 2.5 mm diameter were placed into a polyacetal holder and coupled to a stainless-steel prosthetic cap for fatigue testing in three different environments, as follows: dry air; saline solution (pH at 7.6); and lactic acid solution (pH at 3.4). The fracture surfaces were analyzed using a Scanning Electron Microscope (SEM). Also, finite element analysis was carried out to estimate the maximum von Mises stresses. The fatigue resistance was higher in the group tested in dry air (60%), followed by saline solution (30%) and lactic acid (10%). Regardless of the environment, fracture occurred at the same region of the failed specimens in line with the highest stress concentration spots, according to the finite element analysis. SEM analyses revealed two distinct failure regions, both with the presence of fatigue streaks: fatigue and overload. A high incidence of secondary cracks was also noticed on the specimens exposed to the solutions. The present study revealed that both saline and acidic solutions significantly affect the fatigue resistance of narrow dental implants. Critical regions of the narrow implants were also susceptible to cracks and plastic deformation that should be taken into consideration in planning for oral rehabilitation.

Can narrow-diameter implants enhance patient-reported outcomes for mandibular implant-retained overdentures?

A systematic review and meta-analysis. To evaluate and compare stability and functionality between narrow and standard implant-retained mandibular overdentures in edentulous patients from multiple perspectives. Assessments included clinical parameters [survival rate (SR) and marginal bone loss (MBL)], along with patient-reported outcome measures (PROMs) including patient satisfaction and oral health-related quality of life (OHRQoL). The study protocol followed PRISMA criteria for reporting reviews and meta-analyses. Using appropriate keywords, electronic search was conducted in each of the following databases: Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus, up to July 22, 2022. There were no restrictions based on language, publication type, or publication date. Additionally, ongoing studies were explored in ClinicalTrials.gov and WHO ICTRP, while cross-references in each selected study were manually examined. The eligible studies were randomized controlled trials (RCTs) or controlled clinical trials (CCTs) comparing narrow implants (diameter ≤ 3.5 mm) to standard implants (diameter > 3.5-4.5 mm) retaining mandibular overdentures in edentulous patients. Excluded were studies with unclear implant diameter information, fewer than 5 patients per group, observational studies, reviews, and laboratory studies. Two authors independently conducted study selection, data collection, and analysis, resolving any discrepancies through discussion with a third author. Methodological quality was assessed using RoB-2 and ROBINS-I tools. Implant SR and MBL measurements at final follow-up were recorded, while patient satisfaction and OHRQoL were evaluated using visual analogue scale (VAS-100) and oral health impact profile (OHIP) questionnaire, respectively. After duplicate removal, 782 publications and 83 registered clinical trials were identified, of which 26 were eligible for full-text assessment. Ultimately, the quantitative evaluation included 12 publications from 8 independent studies: 4 parallel design RCTs and 4 CCTs. Risk of bias assessment revealed variations among the studies, with only one study being rated as having low risk. The follow-up periods ranged from 1 to 3 years. Meta-analysis showed no significant difference in SR and MBL between narrow and standard implant groups (p = 0.29 and p = 0.93, respectively), with considerable heterogeneity (I2 = 100% and I2 = 78%, respectively). Regarding PROMs, the narrow implant group showed significantly higher levels of patient satisfaction (mean difference (MD): 8.18; 95% CI: 5.83 to 10.53; p < 0.00001; I2 = 36%) and exhibited a significant improvement in OHRQoL (MD: -4.36; 95% CI: -6.83 to -1.89; p < 0.001; I2 = 55%) compared to the standard implant group. For implant-retained mandibular overdentures, the use of narrow implants is associated with comparable SR and MBL, along with higher patient satisfaction and better OHRQoL improvement as compared to standard implants, offering a viable alternative option for patients with diminished alveolar bone width.

A One-Year Randomized Controlled Clinical Trial of Three Types of Narrow-Diameter Implants for Fixed Partial Implant-Supported Prosthesis in the Mandibular Incisor Area.

Narrow-diameter implants (NDI) serve as a solution for treating limited bone volume in the anterior mandible. This study aimed to evaluate the one-year clinical outcomes of various NDIs in the mandibular incisor area after immediate loading in partially edentulous patients. This single-center, prospective, single-blinded, randomized controlled trial study included 21 patients, with 7 patients in each of the following groups: control (BLT NC SLActive®; Straumann), experimental group 1 (CMI IS-III Active® S-Narrow; Neobiotech), and experimental group 2 (CMI IS-III Active® Narrow; Neobiotech). Using full digital flow, two fixtures were placed in each patient and immediately provisionalized on the day of surgery. Evaluations encompassed periapical radiographs, implant stability quotient (ISQ), implant stability test (IST) readings, per-implant soft tissue health, patient satisfaction surveys, and esthetic score assessments. Definitive prostheses were delivered twelve weeks post-surgery (CRiS, number: KCT0007300). Following exclusions due to low stability values (n = 2), fixture failure (n = 5), and voluntary withdrawal (n = 1), the implant success rate for patients completing all clinical protocols stood at 100%. The resulting patient failure rates in the control, experimental group 1, and experimental group 2 were 50.0%, 42.9%, and 14.3%, respectively. There were no significant differences between the groups in terms of marginal bone loss, soft tissue health, patient satisfaction, and esthetic scores. Narrow implants showed superior clinical outcomes, followed by S-Narrow and Straumann implants. Calculated one-year survival rates at the implant level were 66.7% for the control group, 85.7% for experimental group 1, and 100% for experimental group 2. All three types of NDIs showed acceptable clinical and radiographic results during the year-long observation period.

Risk factors associated with early implant failure: A retrospective review

PurposeThe purpose of this study was to investigate the association between possible risk factors and early implant failure. Patients and methodsThis retrospective cohort study included consecutive patients receiving dental implant treatment in a four-year timeframe. Patient-related variables (age, sex, smoking, and systemic disease), local factors (area, reason for tooth extraction, and bone quality), surgical variables (bone augmentation, time of implant placement, staging, and antibiotic prophylaxis), and implant-related factors (brand, length, and diameter) were analyzed. Bivariate analyses and multivariate logistic regression model were used to determine the variables associated with early implant failure. ResultsThe study group comprised 1323 implants in 738 patients with a mean of 1.8 implants/patient of which, 53 failed in 52 patients in the early stage (before final prosthetic loading). According to the multivariate model, smoking (Odds Ratio=1.836, P=0.031), posterior maxillary region (OR=2.958, P=0.006), implantation in place of teeth extracted due to periodontal problems (OR=2.531, P=0.004), bone type IV (OR=2.881, P=0.008), implant in previously augmented site (OR=2.239, P=0.014), and immediate provisional prosthesis (OR=3.418, P=0.019) were associated with a significantly higher risk of early implant failure. Narrow implants showed a significantly higher risk of early failure in bivariate analyses (P=0.012). However, the effect was no longer significant in the multivariate model (OR=2.322, P=0.068). ConclusionEarly implant failure would be more expected in smokers, posterior maxilla, history of periodontal problems, type IV bone, augmented bone, and immediately loaded cases.

Narrow Implants and Overdentures in the Total Rehabilitation of Atrophic Edentulous Jaws: Review of Clinical Aspects with Meta-Analysis

Background: The present study analyzes the clinical aspects of the use of small-diameter implants for the fixation of total overdenture-type prostheses on both totally edentulous dental arches. Materials and methods: This is a review of all randomized controlled trials of at least ten patients with a control group in which at least two narrow implants were placed, published between January 2010 and July 2023. Most databases were analyzed, and clinical studies involving the insertion of at least two narrow implants (&lt;3.5 mm in diameter) were analyzed. Results: Studies showed that the survival rate of narrow implants varied from 78% to 100%. Conclusions: The results indicated that narrow-type implants have satisfactory and predictable clinical performance for the long-term stability of overdenture-type prostheses.

Effect of Dynamic Cycles and Abutment Angle on The Screw Stability of Standard and Narrow Implants: An In vitro Study

Objective: Screw loosening in implant-supported crowns is a common issue, leading to potential mechanical and biological complications. This study aimed to evaluate the combined influence of cyclic loading, abutment angulation, and implant diameter on screw torque loss in dental implants. Material and Methods: A total of 80 bone-level implants, divided into standard and narrow diameters, underwent cyclic loading protocols. These implants were paired with straight and 15-degree angled abutments. The study assessed the reverse torque values (RTV) before and after loading, with a primary focus on the effects of cyclic loading, abutment angulation, and implant diameter on screw torque loss. Results: Cyclic loading protocols and screw diameter significantly influenced screw torque loss. Standard diameter implants exhibited higher RTV compared to narrow diameter implants. . While the role of abutment angulation was less definitive, narrow diameter implants with angled placements showed a pronounced decrease in RTV. The study also highlighted that even with optimal preload values, a percentage of the initial preload is lost, potentially leading to screw loosening Conclusion: Cyclic loading and screw diameter are pivotal determinants of screw torque loss in dental implants. The study underscores the need for careful consideration of implant diameter and abutment angulation, especially in narrow diameter implants with angled abutments, to ensure optimal implant stability.

Indications and surgical technique for distraction osteogenesis of the alveolar bone for augmentation prior to insertion of dental implants.

When bone is limited, short, ultra-short, or narrow implants help to restore oral rehabilitation with an acceptable long-term outcome. This becomes more difficult with severe vertical bone loss. Guided bone regeneration, onlay block transplantation, or sandwich osteotomy have been established to build up these defects. The alternative to the alveolar distraction osteogenesis (ADO) has only been established in some centers, with a standardized protocol. On the one hand, ADO is a biological procedure that allows almost a "restitutio ad integrum" when building up hard and soft tissue. On the other hand, there are clear indications, limitations, and complications of the procedure in the literature. In addition to the literature, concept of Tissue Regeneration by Alveolar Callusdistraction Cologne (TRACC), which has been practiced successfully for over two decades, will be presented for different indications.

Reliability and Failure Mode of Ti-Base Abutments Supported by Narrow/Wide Implant Systems.

To assess the reliability and failure modes of Ti-base abutments supported by narrow and wide-diameter implant systems. Narrow (Ø3.5 × 10 mm) and wide (Ø5 × 10 mm) implant systems of two different manufacturers with internal conical connections (16°) and their respective Ti-base abutments (3.5 and 4.5 mm) were evaluated. Ti-base abutments were torqued to the implants, standardized metallic maxillary incisor crowns were cemented, and step stress accelerated life testing of eighteen assemblies per group was performed in three loading profiles: mild, moderate, and aggressive until fracture or suspension. Reliability for missions of 100,000 cycles at 100 and 150 N was calculated, and fractographic analysis was performed. For missions at 100 N for 100,000 cycles, both narrow and wide implant systems exhibited a high probability of survival (≥99%, CI: 94-100%) without significant differences. At 150 N, wide-diameter implants presented higher reliability (≥99%, CI: 99-100%) compared to narrow implants (86%, CI: 61-95%), with no significant differences among manufacturers. Failure mode predominantly involved Ti-base abutment fractures at the abutment platform. Ti-base abutments supported by narrow and wide implant systems presented high reliability for physiologic masticatory forces, whereas for high load-bearing applications, wide-diameter implants presented increased reliability. Failures were confined to abutment fractures.

Implantoplasty and the risk of fracture of narrow implants with advanced bone loss: A laboratory study.

To assess the impact of implantoplasty (IP) on maximum implant failure strength of narrow diameter implants of different type/design and material, with simulated advanced bone loss. Narrow, parallel-walled implants (3.3 mm in diameter × 10 mm long) with an internal connection of different type/design [bone level (BL), tissue level (TL)] and material [Titanium grade IV (Ti), Titanium-Zirconium alloy (TiZr)] from one specific manufacturer were used. Half of the implants were subjected to IP in their coronal 5 mm; the remaining were used as controls (seven implants per group). Dynamic loading prior to maximum load strength testing was included. During dynamic loading, the fracture rate of BL implants was low and independent of IP, while that of TL implants increased significantly with IP compared with controls (p = .001). Maximum implant failure strength reduction (in %) due to IP, was 1.3%-25.4%; TiZr BL implants were least affected. Implants subjected to IP compared to those without IP as well as TL implants compared to BL implants showed a significantly lower maximum implant failure strength (p < .002); implant material was not significant (p = .845). Based on data from implants of one specific manufacturer, IP has a significant negative impact on the fracture strength of narrow implants suffering from advanced peri-implantitis. TL implants have been more severely affected compared to BL implants and presented an increased risk for failure during normal chewing forces. In addition, this negative impact of IP on TL implants was independent of the implant material (i.e., Ti or TiZr). Narrow single TL implants with advanced horizontal bone loss (e.g., 5 mm), when subjected to IP, appear to have an increased fracture risk during normal function.

A Retrospective Clinical Evaluation Of Narrow Diameter Implant Supported Dental Prosthesis: Early Results

Background: Narrow-diameter implants are planned for specific clinical conditions as locator implants between adjacent teeth with a narrow bone width or with only a narrow area in between. They are especially advantageous when restoring narrow teeth like lateral maxillary and mandibular incisors and first premolars.&#x0D; Methods: In the period between 2018 and 2019, 21 patients were rehabilitated with implant treatment. A total of 32 implants were placed (The Straumann® Bone Level Tapered Implants, ∅ 2.9 mm). The survival rates of the implants were analyzed and prosthetic complications were evaluated.&#x0D; Results: The accumulative 36-month survival rate of the implants was 96.9%. Prosthetic complications were mainly limited to loosening occlusal screws. No implant abutment fractures, screw fractures, or porcelain chipping were observed.&#x0D; Conclusion: The results show that narrow implants provide satisfactory treatment outcomes. Narrow implants can be preferred in cases, where the dental operation area is not wide enough.&#x0D; Keywords: Narrow Diameter Implants, Fixed Dental Prosthesis, Survival Rate.

Influence of implant diameter on implant survival rate and clinical outcomes in the posterior area: a systematic review and meta-analysis

ObjectiveThe aim of the present systematic review was to test the hypothesis that the diameter of implants inserted in the posterior area affects implant survival rate, prosthetic survival rate and peri-implant parameters (bleeding on probing (BoP), marginal bone loss (MBL), pocket probing depth (PPD)).Materials and methodsAn electronic search of studies published until December 2021 was done on three databases (Pubmed, Scopus, Cochrane) independently by two authors. Clinical trials comparing implant survival rate, BoP, MBL and PPD among narrow diameter implants (NDI: ≥ 3.0 mm to < 3.75 mm) and regular diameter implants (RDI ≥ 3.75 mm to < 5 mm) were included. Data were independently extracted by two reviewers. Risk of bias was evaluated according to the Cochrane risk-of-bias tool for randomized studies and to the Joanna Briggs Institute Critical Appraisal tools for non-randomized ones. A pair-wise meta-analysis was conducted on the included studies.ResultsSeven articles were included out of the 4291 identified from the digital research. Overall, a total of 939 implants were inserted (319 NDI, 620 RDI). Only one study was judged at serious risk of bias. No statistically significant difference was found in implant survival rate (risk ratio 1.01 (95% CI [0.98 to 1.04], P = 0.67)) while the difference was significant for BoP (mean difference 2.89 (95% CI [0.30 to 5.48] mm, P = 0.03)) with higher values for NDI. Higher MBL was identified among regular diameter implants (mean difference -0.15 mm (95% CI [-0.32 to 0.01 mm], P = 0.07). No statistically significant differences were identified for prosthetic survival and PPD.ConclusionsNo differences were found in implant survival rate between narrow and regular implants. A higher BoP was identified among narrow implants, but there was no higher bone loss. It is not possible to draw definitive conclusions about the use of narrow-diameter implants in the posterior region.

Predictors of Subsidence and Its Clinical Impact Following Expandable Cage Insertion in Minimally Invasive Transforaminal Interbody Fusion.

Retrospective review of prospectively collected multi-surgeon data. Examine the rate, clinical impact, predictors of subsidence after expandable MI-TLIF cage. Expandable cage technology has been adopted in minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) to reduce the risks and optimize outcomes. Although subsidence is of particular concern when using expandable technology as force required to expand the cage can weaken the endplates, its rates, predictors, and outcomes lack evidence. Patients who underwent 1 or 2 level MI-TLIF using expandable cages for degenerative lumbar conditions and had a follow-up of>1 year were included. Preop and immediate, early, and late postoperative radiographs were reviewed. Subsidence was determined if the average anterior/posterior disc height decreased by>25% compared to the immediate postoperative value. Patient reported outcomes were collected and analyzed for differences at the early (<6mo) and late (>6mo) timepoints. Fusion was assessed by 1-year postop CT. 148 patients were included (mean age 61y, 86% 1-level, 14% 2-level). 22 (14.9%) demonstrated subsidence. Although statistically not significant, patients with subsidence were older, lower bone mineral density, and had higher BMI and comorbidity burden. Operative time was significantly higher (P=0.02) and implant width was lower (P<0.01) for subsided patients. VAS-Leg was significantly lower for subsided patients compared to non-subsided patients at a>6m time point. Long-term (>6m) patient acceptable symptom state (PASS) achievement rate was lower for subsided patients (53% vs. 77%), although statistically not significant (P=0.065). No differences existed in complication, reoperation, or fusion rates. 14.9% of patients experienced subsidence predicted by narrower implants. Although subsidence did not have a significant impact on most PROMs and complication, reoperation, or fusion rates, patients had lower VAS-Leg and PASS achievement rate at the>6-month timepoint. 4.

The Effect of Proton Pump Inhibitors on Early Implant Failure A Retrospective Cohort Study

Background and Objectives: Maintenance of a firm and long-term stable osseointegration is the primary goal of implant dentistry. Time is used to define implant failure characteristics. Early implant failure (EIF) occurs up to one year after loading. Recent studies indicated an association between proton pump inhibitors (PPI) therapy and failure of osseointegration. The present study assessed whether the use of PPIs is a risk factor to EIF. Materials and methods: A retrospective cohort study including 687 patients and 2971 dental implants. The study group (PPIs users) comprised 17.3% (119) individuals and 18.7% (555) implants. The remaining cohort (82.7% (568) individuals and 81.3% (2416) implants) served as control. The information was taken from the patients' files. The following information was collected: age, gender, physical status, systemic diseases, HbA1C values before and after implant-supported prosthesis delivery in cases of diabetes mellitus, smoking, implant location, number of implants per individual, bone augmentation, implant brand, length and width, and EIF. EIF was defined as implant removal within a period of up to 12 months from loading. Results: EIF in PPIs vs. non-PPIs users was 19.3% vs. 14.3% (p = 0.16) at patient level and 5.4% vs. 3.5% at implant level (p = 0.03). Univariate analysis yielded factors significantly associated with PPIs use, including older age, physical status of the American Society of Anesthesiology (ASA) 3, hypertension, hyperlipidemia, diabetes mellitus, osteoporosis, cardiovascular accident (CVA), location (anterior mandible), shorter and narrower implants, and higher number of implants per individual. Multivariate analysis yielded statistically significant OR of 1.91; p = 0.01 for EIF following PPIs use and 2.3; p < 0.001 for location in anterior mandible. Conclusions: Patients and their healthcare providers are advised to carefully consider the potential risks of taking PPIs prior to dental implant surgery. Further research is needed to confirm these risks and elucidate systemic and local factors that may be involved in such outcomes.

Planar Elliptical Inductor Design for Wireless Implantable Medical Devices

Wireless implantable medical devices (WIMDs) have seen unprecedented progress in the past three decades. WIMDs help clinicians in better-understanding diseases and enhance medical treatment by allowing for remote data collection and delivering tailored patient care. The wireless connectivity range between the external reader and the implanted device is considered one of the key design parameters in WIMD technology. One of the common modes of communication in battery-free WIMDs is inductive coupling, where the power and data between the reader and the implanted device are transmitted via magnetically coupled inductors. The design and shape of these inductors depend on the requirements of the application. Several studies have reported models of standard planar inductors such as circular, square, hexagonal, and octagonal in medical applications. However, for applications, constrained by narrow implantable locations, elliptical planar inductors may perform better than standard-shaped planar inductors. The aim of this study is to develop a numerical model for elliptical inductors. This model allows for the calculation of the inductance of the elliptical planar inductor and its parasitic components, which are key design parameters for the development of WIMDs powered by inductive coupling. An area transformation technique is used to transform and derive elliptical inductor formulas from standard circular inductor formulas. The proposed model is validated for various combinations of the number of turns, trace width, trace separation, and different inner and outer diameters of the elliptical planar inductor. For a thorough experimental validation of the proposed numerical model, more than 75 elliptical planar inductors were fabricated, measured, and compared with the numerical output of the proposed model. The mean error between the measured inductor parameters and numerical estimates using the proposed model is <5%, with a standard deviation of <3.18%. The proposed model provides an accurate analytical method for estimating and optimizing elliptical planar inductor parameters using a combination of current sheet expression and area transformation techniques. An elliptical planar inductor integrated with a sensing element can be used as a wireless implant to monitor the physiological signal from narrow implantation sites.

Biomechanical Behavior of Narrow Dental Implants Made with Aluminum- and Vanadium-Free Alloys: A Finite Element Analysis.

Titanium (Ti) alloys used for narrow dental implants usually contain aluminum (Al) and vanadium (V) for improved resistance. However, those elements are linked to possible cytotoxic effects. Thus, this study evaluated the biomechanical behavior of narrow dental implants made with Al- and V-free Ti alloys by the finite element method. A virtual model of a partially edentulous maxilla received single implants (diameter: 2.7 and 2.9 mm; length: 10 mm) at the upper lateral incisor area, with respective abutments and porcelain-fused-to-metal crowns. Simulations were performed for each implant diameter and the following eight alloys (and elastic moduli): (1) Ti-6Al-4V (control; 110 GPa), (2) Ti-35Nb-5Sn-6Mo-3Zr (85 GPa), (3) Ti-13Nb-13Zr (77 GPa), (4) Ti-15Zr (113 GPa), (5) Ti-8Fe-5Ta (120 GPa), (6) Ti-26.88Fe-4Ta (175 GPa), (7) TNTZ-2Fe-0.4O (107 GPa), and (8) TNTZ-2Fe-0.7O (109 GPa). The implants received a labially directed total static load of 100 N at a 45° angle relative to their long axis. Parameters for analysis included the maximum and minimum principal stresses for bone, and von Mises equivalent stress for implants and abutments. Ti-26.88Fe-4Ta reaches the lowest maximum (57 MPa) and minimum (125 MPa) principal stress values, whereas Ti-35Nb-5Sn-6Mo-3Zr (183 MPa) and Ti-13Nb-13Zr (191 MPa) models result in the highest principal stresses (the 2.7 mm model surpasses the threshold for bone overload). Implant diameters affect von Mises stresses more than the constituent alloys. It can be concluded that the narrow implants made of the Ti-26.88Fe-4Ta alloy have the most favorable biomechanical behavior, mostly by mitigating stress on peri-implant bone.

Peri-implant bone resorption risk of anterior maxilla narrow single implants: a finite-element analysis

Statement of the problem: Narrow implants have been recommended in high esthetic demand regions to ensure greater buccal bone thickness (BBT) and minimize soft-tissue recession due to insufficient bone support. However, a limited area of bone-implant interface can increase the risk of peri-implant bone resorption due to occlusal forces. Purpose: This article encourages the use of evidence-based finite element analysis to optimize the aesthetic outcomes in maxillary lateral incisor single-supported implant crown by accurate biomechanical planning. This study aimed to analyze the best implant dimensions that would preserve the maximum BBT and avoid peri-implant bone resorption due to occlusal forces. Materials and methods: A maxilla segment was constructed based on anthropological measurements. Four implant diameters (Ø = 3.25; 3.50; 3.75 or 4.00 mm) and two lengths (L = 10 or 13 mm) were simulated. The occlusal force parameters were defined to simulate clinical conditions. The bone resorption risk analysis was based on Frost’s mechanostat theory altering the strain output to strain energy density (SED). The peri-implant bone resorption risk indexes (PIBRri) were calculated by dividing the average of the top ten SED elements of the cortical and trabecular buccal wall by the pathologic resorption limit for each bone. Results: For trabecular bone, only the model Ø4.00L13 exhibited a low PIBRri. For cortical bone, all models presented a low PIBRri, except for models Ø3.25. Conclusion: The selection of a 3.25 mm dental implant to preserve a 2 mm BBT should be avoided since it generates a high peri-implant bone resorption risk induced by occlusal overload.

Influence of diameter on mechanical behavior of morse taper narrow implants

Dental implants could give back function, esthetics and quality of life to patients. The correct choice of the implant, especially in borderline cases, is essential for a satisfactory result. Aim: Thus, the objective of this study was to evaluate the mechanical behavior of Morse taper implants with two different prosthetic interfaces. Methods: Twenty self-locking Morse taper implants, 2.9 mm in diameter (FAC), and 20 Morse taper implants, 3.5 mm in diameter (CM) were divided into two groups (n=10), and submitted to strength to failure test, optical microscopic evaluation of fracture, metallographic analysis of the alloy, finite element analysis (FEA) and strain gauge test. A Student’s t test (α = 0.05) was made for a statistical analysis. Results: For the strength to failure test, a statistically difference was observed (p &lt;0.001) between FAC (225.0 ± 19.8 N) and CM (397.3 ± 12.5 N). The optical microscopic evaluation demonstrated a fracture pattern that corroborated with FEA´s results. The metallographic analysis determined that the implants of the FAC group have titanium-aluminum-vanadium alloy in their composition. In the strain gauge test, there was no statistical difference (p = 0.833) between CM (1064.8 ± 575.04 μS) and FAC (1002.2 ± 657.6 μS) groups. Conclusion: Based on the results obtained in this study, ultra-narrow implants (FAC) should ideally be restricted to areas with low masticatory effort.

Analysis of implant loss risk factors after simultaneous guided bone regeneration: A retrospective study of 5404 dental implants.

The purpose was to analyze the risk factors for implant loss after simultaneous guided bone regeneration (GBR). Patients who underwent implant placement with simultaneous GBR between January 2011 and December 2018 were screened for this study. The cumulative survival rate (CSR) was calculated using the life table method. Log-rank test and Kaplan-Meier survival estimates were used to identify potential risk factors for implant loss. The association between the investigated variables and implant loss was determined using hazard ratios (HRs) obtained from a multivariate Cox regression analysis. A total of 3973 patients with 5404 implants were included in this study. The CSRs of the implants at 1, 5, and 10 years were 99.6%, 98.9%, and 98.7%, respectively. Male patient (HR=2.94, 95% CI: 1.41-6.14), periodontitis (HR=4.26, 95% CI: 2.05-9.86), tissue-level implants (HR=3.02, 95% CI: 1.30-6.98), narrow implants (HR=2.71, 95% CI: 1.12-6.57), and implant length ≤10 mm (HR=2.91, 95% CI: 1.41-6.02) significantly increased the risk of implant loss (p < 0.05). The risk of implant loss was significantly higher in the maxillary posterior region (HR=2.26, 95% CI: 1.04-4.90) than in the maxillary anterior region (p < 0.05). Compared to Straumann, Nobel (HR=4.07, 95% CI: 1.75-9.44) and other implant systems (HR=14.23, 95% CI: 4.32-46.85) showed a significantly higher risk of implant loss (p < 0.05). Male patient, periodontitis, maxillary posterior region, Nobel implant system, other implant systems, tissue-level implants, narrow implants, and implant length ≤10 mm were considered risk factors for implant loss after simultaneous GBR.

The effect of implantoplasty on dental implant fracture resistance: a systematic review

An increase in dental implant placements in recent years has seen a growth in the reported cases of post-operative complications such as peri-implantitis. One of the available treatment modalities to overcome such complications is implantoplasty. Although this procedure is not new, the long-term effect of implantoplasty has not been addressed extensively. The aim of this systematic review was to investigate the change in fracture resistance of dental implants after implantoplasty. Three electronic databases and reference lists of included studies were searched to assess the potential effect of implantoplasty on implant fracture resistance. Titles and abstracts were screened by two reviewers in parallel. The extracted information regarding implant fracture resistance was reported based on the guidelines set by the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. A total of 56 studies were identified, of which, nine studies were included. Narrow platform implants (&lt;3.75 mm) were more susceptible to fracture following implantoplasty compared to wider platforms (?5 mm). Implants with internal hexagon connection may have a higher risk of fracture after implantoplasty compared to other connection designs such as external hexagon and conical connections. Other potential factors which may affect implant fracture resistance after implantoplasty include crown to implant ratio, implant material, and the amount of peri-implant bone loss. Within the limitation of in vitro studies, there is no clear evidence to demonstrate the effect of implantoplasty on implant fracture resistance. Methodological differences between the available studies did not allow for clear comparison between them. Furthermore, the limited amount of clinical reports of this resective procedure, in combination with patient and operator variability, affect the clinical assessment of this treatment modality.

Success of dental implants in patients with large bone defect and analysis of risk factors for implant failure: a non-randomized retrospective cohort study.

This study aimed to retrospectively investigate the success and survival rates of dental implants used for dentomaxillary prostheses at our hospital and the risk factors associated with large bone defects. A total of 138 external joint system implants used for dentomaxillary prostheses in 40 patients with large bone defects were included in this study. The alveolar bone at the site of implant insertion was evaluated using panoramic radiography and computed tomography. Various risk factors (demographic characteristics, dental status, and operative factors such as the employment of alveolar bone augmentation, the site, the length, and diameter of implants) for implant failure and complete implant loss were investigated using univariate and multivariate analyses. The associations between the variables and the success and survival rates of dental implants were analyzed using the multivariate Cox proportional hazard models. The 10-year overall success and survival rates were 81.3% and 88.4% in this study. Multivariable analysis showed that the male sex (HR 6.22), shorter implants (≤ 8.5mm) (HR 5.21), and bone augmentation (HR 2.58) were independent predictors of success rate. Bone augmentation (HR 5.14) and narrow implants (≤ 3.3mm) (HR 3.86) were independent predictors of the survival rate. Male sex, shorter or narrow implants, and bone augmentation were independent risk factors for dental implants used in dentomaxillary prostheses in patients with large bone defects. Clinicians should consider these risk factors and pay close attention to the management of these patients.