Investigating the impact of diameters and thread designs on the Biomechanics of short implants placed in D4 bone: a 3D finite element analysis

Effects of different oral barrier membranes on the efficacy and safety of guided bone regeneration in patients with dental implants: a systematic review and meta-analysis

OBJECTIVE

This study aims to systematically evaluate the effects of different oral barrier membranes on bone regeneration, focusing on their clinical efficacy and safety during dental implant procedures.

METHODS

A comprehensive search was conducted in PubMed, EMBASE, ScienceDirect, Cochrane Library, CNKI, VIP, and CBM databases for case-control and cohort studies published between January 2002 and March 2025. Two independent researchers screened and extracted data, and statistical analysis was performed using RevMan 5.3. The study was registered in PROSPERO (CRD492390).

RESULTS

A total of 11 clinical controlled and cohort studies with 1,003 patients were included. The absorbable membrane group demonstrated a significantly higher success rate (p < 0.05), greater bone graft thickness (p < 0.05), and fewer adverse reactions (p < 0.05). Meta-analysis showed no significant difference in osseointegration, total mineralised tissue, and non-mineralised tissue (p > 0.05).

CONCLUSION

Absorbable oral barrier membranes exhibit superior safety and efficacy profiles, making them a preferred choice for guided bone regeneration. However, further studies with higher methodological quality and longer follow-up durations are required.

Biomechanics of different thread designs of dental implants assisting unilateral free end mandibular partial dentures

BACKGROUND

Dental implants assisting unilateral free end mandibular partial dentures (RPDs) improve their performance and prognosis, however, no consensus exists on the type of thread used in these implants. The current work studied the effect of dental implant thread design on stress distribution around dental implants assisting unilateral free end RPDs using strain gauges and finite element analysis to select the best performing thread design.

METHODS

Twenty-four custom made titanium-aluminum-vanadium (Ti-6Al-4 V) implants were designed and milled 4 thread designs; V-shaped, buttress, reverse-buttress and trapezoid, and were inserted in the approximate locations of tooth number 36 in 6 polymethyl methacrylate Class II Kennedy models, which had teeth number 36, 37, and 38 missing, and unilateral removable partial dentures were constructed to fit each model, with a metal housings and O-rings in their fitting surface attaching to the ball abutment. Surface strains were measured with strain gauges, and mean stresses around the implants, and principal abutments in each tested model were compared using one way analysis of variance (ANOVA). The finite element analysis, recorded stresses, around each dental implant thread design, in the form of colorcoded maps using Von Mises stress analysis.

RESULTS

The recorded micro-strains around V-shaped threads and their related abutments were higher than those recorded around the buttress threads and their related abutments, reverse buttress threads and their related abutments, and trapezoid threads and their related abutments in descending order as determined by one‑way ANOVA (F = 284.489, p < 0.001), and Tukey post hoc pairwise comparison (p < 0.001). FEA results presented the stresses generated around each thread design, under vertical load, the highest stress concentration values were observed around V-shaped threads, followed by the buttress threads, the reverse buttress threads, and finally the least stresses were observed around the trapezoid threads. Under oblique load, more stresses were observed than those under vertical load, being also greatest around V-shaped threads, then decreasing around buttress, reverse buttress, and trapezoid threads.

CONCLUSIONS

The strain gauge and finite element analysis revealed that the trapezoid threads demonstrated least stress concentration at the bone implant interface, followed by the reverse buttress, buttress, and finally the V-shaped threads.

Influence of different implant designs on stress distributions in all-on-four concept: A finite element analysis

The study aims to investigate the effect of different implant designs on stress distribution on the implant and mandibular bone in the All-on-four treatment concept using three-dimensional (3D) finite element analysis (FEA). A 3D FEA model was constructed based on the edentulous mandible's mean value. Eight different implant designs, consisting of two main groups with conical and cylindrical body geometry and four subgroups with four different thread designs, v-shaped, square, buttress, and reversible buttress in each group, were experimentally created in a computer environment. Implants 13 and 15 mm in length were inserted between the mental foraminas according to the All-on-Four concept, and the model was completed with an acrylic hybrid prosthesis created in a computer environment. A total force of 300N was applied with an oblique angle of 75° to the occlusal plane on the premolar and 1st molar teeth. Von Mises stresses (VMS) on the implants, and minimum principal stresses (Pmin) on the cortical and trabecular bones were evaluated using the 3D FEA. VMS and Pmin were lower in the cortical bone around conical, square-thread implants. Stress levels were highest on the cortical bone at the implant neck in all groups, with greater stress observed around posteriorly inclined implants. No direct relationship with trabecular bone was identified. Given the study's limitations, the results suggest using conical squared implants in the All-on-Four concept.

The Influence of Implant Macro-geometry in Primary Stability in Low-Density Bone: An in vitro Study

Aim

This study assessed the primary stability of implants featuring various geometries in polyurethane bone blocks simulating low-density bone types 3 and 4.

Methods

The study included 36 implants divided into three groups (Straumann BLT, n = 12; Zimmer TSV, n = 12; and Dentium Superline [DSL], n = 12). Implants featuring three different thread designs, a tapered body, a diameter of 4.0-4.1 mm, and a length of 10 mm were inserted into polyurethane bone blocks (20 and 15 PCF) to simulate bone types 3 and 4. Primary stability was evaluated using implant stability quotient (ISQ), insertion torque (IT), and removal torque (RT). IT and RT were compared using ANOVA, while ISQ was analyzed using the Kruskal-Wallis test. A P value < 0.05 was considered statistically significant.

Results

For bone type 3, the highest IT (30.21 ± 1.38 N cm) and RT (23.25 ± 2.30 N cm) value were observed for the Zimmer TSV, and the highest ISQ values (63.29 ± 0.54 N cm) were observed for DSL. For bone type 4, the highest IT (18.07 ± 1,71 Ncm) and RT (14.48 ± 1.81 Ncm) values were observed for the Zimmer TSV, and the highest ISQ values (58.46 ± 0.78 N cm) were observed for the DSL. The ISQ, IT, and RT values of the implant groups were significantly different (P < 0.001).

Conclusions

Implant geometry and bone density were key factors influencing primary stability in this study. The outcomes of the present study may help clinicians make decisions, especially when dealing with bone that has a less favorable quality. These findings may have important clinical implications related to immediate or early loading protocols, highlighting the critical role of implant design in attaining sufficient stability.

Microarchitectural Study of the Augmented Bone Following a Modified Ridge Splitting Technique: Histological and Micro-Computed Tomography Analyses

Objectives: The aim of this matched prospective cohort study was to examine the microarchitecture of the augmented bone following a modified alveolar ridge splitting procedure and compare it to that of native bone. Methods: In the test group, patients underwent a modified ridge split osteotomy procedure to restore the width of the posterior segment of the mandible. Patients with sufficient bone width for dental implant placement in the posterior region of the mandible following 3-month-long spontaneous healing after tooth removal were included in the control group. In both study groups, bone biopsy samples were harvested and dental implants were placed. Histomorphometry and micro-CT analysis were performed. Results: Altogether, 15 patients were included in this study (7 patients in the test group, with 14 bone core biopsies harvested, and 8 patients in the control group, with 13 bone core biopsies harvested). Percentage bone volume (BV/TV) in the micro-CT analysis (22.088 ± 8.094% and 12.075 ± 4.009% for the test and control group, respectively) showed statistically significant differences between study groups. Conclusions: Based on histological and micro-CT analyses, the modified ridge splitting procedure with autologous bone block harvested from the retromolar area results in a dental implant recipient bone microarchitecture superior to that of the extraction sockets left to heal undisturbed for a 3-month-long healing period.

Exploring Non-conventional Dental Implants Beyond Traditional Paradigms Part I: Bridging the Gap in Bone Deficiency Cases

Dental implants have revolutionized tooth replacement, offering a functional and aesthetically pleasing alternative to traditional dentures and bridges. While conventional implants, typically titanium screws placed into the jawbone, have become the gold standard, many studies explore non-conventional implant designs and materials to address specific challenges and patient needs. This series of literature reviews aimed to delve into non-conventional dental implants, examining their unique features and applications and the current state of evidence supporting their use. The short and mini dental implants represent a cutting-edge area of research within the field of implant dentistry. Its potential application in the management of cases with limited bone availability has emerged as a viable alternative to the use of bone augmentation procedures. To date, significant progress has been made in the field of dental implants, particularly with the introduction of short and mini dental implants in the management of cases with significant bone deficiency. However, it remains a remarkable challenge that continues to be actively researched.

Jamil F, M. AL-Anee A, Jassim Muhsen S. Relationship Between the Level of Vitamin D3 Deficiency and Successful Osseointegration: A Prospective Clinical Study

Purpose: This study aimed to evaluate the influence of vitamin D3 levels on bone density, primary dental implant stability, and successful osseointegration. Materials and Methods: Clinical and radiological examination with a standardized cone-beam computed tomography (CBCT) machine and laboratory investigation for serum levels of vitamin D3 were performed for all patients. Only patients in need of single or multiple straightforward dental implant surgery in either jaw with no history of systemic disease or condition that may interfere with bone healing were included in this study to receive the dental implant by the same oral and maxillofacial surgeon, which re-opened 4 months later to assess the osseointegration and to complete the prosthetic part. Results: One hundred twenty-eight dental implants were inserted into 108 patients. Most of the patients in the study had insufficient vitamin D3 levels. The prognosis of dental implants regarding successful osseointegration 4 months after implant placement had a weak positive association with the insertion torque and bone mineral density and a statistically significant positive correlation with the serum vitamin D3 level. Conclusion: Preoperatively, it is advisable to request the serum vitamin D3 level of the patients along with the standard clinical and radiological examination. Severe vitamin D3 deficiency could be associated with early dental implant failure despite the favorable bone density and primary dental implant stability achieved. Trial Registration: ClinicalTrials.gov identifier: TCTR20200304001.

Assessment of the Impact of Bone Quality and Abutment Configuration on the Fatigue Performance of Dental Implant Systems Using Finite Element Analysis (FEA)

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate the influence of abutment angulation, types, and bone quality on fatigue performance in dental implant systems.

MATERIALS AND METHODS

Three-dimensional models of maxillary 3-unit fixed implant-supported prostheses were analyzed. Abutments with different angles and types were used. Healthy bone (Hb) and resorbed bone (Rb) were used. Conducted on implants, a force of 150 N was applied obliquely, directed from the palatal to the buccal aspect, at a specific angle of 30 degrees. The stress distribution and fatigue performance were then evaluated considering the types of bone used and the angles of the three different abutments. The simulation aspect of the research was carried out utilizing Abaqus 2020 software.

RESULTS

In all models, fatigue strengths in healthy bone were higher than in resorbed bone. Maximum stress levels were seen in models with angled implants. In almost all models with resorbed bone, fatigue performances were slightly lower.

CONCLUSIONS

Increasing the abutment angle has been shown to increase stress levels and decrease fatigue performance in the adjacent bone and along the implant-abutment interface. In general, implants applied to healthy bone were found to have a higher success rate. It has also been suggested that multiunit abutments have beneficial effects on stress distribution and fatigue performance compared to resin cemented abutments. The type or angle of abutment and the quality of the bone can lead to biomechanical changes that affect the force distribution within the bone structure surrounding the implant. Clinicians can influence the biomechanical environment of the implant site by varying the abutment angle and type to suit the condition of bone health, potentially affecting the long-term success of implant treatment.

Influence of Framework Material and Abutment Configuration on Fatigue Performance in Dental Implant Systems: A Finite Element Analysis

Background and Objectives: This study uses finite element analysis to evaluate the impact of abutment angulation, types, and framework materials on the stress distribution and fatigue performance of dental implant systems. Materials and Methods: Three-dimensional models of maxillary three-unit fixed implant-supported prostheses were analyzed. Abutments with different angles and types were used. Two different framework materials were used. Conducted on implants, a force of 150 N was applied obliquely, directed from the palatal to the buccal aspect, at a specific angle of 30 degrees. The distribution of stress and fatigue performance were then assessed, considering the types of restoration frameworks used and the angles of the abutments in three distinct locations. The simulation aspect of the research was carried out utilizing Abaqus Software (ABAQUS 2020, Dassault Systems Simulation Corp., Johnston, RT, USA). Results: In all models, fatigue strengths in the premolar region were higher than in the molar region. Maximum stress levels were seen in models with angled implants. In almost all models with the zirconia framework, fatigue performance was slightly lower. Conclusions: According to the findings of this study, it was concluded that the use of metal-framework multi-unit restorations with minimum angulation has significant positive effects on the biomechanics and long-term success of implant treatments.

Mechanical and modal analysis of different implant strategies for loss of three teeth with bone atrophy in the maxillary posterior region

PURPOSE

This study aimed to evaluate the stress distribution and secondary stability involved in five implant strategies, including implant-supported prostheses (ISP) and tooth-implant-supported prostheses (TISP), used for bone atrophy in the maxillary posterior region with teeth loss using finite element analysis, and to explore the more desirable implant methods.

METHODS

Five implant strategies were made to analyze and compare: M1, implant-supported prosthesis consisting of a short implant with a regular implant; M2, implant-supported prosthesis consisting of a tilted implant with a regular implant; M3, cantilever structure; M4, tooth-implant-supported prosthesis consisting of a short implant with a regular implant; M5, tooth-implant-supported prosthesis consisting of a regular implant, and M6, with only the natural teeth as a control group. Dynamic loading of the above models was performed in finite element analysis software to assess the stress distribution of the bone tissue and implants using the von Mise criterion. Finally, the secondary stability of different models was evaluated by modal analysis.

RESULTS

The maximum stress distribution in the cortical bone in M1(60 MPa) was smaller than that in M2(97 MPa) and M3(101 MPa), The first principal strain minimum was obtained in M2 (2271μ ε ). M4 (33 MPa, 10085 Hz) with the best mechanical properties and highest resonance frequency. But increased the loading on the natural teeth.

CONCLUSIONS

Short implants and tilted implants are both preferred implant strategies, if cantilever construction is necessary, a tooth-implant-supported prosthesis consisting of a short implant and a regular implant is recommended.

A comprehensive biomechanical evaluation of length and diameter of dental implants using finite element analyses: A systematic review

Background

With a wide range of dental implants currently used in clinical scenarios, evidence is limited on selecting the type of dental implant best suited to endure the biting force of missing teeth. Finite Element Analysis (FEA) is a reliable technology which has been applied in dental implantology to study the distribution of biomechanical stress within the bone and dental implants.

Purpose

This study aimed to perform a systematic review to evaluate the biomechanical properties of dental implants regarding their length and diameter using FEA.

Material and methods

A comprehensive search was performed in PubMed/MEDLINE, Scopus, Embase, and Web of Science for peer-reviewed studies published in English from October 2003 to October 2023. Data were organized based on the following topics: area, bone layers, type of bone, design of implant, implant material, diameter of implant, length of implant, stress units, type of loading, experimental validation, convergence analysis, boundary conditions, parts of Finite Element Model, stability factor, study variables, and main findings. The present study is registered in PROSPERO under number CRD42022382211.

Results

The query yielded 852 results, of which 40 studies met the inclusion criteria and were selected in this study. The diameter and length of the dental implants were found to significantly influence the stress distribution in cortical and cancellous bone, respectively. Implant diameter was identified as a key factor in minimizing peri-implant stress concentrations and avoiding crestal overloading. In terms of stress reduction, implant length becomes increasingly important as bone density decreases.

Conclusions

The diameter of dental implants is more important than implant length in reducing bone stress distribution and improving implant stability under both static and immediate loading conditions. Short implants with a larger diameter were found to generate lower stresses than longer implants with a smaller diameter. Other potential influential design factors including implant system, cantilever length, thread features, and abutment collar height should also be considered in future implant design as they may also have an impact on implant performance.

The current applications of nano and biomaterials in drug delivery of dental implant

BACKGROUND AND AIM

Dental implantology has revolutionized oral rehabilitation, offering a sophisticated solution for restoring missing teeth. Despite advancements, issues like infection, inflammation, and osseointegration persist. Nano and biomaterials, with their unique properties, present promising opportunities for enhancing dental implant therapies by improving drug delivery systems. This review discussed the current applications of nano and biomaterials in drug delivery for dental implants.

METHOD

A literature review examined recent studies and advancements in nano and biomaterials for drug delivery in dental implantology. Various materials, including nanoparticles, biocompatible polymers, and bioactive coatings, were reviewed for their efficacy in controlled drug release, antimicrobial properties, and promotion of osseointegration.

RESULTS

Nano and biomaterials exhibit considerable potential in improving drug delivery for dental implants. Nanostructured drug carriers demonstrate enhanced therapeutic efficacy, sustained release profiles, and improved biocompatibility. Furthermore, bioactive coatings contribute to better osseointegration and reduced risks of infections.

CONCLUSION

Integrating current nano and biomaterials in drug delivery for dental implants holds promise for advancing clinical outcomes. Enhanced drug delivery systems can mitigate complications associated with dental implant procedures, offering improved infection control, reduced inflammation, and optimized osseointegration.

Implant-supported prosthetic rehabilitation after Ameloblastomas treatment: a systematic review

BACKGROUND

Ameloblastoma (AM), the benign counterpart of ameloblastic carcinoma, is a benign odontogenic tumor of epithelial origin, naturally aggressive, with unlimited growth potential and a high tendency to relapse if not adequately removed. Patients with AM treated surgically can benefit from dental implant therapy, promoting oral rehabilitation and improving their quality of life. The present study aimed to determine the survival rate of dental implants placed after surgical treatment of patients affected by AM. In addition, there were two secondary objectives: 1) To evaluate which dental implant loading protocols are most frequently used and 2) To determine the type of prosthetic restoration most commonly used in these patients.

METHODS

The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed during the study. Searches were performed in three databases (PubMed/MEDLINE, Scopus, and Google Scholar) until November 2023. Additionally, the electronic search was enriched by an iterative hand search of journals related to oral pathology and medicine, maxillofacial surgery, and oral prosthodontics and implantology. Only reports and case series in English from January 2003 to date were included. The Joanna Briggs Institute tool (JBI-Case Reports/Case Series) was used for the study quality assessment.

RESULTS

The total number of patients and implants studied were 64 and 271, respectively, all with surgically treated AM. The patient's ages ranged from 8 to 79 years, with a mean (SD) age of 37.3 ± 16.4. Fifty-three percent were male and 47% were female. The range of follow-up duration was 1 to 22 years. An implant survival/success rate of 98.1% was reported. In addition, most of them were conventionally loaded (38.3%). Hybrid implant-supported fixed dentures were the most commonly used by prosthodontists (53%).

CONCLUSIONS

Oral rehabilitation with dental implants inserted in free flaps for orofacial reconstruction in surgically treated patients with AM can be considered a safe and successful treatment modality.

Application of density functional theory for evaluating the mechanical properties and structural stability of dental implant materials

BACKGROUND

Titanium is a commonly used material for dental implants owing to its excellent biocompatibility, strength-to-weight ratio, corrosion resistance, lightweight nature, hypoallergenic properties, and ability to promote tissue adhesion. However, alternative materials, such as titanium alloys (Ti-Al-2 V) and zirconia, are available for dental implant applications. This study discusses the application of Density Functional Theory (DFT) in evaluating dental implant materials' mechanical properties and structural stability, with a specific focus on titanium (Ti) metal. It also discusses the electronic band structures, dynamic stability, and surface properties. Furthermore, it presents the mechanical properties of Ti metal, Ti-Al-2 V alloy, and zirconia, including the stiffness matrices, average properties, and elastic moduli. This research comprehensively studies Ti metal's mechanical properties, structural stability, and surface properties for dental implants.

METHODS

We used computational techniques, such as the CASTEP code based on DFT, GGA within the PBE scheme for evaluating electronic exchange-correlation energy, and the BFGS minimization scheme for geometry optimization. The results provide insights into the structural properties of Ti, Ti-Al-2 V, and zirconia, including their crystal structures, space groups, and atomic positions. Elastic properties, Fermi surface analysis, and phonon studies were conducted to evaluate the tensile strength, yield strength, ductility, elastic modulus, Poisson's ratio, hardness, fatigue resistance, and corrosion resistance.

RESULTS

The findings were compared with those of Ti-Al-2 V and zirconia to assess the advantages and limitations of each material for dental implant applications. This study demonstrates the application of DFT in evaluating dental implant materials, focusing on titanium, and provides valuable insights into their mechanical properties, structural stability, and surface characteristics.

CONCLUSIONS

The findings of this study contribute to the understanding of dental implant material behavior and aid in the design of improved materials with long-term biocompatibility and stability in the oral environment.