Impact of Dental Implant Surface Modifications on Osseointegration

Fibroblasts and osteoblasts behavior after contact with different titanium surfaces used as implant abutment: An in vitro experimental study

Background

The goal of this in vitro study was to compare three different surfaces: two types of implant surfaces commercially available ([a] smooth/machined and [b] acid-treated surface) versus (c) anodized surface. Discs were manufactured with commercially pure titanium (CP) grade IV, which were subsequently analyzed by scanning microscopy and fibroblastic and osteoblastic cell cultures.

Methods

Ninety-nine discs (5 × 2 mm) were manufactured in titanium grade IV and received different surface treatments: (i) Mach group: machined; (ii) AA group: double acid etch; and (iii) AN group: anodizing treatment. Three discs from each group were analyzed by Scanning Electron Microscopy (SEM) to obtain surface topography images and qualitatively analyzed by EDS. Balb/c 3T3 fibroblasts and pre-osteoblastic cells (MC3T3-E1 lineage) were used to investigate each group's biological response (n = 10/cellular type). The data were compared statistically using the ANOVA one-way test, considered as a statistically significant difference p < 0.05.

Results

The AA group had numerous micropores with diameters between 5 and 10 μm, while nanopores between 1 and 5 nm were measured in the AN group. The EDX spectrum showed a high titanium concentration in all the analyzed samples. The contact angle and wetting tension were higher in the AA, whereas similar results were observed for the other groups. A lower result was observed for base width in the AA, which was higher in the other two groups. The AN showed the best values in the fibroblast cells, followed by Mach and AA; whereas, in the culture of the MC3T3 cells, the result was precisely the opposite (AA > Mach > AN). There was similar behavior for cell adhesion for the test groups (Mach and AN), with greater adhesion of Balb/c 3T3 fibroblasts compared to MC3T3 cells; in the AA group, there was greater adherence for MC3T3 cells compared to Balb/c 3T3 fibroblasts.

Conclusions

The findings suggest that different surface characteristics can produce different biological responses, possibly cell-line dependent. These findings have important implications for the design of implantable medical devices, where the surface characteristics can significantly impact its biocompatibility.

Effect of the Sr-Fe layered double hydroxide coating based on the microenvironment response on implant osseointegration in osteoporotic rats

Osteoporosis is a disease that manifests itself as an abnormality of bone metabolism and is characterized by low bone mass and destruction of the bone microstructure. Since bone resorption occurs more rapidly than new bone formation, osteoporosis leads to reduced orthopedic implant stability. From a microenvironmental point of view, the rationale for this outcome is that osteoclasts are overactive in the bone tissue of patients with osteoporosis, and the large amount of H+ they produce leads to local chronic acidosis, which promotes bone mineral loss. Therefore, we designed a weakly alkaline layered double hydroxide (LDH) coating to modulate the pathologically acidic microenvironment and the osteogenic-osteoclastic coupling by releasing Sr2+. We prepared Sr-Fe LDH coatings on pure titanium implants using a hydrothermal method in this study and characterized the material using SEM, AFM, XRD, XPS, EDS, ICP, pH acidimeter, etc. We found that the coatings had good nanomorphology and were able to efficiently neutralize H+ as well as steadily release Sr2+ for up to 21 days. In vitro, the coating not only significantly promoted the adhesion, proliferation, and differentiation of osteoblasts, but also inhibited the differentiation of osteoclasts at the same time. In addition, in animal experiments, the coating significantly improved the mechanical stability of the implant in osteoporotic rats, increasing Sr-Fe LDH@Ti maximal push-out force by 72.2% compared to Ti. At the same time, the coating was effective in reversing the osteoporotic state, resulting in a 58.5% increase in BV/TV (%), and a 12.4% increase in Tb. N (1 mm-1), a 31.6% increase in Tb. Th (μm), and a 30.9% increase in BA (%). Our results suggest that this Sr-Fe LDH nanocoating material with acid-neutralizing, as well as long-term Sr2+-releasing capabilities, is a novel and effective orthopedic implant coating material under osteoporotic conditions.

Evaluation of the accuracy of fully guided implant placement by undergraduate students and postgraduate dentists: a comparative prospective clinical study

PURPOSE

This study aimed to assess the accuracy of implant placement through three-dimensional planning and fully guided insertion, comparing outcomes between undergraduate and postgraduate surgeons.

METHODS

Thirty-eight patients requiring 42 implants in posterior single-tooth gaps were enrolled from the University Clinic for Prosthodontics at the Martin Luther University Halle Wittenberg and the Department of Prosthodontics, Geriatric Dentistry, and Craniomandibular Disorders of Charité University Medicine, Berlin. Twenty-two implants were placed by undergraduate students (n = 18), while 20 implants were placed by trainee postgraduate dentists (n = 5). Pre-operative intraoral scans and cone beam computed tomography images were performed for implant planning and surgical template fabrication. Postoperative intraoral scans were superimposed onto the original scans to analyze implant accuracy in terms of apical, coronal, and angular deviations, as well as vertical discrepancies.

RESULTS

In the student group, two implant insertions were performed by the assistant dentist because of intraoperative complications and, thus, were excluded from further analysis. For the remaining implants, no statistically significant differences were observed between the dentist and student groups in terms of apical (p = 0.245), coronal (p = 0.745), or angular (p = 0.185) implant deviations, as well as vertical discrepancies (p = 0.433).

CONCLUSIONS

This study confirms the viability of fully guided implant placement by undergraduate students, with comparable accuracy to postgraduate dentists. Integration into dental education can prepare students for implant procedures, expanding access and potentially reducing costs in clinical practice. Collaboration is essential for safe implementation, and future research should explore long-term outcomes and patient perspectives, contributing to the advancement of dental education and practice.

TRIAL REGISTRATION

DRKS, DRKS00023024, Registered 8 September 2020-Retrospectively registered, https://drks.de/search/de/trial/DRKS00023024 .

Functionalized biomimetic mineralized collagen promotes osseointegration of 3D-printed titanium alloy microporous interface

Mineralized collagen (MC) is the fundamental unit of natural bone tissue and can induce bone regeneration. Unmodified MC has poor mechanical properties and a single component, making it unable to cope with complex physiological environment. In this study, we introduced sodium alginate (SA) and vascular endothelial growth factor (VEGF) into the MC material to construct functionalized mineralized collagen (FMC) with good mechanical strength and the ability to continuously release growth factors. The FMC is filled into the pores of 3D printed titanium alloy scaffold to form a new organic-inorganic bioactive interface. With the continuous degradation of FMC, bone marrow mesenchymal stem cells (BMSCs) and vascular endothelial cells (VECs) in the surrounding environment are recruited to the surface of the scaffold to promote bone and vascular regeneration. After implanting the scaffold into the distal femoral defect of rabbits, Micro CT, histological, push-out, as well as immunohistochemical analysis showed that the composite interface can significantly promote osseointegration. These findings provide a new strategy for the development and application of mineralized collagen materials.

Comparison of the Photofunctionalization and Platelet-Rich Plasma in the Immediate Implants

Introduction

Many adjuvant methods have been researched to enhance the immediate implant success in the recent times. The study's goal was to compare the aesthetic and biological results of immediate dental implants in the aesthetic zone to standard tapered root form implants that had not undergone pre-treatment with platelet-rich plasma or photofunctionalization.

Materials and Methods

The study used a randomized controlled trial as its design. Ninety subjects were chosen at random and placed into three groups: a control group, a case group, and a group that needed replacement of their maxillary anterior teeth right away following extraction. The interventional groups received the "Platelet-Rich Plasma (PRP)" or "Photofunctionalization (PF)" group before the implant placement. After the delayed loading approach, the prosthesis was given after 6 months. At the second and fourth weeks, as well as 2, 4, 6, and 12 months (P 0.05), follow-up was conducted. The success and survival rate, aesthetic, and biological outcomes were assessed. One-way ANOVA was used to compare outcomes, and repeated-measures ANOVA was used to assess intragroup variations over baseline and follow-up.

Results

The distal, mesial, and mean marginal bone loss as well as the aesthetic scores for pink and white did not differ significantly between groups. The implant stability however was significantly higher in the PF and PRP groups as compared to the controls. A single implant failed in all the three groups. The success percentage was similar for all the groups.

Conclusion

The stability of immediate dental implants pre-treated with PRP or PF differed statistically significantly than the subjects in the control group, while other parameters remained the similar between the groups.

3D printed dental implants with a porous structure: The in vitro response of osteoblasts, fibroblasts, mesenchymal stem cells, and monocytes

AIMS

The first aim of this study was to characterize the surface topography of a novel 3D-printed dental implant at the micro- and macro-level. Its second aim was to evaluate the osteogenic, angiogenic, and immunogenic responses of human oral osteoblasts (hOBs), gingival fibroblasts (hGFs), mesenchymal stem cells (hAD-MSCs), and monocytes to this novel implant surface.

METHODS

A 3D-printed Ti-6Al-4 V implant was produced by selective laser melting and subjected to organic acid etching (TEST). It was then compared to a machined surface (CTRL). Its biological properties were evaluated via cell proliferation assays, morphological observations, gene expression analyses, mineralization assessments, and collagen quantifications.

RESULTS

Scanning electron microscopy analysis showed that the TEST group was characterized by a highly interconnected porous architecture and a roughed surface. The morphological observations showed good adhesion of cells cultured on the TEST surface, with a significant increase in hOB growth. Similarly, the gene expression analysis showed significantly higher levels of osseointegration biomarkers. Picrosirius staining showed a slight increase in collagen production in the TEST group compared to the CTRL group. hAD-MSCs showed an increase in endothelial and osteogenic commitment-related markers. Monocytes showed increased mRNA synthesis related to the M2 (anti-inflammatory) macrophagic phenotype.

CONCLUSIONS

Considering the higher interaction with hOBs, hGFs, hAD-MSCs, and monocytes, the prepared 3D-printed implant could be used for future clinical applications.

CLINICAL RELEVANCE

This study demonstrated the excellent biological response of various cells to the porous surface of the novel 3D-printed implant.

Comparison of Roughness, Wettability, and SEM Features between Sandblasted Acid-Etched and Oxidized Titanium Dental Implants

The surface of dental implants has undergone multiple modifications across the timeline to enhance osseointegration, thereby enhancing the success of dental implants. This study compared the surface roughness, wettability and topography of sandblasted acid-etched, and oxidized titanium dental implants. Three commercially available implants-namely, SLA, SLActive, and TiUnite-were evaluated for surface roughness in terms of Ra, Rq, and Rz; wettability in terms of contact angle (CA); and topography using scanning electron microscopy (SEM). Roughness and wettability values were compared between the three surfaces by ANOVA and pairwise comparison by Tukey's HSD post hoc testing using SPSS Software. A p value of < 0.01 was considered to be statistically significant. The TiUnite surface exhibited the highest roughness values (Ra = 1.91 ± 0.006 μm, Rq = 2.99 ± 0.005 μm, Rz = 8.37 ± 0.003 μm) followed by the SLA and SLActive surfaces. The contact angles of the SLA, SLActive, and TiUnite dental implants were 98.44 ± 0.52°, 9 ± 0.03°, and 94.39 ± 0.08°, respectively. These data demonstrated statistically significant differences between the three surfaces (p < 0.01). There were no distinct differences in SEM features between the SLA and SLActive surfaces. However, the TiUnite surface exhibited a distinctly porous morphology. Oxidized dental implants differ from sandblasted acid-etched implants in terms of roughness, wettability, and surface topography.

Comparison of Malondialdehyde Levels among Patients with Sandblasted Acid-Etched and Anodized Surface Dental Implants: A Prospective Clinical Study

Inflammation that occur as a part of body's response to implant-tissue contact can result in oxidative stress. Therefore, exploring the oxidative stress around different surface treated dental implants is essential to improve the performance of implants. The purpose of this study was to detect and measure the level of malondialdehyde (MDA), oxidative stress marker among patients with sandblasted acid-etched and anodized surface dental implants. In this prospective clinical study, 78 patients who had undergone implant placement for missing single posterior tooth in mandible using sandblasted acid-etched and anodized surface dental implants during August 2019 - December 2019 were enrolled according to strict inclusion and exclusion criteria and were categorized into Group 1: SLA (n = 27), Group 2: SLActive (n = 26), Group 3: TiUnite (n = 25) based on the surface modification of the implants. Peri-implant crevicular fluid (PICF) was collected and MDA was quantified using ELISA kit at 3 months and 1 year. Statistical analysis was performed using one-way ANOVA, followed by Tukey's HSD post hoc. For intragroup comparison, paired t-test was used. MDA levels in group 3 implants was significantly higher than groups 1 and 2 (P ≤ 0.05). On pairwise comparison, there was a statistically significant difference between the groups at baseline (P ≤ 0.05) and 1-year follow-up (P ≤ 0.05). Intragroup comparison showed that there was a statistically significant difference from baseline in all the three groups (P ≤ 0.05). MDA level in peri-implant crevicular fluid was high around TiUnite dental implant as compared to SLA and SLActive implants.

Antibiotic prophylaxis dysregulates dental implant placement surgery-induced osteoimmune wound healing and attenuates the alveolar bone-implant interface in mice

AIM

Antimicrobial-induced shifts in commensal oral microbiota can dysregulate helper T-cell oral immunity to affect osteoclast-osteoblast actions in alveolar bone. Antibiotic prophylaxis is commonly performed with dental implant placement surgery to prevent post-surgical complications. However, antibiotic prophylaxis effects on osteoimmune processes supporting dental implant osseointegration are unknown. The aim of the study was to discern the impact of antibiotic prophylaxis on dental implant placement surgery-induced osteoimmune wound healing and osseointegration.

MATERIALS AND METHODS

We performed SHAM or dental implant placement surgery in mice. Groups were administered prophylactic antibiotics (amoxicillin or clindamycin) or vehicle. Gingival bacteriome was assessed via 16S sequencing. Helper T-cell oral immunity was evaluated by flow cytometry. Osteoclasts and osteoblasts were assessed via histomorphometry. Implant osseointegration was evaluated by micro-computed tomography.

RESULTS

Dental implant placement surgery up-regulated TH 1, TH 2 and TREG cells in cervical lymph nodes (CLNs), which infers helper T-cell oral immunity contributes to dental implant placement osseous wound healing. Prophylactic antibiotics with dental implant placement surgery caused a bacterial dysbiosis, suppressed TH 1, TH 2 and TREG cells in CLNs, reduced osteoclasts and osteoblasts lining peri-implant alveolar bone, and attenuated the alveolar bone-implant interface.

CONCLUSIONS

Antibiotic prophylaxis dysregulates dental implant placement surgery-induced osteoimmune wound healing and attenuates the alveolar bone-implant interface in mice.

Investigating the effect of insertion torque on marginal bone loss around dental implants

BACKGROUND/PURPOSE

The use of dental implants in restoring function, esthetics, speech, and health of oral tissues has been growing in recent years. Evaluating marginal bone resorption and the survival rate of implants placed with different torques values is crucial. The primary aim of the present study was to evaluate the effect of different insertion torque values on marginal bone loss around dental implants placed in the posterior region of the mandible.

MATERIALS AND METHODS

37 patients were involved in this study. Patient data (age, gender), implant characteristics (length, diameter), insertion torque values, gingival biotype, and bone quality were recorded, and parallel periapical radiographs measured marginal bone loss. The relationship between variables was obtained using independent t-tests, Pearson correlations, and regressions.

RESULTS

The present study found a positive and significant correlation between implant insertion torque and marginal bone loss (MBL)around the dental implants during the first year after placement. Furthermore, patients with D2 bone density at the implant placement site and thin gingival biotype also had significantly higher MBLs from baseline until crown delivery and first-year follow-up than those with D3 bone density and thick gingival biotypes, respectively.

CONCLUSION

A lower torque is necessary for high-risk patients to increase implantation success due to identifying patients with an increased risk for MBL.

Influence of Topography and Composition of Commercial Titanium Dental Implants on Cell Adhesion of Human Gingiva-Derived Mesenchymal Stem Cells: An In Vitro Study

The topography and composition of dental implant surfaces directly impact mesenchymal cell adhesion, proliferation, and differentiation, crucial aspects of achieving osseointegration. However, cell adhesion to biomaterials is considered a key step that drives cell proliferation and differentiation. The aim of this study was to characterize characterize the topography and composition of commercial titanium dental implants manufactured with different surface treatments (two sandblasted/acid-etched (SLA) (INNO Implants, Busan, Republic of Korea; BioHorizonsTM, Oceanside, CA, USA) and two calcium phosphate (CaP) treated (Biounite®, Berazategui, Argentina; Zimmer Biomet, Inc., Warsaw, IN, USA)) and to investigate their influence on the process of cell adhesion in vitro. A smooth surface implant (Zimmer Biomet, Inc.) was used as a control. For that, high-resolution methodologies such as scanning electron microscopy (SEM), X-ray dispersive spectroscopy (EDX), laser scanning confocal microscopy (LSCM), and atomic force microscopy (AFM) were employed. Protein adsorption and retromolar gingival mesenchymal stem cells (GMSCs) adhesion to the implant surfaces were evaluated after 48 h. The adherent cells were examined by SEM and LSCM for morphologic and quantitative analyses. ANOVA and Tukey tests (α = 0.05) were employed to determine statistical significance. SEM revealed that INNO, BioHorizonsTM, and Zimmer implants have an irregular surface, whereas Biounite® has a regular topography consisting of an ordered pattern. EDX confirmed a calcium and phosphate layer on the Biounite® and Zimmer surfaces, and AFM exhibited different roughness parameters. Protein adsorption and cell adhesion were detected on all the implant surfaces studied. However, the Biounite® implant with CaP and regular topography showed the highest protein adsorption capacity and density of adherent GMSCs. Although the Zimmer implant also had a CaP treatment, protein and cell adhesion levels were lower than those observed with Biounite®. Our findings indicated that the surface regularity of the implants is a more determinant factor in the cell adhesion process than the CaP treatment. A regular, nanostructured, hydrophilic, and moderately rough topography generates a higher protein adsorption capacity and thus promotes more efficient cell adhesion.

Construction of functional surfaces for dental implants to enhance osseointegration

Dental implants have been extensively used in patients with defects or loss of dentition. However, the loss or failure of dental implants is still a critical problem in clinic. Therefore, many methods have been designed to enhance the osseointegration between the implants and native bone. Herein, the challenge and healing process of dental implant operation will be briefly introduced. Then, various surface modification methods and emerging biomaterials used to tune the properties of dental implants will be summarized comprehensively.

Significance of bone morphology and quality on the primary stability of orthodontic mini-implants: in vitro comparison between human bone substitute and artificial bone

AIM

This study evaluated artificial bone models against a human bone substitute to assess the primary stability of orthodontic mini-implants (OMIs) at varying implant sites with different morphologies and qualities.

MATERIALS AND METHODS

A total of 1200 OMI placements of four types were inserted into four artificial bone models of different density (D1, D2, D3, D4) and into a human bone substitute (HB). The implants varied in diameter (2.0 and 2.3 mm) and length (9 and 11 mm). Each specimen had four implant sites: no defect, one-wall defect, three-wall defect, and circular defect. The implant stability quotient (ISQ) values were measured using resonance frequency analysis (RFA) and insertion placement torque values (IPT) were assessed for primary stability. Correlation analysis was performed to evaluate the different models.

RESULTS

The highest IPT value was registered for the 2.0 mm × 11 mm implant inserted into D1 with no defect (37.53 ± 3.02 Ncm). The lowest ISQ value was measured for the 2.3 mm × 9 mm OMI inserted into D3 with a circular defect (12.33 ± 5.88) and the highest for the 2.3 mm × 9 mm implant inserted into HB with no defect (63.23 ± 2.57). A strong correlation (r = 0.64) for IPT values and a very strong correlation (r = 0.8) for ISQ values was found between D2 and HB.

CONCLUSION

Bone defects and bone quality affected the primary stability of implants in terms of ISQ and IPT values. Results for bone model D2 correlated very well with the HB substitution material.

Optimizing Osseointegration in Dental Implantology: A Cross-Disciplinary Review of Current and Emerging Strategies

The paper explores the correlation between osteointegration and dental implant stability, investigating the relationship and its implications for successful outcomes in implant dentistry. Osteointegration, defined as the direct structural and functional connection between living bone and the implant surface, plays a crucial role in determining the stability and long-term success of dental implants. This review synthesizes current knowledge from scientific literature and clinical studies to elucidate the factors influencing osteointegration and their impact on implant stability. Surface characteristics of implants, such as topography and chemistry, as well as the surgical techniques employed during implant placement, are examined in detail, emphasizing their significant influence on osseointegration and subsequent implant stability. Additionally, host-related factors such as bone quality, systemic conditions, and patient-specific considerations are explored to further comprehend the complexity of the osteointegration process. The abstract underscores the importance of achieving an optimal bone-implant interface to ensure successful implant integration and stability. Furthermore, emerging technologies and materials, such as computer-guided implant placement and biomimetic surfaces, are discussed for their potential to enhance osteointegration and improve long-term implants.

Bone density and proximal support effects on dental implant stability - Finite element analysis and in vitro experiments

OBJECTIVES

The application of dental implants presents the occurrence of implant failures associated with bone proximal support. This study aims to assess implant behavior, in particular implant stability and strain distribution in the bone at different bone densities, and the effect of proximal bone support.

MATERIAL AND METHODS

Three bone densities (D20, D15, and D10) were considered in the experimental in vitro study, represented by solid rigid polyurethane foam and two conditions of bone support in the proximal region. A finite element model was developed and validated experimentally and a Branemark model at a 3:1 scale was implanted in the experiments; the model was loaded and extracted.

RESULTS

The results of the experimental models validate the finite element models with a correlation R2 equal to 0.899 and NMSE of 7%. The implant extraction tests for the effect of bone properties in the maximum load were 2832 N for D20 and 792 N for D10. The effect of proximal bone support changes the implant stability was observed experimentally; at 1 mm less bone support decreases by 20% of stability and at 2 mm by 58% for D15 density.

CONCLUSIONS

Bone properties and bone quantity are important for the initial stability of the implant. A bone volume fraction of less than 24 g/cm3 exhibits poor behavior and is not indicated for implantation. Proximal bone support reduces the primary stability of the implant and the effect is critical in lower bone density.

Comparison of marginal bone loss in SLA and RBM implants: A prospective cohort study

Context

The study aims to answer the following question: Among the patients who received a dental implant, is there any difference in marginal bone loss (MBL) between sandblasted and acid-etched (SLA) and resorbable blast media (RBM) implants?

Aims

The study aimed to evaluate marginal bone loss in SLA and RBM implants one year after loading.

Settings and Design

A Prospective Cohort Study.

Methods and Material

In this prospective cohort study with a pre-protocol population, subjects were assigned into two groups: Subjects received SLA implants in group 1 and RBM in group 2. MBL was assessed 12 months after loadings through digital parallel radiographs.

Statistical Analysis Used

An Independent t-test was used to compare MBL between the two groups.

Results

Sixty-six implants were studied (each group 33 implants). The mean of MBL in the RBM group was significantly higher than the SLA group (1.39 ± 0.31 mm, 0.89 ± 0.26 mm, respectively, P < 0.001). MBL in the mesial sides of implants in the RBM group was significantly higher than the SLA group (1.28 ± 0.29 mm, 0.8 ± 0.29 mm, respectively, P < 0.001). Analysis of the data demonstrated a significantly higher mean of MBL in the distal sides of implants in the RBM group than in the SLA group (1.51 ± 0.35 mm, 0.97 ± 0.27 mm, respectively, P < 0.001). In both groups, the mean of MBL on the distal side was significantly higher than on the mesial side (P < 0.05).

Conclusions

Within this study's limitation, RBM implants showed significantly more MBL than SLA implants.

Application of virtual reality in dental implants: a systematic review

BACKGROUND AND OBJECTIVE

A treatment approach that is widely used as a permanent and natural replacement for missing or extracted teeth is dental implants .VR is a computer-generated simulation that creates a three-dimensional (3D) image or environment. Advances in VR -based learning allow learners and students to practice and also help professionals plan a wide variety of surgical procedures, including the correct placement of dental implants. Therefore, in this systematic review, our aim was to investigate and evaluate the available virtual reality tools for dental implants and their effectiveness.

MATERIALS AND METHODS

Studies published up to 01/30/2023 which report the applications of using virtual reality technology in dental implants, were reviewed in three databases, including PubMed, Web of Science, and Scopus. All studies with evidence reporting the role of virtual reality technology in the field of dental implants were included in our analyses, written in English and published in peer-reviewed form, are included. Theoretical articles, and letters that did not provide original data, as well as studies that reported incomplete information, were excluded. Two reviewers independently assessed search results, extracted data, and assessed the quality of the included studies, and decisive agreement was reached by discussion and consultation with the third researcher. Narrative synthesis was undertaken to summarize and report the findings.

RESULTS

Out of 1633 initial search results, nine were included in the present study based on the inclusion criteria. The focus of seven studies was on teaching and learning, and two studies have examined the implant planning procedure. The most commonly used hardware and software were head-mounted display and Unity3D, respectively. In almost all studies, the results showed that the use of virtual reality-based systems improves and enhances the skills of users, including dental students and specialists.

CONCLUSIONS

Our findings showed that VR is an effective method for teaching and planning the implant process. Although the use of VR technology is limited for various reasons such as cost, it can increase the skills of dental professionals in performing dental implants.

A Nonlinear Three-Dimensional Finite Element Analysis of Stress Distribution and Microstrain Evaluation in Short Dental Implants with Three Different Implant-Abutment Connections in Single and Splinted Conditions in the Posterior Mandible

Background

Stress distribution plays a vital role in the longevity and success of implant-supported prosthesis. This study evaluated the von Mises stress and microstrain in the peri-implant bone and the implant-abutment junction of short dental implants with three different implant-abutment connections in splinted and unsplinted conditions using finite element analysis (FEA).

Materials and Methods

In this experimental study, nine transversely isotropic finite element models were developed, and randomly divided into three equal groups (n = 3): control, (Group AC) single-standard 4.3 × 10 mm bone level implant-supported restorations with external hexagonal (EH) connection, internal conical (IC) and internal trichannel (ITC) connection, single short implant-supported restorations (Group AT), and splinted short implant-supported restorations (Group B) for each of the three implant-abutment connections, respectively. A 200 N load was applied along the long axis of the implants and a 100 N (45°) oblique load was applied and von Mises stress and microstrain values were evaluated.

Results

Single standard implants demonstrated the highest von Mises stress and microstrain values followed by single short implants and splinted short implants, respectively. Among the implant-abutment connections, the IC connection showed the highest values and the ITC connection showed the least values.

Conclusion

Within the limitations of this study, it was concluded that splinting of short dental implants demonstrated lesser and more homogeneous stress and microstrain, especially on oblique loading. The microstrain values for all connections evaluated were within the physiological loading limit (200-2,500 N) and were hence considered safe for clinical use.

Engineering Antioxidant Surfaces for Titanium-Based Metallic Biomaterials

Prolonged inflammation induced by orthopedic metallic implants can critically affect the success rates, which can even lead to aseptic loosening and consequent implant failure. In the case of adverse clinical conditions involving osteoporosis, orthopedic trauma and implant corrosion-wear in peri-implant region, the reactive oxygen species (ROS) activity is enhanced which leads to increased oxidative stress. Metallic implant materials (such as titanium and its alloys) can induce increased amount of ROS, thereby critically influencing the healing process. This will consequently affect the bone remodeling process and increase healing time. The current review explores the ROS generation aspects associated with Ti-based metallic biomaterials and the various surface modification strategies developed specifically to improve antioxidant aspects of Ti surfaces. The initial part of this review explores the ROS generation associated with Ti implant materials and the associated ROS metabolism resulting in the formation of superoxide anion, hydroxyl radical and hydrogen peroxide radicals. This is followed by a comprehensive overview of various organic and inorganic coatings/materials for effective antioxidant surfaces and outlook in this research direction. Overall, this review highlights the critical need to consider the aspects of ROS generation as well as oxidative stress while designing an implant material and its effective surface engineering.

Investigation of the Influence of Roughness and Dental Implant Design on Primary Stability via Analysis of Insertion Torque and Implant Stability Quotient: An In Vitro Study

In the placement of dental implants, the primary fixation between the dental implant and the bone is of great importance and corresponds to compressive mechanical fixation that aims to prevent micromovement of the implant. The aim of this research was to determine the role of roughness and the type of dental implant (tissue-level or bone-level) in implant stability, measured using resonance frequency analysis (RFA) and insertion torque (IT). We analyzed 234 titanium dental implants, placed in fresh calf ribs, at the half-tissue level and half-bone level. The implant surface was subjected to grit-blasting treatments with alumina particles of 120, 300, and 600 μm at a projection pressure of 2.5 bar, resulting in three types of roughness. Roughness was determined via optical interferometry. The wettability of the surfaces was also determined. Implant stability was measured using a high-precision torquemeter to obtain IT, and RFA was used to determine the implant stability quotient (ISQ). The results show that rough surfaces with Sa values of 0.5 to 4 μm do not affect the primary stability. However, the type of implant is important; bone-level implants obtained the highest primary stability values. A good correlation between the primary stability values obtained via IT and ISQ was demonstrated. New in vivo studies are necessary to know whether these results can be maintained in the long term.

Optimized Gingiva Cell Behavior on Dental Zirconia as a Result of Atmospheric Argon Plasma Activation

Several physico-chemical modifications have been developed to improve cell contact with prosthetic oral implant surfaces. The activation with non-thermal plasmas was one option. Previous studies found that gingiva fibroblasts on laser-microstructured ceramics were hindered in their migration into cavities. However, after argon (Ar) plasma activation, the cells concentrated in and around the niches. The change in surface properties of zirconia and, subsequently, the effect on cell behavior is unclear. In this study, polished zirconia discs were activated by atmospheric pressure Ar plasma using the kINPen^®09 jet for 1 min. Surfaces were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and water contact angle. In vitro studies with human gingival fibroblasts (HGF-1) focused on spreading, actin cytoskeleton organization, and calcium ion signaling within 24 h. After Ar plasma activation, surfaces were more hydrophilic. XPS revealed decreased carbon and increased oxygen, zirconia, and yttrium content after Ar plasma. The Ar plasma activation boosted the spreading (2 h), and HGF-1 cells formed strong actin filaments with pronounced lamellipodia. Interestingly, the cells' calcium ion signaling was also promoted. Therefore, argon plasma activation of zirconia seems to be a valuable tool to bioactivate the surface for optimal surface occupation by cells and active cell signaling.

Laser microgrooving and resorbable blast texturing for enhanced surface function of titanium alloy for dental implant applications

Long-term dental implant success is dependent on biocompatibility and osseointegration between the bone and the implant. Surface modifications such as laser-induced microgrooving which increase contact area can enhance osseointegration by establishing and directing a stable attachment between the implant surface and peri-implant bone. The objective of this study was to evaluate pre-osteoblast proliferation, morphology, and differentiation on titanium alloy (Ti64) surfaces-Laser-Lok^© (LL), resorbable blast textured (RBT), and machined (M)-compared to tissue culture plastic (TCP) control. We hypothesized the LL surfaces would facilitate increased cellular alignment compared to all other groups, and LL and RBT surfaces would demonstrate enhanced proliferation and differentiation compared to M and TCP surfaces. Surface roughness was quantified using a surface profilometer, and water contact angle was measured to evaluate the hydrophilicity of the surfaces. Cellular function was assessed using quantitative viability and differentiation assays and image analyses, along with qualitative fluorescent (viability and cytoskeletal) imaging and scanning electron microscopy. No differences in surface roughness were observed between groups. Water contact angle indicated LL was the least hydrophilic surface, with RBT and M surfaces exhibiting greater hydrophilicity. Cell proliferation on day 2 was enhanced on both LL and RBT surfaces compared to M, and all three groups had higher cell numbers on day 2 compared to day 1. Cell orientation was driven by the geometry of the surface modification, as cells were more highly aligned on LL surfaces compared to TCP (on day 2) and RBT (on day 3). At day 21, cell proliferation was greater on LL, RBT, and TCP surfaces compared to M, though no differences in osteogenic differentiation were observed. Collectively, our results highlight the efficacy of laser microgrooved and resorbable blast textured surface modifications of Ti64 for enhancing cellular functions, which may facilitate improved osseointegration of dental implants.

Comparison of Osseointegration in Novel Laser-Textured and SLA Implants

Background

Osseointegration is defined as the direct structural and functional connection between neo-formed bone and dental implants. Among the parameters suggested to predominantly influencing the establishment of a successful osseointegration is the quality of the implant surface, which may enhance the strength and speed of this biomechanical process.

Objective

The purpose of this study was to evaluate the ability of a novel laser-treated surface, compared to sandblasted, large-grit, acid-etched (SLA) surfaces, to enhance and accelerate implant integration in delayed implant placement.Methods: Thirty patients with two missing posterior teeth were enrolled in this study. Each patient received, at a randomly allocated site, an implant with a conventional SLA surface, and at a second site, an implant with laser-textured surface. A total of 60 tissue-level implants were subsequently placed. Implant stability (ISQ) was measured using resonance frequency analysis (RFA). ISQ was assessed at baseline (T0), 8 weeks (T1), and 12 weeks (T2) following implant placement. Results: There was a statistical difference in implant stability between laser-textured and SLA group at 12 weeks postoperatively. Implant stabilization showed a successful osseointegration with both surface types.

Conclusion

Both laser and SLA surface treatments had positive impacts on implant stabilization following delayed placement. Laser-treated surfaces presented higher values of osseointegration at 3 months postoperatively.

Surface Coatings of Dental Implants: A Review

Replacement of missing teeth is possible using biocompatible devices such as endosseous implants. This study aims to analyze and recognize the best characteristics of different implant surfaces that ensure good peri-implant tissue healing and thus clinical success over time. The present review was performed on the recent literature concerning endosseous implants made of titanium, a material most frequently used because of its mechanical, physical, and chemical characteristics. Thanks to its low bioactivity, titanium exhibits slow osseointegration. Implant surfaces are treated so that cells do not reject the surface as a foreign material and accept it as fully biocompatible. Analysis of different types of implant surface coatings was performed in order to identify ideal surfaces that improve osseointegration, epithelial attachment to the implant site, and overall peri-implant health. This study shows that the implant surface, with different adhesion, proliferation, and spreading capabilities of osteoblastic and epithelial cells, influences the cells involved in anchorage. Implant surfaces must have antibacterial capabilities to prevent peri-implant disease. Research still needs to improve implant material to minimize clinical failure.

Effects of Cold Atmospheric Plasma Pre-Treatment of Titanium on the Biological Activity of Primary Human Gingival Fibroblasts

Cold atmospheric plasma treatment (CAP) enables the contactless modification of titanium. This study aimed to investigate the attachment of primary human gingival fibroblasts on titanium. Machined and microstructured titanium discs were exposed to cold atmospheric plasma, followed by the application of primary human gingival fibroblasts onto the disc. The fibroblast cultures were analyzed by fluorescence, scanning electron microscopy and cell-biological tests. The treated titanium displayed a more homogeneous and denser fibroblast coverage, while its biological behavior was not altered. This study demonstrated for the first time the beneficial effect of CAP treatment on the initial attachment of primary human gingival fibroblasts on titanium. The results support the application of CAP in the context of pre-implantation conditioning, as well as of peri-implant disease treatment.

Photobiomodulation-Based Synergic Effects of Pt-Coated TiO2 Nanotubes and 850 nm Near-Infrared Irradiation on the Osseointegration Enhancement: In Vitro and In Vivo Evaluation

Photobiomodulation (PBM) therapy is known to have the potential to improve bone regeneration after implant surgery. However, the combinatory effect of the nanotextured implant and PBM therapy on osseointegration has not yet been proved. This study evaluated the photobiomodulation-based synergistic effects of Pt-coated titania nanotubes (Pt-TiO₂ NT) and 850 nm near-infrared (NIR) light on osteogenic performance in vitro and in vivo. The FE-SEM and the diffuse UV-Vis-NIR spectrophotometer were used to perform the surface characterization. The live-dead, MTT, ALP, and AR assays were tested to perform in vitro tests. The removal torque testing, the 3D-micro CT, and the histological analysis were used to conduct in vivo tests. The live-dead and MTT assay resulted in Pt-TiO₂ NTs being biocompatible. The ALP activity and AR assays demonstrated that the combination of Pt-TiO₂ NT and NIR irradiation significantly enhanced osteogenic functionality (p < 0.05). The results of in vivo test, employing the removal torque testing, the 3D-micro CT, and histological analysis, showed overall improved outcomes; however, no significant difference was observed between the control and experimental groups (p > 0.05). Therefore, we confirmed the possibility of the combination of Pt-TiO₂ NT and NIR light as a promising technology for implant surgery in dentistry.

Influence of Surface Characteristics of TiO2 Coatings on the Response of Gingival Cells: A Systematic Review of In Vitro Studies

The soft tissue-implant interface requires the formation of epithelium and connective tissue seal to hinder microbial infiltration and prevent epithelial down growth. Nanoporous titanium dioxide (TiO₂) surface coatings have shown good potential for promoting soft tissue attachment to implant surfaces. However, the impact of their surface properties on the biological response of gingival cells needs further investigation. This systematic review aimed to investigate the cellular behavior of gingival cells on TiO₂-implant abutment coatings based on in vitro studies. The review was performed to answer the question: "How does the surface characteristic of TiO₂ coatings influence the gingival cell response in in vitro studies?". A search in MEDLINE/PubMed and the web of science databases from 1990 to 2022 was performed using keywords. A quality assessment of the studies selected was performed using the SciRAP method. A total of 11 publications were selected from the 289 studies that fulfilled the inclusion criteria. The mean reporting and methodologic quality SciRAP scores were 82.7 ± 6.4/100 and 87 ± 4.2/100, respectively. Within the limitations of this in vitro systematic review, it can be concluded that the TiO₂ coatings with smooth nano-structured surface topography and good wettability improve gingival cell response compared to non-coated surfaces.

Barbed Dental Ti6Al4V Alloy Screw: Design and Bench Testing

BACKGROUND CONTEXT

Dental implants are designed to replace a missing tooth. Implant stability is vital to achieving osseointegration and successful implantation. Although there are many implants available on the market, there is room for improvement.

PURPOSE

We describe a new dental implant with improved primary stability features.

STUDY DESIGN

Lab bench test studies.

METHODS

We evaluated the new implant using static and flexion-compression fatigue tests with compression loads, 35 Ncm tightening torque, displacement control, 0.01 mm/s actuator movement speed, and 9-10 Hz load application frequency, obtaining a cyclic load diagram. We applied variable cyclic loadings of predetermined amplitude and recorded the number of cycles until failure. The test ended with implant failure (breakage or permanent deformation) or reaching five million cycles for each load.

RESULTS

Mean stiffness was 1151.13 ± 133.62 SD N/mm, mean elastic limit force 463.94 ± 75.03 SD N, and displacement 0.52 ± 0.04 SD mm, at failure force 663.21 ± 54.23 SD N and displacement 1.56 ± 0.18 SD mm, fatigue load limit 132.6 ± 10.4 N, and maximum bending moment 729.3 ± 69.43 mm/N.

CONCLUSIONS

The implant fatigue limit is satisfactory for incisor and canine teeth and between the values for premolars and molars for healthy patients. The system exceeds five million cycles when subjected to a 132.60 N load, ensuring long-lasting life against loads below the fatigue limit.

Vapor-Induced Pore-Forming Atmospheric-Plasma-Sprayed Zinc-, Strontium-, and Magnesium-Doped Hydroxyapatite Coatings on Titanium Implants Enhance New Bone Formation-An In Vivo and In Vitro Investigation

OBJECTIVES

Titanium implants are regarded as a promising treatment modality for replacing missing teeth. Osteointegration and antibacterial properties are both desirable characteristics for titanium dental implants. The aim of this study was to create zinc (Zn)-, strontium (Sr)-, and magnesium (Mg)-multidoped hydroxyapatite (HAp) porous coatings, including HAp, Zn-doped HAp, and Zn-Sr-Mg-doped HAp, on titanium discs and implants using the vapor-induced pore-forming atmospheric plasma spraying (VIPF-APS) technique.

METHODS

The mRNA and protein levels of osteogenesis-associated genes such as collagen type I alpha 1 chain (COL1A1), decorin (DCN), osteoprotegerin (TNFRSF11B), and osteopontin (SPP1) were examined in human embryonic palatal mesenchymal cells. The antibacterial effects against periodontal bacteria, including Porphyromonas gingivalis and Prevotella nigrescens, were investigated. In addition, a rat animal model was used to evaluate new bone formation via histologic examination and micro-computed tomography (CT).

RESULTS

The ZnSrMg-HAp group was the most effective at inducing mRNA and protein expression of TNFRSF11B and SPP1 after 7 days of incubation, and TNFRSF11B and DCN after 11 days of incubation. In addition, both the ZnSrMg-HAp and Zn-HAp groups were effective against P. gingivalis and P. nigrescens. Furthermore, according to both in vitro studies and histologic findings, the ZnSrMg-HAp group exhibited the most prominent osteogenesis and concentrated bone growth along implant threads.

SIGNIFICANCE

A porous ZnSrMg-HAp coating using VIPF-APS could serve as a novel technique for coating titanium implant surfaces and preventing further bacterial infection.

Comparing the Long-Term Success Rates of Tooth Preservation and Dental Implants: A Critical Review

Implant therapy is considered a predictable, safe, and reliable rehabilitation method for edentulous patients in most clinical scenarios. Thus, there is a growing trend in the indications for implants, which seems attributable not only to their clinical success but also to arguments such as a more "simplified approach" based on convenience or the belief that dental implants are as good as natural teeth. Therefore, the objective of this critical literature review of observational studies was to discuss the evidence concerning the long-term survival rates and treatment outcomes, comparing endodontically or periodontally treated teeth with dental implants. Altogether, the evidence suggests that the decision between keeping a tooth or replacing it with an implant should carefully consider the condition of the tooth (e.g., amount of remaining tooth and degree of attachment loss and mobility), systemic disorders, and patient preference. Although observational studies revealed high success rates and long-term survival of dental implants, failures and complications are common. For this reason, attempts should be made to first save maintainable teeth over the long-term, instead of immediately replacing teeth with dental implants.

Osseointegration behavior of carbon fiber reinforced polyetheretherketone composites modified with amino groups: An in vivo study

Polyetheretherketone (PEEK) has become increasingly popular in dentistry and orthopedics due to its excellent chemical stability, reliable biosafety, and low elastic modulus. However, PEEK's biomechanical strength and bioactivity are limited and need to be increased as an implant material. The previous study in vitro has shown that the amino-functionalized carbon fiber reinforced PEEK (A-30%-CPEEK) possessed enhanced mechanical property and bioactivity. This study aims to evaluate the effect of amino groups modification on the osseointegration behavior of carbon fiber reinforced PEEK (30%-CPEEK) in rabbits. Herein, 30%-CPEEK and A-30%-CPEEK implant discs were implanted in rabbit skulls for 5 weeks, with pure titanium implants serving as a control. The bone-forming ability and osseointegration in vivo were systematically investigated by micro-computed tomography analysis, scanning electron microscope observation, and histological evaluation. Our results showed that all detection parameters were significantly different between the A-30%-CPEEK and 30%-CPEEK groups, favoring those in the A-30%-CPEEK, whose appraisal parameters were equal to or better than pure titanium. Therefore, this study supported the importance of amino groups in facilitating the new bone formation and bone-implant integration, suggesting that A-30%-CPEEK with enhanced osseointegration will be a promising material for dental or orthopedic implants.

Do silver/hydroxyapatite and zinc oxide nano-coatings improve inflammation around titanium orthodontic mini-screws? In vitro study

BACKGROUND

Overcoming the failure percentage of orthodontic mini-screws (OMSs), which is about 30% of overall orthodontic cases, especially in malocclusion treatment that requires orthopaedic heavy forces, is a great challenge. Bacterial infections, soft tissue and bone inflammation, and weak connections between bones and the OMS surface are among the main causalities of this failure.

OBJECTIVE

The aim of the study is to evaluate in vitro the microbiological activities of the deposited nanomaterials (Silver/hydroxyapatite nanoparticles (Ag/HA NPs) and zinc oxide nanoparticles (ZnO NPs)) in terms of microbial inhibition. In addition, the in-vitro cytotoxicity and cytocompatibility of the synthesized nano-coatings prior to their in-vivo application in animal models were tested on four types of cells, namely, fibroblasts, osteocytes, osteoblasts, and oral epithelial cells.

MATERIALS AND METHODS

Ag/HA NPs and ZnO NPs were built up onto the surface of titanium OMSs by electrochemical deposition. This electrochemical deposition was performed on 50 orthodontic mini screws and the deposited materials were characterized with the aid of scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) analysis, X-ray Diffraction (XRD) and nano-scratch test. In addition, the microbiological activities of the deposited nanomaterials were explored in vitro in terms of microbial inhibition. Furthermore, the cytotoxicity and cytocompatibility were tested on four types of cells, namely, fibroblasts, osteocytes, osteoblasts and oral epithelial cells.

RESULTS

SEM images revealed spherical Ag NPs in the range of 40-70nm in diameter, rod-shaped HA NPs and porous scaly ZnO NPs on the surface of the OMSs. XRD analysis confirmed the crystal structures of AgNPs, HA NPs, and ZnO NPs. ZnO NPs coated OMS had the highest antimicrobial activity than Ag/HA coated OMS against Gram-positive, Gram-negative and fungal strains. Moreover, after incubation, the decrease in the number of bacterial colonies was significant with ZnO and Ag/HA nanoparticles (with the greatest decrease for the former), due to the potent antibacterial effect of nanoparticles against Escherichia coli and Enterococcus faecalis. Moreover, ZnO NPs-coated OMSs showed a better cytocompatibility with oral epithelium, bone cells, and fibroblasts compared to Ag/HA NPs.

CONCLUSION

The suggested nanocoating is a promising strategy to overcome the development of an inflammatory zone around the fixed OMSs.

In-Vitro Evaluation of Photofunctionalized Implant Surfaces in a High-Glucose Microenvironment Simulating Diabetics

The present study aimed to assess the efficacy of photofunctionalization on commercially available dental implant surfaces in a high-glucose environment. Discs of three commercially available implant surfaces were selected with various nano- and microstructural alterations (Group 1—laser-etched implant surface, Group 2—titanium–zirconium alloy surface, Group 3—air-abraded, large grit, acid-etched surface). They were subjected to photo-functionalization through UV irradiation for 60 and 90 min. X-ray photoelectron spectroscopy (XPS) was used to analyze the implant surface chemical composition before and after photo-functionalization. The growth and bioactivity of MG63 osteoblasts in the presence of photofunctionalized discs was assessed in cell culture medium containing elevated glucose concentration. The normal osteoblast morphology and spreading behavior were assessed under fluorescence and phase-contrast microscope. MTT (3-(4,5 Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and alizarin red assay were performed to assess the osteoblastic cell viability and mineralization efficiency. Following photofunctionalization, all three implant groups exhibited a reduced carbon content, conversion of Ti4+ to Ti3+, increased osteoblastic adhesion, viability, and increased mineralization. The best osteoblastic adhesion in the medium with increased glucose was seen in Group 3. Photofunctionalization altered the implant surface chemistry by reducing the surface carbon content, probably rendering the surfaces more hydrophilic and conducive for osteoblastic adherence and subsequent mineralization in high-glucose environment.

Biomechanical analysis of different fixed dental restorations on short implants: a finite element study

OBJECTIVES

Although the use of short implants is becoming more common for patients with atrophic alveolar ridges, their use is still quite limited. This is due to the lack of data of long-term survival compared to standard-length implants. The aim of this study was to determine the load in the bone and implant system with different superstructures.

METHODS

Three kinds of prosthetic restorations were created on short implants based on CT-Data. Two short implants with different macro-geometries were used. The implants were inserted in idealised posterior lower mandibular segments and afterwards restored with a crown, a double splinted crown, and a bridge.

RESULTS

The analysis was performed under load of 300 N either divided between a mesial and distal point or as a point load on the pontic/mesial crown. The different design of the implant systems had a noticeable influence on the stress in the cortical bone, in the implant system, and the displacement of the superstructure as well.

CONCLUSIONS

Compared with implants of standard length, higher stresses were observed, which can lead early failure of the implant during the healing period or a late cervical bone resorption. Precise indications are essential for short implants to avoid the failure of short implants.

Clinical application of platelet-rich fibrin to enhance dental implant stability: A systematic review and meta-analysis

Objective

To investigate the effect of platelet-rich fibrin application on implant stability.

Study design

Five databases, namely, PubMed, Embase, Web of Science, Wiley, and China National Knowledge Infrastructure, were searched for reports published up to November 20, 2022. Randomized controlled trials (RCT), including parallel RCTs and split-mouth RCTs, with at least 10 patients/sites were considered for inclusion.

Results

After screening based on the inclusion criteria, ten RCTs were included. Low heterogeneity was observed in study characteristics, outcome variables, and estimation scales (I2 = 27.2%, P = 0.19). The qualitative and meta-analysis results showed that PRF increased the effect of implant stabilizers after implant surgery.

Conclusions

The results of the present systematic review and meta-analysis suggest that PRF can increase implant stability after implant surgery. PRF may also have a role in accelerating bone healing and tends to promote new bone formation at the implant site.

Nanostructured Calcium-Incorporated Surface Compared to Machined and SLA Dental Implants-A Split-Mouth Randomized Case/Double-Control Histological Human Study

Background: Implant surface topography is a key element in achieving osseointegration. Nanostructured surfaces have shown promising results in accelerating and improving bone healing around dental implants. The main objective of the present clinical and histological study is to compare, at 4 and 6 weeks, (w) bone-to-implant contact in implants having either machined surface (MAC), sandblasted, large grit, acid-etched implant surface (SLA) medium roughness surface or a nanostructured calcium-incorporated surface (XPEED®). Methods: 35 mini-implants of 3.5 × 8.5 mm with three different surface treatments (XPEED® (n = 16)—SLA (n = 13)—MAC (n = 6), were placed in the posterior maxilla of 11 patients (6 females and 5 males) then, retrieved at either 4 or 6w in a randomized split-mouth study design. Results: The BIC rates measured at 4w and 6w respectively, were: 16.8% (±5.0) and 29.0% (±3.1) for MAC surface; 18.5% (±2.3) and 33.7% (±3.3) for SLA surface; 22.4% (±1.3) and 38.6% (±3.2) for XPEED® surface. In all types of investigated surfaces, the time factor appeared to significantly increase the bone to implant contact (BIC) rate (p < 0.05). XPEED® surface showed significantly higher BIC values when compared to both SLA and MAC values at 4w (p < 0.05). Also, at 6w, both roughened surfaces (SLA and XPEED®) showed significantly higher values (p < 0.05) than turned surface (MAC). Conclusions: Nanostructured Calcium titanate coating is able to enhance bone deposition around implants at early healing stages.

Evaluation of the different exposure parameters for the accurate diagnosis of peri-implantitis severity in digital panoramic radiography

BACKGROUND

To evaluate the accuracy of the diagnosis of peri-implant bone defects' severities in digital panoramic radiographs obtained at different tube voltage and/or tube current settings.

MATERIAL AND METHODS

Two different sizes of peri-implant bone defects (type 1 and type 2) were prepared after the implants were inserted into 29 bovine rib blocks. Digital panoramic radiographs were obtained at eight different tube voltage and/or tube current settings for all rib blocks. Implant images were cropped separately. The average intensity value (AIV) of cropped images were analyzed using Adobe Photoshop CC software. The Kruskal-Wallis H test was used to compare AIVs. All cropped images were evaluated using a five-point Likert scale for the likelihood of a bone defect being absent or present. The weighted kappa values were calculated to compare observer agreement and ROC analysis was performed to determine the appropriate exposure parameters.

RESULTS

The lowest AIV was obtained at 72 kV/6.3 mA (92.162±16.016), and the highest AIV was obtained at 60 kV/3.2 mA (179.050±13.823). The Kruskal-Wallis H test showed significant differences in the AIVs according to the exposure parameters (p<0.001). The kappa coefficient for the inter-observer agreement was excellent (0.864, p<0.001). The AUC values for type 1 defects ranged from 0.778 and 0.860; for type 2 defects ranged from 0.920 and 0.967. The AUC value of type 1 defects was slightly better in panoramic images obtained with high kV and low mA levels (72 kV/3.2 mA), compared to others.

CONCLUSIONS

In daily clinical routine, peri-implant bone defects might be evaluated by panoramic radiographs obtained with all kV and mA values tested. However, to avoid misdiagnosing and for better accuracy, panoramic radiographs obtained with high kV and low mA levels suitable for patients should be used, especially in the detection of small or initial bone defects.

CBCT Analysis of Edentulous Mandibular Symphysis in Iraqi Patients for Treatment with Implant-Supported Overdentures. Cross-Sectional Single-Center Study

Background

Overdentures supported by dental implants are a useful treatment strategy for patients with edentulous mandibles. The aim of this study was to evaluate certain characteristics of the mandibular symphyseal edentulous cases for dental implant treatment using CBCT; and if it is associated with gender differences.

Methods

Ninety patients (45 females and 45 males) were included in this investigation. A section along the midline of each CBCT image was chosen for the edentulous symphyseal area. Symphysis height, width, and cortical thickness was measured for each patient. Bone density were calculated at four points A two-sample Student's t-test and Pearson correlation were used for statistical analysis.

Results

Males had a considerably greater symphysis height (26.66±6.21 mm) than females (24.07±5.00 mm) (p = 0.02). Similar results were found for bone width; males had greater means than females. In case of cortical bone thickness; males had thicker bone cortex in the buccal region than females (p = 0.01). While the difference in bone density between genders was small. However, a positive relationship was recorded between symphysis height and width.

Conclusion

Height and width of the mandibular symphysis were influenced by gender in edentulous patients, with men showing higher measurements. The reduction of symphyseal height decreased concurrently with the width after teeth were lost, while bone density was maintained in both genders with no difference between them. The lingual cortical bone is significantly thicker than the buccal cortex at the lower part of the symphysis.

Effect of commercially pure titanium implant coated with calcium carbonate and nanohydroxyapatite mixture on osseointegration

In this research, rabbit femurs were implanted with CP Ti screws coated with a combination of CaCO3 and nanohydroxyapatite, and the effect on osseointegration was assessed using histological and histomorphometric examination at 2 and 6 weeks. CaCO3 and nanohydroxyapatite were combined with the EPD to coat the surfaces of the CP Ti screws. The femurs of five male rabbits were implanted with coated and uncoated implant screws. Healing time was divided into two groups (2 and 6 weeks). After 2 and 6 weeks of implantation, the histological examination revealed an increase in the growth of bone cells for coated screws, and the histomorphometric analysis revealed an increase in the percentage of new bone formation (after 6 weeks, 5.08% for coated implants and 3.66% for uncoated implants). In addition, the uncoated implant, the CP Ti implant coated with a combination of CaCO3 and nanohydroxyapatite, stimulated early bone development after two weeks and mineralization and maturation after six weeks.

Influence of the roughness of dental implants obtained by additive manufacturing on osteoblastic adhesion and proliferation: A systematic review

Objective

Critically analyzed the existing literature to answer the question "What is the influence of roughness of surfaces for dental implants obtained by additive manufacturing compared to machined on osteoblastic cell adhesion and proliferation?"

Design

This systematic review followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered in the Open Science Framework. The personalized search strategy was applied to Embase, Pub Med, Scopus, and Science Direct databases and Google Scholar and ProQuest grey literature. The selection process was carried out in two stages independently by two reviewers according to the eligibility criteria. The risk of bias was analyzed using a checklist of important parameters to be considered.

Results

When applying the search strategy on databases 223 articles were found, after removing the duplicates, 171 were analyzed by title and abstract of which 25 were selected for full reading, of these, 6 met the eligibility criteria. 2 studies were included from the reference list totaling 8 articles included in this systematic review and none were included from the Grey Literature. 7 had a low risk of bias and 1 moderate.

Conclusions

1) Roughness is a property that must be analyzed and correlated with the chemical composition, intrinsic to the alloy and resulting from the surface treatment; morphology of topographic peaks and valleys; printing technique and its parameters; 2) Need for more studies on the biomolecular level to elucidate the mechanism by which the roughness and the morphology of topographical peaks and valleys descriptive of roughness influence osteoblastic adhesion and proliferation.

Effects of Micro-Arc Oxidation Discharge Parameters on Formation and Biomedical Properties of Hydroxyapatite-Containing Flower-like Structure Coatings

The micro-arc oxidation (MAO) process was used to prepare hydroxyapatite-containing flower-like structure coatings on commercially pure titanium substrates with various values of the applied voltage (330, 390, 450 V), applied current (0.4, 0.5, 0.6 A), and duration time (1, 3, 5 min). It was found that the surface morphology of the coatings was determined primarily by the applied voltage. A voltage of 330 V yielded a flower-like/plate-like structure, while voltages of 390 V and 450 V produced a flower-like structure and a porous morphology, respectively. The applied current and duration time mainly affected the coating formation speed and petal size of the flower-like structures, respectively. The coatings prepared using voltages of 330 V and 390 V (0.6 A, 5 min) both contained Ti, TiO₂-A (anatase), TiO₂-R (rutile), DCPD (CaHPO₄·2H₂O, calcium hydrogen phosphate), and hydroxyapatite (HA). However, the latter coating contained less DCPD and had a higher HA/DCPD ratio and a Ca/P ratio closer to the ideal value of HA. The coating prepared with a voltage of 450 V consisted mainly of Ti, TiO₂-A, TiO₂-R, and CaTiO₃. For the coatings prepared with a voltage of 390 V, the flower-like structures consisted mainly of HA-containing compounds. DCPD plate-like structures were observed either between the HA-containing flower-like structures (330 V samples) or within the flower-like structures themselves (390 V samples). The coating surfaces with flower-like/plate-like or flower-like structures had a greater roughness, which increased their hydrophilicity and resulted in superior bioactivity (SBF immersion) and biocompatibility (MG-63 cell culture). The optimal biomedical performance was found in the 390 V coating due to its flower-like structure and high HA/DCPD ratio.

Selective Grafting of Protease-Resistant Adhesive Peptides on Titanium Surfaces

In orthopedic, dental, and maxillofacial fields, joint prostheses, plates, and screws are widely used in the treatment of problems related to bone tissue. However, the use of these prosthetic systems is not free from complications: the fibrotic encapsulation of endosseous implants often prevents optimal integration of the prostheses with the surrounding bone. To overcome these issues, biomimetic titanium implants have been developed where synthetic peptides have been selectively grafted on titanium surfaces via Schiff base formation. We used the retro-inverted sequence (DHVPX) from [351-359] human Vitronectin and its dimer (D2HVP). Both protease-resistant peptides showed increased human osteoblast adhesion and proliferation, an augmented number of focal adhesions, and cellular spreading with respect to the control. D2HVP-grafted samples significantly enhance Secreted Phosphoprotein 1, Integrin Binding Sialoprotein, and Vitronectin gene expression vs. control. An estimation of peptide surface density was determined by Two-photon microscopy analysis on a silanized glass model surface labeled with a fluorescent analog.

Zoledronic Acid Implant Coating Results in Local Medullary Bone Growth

Osteoarthritis (OA) can necessitate surgical interventions to restore the function of the joint in severe cases. Joint replacement surgery is one of the procedures implemented to replace the damaged joint with prosthetic implants in severe cases of OA. However, after successful implantation, a fraction of OA patients still require revision surgery due to aseptic prosthetic loosening. Insufficient osseointegration is one of the factors that contribute to such loosening of the bone implant, which is commonly made from titanium-based materials. Zoledronic acid (ZA), a potent bisphosphonate agent, has been previously shown to enhance osseointegration of titanium implants. Herein, we fabricated ZA/Ca composites using a reverse microemulsion method and coated them with 1,2-dioleoyl-sn-glycero-3-phosphate monosodium salt (DOPA) to form ZA/Ca/DOPA composites. Titanium alloy screws were subsequently dip-coated with a suspension of the ZA/Ca/DOPA composites and poly(lactic-co-glycolic) acid (PLGA) in chloroform to yield Za/PLGA-coated screws. The coated screws exhibited a biphasic in vitro release profile with an initial burst release within 48 h, followed by a sustained release over 1 month. To assess their performance in vivo, the Za/PLGA screws were then implanted into the tibiae of Sprague-Dawley rats. After 8 weeks, microCT imaging showed new bone growth along the medullary cavity around the implant site, supporting the local release of ZA to enhance bone growth around the implant. Histological staining further confirmed the presence of new mineralized medullary bone growth resembling the cortical bone. Such local medullary growth represents an opportunity for future studies with alternative coating methods to fine-tune the local release of ZA from the coating and enhance complete osseointegration of the implant.

Improvement of osseointegration efficacy of titanium implant through plasma surface treatment

A novel plasma treatment source for generating cylindrical plasma on the surface of titanium dental implants is developed herein. Using the titanium implant as an electrode and the packaging wall as a dielectric barrier, a dielectric barrier discharge (DBD) plasma was generated, allowing the implant to remain sterile. Numerical and experimental investigations were conducted to determine the optimal discharge conditions for eliminating hydrocarbon impurities, which are known to degrade the bioactivity of the implant. XPS measurement confirmed that plasma treatment reduced the amount of carbon impurities on the implant surface by approximately 60%. Additionally, in vitro experiments demonstrated that the surface treatment significantly improved cell adhesion, proliferation, and differentiation. Collectively, we proposed a plasma treatment source for dental implants that successfully removes carbon impurities and facilitate the osseointegration of SLA implants.

Factors Influencing the Survival Rate of Teeth and Implants in Patients after Tumor Therapy to the Head and Neck Region-Part 2: Implant Survival

During prosthetic rehabilitation after tumor therapy (TT) in the head and neck region, the dentist must assess whether the prognosis of the remaining teeth is sufficiently good or whether implants should be used to anchor dentures. Thus, the aim of the present study was to compare the survival rate of teeth and implants after TT and to evaluate factors potentially influencing implant survival. One hundred fifteen patients (male: 70.3%; mean age: 63.2 ± 12.4 years) having received dental treatment before and after TT at the Martin Luther University Halle-Wittenberg were enrolled in the study. Clinical examination including assessment of dental status and stimulated salivary flow rate was performed. Information about disease progression and therapy was retrieved from medical records. After TT, from a total of 1262 teeth, 27.2% had to be extracted. Of 308 implants inserted after TT, 7.0% were lost. Teeth exhibited lower 5-year survival probability (76.8%) than implants (89.9%; p = 0.001). The risk of loss (RL) of implants increased with age, nicotine use, intraoral defects, and RCT. Radiotherapy did not independently increase the RL. Thus, implants seem to be a reliable treatment option in case of progressive tooth decay after TT, particularly after RT.

Clinical outcomes of different implant types in mandibular bar-retained overdentures: a retrospective analysis with up to 20 years follow-up

PURPOSE

To determine the clinical and radiological outcomes of hybrid-design- (HD) and bone-level (BL) implants for bar-retained mandibular implant-overdentures (IODs).

METHODS

For this retrospective study, edentulous patients who had received maxillary complete dentures and mandibular bar-retained IODs were invited for a follow-up assessment. Implant survival, implant success and health of peri-implant tissues were assessed on an implant level-based analysis. Patient-based parameters served to identify risk factors for peri-implant bone loss, presence of peri-implantitis and success.

RESULTS

Eighty patients (median age 72.72 [67.03; 78.81] years, 46 females) with 180 implants (median follow-up 12.01 [10.82; 21.04] years) were assessed. There was no difference concerning the rate of implant failure (p = 0.26), or peri-implantitis (p = 0.97) between HD and BL implants. Solely in one study group, there was the presence of peri-implant pus. Implant success was higher in BL implants with one group being notably higher than the comparing groups (p = 0.045). For bone loss, a width of keratinized mucosa (KM) ≤ 1 mm (p = 0.0006) and the presence of xerostomia (p = 0.09) were identified as risk factors. Smoking (p = 0.013) and a higher body mass index (BMI) (p = 0.03) were a risk factor for peri-implantitis. As risk factors for reduced implant success, a small width of KM (p = 0.003) and the presence of xerostomia (p = 0.007) were identified.

CONCLUSIONS

For mandibular bar-retained IODs, both BL and HD implants are mostly successful. A minimum of 1 mm KM around implants and normal salivary flow are relevant factors for implant success and stable peri-implant bone levels. Smoking and a high BMI are potential risk factors for peri-implantitis.

Benchmark performance of anodized vs. sandblasted implant surfaces in an acute dehiscence type defect animal model

OBJECTIVES

Crestal bone formation represents a crucial aspect of the esthetic and biological success of dental implants. This controlled preclinical study analyzed the effect of implant surface and implant geometry on de novo crestal bone formation and osseointegration.

MATERIALS AND METHODS

Histological and histomorphometrical analysis was performed to compare three implant groups, that is, (1) a novel, commercially available, gradient anodized implant, (2) a custom-made geometric replica of implant "1," displaying a superhydrophilic micro-rough large-grit sandblasted and acid-etched surface, and (3) a commercially available implant, having the same surface as "2" but a different implant geometry. The study applied a standardized buccal acute-type dehiscence model in minipigs with observation periods of 2 and 8 weeks of healing.

RESULTS

The amount of newly formed crestal bone (BATA) around control groups (2) and (3) was significantly increased when compared to the test group (1) at the 8 weeks of healing time point. Similar results were obtained for all parameters related to osseointegration and direct bone apposition, to the implant surface (dBIC, VBC, and fBIC), demonstrating superior osseointegration of the moderately rough, compared to the gradient anodized functionalization. After 2 weeks, the osseointegration (nBIC) was found to be influenced by implant geometry with group (3) outperforming groups (1) and (2) on this parameter. At 8 weeks, nBIC was significantly higher for groups (2) and (3) compared to (1).

CONCLUSIONS

The extent (BATA) of de novo crestal bone formation in the acute-type dehiscence defects was primarily influenced by implant surface characteristics and their ability to promote osseointegration and direct bone apposition. Osseointegration (nBIC) of the apical part was found to be influenced by a combination of surface characteristics and implant geometry. For early healing, implant geometry may have a more pronounced effect on facilitating osseointegration, relative to the specific surface characteristics.

Effect of Titanium and Zirconia Nanoparticles on Human Gingival Mesenchymal Stromal Cells

Nano- and microparticles are currently being discussed as potential risk factors for peri-implant disease. In the present study, we compared the responses of human gingival mesenchymal stromal cells (hG-MSCs) on titanium and zirconia nanoparticles (<100 nm) in the absence and presence of Porphyromonas gingivalis lipopolysaccharide (LPS). The primary hG-MSCs were treated with titanium and zirconia nanoparticles in concentrations up to 2.000 µg/mL for 24 h, 72 h, and 168 h. Additionally, the cells were treated with different nanoparticles (25−100 µg/mL) in the presence of P. gingivalis LPS for 24 h. The cell proliferation and viability assay and live−dead and focal adhesion stainings were performed, and the expression levels of interleukin (IL)-6, IL-8, and monocyte chemoattractant protein (MCP)-1 were measured. The cell proliferation and viability were inhibited by the titanium (>1000 µg/mL) but not the zirconia nanoparticles, which was accompanied by enhanced apoptosis. Both types of nanoparticles (>25 µg/mL) induced the significant expression of IL-8 in gingival MSCs, and a slightly higher effect was observed for titanium nanoparticles. Both nanoparticles substantially enhanced the P. gingivalis LPS-induced IL-8 production; a higher effect was observed for zirconia nanoparticles. The production of inflammatory mediators by hG-MSCs is affected by the nanoparticles. This effect depends on the nanoparticle material and the presence of inflammatory stimuli.

Comparative Evaluation of Implants with Different Surface Treatments Placed in Human Edentulous Mandibles: A 1-Year Prospective Study

The aims of this study were to analyze prospectively and comparatively the peri-implant bone crest levels, bone density, stability and success rate of implants with different surface treatments in human edentulous mandibles. Twenty edentulous patients were selected. Four different implants were placed between the mental foramen. Four groups were evaluated: (1) laser-modified surface (LASER), (2) surface modified by laser with deposition of apatites (LASER + HA), (3) surface modified by double acid etching (ACID, Implacil De Bortoli) and (4) surface modified by sandblasting and acid etching (SLActive®, Straumann). Clinical, radiographic, resonance frequency and tomographic analyses were used. After 4 months, mandibular fixed implant prostheses were installed. Clinical and radiographic analyses were performed at times T0 (immediately after implant placement), T1 (15 days), T2 (30 days), T3 (60 days), T4 (90 days), T5 (120 days), T6 (180 days) and T7 (360 days), post-implant placement. The resonance frequency analysis (RFA) was measured at T0, T4, T6 and T7. The tomographic analysis was performed at T0, T4 and T7. In the radiographic bone density analysis, a statistical difference was found between the SLActive® and LASER + HA groups at T4 (p < 0.05). Statistical differences were observed in RFA at T4 (90 days), between the SLActive® and LASER groups (p < 0.05) and between the SLActive® and LASER + HA groups (p < 0.05). At T6 and T7, statistical differences were found between the SLActive® group and all other implant surfaces (p < 0.01). The experimental surfaces analyzed showed encouraging positive outcomes compared to those of the SLActive® surface. Long-term follow-up should be performed to confirm these results.