Clinical efficacy,bone density,and follow-up in implant and orthodontic treatment for inclined adjacent teeth

BACKGROUND Tooth defects can cause elongation of occlusal teeth,leading to insufficient repair space.The combination of dental implant restoration and orthodontic treatment of oblique adjacent teeth has a significant therapeutic effect.AIM To explore clinical efficacy,bone density,and follow-up of implant and orthodontic treatment for patients with inclined adjacent teeth.METHODS In total,98 patients with oblique adjacent teeth were randomly assigned to implant restoration combined with orthodontic treatment(group A,n=49)or to receive implant restoration alone(group B,n=49).Changes in alveolar ridge bone density and apical bone density were observed before and after treatment in the two groups.Changes in chewing function and language function were compared between the two groups of patients.Follow-up lasted for 12 mo after repair to observe any adverse reactions in the oral cavity.RESULTS The clinical effective rates of group A and group B were 97.96%and 85.71%,respectively,with group A having a higher clinical effective rate than group B.After treatment,the bone density of the alveolar ridge and apical bone in both groups decreased compared to before treatment,while the chewing and language functions improved.The changes in various indicators in group A were more significant.After treatment,the satisfaction rate of group A(97.96%)was higher than that of group B(79.59%).The incidence of adverse reactions in group A(2.04%)was lower than that in group B(24.49%).CONCLUSION The amalgamation of implant restoration and orthodontic treatment for adjacent tilted teeth demonstrates notable clinical efficacy,diminishes alveolar bone resorption,and fosters patient functional rehabilitation while exhibiting negligible adverse reactions.

Comparison between Two Different Manufactured Forms of β-Tricalcium Phosphate Bone Graft in Immediate Implant Placement

Objectives: The aim of this study was to compare the efficacy of using the synthetic β-TCP bone grafting material in two different manufacturing forms (putty and granular) in grafting the jumping zone around immediate implant. Patients and Method: A randomized controlled clinical and radiographic trial was conducted on 24 male patients aged from 45 - 55 with badly decayed non-restorable teeth in the posterior mandibular area and seeking for receiving immediate dental implant directly after extraction. Vertical bone height and bone density were taken at time of implant placement and 6 months postoperatively. Results: The Putty form group and the Granular form group did not differ statistically in terms of age, post-operative complications, or implant outcome six months postoperatively. Additionally, there was a statistically significant increase in Putty form group compared to the Granular form group regarding Marginal bone loss 6 months postoperatively, but there was no statistically significant difference between the Putty form group and the Granular form group regarding Bone density by CBCT. Conclusion: The β-TCP Putty material, compared to β-TCP granular, displayed better surgical handling properties, and both forms had no adverse effect on bone formation, bone tissue maturation or graft volume stability, The β-TCP granular material, compared to β-TCP putty, displayed less marginal bone loss 6 months post-operatively.

3D printing of PEEK–cHAp scaffold formedical bone implant

The major drawback associated with PEEK implants is their biologically inert surface,which caused unsatisfactory cellular response and poor adhesion between the implants and surrounding soft tissues against proper bone growth.In this study,polyetheretherketone(PEEK)was incorporated with calcium hydroxyapatite(cHAp)to fabricate a PEEK-cHAp biocomposite,using the fused deposition modeling(FDM)method and a surface treatment strategy to create microporous architectures onto the filaments of PEEK lattice scaffold.Also,nanostructure and morphological tests of the PEEK-cHAp biocomposite were modeled and analyzed on the FDM-printed PEEK-cHAp biocomposite sample to evaluate its mechanical and thermal strengths as well as in vitro cytotoxicity via a scanning electron microscope(SEM).A technique was used innovatively to create and investigate the porous nanostructure of the PEEK with controlled pore size and distribution to promote cell penetration and biological integration of the PEEK-cHAp into the tissue.In vivo tests demonstrated that the surface-treated micropores facilitated the adhesion of newly regenerated soft tissues to form tight implant-tissue interfacial bonding between the cHAp and PEEK.The results of the cell culture depicted that PEEK-cHAp exhibited better cell proliferation attachment spreading and higher alkaline phosphatase activity than PEEK alone.Apatite islands formed on the PEEK-cHAp composite after immersion in simulated body fluid of Dulbecco’s modified Eagle medium(DMEM)for 14 days and grew continuously with more or extended periods.The microstructure treatment of the crystallinity of PEEK was comparatively and significantly different from the PEEK-cHAp sample,indicating a better treatment of PEEK-cHAp.The in vitro results obtained from the PEEK-cHAp biocomposite material showed its biodegradability and performance suitability for bone implants.This study has potential applications in the field of biomedical engineering to strengthen the conceptual knowledge of FDM and medical implants fabricated from PEEK-cHAp biocomposite materials.

Marginal bone loss around non-submerged implants is associated with salivary microbiome during bone healing

Marginal bone loss during bone healing exists around non-submerged dental implants. The aim of this study was to identify the relationship between different degrees of marginal bone loss during bone healing and the salivary microbiome. One hundred patients were recruited, and marginal bone loss around their implants was measured using cone beam computed tomography during a 3-month healing period. The patients were divided into three groups according to the severity of marginal bone loss.Saliva samples were collected from all subjected and were analysed using 16 SMiSeq sequencing. Although the overall structure of the microbial community was not dramatically altered, the relative abundance of several taxonomic groups noticeably changed. The abundance of species in the phyla Spirochaeta and Synergistetes increased significantly as the bone loss became more severe. Species within the genus Treponema also exhibited increased abundance, whereas Veillonella, Haemophilus and Leptotrichia exhibited reduced abundances, in groups with more bone loss. Porphyromonasgingivalis, Treponemadenticola and Streptococcus intermedius were significantly more abundant in the moderate group and/or severe group. The severity of marginal bone loss around the non-submerged implant was associated with dissimilar taxonomic compositions. An increased severity of marginal bone loss was related to increased proportions of periodontal pathogenic species. These data suggest a potential role of microbes in the progression of marginal bone loss during bone healing.

Influence of Geometric Design Variable and Bone Quality on Stress Distribution for Zirconia Dental Implants-A 3D Finite Element Analysis

This study aims to investigate the effects of variable thread pitch on stress distribution in bones of different bone qualities under two different loading conditions(Vertical,and Horizontal)for a Zirconia dental implant.For this purpose,a three dimensional finite element model of the mandibular premolar section and three single threaded implants of 0.8 mm,1.6 mm,2.4 mm pitch was designed.Finite element analysis software was used to develop the model and three different bone qualities(Type II,Type III,and Type IV)were prepared.A vertical load of 200 N,and a horizontal load of 100 N was applied at the abutment surface.The von-Mises stress criterion was used to analyze the results.The crestal bony-region of the mandibular section was subjected to maximum von-Mises stresses for all bone qualities.The outcome of this study indicates that,horizontal loading had more influence on stress distribution than vertical loading,regardless of the bone qualities and pitch values.Varying the dental implant pitch does not cause any decrease in stress distribution in bone,when the bone density decreased.The study concluded that implants with minimum pitch values induced lesser stress values at the implant-bone interface.

Approaches to promoting bone marrow mesenchymal stem cell osteogenesis on orthopedic implant surface

Bone marrow-derived mesenchymal stem cells(BMSCs)play a critical role in the osseointegration of bone and orthopedic implant.However,osseointegration between the Ti-based implants and the surrounding bone tissue must be improved due to titanium’s inherent defects.Surface modification stands out as a versatile technique to create instructive biomaterials that can actively direct stem cell fate.Here,we summarize the current approaches to promoting BMSC osteogenesis on the surface of titanium and its alloys.We will highlight the utilization of the unique properties of titanium and its alloys in promoting tissue regeneration,and discuss recent advances in understanding their role in regenerative medicine.We aim to provide a systematic and comprehensive review of approaches to promoting BMSC osteogenesis on the orthopedic implant surface.

Animal Modelling of Lumbar Corpectomy and Fusion and in vivo Growth of Spine Supporting Bone by Titanium Cage Implants: An Experimental Study

In this study a lumbar spinal fusion animal model is established to assess the effect of spinal fusion cage,and explore theminimum area ratio of titanium cage section to vertebral section that ensures bone healing and biomechanical property.Lumbarcorpectomy was conducted by posterolateral approach with titanium cage implantation combined with plate fixation.Titaniumcages with the same length but different diameters were used.After implantation of titanium cages,the progress of bone healingwas observed and the bone biomechanical properties were measured,including deformation and displacement in axial compression,flexion,extension,and lateral bending motion.The factors affecting the in vivo growth of spine supporting body wereanalyzed.The results show that the area ratio of titanium cage section to vertebral section should reach 1/2 to ensure the bonehealing,sufficient bone intensity and biomechanical properties.Some bone healing indicators,such as BMP,suggest that there isa relationship between the peak time and the peak value of bone formation and metabolism markers and the bone healing strength.

Bone cement implantation syndrome during hip replacement in a patient with pemphigus and Parkinson’s disease: A case report

BACKGROUND Bone cement implantation syndrome(BCIS)is characterized by hypotension,arrhythmia,diffuse pulmonary microvascular embolism,shock,cardiac arrest,any combination of these factors,or even death following bone cement implantation.CASE SUMMARY An 80-year-old patient with pemphigus and Parkinson’s disease underwent total hip replacement under spinal subarachnoid block and developed acute pulmonary embolism after bone cement implantation.The patient received mask mechanical ventilation with a continuous intravenous infusion of adrenaline(2μg/mL)at a rate of 30 mL/h.Subsequently,the symptoms of BCIS were markedly alleviated,and the infusion rate of adrenaline was gradually reduced until the infusion was completely stopped 45 min later.The patient was then transferred to the Department of Orthopedics,and anticoagulation therapy began at 12 h postoperatively.No other complications were observed.CONCLUSION This is a rare case of BCIS in a high-risk patient with pemphigus and Parkinson’s disease.

The Behavior of New Hydrophilic Composite Bone Cements for Immediate Loading of Dental Implant

We introduced the hydrophilic groups to acrylic bone cement to improve compliance and achieve more interdigitation between the bone and the acrylic bone cement in order to create better substrates for immediate loading. FTIR-ATR, contact angle, and maximum breach torque were employed for measurement. The results reveal that the introduction of hydrophilic functional groups has increased PMMA＇s surface hydrophilicity after contact angle test. FTIR-ATR results suggest the hydrophilic groups participate in the polymerization reactions, and maximum breach torque of the hydrophilic acrylic bone cements is near 110 Ncm torque. Those effects make it possible for conventional acrylic bone cement application in immediate loading of dental implant.

Advances in biocermets for bone implant applications

As two promising biomaterials for bone implants,biomedical metals have favorable mechanical properties and good machinability but lack of bioactivity;while bioceramics are known for good biocompatibility or even bioactivity but limited by their high brittleness.Biocermets,a kind of composites composing of bioceramics and biomedical metals,have been developed as an effective solution by combining their complementary advantages.This paper focused on the recently studied biocermets for bone implant applications.Concretely,biocermets were divided into ceramic-based biocermets and metal-based biocermets according to the phase percentages.Their characteristics were systematically summarized,and the fabrication methods for biocermets were reviewed and compared.Emphases were put on the interactions between bioceramics and biomedical metals,as well as the performance improvement mechanisms.More importantly,the main methods for the interfacial reinforcing were summarized,and the corresponding interfacial reinforcing mechanisms were discussed.In addition,the in vitro and in vivo biological performances of biocermets were also reviewed.Finally,future research directions were proposed on the advancement in component design,interfacial reinforcing and forming mechanisms for the fabrication of high-performance biocermets.

In vivo analysis of post-joint-preserving surgery fracture of 3D-printed Ti-6Al-4V implant to treat bone cancer

Cancer growth in the bone due to its random shape disables bone strength and thus changes its capacity to support body weight or muscles,which can crucially affect the quality of human life in terms of normal walking or daily activities.For successful patient recovery,it is necessary to remove the cancer-affected minimal bone area and quickly replace it with a biocompatible metal implant within less than 2 weeks.An electron beam-melted Ti-6Al-4V implant was designed and applied in a patient to preserve the natural knee joint close to the bone tumor.The developed implant fits the bone defect well,and the independent ambulatory function of the natural knee joint was restored in the patient within six weeks after surgery.A delayed fracture occurred six months after the successful replacement of cancer-affected bone with Ti-6Al-4V implant at the proximal meshed junction of the implant because of a minor downward slip.Microstructural,mechanical,and computational analyses were conducted for the fractured area to find the main reason for the delayed fracture.Our findings pertaining to the mechanical and material investigation can help realize the safe implantation of the three-dimensionally printed titanium implant to preserve the natural joints of patients with massive bone defects of the extremities.

The Stability Analysis of Implants Installed in Osteotomies with Different Types of Controlled Bone Defects

The stability parameters of implants （ITV, ISQ ＆ PTV） according to different sizes of controlled bone defects made in implant osteotomies were analyzed and the correlation among the three kinds of implant stability parameters was tested in this study. 45 tapped screw-type dental implants were inserted in three types of implant osteotomies made in 8 fresh-frozen pig femoral bones： Typel - without coronal bone defect, Type2 - with 3 mm coronal bone defects, and Type3 - with 6 mm coronal bone defects. The insertion torque values, ISQ ＆ PTV of implants were measured and analyzed statistically. It is concluded that the circumferential coronal bone defects statistically influence the primary stability of implants; ITV, ISQ and PTV are suitable and available to detect the peri-implant coronal bone defects in 3 mm increments, and ITV and PTV are more sensitive to coronal cortical bone loss. There was a strong correlation between ITV and ISQ.

Systemic modulation of skeletal mineralization by magnesium implant promoting fracture healing: Radiological exploration enhanced with PCA-based machine learning in a rat femoral model

The clinical application of magnesium(Mg)and its alloys for bone fractures has been well supported by in vitro and in vivo trials.However,there were studies indicating negative effects of high dose Mg intake and sustained local release of Mg ions on bone metabolism or repair,which should not be ignored when developing Mg-based implants.Thus,it remains necessary to assess the biological effects of Mg implants in animal models relevant to clinical treatment modalities.The primary purpose of this study was to validate the beneficial effects of intramedullary Mg implants on the healing outcome of femoral fractures in a modified rat model.In addition,the mineralization parameters at multiple anatomical sites were evaluated,to investigate their association with healing outcome and potential clinical applications.Compared to the control group without Mg implantation,postoperative imaging at week 12 demonstrated better healing outcomes in the Mg group,with more stable unions in 3D analysis and high-mineralized bridging in 2D evaluation.The bone tissue mineral density(TMD)was higher in the Mg group at the non-operated femur and lumbar vertebra,while no differences between groups were identified regarding the bone tissue volume(TV),TMD and bone mineral content(BMC)in humerus.In the surgical femur,the Mg group presented higher TMD,but lower TV and BMC in the distal metaphyseal region,as well as reduced BMC at the osteotomy site.Principal component analysis(PCA)-based machine learning revealed that by selecting clinically relevant parameters,radiological markers could be constructed for differentiation of healing outcomes,with better performance than 2D scoring.The study provides insights and preclinical evidence for the rational investigation of bioactive materials,the identification of potential adverse effects,and the promotion of diagnostic capabilities for fracture healing.

Mechanical Experiment for 3D Printing of Titanium Bone Bionic Dental Implants

[Objectives] To explore the flexural strength of 3D printed titanium bone bionic dental implants and provide a scientific basis for the clinical application of 3D printed porous bionic bone dental implants. [Methods] The cone-beam CT( CBCT) image information of 20 premolars extracted by orthodontic requirement was collected,and a new porous bone bionic dental implant was produced using modeling software and 3D printer. The premolars were divided into two groups( A and B). The universal testing machine was used to test the flexural strength of the two groups and the difference in flexural strength between the two groups was compared through statistics. [Results]Twenty 3D printed porous titanium bone bionic implants were accurately produced; the morphology of group A and group B were extremely similar to each other; the average flexural strength of group A was 2 767. 92 N,while the average flexural strength of group B was 778. 77 N,showing that the average flexural strength of group A was significantly higher than that of group B,and the difference was statistically significant( P < 0. 05).[Conclusions]The personalized porous structure root implants produced by 3D printing technology are very similar to the target tooth morphology,and show high accuracy and small error of production. Besides,the flexural strength of 3D printed personalized porous structure root implants can fully meet the requirements of the maximum occlusal force for dental implant restoration. It is expected to provide a scientific basis for clinical application of 3 D printed porous bionic bone tooth implants.

A Comparative Study of Bone Resorption between Implant Placement Sites and Non-Implant Placement Sites after Autogenous Block Bone Grafts in the Anterior Maxilla

The aim of this study was to compare the bone resorption differences between implant placement sites (IPS) and non-implant placement sites (NIPS) after autogenous block bone grafts in the anterior maxilla. Fourteen patients (58 edentulous sites) with alveolar atrophy in the anterior maxilla were treated with autogenous block bone grafts. CBCT examinations were performed at 1 month before surgery (T0), immediately after surgery (T1), 3 to 4 months after surgery (T2), 6 to 7 months after surgery before implant placement (T3), 12 to 13 months after surgery (T4), and the longest follow-up point (T5). Alveolar crestal and basal bone width (ACBW, ABBW), and alveolar bone height (ABH) were measured and divided into IPS (30 sites) and NIPS (28 sites). All results were compared by the Wilcoxon Signed Rank test. The bone resorption changes for both groups were the same. For these three parameters, ACBW didn’t change significantly from T2 to T3 and T4 to T5, ABBW didn’t change at every period from T2 to T5, and ABH didn’t change from T4 to T5. The bone resorption volume of ACBW and ABH in NIPS were more than in IPS after implant placement surgery, while the volume of ABBW was similar in both groups. At T5, the bone resorption percentages of ACBW, ABBW, and ABH were 25.57%, 16.85% and 43.84% in IPS, and 33.55%, 15.92% and 46.44% in NIPS. A more rapid loss of alveolar crest in NIPS resulted from implant placement surgery, and this reminded us of the importance of immediate implant placement.

Study of the bones tissue reparation using nanostructured titanium implants with hydroxylapatite coatings by scanning electron microscopy

A method of medical implants (biocomposites) preparation based on nanostructured titanium with nanocrystalline bioactive hydroxylapatite coatings is developed. The operative treatment using these implants improves the regeneration of bone tissue for rats, as compared to the “false-operated” animals. The morphological data at 7, 14, 21, 45 days are obtained by means of scanning electron microscopy and discussed.

Comparison of Success Rate and Radiological Bone Loss in Patients with Mini-Implant versus Conventional-Sized Implant Removable Prostheses: A Meta-Analysis

Background: The objective of this meta-analysis was to assess whether mini-implants have added benefit in terms of implants success rate and average bone loss over conventional-sized implants after one year of follow-up. Methods: An electronic search of randomized clinical trials was conducted in MEDLINE (via PubMed), Cochrane Central Register of Clinical Trials (CENTRAL) and Web of Science for studies including complete or partial edentulous patients requiring two or four mini-implants or conventional/ standard-sized implants in the maxilla or mandible for implant-supported removable prostheses who completed 12 months of follow-up. Results: The search provided 194 unique articles which were screened for title and abstract. Screening generated 12 articles which went through full-text analysis using eligibility criteria, and 4 articles were included for meta-analysis. Meta-analysis of these studies indicated a non-significant difference in the success rate between the two interventions (OR = 1.69 [0.74, 3.85;p = 0.21]). Bone loss estimates resulted in a significant bone reduction (Mean Difference = -0.74 [-0.95, -0.53;p < 0.05]) in favor of two mini-implants when compared with two conventional-sized implants, but when compared four mini- with two conventional-sized implants, the estimates were non-significant (Mean Difference = -0.24 [-0.69, 0.20;p = 0.29]). Conclusion: The current evidence does not provide solid evidence of the benefits of one intervention over the other. More studies with follow-up times of 10 and more years are needed as current studies have described the short-term outcomes.

Simultaneous Upper and Lower Jaw Extractions, Autogenous Bone Augmentation and Temporary Implant Placement with Immediate Loading

Aims: We expanded the known technique for simultaneously augmenting an atrophic maxilla and placement of immediate provisional implants (IPI), followed by immediate loading by performing surgery in both jaws simultaneously. Feasibility of this new technique, implant survival and success were evaluated as well as prosthetic success. Materials and Methods: All patients undergoing simultaneous bone grafting and IPI placement with immediate loading at our institute between the 1st of June 2016 and the 30th of May 2018 were included and followed up for at least one year postoperatively. Results: 3 patients were followed for a mean period of 25.67 months (20 - 29 months). 33 IPIs were placed. All were immobile at second stage surgery without signs of infection. No provisional bridges were lost and no infections were noted. After second stage surgery, none of these 36 final dental implants were lost. There was some bone loss at one implant. In all patients, good functional and aesthetic results were obtained without any unforeseen complications. This renders the implant survival at 100% and the success rate at 97%. Conclusion: The technique is complex due to the intricate step-by-step process that is required and depends on a dedicated team to ensure a proper workflow. When performed correctly, the protocol shows good and predictable results.

The role of exosomes in bone remodeling and osseointegration of implants

Dental implant is an effective method in the treatment of missing teeth.The process of osseointegration of implant teeth involves the coordinated operation of immune system and bone system.The interaction between cells is closely related to bone formation and repair.Exosomes are important intercellular communication molecules.They were originally found in the supernatant of sheep erythrocytes cultured in vitro.They are micro vesicles with a diameter of 40~150 nm.They exist in a variety of cells and body fluids.They enter the target cells by endocytosis and transport,affecting the expression of cell genes and changing the fate of cells.It has an important regulatory function in the microenvironment of implant bone binding.It plays a role in bone remodeling through small molecular RNA,specific proteins and other growth factors secreted by different cells.This article reviews the role of bone derived cellderived exosomes in bone remodeling and their function in implant osseointegration.

A Case Report of Immediate Implant Placement Combined with Flap Surgery,Guided Bone Regeneration and Non-submerged Healing with a Labial Bone Wall Defect in the Esthetic Zone

[Basckground]This case report presented a methodology for immediate implantation in the esthetic zone with a facial bone defect along with flap surgery,guided bone regeneration,and non-submerged healing.[Case presentation]A 27-year-old female patient was complaining of the aesthetic complication that was caused via metallic staining of the neck of ceramic crowns in the maxillary right anterior region for one year.She has experienced immediate implantation along with flap surgery,guided bone regeneration(GBR),and non-submerged healing.The torque of the implant reached to the 35 N·cm to confirm primary stability.Six months after surgery,the healing abutment and the implant were fixed,the gingiva was healthy in the surgical area,and the nearby teeth and the opposite teeth were normal.[Results]The results of cone-beam computer tomography(CBCT)revealed that bone defects were filled with the newly formed bone.At the same time,the final impressions accomplished,and an all-ceramic crown was fit-placed.As a whole,the patient satisfaction rate was high.[Conclusions]Immediate implant placement with flap surgery,GBR,and non-submerged healing with a facial bone wall defect in the esthetic zone is an achievable process.