Peri-implant Tissue Research Articles

The effects of direct polymethylmethacrylate and zirconia-on-Ti-base abutments on peri-implant soft tissue integration: A study in minipigs.

To assess two types of abutment materials routinely used in daily prac-tice-direct polymethyl methacrylate (PMMA) and a zirconia-on-Ti-base abut-ment-and their effects on peri-implant soft tissues and bone remodeling in a mini-pig model. A total of 40 implants were placed in five mini-pigs in a single-stage surgery. Four different types of abutment materials (n = 10 per group) were used: (1) titanium (control); (2) zirconia (control); (3) PMMA (test 1); and (4) Ti-base (zirconia bonded to a titanium framework; test 2). After 3 months of healing, the samples were collected and subjected to nondecalcified histology. The soft tissue dimensions (sulcus, junctional epithelium, and connective tissue attach-ment) were assessed on each abutment mesially and distally, and the distance from the implant margin to the first bone-to-implant contact (BIC) was measured. No statistically significant differences were found among the four groups regarding soft tissue dimensions (P = .21), and a long junctional epithelium (mean: 4.1 mm) and a short connective tissue attachment (mean: 0.3 mm) were found in the majority of abutments. In some samples, the junctional epithelium extended all the way to the bone level. The measured peri-implant bone remodeling was similar in all four groups (P = .25). The present findings indicate that both di-rect PMMA and zirconia-on-Ti-base abutments seem to allow soft tissue integration similar to that of titanium and zirconia abutments. However, clinical studies are war-ranted to either confirm or refute the observed findings and to further investigate the influence of different materials on mucointegration.

Cobalt and Chromium Ions Impair Macrophage Response to Staphylococcus aureus Infection.

Cobalt-chromium-molybdenum (CoCrMo) alloys are routinely used in arthroplasty. CoCrMo wear particles and ions derived from arthroplasty implants lead to macrophage-driven adverse local tissue reactions, which have been linked to an increased risk of periprosthetic joint infection after revision arthroplasty. While metal-induced cytotoxicity is well characterized in human macrophages, direct effects on their functionality have remained elusive. Synchrotron radiation X-ray microtomography and X-ray fluorescence mapping indicated that peri-implant tissues harvested during aseptic revision of different arthroplasty implants are exposed to Co and Cr in situ. Confocal laser scanning microscopy revealed that macrophage influx is predominant in patient tissue. While in vitro exposure to Cr3+ had only minor effects on monocytes/macrophage phenotype, pathologic concentrations of Co2+ significantly impaired both, monocyte/macrophage phenotype and functionality. High concentrations of Co2+ led to a shift in macrophage subsets and loss of surface markers, including CD14 and CD16. Both Co2+ and Cr3+ impaired macrophage responses to Staphylococcus aureus infection, and particularly, Co2+-exposed macrophages showed decreased phagocytic activity. These findings demonstrate the immunosuppressive effects of locally elevated metal ions on the innate immune response and support further investigations, including studies exploring whether Co2+ and Cr3+ or CoCrMo alloys per se expose the patients to a higher risk of infections post-revision arthroplasty.

Major approaches to dental implants in the biological environment of bone regeneration: a systematic review

Introduction: The presence of sufficient bone volume, both in width and height, is crucial for adequate implant placement and osseointegration, allowing stability of the peri-implant hard and soft tissues. Several bone augmentation techniques can be performed to preserve or reconstruct a resorbed alveolar ridge or pneumatized maxillary sinus. Bone remodeling of the ridge and buccal bone will still occur after tooth removal. Objective: It was to develop a systematic review to present the main approaches to dental implants in the biological environment of bone regeneration. Methods: The present study was followed by a systematic review model (PRISMA). The search strategy was performed in the PubMed, Cochrane Library, Web of Science Scopus, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 123 articles were found involving implantology and biomaterials. A total of 48 articles were fully evaluated and 34 were included in the systematic review. A total of 26 studies were excluded because they did not meet the GRADE criteria, and 22 studies were excluded because they had a high risk of bias. The symmetric funnel plot does not suggest a risk of bias between the small sample size studies. It was concluded that the search for a solution for large bone defects guided studies toward tissue regeneration therapy or bone regeneration. These studies can promote the use of fillers and epithelial barriers that assist in treatment as adjuvants to bone grafting techniques. Understanding host biological niche processes of signaling for neovascularization and bone regeneration and filling is necessary for subsequent dental success. Furthermore, implants placed in tobacco users, as well as in enlarged maxillary sinuses, simultaneously or in stages, and enlarged ridges lead to higher rates of implant failure.

Single-cell sequencing identifies inflammation-promoting fibroblast-neutrophil interaction in peri-implantitis.

To reveal the cellular composition and molecular environment of the periodontal and peri-implant inflammatory infiltrates through a single-cell sequencing technique, which may explain the pathological difference between these two diseases. A special focus was placed on the phenotypes and potential roles of neutrophils and fibroblasts in peri-implant/periodontal tissue immunity. High-throughput single-cell transcriptomic profiling of peri-implant tissues from patients with peri-implantitis as well as periodontal tissues from patients with periodontitis and healthy donors was performed. Immunofluorescence analysis was carried out to further validate the identified cell subtypes and their involvement in peri-implantitis and periodontitis. Based on our single-cell resolution analysis, a quantified proportional increase of neutrophil (Neu) subtypes was shown in peri-implantitis. Among these, a predominance of Neutro_CXCR2 was revealed. We also found the involvement of inflammation-promoting fibroblasts as well as a predominance of CXCL8+ fibroblast-CXCR2+ neutrophil interaction in peri-implantitis. Our study indicated that the predominance of CXCL8+ fibroblast-CXCR2+ neutrophil interaction might underline the enhanced host response in peri-implantitis compared with periodontitis. This information offers a molecular basis by which fibroblast and neutrophil subtypes might be diagnostically and therapeutically targeted in peri-implantitis.

Isolation of TiNbN wear particles from a coated metal-on-metal bearing: Morphological characterization and in vitro evaluation of cytotoxicity in human osteoblasts.

To improve the wear resistance of articulating metallic joint endoprostheses, the surfaces can be coated with titanium niobium nitride (TiNbN). Under poor tribological conditions or malalignment, wear can occur on these implant surfaces in situ. This study investigated the biological response of human osteoblasts to wear particles generated from TiNbN-coated hip implants. Abrasive particles were generated in a hip simulator according to ISO 14242-1/-2 and extracted with Proteinase K. Particle characteristics were evaluated by electron microscopy and energy dispersive x-ray spectroscopy (EDS), inductively coupled plasma mass spectrometry (ICP-MS) and dynamic light scattering (DLS) measurements. Human osteoblasts were exposed to different particle dilutions (1:20, 1:50, and 1:100), and cell viability and gene expression levels of osteogenic markers and inflammatory mediators were analyzed after 4 and 7 days. Using ICP-MS, EDS, and DLS measurements, ~70% of the particles were identified as TiNbN, ranging from 39 to 94 nm. The particles exhibited a flat and subangular morphology. Exposure to particles did not influence cell viability and osteoblastic differentiation capacity. Protein levels of collagen type 1, osteoprotegerin, and receptor activator of nuclear factor κB ligand were almost unaffected. Moreover, the pro-inflammatory response via interleukins 6 and 8 was minor induced after particle contact. A high number of TiNbN wear particles only slightly affected osteoblasts' differentiation ability and inflammatory response compared to metallic particles. Nevertheless, further studies should investigate the role of these particles in peri-implant bone tissue, especially concerning other cell types.

Cytotoxicity of dental cement on soft tissue associated with dental implants at different time intervals.

To investigate and compare the effect of four commercially used dental cement at 24 hours, 48 hours,72 hours (h) and 6 days on the cellular response of human gingival fibroblast (HGF). 3 cement pellet samples were made for each 4-test cement (n=12). The cement used for this study were zinc phosphate (ZP), zinc oxide non-eugenol (ZOE), RelyX U200 (RU200), and glass ionomer cement (GIC). The cytotoxicity of peri-implant tissues was investigated using one commercial cell line. All processing was done following International Organization for Standardization (ISO) methods 10993-5 and 10993-12 (MTT assay Test). Cell cultures without dental cement were considered as control. Standard laboratory procedures were followed to permit cell growth and confluence over 48 hrs after sub-cultivation. Before being subjected to analysis, the cells were kept in direct contact with the cement samples for the suggested time period. To validate the results the specimens were tested three times each. Cell death and inhibition of cell growth were measured quantitatively. Results were analyzed using 1-way ANOVA (a=0.05) followed by Tukey B post hoc test. The study showed the dental cement test material was cytotoxic. ZOE, ZP, GIC, and RU200 were cytotoxic in decreasing order, respectively, significantly reducing cell viability after exposure to HGF (p <0.001). Within the limitations of this in-vitro cellular study, results indicated that HGF were vulnerable to the test the dental cement. The highest cytotoxicity was observed in ZOE, followed by ZP, GIC, and RU200.

A comparative study to evaluate microstrain of low-profile attachment associated with and without bar connection in implant assisted mandibular overdenture (in vitro study)

BackgroundThe aim of this study was to compare the microstrain transmitted to peri-implant tissues of implant-assisted mandibular overdentures using two different low-profile attachment designs; OT- Equator attachment with and without bar attachment.Materials and methodsA completely edentulous epoxy resin mandibular model was used, in which two parallel dental implants were inserted at the canine region bilaterally and one in the middle. Sixteen identical complete edentulous mandibular overdentures were fabricated following conventional, standardized techniques and were divided equally between two groups according to the design and placement of the OT-Equator. Group A implants were kept solitary with an OT-Equator attachment, while group B implants were kept splinted with a bar associated with two mini-OT-Equator attachments in between. Sixteen identical mandibular complete overdentures were constructed, to which attachments were picked up. The difference in stress distribution was measured using strain gauges and compared between the two studied groups. A vertical load of 100 N using the universal testing machine was applied unilaterally on the left mesial fossae of the mandibular first molar and bilaterally on the bar attached to the mandibular premolar molar region of the overdentures. Statistical analysis was conducted using IBM SPSS version 28. Normality was checked by using the Shapiro-Wilk test and normality plots. The Mann-Whitney U test was then used to analogize the groups.ResultsThere was a statistically significant difference between groups A and B upon application of vertical unilateral and bilateral loadings of 100 N, with mean microstrain values of P 0.05. Group A (OT-Equator attachment) showed lower strain values than Group B (OT-Equator bar attachment) upon application of vertical, unilateral, and bilateral loadings of 100 N.ConclusionsImplant-assisted mandibular overdenture with a solitary attachment is associated with lower microstrain values around the implants after application of unilateral and bilateral vertical loadings of 100 N.

Platelet-rich fibrin stimulates the proliferation and expression of proteins related to survival, adhesion, and angiogenesis in gingival fibroblasts cultured on a titanium nano-hydroxyapatite-treated surface

ObjectivesThis in vitro study aimed to evaluate the cell viability and expression of proteins related to angiogenesis, adhesion, and cell survival (vascular endothelial growth factor, paxillin, vinculin, fibronectin, and protein kinase B) in gingival fibroblasts that were cultured on titanium discs treated with or without nanohydroxyapatite and exposed to platelet-rich fibrin (PRF)-conditioned medium. MethodsTo obtain the conditioned medium, the PRF membranes were prepared and incubated for 48 h in a culture medium without fetal bovine serum. Analyses were performed at 24 and 48 h for the cells cultured on machined-titanium discs or surfaces treated with nanohydroxyapatite in a control medium or PRF-conditioned medium, resulting in four experimental groups (CT-TI, CT-NANO, PRF-TI, and PRF-NANO). ResultsA decrease in the viability of the gingival fibroblasts was not observed in any of the experimental groups. The PRF-NANO group showed significantly higher immunoexpression of paxillin and AKT at 24 and 48 h (p < 0.01). The same result was observed for vinculin expression at 24 h (p < 0.001). The expression of fibronectin at 48 h and VEGF at 24 and 48 h was significantly higher when the cells were exposed to the PRF-conditioned medium, regardless of the disc surface (p < 0.05). ConclusionGingival fibroblasts cultured on a nanohydroxyapatite-treated surface and in a PRF-conditioned medium showed a greater expression of proteins modulating adhesion, angiogenesis, and cell survival. Our results may contribute to the understanding of the mechanisms related to peri-implant soft tissue sealing.

A two-year prospective study to compare the peri-implant parameters of posterior implant-supported single crowns with and without mesial proximal contact loss

Background/purposeInterproximal contact loss may lead to food impaction and result in subsequently periodontal complications. The purpose of this prospective study was to investigate the peri-implant parameters of posterior implant-supported single crowns (SCs) with and without mesial proximal contact loss after 2 years of follow-up. Material and methodsTwenty-six patients with a total of 40 posterior implant-supported SCs with mesial adjacent natural teeth were observed for 24 months after crown insertion. The mesial proximal contacts were assessed by dental floss, then were classified as tight, weak, and open contacts. The following peri-implant parameters were evaluated, including modified plaque index (MPI), modified gingival index (MGI), and probing depth (PD) were conducted at six sites per tooth (mesiofacail, midfacial, distofacial, mesiolingual, mid-lingual and distolingual) in the 6-, 12-, 18- and 24-month following visits. Furthermore, radiographs were taken regularly in 12- and 24-month recall sections for measuring the marginal bone loss (MBL). ResultsAt 12-month observation, the incidence rates of weak and open contacts were 22.5 % and 12.5 %; whereas after 24 months of clinical service, the rates came up with 12.9 % and 25.6 %, respectively. No significant differences were found between the tight, weak, and open contact groups in the parameters of MPI, MGI, or PD (P > 0.05) at 12- and 24-month follow-up. None of the mean differences of the peri-implant parameters: MPI, MGI, PD and MBL had significant differences between the tight, weak, and open contact groups after 1 and 2 years of clinical service (P > 0.05). ConclusionThe presence of open, weak, and tight mesial proximal contacts had no significant effects on the peri-implant tissue conditions.

The Effect of Plasma Spray Treated Healing Abutment on Peri-Implant Soft Tissue: A Case Report

The Effect of Plasma Spray Treated Healing Abutment on Peri-Implant Soft Tissue: A Case Report

A digital technique for cloning the emergence profile of the interim to the definitive implant-supported restoration

The subgingival contour of implant-supported restorations is key to ensuring the long-term health of the peri-implant bone and soft tissues. This report describes a step-by-step technique used to accurately clone the emergence profile of the interim crown for the definitive implant-supported restoration.

Esthetic reconstruction of a localized severely resorbed anterior maxilla associated with peri-implantitis: A clinical report

This clinical report described the esthetic reconstruction of a localized severely resorbed right anterior maxilla associated with peri-implantitis. For vertical bone augmentation, guided bone regeneration surgery was performed by raising a flap with the remote incision technique, followed by soft tissue grafting and vestibuloplasty. The biologically oriented preparation technique was used to improve the health and stability of the peri-implant tissues. The surgical treatment and a novel method of prosthetic rehabilitation provided excellent esthetic and functional outcomes.

Peri-implant health after microvascular head and neck reconstruction-A retrospective analysis.

Prosthodontic rehabilitation after reconstruction with microvascular revascularized free flaps following ablative tumor surgery is challenging due to the altered anatomical and functional conditions. The aim of this retrospective study was to determine whether the type of graft and the type of peri-implant tissue have an effect on peri-implant inflammatory parameters and implant survival. Patients who received a free flap reconstruction with subsequent implant-prosthetic rehabilitation between 2010 and 2022 were retrospectively included. The primary outcome variable was the probing depth (PPD) at a minimum of 1 year after completion of prosthetic restoration. Predictive variables were type of free flap, emergence profile, and history of radiation. Seventy-one patients after free flap reconstruction were included in the analysis. At a minimum of 24 months after implant insertion the primary outcome, PPD showed no clinically relevant differences between the types of free flaps used. The emergence profile through a skin island resulted in an increase in BOP compared to native mucosa in the descriptive analysis (p-value > .05). The analysis showed a 5-year implant survival of 96.2% (95% CI: 0.929-0.996) in cases without irradiation and 87.6% (95% CI: 0.810-0.948) with irradiation of the region evaluated (p-value .034). Flap and associated soft tissue type had no significant effect on 5-year implant survival or peri-implant inflammatory parameters. However, the large heterogeneity of the patient population indicates that further prolonged studies are required for a more differentiated assessment of the long-term success.

Evaluation of implants in smoking and non-smoking patients with peri-implant disease risk analysis and esthetic scores: an observational study

BackgroundThis study examined how smoking affects esthetics, peri-implant health, gingiva around the implant, and implant disease risk assessment in patients with implants.MethodsThe study included two hundred ninety-eight implants of systemically healthy patients aged between 38 and 62 who applied to the Periodontology Clinic and whose functionally prosthesis-loaded implants had been at least six months and at most five years old. Implants of patients with bruxism were not included in the study. Implants are divided into two according to the patient’s smoking. Vestibule depth around the implant, keratinized gingival thickness and width, gingival recession, bleeding on probing, pocket depth, and gingival index by a sole clinician. The pink esthetic score, peri-implant disease risk assessment, and implant health scale were also examined to measure implant esthetics and success.ResultsThere was a statistically significant difference in the implant disease risk assesment scores for the examined implants of smokers and nonsmokers (p < 0.05). People who had peri-implantitis had higher implant disease risk assesment score levels. The dental implant health scale revealed a statistically significant difference (p < 0.05) in the likelihood of implant disease. According to the dental implant health scale, dental implants were 100% successful for non-smokers. There was a significant difference in the keratinized gingiva width between smokers and nonsmokers (p < 0.05). The results of the study showed that nonsmokers had a wider keratinized gingiva.ConclusionsResearch has demonstrated that the act of smoking has the potential to jeopardize the long-term survival of dental implants and the surrounding peri-implant tissues. The results of this study indicate that it would be advisable for dentists to provide guidance to their patients on smoking cessation and to monitor any alterations in behavior closely. Furthermore, it would be advantageous for dental professionals to elucidate the impact of smoking on the susceptibility of smokers to peri-implant disease.

Heterogeneity of outcomes in randomized controlled trials on implant prosthodontic therapy is hindering comparative effectiveness research: meta-research study

BackgroundConsistency in outcomes across clinical trials allows for comparing and combining results from different studies. A core outcome set (COS), representing a minimally agreed standardized group of outcomes that should be monitored and measured through research in a specific field of medicine, is not yet available for trials in implant prosthodontic (dental implant) therapy. This meta-research study aimed to analyze outcomes used in clinical trials on implant prosthodontic therapy.MethodsWe searched the Cochrane Oral Health Group (COHG) register to identify systematic reviews of interventions in implant prosthodontic therapy published by October 2023. From the randomized controlled trials (RCTs) included in the relevant reviews, we extracted data on the characteristics of the included trials and the outcomes used. We categorized outcomes into domains.ResultsFrom 182 systematic reviews in the COHG register, we included 11 systematic reviews on dental implant therapy. The reviews included 117 unique RCTs with 4725 participants, published from 1995 to 2020, which analyzed 74 different outcomes. Using different definitions, implant failure was analyzed in 73 RCTs. Seventeen RCTs did not define implant failure. Failure was most often (30 RCTs) followed up for one year. Only one RCT assessed implant failure after five years. Trials used 17 definitions of implant failure, while 17 trials did not report on the criteria of implant failure. Complications were analyzed in 48 RCTs, although they were not clearly defined in 12 RCTs. Failure of prosthodontic supra-structure was analyzed in 74 RCTs, with definitions of failure and criteria not clearly defined in 44 RCTs. Trials considered adverse events, peri-implant tissue health, patient attitudes, and other outcomes, including cost, aesthetics, or procedure duration. These outcomes were often different between trials. Twenty-six outcomes were used only once per study.ConclusionsClinical trials in implant prosthodontics used different outcomes, different definitions of outcomes and used different times to monitor them. Standardization of outcomes is necessary to allow comparability and evidence synthesis about the effectiveness of implant prosthodontic therapy.

Conversion of the anatomic crown of a natural tooth to an interim-retained restoration for enhanced esthetics and soft tissue stability in the maxillary esthetic zone: A clinical report.

Immediate non-functional loading of an implant in the anterior region is a documented treatment modality with high success rates. This therapeutic approach is frequently used to overcome esthetic and functional problems during the provisionalization period, but also because it provides better support of the peri-implant soft tissues. For that purpose, an implant-supported resin restoration, either traditionally or digitally made, is used. This clinical report describes the modification of patient's natural tooth, that was previously fractured, used as an implant-supported provisional restoration to obtain better esthetics and preservation of the soft tissues in their original, pre-extraction, position.

Computer-guided miniscrew insertion in the paramedian and parapalatal area of the palatal vault: low failure rate and no learning curve required to obtain predictable results?

To evaluate the failure rate of palatal computer-guided miniscrews, placed in paramedian and parapalatal regions for orthodontic purposes. In addition, to investigate the presence of a learning curve using computer guided miniscrew insertion, and to evaluate the peri-implant soft tissues response at 2-, 6- and 12- month follow-ups. 202 palatal computer-guided miniscrews were inserted in 78 subjects for orthodontic purposes. A surgical guide was designed after planning the appropriate insertion sites on three-dimensional images created by the fusion of cone-beam computed tomography (CBCT) and digital dental model images. The devices were disassembled monthly to perform the percussion test and to evaluate the mobility of each miniscrew. To determine the presence of a learning curve, the time of miniscrew failures and the number of surgeries were evaluated. Bleeding on probing (BOP) and probing pocket depth (PPD) were recorded for each miniscrew, at 2- (T0), 6- (T1), and 12-month follow ups (T2). An immediate failure rate of 4.95%, due to lack of primary stability immediately following miniscrew insertion, was recorded, with statistically significant higher failure rate of parapalatal miniscrews (P&#61; 0.00). Miniscrew failure occurred at random time, with an absence of a learning curve. The BOP (mean: 3.13%) and PPD (mean: 1.68mm) measurements remained stable over time. Computer-guided miniscrew insertion in the palatal vault showed a low failure rate without a determined learning curve to obtain predictable results and with long-term stability of peri-implant soft tissues indexes.

AETIOLOGICAL CHARACTERISTICS OF DENTAL IMPLANT FAILURE

Dental implant placement is a predictable and widely used procedure in modern dentistry. Nevertheless, several factors can negatively affect the functioning and duration of implant restoration. Considering the significant data supporting the role of the microbial factor in the development of tissue inflammation around the prosthesis, the purpose of this review was to investigate the etiological structure of implant loss from a microbiological point of view. Materials and methods. We conducted a comprehensive content analysis of scientific publications available in the PubMed/MEDLINE and Google Scholar databases. Results and discussion. Six groups of microorganisms are known as potential contributor to the dental biofilm. These groups are designated by a specific color – yellow, green, purple, orange and red. The orange and red groups include pathogens of periodontal inflammation, and also play a significant role in the development of peri-implant (PI) inflammation. Implants and teeth share histopathological and ecological similarities, thus, we can suggest that the microbial communities around these structures are similar. In the studies, the composition of the PI-associated complex of microorganisms including Porphyromonas gingivalis, Porphyromonas endodontalis, Tannerella forsythia, Filifactor alocis, Fretibacterium fastidiosum, Desulfobulbus spp. and Treponema lecithinolyticum was decsribed. It has been reported that the PI microbiome is specific to the site where an implant is placed, and the microbial composition of the biofilm of the contralateral healthy sites is more similar to the spectrum of healthy prostheses, including other subjects, than those from the same oral cavity. We can suggest that the changes in the implant microbiocenosis are dynamic. Several studies have shown the long-term consequences of dental implant restoration that can include the modification of the microbiome consisting in the progressive increase of P. gingivalis, T. forsythia, A. actinomycetemcomitans and Prevotella intermedia within 3-6 months following the procedure of implant placement. There is also an opinion about the peculiarities of the biofilm microbiota of the peri-implant tissues in case of early and late loss of the dental prosthesis. Bacteria are an important component of the microbiocenosis in any ecological niche, but the role of archaea is often overlooked. Methanogenic archaea, and Methanobrevibacter oralis are components of the normal oral microbiome, but their considerable prevalence may also be associated with peri-implant tissue inflammation. Conclusions. We have elucidated the complex nature of microbial communities within peri-implant sites and established an association between peri-implant diseases and the dysbiosis of subgingival microbial communities. Our study underscores the pivotal role of microbiota in peri-implant diseases.

EXPERIENCE IN APPLYING OSTEOPLASTIC MATERIALS CONTAINING MULTIPOTENT MESENCHYMAL STROMAL CELLS AND HYDROXYAPATITE IN PATIENTS BEFORE THE PROCEDURE OF DENTAL IMPLANT PLACEMENT

Introduction of modern osteoplastic material into practical work is extremely important for effective filling of bone defects, restoration of lost periodontal tissue, relief of postoperative symptoms and reduction of inpatient treatment of patients after surgery. Up-to-date materials will improve regenerative and reparative properties of the bone tissue and promote its increasing volume for further successful dental implantation. Objective of the research was to determine an application effect of osteoplastic materials based on multipotent mesenchymal stromal cells of the adipose tissue and hydroxyapatite used for filling bone defects during dental surgery in patients, before dental implantation. Materials and methods. 140 patients were examined and treated by means of dental implantation. Before implantation, in order to increase the volume of the bone tissue of the cellular processes and cellular part of the corresponding jaw, various osteoplastic materials were applied during surgery. All the patients were distributed into III groups: І included 49 individuals (35,0 %), II group – 62 patients (44,29 %), and III (control) group included 29 patients (20,71 %). In I group a bone tissue substitute based on hydroxyapatite was used to restore the bone tissue of the cellular processes and the cellular pert of the corresponding jaw. In II group augmentation of bone defects was carried out by means of the suggested composition consisting of multipotent mesenchymal stromal cells of the adipose tissue, platelet-rich blood plasma and bone tissue substitute based on hydroxyapatite. In ІІІ group, the wound healed spontaneously under a blood clot. Results. After installation of dental implants, the peri-implant tissues were found to restore completely in cases where the combination of multipotent mesenchymal stromal cells of the adipose tissue, a bone substitute based on hydroxyapatite, and platelet-rich blood plasma was used for filling bone defects. Moreover, according to X-ray findings obtained 12 months later, in patients from II group the volume of the bone tissue resorption in the areas of implantation was 1,4 and 1,8 times lower than in individuals from І group, р1&lt;0,01, and ІІІ control group, р2&lt;0,01, respectively. Conclusions. The effectiveness of application of osteoplastic materials based on multipotent mesenchymal stromal cells of the adipose tissue and hydroxyapatite is confirmed by the values of the stability coefficient of implants. After 12 months of the research, these values were reliably higher than those of the reference, р&lt;0,01. They were 12,43 % and 19,33 % higher than in patients from І main group and ІІІ control group.

Effect of customized abutment taper configuration on bone remodeling and peri-implant tissue around implant-supported single crown: A 3D nonlinear finite element study.

The optimal configuration of a customized implant abutment plays a crucial role in promoting bone remodeling and maintaining the peri-implant gingival contour. However, the biomechanical effects of abutment configuration on bone remodeling and peri-implant tissue remain unclear. This study aimed to evaluate the influence of abutment taper configurations on bone remodeling and peri-implant tissue. Five models with different abutment taper configurations (10°, 20°, 30°, 40°, and 50°) were analyzed using finite element analysis (FEA) to evaluate the biomechanical responses in peri-implant bone and the hydrostatic pressure in peri-implant tissue. The results demonstrated that the rate of increase in bone density was similar in all models. On the other hand, the hydrostatic pressure in peri-implant gingiva revealed significantly different results. Model 10° showed the highest maximum and volume-averaged hydrostatic pressures (69.31 and 4.5mmHg), whereas Model 30° demonstrated the lowest values (57.83 and 3.88mmHg) with the lowest excessive pressure area. The area of excessive hydrostatic pressure decreased in all models as the degree of abutment taper increased from 10° to 30°. In contrast, Models 40° and 50° exhibited greater hydrostatic pressure concentration at the cervical region. In conclusion, the abutment taper configuration had a slight effect on bone remodeling but exerted a significant effect on the peri-implant gingiva above the implant platform via hydrostatic pressure. Significant decreases in greatest and average hydrostatic pressures were observed in the peri-implant tissues of Model 30°. However, the results indicate that implant abutment tapering wider than 40° could result in a larger area of excessive hydrostatic pressure in peri-implant tissue, which could induce gingival recession.