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Martina Trentini,1,* Ugo D’Amora,2,* Alfredo Ronca,2 Luca Lovatti,2 José Luis Calvo-Guirado,3 Danilo Licastro,4 Simeone Dal Monego,4 Lucia Gemma Delogu,5 Mariusz R Wieckowski,6 Shlomo Barak,7 Oleg Dolkart,7 Barbara Zavan1 1Translational Medicine Department, University of Ferrara, Ferrara, 44121, Italy; 2Institute of Polymers, Composites and Biomaterials - National Research Council (IPCB-CNR), Naples, 80125, Italy; 3Faculty of Health Sciences, Universidad Autonoma de Chile, Santiago de Chile, 7500912, Chile; 4AREA Science Park, Trieste, 34149, Italy; 5Biomedical Science Department University of Padova, Padova, Italy; 6Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland; 7Magdent B.S.R. 3, Bnei Brak, Tel Aviv, Israel*These authors contributed equally to this workCorrespondence: Alfredo Ronca; Barbara Zavan, Email alfredo.ronca@cnr.it; barbara.zavan@unife.itIntroduction: In the process of bone regeneration, a prominent role is played by macrophages involved in both the initial inflammation and the regeneration/vascularization phases, due to their M2 anti-inflammatory phenotype. Together with osteoclasts, they participate in the degradation of the bone matrix if the inflammatory process does not end. In this complex scenario, recently, much attention has been paid to extracellular communication mediated by nanometer-sized vesicles, with high information content, called exosomes (EVs). Considering these considerations, the purpose of the present work is to demonstrate how the presence of a pulsed electromagnetic field (PEMF) can positively affect communication through EVs.Methods: To this aim, macrophages and osteoclasts were treated in vitro with PEMF and analyzed through molecular biology analysis and by electron microscopy. Moreover, EVs produced by macrophages were characterized and used to verify their activity onto osteoclasts.Results: The results confirmed that PEMF not only reduces the inflammatory activity of macrophages and the degradative activity of osteoclasts but that the EVS produced by macrophages, obtained from PEMF treatment, positively affect osteoclasts by reducing their activity.Discussion: The co-treatment of PEMF with M2 macrophage-derived EVs (M2-EVs) decreased osteoclastogenesis to a greater degree than separate treatments. Keywords: PEMF, exosomes, macrophages, bone, osteoclast

The elbow is one of the most commonly dislocated joints. Although simple dislocations of the elbow usually resolve with conservative management, certain patients can experience residual chronic instability. Posterolateral rotational instability accounts for approximately 80% of elbow chronic instability cases. We propose an all-arthroscopic reconstruction of the posterior, or ulnar, fascicle of the lateral ligament complex using an autograft or allograft, performed with a 5-mm-thick and 8-cm-long graft. The graft is first inserted distally into the supinator crest with an Arthrex 4.75-mm SwiveLock implant and, finally, at its origin in the epicondyle, also with a screw of the same characteristics. Arthroscopic techniques create fewer complications. This procedure allows the surgeon to address intra-articular elbow joint pathology with less chance of wound complications and the ability to use bone anchors if desired., Competing Interests: All authors (F.M.M., C.M.G., A.G.L., M.V.A., J.L.C-G., C.S.P.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

This study aimed to assess the bone regeneration of critical-size defects in rabbit calvaria filled with freshly crushed extracted teeth, comparing them with BTCP biomaterial and empty sites. Materials and methods: Twenty-one female New Zealand rabbits were used in this study. Two critical-size defects 6 mm in size were created in the skull bone, each with a 3 mm separation between them. Three experimental groups were evaluated: Group A (human sterilized crushed teeth granules alone), Group B (Bioner Bone, Bioner Sitemas Implantológicos), and Group C (unfilled defects). The animals were sacrificed at 4 and 8 weeks. Evaluation of the samples involved histological and histomorphometric analyses with radiographic evaluation. The histological evaluation showed a higher volume reduction in Group A compared with Group B ( p < 0.05) and Control. Group A showed the highest values for cortical closure and bone formation around the particles, followed by Group B and Group C ( p < 0.05). Within the limitations of this animal study, we can conclude that the use of human tooth particles leads to increased bone formation and reduced connective tissue in critical-size defects in rabbit calvaria when compared to BTCP biomaterial. The calvarial model is a robust base for the evaluation of different biomaterials.

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is the most common developmental defect that significantly affects the morphology and function of the stomatognathic system in children. The etiology of these birth defects is multifactorial, and single nucleotide polymorphisms (SNPs) in IRF6 and FGF1 have been associated with NSCL/P. This study aimed to evaluate whether SNPs in IRF6 , namely rs2013162, rs642961, rs2235373, and rs34010 in FGF1 , are associated with NSCL/P occurrence in the Polish population. The study included 627 participants: 209 children with NSCL/P and 418 healthy controls. DNA was isolated from saliva in the study group and from umbilical cord blood in controls. Genotyping of polymorphisms was performed using quantitative PCR. There was no statistically significant association of IRF6 gene variants with NSCL/P occurrence, although for rs2013162, AA genotype, odds ratio (OR) = 1.16 and for AC genotype, OR = 0.83; for rs642961, AA genotype, OR = 0.84 and for AG genotype, OR = 1.41; and for rs2235373, AA genotype, OR = 0.79 and for AG, OR = 0.85. In the instance of rs34010 polymorphism in FGF1 , the presence of the AA genotype was statistically significant in reducing the risk of NSCL/P (OR = 0.31, p = 0.001). Genetic variation in FGF1 is an important risk marker of NSCL/P in the Polish population, which cannot be stated for the polymorphisms in the IRF6 gene., Competing Interests: Conflict of interest: The authors declare no conflict of interest., (© 2023 the author(s), published by De Gruyter.)

Background and Objectives : The aim of this study is to evaluate the efficacy of an autologous dentin graft, via extracted teeth that are processed into bacteria-free particulate dentin in a Smart dentin grinder and then grafted immediately into alveolus post extraction or into bone deficiencies. Materials and Methods: Ten healthy, partially edentulous patients with some teeth in the mandible were recruited in the study. After their own teeth were grinded, particulate teeth were placed in empty sockets and bone defects after teeth extractions. Furthermore, after three, six, 12 and 24 months, core samples using a 3 mm trephine were obtained. Results: At three months, the particles of grinded tooth were immersed inside a new connective tissue with a small new bone formation (16.3 ± 1.98). At six months, we observed small particles of dentin integrated in new immature bone, without inflammation in the soft tissue (41.1 ± 0.76). At twelve months, we observed a high amount of bone formation surrounding tooth particles (54.5 ± 0.24), and at twenty-four months, new bone, a big structure of bone, was observed with dentin particles (59.4 ± 1.23), statistically different when compared it with at three months. Conclusions: A particulate dentin graft should be considered as an alternative material for sockets' preservation, split technique, and also for sinus lifting. One of the special characteristics after 24 months of evaluation was the high resorption rate and bone replacement without inflammation. This material could be considered as an acceptable biomaterial for different bone defects due to its osteoinductive and osteoconductive properties.

Aim: To observe clinically and radiographically (CBCT), the extent of bone resorption in extraction socket without the use of bone graft substitutes and delayed implant placement., Material and Methods: 50 compliant patients were selected for study. All the patients who were advised extraction were followed up for entire duration of the treatment, at 5th week CBCT showed horizontal and vertical bone loss. To prevent further bone resorption, after 5 weeks implant was placed along with bone graft., Results: Bone resorption after extraction is an unavoidable phenomenon. Clinical and radiographic (CBCT) analysis showed massive bone resorption by 5th week. At 5 month CBCT, all patients showed stable implant integration. There was no implant failure at the end of the study., Conclusion: Alveolar preservation is proven to slow down socket wall collapse with the use of a bone substitute material without which larger procedures maybe needed to restore alveolar integrity and harmony. Immediate implant placement is effective when bone graft is placed in the jumping distance., Competing Interests: None., (© 2020 Published by Elsevier B.V. on behalf of Craniofacial Research Foundation.)

Background and objectives: To evaluate whether sinus augmentation, using a minimally invasive implant device, via a non-submerged surgical approach, might negatively influence the outcome. Materials and Methods: A retrospective cohort study was conducted by evaluating patients' files, classifying them into two groups. Fifty patients (22 men 28 women) were included in the study, 25 in each group. The use of an implant device based on residual alveolar ridge height for sinus augmentation, radiographic evaluation, insertion torque, membrane perforation, post-operative healing, and a minimum of 12 months follow-up were evaluated. Results: The mean residual alveolar ridge height was 5.4 mm for the non-submerged group and 4.2 mm for the submerged group. There were no intraoperative or postoperative complications (including membrane perforations). The mean insertion torque was 45 N/cm for the study group and 20 N/cm for the control group. Complete soft tissue healing was observed within three weeks. Mean bone gain height was 8 mm for the study and 9.3 mm for the control group. All implants osseointegrated after 6-9 months of healing time. Mean follow-up was 17.5 months, range 12-36 months. Marginal bone loss at last follow-up was not statistically significantly different: 1 mm in the non-submerged vs. 1.2 mm in the submerged group. Conclusions: Submerged and non-submerged healing following maxillary sinus augmentation was comparable provided residual alveolar ridge height >5 mm and insertion torque >25 N/cm., Competing Interests: This study was not supported by a grant. Prof. Gavriel Chaushu is on the scientific advisory board for Maxillent LTD, Herzliya Israel and gave lectures sponsored by the company. Dr. Hadar Better is Co-founder, consultant and shareholder of Maxillent LTD, Herzliya Israel. Drs. Liat Chaushu, Sarit Naishlos , Juan Manuel Aragoneses, José Luis Calvo-Guirado and Prof. Joseph Nissan report no conflicts of interest related to this study.

In many clinical situations, rehabilitation with implants in the posterior maxillary region is complicated by limited bone availability. In this context, the use of 4 mm long implants (known as extra-short implants) may be used thanks to the concept of osseointegration enhancement. It has been demonstrated that short implants offer an alternative to the regeneration procedures involved in placing longer implants in areas where bone height is compromised. This prospective pilot study tested a treatment protocol in which 11 extra-short (4 mm) implants were splinted to 11 mesially placed longer (8 mm) implants in the posterior maxillary regions of partially edentulous patients, without using supplementary bone regeneration procedures. Eleven patients were included in this single cohort study. The clinical performance of the extra-short implants was assessed during a two-year follow-up period, obtaining a 100% survival rate and mean bone loss of 0.3 mm. Implant stability measured by resonance frequency analysis (RFA) at the time of placement was 54.9 ± 4.9, increasing to 77.0 ± 2.6 at 24 months. The study demonstrated the gradual consolidation of osseointegration in bone of less-than-ideal quality in the posterior maxillary region. The results obtained show that a partially edentulous maxilla with reduced bone height may be rehabilitated by using an extra-short implant splinted to a mesial implant of 8mm length or longer. Despite the small sample size, this pilot study observed that extra-short implants achieved adequate bone stability and clinical performance after a 24-month follow-up., Competing Interests: The authors declare no conflict of interest.

Calcium phosphate materials are widely used as bone substitutes due to their bioactive and biodegradable properties. Also, the presence of silicon in their composition seems to improve the bioactivity of the implant and promote bone tissue repair. The aim of this study was to develop a novel ceramic scaffold by partial solid-state sintering method with a composition lying in the field of the Nurse's A-phase-silicocarnotite, in the tricalcium phosphate-dicalcium silicate (TCP-C 2 S) binary system. Also, we evaluated its osteogenic and osteoconductive properties after being implanted into tibia defects in New Zealand rabbits. X-ray, microcomputer tomography, and histomorphometry studies demonstrated that this porous ceramic is highly biocompatible and it has excellent osteointegration. The material was being progressively reabsorbed throughout the study and there was no unspecified local or systemic inflammatory response observed. These results suggest that ceramic imitates the physicochemical characteristics of bone substitutes used in bone reconstruction.

Background: The aim of this study was to retrospectively analyze two different sealing techniques for sinus membrane perforations produced during sinus floor augmentation by a lateral approach., Methods: A total of 172 lateral-approach sinus floor augmentation surgeries were performed on 130 patients. Sixty-one membrane perforations (35%) were reported. Most of the perforations were caused by accidental membrane tearing and 16 (26%) were caused by deliberate incision for mucocele removal. In 31 perforation cases (51%), the Schneiderian membrane was sealed by suturing, while the remaining 30 cases (49%) were sealed using a low-resorption collagen membrane coverage., Results: Out of the 31 cases treated with a suture-sealing techniques, 26 (84%) were successful, presenting graft integration. Failure occurred in the other five (16%) cases. Out of the 30 perforations sealed with low-resorption collagen membranes, 28 (93%) presented successful graft integration, while two (7%) failed., Conclusions: Both surgical techniques yielded therapeutic success.

Closure of the surgical incision has been the primary function of sutures since their introduction. However, whatever the type, they are known to carry bacteria, which can be a source of infection. Five types of surgical sutures, Gut, Silk, Vicryl, PTFE, and Polyamide, were selected and tested on their ability to carry aerobic and anaerobic bacteria and were rated on the basis of forming colony-forming units (CFUs). Aerobic bacteria grown around gut sutures showed minimum CFUs (≈30 × 10 4 /suture). Though very less anaerobic bacteria growth was seen among all tested suture materials, it was maximum around Vicryl and polyamide sutures. Every suture material is capable, albeit not equally, of holding bacterial biofilm formation, which can be a source of surgical site infection.

Background: The goal of this study was to analyze the stress distribution on two types of extra-short dental implants with 5 mm of length: An internal hexagon (IH) and morse taper connection (MT)., Methods: The three-dimensional model was composed of trabecular and cortical bone, a crown, an extra-short dental implant and their components. An axial load of 150 N was applied and another inclined 30° with the same magnitude., Results: Stress concentrations on the IH implant are observed in the region of the first threads for the screw. However, in the MT implant the highest stress occurs at the edges of the upper implant platform., Conclusions: In view of the results obtained in this study the two types of prosthetic fittings present a good stress distribution. The Morse taper connections presented better behavior than the internal in both loading configurations., Competing Interests: The authors declare no conflict of interest.

This animal study evaluated the osseointegration level of a new nanotextured titanium surface produced by anodization. Ti-cp micro-implants (1.5 mm diameter by 2.5 mm in length) divided into two groups: titanium nanotextured surface treatment (Test Group) and acid etched surface treatment (Control Group). Surface characterization included morphology analysis using scanning electron microscopy and wettability by measuring contact angle. Sixteen Wistar rats were submitted to two micro implants surgical placement procedures. In each rat, one type of micro implant placed in each tibia. The animals sacrificed after two (T1) and six weeks (T2) post-implantation. After the euthanasia, tibias processed for histomorphometric analysis, which allowed the evaluation of bone to implant contact (BIC) and the bone area fraction occupancy between the threads (BAFO). Our surface analysis data showed that the Control Group exhibited an irregular and non-homogenous topography while the Test Group showed a nanotextured surface. The Test Group showed higher wettability (contact angle = 5.1 ± 0.7°) than the Control Group (contact angle = 75.5 ± 4.6°). Concerning the histomorphometric analysis results for T1, Control and Test groups showed BIC percentages of 41.3 ± 15.2% and 63.1 ± 8.7% ( p < 0.05), respectively, and for BAFO, 28.7 ± 13.7% and 54.8 ± 7.5%, respectively ( p < 0.05). For T2, the histomorphometric analysis for Control and Test groups showed BIC percentages of 51.2 ± 11.4% and 64.8 ± 7.4% ( p < 0.05), respectively and for BAFO, 36.4 ± 10.3% and 57.9 ± 9.3% ( p < 0.05), respectively. The findings of the current study confirmed that the novel nanotextured surface exhibited superior wettability, improved peri-implant bone formation, and expedited osseointegration., Competing Interests: The authors declare no conflict of interest.

Threads of dental implants with healing chamber configurations have become a target to improve osseointegration. This biomechanical and histometric study aimed to evaluate the influence of implant healing chamber configurations on the torque removal value (RTv), percentage of bone-to-implant contact (BIC%), bone fraction occupancy inside the thread area (BAFO%), and bone and osteocyte density (Ost) in the rabbit tibia after two months of healing. Titanium implants with three different thread configurations were evaluated: Group 1 (G1), with a conventional "v" thread-shaped implant design; Group 2 (G2), with square threads; and Group 3 (G3), the experimental group with longer threads (healing chamber). Ten rabbits (4.5 ± 0.5 kg) received three implants in each tibia (one per group), distributed in a randomized manner. After a period of two months, the tibia blocks (implants and the surrounding tissue) were removed and processed for ground sectioning to evaluate BIC%, BAFO%, and osteocyte density. The ANOVA one-way statistical test was used followed by the Bonferoni's multiple comparison test to determine individual difference among groups, considering a statistical difference when p < 0.05. Histometric evaluation showed a higher BAFO% values and Ost density for G3 in comparison with the other two groups (G1 and G2), with p < 0.05. However, the RTv and BIC% parameters were not significantly different between groups ( p > 0.05). The histological data suggest that the healing chambers in the implant macrogeometry can improve the bone reaction in comparison with the conventional thread design.

The aim of this experimental animal study was to assess guided bone regeneration (GBR) and implant stability (ISQ) around two dental implants with different macrogeometries. Forty eight dental implants were placed within six Beagle dogs. The implants were divided into two groups ( n = 24 per group): G1 group implants presented semi-conical macrogeometry, a low apical self-tapping portion, and an external hexagonal connection (whereby the cervical portion was bigger than the implant body). G2 group implants presented parallel walls macrogeometry, a strong apical self-tapping portion, and an external hexagonal connection (with the cervical portion parallel to the implant body). Buccal (mouth-related) defects of 2 mm (c2 condition) and 5 mm (c3 condition) were created. For the control condition with no defect (c1), implants were installed at crestal bone level. Eight implants in each group were installed under each condition. The implant stability quotient (ISQ) was measured immediately after implant placement, and on the day of sacrifice (3 months after the implant placement). Histological and histomorphometric procedures and analysis were performed to assess all samples, measuring crestal bone loss (CBL) and bone-to-implant contact (BIC). The data obtained were compared with statistical significance set at p < 0.05. The ISQ results showed a similar evolution between the groups at the two evaluation times, although higher values were found in the G1 group under all conditions. Within the limitations of this animal study, it may be concluded that implant macrogeometry is an important factor influencing guided bone regeneration in buccal defects. Group G1 showed better buccal bone regeneration (CBL) and BIC % at 3 months follow up, also parallel collar design can stimulate bone regeneration more than divergent collar design implants. The apical portion of the implant, with a stronger self-tapping feature, may provide better initial stability, even in the presence of a bone defect in the buccal area.

The physical characteristics of an implant surface can determine and/or facilitate osseointegration processes. In this sense, a new implant surface with microgrooves associated with plus double acid treatment to generate roughness was evaluated and compared in vitro and in vivo with a non-treated (smooth) and double acid surface treatment. Thirty disks and thirty-six conical implants manufactured from commercially pure titanium (grade IV) were prepared for this study. Three groups were determined, as described below: Group 1 (G1), where the samples were only machined; group 2 (G2), where the samples were machined and had their surface treated to generate roughness; and test group 3 (G3), where the samples were machined with microgrooves and the surface was treated to generate the roughness. For the in vitro analysis, the samples were submitted to scanning microscopy (SEM), surface profilometry, the atomic force microscope (MFA) and the surface energy test. For the in vivo analyses, thirty-six implants were placed in the tibia of 9 New Zealand rabbits in a randomized manner, after histological and histomorphometric analysis, to determine the level of contact between the bone and implant (BIC%) and the bone area fraction occupancy (BAFO%) inside of the threads. The data collected were statistically analyzed between groups ( p < 0.05). The in vitro evaluations showed different roughness patterns between the groups, and the G3 group had the highest values. In vivo evaluations of the BIC% showed 50.45 ± 9.57% for the G1 group, 55.32 ± 10.31% for the G2 group and 68.65 ± 9.98% for the G3 group, with significant statistical difference between the groups ( p < 0.0001). In the BAFO% values, the G1 group presented 54.97 ± 9.56%, the G2 group 59.09 ± 10.13% and the G3 group 70.12 ± 11.07%, with statistical difference between the groups ( p < 0.001). The results obtained in the evaluations show that the surface with microgrooves stimulates the process of osseointegration, accelerating the healing process, increasing the contact between the bone and the implant and the area of new bone formation.

The purpose of this work was to evaluate the behavior of different membranes and bone filling materials used to fill critical defects in rabbit calvaria. Four defects were prepared in the cranial calvaria of female rabbits. They were randomly divided into three subgroups according to the type of barrier membrane to be used. Four animals carried cross-linked bovine collagen membranes (Mem-Lok, Bio-Horizons, Birmingham, AL, USA)), four human fascia lata membranes (Tissue, Inbiomed SA, Córdoba, Argentina) and four human chorioamniotic membranes (Tissue. Inbiomed SA, Córdoba, Argentina). The defects were filled with the deproteinized bovine bone particulate Bio-Oss® (Geistlich-Pharma AG, Wolhusen, Switzerland), with particulate human hydroxyapatite MinerOss® (Bio-Horizons, Birmingham, AL, USA), with particulate dental material (Tissue Bank Foundation, Inbiomed S.A., Córdoba, Argentina), and the last one was left without the addition of filler material. In the first group of four specimens, a resorbable cross-linked bovine collagen membrane was placed over the skull and defects, without additional fixing. In the second group, a human fascia lata membrane was placed, without additional fixing. In the third group, a human chorioamniotic membrane was placed, without additional fixing. The animals were sacrificed at 4 and 8 weeks. The highest percentages of relative radiological density (average) were recorded considering the amnio-chorionic membranes (83.63%) followed by collagen (81.44%) and finally the fascia lata membranes (80.63%), but the differences were not statistically significant (p > 0.05). The sites grafted with a decellularized tooth (96.83%) and Bio-Oss (88.42%), recorded the highest percentages of radiological density but did not differ significantly from each other (subset 2). The three membranes used did not show statistical differences between them, in any of the two time periods used. There were statistical differences between the filling materials evidencing the presence of a large quantity of calcified material in the defects treated with particulate tooth and deproteinized bovine bone and while smaller amounts of calcified material were registered in the case of defects treated with human hydroxyapatite and those that were not treated.

Haemorrhagic disorders combined with soft tissue inflammation and infection may lead to severe bleeding complications before, during or after dental treatment. In selected cases, a combined therapeutic approach involving clinical therapies and systemic and local medication could improve the treatment outcomes and the patient's quality of life. This clinical case report, presents for the first time a successful combined approach, completed in a 38-year-old male patient with severe type-B haemophilia in which an infected tooth was extracted, an immediate implant was inserted, bone grafting was performed and early implant loading was successfully applied. In addition to the clinical therapy, medication was provided orally, systemically and locally, thus preventing the haemorrhagic complications and improving the patient's quality of life., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: The aim of this study was to perform an in vivo histological comparative evaluation of bone formation around titanium (machined and treated surface) and zirconia implants. For the present study were used 50 commercially pure titanium implants grade IV, being that 25 implants with a machined surface (TiM group), 25 implants with a treated surface (TiT group) and, 25 implants were manufactured in pure zirconia (Zr group). The implants ( n = 20 per group) were installed in the tibia of 10 rabbits. The implants distribution was randomized ( n = 3 implants per tibia). Five implants of each group were analyzed by scanning electron microscopy and an optical laser profilometer for surface roughness characterization. Six weeks after the implantation, 10 implants for each group were removed in counter-torque for analysis of maximum torque value. The remaining samples were processed, included in historesin and cut to obtain non-decalcified slides for histomorphological analyses and histomorphometric measurement of the percentage of bone-implant contact (BIC%). Comparisons were made between the groups using a 5% level of significance ( p < 0.05) to assess statistical differences. The results of removal torque values (mean ± standard deviation) showed for the TiM group 15.9 ± 4.18 N cm, for TiT group 27.9 ± 5.15 N cm and for Zr group 11.5 ± 2.92 N cm, with significant statistical difference between the groups ( p < 0.0001). However, the BIC% presented similar values for all groups (35.4 ± 4.54 for TiM group, 37.8 ± 4.84 for TiT group and 34.0 ± 6.82 for Zr group), with no statistical differences ( p = 0.2171). Within the limitations of the present study, the findings suggest that the quality of the new bone tissue formed around the titanium implants present a superior density (maturation) in comparison to the zirconia implants.

Manipulation of implant surface characteristics constitutes a promising strategy for improving cell growth and tissue response on a variety of materials with different surface topographies. Mesenchymal progenitor cells with a capacity to respond to titanium surface stimuli and differentiate into osteoblasts were used to perform comparative tests between two different implant topographies, including their functional interaction with pre-osteoblasts directly seeded onto the implants. Functional analysis of nanostructured implant surfaces was performed by in vitro assay analysis. The machined surface of titanium implants (mach group) was used as a control and compared with a nanoparticle HA activated surface implant (nano group), developed by the deposition of pure crystalline hydroxyapatite. Cell culture on the nano group surface resulted in higher cell adhesion and cultured osteoblast viability compared with the mach group. Scanning electron microscope (SEM) images revealed a stable interaction, indicated by the presence of focal cell adhesion formation. These results together with positive mineralization assays showed the nano group to be an excellent scaffold for bone-implant integration.

In this work, the physicochemical properties and in vitro bioactivity and cellular viability of two commercially available bovine bone blocks (allografts materials) with different fabrication processes (sintered and not) used for bone reconstruction were evaluated in order to study the effect of the microstructure in the in vitro behavior. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry, mechanical resistance of blocks, mercury porosimetry analysis, in vitro bioactivity, and cell viability and proliferation were performed to compare the characteristics of both allograft materials against a synthetic calcium phosphate block used as a negative control. The herein presented results revealed a very dense structure of the low-porosity bovine bone blocks, which conferred the materials' high resistance. Moreover, relatively low gas, fluid intrusion, and cell adhesion were observed in both the tested materials. The structural characteristics and physicochemical properties of both ceramic blocks (sintered and not) were similar. Finally, the bioactivity, biodegradability, and also the viability and proliferation of the cells was directly related to the physicochemical properties of the scaffolds.

The aim of the study was to evaluate the chemical composition of crushed, extracted human teeth and the quantity of biomaterial that can be obtained from this process. A total of 100 human teeth, extracted due to trauma, decay, or periodontal disease, were analyzed. After extraction, all the teeth were classified, measured, and weighed on a microscale. The human teeth were crushed immediately using the Smart Dentin Grinder machine (KometaBio Inc., Cresskill, NJ, USA), a device specially designed for this procedure. The human tooth particles obtained were of 300⁻1200 microns, obtained by sieving through a special sorting filter, which divided the material into two compartments. The crushed teeth were weighed on a microscale, and scanning electron microscopy (SEM) evaluation was performed. After processing, 0.25 gr of human teeth produced 1.0 cc of biomaterial. Significant differences in tooth weight were found between the first and second upper molars compared with the lower molars. The chemical composition of the particulate was clearly similar to natural bone. Scanning electron microscopy⁻energy dispersive X-ray (SEM⁻EDX) analysis of the tooth particles obtained mean results of Ca% 23.42 0.34 and P% 9.51 0.11. Pore size distribution curves expressed the interparticle pore range as one small peak at 0.0053 µm. This result is in accordance with helium gas pycnometer findings; the augmented porosity corresponded to interparticle spaces and only 2.533% corresponded to intraparticle porosity. Autogenous tooth particulate biomaterial made from human extracted teeth may be considered a potential material for bone regeneration due to its chemical composition and the quantity obtained. After grinding the teeth, the resulting material increases in quantity by up to three times its original volume, such that two extracted mandibular lateral incisors teeth will provide a sufficient amount of material to fill four empty mandibular alveoli. The tooth particles present intra and extra pores up to 44.48% after pycnometer evaluation in order to increase the blood supply and support slow resorption of the grafted material, which supports healing and replacement resorption to achieve lamellar bone. After SEM⁻EDX evaluation, it appears that calcium and phosphates are still present within the collagen components even after the particle cleaning procedures that are conducted before use., Competing Interests: The authors declare no conflicts of interest.

Aim and objectives: It is well known that the transcription factor NF-κB regulates multiple aspects of innate and adaptive immune functions and functions as a pivotal mediator of inflammatory responses. In the present study, we evaluated the trauma generated (inflammatory reaction) after osteotomy bone surgical procedures and placement of implants in the femoral cortical bone of Wistar rats. Surgical stress was evaluated measuring the release and activation of the NF-κB factor. Materials and Methods: Rats were divided into four groups (n = 10) and submitted to different surgical treatments: Control Group (G1 group), only bone perforation was performed without irrigation; Implant Group (G2 group), a titanium implant was inserted after bone perforation without irrigation; Irrigated Group (G3 group) perforations were performed with intense irrigation; and Vitaminic Compound Group (G4 group) surgical perforation was performed without irrigation and a vitaminic compound containing the principal ions present in the natural bone structure was used to fill the bone defect. All animals were euthanized six hours after the surgical procedure and NF-κB levels were determined through immunohistochemical stain followed by direct counting of labeled and unlabeled osteocytes. Results: Among different treated groups, the overall mean of the NF-κB positive cell count in all positions were higher for G1 group (33.4 ± 2.45 cells). NF-κB values were lower in the G2 group (28.9 ± 2.70 cells), whereas in the G3 group (24.3 ± 2.72 cells) as well as in G4 group still lesser NF-κB positive cells were counted (26.5 ± 2.60 cells). Conclusions: The results here presented suggest that maneuvers performed during osteotomy procedures can significantly affect inflammation levels. The NF-κB activation during the surgical procedures can be minimized and/or controlled thought the adequate irrigation or application of adequate substances., Competing Interests: The authors declare no conflict of interest.

This in vivo study assessed (hard and soft) peri-implant tissue remodeling around implants with micro-ring and open-thread neck designs placed in a dog model. Twenty histological sections corresponding to four different implant designs that were placed in America Foxhound dogs were obtained from previous studies. All the implants had been placed under identical conditions and were divided into four groups: Group A, micro-rings on implant neck plus 0.5 mm refined surface; Group B, micro-rings on implant neck; Group C, open-thread neck; and, Group D, double-spiral neck. Eight weeks after surgery, the integrated implants were removed and processed for histological examination. Crestal bone loss and bone-to-implant contact was greater for micro-ring necks than open-thread necks. Soft tissues showed significant differences on both buccal and lingual aspects, so that the distance from peri-implant mucosa to the apical portion of the barrier epithelium was smaller in the micro-ring groups. So, in spite of generating greater bone-to-implant contact, implants with micro rings produced more bone loss than open-thread implants. Moreover, the outcomes that were obtained IPX implants smooth neck design produced less bone loss in the cervical area, following by Facility implants when compared with the other open thread and microthreaded implant designs. Implant thread design can influence on bone remodeling in the cervical area, related to bundle bone preservation.

The aim of this study was to compare the implant stability and bone resorption and formation of two different extra-short implant designs with different diameter rings placed in a dog´s maxilla. Thirty-six extra-short, 5 mm diameter × 4 mm length (Short DM ® , Bioner Sistemas Implantológicos, Barcelona, Spain), delayed implants were placed in each hemimaxilla of six dogs at the bone crest level. Eighteen implants of each design (wide and narrow ring) were installed. After 8 and 12 weeks of healing, histomorphometric analyses of the specimens were carried out to measure the crestal bone level values and the tissue thickness around the wide and narrow ring implant designs. In the microscopic analysis, less buccal bone resorption was observed in the narrow ring implants with a statistical significance ( p < 0.001). For the peri-implant tissue thickness, the distance from the implant shoulder to the external portion of the epithelium was significantly higher for the implants installed with a wide ring with statistical significance ( p < 0.001). Our findings suggest that the amount of peri-implant tissues (crestal bone loss) after remodeling over a period of 12 weeks was smaller in the narrow ring extra-short implant installed in the healed maxilla, compared with the wide ring extra-short implants.

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Background: The objective of the present histologic animal study was to analyze whether roughness of the titanium surface can influence and/or stimulate the bone growth in defects filled with the blood using a rabbit tibia model., Materials and Methods: Forty sets (implant and abutment), dental implant (3.5 mm in diameter and 7 mm in length) plus healing abutment (2.5 mm in diameter), were inserted in the tibiae of 10 rabbits. Moreover, twenty titanium discs were prepared. The abutment and discs were treated by 4 different methods and divided into 4 groups: (group A) machined abutments (smooth); (group B) double acid etching treatment; (group C) treatment with blasting with particles of aluminum oxide blasted plus acid conditioning; (group D) treatment with thorough blasting with particles of titanium oxide plus acid conditioning. The discs were used to characterize the surfaces by a profilometer and scanning electronic microscopy., Results: After 8 weeks, the new bone formation around the sets of the samples was analyzed qualitatively and quantitatively in relation to bone height from the base of the implant and presence of osteocytes. Group C (1.50±0.20 mm) and group D (1.62±0.18 mm) showed bone growth on the abutment with higher values compared to group A (0.94±0.30 mm) and group B (1.19±0.23 mm), with significant difference between the groups (P < 0.05). In addition, osteocyte presence was higher in groups with surface treatment related to machined (P < 0.05)., Conclusions: Within the limitations of the present study, it was possible to observe that there is a direct relationship between the roughness present on the titanium surface and the stimulus for bone formation, since the presence of larger amounts of osteocytes on SLA surfaces evidenced this fact. Furthermore, the increased formation of bone tissue in height demonstrates that there is an important difference between the physical and chemical methods used for surface treatment.

Objectives : The objective of this study was to evaluate new bone formation derived from freshly crushed extracted teeth, grafted immediately in post-extraction sites in an animal model, compared with sites without graft filling, evaluated at 30 and 90 days. Material and Methods : The bilateral premolars P2, P3, P4 and the first mandibular molar were extracted atraumatically from six Beagle dogs. The clean, dry teeth were ground immediately using the Smart Dentin Grinder. The tooth particles obtained were subsequently sieved through a special sorting filter into two compartments; the upper container isolating particles over 1200 &mu;m, the lower container isolated particles over 300 &mu;m. The crushed teeth were grafted into the post-extraction sockets at P3, P4 and M1 (test group) (larger and smaller post-extraction alveoli), while P2 sites were left unfilled and acted as a control group. Tissue healing and bone formation were evaluated by histological and histomorphometric analysis after 30 and 90 days. Results : At 30 days, test site bone formation was greater in the test group than the control group ( p < 0.05); less immature bone was observed in the test group (25.71%) than the control group (55.98%). At 90 days, significant differences in bone formation were found with more in the test group than the control group. No significant differences were found in new bone formation when comparing the small and large alveoli post-extraction sites. Conclusions : Tooth particles extracted from dog&rsquo;s teeth, grafted immediately after extractions can be considered a suitable biomaterial for socket preservation., Competing Interests: The authors declare no conflict of interest.

The aim of this study was to evaluate osseointegration and crestal bone height in implants with a triangular cervical design in comparison with a standard rounded cervical design. The control group consisted of 24 implants with a standard cervical design, and the test group of 24 implants with a triangular cervical design. The implants were inserted in healed bone in six American Foxhounds. Crestal bone height and tissue thickness in the cervical portion were measured after 12 weeks healing. Data analysis found mean crestal bone loss of: 0.31 ± 0.24 mm on the buccal side, 0.35 ± 0.14 mm on the lingual in the test group, and 0.71 ± 0.28 mm buccal loss, and 0.42 ± 0.30 mm lingual in the control group; with statistically significant differences on the buccal aspect ( p = 0.0019). Mean tissue thickness in the test group was 1.98 ± 0.17 mm on the buccal aspect, and 2.43 ± 0.93 mm in the lingual; in the control group it was 2.48 ± 0.61 mm buccal thickness, and 2.88 ± 0.14 mm lingual, with significant differences on both aspects ( p = 0.0043; p = 0.0029). The results suggest that greater thickness of peri-implant tissue can be expected when the triangular cervical implant design is used rather than the standard cervical design., Competing Interests: The authors declare no conflict of interest.

Background: The aim of this study was to compare histologically the dimensional behavior of peri-implant tissues during osseointegration of immediately exposed or submerged implant placement in fresh extraction and healed sites., Methods: Four fresh extraction and four delayed implant sites were placed in each hemimandible of five dogs at the bone crest level. In 2 implants of each side were installed a healing abutment (exposed) and two cover screw (submerged) and formed four groups: implant installed in fresh extraction submerged (group 1), implants in fresh extraction immediately exposed (group 2), implants installed in healed site submerged (group 3), and implants in healed site immediately exposed (group 4). After 12 weeks of healing period, histomorphometric analyses of the specimens were carried out to measure the crestal bone level values and the tissue thickness in the implant shoulder portion., Results: The measure of crestal bone level showed some higher values for implants installed in fresh extraction sites in the buccal aspect: 1.88 ± 0.42 mm for group 1 and 2.33 ± 0.33 mm for group 2, with statistical significance among all four groups tested (P < 0.001). For peri-implant tissue thickness, a significative higher statistical difference (P < 0.001) for implants installed in healed sites (groups 3 and 4) was found., Conclusions: Within the limitations of the present animal study, our findings suggest that the implants placed in fresh extraction or healed site and with regards to the moment of exposition (immediately or no) are important factors to the amount of peri-implant tissues after remodeling over a period of 12 weeks. The null hypothesis was rejected.

The aim of this study was to evaluate the soft tissue thickness and marginal bone loss around dental implants with sloped micro-threaded shoulder (30° angle) in comparing with conventional design, inserted 30° degrees angulated in post extraction sockets and immediate loaded with temporary prosthesis simulating the all-on-four protocol. Materials and Methods: Six fox hound dogs received forty-eight post extraction dental implants with the different diameter and length (Medentika, Germany), but with different neck configurations. Two group of implants were inserted 1mm subcrestal [corrected]. Control group has a micro-threaded neck and the Test group has a sloped microthreaded neck. Immediate loading was applied using a constructed metallic structure. After three months, soft and hard tissue levels were assessed by histomorphometric analysis. Results: The mean soft tissue thickness (STT) was 2.5 ± 0.2 mm for the Control group and 3.3 ± 0.3 mm for Test group ( p = 0.036), meanwhile the mean marginal bone loss (MBL) was 1.53 ± 0.34 mm for Control group and, 1.62 ± 0.22 mm for Test group ( p > 0.05). Conclusions: Within the limitations of this experimental model in dogs, the findings showed that dental implants with microthreaded and microthreaded sloped necks installed in immediate post extraction sites with immediate load, presented a comparable perimplant tissue behavior., Competing Interests: The authors declare no conflict of interest.

This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C₂S) cement. Biphasic α´ L + β-C₂S ss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C₂S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement's surface after soaking in SBF. The cell attachment test showed that α´ L + β-C₂S ss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration., Competing Interests: The authors declare no conflict of interest.

The aim of the present study was to monitor implant stability after sinus floor elevation with two biomaterials during the first six months of healing by resonance frequency analysis (RFA), and how physico-chemical properties affect the implant stability quotient (ISQ) at the placement and healing sites. Bilateral maxillary sinus augmentation was performed in 10 patients in a split-mouth design using a bobine HA (BBM) as a control and porcine HA (PBM). Six months after sinus lifting, 60 implants were placed in the posterior maxilla. The ISQ was recorded on the day of surgery from RFA at T1 (baseline), T2 (three months), and T3 (six months). Statistically significant differences were found in the ISQ values during the evaluation period. The ISQ (baseline) was 63.8 ± 2.97 for BBM and 62.6 ± 2.11 for PBM. The ISQ (T2) was ~73.5 ± 4.21 and 67 ± 4.99, respectively. The ISQ (T3) was ~74.65 ± 2.93 and 72.9 ± 2.63, respectively. All of the used HAs provide osseointegration and statistical increases in the ISQ at baseline, T2 and T3 (follow-up), respectively. The BBM, sintered at high temperature with high crystallinity and low porosity, presented higher stability, which demonstrates that variations in the physico-chemical properties of a bone substitute material clearly influence implant stability., Competing Interests: The authors declare no conflict of interest.

Detailed information about graft material characteristic is crucial to evaluate their clinical outcomes. The present study evaluates the physico-chemical characteristics of two xenografts manufactured on an industrial scale deproteinized at different temperatures (non-sintered and sintered) in accordance with a protocol previously used in sinus lift procedures. It compares how the physico-chemical properties influence the material's performance in vivo by a histomorphometric study in retrieved bone biopsies following maxillary sinus augmentation in 10 clinical cases. An X-ray diffraction analysis revealed the typical structure of hydroxyapatite (HA) for both materials. Both xenografts were porous and exhibited intraparticle pores. Strong differences were observed in terms of porosity, crystallinity, and calcium/phosphate. Histomorphometric measurements on the bone biopsies showed statistically significant differences. The physic-chemical assessment of both xenografts, made in accordance with the protocol developed on an industrial scale, confirmed that these products present excellent biocompatibilitity, with similar characteristics to natural bone. The sintered HA xenografts exhibited greater osteoconductivity, but were not completely resorbable (30.80 ± 0.88% residual material). The non-sintered HA xenografts induced about 25.92 ± 1.61% of new bone and a high level of degradation after six months of implantation. Differences in the physico-chemical characteristics found between the two HA xenografts determined a different behavior for this material., Competing Interests: The authors declare no conflict of interest.

Some studies have demonstrated that in vivo degradation processes are influenced by the material's physico-chemical properties. The present study compares two hydroxyapatites manufactured on an industrial scale, deproteinized at low and high temperatures, and how physico-chemical properties can influence the mineral degradation process of material performance in bone biopsies retrieved six months after maxillary sinus augmentation. Residual biomaterial particles were examined by field scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to determine the composition and degree of degradation of the bone graft substitute material. According to the EDX analysis, the Ca/P ratio significantly lowered in the residual biomaterial (1.08 ± 0.32) compared to the initial composition (2.22 ± 0.08) for the low-temperature sintered group, which also presented high porosity, low crystallinity, low density, a large surface area, poor stability, and a high resorption rate compared to the high-temperature sintered material. This demonstrates that variations in the physico-chemical properties of bone substitute material clearly influence the degradation process. Further studies are needed to determine whether the resorption of deproteinized bone particles proceeds slowly enough to allow sufficient time for bone maturation to occur., Competing Interests: The authors declare no conflict of interest.

The aim of this study was to predict the fatigue life of two different connections of a dental implant as in load transfer to bone. Two three-dimensional models were created and assembled. All models were subjected to a natural masticatory force of 118 N in the angle of 75° to the occlusal plane. All degrees of freedom in the inferior border of the cortical bone were restrained, and the mesial and distal borders of the end of the bone section were constrained. Fatigue material data and loads were assumed as random variables. Maximum principal stresses on bone were evaluated. Then, the probability of failure was obtained by the probabilistic approach. The maximum principal stress distribution predicted in the cortical and trabecular bone is 32 MPa for external connection and 39 MPa for internal connection. A mean life of 103 and 210 million cycles were obtained for external and internal connection, respectively. Probability cumulative function was also evaluated for both connection types. This stochastic model employs a cumulative damage model and probabilistic finite element method. This methodology allows the possibility of measured uncertainties and has a good precision on the results.

It is well known that dental implants have a high success rate but even so, there are a lot of factors that can cause dental implants failure. Fatigue is very sensitive to many variables involved in this phenomenon. This paper takes a close look at fatigue analysis and explains a new method to study fatigue from a probabilistic point of view, based on a cumulative damage model and probabilistic finite elements, with the goal of obtaining the expected life and the probability of failure. Two different dental implants were analysed. The model simulated a load of 178 N applied with an angle of 0°, 15°, and 20° and a force of 489 N with the same angles. Von Mises stress distribution was evaluated and once the methodology proposed here was used, the statistic of the fatigue life and the probability cumulative function were obtained. This function allows us to relate each cycle life with its probability of failure. Cylindrical implant has a worst behaviour under the same loading force compared to the conical implant analysed here. Methodology employed in the present study provides very accuracy results because all possible uncertainties have been taken in mind from the beginning.

The aim of this study was to evaluate the effectiveness of techniques for soft tissue augmentation in the placement of immediate implants with and without provisionalization and to assess the quality of the reports in the literature. Randomized clinical trials, prospective clinical trials, and case series were included in this review. Clinical questions were formulated and organised according to the PICOS strategy. An electronic search was performed in PubMed, Cochrane Central Register of Controlled Trials, Scopus, and ISI Web up until June 2016. Interexaminer agreement on eligibility (k = 0.842; p = 0.103) and quality (k = 0.933; p < 0.001) was high. Methodological approaches were assessed using criteria based on design related forms designed by the Dutch Cochrane Collaboration. Finally, 14 papers were identified. In two studies, the implant survival was 90%; for the rest of the studies it was 100%. All studies reported favourable aesthetic, biological, and radiographic outcomes. Surgical and biomechanical complications of this technique were not relevant. This technique effectively compensates for the expected loss of volume of the oral soft tissues and maintains high success rates with good aesthetic results over time.

Titanium (Ti) is one of the most widely used biomaterials for manufacturing dental implants. The implant surface properties strongly influence osseointegration. The aim of the present study was to in vitro investigate the characteristics of Ti dental implants in terms of mutagenicity, hemocompatibility, biocompatibility, osteoinductivity and biological safety. The Ames test was used to test the mutagenicity of the Ti dental implants, and the hemolysis assay for evaluating their hemocompatibility. Human adipose - derived stem cells (ADSCs) were then seeded onto these implants in order to evaluate their cytotoxicity. Gene expression analyzing with real-time PCR was carried out to investigate the osteoinductivity of the biomaterials. Finally, the genetic stability of the cells cultured onto dental implants was determined by karyotyping. Our results demonstrated that Ti dental implants are not mutagenic, do not cause hemolysis, and are biocompatible. The MTT assay revealed that ADSCs, seeded on Ti dental implants, proliferate up to 30 days in culture. Moreover, ADSCs loaded on Ti dental implants show a substantial expression of some osteoblast specific markers, such as COL1A1, OPN, ALPL, and RUNX2, as well as chromosomal stability after 30 days of culture in a medium without osteogenic factors. In conclusion, the grit-blasted and acid-etched treatment seems to favor the adhesion and proliferation of ADSCs and improve the osteoinductivity of Ti dental implant surfaces.

The aim of this study was to assess the potential genotoxicity of dental implants, evaluating biomarkers of DNA damage (micronuclei and/or nuclear buds), cytokinetic defects (binucleated cells) and the presence of trace metals in gingival cells of patients with implants, comparing these with a control group. A total of 60 healthy adults (30 patients with dental implants and 30 control patients without) were included in the study. Medical and dental histories were made for each including life-style factors. Genotoxicity effects were assessed by micronucleus assays in the gingival epithelial cells of each patient; 1,000 epithelial cells were analyzed, evaluating the frequency of micronucleated cells and other nuclear anomalies. The concentration of metals (Al(27), Ag(107), Co (59), Cr (52), Cu(63), Fe(56), Sn(118), Mn(55), Mo(92), Ni(60), Pb(208), Ti(47)) were assayed by means of coupled plasma-mass spectrophotometry (ICP-MS). The frequency of micronuclei in the patient group with implants was higher than in the control group but without statistically significant differences (P > 0.05). Similar results were found for binucleated cells and nuclear buds (P > 0.05). For metals assayed by ICP-MS, significant differences were found for Ti(47) (P ≤ 0.045). Univariate analysis identified a significant association between the presence of micronuclei and age. Dental implants do not induce DNA damage in gingival cells, the slight effects observed cannot be indicated as biologically relevant.

Recently, porous titanium granules (PTGs) have been indicated for the preservation of the dimensions of post-extraction sockets, as a filler in sinus lift procedures and for the treatment of peri-implant and periodontal defects, based on the osteoconductivity and dimensional stability of the titanium granules. However, there is a lack of information regarding the use of this material in larger defects and in conjunction with membranes. The objective of this study is to test the behavior of PTGs used to fill critical size defects in rabbit tibiae, with and without membranes. Critical defects were created in both tibiae of rabbits, divided randomly into three groups: Group A (defect filled with PTG), Group B (defect filled with PTG+collagen membrane) and a control group (empty defect). After six weeks, histomorphometric analysis was performed. The results showed more defect closures at the cortical area (87.37%±2.2%) and more bone formation at the marrow area (57.6%±1.3%) in Group B, in comparison with the other groups (P<0.05); the use of membranes improved the material stability expressed as more percentages of the original material when membranes were used (P<0.05). Finally, inflammatory reactions were observed when the granules were not protected by membranes. In spite of the limitations of this animal study, it may be concluded that PTG particles are osteoconductive and allow bone growth. The PTG particles must be covered by a membrane, especially when grafting larger defects, in order to control particle migration, promote clot stabilization and separate the PTG graft from undesired soft tissue cells.

Background/aim: The modification of implant surfaces could affect mechanical implant stability as well as dynamics and quality of peri-implant bone healing. The aim of this 3-month experimental study in dogs was to investigate implant stability, marginal bone levels and bone tissue response to zirconia dental implants with two laser-micro-grooved intraosseous surfaces in comparison with nongrooved sandblasted zirconia and sandblasted, high-temperature etched titanium implants., Methods: Implant surface characterization was performed using optical interferometric profilometty and energy dispersive X-ray spectroscopy. A total of 96 implants (4 mm in diameter and 10 mm in length) were inserted randomly in both sides of the lower jaw of 12 Fox Hound dogs divided into groups of 24 each: the control (titanium), the group A (sandblasted zirconia), the group B (sandolasted zirconia plus microgrooved neck) and the group C (sandblasted zirconia plus all microgrooved). All the implants were immediately loaded. Insertion torque, periotest values, radiographic crestal bone level and removal torque were recorded during the 3-month follow-up. Qualitative scanning electon microscope (SEM) analysis of the bone-implant interfaces of each group was performed., Results: Insertion torque values were higher in the group C and control implants (p < 0.05). Periotest values increased in all the periods in proportion to the extent of microgrooving as follows: the group C > the control > the group B > the group A (p < 0.05). Radiographic measurements showed minimal crestal bone loss at 3 months for microgrooved zirconia implants (groups C and B) and control implants compared with the group A implants (p < 0.05). The removal torque values increased with time for all the groups as follows: the group C > the control > the group B > the group A (p < 0.05). SEM showed that implant surfaces of the groups B and C had an extra bone growth inside the microgrooves that corresponded to the shape and direction of the microgrooves., Conclusion: The addition of microgrooves to the entire intraosseous surface of zirconia dental implants enhances primary and secondary implant stability, promotes bone tissue ingrowth and preserves crestal bone levels.

This article reports the structure and morphology of the in vivo interface between implants composed of either a tricalcium phosphate (αTCP) or αTCP doped with 3.0 wt% dicalcium silicate (αTCP(ss)) ceramic, and natural bone of rabbit tibias. Both interfaces developed a new bone layer in direct contact with the implants after 4 and 8 weeks of implantation. The specimens were examined using analytical scanning and transmission electron microscopy, up to the lattice plane resolution level. Degradation processes of the implants developed at the interfaces encouraged osseous tissue ingrowth into the periphery of the material, changing the microstructure of the implants. The ionic exchange initiated at the implant interface with the environment was essential in the integration process of the implant, through a dissolution–precipitation–transformation mechanism. The interfaces developed normal biological and chemical activities and remained reactive over the 8-week period. Organized collagen fibrils were found at the αTCP(ss)/bone interface after 4 weeks, whereas a collagen-free layer was present around the Si-free αTCP implants. These findings suggest that the incorporation of silicate ions into αTCP ceramic promotes processes of the bone remodeling at the bone/αTCP(ss) interface, hence the solubility rate of the aTCP(ss) material decreased.

Objectives. The aim was to evaluate survival and success rates, soft tissue health, and radiographic marginal bone loss (MBL) of zirconia implants placed in the esthetic and posterior areas of the jaws and in association with multiple or single implant restorations after at least 6 months of definitive restoration. Material and Methods. 35 one-piece zirconium implants were utilized for single or partially edentulous ridges rehabilitation. All implants received immediate temporary restorations and six months after surgery were definitively restored. Every 6 months after implant placement, a clinical-radiographic evaluation was performed. For each radiograph, the measurements of MBL were calculated. Results. The results showed that the mean MBL at 48-month followup was 1.631 mm. The mean MBL during the first year of loading was not more significant for implants placed in the first molar regions than for those positioned in other areas. Moreover, no differences in marginal bone level changes were revealed for multiple and single implants, whereas MBL in the first year was observed to be slightly greater for implants placed in the maxilla than for those placed in the mandible. Conclusion. Zirconia showed a good marginal bone preservation that could be correlated with one-piece morphology and characteristics of zirconia implants.