Implant Specialization: A Logical Progression or a Quagmire? No abstract available

Next-Generation Biomaterials for Bone and Periodontal Regeneration No abstract available

Clinical Factors and Cellular Responses of In Situ Human Alveolar Bone–Derived Mesenchymal Stromal Cells Associated With Early Periimplant Marginal Bone Loss: A Prospective Cohort Pilot Study Purpose: To investigate clinical factors and cellular responses of in situ human alveolar bone–derived mesenchymal stromal cells involved in early periimplant marginal bone loss. Materials and Methods: Thirty-seven completely or partially edentulous patients were enrolled in this study. Periapical radiographs were taken at the time of implant surgery, at 3-month follow-up, and at 1-year follow-up. Univariate analysis and multiple logistic regression were performed to investigate the associations between marginal bone loss and study variables. The mRNA expression levels of 21 bone-remodeling– and tissue-healing–associated genes were analyzed by subgroup. Results: Thirty-one patients with 98 implants were followed. The incidence and mean amount of bone loss were higher for overdentures than for other prosthesis and higher for the maxilla than for the mandible. The bone loss group showed lower mRNA expression levels of runt-related transcription factor-2, bone morphogenetic protein-2, and peroxisome proliferator–activated receptor gamma-2 and higher receptor activator of NKκB ligand/osteoprotegerin (RANKL/OPG) ratio. Conclusion: Within the limitations of the study, certain genes involved in bone remodeling (runt-related transcription factor-2 [Runx-2], bone morphogenetic protein-2 [BMP-2], and peroxisome proliferator–activated receptor gamma-2 [PPARγ-2]) and RANKL/OPG are correlated with early periimplant bone loss, with the type of suprastructure and the involved jaw being significant clinical factors.

Effect of Implant-Abutment Connection Type on Bone Around Dental Implants in Long-Term Observation: Internal Cone Versus Internal Hex Purpose: The purpose of this study was to evaluate the influence of the implant-abutment connection type on the bone level around dental implants in long-term observation and the survival rate for the different types of implant-abutment connections. Materials and Methods: Two groups of implants made of titanium grade 23 alloy and with sandblasted and acid‐etched (SLA) surface were included in the study: (a) the internal hex implant-abutment connection group (480 SPI dental implants; Alpha-Bio Tec, Petach Tikwa, Israel, 184 patients) and (b) the internal cone implant-abutment connection group (60 C1 dental implants; MIS Implant Technologies, Shlomi, Israel, 34 patients). Certain inclusion and exclusion criteria were applied. Marginal bone loss (MBL) around the dental implants was measured in intraoral radiographs taken with parallel technique with a film holder and by bite recording index. X-rays were performed at the moment of functional loading, and at 12, 24, 36, and 60 months after loading. The digital analysis was conducted using Dental Studio 2.0 computer software. Results: Average MBL was significantly lower in the conical connection compared with internal hex group—0.68 ± 0.59 versus 0.99 ± 0.89 mm (12 months), 0.78 ± 0.80 versus 1.12 ± 1.00 mm (24 months), 0.83 ± 0.87 versus 1.22 ± 1.03 mm (36 months), and 0.96 ± 1.02 versus 1.30 ± 1.15 mm (60 months after loading). Both groups of implants achieved a 100% survival rate. Conclusion: The internal cone connection reduced bone resorption compared with the internal hex. Both groups of implants had a 100% survival rate.

Effect of 5 Popular Disinfection Methods on Microflora of Laboratory: Customized Implant Abutments Purpose: To compare the efficacy of 5 different decontamination methods of titanium abutments and to assess their possible effects on surface roughness of titanium. Materials and Methods: Micrococcus luteus, Acinetobacter baumannii, Enterococcus faecalis, and Candida albicans were cocultured to form a multispecies biofilm on 18 titanium discs. In another group, Bacillus subtilis, a spore-forming species, was cultivated on another set of 18 titanium discs. Each group was further divided into 5 test groups: high-pressure steam cleaning (4 Mpa, 5 seconds), NaOCl (1% active chlorine, 5 minutes), H2O2 (3%, 5 minutes), GaAlAs laser (810 nm, CW, 1 W, 400-μm fiber, 1-mm distance, 1 minute), Er:YAG laser (2940 nm, pulse mode, 100 mJ, 10 Hz, 230-μm noncontact handpiece, 4-mm distance, 50/50% air/water, 1 minute), and a control group of no treatment. After each decontamination procedure, the remaining microbial load was reported as colony-forming unit/disc. To evaluate the effect of each treatment on titanium discs, surface roughness parameters including Sa, Sq, Ssk, Sku, Sal, and Sdr were measured at 6 points of each disc using an atomic force microscope. Results: Complete disinfection was achieved using high-pressure steam, NaOCl, H2O2, and Er:YAG laser. GaAlAs laser was able to reduce microbial count over 90%. Sa and Sq parameters were only increased significantly in diluted NaOCl group in comparison with control group, whereas Sdr was increased significantly in both absolute and diluted NaOCl groups. Conclusion: All the methods could decontaminate machined titanium surfaces, although complete microbial elimination was not achieved by diode laser. None of the treatments altered surface roughness significantly, except for sodium hypochlorite (NaOCl).

Osseointegration of Dental Implants in Organ Transplant Patients Undergoing Chronic Immunosuppressive Therapy Introduction: The depressive impact of immunosuppressive medications used by patients after organ transplantations is commonly known and well proven. The aim of research is the assessment of functional and esthetic results of implantoprosthetic treatment in patients subject to immunosuppressive treatment after organ transplants. Materials and Methods: The study encompassed a group of 21 patients in the course of maintenance immunosuppression after transplantation procedures, in whom altogether 24 implants were inserted. The control group comprised 15 people with 15 implants in place. The research protocol assumed replacing a single missing tooth with a titanium implant. After 4 months, a prosthetic reconstruction in the form of a single crown was performed. After 24 months, the preliminary assessment of treatment results was attempted. The measured parameter was crestal bone level (CBL). The mechanical assessment was performed by measuring the torque indispensable to locate the implant and by an objective measurement of implant stability. Results: The basic measured parameter of CBL median in the experimental group and in the control group amounted to 0.325 mm (min 0–max 0.95) and 0.5 mm (min 0.15–max 1.8), respectively. The comparison of CBL medians revealed lack of significant differences between the experimental group and the control group (P = 0.089). Conclusion: Patients with organ transplants can safely and effectively undergo dental implant treatment.

Alveolar Ridge Preservation Using Autologous Demineralized Tooth Matrix and Platelet-Rich Fibrin Versus Platelet-Rich Fibrin Alone: A Split-Mouth Randomized Controlled Clinical Trial Objective: To assess the potential of using autologous demineralized tooth matrix (aDTM) in combination with platelet-rich fibrin (PRF) membrane (aDTM/PRF) or PRF membrane alone (control) to preserve the ridge dimension and facilitate bone healing after tooth extraction. Materials and Methods: Forty premolar sockets were assigned to either the aDTM/PRF or control group. Horizontal and vertical ridge changes were evaluated at the baseline 2, 4, 6, and 8 weeks using cast-based and periapical radiographs. Results: aDTM was well tolerated in all sites without incidences of postoperative complication. The change in horizontal ridge width was significantly greater in the control compared with the aDTM/PRF group. The overall vertical marginal bone resorption on the mesial, distal, and central site in the aDTM/PRF group was not statistically different from the control group. During the first 6 weeks, the bone healing density in the aDTM/PRF group was significantly higher than that of the control group, then it converged at week 8. Conclusion: Application of aDTM with PRF membrane is useful for ridge preservation by reducing the horizontal ridge collapse and promoting bone healing as shown clinically and radiographically.

Thermal Testing of Titanium Implants and the Surrounding Ex-Vivo Tissue Irradiated With 9.3um CO2 Laser Purpose: To measure the temperature rise and surface damage of titanium dental implants and the surrounding tissue in a pig jaw during 9.3-μm carbon dioxide (CO2) laser irradiation at various durations of time. Materials and Methods: Thermal analysis tests were performed on 12 implants with the same surface. Twelve implants mounted alone or in pig jaws were laser-irradiated with a 9.3-μm CO2 laser using 3 different power settings. The temperature of the implant body and the proximal tissues was measured with a J-Type Thermocouple after being laser-irradiated with 3 different power setting for 30, 60 seconds, and 2 minutes. Scanning electron microscope (SEM) and digital microscope images were also taken of the all the implants before and after laser irradiation to detect the presence or absence of surface damage. Results: Temperature analysis showed that in all cases the implant and the proximal tissue temperatures remained around the start temperatures of the implant and tissues with fluctuations of ±3°C but never reached the upper threshold of 44°C, the temperature at which thermal injury to bone has been reported. Digital and SEM images that were taken of the implants showed an absence of surface damage at the cutting speed of 20% (0.7 W); however, cutting speeds of 30% to 100% (1.0–4.2 W) did yield surface damage. Conclusions: Laser irradiation of titanium implant surfaces using a 9.3-μm carbon dioxide laser with an average power of 0.7 W showed no increase in thermal temperature of the implant body and tissue temperatures as well as no evidence of implant surface damage.

Radiological and Histomorphometric Outcomes of Homologous Bone Graft in Postextractive Implant Sites: A 6-Year Retrospective Analysis Objectives: The aim was to investigate the in vivo efficacy of a cancellous particulate allograft bone in the regeneration of postextractive atrophic sites. Material and Methods: Ten patients were selected, and after a minimally invasive extraction of the teeth (T0), a cone beam computed tomography was performed (T1). Seven days after extraction, Puros cancellous particulate homologous graft was inserted into the elected sites together with a membrane (T2). After 4 months, a cone beam computed tomography of the sites was performed (T3). After 5 months, samples of the regenerated sites were taken contextually to implant insertion (T4). The samples were histologically and histomorphometrically analyzed. Intraoral periapical radiographs were accomplished at T4 and at the 6-year follow-up appointment (T5). Results: The mean vertical bone augmentation was of 4.1 mm in the lower jaw and of 3.35 mm in the maxilla at T3 appointment. The mean horizontal bone augmentation in the lower jaw was 2.02 and 2.15 mm in the maxilla. At T4, the mean total bone was 60.01% and the mature bone was 98.41. At the 6-year follow-up visit, the mean periimplant bone resorption was 0.14 mm (range 0–0.5 mm). Conclusions: Cancellous particulate allograft bone demonstrated excellent bone regeneration behavior both in terms of quantity and quality, and stable results over a 6-year period. Clinical Relevance: Cancellous allograft bone can be successfully used to regenerate atrophic sites.

Concentrate Growth Factors Regulate Osteogenic Dysfunction of MC3T3-E1 Cells Induced by High Glucose Through PI3K/Akt Signaling Pathway Introduction: The aim of this study is to investigate the effects of Concentrate Growth Factors Extract (CGF-e) on the proliferation and osteogenic differentiation of MC3T3-E1 cells under high glucose condition. Materials and Methods: MC3T3-E1 cells were divided into 4 groups including normal glucose (5.5-mM) group (control), high glucose (25.5-mM) group, normal glucose + CGF-e group, and high glucose + CGF-e group. The proliferation, osteogenic differentiation and mineralization of osteoblasts were evaluated, respectively, by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, cytoskeleton analysis, alkaline phosphatase activity assay, alizarin red staining, and real-time polymerase chain reaction. Western blots analysis was used to explore the role of PI3K/Akt pathway. Results: The viability, osteogenic differentiation, and mineralization of MC3T3-E1 cells were significantly decreased by high glucose. All observed osteogenic dysfunction were inhibited by CGF-e. Moreover, the PI3K/Akt pathway was activated by CGF-e. Conclusions: It was concluded that the soluble factors released by CGF could significantly attenuate high glucose-mediated MC3T3-E1 cells osteogenic dysfunction through the PI3K/Akt pathway.