Short implants: Influence of different diameters, torques, and transmucosal heights of straight prosthetic abutments on screw preload loss after cycling.

This study evaluated the influence of different implant diameters, insertion torques, and transmucosal heights on the loosening of abutments installed on short implants, after mechanical cycling. The Morse taper connection implants (n = 96) tested were 5 mm high, divided according to the platform diameter: 4 or 6 mm. A universal abutment was coupled to each implant (with different transmucosal heights: 1 or 5 mm). The sets were subdivided into 20- and 32-Ncm torque. After the cycle fatigue test, the detorque values were measured with a digital torque indicator. After mechanical cycling, the mean detorque values obtained for the abutment with 20-Ncm insertion torque were lower than for implants with 32-Ncm insertion torque, regardless of the platform diameter or transmucosal height. In the 20-Ncm torque group, there was no statistically significant difference in the detorque values between platform diameters or transmucosal heights. Otherwise, for 32-Ncm sets, a smaller platform diameter (4 mm), and a longer transmucosal height (5 mm) showed the lowest detorque values. In conclusion, implants placed with 32-Ncm insertion torque and abutments with 1 mm transmucosal height and a 6 mm implant diameter demonstrated the highest detorque values.

Histomorphometric evaluation of different graft associations for maxillary sinus elevation in wide antral cavities: a randomized controlled clinical trial.

OBJECTIVES: Pneumatization of the maxillary sinus can make it difficult, if not impossible, to install osseointegrated implants, and undertake their eventual functional rehabilitation, which may ultimately require regenerative techniques to achieve. This randomized controlled study proposed conducting a histological evaluation of the behavior of different graft materials in wide maxillary sinuses, at a height of 8 to 10 mm from the alveolar ridge, combined with bone remnants less than 3mm. MATERIALS AND METHODS: Thirty-six patients underwent a sinus elevation procedure through the lateral window. The sinuses were randomly filled with the following materials (n=12/group): group 1, xenogenic bone + autogenous bone (ratio 70:30, respectively); group 2, xenogenic bone + L-PRF; and group 3, xenogenic bone. At 8 months, bone biopsies of engrafted sites were harvested and analyzed histomorphometrically in order to quantify newly formed bone tissue. RESULTS: The results showed a greater area of newly formed bone for G1, averaging 2678.37 (1116.40) µm2, compared with G2 at 984.87 (784.27) µm2, and G3 at 480.66 (384.76) µm2 (p < 0.05). Additionally, fewer xenogenic bone particles and a large amount of connective tissue were observed in G2. CONCLUSIONS: In maxillary sinuses with large antral cavities, autogenous bone combined with xenogenic bone seems to demonstrate better graft remodeling and improve bone formation, compared with the addition of L-PRF. CLINICAL RELEVANCE: L-PRF produces few advantages regarding new bone formation in the wide maxillary sinuses. TRIAL REGISTRATION: Brazilian Clinical Trials Registry (REBEC) number RBR-2pbbrvg.

Analysis of the Viability and Morphology of Gingival Cells on Materials Used in Novel Prosthetic Components: In Vitro Study.

AIM: The objective of this in vitro study was to evaluate the viability and morphology of human fibroblasts and keratinocytes cells, both grown on stainless steel (steel) (18Cr14Ni2.5Mo), and polyether-ether-ketone (PEEK) surfaces, hypothesizing the use of these surfaces as novel materials for prosthetic components. MATERIALS AND METHODS: Gingival human keratinocytes and gingival human fibroblasts lines were grown on discs made by steel (n = 36), PEEK (n = 36), and titanium (Ti) (Ti6A14V) (n = 36)-control. For viability assay, cultures were grown at 24 hours (TV1), 48 hours (TV2), and 72 hours (TV3) times and evaluated by the colorimetric tetrazolium assay (MTT). For morphology and cell adhesion assays, after 24 hours (TM1), 48 hours (TM2), and 96 hours (TM3) of cell culture, cells were examined by scanning electron microscopy (SEM) and analyzed at magnifications with 500×, 1,000×, and 2,500×. RESULTS: Regarding the viability, the keratinocytes did not present statistical difference on the different materials, in TV1 and TV3 times of culture. Their growth rate increased on all materials, being more expressive in steel; the fibroblasts did not present statistical difference on the different materials, in TV2 and TV3 times of culture. The growth rate of these decreased on all materials, being more expressive in PEEK. The morphology analyses show increase in cell numbers, adequate spreading, and adhesion at all cultivation times (TM1, TM2, and TM3) in both cell lines, on all materials. CONCLUSION: All materials tested are suitable for use in the manufacture of prosthetic components for implant-supported rehabilitations, considering the limitations of this study. CLINICAL SIGNIFICANCE: This work analyzes the cellular response of cells present in the human gingiva, as a way to simulate the peri-implant tissue response around novel angular prosthetic components made of stainless steel and PEEK.

TiF4 Incorporated into a Self-etching Primer in Different Concentrations: Antimicrobial Properties and Effects on Demineralisation Inhibition Around the Restoration/Enamel-Dentin Interface.

PURPOSE: To apply titanium tetrafluoride (TiF4) in an aqueous solution or incorporated into the primer of a self-etching adhesive (Clearfil SE Bond) as dentin pre-treatment and evaluate its antimicrobial effect, determine the minimum bactericidal concentraion (MBC) against Streptococcus mutans and Lactobacillus casei and analyse its potential to inhibit the development of carious lesions at the restoration interface. MATERIALS AND METHODS: For MBC, an aqueous solution or primer with different concentrations (in %) of TiF4 were used (from 0.0 to 4.0). Also, 50 cavities were prepared at the enamel/dentin junction of third molars and received the following dentin pre-treatments (n = 10): Clearfil SE Bond (CL); aqueous solution of 2.5% TiF4 + CL (T2.5%); aqueous solution of 4% TiF4 + CL (T4%); 2.5% TiF4 incorporated into the primer (P2.5%); 4% TiF4 incorporated into the primer (P4%). Cavities were restored and submitted to pH cycling to create artificial caries lesions. Microhardness tests were performed after sectioning the restorations to assess the demineralisation at margins. RESULTS: ANOVA and Tukey's tests showed that TiF4 in aqueous solution presented MBC against S. mutans and L. casei of over 2.0%. TiF4 in the primer of a self-etching adhesive presented MBC of over 1% for L. casei. For enamel, CL showed no significant differences in microhardness between the depths. CONCLUSIONS: The aqueous solution had an antimicrobial effect against Streptococcus mutans and Lactobacillus casei of over 2.0%. Pretreatment with the aqueous solution or primer did not inhibit demineralisation at enamel or dentin restoration interfaces.

Sustained Release from Ionic-Gradient Liposomes Significantly Decreases ETIDOCAINE Cytotoxicity.

PURPOSE: Etidocaine (EDC) is a long lasting local anesthetic, which alleged toxicity has restricted its clinical use. Liposomes can prolong the analgesia time and reduce the toxicity of local anesthetics. Ionic gradient liposomes (IGL) have been proposed to increase the upload and prolong the drug release, from liposomes. METHODS: First, a HPLC method for EDC quantification was validated. Then, large unilamellar vesicles composed of hydrogenated soy phosphatidylcholine:cholesterol with 250 mM (NH4)2SO4 - inside gradient - were prepared for the encapsulation of 0.5% EDC. Dynamic light scattering, nanotracking analysis, transmission electron microscopy and electron paramagnetic resonance were used to characterize: nanoparticles size, polydispersity, zeta potential, concentration, morphology and membrane fluidity. Release kinetics and in vitro cytotoxicity tests were also performed. RESULTS: IGLEDC showed average diameters of 172.3 ± 2.6 nm, low PDI (0.12 ± 0.01), mean particle concentration of 6.3 ± 0.5 × 1012/mL and negative zeta values (-10.2 ± 0.4 mV); parameters that remain stable during storage at 4°C. The formulation, with 40% encapsulation efficiency, induced the sustained release of EDC (ca. 24 h), while reducing its toxicity to human fibroblasts. CONCLUSION: A novel formulation is proposed for etidocaine that promotes sustained release and reduces its cytotoxicity. IGLEDC can come to be a tool to reintroduce etidocaine in clinical use.

Influence of Transmucosal Height on Loss of Prosthetic Abutment Torque After Mechanical Cycling.

The aim of this study was to measure and record the universal transmucosal abutment height, and then evaluate whether it influenced loosening of the abutment screw by analyzing the torque and detorque values after mechanical cycling. Thirty-six implants, model CM Unitite, with internal conical connections (3.5 × 10 mm) and respective universal prosthetic abutments (n = 36, 3.25 × 6 mm), were divided into three groups (n = 12 each) with respective transmucosal heights of 0.8, 3.5, and 5.5 mm. Insertion torque of 20 Ncm was used in accordance with the manufacturer's specifications. Afterward, the samples were submitted to fatigue tests consisting of 500,000 cycles at a frequency of 2Hz, a dynamic compressive load of 120N, and an angle of 30°. The detorque values were measured with a digital torque meter and tabulated to perform statistical analyses; a level of significance of 5% was adopted. The mean detorque values (SD) obtained were 22.83 (6.30), 22.5 (5.45), and 19.41 (4.69) Ncm for transmucosal abutments with heights of 0.8, 3.5, and 5.5 mm, respectively, and showed no statistically significant difference ( P = .262). The authors of this study concluded that the transmucosal height of prosthetic abutments submitted to mechanical fatigue did not influence the detorque values.

Behavior of MC3T3-E1 Osteoblastic Cells Cultured on Titanium and Zirconia Surfaces: An In Vitro Study.

PURPOSE: The goal from this in vitro study was to evaluate osteoblast protein expression of collagen type 1 (col 1) and osteopontin (OPN) on titanium surface treated with double etching compared with a zirconia implant surface. MATERIALS AND METHODS: Discs were selected on both surfaces with respective treatments. Mouse MC3T3-E1 osteoblastic cells were tested for cell viability using the MTT assay. Subsequently, the quantification of col 1 and OPN secreted by osteoblastic cells plated on different surfaces was evaluated by enzyme linked immunosorbent assay (ELISA). RESULTS: Regarding the cell proliferation, statistical analysis showed no significant effect of surface-time interaction and viable cell count on the surfaces of titanium versus zirconia. No statistical differences between the surfaces of titanium and zirconia on cell viability was found. The zirconia surface expression of OPN was significantly higher, which occurred in all times. Furthermore, zirconia demonstrated significantly greater in col 1 expression in 48 and 96 hours compared with titanium. CONCLUSION: In this study, the zirconia surface demonstrated OPN and col 1 expression significantly higher as compared with titanium.

Perception of changes in soft-tissue profile after Herbst appliance treatment of Class II Division 1 malocclusion.

INTRODUCTION: In this study, we sought to assess the perception of changes in soft-tissue profile after Herbst appliance treatment by comparing facial profile silhouettes before treatment, immediately after treatment, and 2 years after treatment, as examined by orthodontists, general dentists, and laypersons. METHODS: The sample comprised 21 patients (mean age, 9.5 ± 0.5 years), who were treated with the Herbst appliance for a mean period of 12 (±1.1) months. Three lateral cephalograms were obtained at different times: baseline, immediately after removal of the Herbst appliance, and 2 years after removal of the appliance. The 63 resulting profile silhouettes were evaluated by 120 examiners divided into 3 groups: orthodontists, general dentists, and laypersons. The examiners were instructed to choose their preferred profile and note how much change they perceived across profiles using a visual analog scale. RESULTS: All groups of examiners preferred the posttreatment profiles. However, on quantitative assessment, the magnitudes of changes in the profile were found to be variable and rather small, with laypersons quantifying the greatest magnitude of change. CONCLUSIONS: Early Herbst appliance treatment produced positive changes in the facial profile that were visually appreciable both immediately after removal of the appliance and 2 years after treatment.

In vitro analysis of the microbiological sealing of tapered implants after mechanical cycling.

OBJECTIVE: The aim of this in vitro study was to evaluate the mechanical behavior and bacterial microleakage at the implant/abutment-tapered interface following mechanical cycling. MATERIALS AND METHODS: Two groups of screwless (Morse taper) implants (G1 and G2) and two groups of prosthetic screwed implants (G3 and G4) were tested. One group from each model (G2 and G4) were submitted to mechanical cycling, 500,000 cycles per sample, at a load of 120 N at 2 Hz prior to analysis. Microbiological analysis was performed via immersion of all samples in an Escherichia coli-containing suspension, incubated at 37 °C. After 14 days, the abutments were removed from their respective implants, registering the removal force (G1 and G2) or reverse torque (G3 and G4), and the presence of bacterial leakage was evaluated. Scanning electron microscopy (SEM) was performed to analyze the tapered surfaces of the selected samples. The Student t, binomial, and G tests were used for statistical analysis at a 5 % significance level. RESULTS: The results showed no significant difference between removal force, reverse torque, and contamination values when comparing implants of the same type. However, when the four groups were compared, contamination differed significantly (p = 0.044), with G1 having the least number of contaminated samples (8.3 %). SEM analysis showed superficial defects and damage. CONCLUSIONS: The abutment removal force or torque was not affected by mechanical cycling. Bacterial sealing of the implant/abutment tapered interface was not effective for any condition analyzed. Imprecise machining of implant parts does not allow a sufficient contact area between surfaces to provide effective sealing and prevent bacterial leakage. CLINICAL RELEVANCE: The microscopic gap caused by unsatisfactory implant/abutment adaptation, surface irregularities, and plastic deformation of all parts enabled bacterial contamination of the oral implants.

Surface topography of resorbable porcine collagen membranes, and their effect on early osteogenesis: An in vitro study.

OBJECTIVE: Guided tissue regeneration (GTR) is based on the use of different membranes that function as sealants and barriers in specific clinical situations. Among the several tissue production methods and origins, resorbable porcine-derived membranes are the most commonly used. Because these membranes are so diverse, and have several different clinical applications, doubts linger as to their effect in stimulating osteogenesis. The objective of this study was to make an in vitro evaluation of the viability and differentiation of osteoblastic cells cultured on the surface of the following collagen membranes: Jason® (Botiss Biomaterials), Collprotect® (Botiss Biomaterials), and Bio-Gide® (Geistlich). MATERIAL AND METHODS: Fragments of the 3 resorbable collagen membranes (5 × 5 mm) were used, and pre-osteoblastic SAOS-2 cells (ATCC, USA) were plated on their porous surfaces. Evaluation of the membranes was performed at 3, 5 and 7 days, considering the following parameters: (1) topographic analysis of the different surfaces by scanning electron microscope; (2) cellular viability by MTT, (3) quantification of type I collagen and osteopontin by Elisa. The quantitative analyses were carried out using a significance level of 5%. RESULTS: Collprotect® and Jason® membranes presented a rough surface with an irregular aspect on both sides, while double-layered Bio-Gide® had one layer with a smooth surface and the other with a rough surface along each respective length. The viability assays revealed that the cells cultured the cells grown on Collprotect® showed higher viability than those grown in Bio-Gide® or Jason®, especially after 5 and 7 days. After 3 and 5 days, evaluation of type I collagen showed that the cells plated on the Jason® and Collprotect® surfaces had greater collagen secretion than those plated on BioGide®. After 7 days, an increase in osteopontin levels was observed when the cells were plated on all the experimental membranes, compared with the control group. CONCLUSION: All the tested membranes were suitable for use in GTR clinical procedures. Their indication in specific regenerative cases depends on the mechanical and biological properties of their originating tissues, thus enabling better results and assertive choices by dental professionals.

Microbiological analysis of bacterial sealing of internal conical implants with different taper angles.

The present study evaluated the effect of the taper angle of different internal conical connection implants and cyclic loading on the implant-abutment bacterial seal. A total of 96 implant-abutment sets were divided into eight groups. Four groups of different taper degrees with cyclic mechanical loading of 500,000 cycles per sample, with a 120-N load at 2 Hz before analysis [16DC (16-degree, cycled), 11.5DC (11.5-degree, cycled), 3DC (3- degree, cycled) and 4DC (4- degree, cycled)] were compared to four control groups without cyclic loading [16D (16-degree), 11.5D (11.5-degree), 3D (3-degree), and 4D (4-degree)]. Microbiological analysis was performed by immersing all samples in a suspension containing Escherichia coli and incubating them at 37°C. After 14 days, the presence of bacterial seals was evaluated. Fisher-Freeman-Halton exact tests and binomial tests were performed (5% significance level). The groups showed significant differences in bacterial seal, and mechanical load cycling improved the bacterial seal in the 3DC group. In all other groups, no significant differences in bacterial seal were found between cycled and uncycled samples. To conclude, the internal conical connection with a 3-degree taper angle showed better results than the other connection with different angles when subjected to load cycling. However, none of the angles tested were fully effective in sealing the implant-abutment interface.

Pulp-Dentin Complex Regeneration with Cell Transplantation Technique Using Stem Cells Derived from Human Deciduous Teeth: Histological and Immunohistochemical Study in Immunosuppressed Rats.

The aim of this study was to histologically verify the performance of pulp-derived stem cells used in the pulp-dentin complex regeneration. Maxillary molars of 12 immunosuppressed rats were divided into two groups: the SC (stem cells) group, and the PBS (just standard phosphate-buffered saline) group. After pulpectomy and canal preparation, the teeth received the designated materials, and the cavities were sealed. After 12 weeks, the animals were euthanized, and the specimens underwent histological processing and qualitative evaluation of intracanal connective tissue, odontoblast-like cells, intracanal mineralized tissue, and periapical inflammatory infiltrate. Immunohistochemical evaluation was performed to detect dentin matrix protein 1 (DMP1). In the PBS group, an amorphous substance and remnants of mineralized tissue were observed throughout the canal, and abundant inflammatory cells were observed in the periapical region. In the SC group, an amorphous substance and remnants of mineralized tissue were observed throughout the canal; odontoblasts-like cells immunopositive for DMP1 and mineral plug were observed in the apical region of the canal; and a mild inflammatory infiltrate, intense vascularization, and neoformation of organized connective tissue were observed in the periapical region. In conclusion, the transplantation of human pulp stem cells promoted partial pulp tissue neoformation in adult rat molars.

DoE development of ionic gradient liposomes: A successful approach to improve encapsulation, prolong anesthesia and decrease the toxicity of etidocaine.

Etidocaine (EDC) is a long-acting local anesthetic of the aminoamide family whose use was discontinued in 2008 for alleged toxicity issues. Ionic gradient liposomes (IGL) are nanostructured carriers for which an inner/outer gradient of ions increases drug upload. This work describes IGLEDC, a formulation optimized by Design of Experiments, composed of hydrogenated soy phosphatidylcholine:cholesterol:EDC, and characterized by DLS, NTA, TEM/Cryo-TEM, DSC and 1H NMR. The optimized IGL showed significant encapsulation efficiency (41 %), good shelf stability (180 days) and evidence of EDC interaction with the lipid bilayer (as seen by DSC and 1H NMR results) that confirms its membrane permeation. In vitro (release kinetics and cytotoxicity) tests showed that the encapsulation of EDC into the IGL promoted sustained release for 24 h and decreased by 50 % the intrinsic toxicity of EDC to Schwann cells. In vivo IGLEDC decreased the toxicity of EDC to Caenorhabditis elegans by 25 % and extended its anesthetic effect by one hour, after infiltrative administration, at clinically used (0.5 %) concentration, in rats. Thus, this novel drug delivery system is a promise for the possible reintroduction of EDC in clinics, aiming at the control of operative and postoperative pain.

Conditioned Media from Human Pulp Stem Cell Cultures Improve Bone Regeneration in Rat Calvarial Critical-Size Defects.

The aim of this study was to test whether lyophilized conditioned media from human dental pulp mesenchymal stem cell cultures promote the healing of critical-size defects created in the calvaria of rats. Prior to the surgical procedure, the medium in which dental pulp stem cells were cultured was frozen and lyophilized. After general anesthesia, an 8 mm diameter bone defect was created in the calvaria of twenty-four rats. The defects were filled with the following materials: xenograft alone (G1) or xenograft associated with lyophilized conditioned medium (G2). After 14 or 42 days, the animals were euthanized, and the specimens processed for histologic and immunohistochemical analysis. Bone formation at the center of the defect was observed only in the G2 at 42 days. At both timepoints, increased staining for VEGF, a marker for angiogenesis, was observed in G2. Consistent with this, at 14 days, G2 also had a higher number of blood vessels detected by immunostaining with an anti-CD34 antibody. In conclusion, conditioned media from human dental pulp mesenchymal stem cell cultures had a positive effect on the regenerative process in rat critical-size bone defects. Both the formation of bone and enhancement of vascularization were stimulated by the conditioned media.

In vitro evaluation of the suppressor potential of conditioned medium from benign myoepithelial cells from pleomorphic adenoma in malignant cell invasion.

Tumoral invasion process is the result of a complex interaction between the tumor cells and microenvironment which plays an important role in modulating the growth and invasion of the cancer. The myoepithelial cells, present in glandular organs such as the breast and salivary glands, seem to exert paracrine effects on the glandular epithelium, acting as natural tumor suppressors. To verify the influence of the benign myoepithelial cells in the invasion of malignant cells, simulating an in situ carcinoma ex pleomorphic adenoma, we have cultured three different high-potential invasive malignant tumors (breast ductal adenocarcinoma, melanoma and oral squamous cell carcinoma) in conditioned medium of myoepithelial cells from salivary gland pleomorphic adenomas using transwell chambers with 8-µm pores membrane coated with matrigel. After 96 h, quantitative analyses of the results were performed by calculating the invasion index (number of cells that invaded in relation to the total number of cells). The results showed that there was a reduction of the invasion index mean for the three different malignant tumors. This study supports a tumoral suppressor function of the myoepithelial cells from pleomorphic adenoma in in vitro invasion process.

Biologic Behavior of Pressed Lithium Disilicate Ceramic and Zirconia on Human Gingival Fibroblasts: An In Vitro Study.

This study evaluated in vitro the biologic profile of manually polished surfaces of pressed lithium disilicate (LD) ceramic compared to zirconia (Zir) in human gingival fibroblasts. Samples with a 10-mm diameter and 3-mm thickness were used. After manual polishing, the average roughness (Ra) of the samples was measured. The cell proliferation and viability of gingival fibroblasts on the surfaces were assessed at 24, 48, and 96 hours. Additionally, the morphology, cell adhesion, and type III collagen (COLIII) and vimentin (VIM) expression by fibroblasts plated onto these surfaces was analyzed. Polystyrene (Pol) was used as control for all assays. The mean Ra was 0.261 ± 0.053 µm for Zir and 0.345 ± 0.130 µm for LD. Both surfaces presented similar cell proliferation and viability (P > .05). The cell morphology demonstrated that, for both surfaces, the cells were occasionally spindle-shaped, parallel to the direction of the grooves. Compared to Pol, an upregulation of COLIII and VIM gene expression was observed by fibroblasts cultured on Zir and LD at all time points (P < .05). The characteristics presented by LD and Zir surfaces after manual polishing protocol were similar and had biologically favorable performances, thus suggesting LD as a suitable alternative to Zir in the peri-implant region for esthetic purposes.

Evaluation of the dosimetry and centralization of scout-view function in CBCT.

This study evaluated the centralization of the region of interest (ROI) in acquisition of the CBCT images, when the freely positionable scout-view (SV) function is applied. Additionally, the dosimetry of the acquired images was assessed in the SV function alone as well as in complete tomographic image in two different fields of view (FOV) (50x50 and 78x150mm). A three-location device was created to accommodate the dosimeters and the specimens, in the right, middle and left location during image acquisition. For dose assessment, thermoluminescent dosimeters were irradiated within the FOV and analyzed in a portable reader. For ROI evaluation, three specimens of gutta-percha stick were placed on the same device and the CT scans were acquired (CBCT OP 300 Maxio device, 90kV, 13mA, 85 µm voxel size, FOV of 50X50mm), with and without the SV, in three positions (3-9, 1-7 and 5-11 o'clock), simulating different regions of the mouth. Two image evaluations were performed, an objective and subjective. There was a slight percentage increase (1.36% to 1.40%) of the radiation dose with the use of SV. The distances were significantly greater in the images acquired without SV (p < 0.05). Every image obtained with SV was classified as being at the FOV's center. In conclusion, the results demonstrated that SVs function is effective to centralize the ROI in the FOV, increasing the scan precision and avoiding repetitions due to positioning errors.

Clinical, Histological, and Scintigraphic Comparative Study of the Use of Mandibular Bone Marrow and Peripheral Blood in Bone Neoformation.

MATERIALS AND METHODS: The study included 16 patients with maxillary atresia. The region was grafted with xenograft blocks associated with the following treatments: G1, the patient's peripheral blood during surgery, and G2, dripping of mandibular bone marrow blood until the xenograft was completely wet. After 7 and 14 days, scintigraphic images of the regions of interest (ROI) were taken to quantify pixels, which indicate osteogenic activity. Additionally, trephined samples obtained at the time of implant placement were stained in H&E, and newly formed bone tissue was quantified. The data were tabulated and statistically analyzed at a significance level of 5%. RESULTS: Scintigraphic data showed greater osteogenic activity with mandibular bone marrow blood (G2) at all times evaluated (p < 0.05). As for the histomorphometric analysis, a greater amount of bone tissue was observed in samples treated with mandibular bone marrow blood (G2) compared to peripheral blood (G1) (p < 0.05). CONCLUSIONS: The appositional bone reconstruction technique in the block associated with mandibular bone marrow blood increased bone neoformation and osteogenic activity compared to conventional graft treatment with peripheral blood.

In vitro analysis of prosthetic abutment and angulable frictional implant interface adaptation: Mechanical and microbiological study.

The aim of this study was to evaluate, in vitro, the microbiological sealing at the implant and different angles frictional prosthetic abutment interface, submitted or not to mechanical cycling, as well as the deactivation force and evaluation of the implant-abutment interface by scanning electron microscopy. For this study, the sealing capacity of eighty sets of abutments/implants of each angle, with and without mechanical cycling, with internal conical connection (locking tapper) (4.3 mm × 9.0 mm) constituted in Titanium alloy (Ti6Al4V), and stainless steel angled prosthetic abutment was evaluated (18Cr14Ni2.5Mo) according to ASTM F138-13a (Arcsys, FGM, Joinville, Brazil), 6 mm high and 4.2 mm in diameter at the coronary portion, and 3.5 mm high transmucosal, in 4 different angles (0, 5, 10 and 20°). After in vitro tests, 100% biological sealing was observed at the implant / prosthetic abutment interface within cycled and non-cycled conditions, for the straight, 5, 10 and 20° inclination groups. There was no statistically significant difference in the removal force of the prosthetic abutments at different angles, under non-cycled conditions; however, under mechanical loading, the deactivation force was significantly higher for straight prosthetic abutments than with 10 and 20° of angulation. Surface analysis revealed good adaptation between implants and abutments, and the presence of wear areas, independently of mechanical loading. It is concluded that the analysis of implant and prosthetic abutment interface revealed good adaptation between the parts, for all analyzed samples.