Gustafssonjohannessen1330

maging assessment is expected to be adopted in future studies.PURPOSE The purpose of this study was to investigate the resistance against rotation of a two-piece abutment with or without the presence of a positioning hex in tapered internal connection implant systems. MATERIALS AND METHODS A tapered internal connection implant with an 11-degree internal oblique angle was placed into a constructed three-dimensional (3D) bone model. Two types of abutments were compared hex-type abutments with a positioning hex and two-piece round-type nonhex abutments. Vertical compressions equivalent to the screw tightening torque of 30 Ncm and 40 Ncm were applied to the abutment screws. A horizontal load of 150 N was applied to the superstructure to create moments. The contact area between the implant and abutment was compared and analyzed. The rotational displacement of the abutments was investigated as well. RESULTS When a preload equivalent to 40 Ncm of tightening torque was applied, the round-type abutment exhibited a larger contact area than the hex-type abutment by approximately 2.5% to 3.5% in contrast to the internal surface area of the implant. When the screw tightening torque of 30 Ncm was applied, the rotational displacement of the hex-type abutment was approximately 0.54 degrees and the round-type was approximately 1.16 degrees under clockwise moment loading. CONCLUSION Within the limitations of this study, it can be assumed that the hexagonal design of the abutment acts as rotational resistance against moments.PURPOSE Platelet concentrates are used for regenerative periodontal and implant therapy. Up to now, no study has reported the influence of smoking on platelet-rich fibrin membranes. Hence, this cross-sectional in vitro study aimed to analyze the influence of cigarette smoking on platelet morphology and fiber characteristics of both leukocyte- and platelet-rich fibrin and advanced platelet-rich fibrin membranes. MATERIALS AND METHODS Sixty blood samples from both smokers (n = 34) and nonsmokers (n = 26) based on power analysis were collected and subjected for complete blood count and platelet morphology indices (mean platelet volume, platelet distribution width, platelet-large cell ratio, and plateletcrit). Leukocyte- and platelet-rich fibrin membrane (2,700 revolutions per minute for 12 minutes) and advanced platelet-rich fibrin membrane (1,500 revolutions per minute for 14 minutes) were prepared using a standard protocol. Thirty-two platelet-rich fibrin membranes from 16 individuals were selected randomly frets.PURPOSE Peri-implantitis is an important biologic complication that can lead to implant failure. Proper treatment should effectively kill bacteria, not harm the implant surface, and promote regeneration. Recently, photocatalytic coating without antibiotics or external agents was proposed to be an alternative to antibiotic therapy. The aim of this study was to evaluate the photocatalytic antibacterial effect of a new titanium implant coating made from hydroxyapatite-tryptophan complex and gray titania, which was activated by two visible lights. MATERIALS AND METHODS Titanium alloy substrate was plasma sprayed with hydroxyapatite (80 wt%) and dititanium trioxide (20 wt%) and then pressed with tryptophan. Three bacteria related to peri-implantitis, Porphyromonas gingivalis, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans, were used in this study. Six conditions were tested (1) control group (only bacteria), (2) photocatalytic sample in darkness (bacteria and coated sample in darkness), (3) red lan bacteria associated with peri-implantitis.PURPOSE The aim of this study was to evaluate the effect of implant designs with different lengths and diameters on the stress distribution in abutments, implants, and cortical and trabecular bone of the edentulous mandible via three-dimensional finite element analysis. MATERIALS AND METHODS Eight different finite models (cylindrical 3.5 × 6; cylindrical 3.5 × 10.5; cylindrical 4.5 × 6; cylindrical 4.5 × 10.5; triple cylindrical 3.5 × 6; triple cylindrical 3.5 × 10.5; triple cylindrical 4.5 × 6; and triple cylindrical 4.5 × 10.5) were created. Abutments, abutment screws, and metal-retained porcelain crowns were modeled on the implants. A 200-N oblique load was applied on the buccal cusp of the crown. The highest maximum principal (Pmax) and minimum principal (Pmin) stresses were calculated for trabecular and cortical bone, and von Mises stress values were calculated for the implant and abutment. RESULTS The triple cylindrical implant abutments showed lower stress values than cylindrical implant abutments. Thet, and bone tissue stress.PURPOSE Raloxifene, an antiresorptive drug, prevents bone loss and promotes bone formation by secondary anabolic action. The purpose of this study was to investigate the effectiveness of raloxifene on the osseointegration of implants in the rat model of the osteoporotic maxilla. selleckchem MATERIALS AND METHODS Thirty Sprague-Dawley female rats aged 10 weeks were randomly assigned to the following groups (1) raloxifene (RAL) group (n = 10), (2) ovariectomized (OVX) group (n = 10), and (3) control group (sham-operated, n = 10). Both ovaries were removed to induce osteoporosis, and the maxillary right molar was extracted. After 4 weeks, an implant was placed on the same edentulous area. Raloxifene 1 mg/kg/day was administered to the experimental animals in the RAL group, while those in the ovariectomized group and sham-operated group were given the same amount. All experimental animals were sacrificed at 4 weeks after implants were placed. Histomorphometric measurements of the bone area ratio (BA, %) and bone-to-implant coxifene on the clinical outcome of patients with poor bone quality who undergo dental implant treatment.Sugarcane yellow leaf virus (SCYLV), the causal agent of yellow leaf disease, naturally infects at least three plant species in Florida sugarcane (Saccharum spp.), the weed Columbus grass (Sorghum almum) and cultivated sorghum (S. bicolor). All three hosts are also colonized by the sugarcane aphid (Melanaphis sacchari), the main vector of SCYLV worldwide. To understand the high incidence of SCYLV observed in sugarcane commercial fields and in germplasm collections, we investigated the transmission efficiency of SCYLV from sugarcane and Columbus grass to sugarcane using the sugarcane aphid and a spider mite (Oligonychus grypus) that also tested positive for SCYLV in Florida. Healthy and SCYLV-infected leaf pieces of sugarcane and Columbus grass carrying viruliferous aphids or spider mites were transferred to virus-free plants of the yellow leaf susceptible sugarcane cultivar CP96-1252. Three- and 6-months post inoculation, the 108 aphid-inoculated plants of Columbus grass and the 90 mite-inoculated plants of sugarcane tested negative for SCYLV by tissue blot immunoassay (TBIA) or reverse transcription polymerase chain reaction (RT-PCR).