Finite element analysis of the biomechanical effects of titanium and Cfr-peek additively manufactured subperiosteal jaw implant (AMSJI) on maxilla.

The aim of this study is to examine the stresses that will occur under occlusal forces on the cortical bone, spongious bone and the subperiosteal implant systems made of Titanium and%60 Carbon fiber reinforced Polyether ether ketone (PEEK) material. Two different models of subperiosteal implant systems on maxilla made of Titanium and %60 Carbon fiber reinforced Polyether ether ketone (PEEK) material. As a result of vertical and oblique forces, the stress values and distributions on the subperiosteal implant systems and bone were examined. After applying the three different force protocols, von Mises stress, Maximum principal stress and Minimum principal stress values and distribution on the subperiosteal implant body, fixation screws, cortical and spongious bone were analyzed by finite element analysis. In all scenarios, the von Mises values ​​on the Titanium subperiosteal implant system were found to be approximately twice on the 60% carbon fiber reinforced PEEK subperiosteal implant system plates. Subperiosteal implants produced from titanium and carbon fiber reinforced PEEK material exhibited similar stress values on cortical and spongious bone. According to the results of this study, 60% Carbon fiber reinforced PEEK material can be considered as an alternative material to titanium since it exhibits similar biomechanical behavior with titanium subperiosteal implants on cortical and spongious bone. In order to be routinely used as dental subperiosteal implant material, it should be supported by long-term in vivo studies.

Comparison of Success Rate of Dental Implants Placed in Autogenous Bone Graft Regenerated Areas and Pristine Bone.

Autogenous bone grafting still has been considered as the "gold standard" and wildly used in the case of alveolar bone reconstruction. The aim of the present study is to evaluate the success rate of implants placed in autogenous block augmented ridges and implants placed in pristine bone (PB). This study included 113 patients. Fifty-three patients were treated with autogenous block grafts and particulate bone, after 6 months of healing implant placements were performed in autogenous bone augmented (ABA) areas. In 60 patients implant placement was performed, with no need for grafting and implants were placed into the PB. Follow-up data (pain, mobility, exudation from peri-implant space, success rate, marginal bone resorption) were collected after 5 years of prosthetic loading. The cumulative implant success rate at the 5-year examination was 92.45% for the ABA group and 85% for PB group. There were 3 failed implants in the ABA group and 3 in PB group. Average marginal bone loss was 1.47 mm on ABA group and 1.58 mm on PB group. No statistically significant differences for pain, exudation from peri-implant space, implant mobility, implant success, peri-implant bone loss parameters, and patient satisfaction level were found between groups. The obtained data demonstrated that the success rate of implants placed in regenerated areas are very similar to the success rate of implants those placed in PB.

Effect of Induced Membrane on Guided Bone Regeneration in an Experimental Calvarial Model.

OBJECTIVE: The aim of this study was to evaluate the effect of induced membrane on guided bone regeneration and to compare its effect with poly-tetra-flourur-ethylene (PTFE) membrane and collagen membrane. METHODS: Sixteen white Vienna rabbits were used for experiments. Initially 1 defect was created on the parietal bone of all animals and cement was placed inside the defects. After 8 weeks, the bone cements were removed, without damaging the induced membrane formed in the defect cavity. And then 2 more defects were created. All defects were filled with xsenogenic graft materials and were covered with newly formed induced membrane, d-PTFE membrane and collagen membrane. Eight animals were sacrificed at 4th week and other 8 animals were sacrificed at 8th week and all bone specimens were histologically evaluated. RESULTS: New bone formation and bone marrow ratios were significantly higher in induced membrane and d-PTFE membrane group compared to collagen membrane group (P < 0.05) at 4th week. Mature bone ratios were significantly higher in induced membrane and d-PTFE membrane group compared to collagen membrane group (P < 0.05) at 8th week. The best CD31 value was detected with d-PTFE membrane group at 4th week and with induced membrane at 8th week. CONCLUSION: Induced membrane can act as a strong barrier membrane and stimulate bone regeneration. Induced membrane technique can be accepted as a good alternative for the reconstruction of critical size defects in maxillofacial region.

Adequacy of infective endocarditis prophylaxis before dental procedures among solid organ transplant recipients.

Infective endocarditis (IE) is a life-threatening condition with high morbidity and mortality. The current IE guidelines recommend antibiotic prophylaxis only in patients with certain cardiac conditions and before certain dental procedures. However, there is not enough data about solid organ transplant (SOT) recipients. In this study, we aimed to investigate the IE prophylaxis in general dental and periodontal surgical procedures among our SOT recipients. Medical records of 191 SOT recipients (32 liver transplant recipients, 54 heart transplant recipients, and 105 kidney transplant recipients) who were admitted to our hospital between January 2016 and January 2018 were evaluated. A total of 65 patients who underwent dental procedures were included in the study. We investigated the adequacy of IE prophylaxis according to the current guidelines. Two groups were created according to whether they received antibiotic prophylaxis or not. The mean age was 44.2 ± 13.6 years, and 66.1% were male. The majority of patients (67.6%) received antibiotic prophylaxis. The most commonly used antibiotic was amoxicillin (48.8%). Among the procedures, 23.1% were classified as invasive and 76.9% were classified as noninvasive. No complication was observed after invasive and noninvasive dental procedures. There were no complications in both antibiotic prophylaxis and no-prophylaxis groups. According to our results, IE prophylaxis has been used appropriately in SOT recipients in our center. No serious infection has been reported. In addition, no complication due to antibiotic use was also observed.

Comparison of Tunnel and Crestal Incision Techniques in Reconstruction of Localized Alveolar Defects.

PURPOSE: The aim of this study was to compare the complication rates of recipient sites prepared using two incision techniques: crestal and tunnel. MATERIALS AND METHODS: In this prospective study, patients underwent augmentation procedures (68 patients; 75 sites) by the same surgeon that were performed consecutively using the crestal incision technique (27 horizontal, 10 vertical; crestal group) or the tunnel incision technique (27 horizontal, 11 vertical; tunnel group). Autogenous bone block grafts were harvested with a piezoelectric surgical device, and the grafts were fixed at the recipient sites by two titanium screws in both groups. The authors evaluated minor exposure, transient paresthesia, major exposure, permanent paresthesia, gingival recession at adjacent teeth, surgery time, and visual analog scale pain scores. RESULTS: Soft tissue dehiscence and graft failure were significantly lower in patients undergoing the tunnel technique. CONCLUSION: The tunnel incision technique significantly decreased soft tissue exposure, the most common complication of augmentation procedures with autogenous onlay bone grafts. This technique should be considered an alternative to the crestal incision technique for preparation of the recipient site.

Alveolar Ridge Splitting Versus Autogenous Onlay Bone Grafting: Complications and Implant Survival Rates.

PURPOSE: To compare the complications and implant survival rates of localized alveolar ridge deficiencies in the horizontal dimension reconstructed by alveolar ridge splitting (ARS) or autogenous onlay bone grafting (OBG). MATERIALS AND METHODS: Twenty-eight ARS and 28 OBG were performed. The survival rate of the all included implants was evaluated using the clinical and radiographical evaluation criteria of Misch et al. Temporary exposure of graft, mild infection, temporary paresthesia, and bad split were defined as minor complications; permanent exposure of graft, loss of graft, and permanent paresthesia were defined as major complications. Major and minor complications of ARS and OBG groups were statistically compared. RESULTS: When the minor and major complication rates are considered, there was not any statistically significant difference between OBG (P = 0.099) and ARS (P = 0.241) groups. The satisfactory survival rate of OBG group was 92% and was 100% in the ARS group, and the difference was not statistically significant (P = 0.116). CONCLUSION: When reconstructing vertically sufficient but horizontally insufficient alveolar ridges, ridge splitting technique could shorten the treatment period, decrease postoperative swelling and pain, eliminate the need for a second surgical site, reduce the treatment cost, and ease the patient cooperation to the surgery.