One-Year Multicenter Randomised Controlled Trial Comparing OT Equator® and Locator Attachments to Retain an Early Loaded Implant Overdenture on Two Implants.

This investigation aimed to compare the effectiveness of the OT Equator® (Rhein, Bologna, Italy) and the Locator attachment systems used to retain early loaded implant-retained overdentures. This study was designed as a multicenter randomised controlled trial of parallel groups. After implant placement, the patients were randomised to receive OT Equator® attachments in the test group or Locator attachments in the control group. The outcome measures were implant and prosthetic success and survival rates, any biological and technical complication, marginal bone loss, patients' satisfaction, and periodontal parameters. Overall, 42 patients were consecutively enrolled and treated. One implant was lost in the control group, while no implants were lost in the test group. No prostheses failed in both groups. Only a few complications were experienced in both groups. The main was represented by loss of retention of the attachments (retentive caps). The OT Equator® attachment showed statistically lower periodontal parameters. In conclusion, both attachment systems were suitable for overdenture implant retention.

1-Year Evaluation of OT Bridge Abutments for Immediately Loaded Maxillary Fixed Restorations: A Multicenter Study.

OBJECTIVE: Preliminary data on survival and success rates of immediately loaded, maxillary, screw-retained, implant-supported, fixed restorations delivered on narrow and low-profile OT Equator abutments (OT Bridge, Rhein'83) were evaluated. MATERIALS AND METHODS: This retrospective study evaluated data collected from patients rehabilitated with OT Bridge prosthetic concept between November 2017 and February 2019 in six different centers. Outcome measures were implant and prosthetic survival rates, biological and technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. RESULTS: A total of 76 implants were inserted in 14 patients. Patients were followed for a mean period of 15.8 months (range = 12-24). All the patients receive OT Equator (Rhein'83) as intermediate abutments. One year after loading, one implant failed (1.3%). None of the prosthesis failed. One prosthetic complication was experienced in one patient. Three out of 76 implants were connected to the prosthetic framework using only the Seeger system, without screw. Difference in OHIP values was statistically significant (71.9 ± 8.5; p = 0.000). One year after loading, MBL was 0.21 ± 0.11 mm and p-value was 0.000. One year after loading, 8.7% of the examined implant sites present positive bleeding on probing, while 6.4% of the implant sites presented plaque. CONCLUSION: The OT Equator abutments (Rhein'83) showed successful results when used to support maxillary fixed dental prosthesis delivered on four to six implants. High implant and prosthetic survival rates, very low complications, high patient satisfaction, and good biological parameters, including only 0.2 mm of bone remodeling were experienced one year after function. Further studies are needed to confirm these preliminary results.

Multicenter Retrospective Analysis of Implant Overdentures Delivered with Different Design and Attachment Systems: Results Between One and 17 Years of Follow-Up.

PURPOSE: To analyze implant and prosthetic survival rates, complications, patient satisfaction, and biological parameters of patients rehabilitated with implant overdentures (IOV) on splinted and nonsplinted implants and different attachment systems, in function for one to 17 years. METHODS: This retrospective study evaluated data collected from patients rehabilitated with implant overdentures between January 2001 and December 2016 in nine different centers. Outcome measures were implant and prosthetic success rates, mechanical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. RESULTS: A total of 581 implants were installed in 194 patients. Patients were followed for a mean period of 60.6 months (range 6⁻206). Eighty-nine patients received 296 low profile attachment (OT Equator), 62 patients received 124 ball attachments, and 43 patients received 107 Locator attachments. In eighty-three patients the implants were splinted with computer aided design/computer aided manufacturing (CAD/CAM) or casted bar. At the last follow-up, 10 implants failed in eight patients. Statistical significance was found for failed prostheses (P = 0.0723) and complications (P = 0.0165), with better values for splinted implants. No statistically significant differences were found in proportion of implant and prosthetic failure (P > 0.05). At a five-year follow-up, proportion of complications (P = 0.0289) and failed prostheses (P = 0.0069) were statistically higher for IOV on Locator attachments. No difference was founded in MBL at one- and two-year follow-up between different attachment systems (P > 0.05). Statistically significant improvement in all the OHIP categories was reported in all the patients, after one year of function. CONCLUSIONS: Implant overdenture showed high implant and prosthetic survival rates, low complications, high patient satisfaction, and good biological parameters in the long-term follow-up. Splinting the implants may reduce number of mechanical complications. Locator attachments showed higher number of complications. Further studies are needed to confirm these preliminary results.

Aperius interspinous implant versus open surgical decompression in lumbar spinal stenosis.

BACKGROUND CONTEXT: Few studies have analyzed the results of an interspinous distraction device in patients with lumbar spinal stenosis. It is still unknown whether the outcomes of an interspinous implant are related to the severity of stenosis. PURPOSE: To determine the success rate of the Aperius implant and open decompression with the aim of defining better the indications for the two modalities of treatment. STUDY DESIGN: Comparison of two cohorts of patients with moderate or severe stenosis treated with the Aperius or by open decompression. PATIENT SAMPLE: The sample comprises 36 patients who had the Aperius implant and 35 who underwent open decompression, both groups followed prospectively. In the two cohorts, central or lateral stenosis was present in similar proportions, and in both, the patients had pure intermittent claudication or symptoms at rest and on walking. In both groups, preoperative diagnosis was made by magnetic resonance imaging (MRI). OUTCOME MEASURES: Patients of both groups were evaluated with the Zurich Claudication Questionnaire (ZCQ) and Oswestry Disability Index. The results were rated as good or poor based on the ZCQ. METHODS: The patients of both cohorts were evaluated at 1 month and 3, 6, and 12 months after operation, the final follow-up being carried out at least 2 years after surgery. Severity of stenosis was determined based on preoperative MRI scans. In 17 patients of the Aperius group, MRI studies were repeated at the 6-month or final follow-up and compared with the preoperative studies. RESULTS: Of the patients in the Aperius group, six had removal of the implant and open surgical decompression at 2 to 17 months after operation; these patients were considered to have a poor result. At the final follow-up, the result was rated as good in 47% of all patients who had had the Aperius implant. The percentage of good outcomes was 60% in moderate stenosis and 31% in severe stenosis. When considering all not reoperated patients, 57% had good outcomes; however, if only the scores in the patient satisfaction domain of the ZCQ were considered, 67% of these patients were somewhat satisfied with the result of Aperius. No significant relationship was found between patients with pure intermittent claudication and those with leg symptoms also at rest. In 71% of cases in which preoperative and postoperative MRIs were compared, no significant change in size of the spinal canal was found after operation, whereas in the remaining patients a slight increase in size of the canal was detected. In the open decompression cohort, the results were good in 80% of cases and poor in 20%. The outcomes were satisfactory in 69% of moderate stenosis, with no significant difference with the similar subgroup of the Aperius series. In severe stenosis, the 89% rate of good results was significantly higher than in the severe Aperius subgroup (p<.0001). CONCLUSIONS: The Aperius interspinous implant is poorly indicated for severe lumbar stenosis, which is significantly improved only in a small minority of cases, whereas decompression procedures ensure high chances of good results. The implant may be indicated for selected patients with moderate stenosis. The outcomes of the Aperius are not influenced by the type of clinical presentation of lumbar stenosis.

Graft vascularization is a critical rate-limiting step in skeletal stem cell-mediated posterolateral spinal fusion.

The ability of skeletal stem cells (SSCs) to direct spinal fusion (SF) upon transplantation in conjunction with osteoconductive biomaterials was investigated in a rabbit model. When tested in a mouse heterotopic transplantation assay, rabbit SSCs and Pro-Osteon 500R was osteoconductive and supported osteogenesis. When used in a SF model, the same constructs induced bone formation in periapophyseal regions (PARs). In this respect, they proved to be superior to grafts of cell-free carrier or total uncultured bone marrow-carrier constructs, used as controls. However, interapophyseal regions (IARs) remained devoid of new bone, such that true bony bridging of adjacent transverse apophyses (true SF) could not be achieved. Interestingly, this could not be predicted from high-resolution radiography. A systematic histological survey of the entire graft harvested at 6 months was essential for proper assessment of the transplantation procedure outcome. Immunohistochemical analysis of microvessel density revealed that IARs remained undervascularized, as compared to PARs, suggesting that differential vascularization could account for the absence or presence of new bone formation in the same regions. SF is an extreme model of stem cell-directed bone regeneration, requiring a combination of orthotopic (PAR) and heterotopic (IAR) bone formation. Our data show that, in this setting, graft size can be critical with respect to the necessary neovascularization, a crucial variable independent of proper osteogenic and osteoconductive competence of the cells and materials employed. Furthermore, stringent histological studies are mandatory for proper assessment of outcomes in SF studies, in which the use of mineralized materials can make radiographic assessment misleading.