The Influence of Connection on the Microleakage Development of Implant- Supported Fixed Bridges.

PURPOSE: If bacteria penetrate through the implant-abutment connection, they may initiate inflammatory reactions in the peri-implant tissue. It seems that the type of connection plays a key role in the development of peri-implantitis. The aim of the present in vitro study was to compare the microleakage of implant-supported fixed complete arch bridges at the levels of abutment and implant. METHODS: Ten identical polyurethane model bases containing six implants each were produced using an edentulous model of the upper jaw. These models were prepared with two types of implant-supported complete arch prostheses. Five specimens were fixed at implant level and five at abutment level. The inner parts implants were inoculated with Escherichia coli (E.coli). Each implant was surrounded with closed bacteria-proof vessels to observe bacterial migration from the inner parts of implants to the nutrient solution. Samples of nutrient solution were taken at different time points up to 2 to 10 days and colony forming units were determined. RESULTS: The bacterial accumulation in the implant-supported bridges at the implant level was significantly lower than at the abutment-level (p=0.00953). CONCLUSION: For implant-supported fixed complete arch prostheses, bacterial accumulation was lower at the implant level than at the abutment-level.

Single mandibular implant study - denture satisfaction in the elderly.

To investigate whether there are differences in patients' denture satisfaction when an implant placed in the midline of the edentulous mandible is loaded either immediately or three months later, after second-stage surgery. One hundred and fifty-eight edentulous patients received a single implant in the midline of the mandible. After randomisation, it was loaded either immediately after implant placement (N = 81, group A) or three months later, after a submerged healing phase and a second-stage surgery (N = 77, group B). Patients' denture satisfaction aspects were assessed, using visual analogue scales (VAS), before treatment, one month after implant placement during the submerged healing phase (only group B) and one and four months after implant loading. The statistical analysis was performed using the Wilcoxon signed-rank and rank-sum tests. One month after loading, a significant improvement in comfort, function and stability of the mandibular denture could be observed in both groups (P ≤ 0·05). A slight but not significant improvement was found between one and four months after loading. Patients with second-stage surgery and delayed loading rated the stability and fit of the mandibular denture as significantly better than patients who had immediate loading. A single implant in the edentulous mandible significantly increased patients' denture satisfaction. After four months, stability and fit of the mandibular denture were considered better when a delayed loading protocol had been followed. A single mandibular implant in the edentulous mandible significantly increases patients' denture satisfaction, regardless of the loading protocol.