Bacterial leakage in external hexagon implants with and without the interposition of a sealing-connector.

PURPOSE: To investigate whether the interposition of a sealing-connector was able to reduce the bacterial leakage in external hexagon implants. METHODS: 20 implants with external hexagon connection were used. Ten Test implant-abutment assemblies were connected with the interposition of a sealing-connector molded in the exact shape of the two opposed surfaces. Ten Control implant-abutment assemblies were connected with no sealing-connector interposed. Two types of bacteria were introduced into the internal portion of the implant, before placing the connector. The study lasted 28 days. RESULTS: All control specimens, seeded with P. aeruginosa (PA) and A. actynomycetemcomitans (AA), showed contamination of the culture medium, indicative of microbial leakage. In the Test specimens, three instances of contaminated specimens were found in the samples seeded with PA and two contaminated specimens in the ones seeded with AA, for a total of five contaminated samples out of 10. The use of the sealing-connector was able to prevent bacterial leakage in half of the samples (50%). The leakage in both groups occurred mainly in the last week of the experiment. Probably, a longer period, under the conditions of this experiment, is necessary for the migration of the bacteria, and, furthermore, an observation period of 7 or 14 days may not be enough to show microbial contamination. CLINICAL SIGNIFICANCE: Using an interface under in vitro non-loading experimental conditions, could sometimes (50%) prevent bacterial microleakage and thus possibly the risk of peri-implant site infection. Moreover, less bone resorption and the maintenance of soft tissues and esthetics might be achieved in those cases where bacterial leakage does not occur.

Three-Dimensional Bone Augmentation and Immediate Implant Placement via Transcrestal Sinus Lift: 8-Year Clinical Outcomes.

When the edentulous posterior maxilla shows severe atrophy (Cawood and Howell Class V to VI), the traditional approach requires at least two surgical procedures. The first is a sinus lift (alone or with guided bone regeneration), and the second is to position implants. This article illustrates a technique that allows three-dimensional reconstruction of the sinus, placing an allogenous fresh bone block and simultaneous implant positioning using a computer-guided implant surgery.

Three-Dimensional Bone Augmentation and Immediate Implant Placement via Transcrestal Sinus Lift: Five-Year Clinical Outcomes.

This study proposed a surgical technique that solves three-dimensional conditions of extreme bone atrophy. A total of 278 surgeries with transcrestal sinus lift and fresh frozen allogenous bone blocks were performed. A total of 1,024 implants were placed. After 60 months of observation, 969 implants were considered grade I (successful), 24 grade II (satisfactory survival), and 8 grade III (compromised survival). The cumulative success and survival rates, respectively, were 94.6% and 97.7%. This innovative procedure is very effective in selected cases. Fresh-frozen human bone allografts have been shown to be a reliable biomaterial to increase bone volume with simultaneous dental implant placement.

A New Transalveolar Sinus Lift Procedure for Single Implant Placement: The Ebanist Technique. A Technical Description and Case Series.

BACKGROUND: Nowadays, there are many techniques to compensate bone atrophies of the posterior maxilla in order to obtain an implant-supported rehabilitation. OBJECTIVE: This case series describes the Ebanist technique: a sinus lift procedure to be used in case of extremely resorbed bone crests (≤3 mm) allowing simultaneous implant placement. METHODS: With a dedicated cylindrical trephine bur, it is possible to harvest a cylinder of bone from a fresh mineralized frozen homologous bone block graft and to simultaneously create a trapdoor on the recipient site. The trapdoor cortical bone is detached from the sinus membrane and removed. Dental implant is placed into the graft before the grafting procedure since the cylindrical block, once inserted in the recipient area, is not able to oppose sufficient resistance to the torque needed for implant placement. RESULTS: Second-stage surgery and following prosthetic rehabilitation were performed after 5 months. In all cases, implant stability was manually checked and no pathological symptoms or signs were recovered at any follow-up visit. CONCLUSION: This technique can be considered a valid procedure for implant therapy on atrophic posterior upper maxillae, when the residual bone crest is extremely resorbed.