Ten‐Year Retrospective Follow‐Up Study of the TiOblast™ Dental Implant

Purpose: Long‐term results in the clinical outcome of different implant systems, including high patient numbers and a long follow‐up time, are rare. This retrospective study evaluated the cumulative survival rate of a self‐tapping, cylindrical implant system with a conical implant‐abutment connection after 10 years of prosthetic loading. Materials and Methods: A total of 516 TiOblast? implants (Astra Tech AB, Mölndal, Sweden) were placed in 108 patients. The patients were treated in the Department of Oral and Maxillofacial Surgery, Johannes Gutenberg University, Mainz, Germany, between September 1994 and May 2005. The main indications for implantation were the treatment of edentulous mandibles (74%) and partial edentulism (15%). Twenty‐three implants were placed postradiation, and a further 64 implants were irradiated after insertion. In 153 implants, a bony augmentation was conducted prior to implantation. Results: The in situ rate was 89.7% after an average implantation time of 108 months. Eighty‐three patients with 403 implants were available for investigation. Seventeen patients with 76 implants have died since 1994. Absence of osseointegration (n = 22), peri‐implantitis (n = 18), fracture of the implants (n = 9), failing of primary stability (n = 2), and implants next to tumors (n = 2) were the reasons of explantation in 26 patients. Under analysis with different implant success‐assessment criteria, the success rate showed results from 76 to 89%. Conclusion: With respect to the critical patient selection including a high number of patients with minor and major augmentations, the 10‐year clinical use of the studied implant system showed acceptable results.     

Minimizing Ports During Robotic Partial Nephrectomy

Methods:Data on 11 robot-assisted laparoscopic partial nephrectomies performed by using our technique from February 2015 through June 2015 were retrospectively analyzed. The robotic platform used was DaVinci Xi (Intuitive Surgical, Inc., Sunnyvale, California, USA) with a 3-arm setup. The AirSeal system (SurgiQuest, Milford, Connecticut, USA) was used as a port allowing simultaneous introduction of 2 instruments for the bedside surgeon, obviating the need for an additional (fourth) robotic arm. A long suction-and-irrigation device and atraumatic grasping forceps were used. Both instruments were introduced through the trocar of the AirSeal system, making simultaneous introduction and use possible. We preferred the long suction-and-irrigation device, because it minimizes collision of the instruments.Results:Mean age and BMI of the patients were 55 ±14.6 y and 29.18 ± 6.85, respectively. Seven tumors were on the right side and 4 were on the left. The mean size of the tumors was 32.45 mm (± 11.31). Surgical time was 132.2 minutes (±37.17), with an estimated blood loss and ischemia time of 103.63 mL (±65.92) and 16.72 minutes (±9.52), respectively. One patient had postoperative bleeding that was resolved without transfusion. The median hospitalization period was 3.9 d (±0.53). Loss of intra-abdominal pressure was not observed, and pressure was stable at 10 mm Hg.Conclusion:The AirSeal System and its valveless trocar eliminated the need for an additional port placement in our series. The technique is feasible, safe, and reproducible; therefore, it may be implemented in selected cases of robot-assisted partial nephrectomies.     

Ultra-Violet Light Emission from HPV-G Cells Irradiated with Low Let Radiation From 90Y; Consequences for Radiation Induced Bystander Effects

In this study, we aimed to establish the emission of UV photons when HPV-G cells and associated materials (such as the cell substrate and cell growth media) are exposed to low LET radiation. The potential role of UV photons in the secondary triggering of biological processes led us to hypothesize that the emission and absorption of photons at this wavelength explain some radiation induced “bystander effects” that have previously been thought to be chemically mediated. Cells were plated in Petri-dishes of two different sizes, having different thicknesses of polystyrene (PS) substrate, and were exposed to β-radiation from ⁹⁰Y produced by the McMaster Nuclear Reactor. UV measurements were performed using a single photon counting system employing an interference-type filter for selection of a narrow wavelength range, 340±5 nm, of photons. Exposure of the cell substrates (which were made of polystyrene) determined that UV photons were being emitted as a consequence of β particle irradiation of the Petri-dishes. For a tightly collimated β-particle beam exposure, we observed 167 photons in the detector per unit μCi in the shielded source for a 1.76 mm thick substrate and 158 photons/μCi for a 0.878 mm thick substrate. A unit μCi source activity was equivalent to an exposure to the substrate of 18 β-particles/cm² in this case. The presence of cells and medium in a Petri-dish was found to significantly increase (up to a maximum of 250%) the measured number of photons in a narrow band of wavelengths of 340±5 nm (i.e. UVA) as compared to the signal from an empty control Petri-dish. When coloured growth medium was added to the cells, it reduced the measured count rate, while the addition of transparent medium in equal volume increased the count rate, compared to cells alone. We attribute this to the fact that emission, scattering and absorption of light by cells and media are all variables in the experiment. Under collimated irradiation conditions, it was observed that increasing cell density in medium of fixed volume resulted in a decrease in the observed light output. This followed a roughly exponential decline. We suggest that this may be due to increased scattering at the cell boundary and absorption of the UV in the cells. We conclude that we have measured UVA emitted by cells, cell medium and cell substrates as a consequence of their irradiation by low LET β-particle radiation. We suggest that these secondary UV photons could lead to effects in non-targetted cells. Some effects that had previously been attributed to a chemically mediated “bystander effect” may in fact be due to secondary UV emission. Some radiation bystander effect studies may require re-interpretation as this phenomenon of UV emission is further investigated.     

Perioperative Antibiotikaprophylaxe in der MKG-Chirurgie

The use of antibiotic prophylaxis in oral and maxillofacial surgery depends on the type of surgery, the duration of the operation and the local and systemic infection risks of the patient. A higher risk of infection exists if the operating field is contaminated or infected and if there are more patient-specific and surgery-specific risk factors. The aim of antibiotic prophylaxis with a systemic antibiotic is protection of the patient from postoperative wound infections.