Evaluation of Primary Stability of Self‐Tapping and Non‐Self‐Tapping Dental Implants. A 12‐Week Clinical Study

Purpose: The aim of this study was to investigate the relationship between surgical techniques and implant macro‐design (self‐tapping/non‐self‐tapping) for the optimization of implant stability in the low‐density bone present in the posterior maxilla using resonance frequency analysis (RFA). Materials and Methods: A total of 102 implants were studied. Fifty‐six self‐tapping BlueSkyBredent® (Bredent GmbH&Co.Kg®, Senden, Germany) and 56 non‐self‐tapping Standard Plus Straumann® (Institut Straumann AG®, Waldenburg, Switzerland) were placed in the posterior segment of the maxilla. Implants of both types were placed in sites prepared with either lateral bone‐condensing or with bone‐drilling techniques. Implant stability measurements were performed using RFA immediately after implant placement and weekly during a 12‐week follow‐up period. Results: Both types of implants placed after bone condensing achieved significantly higher stability immediately after surgery, as well as during the entire 12‐week observation period compared with those placed following bone drilling. After bone condensation, there were no significant differences in primary stability or in implant stability after the first week between both implant types. From 2 to 12 postoperative weeks, significantly higher stability was shown by self‐tapping implants. After bone drilling, self‐tapping implants achieved significantly higher stability than non‐self‐tapping implants during the entire follow‐up period. Conclusions: The outcomes of the present study indicate that bone drilling is not an effective technique for improving implant stability and, following this technique, the use of self‐tapping implants is highly recommended. Implant stability optimization in the soft bone can be achieved by lateral bone‐condensing technique, regardless of implant macro‐design.     

Slow Resorption of Anorganic Bovine Bone by Osteoclasts in Maxillary Sinus Augmentation

Purpose: Different biomaterials have been suggested for guided bone regeneration (GBR). These might show the ideal properties to let a new bone formation in the grafted area. Among these ideal features, it is essential their controlled resorption in order to be replaced for new vital bone. Bovine bone has been used widely as a good biomaterial for GBR, however there is still an interesting controversy about its resorbable capacity. In this sense, the objective of this study was to examine the behavior of anorganic bovine bone (ABB) in long‐term maxillary sinus graft healing and study its relationship with morphological and morphometrical variables. Materials and Methods: Seventeen maxillary sinus augmentation procedures were performed in patients. Bone cores were obtained from implant receptor sites at 6 months, 3 years, and 7 years of implant placement for histological, morphometric, and immunohistochemical (tartrate resistant acid phosphatase [TRAP]/cathepsin K/CD68) studies. Results: The percentages of bone, ABB particles, connective tissue, osteocytes, and osteoblasts in maxillary sinus grafts were similar at 6 months, 3 years, and 7 years. A progressive and significant decrease was detected in osteoclasts (p = .05, Kruskal‐Wallis test), TRAP and cathepsin K expression (p = .014 and p = .021, respectively), and osteoid lines (p = .038). Conclusion: According to these data, a decrease in osteoclasts over time may, partially, explain the ABB persistence observed in core biopsies. Further studies with more cases and different graft maturation times are required to elucidate the resorption rates and cell events underlying these phenomena.     

Biomechanical and Bone Histomorphological Evaluation of Two Surfaces on Tapered and Cylindrical Root Form Implants: An Experimental Study in Dogs

Purpose: The aim of this study was to evaluate the early bone response of tapered and cylindrical root form implants with two different surface treatments in fresh extraction sockets after 4 and 8 weeks. Materials and Methods: Surface treatments and implant design comprised (n = 9 each): tapered with dual acid‐etched surface; tapered with dual acid‐etched and sandblasted surface (T DAE SB); cylindrical with dual acid‐etched surface (C DAE); and cylindrical with dual acid‐etched and sandblasted surface (C DAE SB). Implants were placed in the distal sockets of mandibular premolars (₂P_2,3P_3,4P₄) of six beagle dogs, remaining in vivo for 4 and 8 weeks. After sacrifice, the implants were subjected to torque to the point of interface fracture and subsequently nondecalcified for histomorphological study. Statistical analysis was performed by a General Linear Model (GLM) analysis of variance model with a significance level of 5%. Results: Torque to interface fracture was significantly greater for the C DAE SB group than for the other groups (p < .001). Histomorphological analysis showed woven bone formation around all implant surfaces at 4 weeks and its replacement by lamellar bone at 8 weeks. Study time (4 or 8 weeks) did not affect torque measures. Conclusions: The double acid‐etched and sandblasted sample surface increased early bone biomechanical fixation of both cylindrical and tapered root form implants. The cylindrical root form implants showed higher torque to interface fracture values when compared with the tapered root form implants. The C DAE SB surface group showed the highest biomechanical fixation values (p < .001).     

State of the art: new developments in cardiac imaging

Cardiac imaging continues to reveal new anatomical and functional insights into heart disease. In echocardiography, both transesophageal and transthoracic three-dimensional imaging have been fully developed and optimized, and the value of the techniques that have increased our understanding of cardiac mechanics and ventricular function is well established. At the same time, the healthcare industry has released new devices onto the market which, although they are easier to use, have limitations that restrict their use for routine assessment. Tomography's diagnostic and prognostic value in coronary artery disease continues to increase while radiation exposure becomes progressively lower. With cardiac magnetic resonance imaging, myocardial injury and recovery in ischemic heart disease and following acute coronary syndrome can be monitored in exquisite detail. The emergence of new combined tomographic and gamma camera techniques, exclusively developed for nuclear cardiology, have improved the quality of investigations and reduced radiation exposure. The hybrid or fusion images produced by combining different techniques, such as nuclear cardiology techniques and tomography, promise an exciting future.     

Repeat versus primary slings in patients with intrinsic sphincter deficiency

Introduction and hypothesis

Our goal was to compare outcomes of repeat vs. primary synthetic slings in patients with stress urinary incontinence (SUI) with intrinsic sphincter deficiency (ISD).

Materials and methods

We reviewed patients who underwent a sling for SUI with ISD from 2003 to 2010. The patients were divided into two groups according to whether they underwent primary or repeat sling. Surgical success was defined as no incontinence and no reintervention (i.e., urethral bulking) during follow-up. Statistical analysis included the unpaired t test, Wilcoxon rank sums test, chi-squared/Fisher’s exact tests, and logistic regression to identify risk factors associated with failure.

Results

Six hundred and thirty-seven patients with ISD underwent a sling procedure at our institution; 557 (87 %) a primary sling and 80 (13 %) a repeat sling. Patient demographics were similar. Preoperatively, patients with recurrent SUI reported more subjective bother. Mean follow-up was 66.5 weeks (24–374). Success was achieved in 81 % of primary compared with 55 % of repeat slings (p?<?0.0001). Repeat patients were 3.4 times more likely to fail surgery [odds ratio (OR)?=?3.43, 95 % confidence interval (CI) 2.1–5.6]. Additionally 30 % of the repeat group underwent urethral bulking postoperatively compared with 8.6 % in the primary group (OR?=?4.4, 95 % CI 2.5–7.7). Prior incontinence procedures, a positive supine stress test, and transobturator sling were independent risk factors for failure. Among the types of slings placed (transobturator, retropubic, tensioned pubovaginal), pubovaginal slings were most successful (OR?=?2.7, 95 % CI 1.4–5.2).

Conclusion

In women with ISD, repeat slings are associated with lower success rates compared with primary slings. Pubovaginal slings resulted in the highest success rate compared with both transobturator and retropubic slings.