Influence of a machined collar on crestal bone changes around titanium implants: a histometric study in the canine mandible

It has been shown that peri-implant crestal bone reactions are influenced by both a rough-smooth implant border in one-piece, non-submerged, as well as an interface (microgap [MG] between implant/abutment) in two-piece butt-joint, submerged and non-submerged implants being placed at different levels in relation to the crest of the bone. According to standard surgical procedures, the rough-smooth implant border for implants with a smooth collar should be aligned with the crest of the bone exhibiting a smooth collar adjacent to peri-implant soft tissues. No data, however, are available for implants exhibiting a sandblasted, large-grit and acid-etched (SLA) surface all the way to the top of a non-submerged implant. Thus, the purpose of this study is to histometrically examine crestal bone changes around machined versus SLA-surfaced implant collars in a side-by-side comparison.

Is a grooved collar implant design superior to a machined design regarding bone level alteration? An observational pilot study.

OBJECTIVE This retrospective observational pilot study examined differences in peri-implant bone level changes (ΔIBL) between two similar implant types differing only in the surface texture of the neck. The hypothesis tested was that ΔIBL would be greater with machined-neck implants than with groovedneck implants. METHOD AND MATERIALS 40 patients were enrolled; n = 20 implants with machined (group 1) and n = 20 implants with a rough, grooved neck (group 2), all placed in the posterior mandible. Radiographs were obtained after loading (at 3 to 9 months) and at 12 to 18 months after implant insertion. Case number calculation with respect to ΔIBL was conducted. Groups were compared using a Brunner-Langer model, the Mann-Whitney test, the Wilcoxon signed rank test, and linear model analysis. RESULTS After the 12- to 18-month observation period, mean ΔIBL was -1.11 ± 0.92 mm in group 1 and -1.25 ± 1.23 mm in group 2. ΔIBL depended significantly on time (P < .001), but not on group. In both groups, mean marginal ΔIBL was significantly less than -1.5 mm. Only insertion depth had a significant influence on the amount of periimplant bone loss (P = .013). Case number estimate testing for a difference between group 1 and 2 with a power of 90% revealed a sample size per group of 1,032 subjects. CONCLUSION ΔIBL values indicated that both implant designs fulfilled implant success criteria, and the modification of implant neck texture had no significant influence on ΔIBL.

I think of my family, therefore I am: perceptions of daily occupations of some Albanians in Switzerland

The purpose of this qualitative study was to increase the understanding of the relationship between culture and occupation by exploring the perceptions of current daily occupations of some immigrants living in Switzerland. Semi-structured interviews with eight healthy Muslim Albanian men doing blue-collar work were analysed in a comparative manner followed by an interpretation. Three themes were identified: "Everything I do I do for my family"; "Where do I belong?"; and "Doing something for myself". These themes reflect the occupational perceptions of the participants. The findings are discussed in relation to the ongoing discourses on individualism and collectivism. To offer occupational therapy appropriately to a multicultural clientele the findings indicate the necessity to be conscious of the differences between one's own and the client's attitudes regarding individualism and collectivism.

Open or submerged healing of implants with platform switching: a randomized, controlled clinical trial

The temporal pattern of bone-level alterations in conventionally restored implants is dependent upon healing mode (open or submerged). This study examined the influence of healing on marginal bone levels at implants with a medium-rough surface including the implant collar and a clearance-fit implant-abutment connection restored according to a platform-switching concept.

Effects of implant design on marginal bone changes around early loaded, chemically modified, sandblasted Acid-etched-surfaced implants: a histologic analysis in dogs

A minimal marginal bone loss around implants during early healing has been considered acceptable. However, the preservation of the marginal bone is related to soft tissue stability and esthetics. Implant designs and surfaces were evaluated to determine their impact on the behavior of the crestal bone. The purpose of this study is to evaluate histologic marginal bone level changes around early loaded, chemically modified, sandblasted acid-etched-surfaced implants with a machined collar (MC) or no MC (NMC).

Clinical field trial examining an implant with a sand-blasted, acid-etched surface

BACKGROUND: Conventionally, endosseous dental implants have required 3 to 6 months of uninterrupted healing based on observations for dental implants that were characterized by a relatively smooth machined surface. Many studies have since demonstrated that implants with a roughened surface resulted in greater bone apposition, earlier bone contact, and a stronger bond between the implant and the bone, suggesting that implants with roughened surfaces could be loaded earlier than 3 to 6 months. Formal clinical studies confirmed that implants with rough surfaces can have abutments placed and be loaded occlusally as early as 6 weeks postplacement. The purpose of this prospective, human clinical investigation was to evaluate a large number of implants with a specific rough surface (sand-blasted acid-etched [SLA]) placed in everyday practice under routine private-practice conditions. METHODS: A prospective, multicenter, human clinical observational study was initiated with the goal of recruiting a minimum of 500 patients and 800 implants. The implants were to be placed and restored in predominantly private-practice settings around the world. Ninety-two practitioners in 16 countries agreed to participate, and 86 followed the study design. Patients had to be in good health, have sufficient bone to encase the implant, and agree to return for recall appointments. Exclusion criteria included heavy smoking (>10 cigarettes a day) and bone augmentation procedures at the implant site. All implants were two-piece (an abutment was to be placed after 6 weeks of healing) and were characterized by the presence of a transmucosal polished collar. Each implant had an SLA surface. All implants were positioned using a non-submerged (single-stage) surgical technique. Survival and success rates were calculated by life-table analyses. RESULTS: A total of 706 patients were enrolled and 1,406 implants were placed. In the final analyses, 590 patients with 990 implants (70.4% of those enrolled) met all inclusion criteria, including placement of an abutment and provisional restoration within 63 days of surgical placement. The majority of implants were 10 and 12 mm long (78.7%) and were placed in type II and III bone (87%). Seventy-three percent of the implants were placed in the mandible, and 27% were placed in the maxilla. The cumulative survival rate was 99.56% at 3 years and 99.26% at 5 years. The overall success rate was 99.12% at 3 years and 97.38% after 5 years. CONCLUSIONS: Under private-practice conditions, implants with an SLA surface could be placed and restored predictably within 6 to 8 weeks. Data from this prospective, multicenter, human observational study reinforced the results of more formal clinical studies and demonstrated that implants with the SLA surface can be restored in patients in approximately half of the time of conventional healing periods.

Crossover comparison of the laryngeal mask supreme and the i-gel in simulated difficult airway scenario in anesthetized patients

BACKGROUND: The single-use supraglottic airway devices LMA-Supreme (LMA-S; Laryngeal Mask Company, Henley-on-Thames, United Kingdom) and i-gel (Intersurgical Ltd, Wokingham, Berkshire, United Kingdom) have a second tube for gastric tube insertion. Only the LMA-S has an inflatable cuff. They have the same clinical indications and might be useful for difficult airway management. This prospective, crossover, randomized controlled trial was performed in a simulated difficult airway scenario using an extrication collar limiting mouth opening and neck movement. METHODS: Sixty patients were included. Both devices were placed in random order in each patient. Primary outcome was overall success rate. Other measurements were time to successful ventilation, airway leak pressure, fiberoptic glottic view, and adverse events. RESULTS: Success rate for the LMA-S was 95% versus 93% for the i-gel (P = 1.000). LMA-S needed shorter insertion time (34 +/- 12 s vs. 42 +/- 23 s, P = 0.024). Tidal volumes and airway leak pressure were similar (LMA-S 26 +/- 8 cm H20; i-gel 27 +/- 9 cm H20; P = 0.441). Fiberoptic view through the i-gel showed less epiglottic downfolding. Overall agreement in insertion outcome was 54 (successes) and 1 (failure) or 55 (92%) of 60 patients. The difference in success rate was 1.7% (95% CI -11.3% to 7.6%). CONCLUSIONS: Both airway devices had similar insertion success and clinical performance in the simulated difficult airway situation. The authors found less epiglottic downfolding and better fiberoptic view but longer insertion time with the i-gel. Our study shows that both devices are feasible for emergency airway management in patients with reduced neck movement and limited mouth opening.

Cement-augmented anterior screw fixation of Type II odontoid fractures in elderly patients with osteoporosis

BACKGROUND CONTEXT: Closed reduction and internal fixation by an anterior approach is an established option for operative treatment of displaced Type II odontoid fractures. In elderly patients, however, inadequate screw purchase in osteoporotic bone can result in severe procedure-related complications. PURPOSE: To improve the stability of odontoid fracture screw fixation in the elderly using a new technique that includes injection of polymethylmethacrylat (PMMA) cement into the C2 body. STUDY DESIGN: Retrospective review of hospital and outpatient records as well as radiographs of elderly patients treated in a university hospital department of orthopedic surgery. PATIENT SAMPLE: Twenty-four elderly patients (8 males and 16 females; mean age, 81 years; range, 62-98 years) with Type II fractures of the dens. OUTCOME MEASURES: Complications, cement leakage (symptomatic/asymptomatic), operation time, loss of reduction, pseudarthrosis and revision surgery, patient complaints, return to normal activities, and signs of neurologic complications were all documented. METHODS: After closed reduction and anterior approach to the inferior border of C2, a guide wire is advanced to the tip of the odontoid under biplanar fluoroscopic control. Before the insertion of one cannulated, self-drilling, short thread screws, a 12 gauge Yamshidi cannula is inserted from anterior and 1 to 3 mL of high-viscosity PMMA cement is injected into the anteroinferior portion of the C2 body. During polymerization of the cement, the screws are further inserted using a lag-screw compression technique. The cervical spine then is immobilized with a soft collar for 8 weeks postoperatively. RESULTS: Anatomical reduction of the dens was achieved in all 24 patients. Mean operative time was 64 minutes (40-90 minutes). Early loss of reduction occurred in three patients, but revision surgery was indicated in only one patient 2 days after primary surgery. One patient died within the first eight postoperative weeks, one within 3 months after surgery. In five patients, asymptomatic cement leakage was observed (into the C1-C2 joint in three patients, into the fracture in two). Conventional radiologic follow-up at 2 and 6 months confirmed anatomical healing in 16 of the19 patients with complete follow-up. In two patients, the fractures healed in slight dorsal angulation; one patient developed a asymptomatic pseudarthrosis. All patients were able to resume their pretrauma level of activity. CONCLUSIONS: Cement augmentation of the screw in Type II odontoid fractures in elderly patients is technically feasible in a clinical setting with a low complication rate. This technique may improve screw purchase, especially in the osteoporotic C2 body.