Over‐the‐scope clip system: A review of 1517 cases over 9 years

Rescue therapy for gastrointestinal (GI) refractory bleeding, perforation, and fistula has traditionally required surgical interventions owing to the limited performance of conventional endoscopic instruments and techniques. An innovative clipping system, the over‐the‐scope clip (OTSC), may play an important role in rescue therapy. This innovative device is proposed as the final option in endoscopic treatment. The device presents several advantages including having a powerful sewing force for closure of GI defects using a simple mechanism and also having an innovative feature, whereby a large defect and fistula can be sealed using accessory forceps. Consequently, it is able to provide outstanding clinical effects for rescue therapy. This review clarifies the current status and limitations of OTSC according to different indications of GI refractory disease, including refractory bleeding, perforation, fistula, and anastomotic dehiscence. An extensive literature search identified studies reported 10 or more cases in which the OTSC system was applied. A total of 1517 cases described in 30 articles between 2010 and 2018 were retrieved. The clinical success rates and complications were calculated overall and for each indication. The average clinical success rate was 78% (n = 1517) overall, 85% for bleeding (n = 559), 85% (n = 351) for perforation, 52% (n = 388) for fistula, 66% (n = 97) for anastomotic dehiscence, and 95% (n = 122) for other conditions, respectively. The overall and severe OTSC‐associated complications were 1.7% (n = 23) and 0.59% (n = 9), respectively. This review concludes that the OTSC system may serve as a safe and productive device for GI refractory diseases, albeit with limited success for fistula.     

Influence of phase transformation on the torsional and bending properties of nickel-titanium rotary endodontic instruments

AIM: To investigate the relationship between the functional properties and the phase transformation of nickel-titanium endodontic instruments. METHODOLOGY: Five types of rotary nickel-titanium endodontic instruments with a 0.30 mm diameter tip (EndoWave, HERO 642, K3, ProFile.06, and ProTaper) were selected to investigate torsional and bending properties, and phase transformation behaviour. A torsional test was performed according to ISO publication 3630-1, and maximum torque and angular deflection at fracture were measured. Bending load of the instruments was measured in a cantilever-bending test at 37 degrees C with the maximum deflection of 4.0 mm. A stainless steel K-file was used for reference. Phase transformation behaviour was measured by differential scanning calorimetry (DSC). From the DSC curve, transformation temperatures were calculated. Data were analysed by anova and the Tukey-Kramer's test. RESULTS: The maximum torsional torque values of HERO, K3 and ProTaper were significantly higher (P < 0.05) than those of EndoWave, ProFile and K-file. The K-files had the lowest torque value. Angular deflection at fracture was significantly higher (P < 0.05) for K-files than that for any nickel-titanium instrument. The bending load values of HERO and K3 were significantly higher (P < 0.05) than those of EndoWave, ProFile, ProTaper and K-file. The K-files had the lowest load value, although residual deflection remained. The transformation temperatures of HERO and K3 were significantly lower (P < 0.05) than those of EndoWave, ProFile and ProTaper. CONCLUSIONS: The functional properties of nickel-titanium endodontic instruments, especially their flexible bending load level, were closely related to the transformation behaviour of the alloys.     

Deformation properties of Ti-6A1-7Nb alloy castings for removable partial denture frameworks

Ti-6Al-7Nb alloy was cast into three differently designed, removable partial denture frameworks: Palatal strap (PS), Anterior-posterior bar (AP), and Horseshoe-shaped bar (HS). The vertical displacement and local strain of Ti-6Al-7Nb alloy frameworks were investigated to compare against those of Co-Cr alloy frameworks. Vertical loading force of 19.6 N was applied at two locations, 10 and 20 mm, from the distal end of the framework. Although higher vertical displacement and local strain were observed for Ti-6Al-7Nb alloy frameworks than those for Co-Cr alloy frameworks, the PS framework appeared to show the least deformation. In addition, the strain at 10-mm location was higher than that at 20-mm location for AP and HS frameworks. This study thus proved that design had a significant influence on the deformation properties of denture frameworks. The PS design was evaluated to be a suitable design for the removable denture framework with Ti-6Al-7Nb alloy.     

Castability of Ti-6Al-7Nb alloy for dental casting

Castability of Ti-6Al-7Nb alloy, CP Ti, and Co-Cr alloy was examined for mesh type and plate type specimens. The casting was carried out with a pressure type casting machine and commercial molding material. The castability of the mesh type specimen was evaluated in terms of the number of cast segments (castability index), and that of the plate type was evaluated by the area of the specimen (casting rate). X-ray images processed by a digital imaging technique were used to identify the casting porosity. The casting rate of the specimens increased with increasing thickness of the specimens. It was concluded that the castability index and the casting rate of Ti-6Al-7Nb alloy was slightly lower than that of CP Ti, and higher than that of Co-Cr alloy, were as Ti-6Al-7Nb alloy showed fewer casting porosities than CP Ti and smaller ones than Co-Cr alloy, which was advantageous for increasing the reliability of the casting properties.     

Professional oral health care reduces the number of oropharyngeal bacteria

Silent aspiration of oropharyngeal pathogenic organisms is a significant risk factor causing pneumonia in the elderly. We hypothesized that regular oral hygiene care will affect the presence of oropharyngeal bacteria. Professional cleaning of the oral cavity and/or the gargling of a disinfectant liquid solution was performed over a five-month period in three facilities for the dependent elderly. Total oropharyngeal bacteria, streptococci, staphylococci, Candida, Pseudomonas, and black-pigmented Bacteroides species were monitored. The levels of these oropharyngeal bacteria decreased or disappeared after weekly professional oral health care, i.e., cleaning of teeth, dentures, tongue, and oral mucous membrane by dental hygienists. After lunch, gargling with povidone iodine was shown to be less effective than professional oral care. These findings indicate that weekly professional mechanical cleaning of the oral cavity, rather than a daily chemical disinfection of the mouth, can be an important strategy to prevent aspiration pneumonia in the dependent elderly.