A 5-year review of teeth filled with the noninstrumentation technology.

AIM: The aim of this Case Series was to evaluate the radiographic quality of root fillings performed 5 years previously using the noninstrumentation technology (NIT)-obturation method and to assess radiographically the outcome of these root canal treatments. METHODOLOGY: Seventeen patients requiring root canal treatment participated in this study and were re-evaluated after 5 years. After instrumentation with K-Flexofiles, Calcium-Hydroxide inter-appointment dressing, re-entry and copious irrigation with NaOCl, the teeth were root filled using the NIT. RESULTS: Immediately after obturation the root fillings were (-0.78 +/- 0.11 mm) short when taking the radiographic apex as a reference point. After 60 months these values were -0.85 +/- 0.11 mm. No statistical difference was found (P > 0.05). In the periapical region, PAI rating 1 and 2 increased from 20.1% to 75.6% after 60 months. CONCLUSIONS: * This prospective Case Series demonstrated the performance of the NIT-obturation method in vivo. * Root canals filled by the reduced-pressure method using sealer combined with gutta-percha cones showed good radiographic quality. * Periapical healing after 5 years was comparable with conventional filling techniques.

In vivo performance of the new non-instrumentation technology (NIT) for root canal obturation.

AIM: The aim of this in vivo study was to compare the radiographic quality of root fillings performed by the NIT-obturation method versus conventional mechanical obturation. METHODOLOGY: Sixty-six patients needing root canal treatment participated in this study. The treatments were performed by three private practitioners. The root canals were instrumented with K-Flexofiles to a master apical file between sizes 25 and 60, followed by step-back flaring up to size 70. Copious irrigation was used throughout the instrumentation procedure with NaOCl (3%). The teeth were obturated either by lateral condensation, the McSpadden technique (control) or by the new non-instrumentation technology (NIT) with and without using gutta-percha points. In the NIT method, a low pressure was created within the tooth, and AH 26 sealer was sucked into the root canal system. Radiographs of the root-filled teeth were analysed and the length of the root filling, the presence of voids and the area of any other fillings determined. RESULTS: The root canal fillings of the control group (0.1 +/- 0.1 mm) and those of the NIT/gutta-percha group (0.3 +/- 0.1 mm) were both overextended when taking the apical constriction as a reference point. Root canal fillings of the NIT/gutta-percha group were statistically (P < 0.05) significantly longer than those of the NIT without gutta-percha group. The latter showed slightly underextended root canal fillings (-0.14 +/- 0.1 mm). CONCLUSIONS: The present investigation demonstrated the performance of the NIT-obturation method in vivo. Root canals filled by the reduced-pressure-method using sealer combined with gutta-percha cones exhibited equivalent radiographic quality compared to conventionally filled canals.

Comparison of two devices for root canal cleansing by the noninstrumentation technology.

Optimal cleansing of the root canal system is a prime prerequisite for long-term success in endodontics. Recently, a new method and device were presented providing "automatic" root canal cleansing without the need of endodontic instrumentation. Cleanliness results equivalent to or better than those with conventional methods were achieved in considerably less time. The purpose of the present study was 2-fold: (a) optimization of the device to make it applicable to patients and (b) to measure its effectiveness against the predecessor model. A total of 156 root canals of 66 freshly extracted vital human molars were cleansed with the new device and their cleanliness compared with that of 149 canals of 52 molars cleansed previously with the first apparatus. Data indicated that the smaller new machine produced equivalent or better cleanliness results in the root canal system using significantly less irrigant (NaOCl).

Erosion on abraded dental hard tissues by acid lozenges: an in situ study.

The aim of this study was to analyse the erosive effect of acidic lozenges and to compare it with that of orange juice, known to have the capacity to cause erosion. Two acidic, sugar-free lozenges and orange juice were tested in situ in nine patients. Changes in surface Knoop microhardness and change in the surface texture were assessed. The results revealed that orange juice and one acidic lozenge were--under the conditions of this experiment--capable of significantly softening abraded enamel (P < or = 0.017). It was concluded that excessive consumption of acidic lozenges could have the potential to enhance existing dental erosion.

Condensation pressure during amalgam placement in patients.

The purpose of this study was to investigate the condensation pressure during amalgam placement in patients. Forty-four practitioners were asked to fill two class 2 cavities in the lower jaw on their patients in their own practice with the aid of a force-measuring plugger. This device, with semiconductor strain gauges, allowed the dentist to have an identical tactile feedback as with any other plugger. Three different amalgams, with different shapes of alloy particles, were tested. The results showed a maximum condensation pressure of 8.9+/-2.4 MPa and 5.5+/-1.8 MPa with a small and a large amalgam plugger, respectively. Average condensation pressures were 3.7+/-1.3 MPa for the small and 2.2+/-0.9 MPa for the large instrument. The total working time required to fill a cavity was on average 131 s; the amalgam was effectively condensed for 44 s. No significant differences between amalgams with different shapes of alloy particles, no influence of time of day, and no difference between female and male dentists were found. This study showed that the condensation pressure is lower than often recommended, and that it is not statistically different from the values obtained in a previous laboratory study.

A comparison between a new vacuum obturation technique and lateral condensation: an in vitro study.

A new machine that allows cleaning root canals without conventional instruments has been introduced. Because this noninstrumented technique does not enlarge the root canal system, a new device had to be developed to fill the root canal system. The new machine was able to produce a vacuum that allowed proper drying and filling of a root canal system. This study evaluated the new vacuum filling method and compared it with lateral condensation. Canals of 40 extracted human molars, instrumented using the step-back technique, were either filled with the new vacuum obturation technique using AH26 sealer and a gutta-percha single cone or by lateral condensation. Teeth were coated with wax and placed into India ink for 7 days. The wax was then removed and the teeth were cleared. All teeth were evaluated for linear dye penetration using a x20 viewer. Obturation with the new vacuum technique resulted in significantly less leakage than lateral condensation.

Isolation and characterization of four basic proteins from horse eosinophilic granules.

Four new basic proteins were isolated from horse eosinophils and purified. The eosinophils release these proteins after permeabilization with saponin and degranulation stimulized by guanosine 5'-O-thiotriphosphate. The proteins were separated and purified on a Superose P12- and a Mono S-column by fast protein liquid chromatography. The amino acid composition, the relative molecular mass, the isoelectric point and the partial N-terminal sequence of the four proteins were determined. Papain-activation and ribonuclease activity of the four proteins were tested for comparison with the human eosinophil basic granular proteins. The cytotoxicity of the hole granular extract and of the isolated basic proteins against Escherichia coli K12 was also studied.

Relation between intestinal alkaline phosphatase activity and brush border membrane transport of inorganic phosphate, D-glucose, and D-glucose-6-phosphate.

In order to evaluate the role of the alkaline phosphatase in intestinal transport processes, we studied the influence of known modulators of the alkaline phosphatase (polyclonal anti-calf AP antibodies, theophylline and zinc ions) on the absorption rate of glucose, inorganic phosphate and glucose liberated from glucose-6-phosphate into calf duodenal brush border membrane vesicles. Our results allow the following conclusions: First a direct involvement of the AP in the Na+-dependent glucose absorption is unlikely. Indeed, theophylline inhibits strongly the AP activity but rather stimulates the glucose uptake; second the AP is indirectly involved in glucose absorption from glucose-6-phosphate, if its enzymatic hydrolysis is the only source of glucose. In that case the Na+-dependent uptake of glucose was completely suppressed either by phosphatase specific antibodies or by theophylline; third the positive correlation found with calf intestinal BBMV between the inhibition of AP by AP antibodies or by theophylline and the decrease of rate of Na+-dependent Pi uptake rate suggests that the enzyme plays some role in the Pi absorption. It appears from the present study that the AP is probably not a carrier protein itself, but its hydrolytic activity might nevertheless be important for intestinal absorption. After hydrolysis of phosphoric esters the alcohol residues and Pi can be supplied to their specific carriers. Furthermore, the high Pi affinity of the enzyme at physiological pH values, could even favour a transient sequestration of phosphate, which then could be transferred to the Pi carrier.

An improved method for the isolation of eosinophilic leukocytes from normal human blood.

A relatively short and simple method for the isolation of the eosinophils from normal human blood is reported. With a recovery of about 45-55%, cell preparations, showing a degree of purity of 90-98%, are obtained. The isolated cells are morphologically intact and viable, as assessed by the trypan blue exclusion test and by active phagocytosis.

A rapid and simple method for the isolation of pure eosinophilic leukocytes from horse blood.

An improved and short method is described for the isolation of intact eosinophilic leukocytes from horse blood with high yield (1--1.5 g/20 l). Viability and purity of the preparations were verified by light and electron microscopy and by the trypan blue exclusion test. Isolated eosinophils were 98--100% pure, intact and viable, and they could be shown to phagocytise immune-complexes.