Automatic processing: effects of temperature and time changes on sensitometric properties of ULTRA-SPEED and EKTASPEED films

Effects of developer depletion on image quality of Kodak Insight and Ektaspeed Plus films

OBJECTIVE

To evaluate the effect of processing solution depletion on the image quality of F-speed dental X-ray film (Insight), compared with Ektaspeed Plus.

METHODS

The films were exposed with a phantom and developed in manual and automatic conditions, in fresh and progressively depleted solutions. The comparison was based on densitometric analysis and subjective appraisal.

RESULTS

The processing solution depletion presented a different behaviour depending on whether manual or automatic technique was used. The films were distinctly affected by depleted processing solutions.

CONCLUSIONS

The developer depletion was faster in automatic than manual conditions. Insight film was more resistant than Ektaspeed Plus to the effects of processing solution depletion. In the present study there was agreement between the objective and subjective appraisals.

The effect of automated nonroller processing on the sensitometric characteristics of 3 intraoral film types

OBJECTIVES

We sought to compare the sensitometric characteristics of 3 intraoral film types processed in an automated roller solution with the characteristics of the films processed in 4 automated nonroller solutions.

STUDY DESIGN

Eastman Kodak Ultra-Speed, Flow X-ray EV-57, and Eastman Kodak InSight films were exposed to varying levels of radiation and processed in 1 automated roller solution and in 4 nonroller solutions. Speed and contrast were measured at various density levels and ranges.

RESULTS

With the exception of 1 nonroller solution, there was little difference in speed between roller and nonroller processing chemicals at various density levels. Some nonroller solutions were faster than the roller chemicals for all films. Nonroller processing mostly increased contrast compared with roller processing over various ranges.

CONCLUSIONS

Sensitometric properties of films processed in automatic nonroller solutions are comparable in many cases to those in roller solutions, sometimes resulting in greater speed and contrast. Different adjustments in exposure factors are required for specific film/processing combinations.

A comparison of Kodak Ultraspeed and Ektaspeed Plus dental X-ray films for use in endodontics

BACKGROUND

The advantage of using a faster film for length determination in endodontic therapy is obvious. However, for such a film to be generally accepted, it must demonstrate comparable diagnostic quality to traditionally used films.

METHODS

The comparative accuracy of canal length determination of Ultraspeed and Ektaspeed Plus dental X-ray films was assessed in maxillary first and second molars; for different canals, for different teeth, for different exposures, and for different examiners (five general dentists and three endodontic specialists).

RESULTS

In general, there were no significant differences between films, among examiners, or any interaction between films and exposures. That is, an assessor's ability to estimate lengths was not significantly influenced by the film type or by exposure used. There was a wide divergence in the individual assessor's ability to estimate lengths. Specialists estimated lengths more accurately than general practitioners and estimated lengths more accurately with Ektaspeed Plus film. Length determination in distobuccal and mesiobuccal canals was more accurate than in palatal canals. Most palatal canals were underestimated in length by more than 1mm. The use of file sizes larger in number than size 15 is recommended in these canals.

CONCLUSION

For length determination, Ektaspeed Plus dental X-ray film is as effective as Ultraspeed film. Given the acceptable quality and accuracy of Ektaspeed Plus film, there seems to be no clinical reason to subject patients to greater radiation by using a slower film during endodontic therapy.

Characteristics of Kodak Insight, an F-speed intraoral film

OBJECTIVES

This study reports film speed, contrast, exposure latitude, resolution, and response to processing solution depletion of Kodak Insight intraoral film.

METHODS

Densitometric curves were generated by using International Standards Organization protocol. Additional curves were generated for Ultra-speed, Ektaspeed Plus, and Insight films developed in progressively depleted processing solutions. Eight observers viewed images of a resolution test tool for maximum resolution assessment. Images of an aluminum step-wedge were reviewed to determine useful exposure latitude.

RESULTS

Insight's sensitivity in fresh automatic processor solutions places it in the F-speed group. An average gradient of 1.8 was found with all film types. Insight provided 93% of the useful exposure latitude of Ektaspeed Plus film. Insight maintained contrast in progressively depleted processing solutions. Like Ektaspeed Plus, Insight was able to resolve at least 20 line-pairs per millimeter.

CONCLUSIONS

Under International Standards Organization conditions, Insight required only 77% of the exposure of Ektaspeed Plus film. Insight film provided stable contrast in depleted processing solutions.

Influence of developer exhaustion on accuracy of quantitative digital subtraction radiography: an in vitro study

OBJECTIVE

The aim of the study was to evaluate the influence of developer exhaustion on accuracy of quantitative digital subtraction radiography.

STUDY DESIGN

Six objects, each incorporating a section of dry human mandible, were radiographed with 4 exposure times. Baseline films were processed in fresh solutions, whereas follow-up films were processed in fresh and in increasingly exhausted solutions (ie, 1, 2, and 3 weeks old). Bone loss and bone gain were computer simulated in 17 regions of interest on baseline radiographs. Area and volume of changes in mineralization were measured in subtracted images, obtained by subtraction of baseline from their corresponding follow-up radiographs. Friedman's 2-way analysis of variance by ranks and Wilcoxon signed-rank test were used for statistical analysis.

RESULTS

Because of exhausted developer, bone loss was relatively underestimated from 6.6% to 16.5% (P <.05), whereas bone gain was relatively overestimated from 9.7% to 16.7% (P <.05).

CONCLUSIONS

This in vitro study demonstrates that films for quantitative digital subtraction radiography should be processed in fresh developer or error might be introduced.

The efficacy of caries detection using three intraoral films under different processing conditions

This study compares the diagnostic accuracy of caries detection using Ultra-speed (Eastman Kodak), Ektaspeed (Eastman Kodak) and Ektaspeed Plus (Eastman Kodak) films after they were developed in both new and used processing solutions. Ektaspeed Plus film provided significantly better diagnostic accuracy for small proximal-surface caries limited to the outer third of the dentin than did Ektaspeed film. Ektaspeed Plus film did not differ significantly from Ultra-speed film in aiding in the diagnosis of small carious lesions, and it maintained diagnostic accuracy in used processing solutions. Dentists can offer the X-ray dose-reducing technology of Ektaspeed Plus film to their patients and maintain consistently high diagnostic quality.

Radiographic contrast. A comparative study of three dental X-ray films

OBJECTIVE

To investigate the radiographic contrast of three dental X-ray films (Ultra-speed, Ektaspeed and Ektaspeed Plus, Eastman-Kodak, Rochester, NY, USA).

METHODS

An aluminium stepwedge was radiographed for the objective assessment and a dried human mandibular segment including the teeth for the subjective evaluation. In the objective assessment, contrast was evaluated from the measured optic densities and the results analysed statistically by the Kruskal-Wallis one-way Anova and Mann-Whitney U test. Subjective evaluation was performed by 12 dentists with a range of clinical experience and scores were assigned to five dental and bony structures.

RESULTS

In the objective evaluation there was no significant difference in contrast obtained with the Ultra-speed and Ektaspeed Plus films: both had significantly better contrast than Ektaspeed film. The subjective assessment revealed that the majority of the dentists preferred either Ultra-speed or Ektaspeed Plus films for contrast.

CONCLUSION

Radiographic contrast of Ektaspeed Plus did not differ significantly from Ultra-speed and both were superior to Ektaspeed film.

Base and fog densities of fresh Ektaspeed Plus dental X-ray films

Previous findings with regard to base and fog density of Ektaspeed Plus dental X-ray films have shown increased values compared with Ektaspeed and Ultra-Speed films, but the results are contradictory. The purpose of the present study was to measure base density, using 10 different fixing solutions, and fog density, using 10 different developing solutions at temperatures varying from 16 to 30 degrees C. The 10 developers tested were intended for manual (three), semiautomatic (three), and automatic (four) processing. Base densities were nearly identical for all fixing products (range, 0.190-0.192). One group of six developers showed quite stable fog values for all temperatures (range, 0.190-0.259), whereas another group (four developers) showed increased values at increasing temperatures (range, 0.395-0.438 at 30 degrees C). It is concluded that base density is within the limits of ISO standards for most fixing products but that some developers result in fog densities that are above ISO standard limits at high temperatures.

Densitometric properties of rapid manual processing solutions: abbreviated versus complete rapid processing

Rapid manual processing solutions produce wet, readable radiographs in 1 to 2 min. However, some manufacturers permit time reductions for various processing steps to obtain images even more quickly. Differences in densitometric characteristics and spatial resolution between abbreviated rapid processing (ARP) and complete rapid processing were examined in four rapid manual processing systems on D- and E-speed film. When compared with films processed conventionally in an automatic processor, films processed in rapid manual processing chemistries had more fog and generally lower levels of speed and contrast. ARP radiographs were excessively stained unless they were washed for at least 60 s after fixing. The most severe depreciation in ARP film quality occurred when developing time was reduced by 50%; the complete rapid processing developing time should always be used. E-speed films produced radiographs with comparable densitometric and resolution characteristics to D-speed films for ARP and complete rapid processing techniques while requiring 40% less radiation.

The effect of thin K-edge filters on the image quality of D- and E-speed dental film

The use of K-edge filters and fast speed dental (non-screen) film have been separately shown to reduce the radiation dose imparted during dental radiography. The effect of these on image quality has been unclear. This study objectively examines the effect on image quality of eight film/filter systems: E- and D-speed film and four filter systems (the existing aluminium filter used alone or with erbium, niobium or yttrium). The components of the image quality parameters assessed were contrast, resolution, the minimum perceptible contrast (noise) and the square wave response function. No clinically significant difference in image quality was observed. This was confirmed by subjective assessment of images of an anatomical phantom. It is concluded that the use of faster speed film in addition to K-edge beam filtration has no major effect on the clinical image.

Effects of developer exhaustion on Kodak EKTASPEED Plus, Ektaspeed, and Ultra-speed dental films

In 1994, Eastman Kodak Co. (Rochester, N.Y.) replaced its Ektaspeed film with the EKTASPEED Plus film. The manufacturer claims that one of the advantages of the new film is that it is not strongly affected by exhausted (depleted plus aged) processing solutions. The objective of the experiment was to test this claim. In exhausted solutions, EKTASPEED Plus film lost its speed more rapidly than Ultra-speed film but less rapidly than Ektaspeed film; that is, Ultra-speed film had the most stable speed. EKTASPEED Plus film lost contrast for 2 weeks before stabilizing, whereas Ultra-speed and Ektaspeed films continued to lose contrast for 3 weeks. Overall, EKTASPEED Plus film held its contrast over the other two films. EKTASPEED Plus film stopped increasing its film latitude after 2 weeks, whereas Ultra-speed and Ektaspeed films continued to increase film latitudes. In conclusion, for the three films studied, EKTASPEED Plus maintained the most constant levels of contrast and latitude in progressively exhausted solutions. All three films lost speed in exhausted solutions; EKTASPEED Plus film was the fastest but Ultra-speed film had the most stable speed.

Sensitometric comparison of Kodak EKTASPEED Plus, Ektaspeed, and Ultra-speed Dental Films

In 1994, Eastman Kodak Co. (Rochester, N.Y.) marketed EKTASPEED Plus dental film to combine the advantages of the contrast of Ultra-speed film and the speed of Ektaspeed film. EKTASPEED Plus film uses T-Grain Emulsion technology similar to that used in the manufacture of the light-sensitive indirect exposure Kodak T-Mat film. This study compared the sensitometric properties of Ultra-speed, Ektaspeed, and EKTASEED Plus dental films. EKTASPEED Plus film was faster than Ektaspeed film at all film densities. Ektaspeed film became slower at higher densities and around a density of 1.9 became even slower than the Ultra-speed film. EKTASPEED Plus film had high inherent contrast and narrow exposure latitude similar to that of Ultra-speed film, whereas Ektaspeed film had low inherent contrast and wide exposure latitude. In conclusion, EKTASPEED Plus film had the advantages of the high contrast of Ultra-speed film and the high speed of Ektaspeed film. It maintained its high speed at high densities.

Densitometric comparisons of Ultra-speed, Ektaspeed, and Ektaspeed Plus intraoral films for two processing conditions

This study compared film speed, contrast, exposure latitude, and resolution of Ultra-speed, Ektaspeed, and Ektaspeed Plus films (Eastman Kodak Co., Rochester, N.Y.). Densitometric curves were generated for each film type under processing conditions of fresh and used chemistry to observe their effect on factors associated with diagnostic quality. Ektaspeed Plus film displayed the least variability due to processing condition of any film; it also demonstrated the fastest speed and was twice as fast as Ultra-speed film. Ektaspeed exhibited the greatest relative exposure latitude followed by Ektaspeed Plus and Ultra-speed. Average gradient over a clinically useful range of densities was greatest for Ultra-speed in fresh processing solutions, but greatest for Ektaspeed Plus in used processing solutions. All film types were able to resolve more than 16.6 line pairs per millimeter regardless of processing conditions. The results of this study suggest that dental practitioners who have refrained from using E-speed film because of the sensitivity of this film to variations in processing may now consider providing this dose-reducing technology for their patients with the expectation of obtaining consistent image quality.

Automatic processing: effects of temperature and time changes on the sensitometric properties of light-sensitive films

The effects of changes in the processing temperature and time of automatic processors were studied with three light-sensitive Kodak films: (1) blue-sensitive X-Omat RP film, (2) green-sensitive T-Mat G film, and (3) ultraviolet-sensitive X-Omat duplicating film. Speed and inherent contrast were derived for each of the three films from sensitometric curves at six different temperatures and at five different processing times. The T-Mat G film (T-grain technology) was comparatively less sensitive than conventional films (X-Omat RP) to increases in processing temperature or time. Unlike dental intraoral films, which cannot be processed at low processing time or temperature, the light-sensitive films were of archival storage quality even at a low processing time of 2.5 minutes or at a low processing temperature of 21 degrees C. Therefore the processing time of an automatic processor may be decreased for light-sensitive films.