Uncleaned Areas Research Articles

Newly Devised Caries Susceptibility Tests and their Clinical Application for Restorative Dentistry

When cavities are prepared in clinical practice, the outline form is generally established by following the law of extension for prevention advocated by G.V. Black, who placed stress on the unclean area and immune area of tooth surfaces. In this case, not much consideration has so far been given to caries immunity of the oral environment, that is, caries susceptibility. So it seems to be reasonable that the concept of caries susceptibility is introduced into the conventional cavity preparation.The purpose of this study is to investigate the proper testing methods for determining individual caries susceptibility which could be an effective measure when preparing the cavity under the law of extension for prevention. Thus, attention was focussed on the acid buffering property of saliva as an environmental factor and the acid solubility of enamel as a host factor.In this article, the effect of storage conditions of saliva on acid buffering capacity was first studied and then a unique method for the buffering capacity test was devised and its availability was examined.The results were as follows;1. Saliva stored for 3 hours in air showed considerably higher pH and acid buffering capacity than saliva stored for 3 hours without air or saliva immediately after collection. In the conventional measurement of the buffering capacity in air, pH values of the salva increase depending upon the amount of stirring and subsequent standing time, and are unstable. A quasi-anaerobic measurement of the buffering capacity was therefore designed.2. A special apparatus with a Beckman pH combination electrode fitted in the piston of the injection syringe was devised. In the measurement, pH of the saliva (1ml) sucked through the injection needle was read (initial pH) and then was again read after suction of 0.1ml of lactic acid and stirring (final pH). Final pH/initial pH was expressed as the value of the acid buffering capacity.3. According to the new method, the pH and the buffering capacity of the same individual were stable with several measurements of different saliva.4. The pH and the buffering capacity of saliva stored for 3 hours without air were the same as those of saliva immediately after collection.5. When the pH and the buffering capacity of saliva of the same individual were determined in the spring and autumn, the values of both salivas did not show any difference.The new method presents good reproducibility of the pH value of the saliva, and proves to be available for the buffering capacity test.

INVESTIGATIONS REGARDING THE HANDS HYGIENE IN THE PERSONNEL MANIPULATING FOOD PRODUCTS

Determinations made: determination of the presence of coliform bacteria /1 ml washing liquid, according to EN ISO 5541/2/1986; determination of the presence of Salmonella/5 ml washing liquid, according to EN ISO 6579/2002; determination of the presence of Staphylococcus coagulazo-positive /4 ml washing liquid, according to EN ISO 6888-1/1999. Through work protocol, following experimental options were set: Vm: Ab, B – the disinfection of the hands of the personnel was made with chloramine solution B 0.5%; Ve1: Ab, B – the disinfection of the hands of the personnel was made with Catiorom solution 0.2%; Ve2: Ab – the disinfection of the hands of the personnel was made with Catiorom solution 0.2% and the HACCP was implemented. Ve2: B – the disinfection of the hands of the personnel was made with Catiorom solution 0.2% and for the sanitation-disinfection, a team trained for this purpose was used. The official valid standards (OHM 976/98) stipulate the absence of germs of the kind Salmonella/5 ml washing liquid, of coliform bacteia/1 ml washing liquid and of Staphylococcus coagulazo-pozitive/4ml washing liquid. From the bacteriological examination of 1024 samples from the workers’ hands, from two cattle slaughtering units, 65 samples (6.3%) have presented coliform bacteria/ml washing liquid of the palm surface. Of those, 9 samples (13.8%) were positive at the beginning of work and 56 samples (86.2%) were positive during work. In the case of staphylococcus coagulazo-pozitive/4 ml washing liquid, 27 samples (2.6%) were positive, all during work. All analyzed samples were negative regarding the presence of the kind Salmonella in 5 ml washing liquid. A high microbiological contamination of the palm surfaces is found in the working personnel during work, especially when performing operations in the unclean area of the slaughterhouse (stunning, bleeding, skinning, scooping and processing of cattle stomachs). After replacing the disinfectant chloramines B 0,5% with Catiorom 0,2% and introducing a new procedure for the optimization of the sanitation, the number of improper samples went down – before the beginning of the work process as well as during work.

Ward floors and other surfaces as reservoirs of hospital infection.

Impression plates from initially clean horizontal surfaces and floor areas in surgical wards showed a rapid accumulation of bacteria, mainly micrococci, which reached a fluctuating equilibrium after about 24 h. A later increase in bacterial contamination (mainly with aerobic sporing bacilli) to a higher equilibrium level after about 14 days occurred on uncleaned areas. Walls, even if left unwashed, acquired very few bacteria, but many were deposited locally when the wall was touched by a subject whose skin carried large numbers of staphylococci; moist exposed plaster was also heavily contaminated.Regular use of a disinfectant (‘Sudol’ 1 in 100) in cleaning a ward floor did not reduce the equilibrium level of bacteria on the floor.The transfer of staphylococci from contaminated to clean areas on the soles of shoes was demonstrated; the use of tacky and disinfectant mats did not appreciably reduce the transfer of bacteria by this route.Staphylococci deposited on a wall by a disperser were shown to be transferred from the contaminated area of wall to the hands of another subject who did not previously carry the organism; this subject was shown to transfer the staphylo-coccus to a wall which he touched.Attempts to redisperse by air movementStaph. aureuswhich had been shed by a disperser or by a contaminated blanket on to the floor surfaces had little effect; neither blowing with a hair dryer nor brisk exercise appeared to lift any of the staphylococci from a vinyl surface, and only small numbers were lifted by these measures from a terrazzo surface.The hazards of infection from the inanimate environment are discussed.