Effect of Disinfection on Some Mechanical Properties of Polycarbonate Base Material
Background: Dentists face a variety of serious challenges, including the need for ideal material in order to deliver successful dental care to patients. To produce an effective prosthesis with satisfactory appearances these materials should be biologically compatible, readily usable, inexpensive, and easy to manipulate with regulated technological procedures. Removable prosthodontics entails the use of a variety of tools and multipurpose products that are difficult to sterilize or clean, such as prostheses, impressions, and stone casts, which increases the risk of cross-contamination between both the dental clinic and the laboratory.
Materials and Methods: Three NAOCL concentrations (0.25%,0.5% and 0.75 %) were used as determined by the pilot study, which yielded the most suitable results. A total of 200 sample were prepare and divided into 3 experimental group and a control group (2%chlorhexidine,0.25% and 0.5% NAOCL). Each group was subdivided into five identical subgroups. For each subgroup, ten specimens were utilized for each test (elongation percentage, shore D hardness, roughness, impact, color change).
Results: The results of the tests showed significant decrease of Impact strength of the polycarbonate after immersion in (2% chlorhexidine) and it continuous decrease in (0.25% NAOCL) while the lowest mean value was for the (NAOCL 0.5%). The results of surface hardness showed significant slightly increase with (2% chlorhexidine) and decreased with (0.25% NAOCL), (NAOCL 0.5%) respectively. The results of surface roughness showed slightly increased values in (2% chlorhexidine) when compared to control group while increase when immersion in (0.25% NAOCL), (0.5% NAOCL) concentration respectively. The percent of elongation test showed the polycarbonate non-effected when immersed in (2% chlorhexidine) and decrease when immersed in (0.25% NAOCL), (0.5% NAOCL) concentration respectively. The results of color stability showed increased values in (2% chlorhexidine) when compared to control group and continuous increase when immersion in (0.25%NAOCL), (0.5% NAOCL) concentration respectively.
Conclusion: The polycarbonate resin material can be safely immersed in (2% chlorhexidine) disinfectant solution without any damaging effect on surface hardness, surface roughness, percent of elongation and color stability. As well, immersion in (2% chlorhexidine) was preferable than NAOCL disinfectant solution in comparison to the control group.