EFFECT OF CLOVE AND CHLORHEXIDINE DISINFECTANT SOLUTIONS ON DIMENSIONAL ACCURACY AND IMPACT STRENGTH OF HEAT CURE ACRYLIC DENTURE BASE MATERIAL

Background: Heat-cured acrylic resin (PMMA) is the most commonly used material for denture bases because of its favorable properties. However, dentures easily accumulate microbes so maintaining a clean denture is very important to preserve oral health. A chemical or herbal immersed denture cleanser is the most widely used method by patients. The goal was to assess the efficiency of two disinfection solutions, one chemical (chlorhexidine digluconate 0.20% CHX) and the other ethanol herbal extract (clove), on the dimensional accuracy and impact strength of heat-cure acrylic-resin material. 

Materials and Methods: The study design was divided into two main groups, the first was dimensional accuracy (I) which had 24 specimens of heat cure acrylic material as the same specimen was used in each subgroup measurement for this test while the second was impact streagth (II) which had 56 specimens. These main groups were divided to three subgroups: first before immersion, for measuered impact streangth with (n=8), while for dimensional accuracy all 24 specimens was measured and the second subgroup with (n=8) for immersion of specimens in the three disinfectant solutions (CHX, clove, and distilled water, D.W. as a control group) separately for 3 nights then 7 night. 

Results:For the dimensional accuracy, the results show that dimensional reduction happened mostly between immersion and baseline measurement rather than during the two immersion periods. The mean dimensional accuracy before immersion showed 102.57mm, this value decreased to 102.05mm, 101.98mm after 3 nights and 7 nights sequencely with p-value below 0.0001, while the measurements of various disinfectant solutions at identical time showed the mean with 101.62mm, 101.63mm for CHX and 103.23mm,103.44mm for clove in 7 and 3 nights respectively and an overall p-value of 0.2905 which showed no statistically significant difference between the solutions. Whereas the result show that impact strength maintained a constant level throughout the observed period, the mean value before immersion was 0.058 kJ/m2 , while 0.059kJ/m2 , 0.059kJ/m2 after 3 and 7 nights of immersion with p-value of 0.7318, 0.7849 sequencely with no significant difference, while the groups showed highly significant differences between them (p < 0.0001). The pairwise analysis showed that the clove group had significantly higher impact strength values than the CHX group (p < 0.0001). 

Conclusion:The clove solution provided the best balance of safety and performance, showing the least negative impact on the resin’s physical properties while supporting both dimensional accuracy and fracture resistance of heat cured acrylic-resin material followed by chlorhexidine