This in turn would make the material www.selleckchem.com/products/Lenalidomide.html less translucent, a result of increased scattering.35,36 According to Kolbeck et al,10 the matrix composition combined with the quality of the polymerisation reaction is mainly responsible for the colour stability of veneering composites. According to Matsumura,24 colour stability is affected by the percentage of remaining C=C bonds (%RDB). It has also been shown that composites containing more than 35% of unconverted C=C bonds tend to be highly susceptible to discoloration.37 In a recent study, however,38 no correlation was found between unconverted C=C bonds and discoloration. Colour difference (��E) evaluation using a colorimeter is a repeatable, sensitive and objective method.
There are, however, some limitations concerning the use of colorimeters with different optical configurations as well as the ��edge loss�� phenomenon. Therefore, colour measurement may not be completely accurate.39,40 In the present study, a custom-made specimen holder was used to eliminate the ��edge loss�� phenomenon. In future studies, it would be useful to consider factors such as light scattering, gloss, shade and transparency when assessing overall discoloration of these materials.11,19 CONCLUSIONS According to the results of the present study: No statistically significant differences were found in ��L*, ��a*, ��b* and ��E values among the materials tested. The predominant colour change after accelerated aging was a green-yellow shift for Gradia (��a*=?1.18, ��b*=?0.6), a green-blue shift (��a*=?0.9, ��b*=?0.45) for Signum+, an increase in lightness (��L*=0.
75) and green shift (��a*=?1.3) for HFO and an increase in lightness (��L*=2.06) and green-yellow shift (��a*=?1.3, ��b*=0.6) for Adoro. Colour changes after accelerated aging were within clinically acceptable ranges (��E<3.3) for all the materials tested.
The control of dental biofilm is one of the cornerstones of preventive dentistry and can be achieved by mechanical means, use of chemical agents, or a combination of the two.1 Mouth-washes are used as adjuvant agents in daily oral hygiene routine, aiding in the chemical control of dental biofilm. In Brazil, most mouthwashes are freely available at pharmacies, drugstores, supermarkets, and other commercial establishments and usually do not require a prescription from a dentist, making these products readily available to children and adults.
The indiscriminate use of mouthwashes by the general population has generated concern because the presence of acid components in their formulations could make the products potentially erosive to hard dental tissue over time.2 Dental erosion is the progressive and irreversible loss of tooth enamel as a result of chemical processes not involving Brefeldin_A bacterial action.3 Previous studies have demonstrated that several mouthwashes available in the Brazilian2,4 and UK5 markets present low endogenous pH. A pH equal to or less than 5.