Case: A 31 year old male opioid addict referred to Addiction Rehabilitation Center, an affiliated clinic to Addiction Research Centre for opioid abstinence therapy. He was skinny in a poor condition. He complained of impaired memory, temporary daily agitation, severe weakness, mild paresthesia, impotence and metallic taste. He was also suffered from importunate spastic abdominal cramps and colic pains which have been repeated several times during the last 6 months.

INTRODUCTION: Intrinsic tooth discolorations after endodontic treatment are principally attributed to the composition of necrotic pulp tissue, hemorrhage within the pulp cavity, endodontic medicaments and/or filling materials. Residual sealer left in pulp chamber after obturation can cause discoloration. The objective of this in vitro study was to evaluate coronal discoloration created by AH26 and ZOE sealers after four months.MATERIALS & METHODS: Fifty intact human extracted maxillary central incisors were employed. Access cavities were prepared in all samples and root canals were instrumented; coronal orifices were then sealed using self-cure glass ionomer. The teeth were divided into two experimental groups (n=20) according to utilized sealer in pulp chambers including AH26 and Dorifill (ZOE). The remaining 10 teeth served as negative and positive controls (n=5).The access cavities were sealed with self-cure glass ionomer. Teeth were kept in incubator for four month. Preliminary digital images of the teeth were taken and then compared with those related to 4-month follow-up. The images were assessed using Photoshop software. Data was analyzed using paired t-test and independent samples t-test.RESULTS: The teeth which were filled with AH26 sealer showed significantly greater discoloration than those filled with ZOE sealer (Dorifill) (P<0.05).CONCLUSION: AH26 sealer causes greater discoloration of the crown compared to ZOE sealer. Despite the other disadvantage of AH26 sealer, it seems that Dorifill is more esthetically considerate.

Discoloration remains an unfavourable complication of otherwise successful regenerative endodontic procedure of immature teeth with necrotic pulp. This review presents a critical view on current knowledge of discoloration sources, its treatment and possible preventive modalities, dealing mainly with the use of antibiotics, ethylendiaminotetraacetic acid, calcium hydroxide, mineral trioxide aggregate, calcium silicate cements, sodium hypochlorite and chlorhexidin during regenerative treatment and their possible

Introduction: The selection of porcelain is based on high biocompatibility, endurance, superficial texture and aesthetics. Nevertheless, the innate fracture charateritics of porcelain is the main cause of the intra oral fractures. Electing a suitable porcelain restorative system in terms of stability of color is important. For this reason, this study aimed to examine the color changes of common porcelain repair materials.Methods: Using a silicon mold, 30 pieces of feldspathic porcelain in A3 color, 10mm of diameter and 2 mm of thickness were prepared. The samples were randomly distributed into three groups:Group 1: Porcelain-Silane-Bonding-CompositeGroup 2: Porcelain-Silane-Bonding-Panavia F 2.0-Bonding-Silane-PorcelainGroup 3: Porcelain-Silane-Bonding-Choice 2 -Bonding-Silane-PorcelainThe aging process was accomplished with thermocyling (3000 cycles, 5.55 degree), incubation in 37o and 100o humidity. Thereafter, discoloration was assessed In CIE system via designation of color transforming matrix in MATLAB environment.Results: The average quantitative amount of discoloration at day 0, 90 and 180 were 76.8±0.57, 79.15±0.52, 80.13±0.6 for Choice, 78.03±0.9, 79.42±0.82, 80.17±0.51 for Panavia, and 78.41±1.53, 79.59±0.77, 81.03±0.63 for Composite, respectively. The color changes by the time were significant for the all three groups (p<001).Calculating day 0-180 color changes, mean color differences for Choice, Panavia and Composite groups were 3.33±0.83, 2.13±1.23, and 2.61±1.6, respectively. The color changes did not differ in the studied groups (p<0.133).Conclusions: Post-aging color changes were significant, although all samples had color changes less than 3.5. Considering the clinical significance of color changes of more than 3.5, these results were acceptable and all three restorative materials could reliably be applied in the daily clinical use.

Background and Aim: Shade guide discoloration after disinfection can interfere with the appropriate color selection for dental restorations. Since one of the most important issues for patients is the color of the final restoration, the discoloration of shade guides due to disinfectants will be important. Infection control is a definite and important matter in dentistry. Due to the contradictory results of studies on the effect of disinfectants on shade guide discoloration, this study aimed to examine the discoloration of the Vita classical shade guide by glutaraldehyde disinfectant. Materials and Methods: In this experimental study, samples of A4, B4, C4, and D4 colors were selected from the Vitapan classical shade guide, 10 pieces each (40 samples in total). Three samples of each color were immersed in distilled water as a control while the other seven were immersed in a 2% glutaraldehyde disinfectant solution. The shade pilot spectrophotometer was used for colorimetry, which was performed at baseline and 24, 48, and 72 hours after the immersion. The color of the samples was evaluated based on the CIE Lab system. The data were analyzed with two-way analysis of variance (ANOVA) and Tukey’, s test. Result: The rate of color change (Δ, E) of the samples was higher in the glutaraldehyde group than in distilled water (P<0. 05). In addition, color change in both groups showed a significant difference at different times (P<0. 05). Conclusion: The Vitapan classical color samples discolor by immersion in 2% glutaraldehyde disinfectant after 24, 48, and 72 hours, but this color change is not clinically detectable (Δ, E<1).