Crown discoloration induced by endodontic sealers: spectrophotometric measurement of Commission International de I'Eclairage's L*, a*, b* chromatic parameters.

Despite the improvement of endodontic materials, crown discoloration induced by root canal sealers remains a concerning clinical issue. The aim of this study is the measurement of the alterations in CIE L*, a*, b* chromatic parameters of tooth crowns after placement of commonly used and new-generation endodontic sealers in pulp chambers. Eighty intact, fully developed third mandibular molars were randomly assigned in five groups. Crowns were cross-sectioned from the root complex 1 mm below the cement-enamel junction. The internal axial walls of the pulp chambers were debrided and coated with endodontic sealers (Roth-811, AH-26, Guttaflow, Epiphany SE). The apical access was sealed with glass-ionomer cement. The control group was only debrided. Crowns were stored in individually marked vials in standard conditions (100% humidity, 37°C). The spectral reflectance lines were recorded with a UV-Vis spectrophotometer in the visual spectrum. The CIE L*a*b* parameters were obtained by a linked computer software before sealer placement (baseline), after one week, one, three, and six months, respectively. Statistical analysis was performed with two-way mixed ANOVA models. The level of statistical significance was set at p<0.05. With the exception of the control group, experimental groups presented varying chromatic alterations. Among all experimental groups, Roth-811 sealer induced the most severe alterations in CIE L*, a*, b* chromatic parameters, during all observation periods. After root canal obturation, the clinician should be aware of the presence of remaining root canal filling materials. Thorough debridement of the pulp chamber is essential for the prevention of sealer-induced discoloration.

Teeth and gingival display in the premolar area during smiling in relation to gender and age.

There is limited knowledge concerning tooth and gingival display in the maxillary premolar area during smiling. The purpose of this study was to investigate maxillary premolar and associated gingival display during smiling, and to reveal possible differences related to gender and age. The study consisted of 90 males and 113 females (mean age 38 years, s.d. = 13.83) receiving regular dental care. Two pictures of each subject, one with lips in maximum smile, and the other a retracted frontal view, were made. Clinical crown length, tooth and gingival display were measured for the left maxillary premolars. Central incisors and canines were used as controls. anova with Bonferroni post hoc multiple comparisons tests was used to assess any statistically significant impact of gender and age on tooth and gingival display, and determine differences among gender and age groups (at 5% significance level). Premolars were partially visible in more than 80% of the smiles, and displayed more than 65% of their clinical crown length during smiling. The least display (P < 0.001) was recorded for first and the greatest for second premolars. Tooth display was greater in females, but statistically significant only in central incisors (P < 0.05). No significant differences were revealed between age subgroups. Gingival display was greater for premolars compared with both central incisors (P < 0.001) and canines (P < 0.05). Displayed gingiva was found in first and second premolars in 44 and 49% of subjects, respectively. More gingival display was recorded in females and in younger subjects.