Optical Behavior of Zirconia-Based Restorations Over Teeth and Implants in the Esthetic Zone: A Clinical Report.

While various zirconia-based alternatives are available today for the restoration of teeth and implants in the esthetic zone, each treatment approach could result in different optical behavior. To clinically demonstrate these differences, this case report describes a rehabilitation in the esthetic zone using several options of teeth- and implant-supported restorations. Conventional veneered zirconia crowns, high-translucent monolithic zirconia crowns, and minimally veneered high-translucent zirconia crowns were proposed and assessed under different light sources before cementation. The patient and clinical team achieved consensus on the minimally veneered high-translucent zirconia crowns, which were then cemented and have performed well over both tooth and implant substrates.

Color stability of repairs on bis-acryl resin submitted to thermal aging and immersion in beverages.

OBJECTIVE: Defects/bubbles can occur during the manufacture of bis-acryl resin provisional restorations, requiring repair or new prosthesis. This study evaluated the color stability of bis-acryl resin specimens repaired, aging, and immersioned in beverages. MATERIAL AND METHODS: Eighty disks were made of bis-acryl resin. Twenty disks were not repaired (BCR), 20 disks were repaired with the same bis-acryl resin (BCR-BCR), 20 disks were repaired with flowable resin (BCR-FR), and 20 disks received an adhesive layer prior to flowable resin repair (BCR-AFR). Coordinates L*a*b* were obtained. Ten disks from each group were thermocycled (5000 cycles) and the others were immersed in coffee with sugar (n = 5) and cola-based soft drinks (n = 5) for 7 days. Color, lightness, chroma, and hue differences were calculated by the CIEDE2000 formula, analyzed by two-way analysis of variance. Multiple comparisons were made with the Tukey's HSD test (α = .05). RESULTS: BCR-FR group presented the highest color differences (5.6) between groups repaired (P < .001). BCR-BCR group showed the smallest color differences (0.9) after aging (P = .003), but the greatest variation between T0 and T1 (about 1 ΔE). BCR-ARF immersed in coffee showed the greatest color differences (20.6) (P < .001). CONCLUSIONS: Aging and immersion altered the colorimetric behavior of repairs, especially after the use of coffee. CLINICAL IMPLICATIONS: Repairs are indicated when defects and bubbles are present in the surface of the bis-acryl resin provisional restorations after its manufacture. However, they may present noticeable color changes, especially when the use of coffee is frequent.

Can Time of Implant Placement influence Bone Remodeling?

Since the alveolar process is tissue "dental dependent," after the extraction of the dental element, this process suffers some degree of atrophy during the healing process, which can be reduced with the installation of immediate implants, aiming to maintain the original bone architecture. The aim of this study was to investigate the influence of the time of implant placement on bone formation around them. Seven dogs were selected and randomly divided into two groups: Group 1, where implants were placed immediately after extraction of two lower premolars without flap elevation, and group 2, where implants were delayed by 4 months after extractions. Each group received 14 implants, and 4 months after the second surgery, the samples were processed and analyzed histomorphometrically. A mean average analysis and the Kruskal-Wallis test (p < 0.05) were performed. The buccal bone-implant contact (BIC) mean average was found larger in immediate implants (42.61%) compared with delayed implants (37.69%). Group 1 had statistically higher outcomes in bone formation and BIC on the buccal bone wall. It was concluded that performing immediate implants with the palatal approach technique and leaving a buccal GAP enables a higher or at least equal rate to BIC and bone area around them, when compared with delayed implants. Actually, the patients and dentists want to do a shorter treatment with satisfactory results, but it is necessary to understand whether different times of implant placement can influence the results and longevity of the treatment.